Mealy Joshua E, Rodell Christopher B, Burdick Jason A
210 S 33 St, 240 Skirkanich Hall, Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104.
J Mater Chem B. 2015 Oct 28;3(40):8010-8019. doi: 10.1039/C5TB00981B. Epub 2015 Sep 18.
Self-assembled and injectable hydrogels have many beneficial properties for the local delivery of therapeutics; however, challenges still exist in the sustained release of small molecules from these highly hydrated networks. Host-guest chemistry between cyclodextrin and adamantane has been used to create supramolecular hydrogels from modified polymers. Beyond assembly, this chemistry may also provide increased drug retention and sustained release through the formation of inclusion complexes between drugs and cyclodextrin. Here, we engineered a two-component system from adamantane-modified and β-cyclodextrin (CD)-modified hyaluronic acid (HA), a natural component of the extracellular matrix, to produce hydrogels that are both injectable and able to sustain the release of small molecules. The conjugation of cyclodextrin to HA dramatically altered its affinity for hydrophobic small molecules, such as tryptophan. This interaction led to lower molecule diffusivity and the release of small molecules for up to 21 days with release profiles dependent on CD concentration and drug-CD affinity. There was significant attenuation of release from the supramolecular hydrogels (20% release in 24h) when compared to hydrogels without CD (90% release in 24h). The loading of small molecules also had no effect on hydrogel mechanics or self-assembly properties. Finally, to illustrate this controlled delivery approach with clinically used small molecule pharmaceuticals, we sustained the release of two widely used drugs (i.e., doxycycline and doxorubicin) from these hydrogels.
自组装且可注射的水凝胶对于治疗药物的局部递送具有许多有益特性;然而,从小分子在这些高度水合网络中的持续释放方面来看,挑战依然存在。环糊精与金刚烷之间的主客体化学已被用于由改性聚合物制备超分子水凝胶。除了组装之外,这种化学作用还可通过药物与环糊精之间形成包合物来提高药物保留率并实现持续释放。在此,我们利用金刚烷改性的和β - 环糊精(CD)改性的透明质酸(HA,细胞外基质的一种天然成分)构建了一种双组分体系,以制备既具有可注射性又能够持续释放小分子的水凝胶。环糊精与HA的共轭显著改变了其对疏水性小分子(如色氨酸)的亲和力。这种相互作用导致分子扩散率降低,并使小分子在长达21天的时间内持续释放,释放曲线取决于CD浓度和药物 - CD亲和力。与不含CD的水凝胶(24小时内释放约90%)相比,超分子水凝胶的释放有显著衰减(24小时内释放约20%)。小分子的负载对水凝胶的力学性能或自组装特性也没有影响。最后,为了用临床使用的小分子药物来说明这种控释方法,我们使两种广泛使用的药物(即强力霉素和阿霉素)从这些水凝胶中持续释放。