Healing is a complex process of adult skin damage that requires a synergistic biochemical process for on-site repair. A variety of cell types (macrophages, leukocytes, mast cells) contribute to the relevant stages of proliferation, migration, matrix synthesis and contraction, as well as growth factors and matrix signals at the wound site. Understanding the on-site signal control and cellular activities can help explain the process of adult skin repair, not just repair, more regeneration, assessment of biomechanics and implementation of strategies to accelerate wound healing in regenerative medicine.

Bioengineers, materials scientists and life scientists who study materials and medicine have developed autografts , allografts and xenografts for partial and complete wound healing. Due to the potential risks of antigenicity and disease transmission , the limitations of these procedures can delay the healing of large areas of skin defects and are an important clinical problem in healthcare . Tissue engineering strategies for skin regeneration are a practical approach involving the use of bioactive biomaterials to aid angiogenesis and faster revascularization.
In a recent study, colleagues at Sorin Marza and his interdisciplinary research institutes and physics, bio-nanoscience, pharmacy, and medical schools developed bioactive glass-gold nanoparticles (BG-AuNPs) to promote granulation tissue . Growth and induction of wound healing. In this study, scientists used experimental rat models to study the effects of BG-AuNP composites as topical ointments on skin wound healing for 14 days. Marza et al. A sol-gel BGs and BG-AuNP composite was developed in a mixture with petrolatum at concentrations of 6, 12 and 18% (% by weight) to understand the skin's repair response. Scientists have observed the use of BG-Vaseline ointment to treat granuloma reactions during wound healing. The results have now been published in biomedical materials , published by IOP.

Angiogenesis or the formation of new blood vessels from existing blood vessels is an important process in the process of skin regeneration. Bioactive glass is responsible for local cellular reactions due to in vivo degradation , stimulating the release of growth factors such as VEGF (vascular endothelial growth factor) and bFGF (basic fibroblast growth factor) , thereby causing angiogenesis. Based on the results of in vivo animal models, various tissue engineering studies have demonstrated the benefits of bioactive glass in wound healing . Scientists have reported in their principle of action that bioactive glass stimulates this process by controlling the inflammatory response , thereby enhancing the paracrine effect between macrophages and repair cells.

Gold nanoparticles (AuNPs) also become important in medicine due to their chemical and physical properties of biocompatibility, surface modification, stability and optical properties . Despite their challenging early translation in tissue engineering methods , low concentrations of AuNP can stimulate cell proliferation during wound repair. Previous studies in the same research group have shown that bioactive glass containing AuNPs can stimulate the proliferation of human keratinocytes Cells (HaCaT), which account for 95% to 97% of the epidermis of the skin surface. In this study, Marza et al. The potential of dermal tissue regeneration in vivo was studied. By day 14, they observed that BG and BG-AuNP-Vaseline ointment stimulated complete skin regeneration in experimental rat models, as confirmed by gold standard histopathological analysis.

Marza et al. Freshly prepared spherical AuNPs ranging in size from 15 nm to 30 nm were confirmed to be embedded in the glass matrix using transmission electron microscopy (TEM) micrographs . Using X-ray powder diffraction (XRD) patterns of glass samples , scientists studied amorphous structures to determine the crystal center and gold mark. Characterization studies of composite samples also include Fourier Transform Infrared Spectroscopy (FTIR), which provides a typical spectrum of silicate networks . To develop a glass composition ointment, scientists dispersed the powder composite in petrolatum. They then measured the particle size distribution using dynamic light scattering (DLS) and confirmed the size difference between the BG-Vaseline and BG-AuNP-Vaseline sample structures.

After extensive material characterization, scientists performed biofunctionalization studies in vitro of corneal cell cultures to validate biocompatibility prior to surgery in transformed animal models. As before, Marza et al. The proliferation of HaCaT cells on BG-AuNP was studied and comparable results were obtained for good in vitro tolerance during keratinocyte proliferation on both materials (BG and BG-AuNP). The results confirmed that the composite material can be used as an ointment for in vivo research.

To assess the healing potential of BG and BG-AuNPs in petroleum jelly, Mayer et al. Composites were formed at concentrations of 6, 12 and 18% by weight. For comparison, scientists used petrolatum as a positive control. In the rat model, scientists carefully created four skin-removing wounds by successfully replicating previously published small animal surgical protocols . When applying ointment, they used a specific method for each rat; (1) left upper resection as a control, no ointment, (2) left lower resection, scientists applied BG-Vaseline ointment, (3) upper right resection, they were applied separately When Vaseline and (4) were removed at the lower right, they used BG-AuNP-Vaseline ointment.

Scientists used 30 rats in the study, 10 of which were assigned to different groups (6% BG-Vaseline and BG-AuNPs-Vaseline ointment; 12% BG / BG-AuNPs-Vaseline; 18% BG / BG-AuNPs - Vaseline). The working agreement for each group is the same. After using the ointment, the scientists added a sterile bandage to the wound site of the rat to prevent postoperative wound infection and subcutaneous injection of tramadol as an analgesic. By the 13th day, all animal wounds were closed. Fourteen days later, they humanely euthanized the animals and performed histological examination to reveal mild inflammatory responses and wound healing responses in each animal group. In all groups, vascular proliferation was mild to moderate.

Meyer and others. The intact epidermis in the 18% BG-AuNPs-Vaseline group was observed, and the dermis and skin appendages completely healed. They also observed a lack of vascular proliferation in this group due to late healing and advanced vascular remodeling. In this way, Mayer et al. Widely characterized and established bioactive glass - gold nanoparticle-based Vaseline ointment as a promising material for wound healing. The research team will conduct further research to optimize wound healing ointments for translation from bedside to bedside translation.

Further exploration: cells under the skin explain the difference in healing

More information: SMMârza et al. Skin wound regeneration with bioactive glass-gold nanoparticle ointment, Biomedical Materials (2019). DOI: 10.1088 / 1748-605X / aafd7d

K. Magyari et al. New Bioactive Glass-AuNP Composites for Biomedical Applications , Materials Science and Engineering: C (2017). DOI: 10.1016 / j.msec.2017.03.138

Xu Xusheng and so on. Mouse excision wound splint models, including stem cell transplantation applications, Nature Protocols (2013). DOI: 10.1038 / nprot.2013.002

AC Jayalekshmi et al. Gold nanoparticle-incorporated polymer/bioactive glass composites for controlled drug delivery applications, colloids and surface B: biological interfaces (2014). DOI: 10.1016 / j.colsurfb.2014.12.021