Injectable gelatin/oxidized dextran hydrogel loaded with apocynin for skin tissue regeneration.

Acute skin injury should be treated in time, due to many factors will affect the normal healing process of wounds, hinder tissue regeneration, and eventually form chronic wounds. Herein, an injectable, in-situ gel-forming hydrogel has been fabricated. The hydrogel is stabilized by dynamic Schiff base and composed of gelatin (Gel), oxidized dextran (Odex) and apocynin (Apo). In vitro studies have shown that this hydrogel has good injectability, plasticity, self-healing and efficient hemostatic properties. The hydrogel has good cytocompatibility with HaCaT and L929 cells by the Live/Dead cell staining. Furthermore, in vivo studies have shown that hydrogel loaded with APO can accelerate angiogenesis and skin tissue regeneration by reducing wound inflammation. Therefore, the injectable Gel/Odex/Apo hydrogel has the advantages of simple preparation process, convenient use and multifunction, etc., it is a promising wound dressing for full-thickness skin repair and has great potential in the field of skin tissue regeneration.

Injectable multifunctional CMC/HA-DA hydrogel for repairing skin injury.

Injectable Hydrogels with adhesive, antioxidant and hemostatic properties are highly desired for promoting skin injury repair. In this study, we prepared a multi-functional carboxymethyl chitosan/hyaluronic acid-dopamine (CMC/HA-DA) hydrogel, which can be crosslinked by horseradish peroxidase and hydrogen peroxide. The antioxidation, gelation time, degradability, rheology and antihemorrhagic properties of hydrogels can be finely tuned by varying composition ratio. The cytocompatibility test and hemolysis test confirmed that the designed hydrogel holds good biocompatibility. More importantly, the repair effect of the hydrogel on full-thickness skin injury model in mice was studied. The results of wound healing, collagen deposition, immunohistochemistry and immunofluorescence showed that CMC/HA-DA hydrogel could significantly promote angiogenesis and cell proliferation at the injured site. Notably, the inflammatory response can also be regulated to promote the repair of full-thickness skin defect in mice. Results indicate that this injectable CMC/HA-DA hydrogel holds high application prospect for promising wound healing.

Environmentally responsive hydrogels for repair of cardiovascular tissue.

Cardiovascular diseases (CVDs) pose a serious threat to human health, which are characterized by high disability and mortality rate globally such as myocardial infarction (MI), atherosclerosis, and heart failure. Although stem cells transplantation and growth factors therapy are promising, their low survival rate and loss at the site of injury are major obstacles to this therapy. Recently, the development of hydrogel scaffold materials provides a new way to solve this problem, which have shown the potential to treat CVD. Among these scaffold materials, environmentally responsive hydrogels have great prospects in repairing the microenvironment of cardiovascular tissues and vascular regeneration. They provide a new method for the treatment of cardiovascular tissue repair and space-time control for the release of various therapeutic drugs, including small-molecule drugs, growth factors, and stem cells. Herein, this article reviews the occurrence and current treatment of CVD, as well as the repair of cardiovascular injury by several environmental responsive hydrogels systems currently used, mainly focusing on the delivery of growth factors or the application of cell therapy to revascularization. In addition, we will also discuss the enormous potential and personal perspectives of environmentally responsive hydrogels in cardiovascular repair.

The Development of Hyaluronic Acids Used for Skin Tissue Regeneration.

Burns, mechanical injuries, skin defects, poor wound healing and scars caused by chronic diseases are serious clinical issues that affect millions of people around the world. Hyaluronic acid (HA) is one of the main components of extracellular matrix, which is widely distributed in human body. Because of its unique physical and chemical properties and diversity of physiological functions, hyaluronic acid is widely used in tissue engineering and regenerative medicine. This paper reviews the application of HA and HA based scaffolds in the regeneration and repair of skin tissue, as well as the application of HA in the fields of skin filler, wound healing, beauty, etc.

Aloe vera: A Medicinal Plant Used in Skin Wound Healing.

Skin injury is a major problem threatening human physical and mental health, and how to promote wound healing has been the focus. Developing new wound dressings is an important strategy in skin regeneration. Aloe vera is a medicinal plant with a long history, complex constituents, and various pharmacological activities. Many studies have shown that A. vera plays an important role in promoting wound healing. Adding A. vera to wound dressing has become an ideal way. This review will describe the process of skin injury and wound healing and analyze the role of A. vera in wound healing. In addition, the types of wound dressing and the applications of A. vera in wound dressing will be discussed.

Benlysta-Loaded Sodium Alginate Hydrogel and Its Selective Functions in Promoting Skin Cell Growth and Inhibiting Inflammation.

Benlysta is a new drug approved by the US Food and Drug Administration (US FDA) in 2019 for the treatment of systemic lupus erythematosus. In this study, we loaded the benlysta in the traditional sodium alginate (SA) hydrogel to investigate the potential application of the drug-loaded hydrogel for skin dressing or hypodermic drug. Live/dead staining images and the CCK-8 results showed that the benlysta-loaded hydrogel could promote the growth of human epidermal cells (HaCat), fibroblasts (L929), and endothelial cells while inhibiting the aggregation of inflammatory cells (macrophages). In addition, the hydrogel degradation and drug release are slow and controllable, and the gel time of drug-loaded hydrogel can be adjusted by adding sodium alginate ratios according to the requirement. In summary, we prepared a time-dependent drug-loaded hydrogel for potential application in the treatment of skin injury that may be caused by other diseases.

Recent Advances in Extracellular Matrix for Engineering Stem Cell Responses.

Stem cell transplantation is an advanced medical technology, which brings hope for the treatment of some difficult diseases in the clinic. Attributed to its self-renewal and differential ability, stem cell research has been pushed to the forefront of regenerative medicine and has become a hot topic in tissue engineering. The surrounding extracellular matrix has physical functions and important biological significance in regulating the life activities of cells, which may play crucial roles for in situ inducing specific differentiation of stem cells. In this review, we discuss the stem cells and their engineering application, and highlight the control of the fate of stem cells, we offer our perspectives on the various challenges and opportunities facing the use of the components of extracellular matrix for stem cell attachment, growth, proliferation, migration and differentiation.