A glucose-powered antimicrobial system using organic-inorganic assembled network materials

Combatting Fungal Infections: Advances in Antifungal Polymeric Nanomaterials

Fungal pathogens cause over 6.5 million life-threatening systemic infections annually, with mortality rates ranging from 20 to 95%, even with medical intervention. The World Health Organization has recently emphasized the urgent need for new antifungal drugs. However, the range of effective antifungal agents remains limited and resistance is increasing. This Review explores the current landscape of fungal infections and antifungal drugs, focusing on synthetic polymeric nanomaterials like nanoparticles that enhance the physicochemical properties of existing drugs. Additionally, we examine intrinsically antifungal polymers that mimic naturally occurring peptides. Advances in polymer characterization and synthesis now allow precise design and screening for antifungal activity, biocompatibility, and drug interactions. These antifungal polymers represent a promising new class of drugs for combating fungal infections.

Beyond External Light: On-Spot Light Generation or Light Delivery for Highly Penetrated Photodynamic Therapy

External light sources, such as lasers, light emitting diodes (LEDs) and lamps, are widely applied in photodynamic therapy (PDT); however, their use is severely limited by the nature of shallow tissue penetration depth. The recent exploration of light delivery or local generation on tumor sites has attracted much attention, owing to the fact that these systems are significantly endowed with high tissue penetration. In this review, we briefly introduced the principle of "on-spot light generation or delivery systems" in PDT. These systems are divided into different categories: (1) implantable luminescence, (2) mechanoluminescence, (3) electrochemiluminescence, (4) Cerenkov luminescence, (5) chemiluminescence, and (6) bioluminescence. Finally, their applications, advantages, and disadvantages in PDT will be appropriately summarized and further discussed in detail. We believe that this review will provide general guidance for the further design of light generation or delivery systems and clinical studies for PDT-mediated cancer treatments with unparalleled merits.

Progress of polymer-based strategies in fungal disease management: Designed for different roles

Fungal diseases have posed a great challenge to global health, but have fewer solutions compared to bacterial and viral infections. Development and application of new treatment modalities for fungi are limited by their inherent essential properties as eukaryotes. The microorganism identification and drug sensitivity analyze are limited by their proliferation rates. Moreover, there are currently no vaccines for prevention. Polymer science and related interdisciplinary technologies have revolutionized the field of fungal disease management. To date, numerous advanced polymer-based systems have been developed for management of fungal diseases, including prevention, diagnosis, treatment and monitoring. In this review, we provide an overview of current needs and advances in polymer-based strategies against fungal diseases. We high light various treatment modalities. Delivery systems of antifungal drugs, systems based on polymers' innate antifungal activities, and photodynamic therapies each follow their own mechanisms and unique design clues. We also discuss various prevention strategies including immunization and antifungal medical devices, and further describe point-of-care testing platforms as futuristic diagnostic and monitoring tools. The broad application of polymer-based strategies for both public and personal health management is prospected and integrated systems have become a promising direction. However, there is a gap between experimental studies and clinical translation. In future, well-designed in vivo trials should be conducted to reveal the underlying mechanisms and explore the efficacy as well as biosafety of polymer-based products.

Photodynamic Antimicrobial Therapy Based on Conjugated Polymers

Pathogenic microorganisms have been a serious threat to human life and have become a public health problem of global concern. However, in the actual treatment there is a lack of efficient antimicrobial strategies which do not easily develop drug resistance; this can lead to inaccurate drug treatment that worsens the infection and even threatens life. With the emergence of a variety of drug-resistant bacteria and fungi, photodynamic therapy has gradually become one of the most promising treatment methods for drug-resistant bacteria infection; this is because it is controllable, non-invasive, and not prone to cause the development of drug resistance. Organic conjugated polymers that possess high fluorescence intensity, a large molar extinction coefficient, excellent light stability, an adjustable energy band, easy modification, good biocompatibility, and the ability to photosensitize oxygen to produce reactive oxygen species have been widely used in the fields of solar cells, highly sensitive detection systems, biological imaging, and anti-cancer and anti-microbial treatment. Photodynamic therapy is non-invasive and has high temporal and spatial resolution and is a highly effective antimicrobial treatment that does not easily induce drug resistance; it has also stimulated the scientific research enthusiasm of researchers and has become a research hotspot in the antimicrobial field. In this review, the photodynamic antibacterial applications of conjugated polymers with different structure types are summarized, and their development directions are considered.

