Water-stable zirconium-based metal-organic frameworks armed polyvinyl alcohol nanofibrous membrane with enhanced antibacterial therapy for wound healing

Antimicrobial and antibiofilm activity of prepared thymol@UIO-66 and thymol/ZnONPs@UIO-66 nanoparticles against Methicillin-resistant Staphylococcus aureus: A synergistic approach

This study introduces a novel approach to enhance the antibacterial properties of UIO-66 by incorporating both Thymol and ZnO nanoparticles within its framework which represents a significant advancement like exhibiting a synergistic antibacterial effect, providing a prolonged and controlled release, and mitigating cytotoxicity associated with the release of free ZnO nanoparticles by combining these two antimicrobial agents within a single, well-defined metal-organic framework. UIO-66 frameworks are investigated as carriers for the natural antimicrobial agent, Thymol, and ZnONPs offering a novel drug delivery system for antibacterial applications. Results demonstrated 132, 90, 184, and 223 nm sizes for UIO-66, ZnONPs, UIO-66 encapsulated Thymol, and UIO-66 encapsulated both Thymol and ZnONPs, respectively. Successful encapsulation of the antibacterial drug with a high entrapment efficiency of 64 % for Thymol was approved, and 49 % in-vitro release of Thymol was achieved for 72 hours. In-vitro antibacterial assays revealed promising results, with the drug-loaded nanoparticles exhibiting significantly lower MIC values and enhanced bactericidal activity against S. Aureus bacterial strains compared to the free drug, as demonstrated by agar disk diffusion and time-kill assays. MIC values reduced from a range of 31.25-250 µg/ml for free Thymol and 12.5-100 µg/ml for free ZnONPs to 3.9-62.5 µg/ml for Thymol@UIO-66 and 1.95-15.63 µg/ml for Thymol/ZnONPs@UIO-66. According to the results, the mixture of both Thymol and ZnONPs had 41 % and 16 % more antibiofilm activities in comparison with free Thymol and free ZnONPs, respectively. Furthermore, Thymol@UIO-66 had 25 % higher antibiofilm activities relative to not-encapsulated Thymol and ZnONPs, and this improvement was even 46 % more in Thymol/ZnONPs@UIO-66 in comparison with Thymol@UIO-66. Overall, this study demonstrates the potential of Thymol/ZnONPs@UIO-66 frameworks as a promising drug delivery platform for effective antibacterial therapy. This approach to overcome antibiotic resistance and improve treatment efficacy potentially.

Electrospun nanofibrous membranes meet antibacterial nanomaterials: From preparation strategies to biomedical applications

Electrospun nanofibrous membranes (eNFMs) have been extensively developed for bio-applications due to their structural and compositional similarity to the natural extracellular matrix. However, the emergence of antibiotic resistance in bacterial infections significantly impedes the further development and applications of eNFMs. The development of antibacterial nanomaterials substantially nourishes the engineering design of antibacterial eNFMs for combating bacterial infections without relying on antibiotics. Herein, a comprehensive review of diverse fabrication techniques for incorporating antibacterial nanomaterials into eNFMs is presented, encompassing an exhaustive introduction to various nanomaterials and their bactericidal mechanisms. Furthermore, the latest achievements and breakthroughs in the application of these antibacterial eNFMs in tissue regenerative therapy, mainly focusing on skin, bone, periodontal and tendon tissues regeneration and repair, are systematically summarized and discussed. In particular, for the treatment of skin infection wounds, we highlight the antibiotic-free antibacterial therapy strategies of antibacterial eNFMs, including (i) single model therapies such as metal ion therapy, chemodynamic therapy, photothermal therapy, and photodynamic therapy; and (ii) multi-model therapies involving arbitrary combinations of these single models. Additionally, the limitations, challenges and future opportunities of antibacterial eNFMs in biomedical applications are also discussed. We anticipate that this comprehensive review will provide novel insights for the design and utilization of antibacterial eNFMs in future research.

