Thrombus formation and blood coagulation are serious problems associated with blood contacting products,such as catheters,vascular grafts,artificial hearts,and heart valves.Recent progresses and strategies to improve ...Thrombus formation and blood coagulation are serious problems associated with blood contacting products,such as catheters,vascular grafts,artificial hearts,and heart valves.Recent progresses and strategies to improve the hemocompatibility of biomaterials by surface modification using photochemical immobilization and photograft polymerization are reviewed in this paper.Three approaches to modify biomaterial surfaces for improving the hemocompatibility,i.e.,bioinert surfaces,immobilization of anticoagulative substances and biomimetic surfaces,are introduced.The biomimetic amphiphilic phosphorylcholine and Arg-Gly-Asp(RGD)sequence are the most effective and most often employed biomolecules and peptide sequence for improving hemocompatibility of material surfaces.The RGD sequence can enhance adhesion and growth of endothelial cells(ECs)on material surfaces and increase the retention of ECs under flow shear stress conditions.This surface modification is a promising strategy for biomaterials especially for cardiovascular grafts and functional tissue engineered blood vessels.展开更多
This article presents a simple,fast and low-cost method to fabricate a flexible UV light photomask.The designed micropatterns were directly printed onto transparent hybrid composite film of biaxially oriented polyprop...This article presents a simple,fast and low-cost method to fabricate a flexible UV light photomask.The designed micropatterns were directly printed onto transparent hybrid composite film of biaxially oriented polypropylene coated with silica oxide (BOPP-SiOx) by an inkjet printer.Compared to the conventional chrome-mask,it is of advantages such as suitable for non-planar substrates,scalable for large area production,and extreme low cost.Combined with the confined photo-catalytic oxidation (CPO) reaction,the printed flexible BOPP-SiOx photomask was successfully used to pattern the shape of wettability of organic polymer surfaces,and then polyaniline patterns were deposited on the modified substrates with strong adhesion.With the above photomasks,the polyacrylic acid graft chains were duplicated on the poly (ethylene terephthalate) (PET) and BOPP substrates by photografting polymerization.We grafted polyacrylic acid (PAA) on a non-planar plastic substrate with this soft and thin plastic photomask.Scanning electron microscopy (SEM) and optical microscopy were used to characterize the surface morphology and thickness of ink layers of the printed photomask.Optical microscopy was used to characterize the deposition polyaniline micropatterns.It was found that the desired patterns were precisely printed on the modified polymer films and were applied in modifying organic polymer substrates.The printed photomask could be exploited in the fields such as prototype microfluidics,micro-sensors,optical structures and any other kind of microstructures which does not require high durability and dimensional stability.展开更多
基金financially supported by Program for New Century Excellent Talents in University“NCET”,Ministry of Education of Chinathe International Cooperation from Ministry of Science and Technology of China(Grant No.2008DFA51170)sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China.
文摘Thrombus formation and blood coagulation are serious problems associated with blood contacting products,such as catheters,vascular grafts,artificial hearts,and heart valves.Recent progresses and strategies to improve the hemocompatibility of biomaterials by surface modification using photochemical immobilization and photograft polymerization are reviewed in this paper.Three approaches to modify biomaterial surfaces for improving the hemocompatibility,i.e.,bioinert surfaces,immobilization of anticoagulative substances and biomimetic surfaces,are introduced.The biomimetic amphiphilic phosphorylcholine and Arg-Gly-Asp(RGD)sequence are the most effective and most often employed biomolecules and peptide sequence for improving hemocompatibility of material surfaces.The RGD sequence can enhance adhesion and growth of endothelial cells(ECs)on material surfaces and increase the retention of ECs under flow shear stress conditions.This surface modification is a promising strategy for biomaterials especially for cardiovascular grafts and functional tissue engineered blood vessels.
基金supports from the Changjiang Scholars and Innovative Research Team in University (IRT 0706)Program of Introducing Talents of Discipline to Universities (B08003) are greatly appreciated
文摘This article presents a simple,fast and low-cost method to fabricate a flexible UV light photomask.The designed micropatterns were directly printed onto transparent hybrid composite film of biaxially oriented polypropylene coated with silica oxide (BOPP-SiOx) by an inkjet printer.Compared to the conventional chrome-mask,it is of advantages such as suitable for non-planar substrates,scalable for large area production,and extreme low cost.Combined with the confined photo-catalytic oxidation (CPO) reaction,the printed flexible BOPP-SiOx photomask was successfully used to pattern the shape of wettability of organic polymer surfaces,and then polyaniline patterns were deposited on the modified substrates with strong adhesion.With the above photomasks,the polyacrylic acid graft chains were duplicated on the poly (ethylene terephthalate) (PET) and BOPP substrates by photografting polymerization.We grafted polyacrylic acid (PAA) on a non-planar plastic substrate with this soft and thin plastic photomask.Scanning electron microscopy (SEM) and optical microscopy were used to characterize the surface morphology and thickness of ink layers of the printed photomask.Optical microscopy was used to characterize the deposition polyaniline micropatterns.It was found that the desired patterns were precisely printed on the modified polymer films and were applied in modifying organic polymer substrates.The printed photomask could be exploited in the fields such as prototype microfluidics,micro-sensors,optical structures and any other kind of microstructures which does not require high durability and dimensional stability.
