Advanced polymeric biomaterials
Hybrid polymeric biomaterials
Peptide/polymers hydrid biomaterials
About the project:
We are working on different types of hybrid materials, including degradable polymers associated with peptides and/or biomacromolecules.
The induction of bioactivity by peptides or natural macromolecules is done in different ways:
– Creation of covalent networks with degradable polymers to obtain bioactive hybrid materials. These networks are micro or nanostructured by electrospinning or 3D printing to obtain nanofibres or more complex shapes for many applications such as soft tissue or meniscus regeneration
– the design of monomers containing peptide sequences and their polymerisation to provide a new class of peptide-based copolymers.
Contact:
Students:
Collaborations:
Pr Subra et Pr Amblard (IBMM-peptides, UMR 5247), Sing Yian Chew (NTU, Singapore)
Funding: –
PhD Program (Doctoral school, University of Montpellier), Algerian Excellence Scholarship
Peptide-guided self-assembly of polyethylene glycol-b-poly(ε-caprolactone-g-peptide) block copolymers
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Eur. Pol. J. 176, 111386 (2022)
Ayman El Jundi, Matthias Mayor, Enrique Folgado, Chaimaa Gomri, Belkacem Tarek Benkhaled, Arnaud Chaix, Pascal Verdie, Benjamin Nottelet, Mona Semsarilar
ABSTRACT
Biodegradable poly(ethylene glycol)-b-poly(ε-caprolactone-g-peptide) (PEG-b-PCL-g-peptide) copolymers were synthesized using a combination of ring opening polymerization and thiol-yne photoaddition of peptides on the alkyne functional PCL block. The peptides Phe-Phe, Tyr-Tyr and Arg-Gly-Asp were selected based on the expected interactions (Pi-stacking, H-bonding, electrostatic). The self-assembly of these copolymers was studied via testing the effect of various parameters such as the nature of the solvent and non-solvant as well as their ratio,mixing method, temperature and concentration. Structures obtained by varying these parameters were characterised using transmission electron microscopy (TEM) and dynamic light scattering (DLS). Spherical and lamellar structures (oval leaf-shaped) of different sizes were identified as a function of the conditions. The role of the crystallisation and of the peptides was highlighted with more defined and stable structures obtained for Tyr-Tyr functional copolymers.
Direct synthesis of peptide-containing silicone. A new way for bioactive materials
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Chem. Eur. J. 10.1002/chem.202001571
Ahmad Mehdi, Martin Julie, Mohammad Wehbi, Cecile Echalier, Sylvie hunger, Audrey Bethry, Xavier garric, coline Pinese, jean Martinez, Lubomir vezenkov, and gilles subra
ABSTRACT
A simple and efficient way to synthesize peptide-containing silicone materials is described. Silicone oils containing a chosen ratio of bioactive peptide sequences were prepared by acid-catalyzed copolymerization of dichlorodimethylsilane, hybrid dichloromethyl peptidosilane and either Si-vinyl or Si-H functionalized monomers. Functionalized silicone oils were first obtained and then after hydrosilylation cross-linking, bioactive PDMS based materials were straightforward obtained. The introduction of an antibacterial peptide yields PDMS materials showing an interesting activity against Staphylococcus Aureus. In the same way, RGD ligands-containing PDMS demonstrated improved cell adhesion properties. This generic method was fully compatible with the stability of peptides and thus opened the way to the synthesis of a wide range of biologically active silicones.
Turning peptides into bioactive nylons
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Eur. Polym. J. 2020, 135, 109886.
Said Jebors*, Coline Pinese*, Titouan Montheil*, Audrey Bethry, Simon Verquin, Louise Plais, Marie Moulin, Chloé Dupont, Xavier Garric, Ahmad Mehdi, Jean Martinez, Gilles Subra
ABSTRACT
New synthetic textiles with physical and/or biological properties are increasingly used in medical applications. While a simple textile coating is usually carried out to obtain biological properties, covalent grafting should be considered for long-term applications. Herein, we have developed a new hybrid bioactive nylon whose synthesis involves a peptide sequence with a diacyl derivative. Numerous types of peptide-nylons were prepared by varying the molar percentage (0.1 %, 1 % and 10%) and orientation of the peptide in the polymer backbone. Nylons incorporating antibacterial peptides significantly inhibited S. aureus proliferation whereas nylons functionalized with cell-adhesive peptide enhanced the proliferation of L929 fibroblast. These results show that the incorporation of the peptides directly into the nylon skeleton is efficient and provides biological properties that suggest new ways of functionalizing biomedical textiles.
Bioactive peptides grafted silicone dressings: A simple and specific method
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Materials Today Chemistry 4, 73–83 (2017)
Pinese, C., Jebors, S., Stoebner, P. E., Humblot, V., Verdié, P., Causse, L., Garric, X., Taillades, H., Martinez, J., Mehdi, A. & Subra, G
ABSTRACT
The need for bioactive dressings increases with the population aging and the prevalence of chronic diseases. In contrast, there are very few dressings on the market which are designed to display a chosen bioactivity. In this context, we investigated the surface-functionalization of silicone wound dressing with bioactive peptides. One of the challenges was to avoid multistep grafting reactions involving catalysts, solvents or toxic reagents, which are not suitable for the fabrication of medical devices at an industrial scale. In the other hand, a covalent bonding was necessary to avoid the loss of the biological effect by progressive removal of the peptide in biological fluids generated by the wound. To solve these limitations, we developed a strategy allowing an easy and direct functionalization of silicone. This strategy relies on hybrid silylated bioactive peptides, which chemoselectively react with plasma-activated silicone surfaces. We synthesized three hybrid peptides with wound healing properties, which were grafted on commercially available silicone dressings Cerederm® and Mepitel®. Grafted dressings were evaluated in vitro and enabled a quicker scare recovery and extracellular matrix deposition with human dermal fibroblasts. These results were confirmed by in vivo studies showing an enhanced wound-healing of the pig skin. By this simple method, we transformed inert dressing into bioactive dressing which showed properties of wound healing.
Nanocomposites:
Nanocomposites for bone regeneration
About the project:
Contact:
Students:
Collaborations:
Prof. Combes (CIRIMAT, Toulouse), Prof. Oliva (University of Naples), Prof. Malinconico (IPCB, Naples) Dr. Jérémy Soulié (CIRIMAT, Toulouse)
Funding:
Carnot Balard Cirimat
ANR
Well-defined polyester-grafted silica nanoparticles for biomedical applications: Synthesis and quantitative characterization
Lagarrigue P., Soulié J., Grossin D., Dupret-Bories A., Combes C., Darcos V.
