Characterization of chitosan and polycaprolactone membranes designed for wound repair application

Polycaprolactone (PCL) and chitosan (Ch) are nontoxic, biocompatible, and biodegradable polymers of vast interest for wound repair. The aim of this work was to prepare Ch/PCL membranes in different proportions (90:10 and 80:20 w/w) in the presence and absence of the surfactant Pluronic F68 (PF68). The membranes were evaluated regarding morphology, thermal behavior, and viscoelastic properties. Sample swelling and degradation in phosphate-buffered saline (PBS), simulated body fluid (SBF), and fetal bovine serum (FBS) were determined by differential scanning calorimetry (DSC) and dynamical mechanical analysis (DMA), while cell toxicity to L929 and Vero fibroblasts was evaluated using the MTT reduction assay and cell proliferation, by DNA quantification and confocal laser microscopy. After 60 days in SBF, marked Ch matrix loss and advanced degradation of PCL particles were noticed by scanning electron microscopy (SEM). No significant differences in melting temperature (Tm) and enthalpy (DHm) were detected by DSC. However, the surfactant increased the DHm. After 30 days, the membranes obtained in the presence of PF68 had absorbed more blood serum and were more degraded after exposure to simulated blood fluid for 30 days. All membranes had low cytotoxicity, and higher cell proliferation was noticed for samples obtained in the presence of the surfactant. In conclusion, the Ch/PCL membranes showed satisfactory degradability and biocompatibility, which enhances their potential for application in wound repair.The authors thank the PhD student Sofia Caridade (3B's Research Group-Universidade do Minho, Portugal) for her assistance in the DMA analyses. The financial support provided by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq-150984/2009-0) in Brazil is gratefully acknowledged for this work