Photothermal-Irradiated Polyethyleneimine-Polypyrrole Nanopigment Film-Coated Polyethylene Fabrics for Infrared-Inspired with Pathogenic Evaluation

Physicochemical properties of bacterial cellulose/phototherapeutic polypyrrole/antibacterial chitosan composite membranes and their evaluation as chronic wound dressings

Bacterial cellulose (BC) is a natural fiber membrane and has been applied in many biomedical applications. Herein, it was used as the main scaffold to prepare wound dressings for treating diabetic skin wounds. Polypyrrole (PPy) was first synthesized by in situ oxidative polymerization within BC membrane and applied as a photothermal agent, followed by coating with chitosan (CS) to improve the biocompatibility and antibacterial properties. SEM pictures revealed sub-micron PPy particles ranging from 100 to 200 nm were formed and attached to the BC fibrils, whereas CS formed a thin, porous layer on the surface. FTIR analysis showed that there was hydrogen bonding between BC, PPy and CS components. The crystalline structure of BC was maintained yet with decreased crystallinity by addition of PPy and CS. The water absorption capability and water vapor transmission rate decreased by PPy incorporation owing to its hydrophobic nature, but they were regained by addition of hydrophilic CS. The prepared BC/PPy/CS membrane was biocompatible toward L929 cells and maintained hemocompatibility. Additionally, both PPy and CS contributed to the antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, while they demonstrated a potential for synergistic antibacterial effects when combined. Finally, the near-infrared (NIR)-driven photothermal-hyperthermic effects by PPy on lesions upregulated heat-shock protein (HSP) expression and anti-inflammatory properties by CS boosted restoration of diabetic wounds in vivo without the addition of any antibiotics or anti-inflammatory drugs. The results thus support using the BC/PPy/CS membrane for diabetic wound regeneration.

Maximizing light-to-heat conversion of Ti3C2Tx MXene metamaterials with wrinkled surfaces for artificial actuators

MXene, a promising photothermal nanomaterial, faces challenges due to densely stacked nanosheets with high refractive index (RI). To maximize photothermal performance, MXene metamaterials (m-MXenes) are developed with a superlattice with alternating MXene and organic layers, reducing RI and inducing multiple light reflections. This approach increases light absorption, inducing 90% photothermal conversion efficiency. The m-MXene is coated onto liquid crystal elastomer (LCE) fibers, as actuating platforms via a dip-coating (m-MXene/aLCE fiber), exhibiting excellent light-driven actuating owing to the synergetic effect of the patterned m-MXene laysers by structural deformation. The m-MXene/aLCE fibers lift ~6,900 times their weight and exhibit a work density 6 times higher than that of human skeletal muscle. It is applied to artificial muscles, grippers, and a bistable structure (a shooting device, and switchable gripper). Our study offers an effective strategy to enhance light absorption in 2D nanomaterials and contributes to advancements in photothermal technologies in various fields.

Biopolymer hydrogels and synergistic blends for tailored wound healing

Biopolymers have a transformative role in wound repair due to their biocompatibility, ability to stimulate collagen production, and controlled drug and growth factor delivery. This article delves into the biological parameters critical to wound healing emphasizing how combinations of hydrogels with reparative properties can be strategically designed to create matrices that stimulate targeted cellular responses at the wound site to facilitate tissue repair and recovery. Beyond a detailed examination of various biopolymer types and their functionalities in wound dressings acknowledging that the optimal choice depends on the specific wound type and application, this evaluation provides concepts for developing synergistic biopolymer blends to create next-generation dressings with enhanced efficiencies. Furthermore, the incorporation of therapeutic agents such as medications and wound healing accelerators into dressings to enhance their efficacy is examined. These agents often possess desirable properties such as antibacterial activity, antioxidant effects, and the ability to promote collagen synthesis and tissue regeneration. Finally, recent advancements in conductive hydrogels are explored, highlighting their capabilities in treatment and real-time wound monitoring. This comprehensive resource emphasizes the importance of optimizing ingredient efficiency besides assisting researchers in selecting suitable materials for personalized wound dressings, ultimately leading to more sophisticated and effective wound management strategies.