ABSTRACT
Polyester-based composites with silica nanoparticles fillers are promising candidates as biomaterials due to improved mechanical and biological properties. However, nanofillers use generally leads to an inhomogeneous distribution inside the polymer matrix because of agglomeration, decreasing composites overall performances. To improve nanofillers dispersion, the aim of this study is to prepare and characterize poly(D,L lactide) grafted silica nanoparticles using “grafting to” method and to quantify the amount of grafted poly(D,L lactide). Firstly, well-defined N hydroxysuccinimide ester poly(D,L lactide)s were synthetized through a new pathway. Then, amino-functionalized silica nanoparticles were grafted with those customized polyesters yielding an amide covalent bond between both reagents. Such PDLLA grafted nanoparticles were precisely characterized and the grafting amount was quantified using a dual approach based on TGA and FTIR analysis. The synthesis and the characterization methods developed constitute a robust and reproducible way to design well-defined polymer grafted silica nanoparticles that could be used as nanofillers in polymer matrix nanocomposites for biomedical
New synthesis method of HA/P(D,L)LA composites: study of fibronectin adsorption and their effects in osteoblastic behavior for bone tissue engineering
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Journal of Materials Science: Materials in Medicine (2016), 27(9), 1-10
Yala,S., Boustta,M; Gallet, O; Hindie, M; Carreiras, F; Benachour, H; Sidane, D; Khireddine, H.
ABSTRACT
A novel synthetic method to synthesize hydroxyapatite/poly (D,L) lactic acid biocomposite is presented in this study by mixing only the precursors hydroxyapatite and (D,L) LA monomer without adding neither solvent nor catalyst. Three compns. were successfully synthesized with the wt. ratios of 1/1, 1/3, and 3/5 (hydroxyapatite/(D,L) lactic acid), and the grafting efficiency of poly (D,L) lactic acid on hydroxyapatite surface reaches up to 84 %. SEM and Fourier transform IR spectroscopy showed that the hydroxyapatite particles were successfully incorporated into the poly (D,L) lactic acid polymer and X ray diffraction anal. showed that hydroxyapatite preserved its crystallinity after poly (D,L) lactic acid grafting. Differential scanning calorimetry shows that Tg of hydroxyapatite/poly (D,L) lactic acid composite is less than Tg of pure poly (D,L) lactic acid, which facilitates the shaping of the composite obtained. The addn. of poly (D,L) lactic acid improves the adsorption properties of hydroxyapatite for fibronectin extracellular matrix protein. Furthermore, the presence of poly (D,L) lactic acid on hydroxyapatite surface coated with fibronectin enhanced pre-osteoblast STRO-1 adhesion and cell spreading. These results show the promising potential of hydroxyapatite/poly (D,L) lactic acid composite as a bone substitute material for orthopedic applications and bone tissue engineering.
Functionalized PCL/HA nanocomposites as microporous membranes for bone regeneration
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Mat. Sci. Eng. C-Mater. Biol. Appl. 48, 457–468 (2015)
Basile, M. A., d’Ayala, G. G., Malinconico, M., Laurienzo, P., Coudane, J., Nottelet, B., Della Ragione, F. & Oliva, A.
ABSTRACT
In the present work, microporous membranes based on poly(ε-caprolactone) (PCL) and PCL functionalized with amine (PCL-DMAEA) or anhydride groups (PCL-MAGMA) were realized by solvent–non solvent phase inversion and proposed for use in Guided Tissue Regeneration (GTR). Nanowhiskers of hydroxyapatite (HA) were also incorporated in the polymer matrix to realize nanocomposite membranes. Scanning Electron Microscopy (SEM) showed improved interfacial adhesion with HA for functionalized polymers, and highlighted substantial differences in the porosity. A relationship between the developed porous structure of the membrane and the chemical nature of grafted groups was proposed. Compared to virgin PCL, hydrophilicity increases for functionalized PCL, while the addition of HA influences significantly the hydrophilic characteristics only in the case of virgin polymer. A significant increase of in vitro degradation rate was found for PCL-MAGMA based membranes, and at lower extent of PCL-DMAEA membranes. The novel materials were investigated regarding their potential as support for cell growth in bone repair using multipotent mesenchymal stromal cells (MSC) as a model. MSC plated onto the various membranes were analyzed in terms of adhesion, proliferation and osteogenic capacity that resulted to be related to chemical as well as porous structure. In particular, PCL-DMAEA and the relative nanocomposite membranes are the most promising in terms of cell-biomaterial interactions.
Nanocomposites for theranostic and soft/hard tissue interfacing
About the project:
This project aims at combining nanostructured polymers with inorganic particles (eg. SPIONs, dopped hydroxyapatite nanoparticles etc.) in a controlled manner to provide well defined interfaces as well as imaging opportunities.
Contact:
Students:
Collaborations:
Dr. Laurencin, Dr. Guari, Prof. Larionova (IMNO, ICGM UMR 5253), Dr. Lemaire (MINT, Inserm 1066 – CNRS 6021), Dr. Franconi (platform PRISM), Prof. Gilbert (Renssaeler Institute, Troy, USA)
Funding:
Labex Chemisyst, France Life Imafing
Long-term in vivo performances of polylactide / iron oxide nanoparticles core-shell fibrous nanocomposites as MRI-visible magneto-scaffolds
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Biomat. Sci. 9, 6203–6213 (2021)
Awada H., Seene S., Laurencin D., Lemaire L., Franconi F., Bernex F., Bethry A., Garric X., Guari Y., Nottelet B.
ABSTRACT
There is a growing interest in magnetic nanocomposites in biomaterials science. In particular, nanocomposites that combine poly(lactide) (PLA) nanofibers and super paramagnetic iron oxide nanoparticles (SPIONs), which can be obtained by either electrospinning of a SPIONs suspension in PLA or by precipitating SPIONs at the surface of PLA, are well documented in the literature. However, these two classical processes yield nanocomposites with altered materials properties, and their long-term in vivo fate and performances have in most cases only been evaluated over short periods of time. Recently, we reported a new strategy to prepare well-defined PLA@SPIONs nanofibers with a quasi-monolayer of SPIONs anchored at the surface of PLA electrospun fibers. Herein, we report on a 6-month in vivo rat implantation study with the aim of evaluating the long-term magnetic resonance imaging (MRI) properties of this new class of magnetic nanocomposites, as well as their tissue integration and degradation. Using clinically relevant T2-weighted MRI conditions, we show that the PLA@SPIONs nanocomposites are clearly visible up to 6 months. We also evaluate here by histological analyses the slow degradation of the PLA@SPIONs, as well as their biocompatibility. Overall, these results make these nanocomposites attractive for the development of magnetic biomaterials for biomedical applications.
Assessing the combination of magnetic field stimulation, iron oxide nanoparticles, and aligned electrospun fibers for promoting neurite outgrowth from dorsal root ganglia in vitro
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Acta Biomaterialia 131, 302–313 (2021)
Funnell J.L., Ziemba A.M., Nowak J.F., Awada H., Prokopiou N., Samuel J., Guari Y., Nottelet B., Gilbert R.J.
