Decreased fibroblast cell density on chemically degraded poly-lactic-co-glycolic acid, polyurethane, and polycaprolactone

Select prolonged functions of fibroblasts leading to extensive fibrous tissue encapsulation can be detrimental to numerous implant applications, including materials designed for the bladder, vasculature, and bone. Specifically, overextended functions of fibroblasts at the tissue–implant interface for orthopedic applications lead to callus formation, fibrous encapsulation events, and ultimately soft (not desirable hard-bony) tissue juxtaposition. Such events result in insufficient regeneration of bone and compromise the overall success of the implant. The objective of the present in vitro study was to determine, for the first time, fibroblast densities on NaOH-treated poly-lactic-co-glycolic acid co-polymers (PLGA), HNO3-treated polyurethane (PU), and NaOH-treated polycaprolactone (PCL). Previous studies have demonstrated increased bladder, vascular, and bone cell densities on chemically treated compared to unaltered PLGA, PU, and PCL films. Results of this study provided evidence of decreased fibroblast numbers on chemically treated PLGA, PU, and PCL after time periods of up to 5 days. Examination of these substrates revealed that all chemically modified polymers possessed a high degree of nanometer surface roughness compared to their respective unaltered polymers. In contrast, other material properties (such as chemistry and wettability) were different when comparing chemically treated PLGA, PU, and PCL films. Since fibroblasts are anchorage-dependent cells whose adhesion is a critical prerequisite to the prolonged, extensive formation of a fibrous-tissue containing extracellular matrix, the present in vitro results of decreased fibroblast densities on chemically degraded PLGA, PU, and PCL suggest that these materials may be suitable materials for numerous tissue-engineering applications and, thus, deserve further investigation.