Hamidi Mehrdad, Azadi Amir, Rafiei Pedram
Faculty of Pharmacy, Shiraz University of Medical Sciences, P.O. Box 71345-1583, Shiraz, Iran.
Adv Drug Deliv Rev. 2008 Dec 14;60(15):1638-49. doi: 10.1016/j.addr.2008.08.002. Epub 2008 Sep 20.
Hydrogel nanoparticles have gained considerable attention in recent years as one of the most promising nanoparticulate drug delivery systems owing to their unique potentials via combining the characteristics of a hydrogel system (e.g., hydrophilicity and extremely high water content) with a nanoparticle (e.g., very small size). Several polymeric hydrogel nanoparticulate systems have been prepared and characterized in recent years, based on both natural and synthetic polymers, each with its own advantages and drawbacks. Among the natural polymers, chitosan and alginate have been studied extensively for preparation of hydrogel nanoparticles and from synthetic group, hydrogel nanoparticles based on poly (vinyl alcohol), poly (ethylene oxide), poly (ethyleneimine), poly (vinyl pyrrolidone), and poly-N-isopropylacrylamide have been reported with different characteristics and features with respect to drug delivery. Regardless of the type of polymer used, the release mechanism of the loaded agent from hydrogel nanoparticles is complex, while resulting from three main vectors, i.e., drug diffusion, hydrogel matrix swelling, and chemical reactivity of the drug/matrix. Several crosslinking methods have been used in the way to form the hydrogel matix structures, which can be classified in two major groups of chemically- and physically-induced crosslinking.
近年来，水凝胶纳米颗粒作为最具前景的纳米颗粒药物递送系统之一受到了广泛关注，这是因为它通过将水凝胶系统的特性（如亲水性和极高的含水量）与纳米颗粒的特性（如非常小的尺寸）相结合，具有独特的潜力。近年来，基于天然和合成聚合物制备并表征了几种聚合物水凝胶纳米颗粒系统，每种系统都有其自身的优缺点。在天然聚合物中，壳聚糖和藻酸盐已被广泛研究用于制备水凝胶纳米颗粒；在合成聚合物中，基于聚乙烯醇、聚环氧乙烷、聚乙烯亚胺、聚乙烯吡咯烷酮和聚N-异丙基丙烯酰胺的水凝胶纳米颗粒也已被报道，它们在药物递送方面具有不同的特性。无论使用何种类型的聚合物，负载药物从水凝胶纳米颗粒中的释放机制都很复杂，它由三个主要因素导致，即药物扩散、水凝胶基质溶胀以及药物/基质的化学反应性。已采用多种交联方法来形成水凝胶基质结构，这些方法可分为化学诱导交联和物理诱导交联两大类。