ABSTRACT
Magnetic fiber composites combining superparamagnetic iron oxide nanoparticles (SPIONs) and electrospun fibers have shown promise in tissue engineering fields. Controlled grafting of SPIONs to the fibers post-electrospinning generates biocompatible magnetic composites without altering desired fiber morphology. Here, for the first time, we assess the potential of SPION-grafted scaffolds combined with magnetic fields to promote neurite outgrowth by providing contact guidance from the aligned fibers and mechanical stimulation from the SPIONs in the magnetic field. Neurite outgrowth from primary rat dorsal root ganglia (DRG) was assessed from explants cultured on aligned control and SPION-grafted electrospun fibers as well as on non-grafted fibers with SPIONs dispersed in the culture media. To determine the optimal magnetic field stimulation to promote neurite outgrowth, we generated a static, alternating, and linearly moving magnet and simulated the magnetic flux density at different areas of the scaffold over time. The alternating magnetic field increased neurite length by 40% on control fibers compared to a static magnetic field. Additionally, stimulation with an alternating magnetic field resulted in a 30% increase in neurite length and 62% increase in neurite area on SPION-grafted fibers compared to DRG cultured on PLLA fibers with untethered SPIONs added to the culture media. These findings demonstrate that SPION-grafted fiber composites in combination with magnetic fields are more beneficial for stimulating neurite outgrowth on electrospun fibers than dispersed SPIONs.
Well-defined polyester-grafted silica nanoparticles for biomedical applications: Synthesis and quantitative characterization
Lagarrigue P., Soulié J., Grossin D., Dupret-Bories A., Combes C., Darcos V.
ABSTRACT
Polyester-based composites with silica nanoparticles fillers are promising candidates as biomaterials due to improved mechanical and biological properties. However, nanofillers use generally leads to an inhomogeneous distribution inside the polymer matrix because of agglomeration, decreasing composites overall performances. To improve nanofillers dispersion, the aim of this study is to prepare and characterize poly(D,L lactide) grafted silica nanoparticles using “grafting to” method and to quantify the amount of grafted poly(D,L lactide). Firstly, well-defined N hydroxysuccinimide ester poly(D,L lactide)s were synthetized through a new pathway. Then, amino-functionalized silica nanoparticles were grafted with those customized polyesters yielding an amide covalent bond between both reagents. Such PDLLA grafted nanoparticles were precisely characterized and the grafting amount was quantified using a dual approach based on TGA and FTIR analysis. The synthesis and the characterization methods developed constitute a robust and reproducible way to design well-defined polymer grafted silica nanoparticles that could be used as nanofillers in polymer matrix nanocomposites for biomedical
Controlled Anchoring of Iron Oxide Nanoparticles on Polymeric Nanofibers: Easy Access to Core@Shell Organic−Inorganic Nanocomposites for Magneto-Scaffolds
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ACS Appl. Mater. Interfaces 11, 9519–9529 (2019)
Awada H., Al Samad A., Laurencin D., Gilbert R., Dumail X., El Jundi A., Bethry A., Pomrenke R., Johnson C., Lemaire L., Franconi F., Félix G., Larionova J., Guari Y., Nottelet B.
ABSTRACT
Composites combining superparamagnetic iron oxide nanoparticles (SPIONs) and polymers are largely present in modern (bio)materials. However, while SPIONs embedded in polymer matrices are classically reported, the mechanical and degradation properties of the polymer scaffold are impacted by the SPIONs. Therefore, the controlled anchoring of SPIONs onto polymer surfaces is still a major challenge. Herein, we propose an efficient strategy for the direct and uniform anchoring of SPIONs on the surface of functionalized-polylactide (PLA) nanofibers via a simple free ligand exchange procedure to design PLA@SPIONs core@shell nanocomposites. The resulting PLA@SPIONs hybrid biomaterials are characterized by electron microscopy (SEM and TEM) and EDXS analysis, to probe the morphology and detect elements present at the organic/inorganic interface, respectively. A monolayer of SPIONs with a complete and homogeneous coverage is observed on the surface of PLA nanofibers. Magnetization experiments show that magnetic properties of the nanoparticles are well-preserved after their grafting on the PLA fibers and that the size of the nanoparticles does not change. The absence of cytotoxicity, combined with a high sensitivity of detection in MRI both in vitro and in vivo make these hybrid nanocomposites attractive for the development of magnetic biomaterials for biomedical applications.
Degradable elastomers and biomaterials mechanical behaviours:
Resorbable elastomers for medical applications
About the project:
This project is dedicated to the design and synthesis of biomaterials that exhibit mechanical properties of interest for soft tissue engineering like elastomeric or shape-memory properties.
Contact:
Students:
Collaborations:
Dr. Chagnon & Prof. Favier (TIMC-IMAG, UMR 5525), Dr . David et Dr. Caillol (IAM, ICGM UMR 5253)
Funding:
PhD Program (Doctoral school, University of Montpellier), Financement SATT-AxLR Elastar, ANR Openn.
Dual-crosslinked degradable elastomeric networks with self-healing properties: bringing multi(catechol) star block copolymers into play
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ACS Appl. Mater. Interfaces 15, 2077-2091 (2023)
Mathilde Grosjean, Louis Gangolphe, Stéphane Dejean, Sylvie Hunger, Audrey Bethry, Frédéric Bossard, Xavier Garric, Benjamin Nottelet
ABSTRACT
In the biomedical field, degradable chemically crosslinked elastomers are interesting materials for tissue engineering applications since they present rubber-like mechanical properties matching with those of soft tissues and are able to preserve their 3D structure over degradation. Their use in biomedical applications requires surgical handling and implantation that can be source of accidental damages responsible for loss of properties. Therefore, their inability to be healed after damage or breaking can be a major drawback. In this work, biodegradable dual-crosslinked networks that exhibit fast and efficient self-healing properties at 37 °C are designed. Self-healable dual-crosslinked (chemically and physically) elastomeric networks are prepared from two methods. The first approach is based on the mix of hydrophobic PEG-PLA star-shaped copolymers functionalized either with catechol or methacrylate moieties. In the second approach, hydrophobic bifunctional PEG-PLA star-shaped copolymers with both catechol and methacrylate on their structure are used. In the two systems the supramolecular network is responsible for the self-healing properties thanks to the dynamic dissociation/re-association of the numerous hydrogen bonds between the catechol groups, whereas the covalent network ensures mechanical properties similar to pure methacrylate networks. The self-healable materials display mechanical properties that are compatible with soft tissues and exhibit linear degradation because of the chemical crosslinks. The performances of networks from mix copolymers vs. bifunctional copolymers are compared and demonstrate the superiority of the later. The biocompatibility of the materials is also demonstrated and confirm the potential of these degradable self-healable elastomeric networks to be used for the design of temporary medical devices.
