Bovine serum albumin-chitosan nanoparticles loaded with Cordyceps militaris extract: A novel approach to combat MDR bacteria.

The application of Bovine Serum Albumin (BSA) nanoparticles in the medical field has gained substantial attention due to their biocompatibility and multifunctionality as drug delivery systems. Cordyceps militaris, known for its exceptional therapeutic properties, shows promise as a potent agent against multidrug-resistant (MDR) bacteria. This study aimed to develop Cordyceps militaris extract-loaded BSA-chitosan nanoparticles (BECNPs) and cordycepin loaded BSA-chitosan nanoparticles (BCCNPs) to address MDR bacterial infections. BSA nanoparticles were synthesized and characterized using microscopic analyses revealed spherical nanoparticles with an average size of ∼12 nm for BECNPs and ∼28 nm for BCCNPs. GC-MS analysis of the 50 % methanol extract of Cordyceps militaris identified 47 active compounds, with cordycepin (5.22 %) being the major bioactive component. LC-MS confirmed the presence of cordycepin, recognized mainly for its anti-tumor activity, in the extract. The CME and cordycepin loading efficiency were found to be 52.56 % and 62.07 % respectively and the zeta potential of BECNPs and BCCNPs was recorded at +21.45 ± 1.45 and +23.59 ± 1.93 respectively. The antimicrobial activity of BECNPs and BCCNPs was evaluated against two MDR Gram-positive bacteria (Staphylococcus epidermidis and Enterococcus faecalis) and two Gram-negative bacteria (Acinetobacter baumannii and Enterobacter cloacae). MIC, MBC, and zone of inhibition assays demonstrated effective antibacterial activity, with the highest inhibition zone (19.7 ± 0.38 mm) observed for E. cloacae. Additionally, biofilm inhibition and growth curve assays revealed significant disruption of biofilm formation and bacterial growth dynamics. These results highlight the potential of Cordyceps militaris extract-loaded BSA-chitosan nanoparticles as innovative antimicrobial agents and versatile drug delivery systems for biomedical application.