Here we report supramolecular hydrogelators made of nonsteroidal anti-inflammatory drugs (NSAID) and small peptides. The covalent linkage of Phe–Phe and NSAIDs results in conjugates that self-assemble in water to form molecular nanofibers as the matrices of hydrogels. When the NSAID is naproxen (1), the resultant hydrogelator 1a forms a hydrogel at a critical concentration (cgc) of 0.2 wt % at pH 7.0. Hydrogelator 1a, also acting as a general motif, enables enzymatic hydrogelation in which the precursor turns into a hydrogelator upon hydrolysis catalyzed by a phosphatase at physiological conditions. The conjugates of Phe–Phe with other NSAIDs, such as (R)-flurbiprofen (2), racemic flurbiprofen (3), and racemic ibuprofen (4), are able to form molecular hydrogels, except in the case of aspirin (5). After the conjugation with the small peptides, NSAIDs exhibit improved selectivity to their targets. In addition, the peptides made of D-amino acids help preserve the activities of NSAIDs. Besides demonstrating that common NSAIDs are excellent candidates to promote aromatic–aromatic interaction in water to form hydrogels, this work contributes to the development of functional molecules that have dual or multiple roles and ultimately may lead to new molecular hydrogels of therapeutic agents for topical use.
在这里,我们报告了由非甾体抗炎药(NSAID)和小肽组成的超分子水凝胶剂。Phe–Phe和NSAIDs的共价连接产生了在水溶液中自组装形成分子纳米纤维作为水凝胶基质的偶联物。当NSAID是萘普生(1)时,所得的水凝胶剂1a在pH 7.0的临界浓度(cgc)为0.2 wt%时形成水凝胶。水凝胶剂1a,也作为一种通用结构,能够进行酶促水凝胶化,即前体在生理条件下经磷酸酶催化的水解转变为水凝胶剂。Phe–Phe与其他NSAIDs,如(R)-氟比洛芬(2)、消旋氟比洛芬(3)和消旋布洛芬(4)的偶联物能够形成分子水凝胶,但在阿司匹林(5)的情况下则不能。与小肽偶联后,NSAIDs对其靶标的选择性得到提高。此外,由D-氨基酸组成的小肽有助于保持NSAIDs的活性。除了证明常见的NSAIDs是促进水溶液中芳香族-芳香族相互作用以形成水凝胶的优秀候选者外,这项工作还促进了具有双重或多重功能的功能分子的发展,并最终可能导致用于外用治疗剂的新型分子水凝胶的产生。