ABSTRACT
Accordion nerve conduit of poly(lactide-co-glycolide-co-ε-caprolactone) with perforations was developed by excimer laser processing. We evaluated its in vivo function for nerve repairing and discussed the influence of pore size and density. It was found that perforations help inner nerve regeneration remarkably, which effect is unrelated to pore size or density, and is not parallel with revascularization increment. Inducing of permeability only to allow substance exchange but not vessel ingrowth could facilitate nerve regeneration too. Perforating micropores with the size of 100 µm and the density of 25/cm provides permeability and vessel ingrowth both, therefore promotes the axon extension the best, larger, and more pores do not advance axon regeneration more.
Subject(s)
Absorbable Implants , Guided Tissue Regeneration/instrumentation , Nerve Regeneration , Polyesters , Prostheses and Implants , Tissue Scaffolds , Animals , Biocompatible Materials , Implants, Experimental , Lasers , Male , Microscopy, Electron, Scanning , Neovascularization, Physiologic , Porosity , Rats , Rats, Sprague-Dawley , Sciatic Nerve/blood supply , Sciatic Nerve/physiology , Sciatic Nerve/surgery , Sciatic Nerve/ultrastructure , Wound HealingABSTRACT
In this study, we investigated the use of perforated sheet platforms to improve the attachment of percutaneous devices to surrounding tissues. The model platform was created by a poly(methyl methacrylate) (PMMA) sheet with a matrix of 200-microm diameter perforations covering the groove (width, 3 mm; depth, 0.5 mm) prepared on the PMMA cylinder (diameter, 10 mm; length, 6 mm). Velour cuffs from peritoneal dialysis catheters were used as controls. Specimens were implanted percutaneously in rats, harvested with the surrounding tissues at 4 weeks after surgery, and subjected to mechanical tests and histological observations. The attachment strength of the experimental specimens to tissue was 138.4 +/- 123.6 kPa (n = 5, mean SD); although it was greater than the 67.23 +/- 45.78 kPa (n = 5) of the controls, no statistical significance was found. Histological observations of the experimental specimens revealed the collagen fibers originating from the surrounding tissues, passing through the perforations of the sheet, merging into the collagen fibers running behind the sheet, and thus anchoring the tissues to the device. In contrast, such anchoring of collagen fibers was not evident in the controls. These results suggest that the proposed perforated sheet structures are effective for soft tissue attachment.
