Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States.
Department of Bioengineering, School of Medicine & School of Engineering, Stanford University, Stanford, California 94305, United States.
Biomacromolecules. 2024 Feb 12;25(2):1274-1281. doi: 10.1021/acs.biomac.3c01242. Epub 2024 Jan 19.
We have studied the complexation between cationic antimicrobials and polyanionic microgels to create self-defensive surfaces that responsively resist bacterial colonization. An essential property is the stable sequestration of the loaded (complexed) antimicrobial within the microgel under a physiological ionic strength. Here, we assess the complexation strength between poly(acrylic acid) [PAA] microgels and a series of cationic peptoids that display supramolecular structures ranging from an oligomeric monomer to a tetramer. We follow changes in loaded microgel diameter with increasing [Na] as a measure of the counterion doping level. Consistent with prior findings on colistin/PAA complexation, we find that a monomeric peptoid is fully released at ionic strengths well below physiological conditions, despite its +5 charge. In contrast, progressively higher degrees of peptoid supramolecular structure display progressively greater resistance to salting out, which we attribute to the greater entropic stability associated with the complexation of multimeric peptoid bundles.
我们研究了阳离子型抗菌剂与聚阴离子型微凝胶之间的络合作用，以创造具有响应性的自我防御表面，从而抵抗细菌定植。一个重要的性质是在生理离子强度下，负载（络合）抗菌剂在微凝胶内的稳定螯合。在这里，我们评估了一系列具有从低聚物单体到四聚体的超分子结构的阳离子肽的聚（丙烯酸）[PAA]微凝胶之间的络合强度。我们随着[Na]的增加来跟踪负载微凝胶直径的变化，以此作为抗衡离子掺杂水平的度量。与多粘菌素/PAA 络合的先前发现一致，我们发现尽管单体肽具有+5 电荷，但在远低于生理条件的离子强度下，它完全被释放。相比之下，肽的超分子结构程度越高，对盐析的抵抗力就越大，我们将其归因于与多聚体肽束络合相关的更大的熵稳定性。
