Synthesis and characterization of biodegradable fibrin based biomaterial for wound repair

Abstract

Event Abstract Back to Event Synthesis and characterization of biodegradable fibrin based biomaterial for wound repair Marie Deneufchâtel1, 2, Véronique Larreta-Garde2 and Odile Fichet1 1 University of Cergy-Pontoise, Laboratoire de Physicochimie des Polymères (LPPI), France 2 University of Cergy-Pontoise, Equipe de Recherche sur les Relations Matrice Extracellulaire Cellules (ERRMECe), France Introduction: Fibrin gels find widespread applications in tissue engineering such as glues, microbeads and scaffold for the reconstruction of various tissues. However, it cannot be handled at physiological concentration. To improve its mechanical properties, it has been combined with a synthetic PolyEthylene Oxide (PEO), copolymerized with a modified protein (Serum Albumin, SAm) to remain biodegradable, inside Interpenetrating Polymer Network (IPN) architecture[1]-[3]. The synthesis and characterization of this new series of self-supported materials based on fibrin is described. Experimental: The SA modification with methacrylate was performed as previously described[3]. The synthetic soluble fractions were quantified by Soxhlet Extraction with CH2Cl2 for 3 days. The protein soluble part was extracted with water and quantified by a Bradford assay. Mechanical properties were evaluated by rheology. Cytotoxicity was assessed using a Live/Dead Assay (Invitrogen). The cells and ECM morphology were observed as previously described[2]. Results and Discussion: PEO-SA/Fb IPN were synthesized by mixing aqueous solutions of all reactants in the appropriate proportions and the mixture was placed at 37°C under UV (365 nm) for 1h. Fibrin (Fb) gel at the physiological concentration (0.5 mg/mL) was synthesized by hydrolysis of fibrinogen by thrombin. The PEO-SA conetwork (total concentration = 100 mg/mL) was synthesized by free radical copolymerization of Polyethylene Oxide dimethacrylate (PEGDM) and SAm. The gel times were of 10 min or less. The obtained materials are homogeneous and transparent. Both networks inside IPNs were correctly synthesized because the ratios of unbound components were lower than 5% for both proteins and PEGDM. These materials are self-supported and can easily be handled as evidenced by their storage moduli G’ values of more than 2 kPa whatever the IPN composition. Biodegradability has been assessed by immersing the materials in a thermolysin enzymatic solution. According to their composition, they are either totally solubilized or fragmented after a couple days. Their degradation kinetic was studied by quantifying the proteins released from the IPNs (OD280) and by assessing the loss of mechanical properties (rheology). Finally, IPN biocompatibility has been assessed by cultivating fibroblasts on the material top for up to 5 weeks. The viability remains higher than 90%, and extracellular matrix molecules (fibronectin, collagen) were produced (figure 1). These IPN conetwork work as a scaffold for wound repair that is slowly degraded while the cells colonize it. A new derm will then be synthesized as the cells secrete the macromolecules of the extracellular matrix. Conclusions: Innovative biomaterials based on a fibrin gel associated with a conetwork of PEO and biodegradable Serum Albumin were synthesized. Fibrin gel becomes then easily handled and remains biodegradable. Their degradation rate can be controlled by the SA proportion. These new IPNs are biocompatible and allow the cells to produce an extracellular matrix. Direction Générale de l'Armenent (DGA); Agence Nationale pour la Recherche (ANR-13-TECS-0014, FibriDerm project); Région Ile-de-France, SESAME project (Comicer project)