Lignin-Derived Gold-Titanium Dioxide Nanophotocomposites as Potent Photoactivatable Probes for Microbial Inactivation

The overuse of antibiotics has accelerated antibiotic resistance, and it is a significant global threat to public health. To combat the rising threat of drug-resistant microbes, antimicrobial photodynamic therapy (APDT) has emerged as a promising alternative therapeutic strategy. This study focuses on the synthesis of eco-friendly lignin-derived gold-titanium dioxide nanophotocomposites (L@Au-TiO2 NCs). Lignin was utilized as a sustainable precursor for the synthesis of L@Au-TiO2 NCs. The gold and TiO2 nanoparticles possess inherent photodynamic properties, and thus the developed L@Au-TiO2 NCs exhibit enhanced antimicrobial efficacy due to the synergistic combination of their attributes. The antimicrobial potential of the L@Au-TiO2 NCs was evaluated against various microbial strains (Escherichia coli, Bacillus megaterium, and Candida tropicalis) under dark and green light conditions. The outcome of this study highlights the promising potential of L@Au-TiO2 NCs for photodynamic antimicrobial applications. The L@Au-TiO2 nanophotocomposites could be explored in the fields of medicine and nanotechnology to introduce innovative ideas into the biomedical field.

Antibacterial Hydrogels for Wound Dressing Applications: Current Status, Progress, Challenges, and Trends

Bacterial infection treatment for chronic wounds has posed a major medical threat and challenge. Bacteria at the wounded sites can compete with the immune system and subsequently invade live tissues, leading to more severe tissue damage. Therefore, there is an urgent demand for wound dressings with antibacterial and anti-inflammatory properties. Considering the concept of moist healing, hydrogels with a three-dimensional (3D) network structure are widely used as wound dressings due to their excellent hydrophilicity, water retention properties, and biocompatibility. Developing antibacterial hydrogels for the treatment of infected wounds has been receiving extensive attention recently. This article categorizes antibacterial hydrogels according to their materials and antibacterial modes, and introduces the recent findings and progress regarding their status. More importantly, with the development of emerging technologies, new therapies are utilized to prepare antibacterial hydrogels such as nanoenzymes, photothermal therapy (PTT), photodynamic therapy (PDT), metal-organic frameworks (MOFs), and other external stimuli-responsive methods. Therefore, this review also examines their progress, challenges, and future trends as wound dressings. In the following studies, there will still be a focus on antibacterial hydrogels that have a high performance, multi-functions, and intelligence, especially biocompatibility, a high and long-lasting antibacterial property, responsiveness, and on-demand therapeutic ability.

A ZIF-8-encapsulated interpenetrated hydrogel/nanofiber composite patch for chronic wound treatment

Designing wound dressings necessitates the crucial considerations of maintaining a moist environment and implementing effective bacterial control. Furthermore, developing a three-dimensional framework emulating the extracellular matrix (ECM) confers advantages in fostering cellular migration and proliferation. Inspired by this, hydrogel/nanofiber composites have been demonstrated as promising materials for wound dressings. The composites also overcome the disadvantages of poor mechanical properties and rapid release of traditional pure hydrogels. In this study, we constructed a calcium alginate hydrogel/polylactic acid nanofiber (CAH/PLANF) composite with an interpenetrated network. Additionally, the synthesis of zeolitic imidazolate framework-8 (ZIF-8) incorporated into the composite system endowed the system with enhanced mechanical properties and photodynamic antibacterial attributes. The obtained composite patch (ZIF-8@CAH/PLANF) exhibited excellent swelling, strong mechanical properties, low cytotoxicity, and durable photodynamic antibacterial effect with an antibacterial efficacy of higher than 99.99%. Finally, bacterial infection and wound healing properties were investigated in vivo, and the ZIF-8@CAH/PLANF patch was proven to have the ability to fight infection and accelerate wound healing.

