Biogenic synthesis of nano-sulfur using Punica granatum fruit peel extract with enhanced antimicrobial activities for accelerating wound healing

Microbial wound infections leading to secondary complications in wound healing has resulted in high demand for therapeutic drugs with improved efficacy. Despite achieving enhanced bio-activity and higher bioavailability compared to its bulk form, nano-sulfur (SNP) has been explored to a very limited extent for wound healing applications. In this work, we prepare biogenic SNP (SNP-B) via simple biogenic technique using pomegranate (Punica granatum) peel extract and demonstrate its antimicrobial and wound healing activity. The SNP-B was characterized using powder x-ray diffractometer, FESEM, transmission electron microscopy and Raman spectroscopy. Different wound models (excision, incision, dead space and burn) were used to assess the wound healing potential of SNP-B. The 2% (w/w) SNP-B treated group exhibited enhanced wound contraction rate (excision wound, 99.62 ± 0.59%; burn wound, 99.46 ± 0.59%), breaking strength (393.2 ± 10.87 g cm−2), and granulation tissue weight (166.8 ± 9.45 mg) compared to the control group (excision wound, 84.24 ± 2.78%; burn wound, 90.58 ± 3.2%; breaking strength, 241.3 ± 16.11 g cm−2; granulation tissue weight, 91.17 ± 7.28 mg). The efficacy of 2% (w/w) SNP-B was comparable to that of standard (5% w/w povidone-iodine ointment) in all the wound models analyzed. The SNP-B showed enhanced antibacterial activity with a MIC value of 90, 80, 80, and 60 μg ml−1 for Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus aureus, respectively. The results obtained prove the potential of SNP-B as a multifunctional therapeutic agent for topical applications.