Organic photosensitizers for antimicrobial phototherapy

Microbial infectious diseases, especially those caused by new and antibiotic-resistant pathogenic microbes, have become a significant threat to global human health. As an antibiotic-free therapy, phototherapy is a promising approach to treat microbial infections due to its spatiotemporal selectivity, non-invasiveness, minimal side effects, and broad antimicrobial spectrum. Although organic photosensitizer-based antimicrobial phototherapy has been extensively studied over the last decade, there has been no specific review article on this topic yet. It is important and timely to summarize recent research progress in this field. This tutorial review highlights the concept and significance of phototherapy and summarizes innovative types of organic photosensitizers with design strategies to deal with microbial infections. In addition, examples of organic antimicrobial photosensitizers, including antibacterial photosensitizers, antiviral photosensitizers, and antifungal photosensitizers are discussed. Finally, current challenges and future directions of organic photosensitizer-based phototherapy for clinical antimicrobial applications are presented. We believe that this tutorial review will provide general guidance for the future development of efficient photosensitizers and encourage preclinical and clinical studies for phototherapy-mediated antimicrobial treatments.

Glucose Oxidase, an Enzyme "Ferrari": Its Structure, Function, Production and Properties in the Light of Various Industrial and Biotechnological Applications

Glucose oxidase (GOx) is an important oxidoreductase enzyme with many important roles in biological processes. It is considered an "ideal enzyme" and is often called an oxidase "Ferrari" because of its fast mechanism of action, high stability and specificity. Glucose oxidase catalyzes the oxidation of β-d-glucose to d-glucono-δ-lactone and hydrogen peroxide in the presence of molecular oxygen. d-glucono-δ-lactone is sequentially hydrolyzed by lactonase to d-gluconic acid, and the resulting hydrogen peroxide is hydrolyzed by catalase to oxygen and water. GOx is presently known to be produced only by fungi and insects. The current main industrial producers of glucose oxidase are Aspergillus and Penicillium. An important property of GOx is its antimicrobial effect against various pathogens and its use in many industrial and medical areas. The aim of this review is to summarize the structure, function, production strains and biophysical and biochemical properties of GOx in light of its various industrial, biotechnological and medical applications.

AgNPs/nGOx/Apra Nanocomposites for Synergistic Antimicrobial Therapy and Scarless Skin Recovery

The misuse of antimicrobials has caused a remarkable increase of antibiotic-resistant bacteria. Developing novel antimicrobial agents with high activity and low rates of resistance development is in great demand yet...

Conjugated Polymers for Biomedical Applications

Conjugated polymers (CPs) are a series of organic semiconductor materials with large π-conjugated backbones and delocalized electronic structures. Due to their specific photophysical properties and photoelectric effects, plenty of CPs...

Infrequent metadynamics study of rare-event electrostatic channeling

The efficiency of cascade reactions, which consist of multiple chemical transformations that occur in a single pot without purification steps, is limited by the transport efficiency of intermediates between adjacent steps. Electrostatic channeling is a proven strategy for intermediate transfer in natural chemical cascades, but implementation into artificial cascades remains a challenge. Here, we combine infrequent metadynamics (InMetaD), umbrella sampling (US), and kinetic Monte Carlo (KMC) models to computationally study the transfer mechanism of glucose-6-phosphate (G6P) on a poly-arginine peptide bridging hexokinase (HK) and glucose-6-dehydrogenase (G6PDH). Transport of G6P by hopping in the presence of poly-arginine peptides is shown to be a rare event, and InMetaD is used to compute the hopping activation energy. US simulations capture the configurational change in the desorption process and enable the determination of the desorption energy. Parameterized by these results, a KMC model is used to estimate transport efficiency for the bridged enzyme complex. Results are compared to a similar complex using a poly-lysine bridge, using kinetic lag time as a metric. Even at a high ionic strength of 120 mM, poly-arginine peptides may be capable of more efficient transport as compared to poly-lysine, with a predicted lag time of 6 seconds for poly-arginine, compared to a previously reported lag time of 59 seconds for poly-lysine. This work indicates that poly-arginine peptides may be an improved bridge structure for electrostatic channeling of anionic intermediates.

