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The management of diabetic wounds remains a critical therapeutic challenge. Platelet-rich plasma (PRP) gel, PRP-derived exosomes (PRP-Exos), and mesenchymal stem cell-derived exosomes (MSC-Exos) have demonstrated therapeutic potential in wound treatment. Unfortunately, their poor mechanical properties, the short half-lives of growth factors (GFs), and the burst release of GFs and exosomes have limited their clinical applications. Furthermore, proteases in diabetic wounds degrade GFs, which hampers wound repair. Silk fibroin is an enzyme-immobilization biomaterial that could protect GFs from proteases. Herein, we developed novel dual-crosslinked hydrogels based on silk protein (SP) (sericin and fibroin), including SP@PRP, SP@MSC-Exos, and SP@PRP-Exos, to promote diabetic wound healing synergistically. SP@PRP was prepared from PRP and SP using calcium gluconate/thrombin as agonist, while SP@PRP-Exos and SP@MSC-Exos were derived from exosomes and SP with genipin as crosslinker. SP provided improved mechanical properties and enabled the sustained release of GFs and exosomes, thereby overcoming the limitations of PRP and exosomes in wound healing. The dual-crosslinked hydrogels displayed shear-induced thinning, self-healing, and eradication of microbial biofilms in a bone-mimicking environment. In vivo, the dual-crosslinked hydrogels contributed to faster diabetic wound healing than PRP and SP by upregulating GFs expression, down-regulating matrix metalloproteinase-9 expression, and by promoting an anti-NETotic effect, angiogenesis, and re-epithelialization. Hence, these dual-crosslinked hydrogels have the potential to be translated into a new generation of diabetic wound dressings.

Hydrogel-based burn wound dressings with excellent antibacterial, antifungal, and mechanical properties are ideal biomaterials to promote infected large burn wound healing. In this study, the hydrogel synthesized by repetitive freezing-thawing consists of poly (vinyl alcohol) (PVA), silk sericin (SS), and azithromycin (AZM), with genipin (GNP) as crosslinker. The FTIR showed that all hydrogel components were successfully blended. The swelling ratio, porosity, cell attachment, and proliferation improved with SS incorporation, while increased PVA content enhanced the mechanical performance of the hydrogel. The inclusion of AZM improved the antimicrobial property of the hydrogel towards Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The hydrogel showed sustained SS and AZM releases as well as cytocompatibility on keratinocytes and fibroblasts. Furthermore, the hydrogel displays skin adhesion ability when freeze-dried. In the in vivo study using an infected mouse full-thickness burn model with a 10% total body surface area, it was shown that burn injury led to increased inflammatory cytokine responses and macroscopic and microscopic alterations in the spleen and liver. The kidneys, on the other hand, revealed neither change. Interestingly, the prepared hydrogel had a better burn wound healing effect than the commercial Tegaderm™ film dressing, minimizing systemic burn effects. Hence, this novel hydrogel is projected to be a promising candidate for accelerated healing of infected burn wounds.

Abstract Electronic fibers used to fabricate wearable triboelectric nanogenerator (TENG) for harvesting human mechanical energy have been extensively explored. However, little attention is paid to their mutual advantages of environmental friendliness, mechanical properties, and stability. Here, we report a super-strong, biodegradable, and washable cellulose-based conductive macrofibers, which is prepared by wet-stretching and wet-twisting bacterial cellulose hydrogel incorporated with carbon nanotubes and polypyrrole. The cellulose-based conductive macrofibers possess high tensile strength of 449 MPa (able to lift 2 kg weights), good electrical conductivity (~ 5.32 S cm−1), and excellent stability (Tensile strength and conductivity only decrease by 6.7% and 8.1% after immersing in water for 1 day). The degradation experiment demonstrates macrofibers can be degraded within 108 h in the cellulase solution. The designed fabric-based TENG from the cellulose-base conductive macrofibers shows a maximum open-circuit voltage of 170 V, short-circuit current of 0.8 µA, and output power at 352 μW, which is capable of powering the commercial electronics by charging the capacitors. More importantly, the fabric-based TENGs can be attached to the human body and work as self-powered sensors to effectively monitor human motions. This study suggests the potential of biodegradable, super-strong, and washable conductive cellulose-based fiber for designing eco-friendly fabric-based TENG for energy harvesting and biomechanical monitoring.

Hydrogel-based burn wound dressings with excellent antibacterial, antifungal, and mechanical properties are ideal biomaterials to promote infected large burn wound healing. In this study, the hydrogel synthesized by repetitive freezing-thawing consists of poly (vinyl alcohol) (PVA), silk sericin (SS), and azithromycin (AZM), with genipin (GNP) as crosslinker. The FTIR showed that all hydrogel components were successfully blended. The swelling ratio, porosity, cell attachment, and proliferation improved with SS incorporation, while increased PVA content enhanced the mechanical performance of the hydrogel. The inclusion of AZM improved the antimicrobial property of the hydrogel towards Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The hydrogel showed sustained SS and AZM releases as well as cytocompatibility on keratinocytes and fibroblasts. Furthermore, the hydrogel displays skin adhesion ability when freeze-dried. In the in vivo study using an infected mouse full-thickness burn model with a 10% total body surface area, it was shown that burn injury led to increased inflammatory cytokine responses and macroscopic and microscopic alterations in the spleen and liver. The kidneys, on the other hand, revealed neither change. Interestingly, the prepared hydrogel had a better burn wound healing effect than the commercial Tegaderm™ film dressing, minimizing systemic burn effects. Hence, this novel hydrogel is projected to be a promising candidate for accelerated healing of infected burn wounds. [ABSTRACT FROM AUTHOR]