The effect of different topical agents (silver sulfadiazine, povidone-iodine, and sodium chloride 0.9%) on burn injuries in rats

Wound healing in second-degree burns in rats treated with silver sulfadiazine: a systematic review and meta-analysis

Objective:

This study aims to assess the wound healing efficacy in second-degree burns in rats treated with 1% silver sulfadiazine (SSD)—a sulfonamide antibiotic.

Method:

This is a systematic literature review and meta-analysis performed according to the PICO (Population, Intervention, Comparison and Outcomes) strategy.

Results:

The review found 100 studies in PubMed, Web of Science and other search engines. Of these, 70 studies were pre-selected after removing duplicates. After independent analysis by two reviewers, only seven studies met the inclusion criteria for meta-analysis. All studies except one showed faster wound closure by the application of silver sulfadiazine ointment. Using a random effects model, healing was faster in SSD-treated groups when compared to the control group on day 21, with a statistically significant mean difference of –2.72 days (95% confidence interval: –4.99, –0.45) between treatment and control groups (p<0.01).

Conclusion:

The results of this meta-analysis revealed that SSD aided in faster healing of second-degree burns.

Topical delivery of chitosan-capped silver nanoparticles speeds up healing in burn wounds: A preclinical study

This study investigated the effects of topical application of chitosan-capped silver nanoparticles (Ch/AgNPs) on burn wound healing. The chitosan-capped silver nanoparticles were synthesized in one step from the silver nitrate, sodium borohydride, and chitosan and were characterized using transmission electron microscopy, fourier transform infrared spectroscopy, and X-ray diffraction methods. The antioxidant assay was performed to evaluate the scavenging rate. The effects of Ch/AgNPs on burn wound healing was also evaluated by histopathological, molecular, and biochemical evaluations after 7, 14 and 28 days of treatment in a rat model. In comparison to the negative control and silver sulfadiazine groups, the Ch/AgNPs treated wounds exhibited significantly lower inflammatory reaction as determined by the reduced level of interleukin-1β (IL-1β) and neutrophil counts. Treatment by Ch/AgNPs also significantly enhanced re-epithelialization, so that complete epithelialization was achieved in the lesions of the animals of this group, at the 7th day post-wounding. Rapid re-epithelialization, improved granulation tissue formation, reduced IL-1β expression, mild inflammation, and increased transforming growth factor-β1 and basic fibroblast growth factor, at 7 days post-wounding, are convincing reasons to confirm this idea that Ch/AgNPs are effective in speeding up the wound healing stages. Our histopathological findings are in agreement with the molecular and biochemical results and strongly demonstrate that Ch/AgNPs stimulate burn wound healing by decreasing the length of repair phases. Therefore, on the basis of our findings, Ch/AgNPs can be a promising candidate in stimulating wound repair and regeneration.

Nanomedicine and advanced technologies for burns: Preventing infection and facilitating wound healing

According to the latest report from the World Health Organization, an estimated 265,000 deaths still occur every year as a direct result of burn injuries. A widespread range of these deaths induced by burn wound happens in low- and middle-income countries, where survivors face a lifetime of morbidity. Most of the deaths occur due to infections when a high percentage of the external regions of the body area is affected. Microbial nutrient availability, skin barrier disruption, and vascular supply destruction in burn injuries as well as systemic immunosuppression are important parameters that cause burns to be susceptible to infections. Topical antimicrobials and dressings are generally employed to inhibit burn infections followed by a burn wound therapy, because systemic antibiotics have problems in reaching the infected site, coupled with increasing microbial drug resistance. Nanotechnology has provided a range of molecular designed nanostructures (NS) that can be used in both therapeutic and diagnostic applications in burns. These NSs can be divided into organic and non-organic (such as polymeric nanoparticles (NPs) and silver NPs, respectively), and many have been designed to display multifunctional activity. The present review covers the physiology of skin, burn classification, burn wound pathogenesis, animal models of burn wound infection, and various topical therapeutic approaches designed to combat infection and stimulate healing. These include biological based approaches (e.g. immune-based antimicrobial molecules, therapeutic microorganisms, antimicrobial agents, etc.), antimicrobial photo- and ultrasound-therapy, as well as nanotechnology-based wound healing approaches as a revolutionizing area. Thus, we focus on organic and non-organic NSs designed to deliver growth factors to burned skin, and scaffolds, dressings, etc. for exogenous stem cells to aid skin regeneration. Eventually, recent breakthroughs and technologies with substantial potentials in tissue regeneration and skin wound therapy (that are as the basis of burn wound therapies) are briefly taken into consideration including 3D-printing, cell-imprinted substrates, nano-architectured surfaces, and novel gene-editing tools such as CRISPR-Cas.