Self-luminescent photodynamic therapy and pathogen detection for infectious diseases

The importance of detection and treatments of infectious diseases has been stressed to the world by the ongoing COVID-19 pandemic. As a substitution of an external light source, self-luminescent therapeutics featuring in situ light emission aims to address the lack of tissue penetration in conventional photodynamic therapy (PDT). Luminol-based self-luminescent systems are successfully incorporated in PDT and detection of pathogens in infectious diseases. In these systems, luminol/hydrogen peroxide is served as luminescence source which can be activated by horseradish peroxidase (HRP). As a supplement strategy to the HRP-based bioluminescence, electrochemiluminescence (ECL) provided an electric-driven therapeutic solution and demonstrated potential capabilities of wearable healthcare devices with properly constructed transparent flexible hydrogels. Besides the diagnosis of infection and detection of bacteria, fungi and virus in solution or powder samples have been achieved by ATP-derived self-luminescence as the light source. In this inspirational note, we provide an overview on latest progress in the PDT and microbial detection by self-luminescent systems with an emphasis on the bioluminescence and ECL.

Difunctionalized pillar[5]arene-based polymer nanosheets for photodynamic therapy of Staphylococcus aureus infection

Bacterial infections pose severe threats to global public health security. Developing antibacterial agents with both high efficiency and safety to handle this problem has become a top priority. Here, highly stable and effective polymer nanosheets have been constructed by the covalent co-assembly of a pillar[5]arene derivative and metalloporphyrin for photodynamic antibacterial therapy (PDAT). The monolayer nanosheets are strongly positively charged and thus capable of binding with Staphylococcus aureus (SA) through electrostatic interactions. Additionally, the nanosheets can be activated to generate reactive oxygen species (ROS) under white-light irradiation, and exhibit satisfactory antibacterial performance towards SA. More importantly, cell viability assays demonstrate that the nanosheets show little to no cytotoxicity impact on mammalian cells even when the concentrations are much higher than those employed in the antibacterial studies. The above results suggest that the polymer nanosheets could be an effective antibacterial agent to overcome bacterial infections and hold a broad range of potential applications in real life.

A high local DNA concentration for nucleating a DNA/Fe coordination shell on gold nanoparticles

Preparing DNA/Fe coordination nanoparticles in solution requires a high concentration of DNA. Herein we grew a DNA/Fe shell on DNA-functionalized gold nanoparticles. Taking advantage of the high local DNA density, the required DNA concentration decreased 60-fold, and the size can be controlled. This hybrid material allowed drug loading and colorimetric sensing.

Precisely Defined Conjugated Oligoelectrolytes for Biosensing and Therapeutics

Conjugated oligoelectrolytes (COEs) are a relatively new class of synthetic organic molecules with, as of yet, untapped potential for use in organic optoelectronic devices and bioelectronic systems. COEs also offer a novel molecular approach to biosensing, bioimaging, and disease therapy. Substantial progress has been made in the past decade at the intersection of chemistry, materials science, and the biological sciences developing COEs and their polymer analogues, namely, conjugated polyelectrolytes (CPEs), into synthetic systems with biological and biomedical utility. CPEs have traditionally attracted more attention in arenas of sensing, imaging, and therapy. However, the precisely defined molecular structures and interactions of COEs offer potential key advantages over CPEs, including higher reliability and fluorescence quantum efficiency, larger diversity of subcellular targeting strategies, and improved selectivity to biomolecules. Here, the unique-and sometimes overlooked-properties of COEs are discussed and the noticeable progress in their use for biological sensing, imaging, and therapy is reviewed.

Chemiluminescence-initiated and in situ-enhanced photoisomerization for tissue-depth-independent photo-controlled drug release