Alleviating rheumatoid arthritis with a photo-pharmacotherapeutic glycan-integrated nanogel complex for advanced percutaneous delivery

The prospective of percutaneous drug delivery (PDD) mechanisms to address the limitations of oral and injectable treatment for rheumatoid arthritis (RA) is increasing. These limitations encompass inadequate compliance among patients and acute gastrointestinal side effects. However, the skin's intrinsic layer can frequently hinder the percutaneous dispersion of RA medications, thus mitigating the efficiency of drug delivery. To circumvent this constraint, we developed a strontium ranelate (SrR)-loaded alginate (ALG) phototherapeutic hydrogel to assess its effectiveness in combating RA. Our studies revealed that this SrR-loaded ALG hydrogel incorporating photoelectrically responsive molybdenum disulfide nanoflowers (MoS2 NFs) and photothermally responsive polypyrrole nanoparticles (Ppy NPs) to form ALG@SrR-MoS2 NFs-Ppy NPs demonstrated substantial mechanical strength, potentially enabling delivery of hydrophilic therapeutic agents into the skin and significantly impeding the progression of RA. Comprehensive biochemical, histological, behavioral, and radiographic analyses in an animal model of zymosan-induced RA demonstrated that the application of these phototherapeutic ALG@SrR-MoS2 NFs-Ppy NPs effectively reduced inflammation, increased the presence of heat shock proteins, regulatory cluster of differentiation M2 macrophages, and alleviated joint degeneration associated with RA. As demonstrated by our findings, treating RA and possibly other autoimmune disorders with this phototherapeutic hydrogel system offers a distinctive, highly compliant, and therapeutically efficient method.

A Multifunctional Nanocatalytic Metal-Organic Framework as a Ferroptosis Amplifier for Mild Hyperthermia Photothermal Therapy

Hyperthermia therapy is considered an effective anticancer strategy. However, high temperature can trigger an excessive inflammatory response, leading to tumor self-protection, immunosuppression, metastasis, and recurrence. To address this issue, we reported a multifunctional photothermal nanoplatform to achieve mild hyperthermia photothermal therapy (mild PTT) based on cisplatin (DDP) and a ferrocene metal-organic framework (MOF-Fc) nanocomposite, which can specifically enhance ferroptosis-triggered oxidative stress levels and synchronously amplify mild hyperthermia PTT-mediated anticancer responses. Both in vitro and in vivo antineoplastic results verify the superiority of mild PTT with DDP/MOF-Fc@HA. The combination of DDP and MOF-Fc exhibits Fenton catalytic activity and glutathione depletion capacity, magnifying mild hyperthermia effects via the radical oxygen species (ROS)-adenosine triphosphate (ATP)-HSP silencing pathway, with important implications for clinical hyperthermia therapy.

Supercritical CO2-assisted fabrication of CM-PDA/SF/nHA nanofibrous scaffolds for bone regeneration and chemo-photothermal therapy against osteosarcoma

Concurrent treatment of tumor recurrence and bone defects after surgical resection of osteosarcoma remains a clinical challenge. Combination therapy based on local drug delivery systems shows great promise in the treatment of osteosarcoma. In this study, curcumin modified polydopamine nanoparticle loaded silk fibroin doped with nano-hydroxyapatite (CM-PDA/SF/nHA) nanofibrous scaffolds were developed to induce bone defect regeneration and chemo-photothermal synergistic effects against osteosarcoma. These scaffolds exhibited good photothermal conversion efficiency and photostability. Moreover, the results of ALP staining and alizarin red S (ARS) staining indicated that the CM-PDA/SF/1%nHA scaffolds had the most obvious promotion effect on early osteogenic differentiation. The results of in vitro and in vivo anti-osteosarcoma activity showed that the CM-PDA/SF/1%nHA scaffolds exhibited higher anti-osteosarcoma activity compared to the control and SF scaffolds. In addition, the CM-PDA/SF/1%nHA scaffolds could promote the proliferation and differentiation of bone marrow mesenchymal stem cells in vitro and new bone production in vivo. Thus, these results suggested that the CM-PDA/SF/1%nHA scaffolds could improve bone defect regeneration and achieve chemo-photothermal synergistic effects against osteosarcoma.

Ablation of Gap Junction Protein Improves the Efficiency of Nanozyme-Mediated Catalytic/Starvation/Mild-Temperature Photothermal Therapy

Reactive oxygen species (ROS)-mediated tumor catalytic therapy is typically hindered by gap junction proteins that form cell-to-cell channels to remove cytotoxic ROS, thereby protecting tumor cells from oxidative damage. In this work, a multifunctional nanozyme, FePGOGA, is designed and prepared by Fe(III)-mediated oxidative polymerization (FeP), followed by glucose oxidase (GOx) and GAP19 peptides co-loading through electrostatic and π-π interactions. The FePGOGA nanozyme exhibits excellent cascade peroxidase- and glutathione-oxidase-like activities that efficiently catalyze hydrogen peroxide conversion to hydroxyl radicals and convert reduced glutathione to oxidized glutathione disulfide. The loaded GOx starves the tumors and aggravates tumor oxidative stress through glucose decomposition, while GAP19 peptides block the hemichannels by inducing degradation of Cx43, thus increasing the accumulation of intracellular ROS, and decreasing the transport of intracellular glucose. Furthermore, the ROS reacts with primary amines of heat shock proteins to destroy their structure and function, enabling tumor photothermal therapy at the widely sought-after mild temperature (mildPTT, ≤45 °C). In vivo experiments demonstrate the significant antitumor effectof FePGOGA on cal27 xenograft tumors under near-infrared light irradiation. This study demonstrates the successful ablation of gap junction proteins to overcome resistance to ROS-mediated therapy, providing a regulator to suppress tumor self-preservation during tumor starvation, catalytic therapy, and mildPTT.

Targeted Wolfram-Doped Polypyrrole for Photonic Hyperthermia-Synergized Radiotherapy

Single ionizing radiation at a tolerable dose is ineffectual in eliminating malignancies but readily generates harmful effects on surrounding normal tissues. Herein, we intelligently fabricated novel wolfram-doped polypyrrole (WPPy) through a simple oxidative polymerization method with WCl₆ as an oxidizing catalyst, which possessed good biocompatibility, high photothermal conversion, and intensive radiosensitivity capacities to concurrently serve as a photothermal reagent and a radiosensitizer for hyperthermia-synergized radiotherapy (RT) against a malignant tumor. In comparison with traditional polypyrrole without noble metal doping, the innovative introduction of WCl₆ not only successfully launched the polymerization of a pyrrole monomer but also endowed WPPy with additional radiosensitization. More importantly, after further decoration with an active targeted component (SP94 polypeptide), the obtained WPPy@SP94 significantly increased tumor internalization and accumulation in vitro and in vivo and induced obvious DNA damage as well as robust ROS generation under X-ray irradiation, which meanwhile synergized with strong photonic hyperthermia to effectively inhibit tumor growth by single drug injection. Moreover, such biocompatible WPPy@SP94 showed negligible adverse effects on normal cells and tissues. WPPy@SP94 developed in this study not only expands the category of polypyrrole chemical syntheses but also sheds light on WPPy@SP94-based radiosensitizers for cancer RT.

Development of Porous Polyvinyl Acetate/Polypyrrole/Gallic Acid Scaffolds Using Supercritical CO2 as Tissue Regenerative Agents

Scaffolds are advanced devices employed in tissue engineering, as they are intended to mimic the characteristics of extracellular matrices. In this respect, conjugated materials are gaining relevance in the manufacturing of the foams used for therapeutic scaffolds, since they can provide certain properties that are missing in the other polymers used to form the scaffolds. This work has, therefore, focused on the development of functional scaffolds formed by conjugated-non-conjugated polymers such as polyvinyl acetate and polypyrrole, impregnated with gallic acid as the model drug and produced by means of a supercritical CO₂ foaming/impregnation process. The effects from a series of parameters such as pressure, temperature, depressurization rate, and contact time of the scaffold production process have been determined. The impregnated foams have been characterized according to their morphology, including their porosity and expansion factor, their drug loading and delivering capabilities, and their mechanical and electrical properties. The characterization of the experiments was carried out using scanning electron microscopy, liquid displacement, in vitro release, electrochemical impedance spectroscopy, and compression techniques. The results from our tests have revealed a considerable influence of all the input variables studied, as well as relevant interactions between them. Values close to 35% porosity were obtained, with a drug release of up to 10 h with a fast initial release. The best operating conditions were 353 K, 30 MPa, 0.5 MPa/min depressurization rate, and 1 h contact time. By means of the supercritical foaming/impregnation technique, scaffolds with potential in tissue engineering due to their studied properties were obtained.

Cold-atmospheric plasma augments functionalities of hybrid polymeric carriers regenerating chronic wounds: In vivo experiments

The skin possesses an epithelial barrier. Delivering growth factors to deeper wounds is usually rather challenging, and these typically restrict the therapeutic efficacy for chronic wound healing. Efficient healing of chronic wounds also requires abundant blood flow. Therefore, addressing these concerns is crucial. Among presently accessible biomedical materials, tailored hydrogels are favorable for translational medicine. However, these hydrogels display insufficient mechanical properties, hampering their biomedical uses. Cold-atmospheric plasma (CAP) has potent cross-linking/polymerizing abilities. The CAP was characterized spectroscopically to identify excited radiation and species (hydroxyl and UV). CAP was used to polymerize pyrrole (creating Ppy) and crosslink hybrid polymers (Ppy, hyaluronic acid (HA), and gelatin (GEL)) as a multimodal dressing for chronic wounds (CAP-Ppy/GEL/HA), which were used to incorporate therapeutic platelet proteins (PPs). Herein, the physicochemical and biological features of the developed CAP-Ppy/GEL/HA/PP complex were assessed. CAP-Ppy/GEL/HA/PPs had positive impacts on wound healing in vitro. In addition, the CAP-Ppy/GEL/HA complex has improved mechanical aspects, therapeutics sustained-release/retention effect, and near-infrared (NIR)-driven photothermal-hyperthermic effects on lesions that drive the expression of heat-shock protein (HSP) with anti-inflammatory properties for boosted restoration of diabetic wounds in vivo. These in vitro and in vivo outcomes support the use of CAP-Ppy/GEL/HA/PPs for diabetic wound regeneration.

Conductive Biomaterials as Bioactive Wound Dressing for Wound Healing and Skin Tissue Engineering

Conductive biomaterials based on conductive polymers, carbon nanomaterials, or conductive inorganic nanomaterials demonstrate great potential in wound healing and skin tissue engineering, owing to the similar conductivity to human skin, good antioxidant and antibacterial activities, electrically controlled drug delivery, and photothermal effect. However, a review highlights the design and application of conductive biomaterials for wound healing and skin tissue engineering is lacking. In this review, the design and fabrication methods of conductive biomaterials with various structural forms including film, nanofiber, membrane, hydrogel, sponge, foam, and acellular dermal matrix for applications in wound healing and skin tissue engineering and the corresponding mechanism in promoting the healing process were summarized. The approaches that conductive biomaterials realize their great value in healing wounds via three main strategies (electrotherapy, wound dressing, and wound assessment) were reviewed. The application of conductive biomaterials as wound dressing when facing different wounds including acute wound and chronic wound (infected wound and diabetic wound) and for wound monitoring is discussed in detail. The challenges and perspectives in designing and developing multifunctional conductive biomaterials are proposed as well.

Cold atmospheric plasma physically reinforced substances of platelets-laden photothermal-responsive methylcellulose complex restores burn wounds

Patients with irregular, huge burn wounds require time-consuming healing. The skin has an epithelial barrier mechanism. Hence, the penetration and retention of therapeutics across the skin to deep lesion is generally quite difficult and these usually constrain the delivery/therapeutic efficacies for wound healing. Effective burn wound healing also necessitates proper circulation. Conventional polymeric dressing usually exhibits weak mechanical behaviors, obstructing their load-bearing applications. Cold atmospheric plasma (CAP) was used as an efficient, environmentally friendly, and biocompatible process to crosslink methylcellulose (MC) designed for topical administration such as therapeutic substances of platelets (SP) and polyethyleneimine-polypyrrole nanoparticle (PEI-PPy NP)-laden MC hydrogel carriers, and wound dressings. The roles of framework parameters for CAP-treated SP-PEI-PPy NP-MC polymeric complex system; chemical, physical, and photothermal effects; morphological, spectroscopical, mechanical, rheological, and surface properties; in vitro drug release; and hydrophobicity are discussed. Furthermore, CAP-treated SP-PEI-PPy NP-MC polymeric complex possessed augmented mechanical properties, biocompatibility, sustainable drug release, drug-retention effects, and near-infrared (NIR)-induced hyperthermia effects that drove heat-shock protein (HSP) expression with drug permeation to deep lesions. This work sheds light on the CAP crosslinking polymeric technology and the efficacy of combining sustained drug release with photothermal therapy in burn wound bioengineering carrier designs.

Plasmonic Gold Nanoisland Film for Bacterial Theranostics

Plasmonic nanomaterials have been intensively explored for applications in biomedical detection and therapy for human sustainability. Herein, plasmonic gold nanoisland (NI) film (AuNIF) was fabricated onto a glass substrate by a facile seed-mediated growth approach. The structure of the tortuous gold NIs of the AuNIF was demonstrated by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Based on the ultraviolet-visible spectrum, the AuNIF revealed plasmonic absorption with maximum intensity at 624 nm. With the change to the surface topography created by the NIs, the capture efficiency of Escherichia coli (E. coli) by the AuNIF was significantly increased compared to that of the glass substrate. The AuNIF was applied as a surface-enhanced Raman scattering (SERS) substrate to enhance the Raman signal of E. coli. Moreover, the plasmonic AuNIF exhibited a superior photothermal effect under irradiation with simulated AM1.5 sunlight. For photothermal therapy, the AuNIF also displayed outstanding efficiency in the photothermal killing of E. coli. Using a combination of SERS detection and photothermal therapy, the AuNIF could be a promising platform for bacterial theranostics.

Gold Nanorod-Decorated Metallic MoS2 Nanosheets for Synergistic Photothermal and Photodynamic Antibacterial Therapy

Light-responsive nanocomposites have become increasingly attractive in the biomedical field for antibacterial applications. Visible-light-activated metallic molybdenum disulfide nanosheets (1T-MoS2 NSs) and plasmonic gold nanorods (AuNRs) with absorption at a wavelength of 808 nm were synthesized. AuNR nanocomposites decorated onto 1T-MoS2 NSs (MoS2@AuNRs) were successfully prepared by electrostatic adsorption for phototherapy applications. Based on the photothermal effect, the solution temperature of the MoS2@AuNR nanocomposites increased from 25 to 66.7 °C after 808 nm near-infrared (NIR) laser irradiation for 10 min. For the photodynamic effect, the MoS2@AuNR nanocomposites generated reactive oxygen species (ROS) under visible light irradiation. Photothermal therapy and photodynamic therapy of MoS2@AuNRs were confirmed against E. coli by agar plate counts. Most importantly, the combination of photothermal therapy and photodynamic therapy from the MoS2@AuNR nanocomposites revealed higher antibacterial activity than photothermal or photodynamic therapy alone. The light-activated MoS2@AuNR nanocomposites exhibited a remarkable synergistic effect of photothermal therapy and photodynamic therapy, which provides an alternative approach to fight bacterial infections.

Organic Photo-antimicrobials: Principles, Molecule Design, and Applications

The emergence of multi-drug-resistant pathogens threatens the healthcare systems world-wide. Recent advances in phototherapy (PT) approaches mediated by photo-antimicrobials (PAMs) provide new opportunities for the current serious antibiotic resistance. During the PT treatment, reactive oxygen species or heat produced by PAMs would react with the cell membrane, consequently leaking cytoplasm components and effectively eradicating different pathogens like bacteria, fungi, viruses, and even parasites. This Perspective will concentrate on the development of different organic photo-antimicrobials (OPAMs) and their application as practical therapeutic agents into therapy for local infections, wound dressings, and removal of biofilms from medical devices. We also discuss how to design highly efficient OPAMs by modifying the chemical structure or conjugating with a targeting component. Moreover, this Perspective provides a discussion of the general challenges and direction for OPAMs and what further needs to be done. It is hoped that through this overview, OPAMs can prosper and will be more widely used for microbial infections in the future, especially at a time when the global COVID-19 epidemic is getting more serious.

Biomimetic Polydopamine-Modified Silk Fibroin/Curcumin Nanofibrous Scaffolds for Chemo-photothermal Therapy of Bone Tumor

The simultaneous therapy of tumor recurrence and bone defects resulting from surgical resection of osteosarcoma is still a challenge in the clinic. Combination therapy based on a localized drug-delivery system shows great promise in the treatment of osteosarcoma. Herein, bifunctional polydopamine (PDA)-modified curcumin (CM)-loaded silk fibroin (SF) composite (SF/CM-PDA) nanofibrous scaffolds, which combined photothermal therapy with chemotherapy to synergistically enhance osteosarcoma therapy, were prepared by PDA coating of the SF/CM nanofibrous scaffolds fabricated by supercritical carbon dioxide (SC-CO₂) technology. The PDA coating improved hydrophilicity and mechanical strength of the SF/CM scaffolds. The SF/CM-PDA scaffolds present good photothermal conversion capacity and excellent photostability. The low pH and near-infrared (NIR) irradiation could effectively accelerate release of CM in the SF/CM-PDA scaffolds. The in vitro anticancer results indicated that the biocompatible SF/CM-PDA scaffolds had a long-term, stable, and superior anticancer effect compared to pure CM. Furthermore, the SF/CM-PDA scaffolds significantly increased the growth inhibition of osteosarcoma MG-63 cells under NIR irradiation (808 nm and 1.3 W/cm²). Besides, the SF/CM-PDA scaffolds could enhance osteoblast MC3T3-E1 cell proliferation in vitro when the mass ratio of CM was 0.05-0.5%. This work has therefore demonstrated that the bifunctional SF/CM-PDA scaffolds provide a competitive strategy for local osteosarcoma therapy and bone regeneration.

Antimicrobial Polymer-Based Assemblies: A Review

An antimicrobial supramolecular assembly (ASA) is conspicuous in biomedical applications. Among the alternatives to overcome microbial resistance to antibiotics and drugs, ASAs, including antimicrobial peptides (AMPs) and polymers (APs), provide formulations with optimal antimicrobial activity and acceptable toxicity. AMPs and APs have been delivered by a variety of carriers such as nanoparticles, coatings, multilayers, hydrogels, liposomes, nanodisks, lyotropic lipid phases, nanostructured lipid carriers, etc. They have similar mechanisms of action involving adsorption to the cell wall, penetration across the cell membrane, and microbe lysis. APs, however, offer the advantage of cheap synthetic procedures, chemical stability, and improved adsorption (due to multipoint attachment to microbes), as compared to the expensive synthetic routes, poor yield, and subpar in vivo stability seen in AMPs. We review recent advances in polymer-based antimicrobial assemblies involving AMPs and APs.