Development and Evaluation of Bioinspired Silver Nanoparticles (AgNPs) Synthesized Using Bacillus licheniformis for Wound Healing Applications.

Abstract

Background: Bioinspired nanotechnology offers a sustainable approach to developing advanced therapeutic systems with improved safety and efficacy. Bacillus licheniformis, a non-pathogenic microorganism, has emerged as an efficient biological platform for the eco-friendly synthesis of nanoparticles with biomedical potential.

Objective: This study aimed to develop, optimize, and characterize B. licheniformis–mediated silver nanoparticles (AgNPs) for wound healing applications using a Quality by Design (QbD) framework.

Methods: AgNPs were synthesized using bacterial supernatant and silver nitrate, with process parameters optimized via Central Composite Design (CCD). Physicochemical properties—including particle size, zeta potential, and entrapment efficiency—were evaluated using UV–Vis, FTIR, and SEM analyses. In vitro cytotoxicity, fibroblast migration (scratch assay), and antibacterial assays were conducted to assess biological performance.

Results: The optimized formulation (PF6) exhibited a mean particle size of 38.27 nm, zeta potential of −27.2 mV, and entrapment efficiency of 92.14%. UV–Vis and FTIR confirmed nanoparticle formation and bio-capping by microbial biomolecules, while SEM revealed spherical morphology. PF6 showed excellent stability across varied storage conditions and demonstrated dose-dependent cytocompatibility (IC₅₀ = 35.63 µL/mL). Wound-healing assays revealed 58.5% fibroblast migration at 50 µg/mL, comparable to PDGF (67.8%). Moreover, PF6 exhibited notable antibacterial activity against E. coli (18.81 mm) and S. aureus (18.77 mm).

Conclusion: The study establishes B. licheniformis as a sustainable “green nanofactory” for synthesizing stable, biocompatible AgNPs with potent wound-healing and antimicrobial efficacy. These findings highlight the promise of microbial nanotechnology as a next-generation platform for regenerative medicine.