Impact of acacia arabica topical gel on skin wound healing: An experimental study

Aim of the study: To estimate the influence of Acacia Arabica gel abstract on skin wound healing. Material and method: 28male adult rabbits were included, 2 incisions of 1cm length were made on the skin of the rabbit’s back, one is treated by acacia gel while another left for normal healing, histopathological examination was done at 24h, 3, 7 and 14 days intervals. Results: The inflammatory reactions showed no significant results for both the control group and the study group during the study intervals. Granulation tissue in the control group was absent after 24h but increased to become profound after 7 days then become moderate, while the study group showed scanty granulation tissue from the first day and increased through study intervals. Re-epithelialization mean scores in the study group were higher than control one. Conclusions: Acacia arabica has the efficacy of hastening the wound healing process.

Skin wound healing assessment via an optimized wound array model in miniature pigs

An appropriate animal wound model is urgently needed to assess wound dressings, cell therapies, and pharmaceutical agents. Minipig was selected owing to similarities with humans in body size, weight, and physiological status. Different wound sizes (0.07–100 cm2) were created at varying distances but fail to adequately distinguish the efficacy of various interventions. We aimed to resolve potential drawbacks by developing a systematic wound healing system. No significant variations in dorsal wound closure and contraction were observed within the thoracolumbar region between boundaries of both armpits and the paravertebral region above rib tips; therefore, Lanyu pigs appear suitable for constructing a reliable dorsal wound array. Blood flow signals interfered with inter-wound distances ˂ 4 cm; a distance > 4 cm is therefore recommended. Wound sizes ≥ 4 cm × 4 cm allowed optimal differentiation of interventions. Partial- (0.23 cm) and full-thickness (0.6 cm) wounds showed complete re-epithelialization on days 13 and 18 and strongest blood flow signals at days 4 and 11, respectively. Given histological and tensile strength assessments, tissue healing resembling normal skin was observed at least after 6 months. We established some golden standards for minimum wound size and distance between adjacent wounds for effectively differentiating interventions in considering 3R principles.

Immunomodulation of Skin Repair: Cell-Based Therapeutic Strategies for Skin Replacement (A Comprehensive Review)

The immune system has a crucial role in skin wound healing and the application of specific cell-laden immunomodulating biomaterials emerged as a possible treatment option to drive skin tissue regeneration. Cell-laden tissue-engineered skin substitutes have the ability to activate immune pathways, even in the absence of other immune-stimulating signals. In particular, mesenchymal stem cells with their immunomodulatory properties can create a specific immune microenvironment to reduce inflammation, scarring, and support skin regeneration. This review presents an overview of current wound care techniques including skin tissue engineering and biomaterials as a novel and promising approach. We highlight the plasticity and different roles of immune cells, in particular macrophages during various stages of skin wound healing. These aspects are pivotal to promote the regeneration of nonhealing wounds such as ulcers in diabetic patients. We believe that a better understanding of the intrinsic immunomodulatory features of stem cells in implantable skin substitutes will lead to new translational opportunities. This, in turn, will improve skin tissue engineering and regenerative medicine applications.

Preliminary Study on Human Adipose Stem Cells Promoting Skin Wound Healing Through Notch1 Signaling Pathway

Background: Mesenchymal stem cells (MSCs) have been documented as possible candidates for wound healing treatment because their use could reinforce the regenerative capacity of many tissues. Human adipose stem cells (hADSCs) have the advantages of easy access, large quantity and easy operation. They can be fully applied in the treatment of skin wounds. In this study, we aim to explore the roles and potential mechanisms of hADSCs in cutaneous wound healing.Methods: hADSCs were obtained from human subcutaneous fat. Adipocytes and osteocytes differentiated from hADSCs were determined by staining with Oil Red O and alkaline phosphatase (ALP), respectively. We assessed the effects of hADSCs and hADSC conditional medium (CM) on wound healing in an injury model of mice. Than, we investigated the biological effects of hADSCs on human keratinocytes HaCAT cells in vitro.Results: The results showed that hADSCs could be successfully differentiated into osteogenic and lipogenic cells. hADSCs and hADSCs-CM significantly promote skin wound healing in vivo. hADSCs significantly promoted HaCAT cells proliferation and migration through activating Notch1 signaling pathway, and activated the AKT signaling pathway by Rps6kb1 kinase in HaCAT cells. In addition, we found that hADSCs-mediated activation of Rps6kb1/AKT signaling was dependent on the Notch1 signaling pathway.Conclusion: We demonstrated that hADSCs can promote skin cell-HaCAT cells proliferation and migration via Notch1 pathway, suggesting that hADSCs may provide an alternative therapeutic approach for the treatment of skin injury.

Large full-thickness wounded skin regeneration using 3D-printed elastic scaffold with minimal functional unit of skin

Traditional tissue engineering skin are composed of living cells and natural or synthetic scaffold. Besize the time delay and the risk of contamination involved with cell culture, the lack of autologous cell source and the persistence of allogeneic cells in heterologous grafts have limited its application. This study shows a novel tissue engineering functional skin by carrying minimal functional unit of skin (MFUS) in 3D-printed polylactide-co-caprolactone (PLCL) scaffold and collagen gel (PLCL + Col + MFUS). MFUS is full-layer micro skin harvested from rat autologous tail skin. 3D-printed PLCL elastic scaffold has the similar mechanical properties with rat skin which provides a suitable environment for MFUS growing and enhances the skin wound healing. Four large full-thickness skin defects with 30 mm diameter of each wound are created in rat dorsal skin, and treated either with tissue engineering functional skin (PLCL + Col + MFUS), or with 3D-printed PLCL scaffold and collagen gel (PLCL + Col), or with micro skin islands only (Micro skin), or without treatment (Normal healing). The wound treated with PLCL + Col + MFUS heales much faster than the other three groups as evidenced by the fibroblasts migration from fascia to the gap between the MFUS dermis layer, and functional skin with hair follicles and sebaceous gland has been regenerated. The PLCL + Col treated wound heals faster than normal healing wound, but no skin appendages formed in PLCL + Col-treated wound. The wound treated with micro skin islands heals slower than the wounds treated either with tissue engineering skin (PLCL + Col + MFUS) or with PLCL + Col gel. Our results provide a new strategy to use autologous MFUS instead “seed cells” as the bio-resource of engineering skin for large full-thickness skin wound healing.