University of Tromsø, Drug Transport and Delivery Research Group, Department of Pharmacy, Universitetsveien 57, N-9037 Tromsø, Norway.
Int J Pharm. 2013 Nov 1;456(1):49-57. doi: 10.1016/j.ijpharm.2013.08.033. Epub 2013 Aug 27.
To study the release of liposome-associated drugs into hydrogels, we designed and synthesized two pH-sensitive rhodamine derivatives to use as model compounds of different lipophilicities. The dyes were fluorescent when in the free form released from liposomes into the chitosan hydrogel, but not when incorporated within liposomes. The effect of liposomal composition, surface charge and vesicle size on the release of those incorporated dyes was evaluated. The lipophilicity of the rhodamine derivatives affected both the amount and rate of release. While liposome size had only a minor effect on the release of dyes into the hydrogel, the surface charge affected the release to a greater extent. By optimizing the characteristics of liposomes we could develop a liposomes-in-hydrogel system for application in wound therapy. We further characterized liposomes-in-hydrogel for their rheological properties, textures and moisture handling, as well as their potential to achieve a controlled release of the dye. The polymer-dependent changes in the hydrogel properties were observed upon addition of liposomes. The charged liposomes exhibited stronger effects on the textures of the chitosan hydrogels than the neutral ones. In respect to the ability of the system to handle wound exudates, chitosan-based hydrogels were found to be superior to Carbopol-based hydrogels.
为了研究脂质体相关药物在水凝胶中的释放情况，我们设计并合成了两种 pH 敏感的罗丹明衍生物，用作不同亲脂性的模型化合物。当从脂质体中释放到壳聚糖水凝胶中时，染料以游离形式是荧光的，但当包含在脂质体中时则不是。评估了脂质体组成、表面电荷和囊泡大小对这些包含的染料释放的影响。罗丹明衍生物的亲脂性影响了释放到水凝胶中的量和速率。虽然脂质体大小对染料进入水凝胶的释放只有较小的影响，但表面电荷的影响更大。通过优化脂质体的特性，我们可以开发出一种脂质体-水凝胶系统，用于伤口治疗。我们进一步研究了脂质体-水凝胶的流变学特性、质地和水分处理，以及控制染料释放的潜力。在添加脂质体时观察到水凝胶性质的聚合物依赖性变化。带电荷的脂质体对壳聚糖水凝胶的质地的影响比中性脂质体更强。在处理伤口渗出物的能力方面，壳聚糖基水凝胶优于 Carbopol 基水凝胶。