Tissue-penetration-depth-independent self-luminescence is highly expected to perform photoisomerization-related bioapplications in vivo to overcome the limitation of shallow tissue-penetration from external photoexcitation. However, it remains extremely challenging because of lacking a target-specific high-intensity self-luminescence to precisely and effectively drive the photoisomerization. Here, we first report a target-specific tissue-depth-independent photoisomerization in vivo by developing a target-specific initiated and in situ-enhanced chemiluminescence (one of self-luminescence) strategy that overcomes the limitation of lacking target-specific high-intensity self-luminescence. Considering that photoisomerization shows boundless glamour in drug-controlled release for disease-specific chemotherapy, we demonstrated applicability of our strategy to apply it in tumor-specific self-luminescence-controlled drug chemotherapy. Specifically, a chemiluminescence substrate and chemiluminescence fluorophore (antitumor drug, CPT) were co-encapsulated in host-guest carriers composed of cyclodextrin and the photoisomerization molecule azobenzene. Tumor-specific H2O2-induced chemiluminescence preliminarily isomerizes azobenzene, triggering the partial dissociation of host-guest carriers and CPT release. Particularly, the initially released CPT again functions as a chemiluminescence enhancer to achieve in situ enhanced chemiluminescence, assuring target-specific enhanced isomerization and CPT release. With high tumor-inhibition-rate (73%) and no obvious therapy-side-effect in vivo indicates the good efficiency and target-specificity of our chemiluminescence-driven photoisomerization. Although we only demonstrated one example of a photoisomerization-related bioapplication, namely photoisomerization-controlled drug chemotherapy, our work provides guidelines to design various target-specific tissue-depth-independent photoisomerization for bioapplications.

Synthesis of amphiphilic poly(fluorene) derivatives for selective imaging of Staphylococcus aureus

Three amphiphilic poly(fluorene-co-phenylene) derivatives with different side chains (PFP-1, PFP-2, PFP-3) were designed and synthesized for exploring their detection and imaging of pathogens. Upon incubation with six kinds of different pathogens, it was found the three polymers could selectively interact with Staphylococcus aureus (S. aureus). Their selective imaging towards S. aureus were thus realized. The selective imaging towards S. aureus was also confirmed even under the blend of microbes. PFP-3 shows stronger fluorescence imaging signal than PFP-1 and PFP-2. Zeta potential and isothermal titration microcalorimetry (ITC) tests demonstrated that both electrostatic interactions and hydrophobic interactions played important roles in the binding between PFPs and pathogens. Thus, amphiphilic PFP-3 exhibits great potential for specific imaging of S. aureus in a simple and rapid manner.

Synthesis of photothermal nanocomposites and their application to antibacterial assays

In this work, we report a novel gold nanorod (AuNR)-based nanocomposite that shows strong binding to bacterium and high antibacterial efficiency. The AuNRs were used as a photothermal material to transform near-infrared radiation (NIR) into heat. We selected poly (acrylic acid) to modify the surface of the AuNRs based on a simple self-assembly method. After conjugation of the bacterium-binding molecule vancomycin, the nanocomposites were capable of efficiently gathering on the cell walls of bacteria. The nanocomposites exhibited a high bacterial inhibition capability owing to NIR-induced heat generation in situ. Therefore, the prepared photothermal nanocomposites show great potential for use in antibacterial assays.

Nucleobases, nucleosides, and nucleotides: versatile biomolecules for generating functional nanomaterials

The incorporation of biomolecules into nanomaterials generates functional nanosystems with novel and advanced properties, presenting great potential for applications in various fields. Nucleobases, nucleosides and nucleotides, as building blocks of nucleic acids and biological coenzymes, constitute necessary components of the foundation of life. In recent years, as versatile biomolecules for the construction or regulation of functional nanomaterials, they have stimulated interest in researchers, due to their unique properties such as structural diversity, multiplex binding sites, self-assembly ability, stability, biocompatibility, and chirality. In this review, strategies for the synthesis of nanomaterials and the regulation of their morphologies and functions using nucleobases, nucleosides, and nucleotides as building blocks, templates or modulators are summarized alongside selected applications. The diverse applications range from sensing, bioimaging, and drug delivery to mimicking light-harvesting antenna, the construction of logic gates, and beyond. Furthermore, some perspectives and challenges in this emerging field are proposed. This review is directed toward the broader scientific community interested in biomolecule-based functional nanomaterials.

Improvement Strategies, Cost Effective Production, and Potential Applications of Fungal Glucose Oxidase (GOD): Current Updates