Bioresorbable bilayered elastomers/hydrogels constructs with gradual interfaces for the fast actuation of self-rolling tubes
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ACS Appl. Mater. Interfaces 14, 43719–43731 (2022)
Mathilde Grosjean, Sidzigui Ouedraogo, Stéphane Déjean, Xavier Garric, Valeriy Luchnikov, Arnaud Ponche, Noëlle Mathieu, Karine Anselme, Benjamin Nottelet
ABSTRACT
In the biomedical field, self-rolling materials provide interesting opportunities to develop medical devices suitable for drug or cell encapsulation. However, to date a major limitation for medical applications is the use of non-biodegradable and non-biocompatible polymers that are often reported for such applications, or the slow actuation witnessed with degradable systems. In this work, biodegradable self-rolling tubes that exhibit a spontaneous and rapid actuation when immersed in water are designed. Photo-crosslinkable hydrophilic and hydrophobic PEG-PLA star-shaped copolymers are prepared and used to prepare bilayered constructs. Thanks to the discrete mechanical and swelling properties of each layer and the cohesive/gradual nature of the interface, the resulting bilayered films are able to self-roll in water in less than 30 seconds depending on the nature of the hydrophilic layer and on the shape of the sample. The cytocompatibility and degradability of the materials are demonstrated and confirm the potential of such self-rolling resorbable biomaterials in the field of temporary medical devices.
Degradable multi(aryl-azide) star copolymer as universal photo-crosslinker for elastomeric scaffolds
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Mater. Today Chem. 12, 209-221, (2019)
Gangolphe L., Déjean S., Bethry A., Hunger S., Pinese C., Garric X., Bossard F., Nottelet B.
ABSTRACT
Degradable elastomers with elastic properties close to those of soft-tissues are necessary for tissue-engineering. Most degradable elastomers developed so far are based on functional low molecular weight pre-polymers that are combined with molecular crosslinkers to yield the elastomeric 3D networks. To overcome this limitation, we present in this work the concept of star-shaped macromolecular multi(aryl-azide) photo-crosslinker that has the ability to efficiently crosslink any polymer containing C-H bonds independently of its molecular weight and without the need for pre-functionalization. This concept of universal crosslinking agent is illustrated with a star-shaped block copolymer composed of an 8-arm poly(ethylene glycol) core and poly(lactide) side arms functionalized with aryl-azide moieties (PEG8arm-PLA-fN3). It was selected due to its macromolecular nature that allows for an easy processing of electrospun photo-crosslinked scaffolds while making it possible to adapt its chemical nature with the one of the polymer matrix. A parameter study is first carried out on PEG8arm-PLA-fN3 / PLA-Pluronic®-PLA films to evaluate the impact of the polymers molecular weight, PEG/PLA ratios, and UV irradiation conditions on the crosslinking efficiency. This study confirms that high crosslinking efficiencies can be obtained with PEG8arm-PLA-fN3 (60%) compared to commercially availabe bis(aryl-azide) photo-crosslinker (below 15%). Optimal conditions are then used to yield electrospun microfibers (1-2 µm) crosslinked with PEG8arm-PLA-fN3 resulting in biocompatible and highly elastomeric scaffolds (ε_y>100%) compared to uncrosslinked scaffolds(ε_y<10%). In addition, we show that the degradation rate can be controlled over time depending on the blend content of PEG8arm-PLA-fN3. Taken together, these results demonstrate the potential of macromolecular multi(aryl-azide) photo-crosslinkers to develop original degradable elastomeric scaffolds for soft-tissue reconstruction.
Redox Reducible and Hydrolytically Degradable PEG-PLA Elastomers as Biomaterial for Temporary Drug-Eluting Medical Devices.
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Macromolecular Bioscience 16, 1792–1802 (2016)
Rupnik, S., Buwalda, S., Dejean, S., Bethry, A., Garric, X., Coudane, J. & Nottelet, B
ABSTRACT
With the aim to develop biomaterials for temporary medical devices, a series of novel reducible and/or degradable elastomers has been prepared from PLA‐b‐PEG‐b‐PLA copolymers photo‐crosslinked with diallyl sulfide or pentaerythritol tetrakis(3‐mercaptopropionate). Thermal and mechanical properties, including elastic limit and Young modulus, are assessed. Degradation is then evaluated under standard hydrolytic conditions. Reducibility of a selected elastomer is then illustrated using 2‐mercaptoethanol or glutathione as reducing agents. The redox‐sensitivity of the selected elastomer and the possibility to modulate the degradability are shown. Considering drug‐eluting elastomeric devices applications, anti‐inflammatory drug ibuprofen loading is illustrated with the two simplest elastomer formulations. A rapid or slow linear release is observed as a function of the low or high molecular weight of the triblock pre‐polymers. Finally, the cytocompatibility of the degradable elastomers is assessed with regard to their potential to favor or inhibit L929 murine fibroblasts proliferation as a function of the hydrophilicity/hydrophobicity of the triblock copolymers.
Evaluation of biomaterials mechanical behaviours
About the project:
This project is dedicated to the design and synthesis of biomaterials that exhibit mechanical properties of interest for soft tissue engineering
Contact:
Students:
Collaborations:
Funding:
Dual-crosslinked degradable elastomeric networks with self-healing properties: bringing multi(catechol) star block copolymers into play
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ACS Appl. Mater. Interfaces 15, 2077-2091 (2023)
Mathilde Grosjean, Louis Gangolphe, Stéphane Dejean, Sylvie Hunger, Audrey Bethry, Frédéric Bossard, Xavier Garric, Benjamin Nottelet
ABSTRACT
In the biomedical field, degradable chemically crosslinked elastomers are interesting materials for tissue engineering applications since they present rubber-like mechanical properties matching with those of soft tissues and are able to preserve their 3D structure over degradation. Their use in biomedical applications requires surgical handling and implantation that can be source of accidental damages responsible for loss of properties. Therefore, their inability to be healed after damage or breaking can be a major drawback. In this work, biodegradable dual-crosslinked networks that exhibit fast and efficient self-healing properties at 37 °C are designed. Self-healable dual-crosslinked (chemically and physically) elastomeric networks are prepared from two methods. The first approach is based on the mix of hydrophobic PEG-PLA star-shaped copolymers functionalized either with catechol or methacrylate moieties. In the second approach, hydrophobic bifunctional PEG-PLA star-shaped copolymers with both catechol and methacrylate on their structure are used. In the two systems the supramolecular network is responsible for the self-healing properties thanks to the dynamic dissociation/re-association of the numerous hydrogen bonds between the catechol groups, whereas the covalent network ensures mechanical properties similar to pure methacrylate networks. The self-healable materials display mechanical properties that are compatible with soft tissues and exhibit linear degradation because of the chemical crosslinks. The performances of networks from mix copolymers vs. bifunctional copolymers are compared and demonstrate the superiority of the later. The biocompatibility of the materials is also demonstrated and confirm the potential of these degradable self-healable elastomeric networks to be used for the design of temporary medical devices.
