Wound Healing Of Skin Defects Research Articles

Application of collagen-chondroitin sulfate scaffolds with different pore sizes combined with acidic fibroblast growth factor in repairing full thickness skin defects in nude mice

Wound healing of skin defects is complex. For the treatment of large and deep wounds, it is a good alternative to accept artificial dermis grafting at the first stage surgery, and autologous split-thickness skin grafting 2–3 weeks later at the second stage surgery. In addition, the effectiveness of numerous cytokines such as fibroblast growth factor (FGF) on wounds healing has been widely researched. The traditional view is that direct external application or in vivo injection of exogenous FGFs may not achieve the desired therapeutic effect as the effective concentration cannot be maintained for a long time. Therefore, some researchers have tried to integrate various cytokines into skin substitutes for combined application. However, we believe that considering the current situation, it is still difficult to achieve mass production of these types of artificial dermis. Here, we manufactured a collagen-chondroitin sulfate scaffold material by imitating the marketed artificial dermis materials. Then, we combined it with recombinant human acidic FGF in a single full dose during the first-stage artificial dermis transplantation, which is simple and completely feasible but always controversial in the current clinical work, to explore whether this combinatorial therapy could serve as an efficient way wound healing in the Balb/c-nu mice full-thickness skin defect model.

Antibacterial Cellulose Nanocrystal-Incorporated Hydrogels With Satisfactory Vascularization for Enhancing Skin Regeneration.

Wound healing of skin defects remains a significant clinical problem due to inflammation, infection, and dysangiogenesis; especially, the promotion of microvasculature formation in healing of chronic wound or deep skin defects is critical as it supplies oxygen and nutrients to the impaired tissue, relieving uncontrolled inflammatory responses. The cellulose nanocrystals (CNCs) in the liquid crystalline phase, which facilitates cell proliferation and migration, has been shown to improve vascularization effectively. Therefore, we developed a novel injectable hydrogel based on Schiff base and coordination of catechol and Ag. The obtained hydrogels (CCS/CCHO-Ag) exhibited in situ forming properties, satisfactory mechanical performance, controlled release of Ag, antibacterial capacity, and biocompatibility. In addition, the hydrogels could also entirely cover and firmly attach wounds with irregular shapes, so as to reduce the re-injury rate. More importantly, experiments in vitro and in vivo demonstrated that CCS/CCHO-Ag hydrogels can promote neovascularization and tissue regeneration, thanks to their anti-inflammatory and antibacterial effects. In conclusion, these multifunctional hydrogels are well on the way to becoming competitive biomedical dressings, which show tremendous potential application in the field of tissue engineering.

Evaluation of wound healing of skin defect in mice with radiation injury

Objective To establish mouse models of total body irradiation(TBI) with different doses of 60Co γ radiation combined with skin defect,so as to investigate the influence of TBI on wound healing and the pathophysiological changes in combined radiation injury and skin defect.Methods A total of 180 female Kunming mice were irradiated with a single dose of 4,6 or 8 Gy 60Co γ ray.Within 30 min after irradiation,a full thickness square wounds(1.5 cm×1.5 cm) was made on the back of mice to establish animal models of TBI combined with skin defect(n=50),another 30 mice with pure skin defect were used as controls(n=30).Mice in each group were sacrificed on the 3rd,5th,7th,10th and 14th day after injury,each time 6 mice,and the full thickness wounds were harvested.Histological method was used to evaluate the changes of inflammatory cells,fibroblasts and new blood capillaries in the wounds.Image analysis system was used to analyze the areas of the residual wounds.The survival rates and body weight changes of mice within 14 days were analyzed in all groups.Results On the 7th and 14th day after injury,the survival rates of mice in the 6 Gy group were 75% and 55%,respectively.While in the 8 Gy group the survival rate of mice was only 33% on the 7th day,and all the animals died by the 10th day.Within 14 days after injury,the body weight loss of mice demonstrated an increasing tendency with the increase of radiation doses(4,6,and 8 Gy groups).TBI delayed wound healing in mice with the increase of irradiation dose.The unhealed areas in the 6 and 8 Gy groups were larger than that in the control group on the 2nd day(P0.01),and that in 4 Gy group was significantly larger than that in the control group on the 8th day(P0.05).H-E staining showed that the early inflammatory responses were inhibited,the increase of fibroblasts and new capillaries were greatly delayed,and the granulation tissue formation and reepithelialization were slowed down in the TBI group compared with the simple wound group.Conclusion Animal models of TBI with 6 Gy 60Co γ-ray combined with skin defect can serve as a platform to study the mechanism of difficult healing and early treatment of radiation injury combined with skin defect.