The dual role of bio-inspired palladium nanoparticles in antibacterial action and wound healing: An <i>in vitro</i> and <i>in vivo</i> study

Nanoparticles have become essential in theragnostic applications due to their multi-functionality. However, conventionally synthesized nanoparticles are often limited by high production costs and moderate efficacy. To address these challenges, this study focuses on bio-inspired palladium nanoparticles (PdNPs), an entirely novel nanomaterial synthesized with the Plectranthus amboinicus leaf extract offering an economical, green, biocompatible, and stable substitute. To characterize biosynthesized PdNPs, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-Vis spectroscopy, energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (TEM), and zeta potential analysis were employed. The nanoparticles, measuring 5–40 nm, displayed diverse shapes (spherical, triangular, and rectangular), with XRD revealing a face-centered cubic (fcc) crystalline structure. The zeta potential value of -12.9 mV indicated high stability due to the surface charge of the PdNPs. Therapeutically, PdNPs exhibited broad-spectrum antibacterial activity, particularly against E. coli (14 ± 0.3 mm inhibition zone), along with potent antioxidants (71.41 ± 0.94%), anti-diabetic (77%), and anti-inflammatory (72%) properties. Remarkably, PdNPs-based ointments in a mouse excision wound model demonstrated a 74.76% wound closure within 10 days in a mouse model, with complete healing achieved by day 14. This study therefore underscores the broad applicability of PdNPs emphasizing its novelty and potential as a competitive alternative to conventional therapies making it ideal for numerous biomedical applications such as wound healing, tissue repair, dentistry, regenerative medicine, and biosensing platforms.