Hypoxia Preconditioned Serum (HPS)-Hydrogel Can Accelerate Dermal Wound Healing in Mice—An In Vivo Pilot Study

The ability to use the body’s resources to promote wound repair is increasingly becoming an interesting area of regenerative medicine research. Here, we tested the effect of topical application of blood-derived hypoxia preconditioned serum (HPS) on wound healing in a murine wound model. Alginate hydrogels loaded with two different HPS concentrations (10 and 40%) were applied topically on full-thickness wounds created on the back of immunocompromised mice. We achieved a significant dose-dependent wound area reduction after 5 days in HPS-treated groups compared with no treatment (NT). On average, both HPS-10% and HPS-40% -treated wounds healed 1.4 days faster than NT. Healed tissue samples were investigated on post-operative day 15 (POD 15) by immunohistology and showed an increase in lymphatic vessels (LYVE-1) up to 45% with HPS-40% application, while at this stage, vascularization (CD31) was comparable in the HPS-treated and NT groups. Furthermore, the expression of proliferation marker Ki67 was greater on POD 15 in the NT-group compared to HPS-treated groups, in accordance with the earlier completion of wound healing observed in the latter. Collagen deposition was similar in all groups, indicating lack of scar tissue hypertrophy as a result of HPS-hydrogel treatment. These findings show that topical HPS application is safe and can accelerate dermal wound healing in mice.

The Arsenal of Bioactive Molecules in the Skin Secretion of Urodele Amphibians

Urodele amphibians (∼768 spp.), salamanders and newts, are a rich source of molecules with bioactive properties, especially those isolated from their skin secretions. These include pharmacological attributes, such as antimicrobial, antioxidant, vasoactive, immune system modulation, and dermal wound healing activities. Considering the high demand for new compounds to guide the discovery of new drugs to treat conventional and novel diseases, this review summarizes the characteristics of molecules identified in the skin of urodele amphibians. We describe urodele-derived peptides and alkaloids, with emphasis on their biological activities, which can be considered new scaffolds for the pharmaceutical industry. Although much more attention has been given to anurans, bioactive molecules produced by urodeles have the potential to be used for biotechnological purposes and stand as viable alternatives for the development of therapeutic agents.

Experimental Evaluation of an Antimicrobial Protein from Bacillus Amyloliquefaciens MBL27 for Wound Healing Potential in Rats

Objective: This study was aimed at assessing the ability of the antimicrobial protein (AMP) produced by Bacillus amyloliquefaciens MBL27 as a potent wound healant. Methods: Rat models were used to study the efficacy of AMP and AMP incorporated chitosan sheet along with control groups.Results: AMP and AMP incorporated chitosan sheet significantly improved wound contraction when compared to controls. Rate of wound contraction (97.23%), decreased period of epithelialization (14 days) and the levels of biochemical markers such as hydroxyproline (collagen), hexosamine, uronic acid and total protein in the granulation tissue on various days of wound healing revealed the wound healing efficacy of the AMP. The histological examinations also correlated well with the biochemical findings, confirming the wound healing efficacy of the AMP. Conclusion: The results indicate the beneficial effects of AMP from B.amyloliquefaciens MBL27 and its potential to be developed into new therapeutic agent for dermal wound healing.

Immunologic Roles of Hyaluronan in Dermal Wound Healing

Hyaluronic acid (HA), a glycosaminoglycan ubiquitous in the skin, has come into the limelight in recent years for its role in facilitating dermal wound healing. Specifically, HA’s length of linearly repeating disaccharides—in other words, its molecular weight (MW)—determines its effects. High molecular weight (HMW)-HA serves an immunosuppressive and anti-inflammatory role, whereas low molecular weight (LMW)-HA contributes to immunostimulation and thus inflammation. During the inflammatory stage of tissue repair, direct and indirect interactions between HA and the innate and adaptive immune systems are of particular interest for their long-lasting impact on wound repair. This review seeks to synthesize the literature on wound healing with a focus on HA’s involvement in the immune subsystems.

Effect of Pulsed 810 nm Laser Photobiomodulation on Dermal Wound Healing and Oxidative Stress in Immunosuppressed Rats

Under immunosuppression, the sequential overlapping wound repair phases get hampered due to dysregulated or persistent inflammation leading to non-healing chronic wounds formation. The present study investigates the effect of low-power 810 nm diode laser (70 mW mean output power; 40 mW/cm2 average irradiance; 24 J/cm2 total fluence; 10 Hz pulse frequency; duty cycle 50 per cent; 10 min. illumination time once daily for seven days) photobiomodulation (PBM) on dermal penetration ability, wound healing and oxidative stress in hydrocortisone-induced immunosuppressed rats. The results of the penetration ability of 810 nm laser irradiation to the depth of the sub-dermal region revealed that the transmitted power of laser at 10 Hz pulsed-mode was better and easier than continuous-mode. The present findings clearly delineated that PBM with 810 nm laser at 10 Hz significantly augmented healing and reduced oxidative stress as evidenced by decreased free radicals, nitric oxide (NO) levels, enhanced superoxide dismutase (SOD) enzyme activity and wound area contraction facilitating the cellular redox homeostasis and promoting the tissue repair process. In conclusion, PBM with NIR 810 nm laser at pulsed-mode 10 Hz frequency showed better penetration and accelerated dermal wound healing in immunosuppressed rats.