Hyaluronic acid (HA) is a large non-sulfated glycosaminoglycan that is the main component of the extracellular matrix (ECM). Because of its strong and diversified functions applied in broad fields, HA has been widely studied and reported previously. The molecular properties of HA and its derivatives, including a wide range of molecular weights but distinct effects on cells, moisture retention and anti-aging, and CD44 targeting, promised its role as a popular participant in tissue engineering, wound healing, cancer treatment, ophthalmology, and cosmetics. In recent years, HA and its derivatives have played an increasingly important role in the aforementioned biomedical fields in the formulation of coatings, nanoparticles, and hydrogels. This article highlights recent efforts in converting HA to smart formulation, such as multifunctional coatings, targeted nanoparticles, or injectable hydrogels, which are used in advanced biomedical application.

Wounds have become one of the causes of death worldwide. The metabolic disorder of the wound microenvironment can lead to a series of serious symptoms, especially chronic wounds that bring great pain to patients, and there is currently no effective and widely used wound dressing. Therefore, it is important to develop new multifunctional wound dressings. Hydrogel is an ideal dressing candidate because of its 3D structure, good permeability, excellent biocompatibility, and ability to provide a moist environment for wound repair, which overcomes the shortcomings of traditional dressings. This article first briefly introduces the skin wound healing process, then the preparation methods of hydrogel dressings and the characteristics of hydrogel wound dressings made of natural biomaterials and synthetic materials are introduced. Finally, the development prospects and challenges of hydrogel wound dressings are discussed.

Scars caused by skin injuries after burns, wounds, abrasions and operations have serious physical and psychological effects on patients. In recent years, the research of scar free wound repair has been greatly expanded. However, understanding the complex mechanisms of wound healing, in which various cells, cytokines and mechanical force interact, is critical to developing a treatment that can achieve scarless wound healing. Therefore, this paper reviews the types of wounds, the mechanism of scar formation in the healing process, and the current research progress on the dual consideration of wound healing and scar prevention, and some strategies for the treatment of scar free wound repair.

Skin injury is a major problem threatening human physical and mental health, 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 Aloe vera plays an important role in promoting wound healing. Adding Aloe 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 Aloe vera in wound healing. In addition, the types of wound dressing and the applications of Aloe vera in wound dressing will be discussed.

Magnesium (Mg) and its alloys, as potential biodegradable materials, have drawn wide attention in the cardiovascular stent field because of their appropriate mechanical properties and biocompatibility. Nevertheless, the occurrence of thrombosis, inflammation, and restenosis of implanted Mg alloy stents caused by their poor corrosion resistance and insufficient endothelialization restrains their anticipated clinical applications. Numerous surface treatment tactics have mainly striven to modify the Mg alloy for inhibiting its degradation rate and enduing it with biological functionality. This review focuses on highlighting and summarizing the latest research progress in functionalized coatings on Mg alloys for cardiovascular stents over the last decade, regarding preparation strategies for metal oxide, metal hydroxide, inorganic nonmetallic, polymer, and their composite coatings; and the performance of these strategies in regulating degradation behavior and biofunction. Potential research direction is also concisely discussed to help guide biological functionalized strategies and inspire further innovations. It is hoped that this review can give assistance to the surface modification of cardiovascular Mg-based stents and promote future advancements in this emerging research field.

In the past few decades, there have been potential applications for stem cell replacement therapy in the treatment of nervous system damage resulting from diseases or traumatic brain injury (TBI). However, the insufficient number of transplanted stem cells and low survival rate caused by a series of negative conditions limit the therapeutic effect. In this contribution, we developed an injectable hydrogel composed of sodium alginate (SA) and hyaluronic acid (HA) as a tissue scaffold to create a more optimal microenvironment for stem cells after implantation. The gelation time of the HA/SA hydrogel exceeded 6 min, which satisfied the requirements for injection performance, and the high ratios of water content and slower degradation speed affirmed that the HA/SA hydrogel is a preferable stem cell scaffold. As a tissue engineering scaffold, the HA/SA hydrogel exhibited appropriately porous structures for stem cell loading and good rheological behavior, which contributed to stem cell differentiation. The in vitro culture experiment proved that the HA/SA scaffold performed well on hUC-MSCs with higher viability ratio and proliferation. Further in vivo tests indicated that the HA/SA scaffold not only protected the injected human umbilical cord mesenchymal stem cells (hUC-MSCs) so that they could maintain a higher survival ratio, but it also contributed to the regeneration of endogenous nerve cells. In summary, this injectable HA/SA hydrogel has the potential to be used for stem cell tissue engineering and support the physiological function recovery of TBI patients.