He Hongyan, Cao Xia, Lee L James
Department of Chemical Engineering, The Ohio State University, 140 W. 19th Avenue, Columbus, OH 43210, USA.
J Control Release. 2004 Mar 24;95(3):391-402. doi: 10.1016/j.jconrel.2003.12.004.
The present work focused on the design of an assembled drug delivery system (DDS) to provide multifunctions, such as drug protection, self-regulated oscillatory release, and targeted uni-directional delivery by a bilayered self-folding gate and simple surface mucoadhesion. In this device, a pH-sensitive hydrogel together with a poly(hydroxyethyl methacrylate) (HEMA) barrier was used as a gate to control drug release. In addition, poly(HEMA) coated with poly(ethylene oxide)/poly(propylene oxide)/poly(ethylene oxide) (PEO-PPO-PEO) surfactant was utilized to enhance mucoadhesion on the device surface. The release profiles of two model drugs, acid orange 8 (AO8) and bovine serum albumin (BSA) were studied in this assembled system, which compared with the conventional drug-entrapped carriers and enteric-coating systems. Furthermore, targeted uni-directional release was demonstrated in a side-by-side diffusion cell. In conclusion, for such an assembled device, the poly(HEMA) layer not only affects the folding direction but also serves as a barrier to protect the model drugs. The release time can be controlled by the thickness of the bilayered gate and the drug reservoir. Due to the reversible swelling behavior of poly(methyacrylic acid-g-ethylene glycol) (p(MAA-g-EG)) gels, the bilayered gate can sense the environmental pH change and achieve an oscillatory release pattern. Moreover, the local targeting and uni-directional release have been successfully demonstrated in vitro.
本研究致力于设计一种组装式药物递送系统（DDS），以实现多种功能，如药物保护、自调节振荡释放，以及通过双层自折叠门和简单的表面粘膜粘附实现靶向单向递送。在该装置中，pH敏感水凝胶与聚甲基丙烯酸羟乙酯（HEMA）屏障一起用作控制药物释放的门。此外，涂有聚环氧乙烷/聚环氧丙烷/聚环氧乙烷（PEO-PPO-PEO）表面活性剂的聚（HEMA）用于增强装置表面的粘膜粘附性。在该组装系统中研究了两种模型药物酸性橙8（AO8）和牛血清白蛋白（BSA）的释放曲线，并与传统的载药载体和肠溶包衣系统进行了比较。此外，在并排扩散池中证明了靶向单向释放。总之，对于这样一种组装装置，聚（HEMA）层不仅影响折叠方向，还作为保护模型药物的屏障。释放时间可通过双层门和药物储存器的厚度来控制。由于聚（甲基丙烯酸-g-乙二醇）（p（MAA-g-EG））凝胶的可逆溶胀行为，双层门可以感知环境pH变化并实现振荡释放模式。此外，已在体外成功证明了局部靶向和单向释放。
