A hyaluronic acid / chitosan composite functionalized hydrogel based on enzyme-catalyzed and Schiff base reaction for promoting wound healing.

The healing of full-thickness skin defect has been a clinical challenge. Hydrogels with multiple functions inspired by extracellular matrix are expected to be used as wound dressing. In this paper, dopamine-grafted oxidized hyaluronic acid was blended with quaternary ammonium chitosan to form a composite functionalized hydrogel by enzyme-catalyzed cross-linking and Schiff base reaction. The hydrogel has convenient preparation, good biocompatibility, antibacterial and antioxidant, high adhesion and self-healing properties. The results in vivo show that the hydrogel can effectively close the wound and accelerate the speed of wound healing by up-regulating the expression of angiogenic protein and promoting the distribution of collagen deposition more uniform and regular. It is expected that this composite functionalized hydrogel dressing has great potential in wound regeneration.

Hydrogels for the Treatment of Myocardial Infarction: Design and Therapeutic Strategies.

Cardiovascular diseases (CVDs) have become the leading global burden of diseases in recent years and are the primary cause of human mortality and loss of healthy life expectancy. Myocardial infarction (MI) is the top cause of CVDs-related deaths, and its incidence is increasing worldwide every year. Recently, hydrogels have garnered great interest from researchers as a promising therapeutic option for cardiac tissue repair after MI. This is due to their excellent properties, including biocompatibility, mechanical properties, injectable properties, anti-inflammatory properties, antioxidant properties, angiogenic properties, and conductive properties. This review discusses the advantages of hydrogels as a novel treatment for cardiac tissue repair after MI. The design strategies of various hydrogels in MI treatment are then summarized, and the latest research progress in the field is classified. Finally, the future perspectives of this booming field are also discussed at the end of this review.

Application of cell membrane-functionalized biomimetic nanoparticles in the treatment of glioma.

Glioma is one of the most common malignant tumors with characteristics of strong invasion and high postoperative recurrence rate, which seriously threatens human health. Nanoparticles as an emerging drug delivery system have promoted the development of glioma therapy. However, blocking of nanoparticles by the blood-brain barrier is still serious problem for the use of nanoparticles in glioma therapy. In this context, traditional nanoparticles are dressed with natural cell membranes to prepare biomimetic nanoparticles. Biomimetic nanoparticles show longer blood circulation time, excellent homologous targeting and outstanding immune escape capacity, which significantly improve the accumulation of nanoparticles at the tumor site. The therapeutic effect for glioma has been raised to an advanced level. This review focuses on the preparations and applications of cell membrane-functionalized biomimetic nanoparticles, as while as the advantages and problems of biomimetic nanoparticles in the treatment of glioma. In particular, the approach of using biomimetic nanoparticles to cross the blood-brain barrier is analyzed, in the hope of providing new ideas for further developments in crossing the blood-brain barrier and in glioma therapy.

Tough, Recyclable, and Degradable Elastomers for Potential Biomedical Applications.

Elastomers have many industrial, medical and commercial applications, however, their huge demand raises an important question of how to dispose of the out-of-service elastomers. Ideal elastomers that are concurrently tough, recyclable, and degradable are in urgent need, but their preparation remains a rigorous challenge. Herein, a polycaprolactone (PCL) based polyurethane elastomer is designed and prepared to meet this demand. Owing to the presence of dynamic coordination bond and the occurrence of strain-induced crystallization, the obtained elastomer exhibits a high toughness of ≈372 MJ m-3 and an unprecedented fracture energy of ≈646 kJ m-2 , which is much higher than natural rubber (≈50 MJ m-3 for toughness and ≈10 kJ m-2 for fracture energy). In addition, the elastomer can be recycled at least three times using solvent without losing its mechanical properties and can be degraded by lipase in ≈2 months. Finally, biological experiments demonstrate that the elastomer possesses good biocompatibility and can facilitate wound healing in mice when used as sutures. It is believed that the obtained elastomer meets the requirements for next-generation elastomers and is expected to be used in emerging fields such as biomedicine, flexible electronics, robotics and beyond.

Durable and Nontoxic Natural Rubber-Based Composites with Antibacterial Properties.

Natural rubber latex (NRL) has prophylactic properties and is used to make pathogen-isolating products like condoms and surgical gloves. However, obtaining NRL and casting it into durable products are challenging. Consequently, progress in the research and development of medical NRL products has been slow. This study aims to strengthen NR and induce it with bactericidal properties. In this regard, we introduce inorganic whiskers into the NRL and synthesize whiskers/NR composites with strong mechanical and antibacterial properties. The method proposed herein is a template method, which can rapidly and efficiently reveal the antibacterial effect of the composite latex, providing convenience for research institutions and factories studying antibacterial latex. A complete system is established for studying the antibacterial medical NRL, and a precedent is set for the relevant products.

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.

Hydrogel Preparation Methods and Biomaterials for Wound Dressing.

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.

Hyaluronic acid/polyethyleneimine nanoparticles loaded with copper ion and disulfiram for esophageal cancer.

In the clinical treatment of cancer, improving the effectiveness and targeting of drugs has always been a bottleneck problem that needs to be solved. In this contribution, inspired by the targeted inhibition on cancer from combination application of disulfiram and divalent copper ion (Cu2+), we optimized the concentration of disulfiram and Cu2+ ion for inhibiting esophageal cancer cells, and loaded them in hyaluronic acid (HA)/polyethyleneimine (PEI) nanoparticles with specific scales, in order to improve the effectiveness and targeting of drugs. The in vitro cell experiments demonstrated that more drug loaded HA/PEI nanoparticles accumulated to the esophageal squamous cell carcinoma (Eca109) and promoted higher apoptosis ratio of Eca109. Both in vitro and in vivo biological assessment verified that the disulfiram/Cu2+ loaded HA/PEI nanoparticles promoted the apoptosis of cancer cells and inhibited the tumor proliferation, but had no toxicity on other normal organs.

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.

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.

Nanomaterials for Angiogenesis in Skin Tissue Engineering.

Damage to skin tissue, which causes the disorder of the patient's body homeostasis, threatens the patient's life and increases the personal and social treatment burden. Angiogenesis, a key step in the wound healing process, provides sufficient oxygen and nutrients to the wound area. However, traditional clinical interventions are not enough to stabilize the formation of the vascular system to support wound healing. Due to the unique properties and multiple functions of nanomaterials, it has made a major breakthrough in the application of medicine. Nanomaterials provide a more effective treatment to hasten the angiogenesis and wound healing, by stimulating fundamental factors in the vascular regeneration phase. In the present review article, the basic stages and molecular mechanisms of angiogenesis are analyzed, and the types, applications, and prospects of nanomaterials used in angiogenesis are detailed. Impact statement Wound healing (especially chronic wounds) is currently a clinically important issue. The long-term nonhealing of chronic wounds often plagues patients, medical systems, and causes huge losses to the social economy. There is currently no effective method of treating chronic wounds in the clinic. Angiogenesis is an important step in wound healing. Nanomaterials had properties that are not found in conventional materials, and they have been extensively studied in angiogenesis. This review article provides readers with the molecular mechanisms of angiogenesis and the types and applications of angiogenic nanomaterials, hoping to bring inspiration to overcome chronic wounds.