Evaluation of a polyurethane foam dressing impregnated with 3% povidone-iodine (Betafoam) in a rat wound model

Purpose

The purpose of this study was to evaluate the efficacy of Betafoam in terms of wound healing and safety.

Methods

Fifty-four male adult Sprague-Dawley rats (weight, 200–250 g) were used in the study. Full-thickness skin defects were created on the back of each rats. The rats were assigned to 6 groups according to the type of wound dressing used (n = 9 for each group): Betafoam, Allevyn-Ag, Mepilex-Ag, Medifoam silver, Polymem-Ag, and gauze. The wound size, histological findings, and amount of DNA on the changed dressings for each group were analyzed and compared.

Results

All groups showed an effective decrease in wound size. However, the differences between Betafoam and the other dressings were statistically significant on day 14 (P < 0.05). The number of newly generated blood vessels in the Betafoam group was significantly higher than in the gauze, Allevyn-Ag, and Medifoam silver groups (P < 0.001). In the Betafoam group, the proportion of collagen deposition was highest and showed a significantly superior arrangement of collagen fibers compared with the gauze, Allevyn-Ag, Mepilex-Ag, and Medifoam silver groups. The total content of the remaining DNA counts of the exchanged dressings were significantly lower in the Betafoam group than the others.

Conclusion

Betafoam is effective in wound healing and provides the best performance amongst the various types of dressing materials in terms of re-epithelialization, angiogenesis, collagen deposition, and tissue invasion.

Coconut Shell Liquid Smoke Promotes Burn Wound Healing

The aim of this study was to evaluate burn wound healing activity of coconut shell liquid smoke (CS-LS) in a burn wound animal model. Burn wound–induced mice were treated with CS-LS (CS-LS group), povidone iodine 10% (povidone group), or NaCl 0.9% (NaCl group). Application of CS-LS promoted wound contraction compared to that of the povidone and NaCl groups (P < .05). This study showed a positive correlation between the number of fibroblasts and wound contraction. The number of fibroblasts was highest in the CS-LS group, compared to that of the povidone and NaCl groups (P < .05). In conclusion, CS-LS promotes burn wound healing by one possible mechanism, by increasing the number of fibroblasts. The results indicate that further experimental trials are needed to develop CS-LS as an alternative topical drug for burn wound healing.

Photo-biomodulatory response of low-power laser irradiation on burn tissue repair in mice

The present work reports the photo-biomodulatory effect of red (632.8 nm) and near infrared (785 and 830 nm) lasers on burn injury in Swiss albino mice. Animals were induced with a 15-mm full thickness burn injury and irradiated with various fluences (1, 2, 3, 4, and 6 J/cm²) of each laser wavelength under study having a constant fluence rate (8.49 mW/cm²). The size of the injury following treatment was monitored by capturing the wound images at regular time intervals until complete healing. Morphometric assessment indicated that the group treated with 3-J/cm² fluence of 830 nm had a profound effect on healing as compared to untreated controls and various fluences of other wavelengths under study. Histopathological assessment of wound repair on treatment with an optimum fluence (3 J/cm²) of 830 nm performed on days 2, 6, 12, and 18 post-wounding resulted in enhanced wound repair with migration of fibroblasts, deposition of collagen, and neovascularization as compared to untreated controls. The findings of the present study have clearly demonstrated that a single exposure of 3-J/cm² fluence at 830-nm enhanced burn wound healing progression in mice, which is equivalent to 5 % povidone iodine treatment (reference standard), applied on a daily basis till complete healing.