# Photobiomodulation and Sericin in the Treatment of Second‐Degree Burns Induced in Wistar Rats

## TL;DR

This study tested how sericin and laser therapy help heal burns in rats, finding that combining them improves tissue repair and reduces inflammation.

## Contribution

The study introduces the combined use of sericin and photobiomodulation for burn healing, showing enhanced collagen and reduced oxidative stress.

## Key findings

- SER + PBM treatment showed the highest type I collagen scores and outperformed other treatments.
- Groups with PBM had reduced oxidative stress markers like TNF-alpha and thiobarbituric acid reactive substances.
- Collagen scores were significantly higher in SER, PBM, SUL + PBM, and SER + PBM groups compared to controls.

## Abstract

This study investigated the isolated and combined effects of sericin and low‐level laser photobiomodulation (PBM) on the healing of experimentally induced second‐degree burns in male Wistar rats. Sericin has previously been associated with enhanced fibroblast migration and improved reepithelialization, while PBM has shown anti‐inflammatory potential. To assess their therapeutic value, 60 rats were randomised into six groups: untreated control (CON), silver sulfadiazine (SUL), sericin cream (SER), PBM alone, SUL + PBM and SER + PBM. Burn injuries were produced using a heated metal instrument applied for 3 s, and animals were euthanized 14 days later. Macroscopic photography, photothermography and histomorphometric analyses were performed. Statistical tests using generalised linear models were set at p = 0.05. A significant temperature difference between initial (AV0) and follow‐up (AV1) evaluations was observed, although granulation tissue formation did not differ across groups. Collagen analysis revealed that SER, PBM, SUL + PBM and SER + PBM groups presented higher collagen scores than controls (p < 0.05). The SER + PBM treatment was particularly effective, showing the greatest proportion of type I collagen and statistical superiority over the other interventions (p < 0.05). Molecular evaluations demonstrated reduced levels of tumour necrosis factor alpha, thiobarbituric acid reactive substances and catalase, especially in groups receiving PBM in combination with either sericin or sulfadiazine, suggesting a decrease in oxidative stress. Overall, the results indicate that both sericin and PBM positively influence tissue repair, with combined therapy—particularly SER + PBM—yielding enhanced collagen deposition and biochemical markers consistent with improved healing. Further studies are warranted to clarify the underlying biological mechanisms driving these outcomes.