In-Vitro Biocompatibility Determination of Bladder Acellular Matrix Graft
In-vitro biocompatibility testing of bladder acellular matrix graft (BAMG) was carried out after cross-linking with 0.6% Glutaraldehyde (GA), 1% Hexamethylene diisocyanate (HMD), 1% 1,4-butanediol diglycidyl ether (BDDGE) and 1% 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) for 12, 24, 48 and 72 h duration at room temperature. The uncross-linked acellular bladder was used as control. In-vitro studies included enzymatic degradation (collagenase, elastase and trypsin), free amino group determination, moisture content percentage, molecular weight analysis using SDS-PAGE and free protein content estimation. Enzymatic degradation was carried out by treating BAMG with collagenase (20 U/ml), elastase (0.1 U/ml) and trypsin (0.004 Anson U/ml). HMD treated biomaterials were found highly resistant among the cross-linked samples to enzymatic degradation. The GA and HMD treated bladder acellular matrix had greatest reduction in free amino group contents in comparison to EDC, BDDEGE and control samples. The maximum dehydration (least moisture content) was recorded in EDC treated BAMG, followed by HMD, BDDGE and GA treated samples at respective time intervals. In SDS-PAGE the GA and EDC treated samples did not show any band pattern whereas, HMD and BDDGE showed protein bands almost similar to that of acellular bladder (control), but were of reduced density and less intensity. Reduction in the free protein contents was minimum in HMD cross-linked samples, while it was maximum in GA and EDC treated samples.