Degradable Bioadhesives Based on Star PEG–PLA Hydrogels for Soft Tissue Applications
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Biomacromolecules XX, XX (2022)
Mathilde Grosjean, Edouard Girard, Audrey Bethry, Grégory Chagnon, Xavier Garric, Benjamin Nottelet
ABSTRACT
Tissue adhesives are interesting materials for wound treatment as they present numerous advantages compared to traditional methods of wound closure such as suturing and stapling. Nowadays, fibrin and cyanoacrylate glues are the most widespread commercial biomedical adhesives, but these systems display some drawbacks. In this study, degradable bioadhesives based on PEG–PLA star-shaped hydrogels are designed. Acrylate, methacrylate, and catechol functional copolymers are synthesized and used to design various bioadhesive hydrogels. Various types of mechanisms responsible for adhesion are investigated (physical entanglement and interlocking, physical interactions, chemical bonds), and the adhesive properties of the different systems are first studied on a gelatin model and compared to fibrin and cyanoacrylate references. Hydrogels based on acrylate and methacrylate reached adhesion strength close to cyanoacrylate (332 kPa) with values of 343 and 293 kPa, respectively, whereas catechol systems displayed higher values (11 and 19 kPa) compared to fibrin glue (7 kPa). Bioadhesives were then tested on mouse skin and human cadaveric colonic tissue. The results on mouse skin confirmed the potential of acrylate and methacrylate gels with adhesion strength close to commercial glues (15–30 kPa), whereas none of the systems led to high levels of adhesion on the colon. These data confirm that we designed a family of degradable bioadhesives with adhesion strength in the range of commercial glues. The low level of cytotoxicity of these materials is also demonstrated and confirm the potential of these hydrogels to be used as surgical adhesives.
Bioresorbable bilayered elastomers/hydrogels constructs with gradual interfaces for the fast actuation of self-rolling tubes
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ACS Appl. Mater. Interfaces 14, 43719–43731 (2022)
Mathilde Grosjean, Sidzigui Ouedraogo, Stéphane Déjean, Xavier Garric, Valeriy Luchnikov, Arnaud Ponche, Noëlle Mathieu, Karine Anselme, Benjamin Nottelet
ABSTRACT
In the biomedical field, self-rolling materials provide interesting opportunities to develop medical devices suitable for drug or cell encapsulation. However, to date a major limitation for medical applications is the use of non-biodegradable and non-biocompatible polymers that are often reported for such applications, or the slow actuation witnessed with degradable systems. In this work, biodegradable self-rolling tubes that exhibit a spontaneous and rapid actuation when immersed in water are designed. Photo-crosslinkable hydrophilic and hydrophobic PEG-PLA star-shaped copolymers are prepared and used to prepare bilayered constructs. Thanks to the discrete mechanical and swelling properties of each layer and the cohesive/gradual nature of the interface, the resulting bilayered films are able to self-roll in water in less than 30 seconds depending on the nature of the hydrophilic layer and on the shape of the sample. The cytocompatibility and degradability of the materials are demonstrated and confirm the potential of such self-rolling resorbable biomaterials in the field of temporary medical devices.
Evaluation of a biodegradable PLA–PEG–PLA internal biliary stent for liver transplantation: in vitro degradation and mechanical properties
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J. Biomed. Mater. Res. 1-10, (2020)
Girard E., Chagnon G., Moreau-Gaudry A., Letoublon C., Favier D., Dejean S., Trilling B., Nottelet B.
ABSTRACT
Internal biliary stenting during biliary reconstruction in liver transplantation decrease anastomotic biliary complications. Implantation of a resorbable internal biliary stent (RIBS) is interesting since it would avoid an ablation gesture. The objective of present work was to evaluate adequacy of selected PLA-b-PEG-b-PLA copolymers for RIBS aimed to secure biliary anastomose during healing and prevent complications, such as bile leak and stricture. The kinetics of degradation and mechanical properties of a RIBS prototype were evaluated with respect to the main bile duct stenting requirements in liver transplantation. For this purpose, RIBS degradation under biliary mimicking solution versus standard phosphate buffer control solution was discussed. Morphological changes, mass loss, water uptake, molecular weight, permeability, pH variations, and mechanical properties were examined over time. The permeability and mechanical properties were evaluated under simulated biliary conditions to explore the usefulness of a PLA-b-PEG-b-PLA RIBS to secure biliary anastomosis. Results showed no pH influence on the kinetics of degradation, with degradable RIBS remaining impermeable for at least 8 weeks, and keeping its mechanical properties for 10 weeks. Complete degradation is reached at 6 months. PLA-b-PEG-b-PLA RIBS have the required in vitro degradation characteristics to secure biliary anastomosis in liver transplantation and envision in vivo applications
Smart/active surfaces
Antibacterial and antifouling surfaces
About the project:
Contact:
Students:
–
Collaborations:
Prof. Lavigne (CHU Nîmes), Prof. Cavallaro (University of Palermo), Dr. Antonio Stocco (L2C, UMR5221), Dr. Moriarty, Dr. Eglin, Dr. Guillaume (AO Research Institute, Switzerland)
Funding:
AO-CMF grant, Campus France, Post-doctoral program UM, MENRT grant (ED 459)
Dual-crosslinked degradable elastomeric networks with self-healing properties: bringing multi(catechol) star block copolymers into play
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ACS Appl. Mater. Interfaces 15, 2077-2091 (2023)
Mathilde Grosjean, Louis Gangolphe, Stéphane Dejean, Sylvie Hunger, Audrey Bethry, Frédéric Bossard, Xavier Garric, Benjamin Nottelet
ABSTRACT
In the biomedical field, degradable chemically crosslinked elastomers are interesting materials for tissue engineering applications since they present rubber-like mechanical properties matching with those of soft tissues and are able to preserve their 3D structure over degradation. Their use in biomedical applications requires surgical handling and implantation that can be source of accidental damages responsible for loss of properties. Therefore, their inability to be healed after damage or breaking can be a major drawback. In this work, biodegradable dual-crosslinked networks that exhibit fast and efficient self-healing properties at 37 °C are designed. Self-healable dual-crosslinked (chemically and physically) elastomeric networks are prepared from two methods. The first approach is based on the mix of hydrophobic PEG-PLA star-shaped copolymers functionalized either with catechol or methacrylate moieties. In the second approach, hydrophobic bifunctional PEG-PLA star-shaped copolymers with both catechol and methacrylate on their structure are used. In the two systems the supramolecular network is responsible for the self-healing properties thanks to the dynamic dissociation/re-association of the numerous hydrogen bonds between the catechol groups, whereas the covalent network ensures mechanical properties similar to pure methacrylate networks. The self-healable materials display mechanical properties that are compatible with soft tissues and exhibit linear degradation because of the chemical crosslinks. The performances of networks from mix copolymers vs. bifunctional copolymers are compared and demonstrate the superiority of the later. The biocompatibility of the materials is also demonstrated and confirm the potential of these degradable self-healable elastomeric networks to be used for the design of temporary medical devices.
