Editorial: Biomaterials for Skin Wound Repair: Tissue Engineering, Guided Regeneration, and Wound Scarring Prevention

Skin-on-a-chip technologies towards clinical translation and commercialization

Skin is the largest organ of the human body which plays a critical role in thermoregulation, metabolism (e.g. synthesis of vitamin D), and protection of other organs from environmental threats, such as infections, microorganisms, ultraviolet radiation, and physical damage. Even though skin diseases are considered to be less fatal, the ubiquity of skin diseases and irritation caused by them highlights the importance of skin studies. Furthermore, skin is a promising means for transdermal drug delivery, which requires a thorough understanding of human skin structure. Current animal andin vitrotwo/three-dimensional skin models provide a platform for disease studies and drug testing, whereas they face challenges in the complete recapitulation of the dynamic and complex structure of actual skin tissue. One of the most effective methods for testing pharmaceuticals and modeling skin diseases are skin-on-a-chip (SoC) platforms. SoC technologies provide a non-invasive approach for examining 3D skin layers and artificially creating disease models in order to develop diagnostic or therapeutic methods. In addition, SoC models enable dynamic perfusion of culture medium with nutrients and facilitate the continuous removal of cellular waste to further mimic thein vivocondition. Here, the article reviews the most recent advances in the design and applications of SoC platforms for disease modeling as well as the analysis of drugs and cosmetics. By examining the contributions of different patents to the physiological relevance of skin models, the review underscores the significant shift towards more ethical and efficient alternatives to animal testing. Furthermore, it explores the market dynamics ofin vitroskin models and organ-on-a-chip platforms, discussing the impact of legislative changes and market demand on the development and adoption of these advanced research tools. This article also identifies the existing obstacles that hinder the advancement of SoC platforms, proposing directions for future improvements, particularly focusing on the journey towards clinical adoption.

Porous Functionally Graded Scaffold prepared by a single-step freeze-drying process. A bioinspired approach for wound care

Nowadays, chronic wounds are the major cause of morbidity worldwide and the healthcare costs related to wound care are a billion-dollar issue; chronic wounds involve a non-healing process that makes necessary the application of advanced wound dressings to promote skin integrity recovery. Functionally Graded Scaffolds (FGSs) are currently driving interest as promising candidates in mimicking the skin tissue environment and, thus, in enhancing a faster and more effective wound healing process. Aim of the present work was to design and develop a porous FGS based on κ-carrageenan (κCG) for the management of chronic skin wounds; a freeze-drying process was optimized to obtain in a single-step a three-layered FGS characterized by a pore size gradient functional to mimic the structure of native skin tissue. In addition to κCG, arginine and whey protein isolate were used as multifunctional agents for FGS preparation; these substances can not only intervene in some stages of wound healing but are able to establish non-covalent interactions with κCG, which were responsible for the production of layers with different pore size, water content capability and mechanical properties. Cell migration, adhesion and proliferation within the FGS structure were evaluated in vitro on fibroblasts and FGS wound healing potential was also studied in vivo on a murine model.

The effect of silicon groups on the physicochemical property and bioactivity of L-phenylalanine derived poly(amide-imide)

Poly(amide-imide) (PAI), serving as a synthetic polymer, has been widely used in industry for excellent mechanical properties, chemical resistance and high thermal stability. However, lack of suitable cell niche and biological activity limited the further application of PAI in biomedical engineering. Herein, silicon modified L-phenylalanine derived poly(amide-imide) (PAIS) was synthesized by introducing silica to L-phenylalanine derived PAI to improve physicochemical and biological performances. The influence of silicon amount on physicochemical, immune, and angiogenic performances of PAIS were systemically studied. The results show that PAIS exerts excellent hydrophilic, mechanical, biological activity. PAIS shows no effects on the number of macrophages, but can regulate macrophage polarization and angiogenesis in a dose-dependent manner. This study advanced our understanding of silicon modification in PAI can modulate cell responses via initiating silicon concentration regulation. The acquired knowledge will provide a new strategy to design and optimize biomedical PAI in the future.

Construction of chitosan/Ag nanocomposite sponges and their properties

Chitosan/Ag nanocomposite sponges were prepared by soaking the chitosan hydrogels in AgNO₃ aqueous solution, which was heated at 80 °C to synthesize Ag nanoparticles (AgNPs) in the porous chitosan matrix and freeze-dried. The structure and properties of the nanocomposite sponges were characterized by FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), and compressive testing. In our findings, the pores of the chitosan hydrogel were used as a microreactor to synthesize AgNPs, which could distribute evenly on the chitosan matrix. The chitosan/Ag nanocomposite sponges exhibited good mechanical properties, suitable water vapor transmission and noncytotoxicity. Antibacterial test revealed their excellent antibacterial activity against Staphylococcus aureus and E. coli. The chitosan/Ag nanocomposite sponges would have great potential as wound dressings due to their good properties and facile industrialization.