Temperature-Gating Titania Nanotubes Regulate Migration of Endothelial Cells

Glucose oxidase and ruthenium nanorods-embedded self-healing polyvinyl alcohol/polyethylene imine hydrogel for simultaneous photothermal/photodynamic/starvation therapy and skin reconstruction

Tumor recurrence and wound healing represent significant burdens for tumor patients after the surgical removal of melanomas. Wound dressings with wound healing and anticancer therapeutic abilities could help to solve these issues. Thus, a hybrid hydrogel made of polyvinyl alcohol (PVA) and polyethylene imine (PEI) was prepared by cross-linking imine bond and boronic acid bond. This hydrogel was loaded with ruthenium nanorods (Ru NRs) and glucose oxidase (GOx) and named as nanocomposite hydrogel (Ru/GOx@Hydrogel), exhibiting remarkable photothermal/photodynamic/starvation antitumor therapy and wound repair abilities. Ru NRs are bifunctional phototherapeutic agents that simultaneously exhibit intrinsic photothermal and photodynamic functions. Three-dimensional composite hydrogel loaded with GOx can also consume glucose in the presence of O2 during tumor starvation therapy. Near-infrared (NIR) light-triggered hyperthermia can not only promote the consumption of glucose, but also facilitate the ablation of residual cancer cells. The antitumor effect of the Ru/GOx@Hydrogel resulted in significant improvements, compared to those observed with either phototherapy or starvation therapy alone. Additionally, the postoperative wound was substantially healed after treatment with Ru/GOx@Hydrogel and NIR irradiation. Therefore, the Ru/GOx@Hydrogel can be used as a multi-stimulus-responsive nanoplatform that could facilitate on-demand controlled drug release, and be used as a promising postoperative adjuvant in combination therapy.

Integrated photo-inspired antibacterial polyvinyl alcohol/carboxymethyl cellulose hydrogel dressings for pH real-time monitoring and accelerated wound healing

Recurrent infection of chronic wounds remains a major clinical challenge. Recently, the hydrogel antibacterial materials have attracted extensive attention for preventing infection in wound healing. In this study, a hybrid hydrogel made of polyvinyl alcohol - iodine (PAI), sodium carboxymethyl cellulose (CMC), and carbamino quantum dot (CQDs) was prepared by the cross-linking of hydrogen bonds, named as polyvinyl alcohol‑iodine/sodium carboxymethyl cellulose/carbon quantum dots (PAI/CMC/CQDs). The composite hydrogels exhibited the outstanding photothermal conversion efficiency with near infrared (NIR) light irradiation, and the high antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Meanwhile, the elevated temperature of the composite hydrogels up to ~45 °C was able to stimulate the migration of epidermal cell to accelerate skin repair. Given that PAI and CQDs could respond to different pH values (5-8), the real-time would pH information was provided by the visible light and fluorescent light dual monitoring system by naked eye. Moreover, the visible-fluorescent images could be collected and transformed into RGB signals to quantify the would pH levels, avoiding secondary injuries caused by frequent dressing changes. PAI/CMC/CQDs was demonstrated the significant therapeutic effect on chronic wounds by eliminating bacterial infections and promoting skin repair under the smart RGB monitoring system.

Metal-Phenolic Networks Assembled on TiO2 Nanospikes for Antimicrobial Peptide Deposition and Osteoconductivity Enhancement in Orthopedic Applications

The lack of antimicrobial and osteoconductive activities of titanium (Ti) for orthopedic implants has led to problems such as infection and structural looseness, which bring physical and psychological sufferings to patients as well as economic burden on the healthcare system. To endow Ti implants with anti-infective function and bioactivity, in this study, we successfully constructed TiO2 nanospike (TNS) structure on the surface of Ti followed by assembling metal-polyphenol networks (MPNs) and depositing antimicrobial peptides (AMPs). The TNSs' structure can disrupt the bacteria by physical puncture, and it was also proved to have excellent photothermal conversion performance upon near-infrared light irradiation. Furthermore, with the assistance of contact-active chemo bactericidal efficacy of AMPs, TNS-MPN-AMP nanocoating achieved physical/photothermal/chemo triple-synergistic therapy against pathogenic bacteria. The anti-infective efficiency of this multimodal treatment was obviously improved, with an antibacterial ratio of >99.99% in vitro and 95.03% in vivo. Moreover, the spike-like nanostructure of TNSs and the bioactive groups from MPNs and AMPs not only demonstrated desirable biocompatibility but also promoted the surface hydroxyapatite formation in simulated body fluid for further osseointegration enhancement. Altogether, this multifaceted TNS-MPN-AMP nanocoating endowed Ti implants with enhanced antibacterial activity, excellent cytocompatibility, and desirable osteoconductive ability.