2D nanomaterial-based 3D network hydrogels for anti-infection therapy

Two-dimensional nanomaterials (2D NMs) refer to nanomaterials that possess a planar topography with a thickness of one or several atomic layers. Due to their large specific surface areas, atomic thickness, rough edges, and electron confinement in two dimensions, they have emerged as promising antimicrobial agents over antibiotics in combating bacterial infections. However, 2D NMs encounter issues such as low bio-safety, easy aggregation, and limited tissue penetration efficiency. To address these concerns, hydrogels with three-dimensional (3D) networks have been developed to encapsulate 2D NMs, aiming to enhance their biocompatibility, biodegradability, and ability to regulate and remodel the tissue microenvironment at the infected site. This review systematically summarizes the current studies on 2D NM-based antibacterial hydrogels with 3D network structures (named 2N3Hs). Firstly, we introduce the emerging types of 2N3Hs and describe their antibacterial actions. Subsequently, we discuss the applications of 2N3Hs in three biomedical fields, including wound dressing, cancer treatment, and bone regeneration. Finally, we conclude the review with current challenges and future developments for 2N3Hs, highlighting their potential as a promising choice for next-generation biomedical devices, particularly in the field of tissue engineering and regenerative medicine. This review aims to provide a comprehensive and panoramic overview of anti-infective 2N3Hs for various biomedical applications.

Functionalization strategies of metal-organic frameworks for biomedical applications and treatment of emerging pollutants: A review

One of the representative coordination polymers, metal-organic frameworks (MOFs) material, is of hotspot interest in the multi field thanks to their unique structural characteristics and properties. As a novel hierarchical structural class, MOFs show diverse topologies, intrinsic behaviors, flexibility, etc. However, bare MOFs have less desirable biofunction, high humid sensitivity and instability in water, restraining their efficiencies in biomedical and environmental applications. Thus, a structural modification is required to address such drawbacks. Herein, we pinpoint new strategies in the synthesis and functionalization of MOFs to meet demanding requirements in in vitro tests, i.e., antibacterial face masks against corona virus infection and in wound healing and nanocarriers for drug delivery in anticancer. Regarding the treatment of wastewater containing emerging pollutants such as POPs, PFAS, and PPCPs, functionalized MOFs showed excellent performance with high efficiency and selectivity. Challenges in toxicity, vast database of clinical trials for biomedical tests and production cost can be still presented. MOFs-based composites can be, however, a bright candidate for reasonable replacement of traditional nanomaterials in biomedical and wastewater treatment applications.

Super-wetting and self-cleaning polyvinyl alcohol/sodium alginate nanofiber membrane decorated with MIL-88A(Fe) for efficient oil/water emulsion separation and dye degradation

Membrane separation is considered an effective approach to water purification. Nevertheless, membrane fouling dramatically decreases the separation efficiency and lifetime of membranes, thus limiting its further development and application. Herein, a multifunctional self-cleaning MIL-88A(Fe) decorated polyvinyl alcohol/sodium alginate (MIL-88A(Fe)@PVA-SA) nanofiber membrane was prepared by electrospinning and in-situ growth methods for the separation of oil/water emulsions and photo-Fenton degradation of dyes. The membrane possesses superhydrophilicity with a water contact angle (WCA) of 0° and superoleophobicity with underwater oil contact angle (UCA) of 161.7°, and exhibits superior separation efficiency (>99.5 %) and permeation flux (1140-2455 L/m2/h) for different oil/water emulsions. Moreover, the membrane exhibited an outstanding photo-Fenton performance under visible light, with degradation efficiencies (~99.9 %) towards methylene blue (MB) and reactive red 24 (RR24) within 90 min. Importantly, the membrane can be easily regenerated by simple rinsing and photo-Fenton self-cleaning treatment. In this study, MIL-88A(Fe)@PVA-SA nanofiber membrane has a promising application in dye removal and oil/water separation, providing a new idea to develop novel membrane materials.

Metal-organic gels: recent advances in their classification, characterization, and application in the pharmaceutical field

Metal-organic gels (MOGs) are a type of functional soft substance with a three-dimensional (3D) network structure and solid-like rheological behavior, which are constructed by metal ions and bridging ligands formed under the driving force of coordination interactions or other non-covalent interactions. As the homologous substances of metal-organic frameworks (MOFs) and gels, they exhibit the potential advantages of high porosity, flexible structure, and adjustable mechanical properties, causing them to attract extensive research interest in the pharmaceutical field. For instance, MOGs are often used as excellent vehicles for intelligent drug delivery and programmable drug release to improve the clinical curative effect with reduced side effects. Also, MOGs are often applied as advanced biomedical materials for the repair and treatment of pathological tissue and sensitive detection of drugs or other molecules. However, despite the vigorous research on MOGs in recent years, there is no systematic summary of their applications in the pharmaceutical field to date. The present review systematically summarize the recent research progress on MOGs in the pharmaceutical field, including drug delivery systems, drug detection, pharmaceutical materials, and disease therapies. In addition, the formation principles and classification of MOGs are complemented and refined, and the techniques for the characterization of the structures/properties of MOGs are overviewed in this review.