Degradable Bioadhesives Based on Star PEG–PLA Hydrogels for Soft Tissue Applications
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Biomacromolecules XX, XX (2022)
Mathilde Grosjean, Edouard Girard, Audrey Bethry, Grégory Chagnon, Xavier Garric, Benjamin Nottelet
ABSTRACT
Tissue adhesives are interesting materials for wound treatment as they present numerous advantages compared to traditional methods of wound closure such as suturing and stapling. Nowadays, fibrin and cyanoacrylate glues are the most widespread commercial biomedical adhesives, but these systems display some drawbacks. In this study, degradable bioadhesives based on PEG–PLA star-shaped hydrogels are designed. Acrylate, methacrylate, and catechol functional copolymers are synthesized and used to design various bioadhesive hydrogels. Various types of mechanisms responsible for adhesion are investigated (physical entanglement and interlocking, physical interactions, chemical bonds), and the adhesive properties of the different systems are first studied on a gelatin model and compared to fibrin and cyanoacrylate references. Hydrogels based on acrylate and methacrylate reached adhesion strength close to cyanoacrylate (332 kPa) with values of 343 and 293 kPa, respectively, whereas catechol systems displayed higher values (11 and 19 kPa) compared to fibrin glue (7 kPa). Bioadhesives were then tested on mouse skin and human cadaveric colonic tissue. The results on mouse skin confirmed the potential of acrylate and methacrylate gels with adhesion strength close to commercial glues (15–30 kPa), whereas none of the systems led to high levels of adhesion on the colon. These data confirm that we designed a family of degradable bioadhesives with adhesion strength in the range of commercial glues. The low level of cytotoxicity of these materials is also demonstrated and confirm the potential of these hydrogels to be used as surgical adhesives.
Polyester-polydopamine copolymers for intravitreal drug delivery: role of polydopamine drug-binding properties on extending drug release
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Biomacromolecules 23, 4388-4400, (2022)
Floriane Bahuon, Vincent Darcos, Sulabh Patel, Zana Marin, Jean Coudane, Grégoire Schwach, and Benjamin Nottelet
ABSTRACT
This work reports on a novel polyester copolymer containing poly(dopamine), a synthetic analogue of natural melanin, evaluated in sustained-release drug delivery system for ocular intravitreal administration of drugs. More specifically, a graft copolymer of poly(ε-caprolactone)-graft-poly(dopamine) (PCL-g-PDA) has been synthesized, and was shown to further extend the drug release benefits of state-of-the-art biodegradable intravitreal implants made of poly(lactide) and poly(lactide-co-glycolide). The innovative biomaterial combines the documented drug-binding properties of melanin naturally present in the eye, with the established ocular tolerability and biodegradation of polyester implants. The PCL-g-PDA copolymer was obtained by a two-step modification of PCL with a final PDA content around 2-3 wt.%, and was fully characterised by SEC, NMR, and DOSY NMR. The thermoplastic nature of PCL-g-PDA allowed its simple processing by hot-melt compression moulding to prepare small implants. The properties of unmodified PCL and PCL-g-PDA implants were studied and compared in terms of thermal properties (DSC), thermal stability (TGA), degradability and in vitro cytotoxicity. PCL and PCL-g-PDA implants exhibited similar degradation properties in vitro and were both stable under physiological conditions over 110 days. Likewise, both materials were non-cytotoxic towards L929 and ARPE-19 cells. The drug-loading and in vitro release properties of the new materials were investigated with dexamethasone (DEX) and ciprofloxacin hydrochloride (CIP) as representative drugs featuring low and high melanin binding affinities, respectively. In comparison to unmodified PCL, PCL-g-PDA implants showed significant extension of drug release most likely because of specific drug-catechol interaction with the PDA moieties of the copolymer. The present study confirms the advantages of designing PDA-containing polyesters as a class of biodegradable and biocompatible thermoplastics that can modulate and remarkably extend drug release kinetics thanks to their unique drug binding properties, especially, but not limited to, for ocular applications.
Creation of a Stable Nanofibrillar Scaffold Composed of Star-Shaped PLA Network Using Sol-Gel Process during Electrospinning
Karima Belabbes, Coline Pinese *, Christopher Yusef Leon-Valdivieso, Audrey Bethry, Xavier Garric
ABSTRACT
PLA nanofibers are of great interest in tissue engineering due to their biocompatibility and morphology; moreover, their physical properties can be tailored for long-lasting applications. One of the common and efficient methods to improve polymer properties and slow down their degradation is sol-gel covalent crosslinking. However, this method usually results in the formation of gels or films, which undervalues the advantages of nanofibers. Here, we describe a dual process sol-gel/electrospinning to improve the mechanical properties and stabilize the degradation of PLA scaffolds. For this purpose, we synthesized star-shaped PLAs and functionalized them with triethoxysilylpropyl groups (StarPLA-PTES) to covalently react during nanofibers formation. To achieve this, we evaluated the use of (1) a polymer diluent and (2) different molecular weights of StarPLA on electrospinnability, StarPLA-PTES condensation time and crosslinking efficiency. Our results show that the diluent allowed the fiber formation and reduced the condensation time, while the addition of low-molecular-weight StarPLA-PTES improved the crosslinking degree, resulting in stable matrices even after 6 months of degradation. Additionally, these materials showed biocompatibility and allowed the proliferation of fibroblasts. Overall, these results open the door to the fabrication of scaffolds with enhanced stability and prospective long-term applications
Advanced macromolecular chemistry and architectures:
Functional aliphatic polyesters
About the project:
This project aims at exploring various chemical strategies towards (multi)functional polyesters and evaluate their potential in the frame of biomedical applications.
