ABSTRACT
Objective Xenografts have poor biocompatibilities,the aim of this study was to improve the biocompatibilities of decellular xenografts via heparin/dihydroxy-iron complex multilayeres (HDCMs) nanomodification.Methods A novel thrombo-resistant surface for decellular xenograft had been developed by alternating linkage of dihydroxy-iron and heparin to decellular bovine jugular vein (DC-BJV),and surface characterization and biocompatibility of HDCMs nanomodified BJV (HDCMs-BJV) were detected.Results Toluidine blue colorimetric method showed the amount of linked heparin was about (808 ±86) μg/cm2 per assembly-cycle.SEM images proved HDCMs were uniformly linked to and formed nanoscale films around the fibrils of DC-BJV.Washing test proved HDCMs were firmly linked to BJV and sustainedly released heparin for a long time.Tensile test showed that biomechanical stability was increased.Antithrombogenicity test showed that the activated partial thrombin time (APTT) and prothrombin time (PT) of all trial groups were above the normal reference ranges.Platelet adhesion test evaluated mean platelet count per 10 000 μm2 area was 8 ±4 for HDCMs-BJV vs.48 ± 16 for DC-BJV.Endothelial cells (ECs) proliferation test showed the number and activity of ECs on luminal surface of HDCMs-BJV were very similar to DC-BJV at 7-day incubation.Calcium content assay evaluated mean calcium content was ( 8.5 ± 1.9 ) μg/mg dry weight for HDCMs-BJV vs.(26.6 ± 3.7) μg/mg dry weight for DC-BJV at 4 weeks and (21.5 ± 6.8 ) μg/mg dry weight for HDCMsBJV vs.( 112.6 ± 16.9) μg/mg dry weight for DC-BJVs at 8 weeks,respectively.Conclusion These results demonstrate HDCMs were firmly linked to BJV and formed nanoscale thrombo-resistant films,and HDCMs nanomodification improves biocompatibilities of decellular xenograft.
ABSTRACT
OBJECTIVE@#To improve the hemocompatibility of decellular vascular matrix via heparin-iron complex multilayers (HICMs) nanomodification.@*METHODS@#A novel thrombo-resistant surface for decellular xenograft was developed by alternating linkage of dihydroxy-iron and heparin to decellular bovine jugular vein (DC-BJV), and its surface characterization, biomechanical stability and hemocompatibility were detected by scanning electron microscopy, tensile test and hemocompatibility evaluation, respectively.@*RESULTS@#A toluidine blue colorimetric method indicated the amount of linked heparin was about (808±86) μg/cm2 per assembly-cycle. Scanning electron microscopic (SEM) images proved that HICMs were uniformly linked to and formed nanoscale films around the fibrils of DC-BJV. Toluidine blue staining histologic images showed that HICMs were linked mainly to DC-BJV surfaces. Washing test showed that the release of heparin was (281±43), (422 ± 60), (729±81), (1053±116), (1317±157), (1618±187) and (1945 ± 268 ) μg/cm(2) at 1 day, 1, 2, 3, 4, 6 and 8 week washing, respectively. Tensile tests showed an increased biomechanical stability. Hemocompatibility evaluations showed that PT and APTT of all the trial groups were above the normal reference ranges and that mean platelet count per 10000 μm2 area was 8±4 for HICMs layer-by-layer modified BJV (LBL-BJV) vs 48±16 for DC-BJV.@*CONCLUSION@#HICMs are firmly linked to DC-BJV, and can form nanoscale thrombo-resistant films, which yield a sustained release of heparin. HICMs nanomodification improves the hemocompatibility of decellular xenograft.