Enhanced peripheral nerve regeneration by the combination of a polycaprolactone (PCL) tubular prosthesis and a scaffold of collagen with supramolecular organization

• Grant number: 13/09407-6
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: June 01, 2013
• End date: November 30, 2013
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Principal Investigator: Alexandre Leite Rodrigues de Oliveira
• Grantee: Alexandre Leite Rodrigues de Oliveira
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The purpose of this study was to investigate the influence of implanting collagen with a supramolecular organization on peripheral nerve regeneration, using the sciatic nerve tubulization technique. For this purpose, adult female Sprague Dawley rats were divided into five groups: 1) TP - sciatic nerve repaired with empty polyethylene tubular prothesis (n=10), 2) TPCL - nerve repair with empty polycaprolactone (PCL) tubing (n=8), 3) TPCLF - repair with polycaprolactone (PCL) tubing filled with an implant of collagen with a supramolecular organization (n=10), 4) AG - animals that received a peripheral nerve autograft (n=8), 5) Normal nerves (n=8). The results were assessed by quantification of the regenerated fibers, nerve morphometry and transmission electron microscopy, sixty days after surgery. Immunohistochemistry and polarization microscopy were also used to analyze the regenerated nerve structure and cellular elements. The results showed that the AG group presented a larger number of regenerated axons. However, the TPCL and TPCLF groups presented more compact regenerated fibers with a morphometric profile closer to normal, both at the tube midpoint and 2mm distal to the prosthesis. These findings were reinforced by polarization microscopy, which indicated a better collagen/axons suprastructural organization in the TPCLF derived samples. In addition, the immunohistochemical results obtained using the antibody anti-p75NTR as a Schwann cell reactivity marker, demonstrated that the Schwann cells were more reactive during the regenerative process in the TPCLF group as compared to the TPCL group and the normal sciatic nerve. Altogether, the results of this study indicated that the implant of collagen with a supramolecular organization positively influenced and stimulated the regeneration process through the nerve gap, resulting in the formation of a better morphologically arranged tissue. (AU)