Antibody-targeted and streptomycin-chitosan oligosaccharide-modified gold nanoshells for synergistic chemo-photothermal therapy of drug-resistant bacterial infection

Review of Metal-Polyphenol Self-Assembled Nanoparticles: Synthesis, Properties, and Biological Applications in Inflammatory Diseases

Polyphenols, which are compounds characterized by the presence of phenolic hydroxyl groups, are abundantly found in natural plants and exist in highly complex forms within living organisms. As some of the most prevalent compounds in nature, polyphenols possess significant medicinal value due to their unique structural features, particularly their therapeutic efficacy in antitumor, anti-inflammatory, and antibacterial applications. In the context of inflammation therapy, polyphenolic compounds can inhibit the excessive release of inflammatory mediators from inflammatory cells, thereby mitigating inflammation. Furthermore, these compounds exhibit strong antioxidant properties, enabling them to scavenge free radicals and reactive oxygen species (ROS), reduce oxidative stress-related damage, and exert anti-inflammatory effects. Due to their multiple phenolic hydroxyl groups and their ability to chelate various metals, polyphenols are extensively utilized in the synthesis of self-assembled nanoparticles for the treatment of various diseases. Numerous studies have demonstrated that the therapeutic profile of nanoparticles formed through self-assembly with metal ions surpasses that of polyphenolic compounds alone. This Review will focus on the self-assembly of different polyphenolic compounds with various metal ions to generate nanoparticles, their characterization, and their therapeutic applications in inflammation-related diseases, providing researchers with new insights into the synthetic study of metal-polyphenol nanocomposites and their biological applications.

Janus-Structured Micro/Nanomotors: Self-Propelled Mechanisms and Biomedical Applications

Self-propelled micro/nanomotors (MNMs), which can convert other energy into mechanical motion, have attracted considerable attention due to their potential applications in diverse fields. Due to the asymmetric structures and 2 or more chemically discrepant composites constructed in the Janus nanoparticles, asymmetrical forces can be created in the physical environment. Thus, MNMs with Janus structures have been widely studied for revealing possible driving mechanisms. This tutorial review covers the most representative examples of Janus-structured MNMs developed so far, which are self-propelled by different mechanisms. We focus on Janus MNMs that exhibit self-propelled motion in liquid environments and their potential applications in biomedicine, including drug delivery, cancer therapy, bioimaging, and biosensing. The driving mechanisms and challenges associated with constructing asymmetric fields are deeply discussed, along with future opportunities for these versatile and promising MNMs. This review provides an overview of the rapidly evolving field of MNMs and their potential applications, serving as a valuable resource for researchers and others interested in this field.

Aggregation-induced emission-based phototheranostics to combat bacterial infection at wound sites: A review

The healing of chronic wounds infected by bacteria has attracted increasing global concerns. In the past decades, antibiotics have certainly brought hope to cure bacteria-infected chronic wounds. However, the misuse of antibiotics leads to the emergence of numerous multidrug-resistant bacteria, which aggravate the health threat to clinical patients. To address these increasing challenges, scientists are committed to creating novel non-antibiotic strategies to kill bacteria and promote bacteria-infected chronic wound healing. Fortunately, with the quick development of nanotechnology, the representatives of phototherapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), exhibit promising possibilities in promoting bacteria-infected wound healing. Well-known, photothermal agents and photosensitizers largely determine the effects of PTT and PDT. A common problem for these molecules is the aggregation-induced quenching effect, which highly limits their further applicability in biomedical and clinical fields. Fortunately, the occurrence of aggregation-induced emission luminogens (AIEgens) efficiently overcomes the photobleaching and exhibit advantages, such as strongly aggregated emission, superior photostability, aggregation-enhanced reactive oxygen species (ROS), and heat generation, which makes great sense to the development of PTT and PDT. This article reviews various studies conducted on novel AIEgen-based materials that can mediate potent PDT, PTT, and a combination of PDT and PTT to promote bacteria-infected chronic wound healing.

Advances in the preparation, characterization, and biological functions of chitosan oligosaccharide derivatives: A review

Chitosan oligosaccharide (COS), which represent the positively charged basic amino oligosaccharide in nature, is the deacetylated and degraded products of chitin. COS has become the focus of intensive scientific investigation, with a growing body of practical and clinical studies highlighting its remarkable health-enhancing benefits. These effects encompass a wide range of properties, including antibacterial, antioxidant, anti-inflammatory, and anti-tumor activities. With the rapid advancements in chemical modification technology for oligosaccharides, many COS derivatives have been synthesized and investigated. These newly developed derivatives possess more stable chemical structures, improved biological activities, and find applications across a broader spectrum of fields. Given the recent interest in the chemical modification of COS, this comprehensive review seeks to consolidate knowledge regarding the preparation methods for COS derivatives, alongside discussions on their structural characterization. Additionally, various biological activities of COS derivatives have been discussed in detail. Lastly, the potential applications of COS derivatives in biomedicine have been reviewed and presented.