Contact:
Students:
–
Floriane Bahuon
Collaborations:
Dr Lacroix-Desmazes (IAM, ICGM UMR 5253), Roche
Funding:
–
Dual-crosslinked degradable elastomeric networks with self-healing properties: bringing multi(catechol) star block copolymers into play
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ACS Appl. Mater. Interfaces 15, 2077-2091 (2023)
Mathilde Grosjean, Louis Gangolphe, Stéphane Dejean, Sylvie Hunger, Audrey Bethry, Frédéric Bossard, Xavier Garric, Benjamin Nottelet
ABSTRACT
In the biomedical field, degradable chemically crosslinked elastomers are interesting materials for tissue engineering applications since they present rubber-like mechanical properties matching with those of soft tissues and are able to preserve their 3D structure over degradation. Their use in biomedical applications requires surgical handling and implantation that can be source of accidental damages responsible for loss of properties. Therefore, their inability to be healed after damage or breaking can be a major drawback. In this work, biodegradable dual-crosslinked networks that exhibit fast and efficient self-healing properties at 37 °C are designed. Self-healable dual-crosslinked (chemically and physically) elastomeric networks are prepared from two methods. The first approach is based on the mix of hydrophobic PEG-PLA star-shaped copolymers functionalized either with catechol or methacrylate moieties. In the second approach, hydrophobic bifunctional PEG-PLA star-shaped copolymers with both catechol and methacrylate on their structure are used. In the two systems the supramolecular network is responsible for the self-healing properties thanks to the dynamic dissociation/re-association of the numerous hydrogen bonds between the catechol groups, whereas the covalent network ensures mechanical properties similar to pure methacrylate networks. The self-healable materials display mechanical properties that are compatible with soft tissues and exhibit linear degradation because of the chemical crosslinks. The performances of networks from mix copolymers vs. bifunctional copolymers are compared and demonstrate the superiority of the later. The biocompatibility of the materials is also demonstrated and confirm the potential of these degradable self-healable elastomeric networks to be used for the design of temporary medical devices.
Degradable Bioadhesives Based on Star PEG–PLA Hydrogels for Soft Tissue Applications
This is custom heading element
Biomacromolecules XX, XX (2022)
Mathilde Grosjean, Edouard Girard, Audrey Bethry, Grégory Chagnon, Xavier Garric, Benjamin Nottelet
ABSTRACT
Tissue adhesives are interesting materials for wound treatment as they present numerous advantages compared to traditional methods of wound closure such as suturing and stapling. Nowadays, fibrin and cyanoacrylate glues are the most widespread commercial biomedical adhesives, but these systems display some drawbacks. In this study, degradable bioadhesives based on PEG–PLA star-shaped hydrogels are designed. Acrylate, methacrylate, and catechol functional copolymers are synthesized and used to design various bioadhesive hydrogels. Various types of mechanisms responsible for adhesion are investigated (physical entanglement and interlocking, physical interactions, chemical bonds), and the adhesive properties of the different systems are first studied on a gelatin model and compared to fibrin and cyanoacrylate references. Hydrogels based on acrylate and methacrylate reached adhesion strength close to cyanoacrylate (332 kPa) with values of 343 and 293 kPa, respectively, whereas catechol systems displayed higher values (11 and 19 kPa) compared to fibrin glue (7 kPa). Bioadhesives were then tested on mouse skin and human cadaveric colonic tissue. The results on mouse skin confirmed the potential of acrylate and methacrylate gels with adhesion strength close to commercial glues (15–30 kPa), whereas none of the systems led to high levels of adhesion on the colon. These data confirm that we designed a family of degradable bioadhesives with adhesion strength in the range of commercial glues. The low level of cytotoxicity of these materials is also demonstrated and confirm the potential of these hydrogels to be used as surgical adhesives.
Polyester-polydopamine copolymers for intravitreal drug delivery: role of polydopamine drug-binding properties on extending drug release
This is custom heading element
Biomacromolecules 23, 4388-4400, (2022)
Floriane Bahuon, Vincent Darcos, Sulabh Patel, Zana Marin, Jean Coudane, Grégoire Schwach, and Benjamin Nottelet
ABSTRACT
This work reports on a novel polyester copolymer containing poly(dopamine), a synthetic analogue of natural melanin, evaluated in sustained-release drug delivery system for ocular intravitreal administration of drugs. More specifically, a graft copolymer of poly(ε-caprolactone)-graft-poly(dopamine) (PCL-g-PDA) has been synthesized, and was shown to further extend the drug release benefits of state-of-the-art biodegradable intravitreal implants made of poly(lactide) and poly(lactide-co-glycolide). The innovative biomaterial combines the documented drug-binding properties of melanin naturally present in the eye, with the established ocular tolerability and biodegradation of polyester implants. The PCL-g-PDA copolymer was obtained by a two-step modification of PCL with a final PDA content around 2-3 wt.%, and was fully characterised by SEC, NMR, and DOSY NMR. The thermoplastic nature of PCL-g-PDA allowed its simple processing by hot-melt compression moulding to prepare small implants. The properties of unmodified PCL and PCL-g-PDA implants were studied and compared in terms of thermal properties (DSC), thermal stability (TGA), degradability and in vitro cytotoxicity. PCL and PCL-g-PDA implants exhibited similar degradation properties in vitro and were both stable under physiological conditions over 110 days. Likewise, both materials were non-cytotoxic towards L929 and ARPE-19 cells. The drug-loading and in vitro release properties of the new materials were investigated with dexamethasone (DEX) and ciprofloxacin hydrochloride (CIP) as representative drugs featuring low and high melanin binding affinities, respectively. In comparison to unmodified PCL, PCL-g-PDA implants showed significant extension of drug release most likely because of specific drug-catechol interaction with the PDA moieties of the copolymer. The present study confirms the advantages of designing PDA-containing polyesters as a class of biodegradable and biocompatible thermoplastics that can modulate and remarkably extend drug release kinetics thanks to their unique drug binding properties, especially, but not limited to, for ocular applications.
Creation of a Stable Nanofibrillar Scaffold Composed of Star-Shaped PLA Network Using Sol-Gel Process during Electrospinning
Karima Belabbes, Coline Pinese *, Christopher Yusef Leon-Valdivieso, Audrey Bethry, Xavier Garric
ABSTRACT
PLA nanofibers are of great interest in tissue engineering due to their biocompatibility and morphology; moreover, their physical properties can be tailored for long-lasting applications. One of the common and efficient methods to improve polymer properties and slow down their degradation is sol-gel covalent crosslinking. However, this method usually results in the formation of gels or films, which undervalues the advantages of nanofibers. Here, we describe a dual process sol-gel/electrospinning to improve the mechanical properties and stabilize the degradation of PLA scaffolds. For this purpose, we synthesized star-shaped PLAs and functionalized them with triethoxysilylpropyl groups (StarPLA-PTES) to covalently react during nanofibers formation. To achieve this, we evaluated the use of (1) a polymer diluent and (2) different molecular weights of StarPLA on electrospinnability, StarPLA-PTES condensation time and crosslinking efficiency. Our results show that the diluent allowed the fiber formation and reduced the condensation time, while the addition of low-molecular-weight StarPLA-PTES improved the crosslinking degree, resulting in stable matrices even after 6 months of degradation. Additionally, these materials showed biocompatibility and allowed the proliferation of fibroblasts. Overall, these results open the door to the fabrication of scaffolds with enhanced stability and prospective long-term applications
Advanced and well-defined macromolecular architectures
About the project:
Within this project we take advantage of the opportunities offered by advanced macromolecular chemistry to design various macromolecular topologies and evaluate their potential compared to classical linear (co)polymers.
