Chitosan/poly(DL,lactide-co-glycolide) scaffolds for tissue engineering

Evaluation of in vitro bioactivity and in vitro biocompatibility of Polycaprolactone/Hyaluronic acid/Multiwalled Carbon Nanotubes/Extract from Mimosa tenuiflora composites

BACKGROUND

The development of biomaterial scaffolds and implementation of tissue engineering techniques are necessary. Therefore, Polycaprolactone/Sodium Hyaluronate/Multiwalled Carbon Nanotubes/Extract of Mimosa tenuiflora composites have been produced by a thermally-induced phase separation method.

OBJECTIVE

The objective of this research was to evaluate the in vitro bioactivity and in vitro biocompatibility of the composites.

METHODS

The in vitro bioactivity of the composites was assessed by soaking them in simulated body fluid for 7, 14, 21, and 28 days. The structure and composition of the composites were analyzed using scanning electron microscopy coupled with energy dispersive spectroscopy and Fourier transform infrared spectroscopy. Also, the in vitro biocompatibility of the composites was evaluated by means of alkaline phosphatase activity of the osteoblasts and by measuring the metabolic activity of the cells using MTT assay.

RESULTS

The results show a porous and interconnected morphology with enhanced bioactivity. It was observed that the incorporation of Mimosa tenuiflora in the composites promotes increased viability of osteoblasts in the scaffolds.

CONCLUSIONS

The results show the efficiency of bioactive and biocompatible composites and their potential as candidates for tissue engineering applications.

Biocompatibility and in vivo degradation of chitosan based hydrogels as potential drug carrier

Carboxymethyl chitosan-graft-polylactide (CMCS-PLA) and carboxymethyl chitosan (CMCS) hydrogels were prepared by using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) as crosslinking agent and catalyst at room temperature. The biocompatibility of the hydrogels was evaluated with the aim of assessing their potential as drug carrier. Various aspects of biocompatibility were considered, including MTT assay, agar diffusion test, release of lactate dehydrogenase (LDH), hemolytic test, plasma recalcification time (PRT), and dynamic clotting time. MTT assay showed that the cytotoxicity level of both hydrogels to L-929 cells was 0 or 1. The LDH release of CMCS and CMCS-PLA was 26 and 29%, respectively, which is slightly higher than that of the negative control (21%) and much lower than that of the negative control (87%). The hemolysis ratio of CMCS and CMCS-PLA was 1.4 and 1.7%, respectively, suggesting outstanding anti-hemolysis properties of both materials. The PRT value of CMCS and CMCS-PLA was higher by 77 and 99% than the value of the positive control. All the results revealed that the hydrogels present good cytocompatibility and hemocompatibility in vitro. In vivo degradation and tissue compatibility were evaluated by subcutaneous injection in the dorsal area of rats. CMCS and CMCS-PLA hydrogels were completely degraded and the inflammatory response also completely disappeared around hydrogels after 19 days in vivo. It is thus concluded that hydrogels formed of CMCS and CMCS-PLA with outstanding biocompatibility are promising as potential drug carrier.