Fumarate Copolymer ? Chitosan crosslinked scaffold directed to osteochondral tissue engineering

M. L. LASTRA; M.S. CORTIZO; M.S. MOLINUEVO

Foz do Iguaçu

Congreso; 9° Congresso Latino-Americano de Orgãos Artificiais e Biomateriais; 2016

Tissue engineering aims to recreate the native environment to promote the appropriate cell behavior for tissue regeneration. Osteochondral lesions are difficult to restore without the aid of a scaffold because of the complexity of this tissue. One necessary condition for the use of these materials is the degradation rate that must be in line with the time needed for tissue repair, water absorption capacity and a needed low toxicity.We have previously prepared a scaffold by cross-linking fumarate copolymer and chitosan and we have demonstrated that this scaffold allowed growth and differentiation of osteoprogenitor cells. In this work we extended our study evaluating the degradation rate, swelling properties and the possible inflammatory response (cytotoxicity) of this cross-linked biomaterial. Degradation rate was evaluated after 45 days of incubation in phosphate buffered saline with or without lipase enzyme (25 IU/ml) at 37°C in a humidifiedatmosphere containing 5% CO2. We found an adequate rate of degradation for application in bone tissue engineering (10% at final time point on both conditions). Swelling studies showed that our scaffold present properties compatible with a hydrogel (303%). Cytotoxicity was evaluated using a murine macrophage cell line RAW264.7 in culture. Cells were grown on the scaffold during 7 days. After that cell morphology, and the production of pro-inflammatory cytokine nitric oxide (NO) and interleukin 1 (IL-1) was evaluated. We found that cell morphology was not affected by the presence of the scaffold, as well as the production of the inflammatory cytokines markers was not affected compared to control condition (standard tissue culture dishes). In conclusion, our results suggested that our crosslinked fumarate/chitosan based scaffold would be useful in the regeneration of osteochondral tissue engineering since it is able to incorporate water, degrades slowly with time and presented low cytotoxicity.