Poly(N-isopropylacrylamide),Poly(methacrylic acid)and Their Copolymers for Oral Colon-specific Drug

来源 :武汉理工大学学报(材料科学版)(英文版) | 被引量 : 0次 | 上传用户:AdamMYS
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
A series of cross-linked gels of Poly(N-isopropylacrylamide)[P(NIPAAm)]and Poly(methacr-ylic acid)[P(MAA)]homopolymers and P(NIPAAm-co-MAA)random copolymers were synthesized based on NIPAAm and MAA using 4,4-Bis-(methacryloylamino)azobenzene (BMAAB)as a cross-linker.The swelling behavior of these hydrogels in different pH buffer solu-tions was studied.The influential factors of the gels including composition of NIPAAm and MAA, pH and temperature upon swelling behavior were investigated.The obtained gels not only hold pH and thermometrical sensitivity,but also take on enzymatic sensitivity due to the cross-linker could be degraded by enzymes of colon.Swelling equilibrium degree of copolymers was very low in acidic medium,which could avoid drug releasing due to biggish swelling of carrier in stomach.Hydrogels would partly swell owing to higher pH value in small intestine.When arrived in colon,hydrogels completely swelled,meanwhile,azoenzymes located would degrade azo-bonds of polymeric network and then drug released in colon.
其他文献
Spinel zinc ferrites ZnFe_2O)4,prepared by co-precipitation method using the zinc nitrate Zn(NO_3)_2·6H_2O and ferric nitrate Fe(NO_3)_3·2H_2O as the raw materials,were characterized by the thermo gravimetric analysis(TG)and differential scanning calorime
The effects of fly ash and MgO-type expansive agent on the shrinkage and expan-sive strain of concrete with high magnesia cement were investigated. The results show that high volumes of fly ash may reduce the shrinkage strain of concrete and inhibit the e
The changes of induced bone with four kinds of Ca-P ceramics after 2 years im-plantation in the dorsal muscles of rabbits were investigated.After 2 years implantation,mature bone (with a lamellar structure after the remodeling process)with bone marrow was
A micro-envioment for nerve cells and tissue growth were designed and constructed via surface modification of poly(L-lactide-co-glycolide)(PLGA)with chitosan and hydroxyapa-tite(HA).The poly(L-lactide-co-glycolide)/chitosan/hydroxyapatite(PLGA/chitosan/HA
Formation and growth of the intermediate phases in the Ni-Al diffusion couples prepared by pouring technique were investigated.Electron probe microanalysis,scanning electron microscopy and X-ray diffraction were used to characterize the product phases in
Calcium montmorillonite from Liao-ning was organically intercalated by using cety1 trimethy1 ammonium bromide after it was treated with sodium carbonate.The optimal dosage of intercalating agent was tested.The organically intercalated montmorillonite comp