Human Keratinocytes and Fibroblasts Co-Cultured on Silk Fibroin Scaffolds Exosomally Overrelease Angiogenic and Growth Factors

Biological Coatings: Advanced Strategies Driving Multifunctionality and Clinical Potential in Dermal Substitutes

Skin tissue defects caused by various acute and chronic etiologies frequently occur in clinical medicine. Traditional surgical repair methods have certain limitations, while dermal substitutes combined with skin grafting have become an alternative to conventional surgery. Biological coatings, by loading bioactive substances such as polysaccharides and proteins, or by using bioactive substances as carriers, can promote cell adhesion, proliferation, and differentiation. This optimizes the mechanical properties and biocompatibility of the substitutes, enhances their antibacterial properties, and improves their feasibility for clinical application. This paper explores various common biological coating materials and the construction methods used in the field of dermal substitutes. It highlights the importance and necessity of biological coatings in the development of multifunctional designs for dermal substitutes. By summarizing the current research, this paper aims to offer new insights and references for the multifunctional design and clinical application of dermal substitutes.

Current application of tissue-engineered dermal scaffolds mimicking the extracellular matrix microenvironment in wound healing

With the continuous advancement of materials science, cell biology, and biotechnology, tissue engineering has introduced novel solutions to traditional wound healing approaches, particularly demonstrating significant potential in addressing complex or non-healing wounds. One of the key technologies in this field, dermal scaffolds, serve as wound coverage materials that mimic the structural framework of the dermis. They primarily assume the function of extracellular matrix, providing space for cell attachment, migration, and proliferation, thus supporting cellular growth and regulating multiple biological processes in healing. Tissue engineering utilizes combinations of natural or synthetic scaffolds, seeded cells, or growth factors to induce distinct effects in angiogenesis, extracellular matrix deposition, and functional recovery. Therefore, various bioengineered dermal scaffolds hold significant potential for clinical translation in wound healing. This review outlines various extracellular matrix molecules utilized in the development of dermal scaffolds, emphasizes recent progress in cell- and growth factor-modified scaffolds, and discusses the challenges and future perspectives in this evolving field.

Engineered exosomes as a prospective therapy for diabetic foot ulcers

Diabetic foot ulcer (DFU), characterized by high recurrence rate, amputations and mortality, poses a significant challenge in diabetes management. The complex pathology involves dysregulated glucose homeostasis leading to systemic and local microenvironmental complications, including peripheral neuropathy, micro- and macro-angiopathy, recurrent infection, persistent inflammation and dysregulated re-epithelialization. Novel approaches to accelerate DFU healing are actively pursued, with a focus on utilizing exosomes. Exosomes are natural nanovesicles mediating cellular communication and containing diverse functional molecular cargos, including DNA, mRNA, microRNA (miRNA), lncRNA, proteins, lipids and metabolites. While some exosomes show promise in modulating cellular function and promoting ulcer healing, their efficacy is limited by low yield, impurities, low loading content and inadequate targeting. Engineering exosomes to enhance their curative activity represents a potentially more efficient approach for DFUs. This could facilitate focused repair and regeneration of nerves, blood vessels and soft tissue after ulcer development. This review provides an overview of DFU pathogenesis, strategies for exosome engineering and the targeted therapeutic application of engineered exosomes in addressing critical pathological changes associated with DFUs.

Silk Fibroin Materials: Biomedical Applications and Perspectives

The golden rule in tissue engineering is the creation of a synthetic device that simulates the native tissue, thus leading to the proper restoration of its anatomical and functional integrity, avoiding the limitations related to approaches based on autografts and allografts. The emergence of synthetic biocompatible materials has led to the production of innovative scaffolds that, if combined with cells and/or bioactive molecules, can improve tissue regeneration. In the last decade, silk fibroin (SF) has gained attention as a promising biomaterial in regenerative medicine due to its enhanced bio/cytocompatibility, chemical stability, and mechanical properties. Moreover, the possibility to produce advanced medical tools such as films, fibers, hydrogels, 3D porous scaffolds, non-woven scaffolds, particles or composite materials from a raw aqueous solution emphasizes the versatility of SF. Such devices are capable of meeting the most diverse tissue needs; hence, they represent an innovative clinical solution for the treatment of bone/cartilage, the cardiovascular system, neural, skin, and pancreatic tissue regeneration, as well as for many other biomedical applications. The present narrative review encompasses topics such as (i) the most interesting features of SF-based biomaterials, bare SF's biological nature and structural features, and comprehending the related chemo-physical properties and techniques used to produce the desired formulations of SF; (ii) the different applications of SF-based biomaterials and their related composite structures, discussing their biocompatibility and effectiveness in the medical field. Particularly, applications in regenerative medicine are also analyzed herein to highlight the different therapeutic strategies applied to various body sectors.

A Simplified Method for the Preparation of Highly Conductive and Flexible Silk Nanofibrils/MXene Membrane

Silk nanofibers (SNF) have great applications in high-performance functional nanocomposites due to their excellent mechanical properties, biocompatibility, and degradability. However, the preparation of SNF by traditional methods often requires the use of some environmentally harmful or toxic reagents, limiting its application in green chemistry. In this paper, we successfully prepared SNF using natural silk as raw material and solvent stripping technology by adjusting the solvent concentration and solution ratio (the diameter of about 120 nm). Using the above SNFs as raw materials, SNF membranes were prepared by vacuum filtration technology. In addition, we prepared an SNF/MXene nanocomposite material with excellent humidity sensitivity by simply coating MXene nanosheets with silk fibers. The conductivity of the material can approach 1400.6 S m-1 with excellent mechanical strength (51.34 MPa). The SNF/MXene nanocomposite material with high mechanical properties, high conductivity, and green degradability can be potentially applied in the field of electromagnetic interference (EMI) shielding, providing a feasible approach for the development of functional nanocomposite materials.