Study On Preparation And Modification Of Natural Extracellular Matrix

Tissue engineering is an important technique for treating the failure and decline of tissues andorgans, has been applied widely in clinics. Scaffold material is an important part of tissueengineering. As a natural scaffold, natural extracellular matrix has good biological compatibility,low immunity, no repulsion and infection. It is significative in tissue engineering. The componentand structure of it and extracellular matrix (ECM) are basically identical. In our research, we studyon the feasibility of preparing the natural porcine ECM scaffolds from a pig's different parts, inmembrane and pipe shape or being virtual organs, to be heterotransplanted to restore and replace thefunction of exhausted tissue and organ.We prepare natural porcine ECM scaffolds from different parts by enzymatic degradation method,in membrane and pipe shape or being virtual organs. The results prove that it can effectively removecells and reduce ECM's immunity.Although it has low immunity and good biological compatibility, but the mechanic intensity andanti-degradability of natural ECM can not satisfy clinical demand. We can improve the mechanicintensity and anti-degradability by modifying natural ECM. Meanwhile, modifying can help cellsconglutinate, spread, grow, proliferation and function express, and make cells and moleculeproduce differential discriminating sites of responses and expression of differential genes.We modify a pig's tissue ECM, in membrane and pipe shape or being virtual organs, byglutaraldehyde, N,N-dicyclohexylcarbodiimide, 1.2.7.8-diepoxyoctane and genipin crosslinking.We find that the crosslinking effects of this four crosslinking agents are different. Relativelyspeaking, the effect ofgenipin in the four crosslinking agents are the best in improving ECM'ssuture stretch rupture intensity, anti-degradability, cell toxicity and hemolysis.(1) Suture stretch rupture intensity: ECM crosslinking by genipin＞ECM crosslinking byglutaraldehyde＞ECM crosslinking by 1.2.7.8-diepoxyoctane＞ECM crosslinking byN,N-dicyclohexylcarbodiimide;(2) Anti-degradability: ECM crosslinking by genipin＞ECM crosslinking by 1.2.7.8-diepoxyoctane＞ECM crosslinking by N,N-dicyclohexylcarbodiimide＞ECMcrosslinking by glutaraldehyde;(3) Cell toxicity: ECM crosslinking by glutaraldehyde has the highest cell toxicity, and ECMcrosslinking by N,N-dicyclohexylcarbodiimide, 1.2.7.8-diepoxyoctane and genipin havelower cell toxicity;(4) Hemolysis: ECM crosslinking by glutaraldehyde and 1.2.7.8-diepoxyoctane have higherhemolysis, and ECM crosslinking by N,N-dicyclohexylcarbodiimide and genipin havelower hemolysis.Then, we modify the pig's derm, main artery, bladdar, pericardium, urethra, valve, peritoneumand ureter by genipin, discuss preparation methods and measure the functions of crosslinking products. Functions of ECM in membrane and pipe shape or being virtual organs after crosslinkingare different to some extent, but suture stretch rupture intensity and anti-degradability are allimproved, hemolysis is all conform to national standard.We cultivated epithelia cell onto 8 ECMs crosslinking by genipin, observe that cells grows wellon ECM scaffold materials. It primarily proves the feasibility of crosslinked natural ECMs in ourresearch, as tissue engineering scaffolds in application of tissue restorement and replacement. Itoffers a basis for future study of tissue replacers.