Antimicrobial Hyaluronic Acid/Poly(amidoamine) Dendrimer Multilayer on Poly(3-hydroxybutyrate-<i>co</i>-4-hydroxybutyrate) Prepared by a Layer-by-Layer Self-Assembly Method

In this article, we prepared hyaluronic acid/poly­(amidoamine) dendrimer (HA/PAMAM) multilayers on a poly­(3-hydroxybutyrate-<i>co</i>-4-hydroxybutyrate) [P­(3HB-4HB)] substrate by a layer-by-layer self-assembly method for antimicrobial biomaterials. The results of ζ potential and quartz crystal microbalance with dissipation (QCM-D) showed that HA/PAMAM multilayers could be formed on the substrate layer by layer. We used QCM-D to show that both the HA outer layer and the PAMAM outer layer exhibited good protein-resistant activity to bovine serum albumin and bacterial antiadhesion activity to <i>Escherichia coli</i>. By a live/dead assay and the colony counting method, we found that the PAMAM outer layer could also exhibit bactericidal activity against <i>E. coli</i>, while the HA outer layer had no bactericidal activity. Both the bacterial antiadhesion activity and the bactericidal activity of the samples could be maintained even after storage in phosphate-buffered saline for up to 14 days. An in vitro MTT assay showed that the multilayers had no cytotoxicity to L929 cells, and HA molecules in the multilayers could improve the biocompatibility of the film