Multivalent Phthalocyanine-Based Cationic Polymers with Enhanced Photodynamic Activity for the Bacterial Capture and Bacteria-Infected Wound Healing

Antibacterial, Fatigue-Resistant, and Self-Healing Dressing from Natural-Based Composite Hydrogels for Infected Wound Healing

The treatment of infected wounds faces substantial challenges due to the high incidence and serious infection-related complications. Natural-based hydrogel dressings with favorable antibacterial properties and strong applicability are urgently needed. Herein, we developed a composite hydrogel by constructing multiple networks and loading ciprofloxacin for infected wound healing. The hydrogel was synthesized via a Schiff base reaction between carboxymethyl chitosan and oxidized sodium alginate, followed by the polymerization of the acrylamide monomer. The resultant hydrogel dressing possessed a good self-healing ability, considerable compression strength, and reliable compression fatigue resistance. In vitro assessment showed that the composite hydrogel effectively eliminated bacteria and exhibited an excellent biocompatibility. In a model of Staphylococcus aureus-infected full-thickness wounds, wound healing was significantly accelerated without scars through the composite hydrogel by reducing wound inflammation. Overall, this study opens up a new way for developing multifunctional hydrogel wound dressings to treat wound infections.

Unleashing the Power of PET-RAFT Polymerization: Journey from Porphyrin-Based Photocatalysts to Combinatorial Technologies and Advanced Bioapplications

The emergence of photoinduced energy/electron transfer-reversible addition-fragmentation chain transfer polymerization (PET-RAFT) not only revolutionized the field of photopolymerization but also accelerated the development of porphyrin-based photocatalysts and their analogues. The continual expansion of the monomer family compatible with PET-RAFT polymerization enhances the range of light radiation that can be harnessed, providing increased flexibility in polymerization processes. Furthermore, the versatility of PET-RAFT polymerization extends beyond its inherent capabilities, enabling its integration with various technologies in diverse fields. This integration holds considerable promise for the advancement of biomaterials with satisfactory bioapplications. As researchers delve deeper into the possibilities afforded by PET-RAFT polymerization, the collaborative efforts of individuals from diverse disciplines will prove invaluable in unleashing its full potential. This Review presents a concise introduction to the fundamental principles of PET-RAFT, outlines the progress in photocatalyst development, highlights its primary applications, and offers insights for future advancements in this technique, paving the way for exciting innovations and applications.

POSS engineering of squaraine nanoparticle with high photothermal conversion efficiency for photothermal therapy

Photothermal therapy (PTT) has been extensively studied due to its promising therapeutic effects and potential for development in cancer treatments. Central to PTT is the development of photothermal agents (PTAs). This study presents a novel nanoparticle called POSS-SQ, which satisfies the necessary conditions to function as a PTA. Comprised of squaraine (SQ) and polyhedral oligomeric sesquisiloxane (POSS), POSS-SQ NPs exhibit strong near-infrared (NIR) absorption and high photothermal conversion efficiency (PCE) attributable to the intermolecular electron transfer in SQ. Furthermore, POSS when modified with polyethylene glycol (PEG) through "click" chemistry, effectively enhances cell permeability and biocompatibility of the nanoparticles. Photothermal experiments reveal that POSS-SQ NPs demonstrate concentration and laser power dependence, with a PCE of 67.2%. In vitro and in vivo experiments confirm the excellent biosafety and tumor growth inhibition potential of POSS-SQ NPs under laser irradiation, attributed to the synergistic effects of enhanced cell permeability and exceptional photothermal properties. This research highlights the possibility of obtaining PTAs with high PCE and excellent biocompatibility by combining SQ-N and POSS, offering a new approach for designing and developing more efficient PTAs to enhance better PTT outcomes.

Photothermal antibacterial materials to promote wound healing

Wound healing is a crucial process that restores the integrity and function of the skin and other tissues after injury. However, external factors, such as infection and inflammation, can impair wound healing and cause severe tissue damage. Therefore, developing new drugs or methods to promote wound healing is of great significance. Photothermal therapy (PTT) is a promising technique that uses photothermal agents (PTAs) to convert near-infrared radiation into heat, which can eliminate bacteria and stimulate tissue regeneration. PTT has the advantages of high efficiency, controllability, and low drug resistance. Hence, nanomaterial-based PTT and its related strategies have been widely explored for wound healing applications. However, a comprehensive review of PTT-related strategies for wound healing is still lacking. In this review, we introduce the physiological mechanisms and influencing factors of wound healing, and summarize the types of PTAs commonly used for wound healing. Then, we discuss the strategies for designing nanocomposites for multimodal combination treatment of wounds. Moreover, we review methods to improve the therapeutic efficacy of PTT for wound healing, such as selecting the appropriate wound dressing form, controlling drug release, and changing the infrared irradiation window. Finally, we address the challenges of PTT in wound healing and suggest future directions.

Photo-Stimuli-Responsive CuS Nanomaterials as Cutting-Edge Platform Materials for Antibacterial Applications

Photo-stimuli-responsive therapeutic nanomaterials have gained widespread attention as frontline materials for biomedical applications. The photoactivation strategies are classified as single-modality (based on either reactive oxygen species (ROS)-based photodynamic therapy (PDT), hyperthermia-based photothermal therapy (PTT)), or dual-modality (which combines PDT and PTT). Due to its minimal invasiveness, phototherapy has been extensively applied as an efficient therapeutic platform for many diseases, including skin cancers. However, extensive implementation of phototherapy to address the emergence of multidrug-resistant (MDR) bacterial infections remains challenging. This review focuses on copper sulfide (CuS) nanomaterials as efficient and cost-effective PDT and PTT therapeutic nanomaterials with antibacterial activity. The features and merits of CuS nanomaterials as therapeutics are compared to those of other nanomaterials. Control of the dimensions and morphological complexity of CuS nanomaterials through judicious synthesis is then introduced. Both the in vitro antibacterial activity and the in vivo therapeutic effect of CuS nanomaterials and derivative nanocomposites composed of 2D nanomaterials, polymers, metals, metal oxides, and proteins are described in detail. Finally, the perspective of photo-stimuli-responsive CuS nanomaterials for future clinical antibacterial applications is highlighted. This review illustrates that CuS nanomaterials are highly effective, low-toxic, and environmentally friendly antibacterial agents or platform nanomaterials for combatting MDR bacterial infections.