BACKGROUND: The degradable poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) has superior mechanical property and biocompatibility.OBJECTIVE: To elucidate the intravascular biocompatibility of PHBHHx in vivo.METHODS: We developed hybrid materials based on decellularized xenogenic vascular scaffolds that were coated with PHBHHx and implanted it into the abdominal aorta of New Zealand rabbits. The decellularized xenogenic pulmonary artery patch without PHBHHx coating served as the control. The implanted patches were determined for the histology, immunofluorescence staining, scanning electron microscopy and calcium contents at 1, 4 and 12 weeks after the surgery.RESULTS AND CONCLUSION: Hybrid patches exhibited smooth lumen surface without thrombus, the intimal hyperplasia was mild and recellularization was complete; immunofluorescence staining showed that the endothelial cells in the neointima were positive for CD31, with continuous single-layer arrangement, interstitial cells were positive for smooth muscle actin; the calcium content in hybrid patches was obviously lower than that in uncoated patches. PHBHHx shows a remarkable intravascular biocompatibility in vivo and is believed as an ideal candidate for lumen coating of cardiovascular tissue engineering.

Poly (3-hydroxybutyrate-co-3-hydroxyhexanoate, PHBHHx) has superior mechanical and biocompatibility that may enable it to meet cardiovascular tissue engineering applications. We developed hybrid materials based on decellularized xenogenic vascular scaffolds that were coated with PHBHHx to investigate the intravascular biocompatibility. The hybrid patches were implanted in the rabbit abdominal aorta (hybrid patch, n = 12). Only decellularized xenogenic vascular scaffolds were implanted without coating as control (uncoated patch, n = 12). The patches were explanted and examined histologically, and biochemically at 1, 4 and 12 weeks after the surgery. The hybrid patches maintained original shapes, covered by confluent layer of cells and had less calcification than uncoated control. The results indicated that PHBHHx coating reduced calcification, promoted the repopulation of hybrid patch with recipients cells. In conclusion, PHBHHx showed remarkable intravascular biocompatibility and would benefit endothelization which would be a useful candidate for lumen of cardiovascular tissue engineering.
3-Hydroxybutyric Acid ; chemistry ; Animals ; Aorta, Abdominal ; surgery ; Caproates ; chemistry ; Cell Adhesion ; Coated Materials, Biocompatible ; chemistry ; pharmacology ; Goats ; Humans ; Implants, Experimental ; Pulmonary Artery ; cytology ; drug effects ; Rabbits ; Surface Properties ; Tissue Engineering ; Tissue Scaffolds

OBJECTIVE To investigate the treatment plan for az treonam-resistant metallo- β-lactamase（MBL）-producing Enterobacteriaceae infection in pediatric solid organ transplant recipients. METHODS The clinical data of aztreonam-resistant MBL-producing Klebsiella pneumoniae caused intra-abdominal infection of an infant after liver transplantation were retrospectively analyzed. Abdominal infection occurred after operation. The pathogenic bacterium was MBL-producing K. pneumoniae . The drug sensitivity results showed that the infant was resistant to aztreonam. Based on the results of sensitivity test ，polymyxin B combined with tigecycline were selected as initial regimen. The treatment effect was poor ，with recurrent disease and shock spots. The clinical pharmacist assisted the clinician to formulate treatment regimen of ceftazidime avibactam 0.5 g，q8 h combined with aztreonam 0.18 g，q6 h. Relevant domestic and foreign literature were reviewed ，and the treatment plan of MBL-producing Enterobacteriaceae infection after solid organ transplantation was summarized. RESULTS & CONCLUSIONS The infant was finally cured and discharged with ceftazidime avibatan combined and aztreonam. Several foreign literature reported that ceftazidime avibactam combined with aztreonam could effectively treat the infection caused by aztreonam-resistant MBL-producing Enterobacteriaceae infection in patients with organ transplantation. It is expected to be an effective treatment for aztreonam-resistant MBL-producing Enterobacteriaceae infection in pediatric solid organ transplant recipients.