Magnetic UiO-66-NH2 Core-Shell Nanohybrid as a Promising Carrier for Quercetin Targeted Delivery toward Human Breast Cancer Cells

In this study, a magnetic core-shell metal-organic framework (MOF) nanocomposite, Fe3O4-COOH@UiO-66-NH2, was synthesized for tumor-targeting drug delivery by incorporating carboxylate groups as functional groups onto ferrite nanoparticle surfaces, followed by fabrication of the UiO-66-NH2 shell using a facile self-assembly approach. The anticancer drug quercetin (QU) was loaded into the magnetic core-shell nanoparticles. The synthesized magnetic nanoparticles were comprehensively evaluated through multiple techniques, including FT-IR, PXRD, FE-SEM, TEM, EDX, BET, UV-vis, ZP, and VSM. Drug release investigations were conducted to investigate the release behavior of QU from the nanocomposite at two different pH values (7.4 and 5.4). The results revealed that QU@Fe3O4-COOH@UiO-66-NH2 exhibited a high loading capacity of 43.1% and pH-dependent release behavior, maintaining sustained release characteristics over a prolonged duration of 11 days. Furthermore, cytotoxicity assays using the human breast cancer cell line MDA-MB-231 and the normal cell line HEK-293 were performed to evaluate the cytotoxic effects of QU, UiO-66-NH2, Fe3O4-COOH, Fe3O4-COOH@UiO-66-NH2, and QU@Fe3O4-COOH@UiO-66-NH2. Treatment with QU@Fe3O4-COOH@UiO-66-NH2 substantially reduced the cell viability in cancerous MDA-MB-231 cells. Cellular uptake and cell death mechanisms were further investigated, demonstrating the internalization of QU@Fe3O4-COOH@UiO-66-NH2 by cancer cells and the induction of cancer cell death through the apoptosis pathway. These findings highlight the considerable potential of Fe3O4-COOH@UiO-66-NH2 as a targeted nanocarrier for the delivery of anticancer drugs.

Drug cross-linking electrospun fiber for effective infected wound healing

The management of infected wounds is still an intractable challenge in clinic. Development of antibacterial wound dressing is of great practical significance for wound management. Herein, a natural-derived antibacterial drug, tannic acid (TA), was incorporated into the electrospun polyvinyl alcohol (PVA) fiber (TA/PVA fiber, 952 ± 40 nm in diameter). TA worked as a cross-linker via hydrogen bonding with PVA to improve the physicochemical properties of the fiber and to reach a sustained drug release (88% release of drug at 48 h). Improved mechanical property (0.8-1.2 MPa) and computational simulation validated the formation of the hydrogen bonds between TA and PVA. Moreover, the antibacterial and anti-inflammatory characteristics of TA laid the foundation for the application of TA/PVA fiber in repairing infected wounds. Meanwhile, in vitro studies proved the high hemocompatibility and cytocompatibility of TA/PVA fiber. Further in vivo animal investigation showed that the TA/PVA fiber promoted the repair of infected wound by inhibiting the bacterial growth, promoting granulation formation, and collagen matrix deposition, accelerating angiogenesis, and inducing M2 macrophage polarization within 14 days. All the data demonstrated that the TA cross-linked fiber would be a potent dressing for bacteria-infected wound healing.

