Nanostructured fumarate copolymer/chitosan based scaffold designed for bone tissue engineering

M. LAURA LASTRA; IWONA BLASZCZYK-LEZAK; M. SILVINA MOLINUEVO; M. SUSANA CORTIZO; CARMEN MIJANGOS

Mar del Plata

Congreso; LXI Reunión anual de la sociedad argentina de investigación clínica (SAIC) y VII Reunión anual de la sociedad argentina de nanomedicina (NANOMEDAR); 2016

Nanostructured polymers (NP) have recently emerged as promising candidates to efficiently achieve tissue reparation. NP has been proposed to efficiently mimic the natural extracellular matrix (ECM) and thus promote tissue healing. On the other hand, successful tissue regeneration requires scaffolds made of materials with good biocompatibility and low cytotoxicity. It is well accepted that natural polymers or its blends with synthetic polymers present better biocompatibility properties than synthetic polymers alone. Thus we hypothesizes that nanostructured matrices based on natural polymers will improve stem cells (BMPC) development and osteogenic maturation. To prove our hypothesis we designed nanostructured matrices based on fumaric copolymer and chitosan (diisopropyl fumarate-vinyl acetate copolymer chitosan crosslinked with borax, PFVH-CHI) using an anodized aluminum oxide template of two different pore diameter (170 nm (SN170) and 300 nm (SN300)). Characterization of the polymer was performed by ATR-FTIR, DSC and TGA. The polymer alone or crosslinked were stable at the infiltration conditions (melting the precursor film by wetting method). The nanostructured PFVH-CHI was studied by confocal Raman spectroscopy and SEM. BMPC were used for biocompatibility study (MTT assay) and osteogenic studies (Collagen (Col1) and Mineral production). Our studies show that BMPC adhere better on SN170 than on SN300. However, after 24h BMPC proliferate best on SN300. Osteogenic development showed that BMPC produced low levels of Col1, but it was able to mineralize the ECM. But there were no differences between SN170 and SN300. Additionally the toxicity of the biomaterial was evaluated using a model of macrophages in culture. We found that the nanostructuration of the matrix caused low cytotoxicity as it was measured by IL1, TNFa and NO production. Altogether our results suggest that nanostructuration of the polymers would improve osteogenic BMPC development and maturation.