Antimicrobial Activity, Stability and Wound Healing Performances of Chitosan Nanoparticles Loaded Recombinant LL37 Antimicrobial Peptide

• DOI: 10.1007/s10989-021-10268-y
• Publication Date: 2021-08-09T16:45:04Z
• Authors: Shohreh Fahimirad; Ehsanollah Ghazna...; Hamid Abtahi; Nahid Sarlak
• Keywords: 0301 basic medicine; 03 medical and health sciences

Antimicrobial peptides have illustrated potent abilities in the elimination of several pathogens resistant to conventional antimicrobial therapeutic agents. LL37 is a well-known human-originated antimicrobial peptide with significant antibacterial activities. Chitosan is considered as an antimicrobial and biodegradable polymer with various therapeutic applications. This study aimed to produce recombinant LL37 loaded into chitosan nanoparticles (CSNPs). So, the synthetic gene of LL37 was cloned into the pET32a expression vector and E. coli BL21 was used as expression host. The antimicrobial performance of the produced recombinant LL37 was analyzed using minimum inhibitory concentration test. Chitosan-LL37 nanoparticles (CSLL37NPs) and blank CSNPs were prepared through the ionic gelation method with TPP crosslinking. The DLS and FE-SEM results confirmed the preparation of spherical CSLL37NPs with an average size of 127.12 nm. The encapsulation efficiency was 78.52%. The encapsulation improved the peptide antimicrobial activity and enhanced stability under thermal, salts, and acidic pH treatments. The more efficient effects of CSLL37NPs on the wound healing progress and elimination of MRSA infection were proved by in vivo assay. Thus, nano-encapsulation of LL37 by chitosan exacerbates its antimicrobial effects and significantly improves the wound-healing capabilities of free LL37.