Electrolytic detachable coils (EDC) have been the main embolic materi als for intracranial aneurysms. Liquid aneurysmal embolic materials represented by cellulose acetate polymer (CAP) are still in controversy. In thi...Electrolytic detachable coils (EDC) have been the main embolic materi als for intracranial aneurysms. Liquid aneurysmal embolic materials represented by cellulose acetate polymer (CAP) are still in controversy. In this research, t he embolization results and pathological reactions after embolization of canine aneurysmal models with EDC or CAP were observed and compared. Methods. The canine aneurysmal models constructed by anastomosis of venous pouch es were randomly grouped. The aneurysms were respectively occluded with CAP and electrolytic detachable coils that was named by Wu electrolytic detachable coil (WEDC) and made by us. Angiogram follow ups were performed at 24 hour, 2 week , and 2 month after embolization. The occluded aneurysms were dissected in each stage for light microscopic, electron microscopic, and histochemical research. Results. The effect of embolization was significantly better with WEDC than that with CAP . Post embolized complications such as aneurysm rupture and stenosis of parent arteries could only be found in CAP group. Pathol ogical research showed that CAP mass could packed the aneurysms more densely tha n coils. Acute chemical damage of aneurysmal wall and inflammatory cell infiltra tion was prominently found in early stage after CAP embolization. Organization of thrombus inside aneurysms and formation of endothelial tissue over the orific es of aneurysmal necks could be found in both groups 2 months after embolization . But parts of coils might be exposed outside endothelial layer. Conclusions. EDC are still the most safe, efficient, and reliable instruments to embolize aneurysm. CAP should be improved further to solve the problem of stron g chemical corrosion and difficulty in control before it is widely used.展开更多
Currently-used mechanical and biological heart valve prostheses have a satisfactory short-term performance, but may exhibit several major drawbacks on the long-term. Mechanical prostheses, based on carbon, metallic an...Currently-used mechanical and biological heart valve prostheses have a satisfactory short-term performance, but may exhibit several major drawbacks on the long-term. Mechanical prostheses, based on carbon, metallic and polymeric components, require permanent anticoagulation treatment, and their usage often leads to adverse reactions, e.g. thromboembolic complications and endocarditis. In recent years, there is a need for a heart valve prosthesis that can grow, repair and remodel. The concept of tissue engineering offers good prospects into the development of such a device. An ideal scaffold should mimic the structural and purposeful profile of materials found in the natural extracellular matrix (ECM) architecture. The goal of this study was to develop cellulose acetate scaffolds (CA) for valve tissue regeneration. After their thorough physicochemical and biological characterization, a biofunctionalization process was made to increase the cell proliferation. Especially, the surface of scaffolds was amplified with functional molecules, such as RGD peptides (Arg-Gly-Asp) and YIGSRG laminins (Tyrosine-Isoleucine-Glycine-Serine-Arginine-Glycine) which immobilized through biotin-streptavidin bond, the strongest non-covalent bond in nature. Last step was to successfully coat an aortic metallic valve with CA biofunctionallized nanoscaffolds and cultivate cells in order to create an anatomical structure comparable to the native valve. Promising results have been obtained with CA-based nanoscaffolds. We found that cells grown successfully on the biofunctionalized valve surface thereby scaffolds that resemble the native tissues, elaborated with bioactive factors such as RGD peptides and laminins not only make the valve’s surface biocompatible but also they could promote endothyliazation of cardiac valves causing an anti-coagulant effect展开更多
文摘Electrolytic detachable coils (EDC) have been the main embolic materi als for intracranial aneurysms. Liquid aneurysmal embolic materials represented by cellulose acetate polymer (CAP) are still in controversy. In this research, t he embolization results and pathological reactions after embolization of canine aneurysmal models with EDC or CAP were observed and compared. Methods. The canine aneurysmal models constructed by anastomosis of venous pouch es were randomly grouped. The aneurysms were respectively occluded with CAP and electrolytic detachable coils that was named by Wu electrolytic detachable coil (WEDC) and made by us. Angiogram follow ups were performed at 24 hour, 2 week , and 2 month after embolization. The occluded aneurysms were dissected in each stage for light microscopic, electron microscopic, and histochemical research. Results. The effect of embolization was significantly better with WEDC than that with CAP . Post embolized complications such as aneurysm rupture and stenosis of parent arteries could only be found in CAP group. Pathol ogical research showed that CAP mass could packed the aneurysms more densely tha n coils. Acute chemical damage of aneurysmal wall and inflammatory cell infiltra tion was prominently found in early stage after CAP embolization. Organization of thrombus inside aneurysms and formation of endothelial tissue over the orific es of aneurysmal necks could be found in both groups 2 months after embolization . But parts of coils might be exposed outside endothelial layer. Conclusions. EDC are still the most safe, efficient, and reliable instruments to embolize aneurysm. CAP should be improved further to solve the problem of stron g chemical corrosion and difficulty in control before it is widely used.
文摘Currently-used mechanical and biological heart valve prostheses have a satisfactory short-term performance, but may exhibit several major drawbacks on the long-term. Mechanical prostheses, based on carbon, metallic and polymeric components, require permanent anticoagulation treatment, and their usage often leads to adverse reactions, e.g. thromboembolic complications and endocarditis. In recent years, there is a need for a heart valve prosthesis that can grow, repair and remodel. The concept of tissue engineering offers good prospects into the development of such a device. An ideal scaffold should mimic the structural and purposeful profile of materials found in the natural extracellular matrix (ECM) architecture. The goal of this study was to develop cellulose acetate scaffolds (CA) for valve tissue regeneration. After their thorough physicochemical and biological characterization, a biofunctionalization process was made to increase the cell proliferation. Especially, the surface of scaffolds was amplified with functional molecules, such as RGD peptides (Arg-Gly-Asp) and YIGSRG laminins (Tyrosine-Isoleucine-Glycine-Serine-Arginine-Glycine) which immobilized through biotin-streptavidin bond, the strongest non-covalent bond in nature. Last step was to successfully coat an aortic metallic valve with CA biofunctionallized nanoscaffolds and cultivate cells in order to create an anatomical structure comparable to the native valve. Promising results have been obtained with CA-based nanoscaffolds. We found that cells grown successfully on the biofunctionalized valve surface thereby scaffolds that resemble the native tissues, elaborated with bioactive factors such as RGD peptides and laminins not only make the valve’s surface biocompatible but also they could promote endothyliazation of cardiac valves causing an anti-coagulant effect