Fungal glucose oxidase (GOD) is widely employed in the different sectors of food industries for use in baking products, dry egg powder, beverages, and gluconic acid production. GOD also has several other novel applications in chemical, pharmaceutical, textile, and other biotechnological industries. The electrochemical suitability of GOD catalyzed reactions has enabled its successful use in bioelectronic devices, particularly biofuel cells, and biosensors. Other crucial aspects of GOD such as improved feeding efficiency in response to GOD supplemental diet, roles in antimicrobial activities, and enhancing pathogen defense response, thereby providing induced resistance in plants have also been reported. Moreover, the medical science, another emerging branch where GOD was recently reported to induce several apoptosis characteristics as well as cellular senescence by downregulating Klotho gene expression. These widespread applications of GOD have led to increased demand for more extensive research to improve its production, characterization, and enhanced stability to enable long term usages. Currently, GOD is mainly produced and purified from Aspergillus niger and Penicillium species, but the yield is relatively low and the purification process is troublesome. It is practical to build an excellent GOD-producing strain. Therefore, the present review describes innovative methods of enhancing fungal GOD production by using genetic and non-genetic approaches in-depth along with purification techniques. The review also highlights current research progress in the cost effective production of GOD, including key advances, potential applications and limitations. Therefore, there is an extensive need to commercialize these processes by developing and optimizing novel strategies for cost effective GOD production.

Supramolecular Porphyrin Photosensitizers: Controllable Disguise and Photoinduced Activation of Antibacterial Behavior

A series of supramolecular photosensitizers were fabricated from porphyrin derivatives (Por) containing quaternary ammonium groups with cucurbit[7]uril (CB[7]) based on host-guest interactions. The antibacterial activity of Por in the dark could be turned off upon binding with CB[7], whereas the antibacterial activity under white-light illumination could be turned on. In addition, its antibacterial efficiency could be greatly enhanced by introducing metal ions. When Pd(II) was introduced into porphyrin, its antibacterial efficiency was enhanced from 40 to 100%. It should be noted that these small molecules showed little to no cytotoxicity toward mammalian cells even at concentrations higher than those under the antibacterial condition studied. This line of research will provide a strategy for germicides consisting of quaternary ammonium groups to fight against bacterial accumulation in the long term and holds huge potential for application in the real world.

Luciferase-Rose Bengal conjugates for singlet oxygen generation by bioluminescence resonance energy transfer

Conjugates of Rose Bengal and Renilla luciferase generated singlet oxygen upon binding with coelenterazine via bioluminescence resonance energy transfer (BRET). Since the applications of conventional PDT have been limited to superficial lesions due to the limited light penetration in tissue, BRET activated PDT which does not require external light illumination may overcome the limitations of conventional PDT.

Artificial tongue based on metal-biomolecule coordination polymer nanoparticles

We construct an array-based recognition system (the so-called artificial tongue) through the self-assembly of nucleotides, dyes and lanthanide ions. Metal ions are selected as model analytes for verifying its discrimination ability. The work provides valuable insights into the application and development of biomolecule-based materials.

Thermo-Controlled in Situ Phase Transition of Polymer-Peptides on Cell Surfaces for High-Performance Proliferative Inhibition

We herein report a thermocontrolled strategy for realizing in situ conformational transition of polymer-peptide conjugates at cell surfaces to manipulate and monitor HER2 receptor clustering, which finally result in effective breast cancer cell proliferation inhibition. Functional paring motifs (HBP) are covalently linked to a synthetic thermoresponsive polymer PNIPAAm to incorporate temperature control properties to HER2 targeting peptide. At 40 °C, the PNIPAAm polymers collapse and act as a "shield" to block the aggregation of HBP. Upon cooling to 35 °C, polymers are in their extended state and HBP are expose in aqueous and aggregate subsequently with enhanced fluorescence, allowing for promoting and in situ monitoring of receptor clustering. Ultimately, HER2 receptor clustering leads to cytoplasmic domain phosphorylation, which further results in effective cancer cell proliferation inhibition. We envision that this useful approach has the potential to be applied for molecule-targeted tumor therapy.

Bioluminescence-activated deep-tissue photodynamic therapy of cancer

Optical energy can trigger a variety of photochemical processes useful for therapies. Owing to the shallow penetration of light in tissues, however, the clinical applications of light-activated therapies have been limited. Bioluminescence resonant energy transfer (BRET) may provide a new way of inducing photochemical activation. Here, we show that efficient bioluminescence energy-induced photodynamic therapy (PDT) of macroscopic tumors and metastases in deep tissue. For monolayer cell culture in vitro incubated with Chlorin e6, BRET energy of about 1 nJ per cell generated as strong cytotoxicity as red laser light irradiation at 2.2 mW/cm² for 180 s. Regional delivery of bioluminescence agents via draining lymphatic vessels killed tumor cells spread to the sentinel and secondary lymph nodes, reduced distant metastases in the lung and improved animal survival. Our results show the promising potential of novel bioluminescence-activated PDT.