School of Chemical Engineering, Theranostic Macromolecules Research Center, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
School of Chemical Engineering, Theranostic Macromolecules Research Center, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
J Control Release. 2017 Dec 10;267:57-66. doi: 10.1016/j.jconrel.2017.08.006. Epub 2017 Aug 4.
Hydrogels are natural or synthetic polymer networks that exhibit high water absorbent capacities and have been used as scaffolds for tissue engineering or as delivery carriers for therapeutic agents and cells. Owing to their tunable physicochemical properties, hydrogels can provide spatial and temporal control over the release of loaded therapeutic agents, including chemotherapeutic drugs, proteins or cells. In particular, in situ-forming injectable hydrogels, the state-of-the-art clear free flowing polymer solutions that transform to viscoelastic gels upon exposure to stimuli including pH, temperature, light, enzymes and magnetic field, have been widely studied as delivery carriers for therapeutic agents. Therapeutic agents can be easily mixed with the free flowing polymer solutions and injected into the subcutaneous tissue or target site that could form a viscoelastic gel and act as therapeutic agents release depot. Hence, injectable hydrogels paid attention as sustained delivery vehicles. In this review, we systematically summarize the development of biocompatible, biodegradable, and pH- and temperature-responsive injectable hydrogels for sustained release of therapeutic agents. The key factors responsible for in situ gelation, interaction between polymers and therapeutic agents, and controlling the degradation of hydrogel matrix, are discussed. Advantages and perspectives of pH- and temperature-responsive injectable hydrogels in sustained therapeutic agents release are highlighted.
水凝胶是具有高吸水性的天然或合成聚合物网络，已被用作组织工程的支架或治疗剂和细胞的递送载体。由于其可调节的物理化学性质，水凝胶可以提供对负载治疗剂释放的时空控制，包括化疗药物、蛋白质或细胞。特别是，原位形成的可注射水凝胶是最先进的透明无定形聚合物溶液，在受到包括 pH 值、温度、光、酶和磁场等刺激时会转化为粘弹性凝胶，已被广泛研究作为治疗剂的递送载体。治疗剂可以很容易地与无定形聚合物溶液混合，并注射到皮下组织或靶部位，在那里可以形成粘弹性凝胶并作为治疗剂的释放库。因此，可注射水凝胶作为持续释放载体受到关注。在这篇综述中，我们系统地总结了用于治疗剂持续释放的生物相容性、可生物降解和 pH 和温度响应性可注射水凝胶的发展。讨论了负责原位凝胶化的关键因素、聚合物和治疗剂之间的相互作用以及控制水凝胶基质降解的因素。强调了 pH 和温度响应性可注射水凝胶在持续治疗剂释放方面的优势和前景。
