ABSTRACT
INTRODUCTION: Bioresorbable polymers are often used in medical procedures. Since they are biocompatible, this class of materials is a viable alternative for cases in which tissue regeneration is strongly compromised. Bioresorbable synthetic polymers may be used as membranes to support and guide cell growth through the process of tissue repair. OBJECTIVE: To assess the efficiency of a porous bioresorbable membrane Poly (L-co-DL lactic acid)-co-trimethylene carbonate, PL-co-DLA-co-TMC, as a dermal substitute associated with partial skin graft in rats. METHODS: A 1.5×1.5 cm defect was created on the backs of 40 Wistar rats. The rats were divided into a control group, in which the defects were filled with partial skin graft, and a treated group, in which a membrane associated with the graft was implemented. The animals were sacrificed 7 days or 60 days after the procedure and the results were evaluated by macroscopic and microscopic analysis. RESULTS: The polymer was biocompatible and allowed better regeneration of the dermis with less shrinkage, unlike what occurs in second intention healing. Compared to the control group, the treated group showed a thicker and wider dermis with the presence of skin appendages, suggesting partial graft integration and better healing. The skin graft acted as a biological protection of the wound. CONCLUSION: The study material was shown to act as a biocompatible dermal substitute and promoted less scarring of the dermis. Further studies should be conducted to improve the methodology of the surgical procedure.
ABSTRACT
The inability of the avascular region of the meniscus to regenerate has led to the use of tissue engineering to treat meniscal injuries. The aim of this study was to evaluate the ability of fibrochondrocytes preseeded on PLDLA/PCL-T [poly(L-co-D,L-lactic acid)/poly(caprolactone-triol)] scaffolds to stimulate regeneration of the whole meniscus. Porous PLDLA/PCL-T (90/10) scaffolds were obtained by solvent casting and particulate leaching. Compressive modulus of 9.5±1.0 MPa and maximum stress of 4.7±0.9 MPa were evaluated. Fibrochondrocytes from rabbit menisci were isolated, seeded directly on the scaffolds, and cultured for 21 days. New Zealand rabbits underwent total meniscectomy, after which implants consisting of cell-free scaffolds or cell-seeded scaffolds were introduced into the medial knee meniscus; the negative control group consisted of rabbits that received no implant. Macroscopic and histological evaluations of the neomeniscus were performed 12 and 24 weeks after implantation. The polymer scaffold implants adapted well to surrounding tissues, without apparent rejection, infection, or chronic inflammatory response. Fibrocartilaginous tissue with mature collagen fibers was observed predominantly in implants with seeded scaffolds compared to cell-free implants after 24 weeks. Similar results were not observed in the control group. Articular cartilage was preserved in the polymeric implants and showed higher chondrocyte cell number than the control group. These findings show that the PLDLA/PCL-T 90/10 scaffold has potential for orthopedic applications since this material allowed the formation of fibrocartilaginous tissue, a structure of crucial importance for repairing injuries to joints, including replacement of the meniscus and the protection of articular cartilage from degeneration.