Nanotechnology-driven strategies to enhance the treatment of drug-resistant bacterial infections

The misuse of antibiotics has led to increased bacterial resistance, posing a global public health crisis and seriously endangering lives. Currently, antibiotic therapy remains the most common approach for treating bacterial infections, but its effectiveness against multidrug-resistant bacteria is diminishing due to the slow development of new antibiotics and the increase of bacterial drug resistance. Consequently, developing new a\ntimicrobial strategies and improving antibiotic efficacy to combat bacterial infection has become an urgent priority. The emergence of nanotechnology has revolutionized the traditional antibiotic treatment, presenting new opportunities for refractory bacterial infection. Here we comprehensively review the research progress in nanotechnology-based antimicrobial drug delivery and highlight diverse platforms designed to target different bacterial resistance mechanisms. We also outline the use of nanotechnology in combining antibiotic therapy with other therapeutic modalities to enhance the therapeutic effectiveness of drug-resistant bacterial infections. These innovative therapeutic strategies have the potential to enhance bacterial susceptibility and overcome bacterial resistance. Finally, the challenges and prospects for the application of nanomaterial-based antimicrobial strategies in combating bacterial resistance are discussed. This article is categorized under: Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

Redirecting Antigens by Engineered Photosynthetic Bacteria and Derived Outer Membrane Vesicles for Enhanced Cancer Immunotherapy

Significant strides have been made in the development of cancer vaccines to combat malignant tumors. However, the natural immunosuppressive environment within tumors, known as the tumor microenvironment (TME), hampers the uptake and presentation of antigens by antigen-presenting cells (APCs) within the tumor itself. This limitation results in inadequate activation of immune responses against cancer. In contrast, immune cells in peritumoral tissue maintain their normal functions. In this context, we present an interesting approach to enhance cancer immunotherapy by utilizing engineered photosynthetic bacteria (PSB) and their outer membrane vesicles (OMVPSB) to capture and transport antigens to the outer regions of the tumor. We modified PSB with maleimide (PSB-MAL), which, when exposed to near-infrared (NIR) laser-mediated photothermal therapy (PTT), induced extensive cancer cell death and the release of tumor antigens. Subsequently, the NIR-phototactic PSB-MAL transported these tumor antigens to the peripheral regions of the tumor under NIR laser exposure. Even more intriguingly, PSB-MAL-derived OMVPSB-MAL effectively captured and delivered antigens to tumor-draining lymph nodes (TDLNs). This facilitated enhanced antigen presentation by mature and fully functional APCs in the TDLNs. This intricate communication network between PSB-MAL, the OMVPSB-MAL, and APCs promoted the efficient presentation of tumor antigens in the tumor periphery and TDLNs. Consequently, there was a notable increase in the infiltration of cytotoxic T lymphocytes (CTLs) into the tumor, triggering potent antitumor immune responses in both melanoma and breast cancer models. This cascade of events resulted in enhanced suppression of tumor metastasis and recurrence, underscoring the robust efficacy of our approach. Our interesting study, harnessing the potential of bacteria and OMVs to redirect tumor antigens for enhanced cancer immunotherapy, provides a promising path toward the development of personalized cancer vaccination strategies.

Multifunctional chondroitin sulfate based hydrogels for promoting infected diabetic wounds healing by chemo-photothermal antibacterial and cytokine modulation

Diabetic foot (DF) is difficult to heal due to the formation of drug-resistant bacterial biofilms and dysregulation of the wound microenvironment. To solve this problem, multifunctional hydrogels were prepared by in situ or spraying with 3-aminophenylboronic acid modified oxidized chondroitin sulfate (APBA-g-OCS), polyvinyl alcohol (PVA) and black phosphorus/bismuth oxide/ε-polylysine (BP/Bi₂O₃/ε-PL) as precursors for promoting infected diabetic wounds healing. The hydrogels display multiple stimulus responsiveness, strong adhesion and rapid self-healing ability owing to the dynamic borate ester bonds, hydrogen bonds and π-π conjugation cross-link points, remain synergistic chemo-photothermal antibacterial effect and anti-biofilm formation ability due to the doping of BP/ Bi₂O₃/ε-PL into the hydrogel by dynamic imine bonds crosslinking and possess anti-oxidation and inflammatory chemokine adsorption ability attributing to the presence of APBA-g-OCS. Most importantly, as a result of the above functions, the hydrogels can not only respond to the wound microenvironment to conduct combined PTT and chemotherapy for efficient anti-inflammation, but also improve the wound microenvironment by scavenging ROS and regulating the expression of cytokines, thus further accelerating collagen deposition, promoting granulation tissue formation and angiogenesis, finally promoting the healing of infected wounds in diabetic rats.