Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, c/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
CIBER de Bioingeniería, Biomateriales y Nanomedicina, Instituto de Salud Carlos III, 28029 Madrid, Spain.
Nanoscale. 2022 Apr 21;14(16):5999-6006. doi: 10.1039/d1nr08223j.
Developing artificial metalloenzymes that possess a superior performance to their natural counterparts is an attractive concept. Polyoxometalates (POMs) are a class of anionic molecular metal-oxides with excellent redox properties and bioactivity. We have recently introduced "POMlymers" - covalently conjugated POM-peptide hybrid materials - where the polypeptide chain is obtained through a ring-opening polymerisation (ROP) of α-amino acid -carboxyanhydrides (NCA) on an inorganic POM scaffold. Attracted by the idea of preparing artificial metalloenzymes, here we report the supramolecular self-assembly of POMlymer hybrids into nanoparticles where an optimal environment for catalysis is created. Our results demonstrate that the self-assembly of covalent POMlymers, enhances the peroxidase-like activity of the parent POM anion whereas, in contrast, the catalytic activity for nanoparticles obtained by ionic self-assembly of the same peptide and POM components practically disappears. Furthermore, POMlymer nanoparticles also present antimicrobial and antibiofilm activity against the skin bacterium ; whereas, ionic POM-peptide hybrids significantly increase biofilm production and endogenous production of reactive oxygen species. In summary, we present the self-assembly of POMlymer hybrids into nanoparticles and a combination of peroxidase activity and microbiology assays that show that the POM-peptide covalent bond is essential for the stability of the self-assembled nanoparticles and therefore for their catalytic and biological activity.
开发具有优于天然对应物性能的人工金属酶是一个很有吸引力的概念。多金属氧酸盐（POMs）是一类具有优异氧化还原性质和生物活性的阴离子分子金属氧化物。我们最近引入了“POMlymers”-通过开环聚合（ROP）在无机 POM 支架上聚合α-氨基酸-羧基酸酐（NCA）得到的共价连接的 POM-肽杂化材料。受制备人工金属酶的想法的吸引，我们在这里报告了 POMlymer 杂化物在纳米颗粒中的超分子自组装，在那里创造了有利于催化的最佳环境。我们的结果表明，共价 POMlymers 的自组装增强了母体 POM 阴离子的过氧化物酶样活性，而相反，通过相同肽和 POM 组分的离子自组装获得的纳米颗粒的催化活性几乎消失。此外，POMlymer 纳米颗粒还对皮肤细菌表现出抗菌和抗生物膜活性；而离子 POM-肽杂化物则显著增加生物膜的产生和内源性活性氧的产生。总之，我们展示了 POMlymer 杂化物自组装成纳米颗粒，并结合过氧化物酶活性和微生物学测定，表明 POM-肽共价键对于自组装纳米颗粒的稳定性以及它们的催化和生物活性是必不可少的。