Contact:
Students:
Collaborations:
Dr. Etrych, Dr. Koziolova, Dr. Kostka (Institute of Macromolecular Chemistry, Czech Republic)
Funding:
Campus France
Graft Copolymers with Tunable Amphiphilicity tailored for Efficient Dual Drug Delivery via Encapsulation and pH-sensitive Drug Conjugation
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Polymer Chemistry 11, 4438–4453 (2020)
Bláhová M., Randárová E., Konefał R., Nottelet B., Etrych T.
ABSTRACT
Polymer-based drug delivery systems may significantly improve cancer therapy. We developed amphiphilic poly(e-caprolactone)-graft-(poly-N-(2-hydroxypropyl) methacrylamide) copolymers (PCL-graft-pHPMA) with tunable amphiphilicity intended for efficient dual delivery via simultaneous encapsulation of hydrophobic drug, Bcl-2 inhibitor ABT-199, and pH-sensitive conjugation of other chemotherapeutics, doxorubicin, to desired sites, e.g. tumors. Using controlled RAFT polymerization and click chemistry well-defined PCL-graft-pHPMA of diverse Mw and physical properties were prepared. By simple dissolution they self-assembled into highly stable micelles with Dh ≈ 25 nm and low critical micelle concentration (around 5 μg mL-1). The total drug payload reached 17 wt % while maintaining system solubility. The micelles exhibited long-term stability in buffers, while they were cleaved in the presence of lipase, thus proving degradation and drug release after uptake to lysosomes of cancer cells with minimal drug leakage during blood circulation. PCL-graft-pHPMA micelles may serve as a long-circulating drug depo for effective dual therapy of diverse malignancies.
N-(2-Hydroxypropyl)methacrylamide-Based Linear, Diblock, and Starlike Polymer Drug Carriers: Advanced Process for Their Simple Production
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Biomacromolecules 19, 4003–4013 (2018)
Koziolova, E., Kostka, L., Kotrchova, L., Subr, V., Konefal, R., Nottelet, B. & Etrych, T.
ABSTRACT
We developed a new simplified method for the synthesis of well-defined linear, diblock, or starlike N-(2-hydroxypropyl)methacrylamide (HPMA)-based polymer drug carriers using controlled reversible addition–fragmentation chain transfer polymerization. The prepared monodispersed polymers are after the drug attachment intended for enhanced anticancer therapy. This new approach significantly reduces the number of required synthetic steps and minimizes the consumption of organic solvents during the synthesis. As a result, highly defined linear, diblock, and starlike copolymers designed for pH-triggered drug activation/release in tumor tissue were formed in sufficient amounts for further physicochemical and biological studies. Within the synthesis, we also developed a new procedure for the selective deprotection of tert-butoxycarbonyl hydrazide and amine groups on hydrophilic HPMA copolymers, including the one-pot removal of polymer end groups. We studied and described in detail the kinetics and efficacy of the deprotection reaction. We believe the simplified synthetic approach facilitates the preparation of polymer conjugates bound by the pH-sensitive hydrazone bond and their application in tumor treatment.
PCL-PEG graft copolymers with tunable amphiphilicity as efficient drug delivery systems
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Mat. Chem. B 4, 6228–6239 (2016)
Al Samad, A., Bethry, A., Koziolova, E., Netopilik, M., Etrych, T., Bakkour, Y., Coudane, J., El Omar, F. & Nottelet, B.
ABSTRACT
The development of flexible drug delivery systems that can be tuned as a function of the drug to be delivered and of the target disease is crucial in modern medicine. For this aim, novel amphiphilic poly(ε-caprolactone)-g-poly(ethylene glycol) (PCL-g-PEG) copolymers with well-controlled design were synthesized by thiol–yne photochemistry. The grafting density and the copolymer amphiphilicity were easily controlled via the reaction parameters: concentration, reaction time, PEG length and the molar ratio between PCL and PEG or the photoinitiator in the reaction mixture. The self-assembling behavior of the copolymers was studied and a correlation between the composition of PCL-g-PEG and the nanoaggregate diameter sizes (28 to 73 nm) and critical aggregation concentrations (1.1 to 4.3 mg L−1) was found. The influence of copolymer amphiphilicity on the drug loading was evaluated with various drugs including anticancer drugs (paclitaxel, ABT-199), drugs to overcome multidrug resistance in cancer cells (curcumin, elacridar), an anti-inflammatory drug (dexamethasone) and an antibacterial drug (clofazimine). Finally, the influence of amphiphilicity on curcumin release and toxicity towards MCF-7 cancer cell lines was studied. The impact of the grafting density, PEG length and the overall EG/CL ratio is discussed in detail. Curcumin loaded PCL-g-PEG with lower EG/CL ratios and shorter PEG chains showed higher toxicity compared to their more hydrophilic counterparts.
From nanospheres to micelles: simple control of PCL-g-PEG copolymers’ amphiphilicity through thiol-yne photografting
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Polym. Chem. 6, 5093–5102 (2015)
Al Samad, A., Bakkour, Y., Fanny, C., El Omar, F., Coudane, J. & Nottelet, B
ABSTRACT
A simple method for the synthesis of a family of poly(ɛ-caprolactone)-g-polyethylene glycol (PCL-g-PEG) copolymers of controlled amphiphilicity and their use to generate nanospheres or micelles are reported. PCL-g-PEG with various compositions are prepared from a single strategy relying on a combination of post-polymerization modification and subsequent thiol-yne photografting. Alkyne-functional PCL (PCL-yne) are first obtained by anionic activation and reaction with propargyl bromide to yield PCL-yne with 8% alkyne groups. PEG-thiol is then reacted on PCL-yne under UV activation to yield the targeted graft copolymer by thiol-yne photoaddition. The advantage of the approach is that control over the composition is easily achieved yielding to amphiphilic graft copolymers with ethylene glycol/ caprolactone (EG/CL) ratios ranging from 0.1 to 1.3. Starting from this single strategy, it was therefore possible to obtain nanospheres (DH~55 nm) or micelles (DH~30 nm) by copolymers self-assembly depending on the ratio EG/CL. The potential of the PCL-g-PEG micelles as drug carrier was finally evaluated with curcumin that was efficiently encapsulated, protected and released over 80 days. Interestingly it was found that drug encapsulation efficiency and drug loading were higher for PCL-g-PEG copolymers compared to block PCL-b-PEG.