In vitro degradation and biocompatibility of poly(l-lactic acid)/chitosan fiber composites

In this study, poly(l-lactic acid) (PLLA) fibers were prepared by the dry-wet-spinning method, while chitosan (CHS) fibers were prepared via the wet-spinning method. The two fibers were blend spun and then fabricated into PLLA/CHS fabrics. In vitro degradation experiments of the fabrics were carried out in a phosphate-buffered solution at 37 °C with a pH of 7.4. Changes in molecular parameters (molecular weights and molecular weight distributions), phase structures (crystallinities), morphologies (fiber surface topologies) of the PLLA fibers, and their macroscopic properties (the fabric weight losses and mechanical strengths) were monitored with degradation times. These results were compared with control samples with no degradation. The hydrolysis mechanism of PLLA/CHS fabrics was analyzed. It was found that the degradation rate of dry-wet-spun PLLA fibers was higher than those of the melt-spun or dry-spun ones. Furthermore, the compatibility between PLLA/CHS fabrics and osteoblast under the in vitro degradation was investigated for the potential application of using the PLLA/CHS fabrics as supporting materials for chest walls and bones. Cell strain hFOB1.19 human SV40-transfected osteoblast and PLLA/CHS mixed fabrics were incubated. The cell morphology at early stages of cultivation was also studied. Excellent adhesion between osteoblast and PLLA/CHS fabrics was observed, indicating good biocompatibility of the fabrics with osteoblast.