Metal-Organic Framework/Polyvinyl Alcohol Composite Films for Multiple Applications Prepared by Different Methods

The incorporation of different functional fillers has been widely used to improve the properties of polymeric materials. The polyhydroxy structure of PVA with excellent film-forming ability can be easily combined with organic/inorganic multifunctional compounds, and such an interesting combining phenomenon can create a variety of functional materials in the field of materials science. The composite membrane material obtained by combining MOF material with high porosity, specific surface area, and adjustable structure with PVA, a non-toxic and low-cost polymer material with good solubility and biodegradability, can combine the processability of PVA with the excellent performance of porous filler MOFs, solving the problem that the poor machinability of MOFs and the difficulty of recycling limit the practical application of powdered MOFs and improving the physicochemical properties of PVA, maximizing the advantages of the material to develop a wider range of applications. Firstly, we systematically summarize the preparation of MOF/PVA composite membrane materials using solution casting, electrostatic spinning, and other different methods for such excellent properties, in addition to discussing in detail the various applications of MOF/PVA composite membranes in water treatment, sensing, air purification, separation, antibacterials, and so on. Finally, we conclude with a discussion of the difficulties that need to be overcome during the film formation process to affect the performance of the composite film and offer encouraging solutions.

Recent Advances on Membranes for Water Purification Based on Carbon Nanomaterials

Every year the problem of water purification becomes more relevant. This is due to the continuous increase in the level of pollution of natural water sources, an increase in the population, and sharp climatic changes. The growth in demand for affordable and clean water is not always comparable to the supply that exists in the water treatment market. In addition, the amount of water pollution increases with the increase in production capacity, the purification of which cannot be fully handled by conventional processes. However, the application of novel nanomaterials will enhance the characteristics of water treatment processes which are one of the most important technological problems. In this review, we considered the application of carbon nanomaterials in membrane water purification. Carbon nanofibers, carbon nanotubes, graphite, graphene oxide, and activated carbon were analyzed as promising materials for membranes. The problems associated with the application of carbon nanomaterials in membrane processes and ways to solve them were discussed. Their efficiency, properties, and characteristics as a modifier for membranes were analyzed. The potential directions, opportunities and challenges for application of various carbon nanomaterials were suggested.

Application of Metal–Organic Framework in Diagnosis and Treatment of Diabetes

Diabetes-related chronic wounds are often accompanied by a poor wound-healing environment such as high glucose, recurrent infections, and inflammation, and standard wound treatments are fairly limited in their ability to heal these wounds. Metal–organic frameworks (MOFs) have been developed to improve therapeutic outcomes due to their ease of engineering, surface functionalization, and therapeutic properties. In this review, we summarize the different synthesis methods of MOFs and conduct a comprehensive review of the latest research progress of MOFs in the treatment of diabetes and its wounds. State-of-the-art in vivo oral hypoglycemic strategies and the in vitro diagnosis of diabetes are enumerated and different antimicrobial strategies (including physical contact, oxidative stress, photothermal, and related ions or ligands) and provascular strategies for the treatment of diabetic wounds are compared. It focuses on the connections and differences between different applications of MOFs as well as possible directions for improvement. Finally, the potential toxicity of MOFs is also an issue that we cannot ignore.

Tailoring biocompatibility of composite scaffolds of collagen/guar gum with metal-organic frameworks

Metal-organic frameworks (MOFs) are microporous materials with high potential for biomedical applications. They are useful as drug delivery systems, antibacterials, and biosensors. Recently, composite materials comprised of polymer matrixes and MOFs have gained relevance in the biomedical field due to their high potential as materials to accelerate wound healing. In this work, we studied the potential applications of composite hydrogels containing MgMOF74, CaMOF74, and Zn(Atz)(Py). The composite hydrogels are biodegradable, being completely degraded after 15 days by the action of collagenase and papain. The composites showed high biocompatibility reaching cell viabilities up to 165.3 ± 8.6% and 112.3 ± 12.8% for porcine fibroblasts and human monocytes, respectively. The composites did not show hemolytic character and they showed antibacterial activity against Escherichia coli reaching up to 84 ± 5% of inhibition compared with amoxicillin (20 ppm). Further, the immunological assays revealed that the composites produce a favorable cell signaling stimulating the secretion of the TGF-β and MCP-1 cytokines and maintaining the secretion of TNF-α in normal levels. Finally, the composites showed potential to be used as controlled drug delivery systems reaching a release efficiency of 30.5 ± 2.5% for ketorolac. Finally, results revealed that ColGG-Zn(Atz)(Py) was the best formulation evaluated.