![]() ![]() Various forms of microscopy, have been employed m the charactertzatton of the ECM analogs. However, structural methodology that has been used to characterize synthetic polymeric networks, including infrared and Raman spectroscopy, rubber elasticity analysis of network structure and Type I collagen/chondromn 6-sulfate, (w/w) Degradation half-life, wk Average pore diameter, pm Pore channel orientationįor the structural analysts of protems. ![]() Being insoluble, the ECM analogs cannot be isolated and characterized structurally using common biochemical techniquesĬoNagen-Glycosaminoglycan Table I Structural On the larger scale, the analogs are highly porous matrices that are characterized in terms of the pore volume fraction, the average pore diameter and the average orientation of pore channel axes. In the former scale, both ECM analogs referred to above are graft copolymers of type I collagen and chondroitin 6-sulfate, which are crosslinked covalently, and can therefore be described as insoluble macromolecular networks. The structure of these biologically active ECM analogs has been characterized on the scale of the nanometer, as well as on the scale of the micrometer. Another ECM analog, similar in structure to the SRT and the NRT, has been shown capable of regenerating the canine knee meniscus (18). The selection of the collagen tube instead of the silicone tube, based on superior regenerative activity, has also been made in the same animal model (17). The structure of the NRT has been determined by selection of the network structure that resulted in maximum regenerative activity in the sciatic nerve model, using a gap of 10 mm (3,16). If the silicone tube is used without an ECM analog, the maximum gap distance that can be bridged by a functional peripheral nerve in this animal model is only 10 mm (15). In this model, the highly porous ECM analog is used to till the lumen of a tube, made either of silicone (nondegradable) or collagen (biodegradable) the nerve stumps are inserted into the tube and are prevented from being displaced further by two sutures at each stump (Fig. NRT, ensheathed by an implantation tube, as it would be implanted in the peripheral nerve wound model. SRT as it would be implanted in the skin wound modelįig. Me&me, Vol 18 Tmsue Engmeenng Methods and and M L Yarmush 0 Humana Press Inc, Totowa,įig. The latter has no blologlcal actlvlty, but serves as a temporary dressing that protects the proximal layer from dehydration and bacterial invasion, and also converts the bdayer mto a mechamcally competent sheet, capable of being handled conveniently and sutured on the patlent’s tissues Another ECM analog, referred to as the nerve regeneration template (NRT), has induced regeneration of a functional peripheral nerve across a 15-mm gap From The SRT 1s currently used as a dermal regeneration treatment for patients who have sustained deep burns or deep mechanical trauma, mcludmg trauma from elective surgery, and who would otherwise have been treated with autografts (10) In the clinical settmg or m animal models, the SRT 1s apphed on wounds as a bllayer graft the proximal layer 1s the highly porous ECM analog and the distal layer 1s a slhcone film (Fig. Smce it IS well known that the dermis of the adult mammal does not regenerate spontaneously (12,13), the SRT 1s required for dermal regeneration in all commonly encountered skm wounds that are sufficiently deep to have compromised the dermis. One of these analogs, referred to as the skm regeneration template (SRT), has Induced regeneration of dermis in full-thickness skin wounds m the guinea pig model (2.5-7), the porcme model (8), and m humans (S,!Wl). The reader 1s referred to descriptions of these methods m the original literature (Z-3) The blologlcal actlvlty of ECM analogs has been revlewed elsewhere (4). Introduction Certain analogs of the extracellular matrix (ECM) have been shown to possess surprising morphogenetlc activity during healing of lessons m various anatomlcal sites This chapter describes methods for synthesis of the two ECM analogs that have been studied most extensively. Of Collager&lycosaminoglycan for Tissue Regenerationġ.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |