Synergistic chemo-/photothermal therapy based on supercritical technology-assisted chitosan-indocyanine green/luteolin nanocomposites for wound healing

Supercritical Fluid-Processed Multifunctional Hybrid Decellularized Extracellular Matrix with Chitosan Hydrogel for Improving Photoaged Dermis Microenvironment

To address the demand for reconstructive procedures in extensive subcutaneous tissue defects and significant dermis matrix loss, vascularized adipose tissue regeneration is essential for maintaining volume after material degradation. Accordingly, a double-crosslinked hydrogel that combines polyethylene glycol (PEG)-crosslinked carboxymethyl chitosan (CMC) with a hybrid decellularized extracellular matrix (dECM) is developed. The dECM, sourced from porcine adipose and cardiac tissues, processed using a supercritical fluid technique (scCO2-EtOH) retains 1.5-5-fold more angiogenic and adipogenic cytokines than that processed using traditional methods. This hybrid dECM-based filler demonstrates excellent physical properties and injectability, with injection forces being significantly less than that for crosslinked hyaluronic acid (HA) fillers. Upon incubation at 37 °C, the storage modulus of the fillers increases substantially, eventually enhancing their moldability from additional crosslinking and the thermosensitive nature of collagen. Assessments in a UVB-induced photoaging mouse model indicate that the material maintains superior shape stability, durability, and supports vascularized tissue regeneration, reduces inflammation, and enhances VEGF expression and ECM maturation more effectively compared with that using other fillers. These promising results suggest that the material can serve as a highly effective multifunctional solution for injectable regenerative medical applications and is well-suited for potential clinical trials.

Polyphenols in wound healing: unlocking prospects with clinical applications

Wound healing is a multifaceted, complex process that factors like aging, metabolic diseases, and infections may influence. The potentiality of polyphenols, natural compounds, has shown anti-inflammatory and antimicrobial properties in promoting wound healing and their potential applications in wound management. The studies reviewed indicate that polyphenols have multiple mechanisms that promote wound healing. This involves enhancing antioxidant defenses, reducing oxidative stress, modulating inflammatory responses, improving healing times, reducing infection rates, and enhancing tissue regeneration in clinical trials and in vivo and in vitro studies. Polyphenols have been proven to be effective in managing hard-to-heal wounds, especially in diabetic and elderly populations. Polyphenols have shown significant benefits in promoting angiogenesis and stimulating collagen synthesis. Polyphenol treatment has been demonstrated to have therapeutic effects in wound healing and chronic wound management. Their ability to regulate key healing processes makes them suitable for new wound care products and treatments. Future research should enhance formulations and delivery methods to optimize polyphenols' bioavailability and therapeutic efficacy in wound management approaches.

Nanomaterials at the forefront of antimicrobial therapy by photodynamic and photothermal strategies

In the face of the increasing resistance of microorganisms to traditional antibiotics, the development of innovative treatment methods is becoming increasingly urgent. Nanophototherapy technology can precisely target the infected area and achieve synergistic antibacterial effects in multiple modes. This phototherapy method has shown significant efficacy in treating diseases caused by drug-resistant bacteria, especially in the elimination of biofilms, where it has demonstrated strong dissolution capabilities. PTT utilizes photothermal agents to convert near-infrared light into heat, effectively killing bacteria and promoting tissue regeneration. Similarly, PDT utilizes photosensitizers, which produce reactive oxygen species (ROS) when activated by light, destroying the structure and function of bacterial cells. This review summarizes photothermal agents and photosensitizers used for antibacterial purposes. In conducting our literature review, we employed a systematic approach to ensure a comprehensive and representative selection of studies. Additionally, this article explores the potential of phototherapy in regulating wound microenvironments, promoting wound healing, and activating the immune system. Nanophototherapeutic materials show great potential for application in antibacterial treatment and are expected to provide innovative solutions for drug-resistant bacterial infections that traditional antibiotics are struggling to address.

Broad-Spectrum Bactericidal Multifunctional Tiny Silicon-Based Nanoparticles Modified with Tannic Acid for Healing Infected Diabetic Wounds

Infected chronic wounds, in particular, diabetic wounds, are hard to heal, posing a global health concern with high morbidity and mortality rates. Diabetic full-thickness wounds infected with E. coli belong to the most difficult to heal chronic infected wounds. Here, we introduced tannic acid-modified silicon-based nanoparticles (TA-SiNPs) with broad-spectrum bactericidal activity that bacteria develop minimal resistance to, and they can effectively treat full-thickness wounds in diabetic mice infected with E. coli. Our findings indicate that these TA-SiNPs could achieve 100% antibacterial efficiency against S. aureus and 99.83% against E. coli, underlied by a positive surface charge and tannic acid groups facilitating bacterial membrane chemical composition depletion and depolarization of the membrane. In addition, we showed that spraying TA-SiNPs onto the skin wound of diabetic mice infected with E. coli resulted in wound healing with 98% closure after 12 days, in stark contrast to 49% of the control (PBS) and 68% of the one treated with Ofloxacin. Along with infection inhibition and ROS scavenging, we identified cell proliferation stimulation, inflammatory cytokine downregulation, and healing cytokine upregulation in the lesion, favoring the healing process. This study not only demonstrates the feasibility of employing silicon-based nanoparticles in diabetic wound healing for the first time, but also reports the first broad-spectrum bactericidal silicon nanodots. Furthermore, this provides novel insights into the mechanism of tannin-based nanoparticles disrupting bacterial membranes by depleting their chemical constituents. Our results highlighted that the developed TA-SiNPs are an effective nanomaterial for treating the infected chronic wounds.

Inhalable Polymeric Microparticles for Phage and Photothermal Synergistic Therapy of Methicillin-Resistant Staphylococcus aureus Pneumonia

Acute methicillin-resistant Staphylococcus aureus (MRSA) pneumonia is a common and serious lung infection with high morbidity and mortality rates. Due to the increasing antibiotic resistance, toxicity, and pathogenicity of MRSA, there is an urgent need to explore effective antibacterial strategies. In this study, we developed a dry powder inhalable formulation which is composed of porous microspheres prepared from poly(lactic-co-glycolic acid) (PLGA), internally loaded with indocyanine green (ICG)-modified, heat-resistant phages that we screened for their high efficacy against MRSA. This formulation can deliver therapeutic doses of ICG-modified active phages to the deep lung tissue infection sites, avoiding rapid clearance by alveolar macrophages. Combined with the synergistic treatment of phage therapy and photothermal therapy, the formulation demonstrates potent bactericidal effects in acute MRSA pneumonia. With its long-term stability at room temperature and inhalable characteristics, this formulation has the potential to be a promising drug for the clinical treatment of MRSA pneumonia.

Phytic Acid-Promoted Deposition of Gold Nanoparticles with Grafted Cationic Polymer Brushes for the Construction of Synergistic Contact-Killing and Photothermal Bactericidal Coatings

Medical implants are constantly facing the risk of bacterial infections, especially infections caused by multidrug resistant bacteria. To mitigate this problem, gold nanoparticles with alkyl bromide moieties (Au NPs-Br) on the surfaces were prepared. Xenon light irradiation triggered the plasmon effect of Au NPs-Br to induce free radical graft polymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA), leading to the formation of poly(DMAEMA) brush-grafted Au NPs (Au NPs-g-PDM). The Au NPs-g-PDM nanocomposites were conjugated with phytic acid (PA) via electrostatic interaction and van der Waals interaction. The as-formed aggregates were deposited on the titanium (Ti) substrates to form the PA/Au NPs-g-PDM (PAP) hybrid coatings through surface adherence of PA and the gravitational effect. Synergistic bactericidal effects of contact-killing caused by the cationic PDM brushes, and local heating generated by the Au NPs under near-infrared irradiation, conferred strong antibacterial effects on the PAP-deposited Ti (Ti-PAP) substrates. The synergistic bactericidal effects reduced the threshold temperature required for the photothermal sterilization, which in turn minimized the secondary damage to the implant site. The Ti-PAP substrates exhibited 97.34% and 99.97% antibacterial and antiadhesive efficacy, respectively, against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), compared to the control under in vitro antimicrobial assays. Furthermore, the as-constructed Ti-PAP surface exhibited a 99.42% reduction in the inoculated S. aureus under in vivo assays. In addition, the PAP coatings exhibited good biocompatibility in the hemolysis and cytotoxicity assays as well as in the subcutaneous implantation of rats.

The development of nanocarriers for natural products

Natural bioactive compounds from plants exhibit substantial pharmacological potency and therapeutic value. However, the development of most plant bioactive compounds is hindered by low solubility and instability. Conventional pharmaceutical forms, such as tablets and capsules, only partially overcome these limitations, restricting their efficacy. With the recent development of nanotechnology, nanocarriers can enhance the bioavailability, stability, and precise intracellular transport of plant bioactive compounds. Researchers are increasingly integrating nanocarrier-based drug delivery systems (NDDS) into the development of natural plant compounds with significant success. Moreover, natural products benefit from nanotechnological enhancement and contribute to the innovation and optimization of nanocarriers via self-assembly, grafting modifications, and biomimetic designs. This review aims to elucidate the collaborative and reciprocal advancement achieved by integrating nanocarriers with botanical products, such as bioactive compounds, polysaccharides, proteins, and extracellular vesicles. This review underscores the salient challenges in nanomedicine, encompassing long-term safety evaluations of nanomedicine formulations, precise targeting mechanisms, biodistribution complexities, and hurdles in clinical translation. Further, this study provides new perspectives to leverage nanotechnology in promoting the development and optimization of natural plant products for nanomedical applications and guiding the progression of NDDS toward enhanced efficiency, precision, and safety. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Disruption of Communication: Recent Advances in Antibiofilm Materials with Anti-Quorum Sensing Properties

Biofilm contamination presents a significant threat to public health, the food industry, and aquatic/marine-related applications. In recent decades, although various methods have emerged to combat biofilm contamination, the intricate and persistent nature of biofilms makes complete eradication challenging. Therefore, innovative alternative solutions are imperative for addressing biofilm formation. Instead of solely focusing on the eradication of mature biofilms, strategically advantageous measures involve the delay or prevention of biofilm formation on surfaces. Quorum sensing, a communication system enabling bacteria to coordinate their behavior based on population density, plays a pivotal role in biofilm formation for numerous microbial species. Materials possessing antibiofilm properties that target quorum sensing have gained considerable attention for their potential to prevent biofilm formation. This Review consolidates recent research progress on the utilization of materials with antiquorum sensing properties for combating biofilm formation. These materials can be categorized into three distinct types: (i) antibiofilm nanomaterials, (ii) antibiofilm surfaces, and (iii) antibiofilm hydrogels with antiquorum sensing capabilities. Finally, the Review concludes with a brief discussion of current challenges and outlines potential avenues for future research.

Application of metal-organic frameworks-based functional composite scaffolds in tissue engineering

With the rapid development of materials science and tissue engineering, a variety of biomaterials have been used to construct tissue engineering scaffolds. Due to the performance limitations of single materials, functional composite biomaterials have attracted great attention as tools to improve the effectiveness of biological scaffolds for tissue repair. In recent years, metal-organic frameworks (MOFs) have shown great promise for application in tissue engineering because of their high specific surface area, high porosity, high biocompatibility, appropriate environmental sensitivities and other advantages. This review introduces methods for the construction of MOFs-based functional composite scaffolds and describes the specific functions and mechanisms of MOFs in repairing damaged tissue. The latest MOFs-based functional composites and their applications in different tissues are discussed. Finally, the challenges and future prospects of using MOFs-based composites in tissue engineering are summarized. The aim of this review is to show the great potential of MOFs-based functional composite materials in the field of tissue engineering and to stimulate further innovation in this promising area.

Recent advances in fabrication of dECM-based composite materials for skin tissue engineering

Chronic wound management is an intractable medical and social problem, affecting the health of millions worldwide. Decellularized extracellular matrix (dECM)-based materials possess remarkable biological properties for tissue regeneration, which have been used as commercial products for skin regeneration in clinics. However, the complex external environment and the longer chronic wound-healing process hinder the application of pure dECM materials. dECM-based composite materials are constructed to promote the healing process of different wounds, showing noteworthy functions, such as anti-microbial activity and suitable degradability. Moreover, fabrication technologies for designing wound dressings with various forms have expanded the application of dECM-based composite materials. This review provides a summary of the recent fabrication technologies for building dECM-based composite materials, highlighting advances in dECM-based molded hydrogels, electrospun fibers, and bio-printed scaffolds in managing wounds. The associated challenges and prospects in the clinical application of dECM-based composite materials for wound healing are finally discussed.

Nano-scale drug delivery systems for luteolin: advancements and applications

Luteolin (Lu) is a naturally occurring flavonoid compound with a diverse array of pharmacological activities, including anti-tumor, anti-inflammatory, antibacterial, and neuroprotective properties. However, the therapeutic efficacy and clinical application of Lu are significantly hindered by inherent limitations, such as poor water solubility, short half-life, low bioavailability, and potential off-target toxicity. Recent studies have demonstrated that the utilization of nanocarriers presents a promising strategy to enhance the solubility of Lu, prolong its circulation time, and improve its targeting ability. Despite numerous reviews over the past few decades having focused on the source, pharmacological activities, and molecular mechanisms of Lu, there exists a conspicuous gap in the literature regarding a comprehensive review of Lu-loaded nanoformulations and their applications. To address this gap, we present an exhaustive overview of the advancements and applications of nano-scale drug delivery systems specifically designed for Lu. These platforms encompass micelles, nanocarrier-based systems, emulsified drug delivery systems, and vesicular drug delivery systems. We provide detailed insights into the synthetic materials, preparation methods, physicochemical properties, and significant outcomes associated with these nanoformulations. This systematic review will be particularly valuable to researchers seeking novel avenues in the field of nano-delivery strategies and exploring the potential clinical applications of Lu.

Decellularized extracellular matrix-based composite scaffolds for tissue engineering and regenerative medicine

Despite the considerable advancements in fabricating polymeric-based scaffolds for tissue engineering, the clinical transformation of these scaffolds remained a big challenge because of the difficulty of simulating native organs/tissues' microenvironment. As a kind of natural tissue-derived biomaterials, decellularized extracellular matrix (dECM)-based scaffolds have gained attention due to their unique biomimetic properties, providing a specific microenvironment suitable for promoting cell proliferation, migration, attachment and regulating differentiation. The medical applications of dECM-based scaffolds have addressed critical challenges, including poor mechanical strength and insufficient stability. For promoting the reconstruction of damaged tissues or organs, different types of dECM-based composite platforms have been designed to mimic tissue microenvironment, including by integrating with natural polymer or/and syntenic polymer or adding bioactive factors. In this review, we summarized the research progress of dECM-based composite scaffolds in regenerative medicine, highlighting the critical challenges and future perspectives related to the medical application of these composite materials.

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.

Sonodynamic therapy-based nanoplatforms for combating bacterial infections

The rapid spread and uncontrollable evolution of antibiotic-resistant bacteria have already become urgent global to treat bacterial infections. Sonodynamic therapy (SDT), a noninvasive and effective therapeutic strategy, has broadened the way toward dealing with antibiotic-resistant bacteria and biofilms, which base on ultrasound (US) with sonosensitizer. Sonosensitizer, based on small organic molecules or inorganic nanoparticles, is essential to the SDT process. Thus, it is meaningful to design a sonosensitizer-loaded nanoplatform and synthesize the nanoplatform with an efficient SDT effect. In this review, we initially summarize the probable SDT-based antibacterial mechanisms and systematically discuss the current advancement in different SDT-based nanoplatform (including nanoplatform for organic small-molecule sonosensitizer delivery and nanoplatform as sonosensitizer) for bacterial infection therapy. In addition, the biomedical applications of SDT-involved multifunctional nanoplatforms are also discussed. We believe the innovative SDT-based nanoplatforms would become a highly efficient next-generation noninvasive therapeutic tool for combating bacterial infection.

Fabrication of chitosan/phenylboronic acid/SiO2 hydrogel composite silk fabrics for enhanced adsorption and controllable release on luteolin

Due to the growing demand for self-health and safety, eco-friendly health textile products with natural colors and pharmacological functionalities have gained considerable popularity. Rapid adsorption and controlled release of active molecules are important issues for functional health textiles. In this study, a functionalized chitosan-based hydrogel composite silk fabric was prepared using chitosan, 3-carboxyphenylboronic acid, and 3-(2, 3-epoxypropyl oxygen) propyl silane by dip-pad and vacuum freeze-drying techniques. The results showed that the incorporation of chitosan/phenylboronic/SiO2 hydrogel into silk fibers improved the UV protection capacity, mechanical properties, and adsorption properties of silk fabrics. The effects of various parameters on the luteolin adsorption properties of silk fabrics were discussed, including metal salt types, salt dosage, pH value, dyeing temperature, initial luteolin concentration, and dyeing time. Under the dyeing temperature of 60 °C and pH of 6.8, the luteolin exhaustion of the composite silk was more than that of the untreated silk, and the adsorption process followed the quasi-second-order kinetic model and the Langmuir adsorption isotherm model. Furthermore, the luteolin-dyed composite silk materials exhibited strong antioxidant activity and controllable release behavior with various pH levels. The as-prepared chitosan-hydrogel composite silk could be a promising material for the sustained release of drugs in medical and healthcare textiles.

Research hotspot and trend of chronic wounds: A bibliometric analysis from 2013 to 2022

Chronic wounds have been confirmed as a vital health problem facing people in the global population aging process. While significant progress has been achieved in the study of chronic wounds, the treatment effect should be further improved. The number of publications regarding chronic wounds has been rising rapidly. In this study, bibliometric analysis was conducted to explore the hotspots and trends in the research on chronic wounds. All relevant studies on chronic wounds between 2013 and 2022 were collected from the PubMed database of the Web of Science (WOS) and the National Center for Biotechnology Information (NCBI). The data were processed and visualised using a series of software. On that basis, more insights can be gained into hotspots and trends of this research field. Wound Repair and Regeneration has the highest academic achievement in the field of chronic wound research. The United States has been confirmed as the most productive country, and the University of California System ranks high among other institutions. Augustin, M. is the author of the most published study, and Frykberg, RG et al. published the most cited study. Furthermore, the hotspots of wound research over the last decade were identified (e.g., bandages, infection and biofilms, pathophysiology and therapy). This study will help researchers gain insights into chronic wound research's hotspots and trends accurately and quickly. Moreover, the exploration of bacterial biofilm and the pathophysiological mechanism of the chronic wound will lay a solid foundation and clear direction for treating chronic wounds.

NIR-responsive carrier-free nanoparticles based on berberine hydrochloride and indocyanine green for synergistic antibacterial therapy and promoting infected wound healing

Bacterial infections cause severe health conditions, resulting in a significant economic burden for the public health system. Although natural phytochemicals are considered promising anti-bacterial agents, they suffer from several limitations, such as poor water solubility and low bioavailability in vivo, severely restricting their wide application. Herein, we constructed a near-infrared (NIR)-responsive carrier-free berberine hydrochloride (BH, phytochemicals)/indocyanine green (ICG, photosensitizer) nanoparticles (BI NPs) for synergistic antibacterial of an infected wound. Through electrostatic interaction and π-π stacking, the hydrophobic BH and amphiphilic ICG are initially self-assembled to generate carrier-free nanoparticles. The obtained BI NPs demonstrated NIR-responsive drug release behavior and better photothermal conversion efficiency of up to 36%. In addition, BI NPs stimulated by NIR laser exhibited remarkable antibacterial activity, which realized the synergistic antibacterial treatment and promoted infected wound healing. In summary, the current research results provided a candidate strategy for self-assembling new BI NPs to treat bacterial infections synergistically.

Aggregation-induced emission biomaterials for anti-pathogen medical applications: detecting, imaging and killing

Microbial pathogens, including bacteria, fungi and viruses, greatly threaten the global public health. For pathogen infections, early diagnosis and precise treatment are essential to cut the mortality rate. The emergence of aggregation-induced emission (AIE) biomaterials provides an effective and promising tool for the theranostics of pathogen infections. In this review, the recent advances about AIE biomaterials for anti-pathogen theranostics are summarized. With the excellent sensitivity and photostability, AIE biomaterials have been widely applied for precise diagnosis of pathogens. Besides, different types of anti-pathogen methods based on AIE biomaterials will be presented in detail, including chemotherapy and phototherapy. Finally, the existing deficiencies and future development of AIE biomaterials for anti-pathogen applications will be discussed.

Natural Compounds and Biopolymers-Based Hydrogels Join Forces to Promote Wound Healing

Rapid and complete wound healing is a clinical emergency, mainly in pathological conditions such as Type 2 Diabetes mellitus. Many therapeutic tools are not resolutive, and the research for a more efficient remedial remains a challenge. Wound dressings play an essential role in diabetic wound healing. In particular, biocompatible hydrogels represent the most attractive wound dressings due to their ability to retain moisture as well as ability to act as a barrier against bacteria. In the last years, different functionalized hydrogels have been proposed as wound dressing materials, showing encouraging outcomes with great benefits in the healing of the diabetic wounds. Specifically, because of their excellent biocompatibility and biodegradability, natural bioactive compounds, as well as biomacromolecules such as polysaccharides and protein, are usually employed in the biomedical field. In this review, readers can find the main discoveries regarding the employment of naturally occurring compounds and biopolymers as wound healing promoters with antibacterial activity. The emerging approaches and engineered devices for effective wound care in diabetic patients are reported and deeply investigated.