Autor(es): Alves, PM ; Pereira, RF ; Costa, B ; Tassi, N ; Teixeira, C ; Leiro, V ; Monteiro, C ; Gomes, P ; Costa, F ; Martins, MCL
Data: 2022
Identificador Persistente: https://hdl.handle.net/10216/142702
Origem: Repositório Aberto da Universidade do Porto
Assunto(s): Peptidopolysaccharides; Surface modification; Covalent conjugation; Thiol-ene; Peptide tethering; Dhvar5
Covalent conjugation of antimicrobial peptides (AMP) is considered an effective approach to overcome their potential degradation in vivo. As the high cost of AMP-based therapies is one of the major hurdles towards their clinical application, it is urgently needed to explore high yield reactions. Herein, the highly efficient thiol-norbornene photoclick chemistry (TNPC) was explored for AMP grafting onto chitosan. Norbornenes were introduced onto chitosan (NorChit) in an aqueous/organic system, followed by UV-triggered conjugation of N- and C-terminus cysteine-modified Dhvar5 (NorChit-Dhvar5). Up to 0.38 norbornene groups per chitosan repeating unit and up to 43% conjugation yield in NorChit-Nt-Dhvar5 (80 μmol of Dhvar5/g) were achieved, while in NorChit-Ct-Dhvar5 conjugation yield was 30% (55 μmol of Dhvar5/g). Finally, NorChitDhvar5 ultrathin films showed up to a 35% reduction of total adhered Gram-positive Staphylococcus epidermidis and increased the adhesion and killing of Gram-negative Pseudomonas aeruginosa compared to unmodified chitosan. Moreover, NorChit-Dhvar5 was noncytotoxic to human neonatal dermal fibroblasts, according to ISO 10993-1. Overall, our findings indicate TNPC as a high yield strategy for AMP grafting onto norbornene-functionalized biopolymers towards the fabrication of antibacterial biomaterials.
