A photo-thermal nanocomposite capable of relieving inflammatory response to compete multidrug-resistant pseudomonas aeruginosa infection

Magnetothermal and ultrasound-activated nanoplatform for the inhalable therapy of bacterial lung infections

Antibiotic resistance in Klebsiella pneumoniae infections presents significant challenges in treating lung inflammation. To overcome tissue penetration barriers and modulate inflammatory responses, innovative therapeutic approaches are essential. This study introduces an inhalable nanoplatform, FexSy:Gd@PVP (FGP), based on polyvinylpyrrolidone-modified gadolinium-doped nonstoichiometric iron sulfide nanostructures. The platform integrates synergistic magnetic-ultrasound activation with magnetothermal therapy (mMHT), sonodynamic therapy (SDT), and gas therapy (GT) for targeted bacterial lung infection treatment. Gadolinium incorporation enhances the magnetothermal activation, improving magnetothermal conversion efficiency and sonodynamic performance by increasing magnetic anisotropy, narrowing the semiconductor bandgap, and enriching sulfur vacancies. Delivered via nebulized inhalation, FGP reaches infected lung tissues noninvasively. Exposure to alternating magnetic fields (AMF) and ultrasound (US) generates localized heat and reactive oxygen species (ROS), effectively eliminating bacteria. Simultaneously, AMF and US trigger hydrogen sulfide (H2S) release in the acidic microenvironment, reducing inflammation by inhibiting inflammatory factors such as TNF-α and IL-1β through suppression of STAT3 and ERK phosphorylation. This magnetic-ultrasound co-activated inhalable nanoplatform offers a powerful multimodal therapeutic strategy for overcoming clinical challenges associated with bacterial lung infections. STATEMENT OF SIGNIFICANCE: This study introduces an inhalable nanoplatform that effectively treats multidrug-resistant Klebsiella pneumoniae lung infections. By integrating magnetothermal, sonodynamic, and gas therapies, this system eradicates bacteria and reduces inflammation. It uses gadolinium-doped iron sulfide nanostructures to enhance heat, reactive oxygen species, and hydrogen sulfide production, targeting deep lung infections precisely. Unlike traditional antibiotics, this noninvasive approach has minimal side effects and addresses both bacterial clearance and inflammation. This innovative strategy offers a promising solution for antibiotic-resistant infections and could revolutionize respiratory disease management.

Multifunctional Photothermal Nanorods for Targeted Treatment of Drug-Resistant Bacteria-Induced Wound Healing

The challenge of drug-resistant bacteria-induced wound healing in clinical and public healthcare settings is significant due to the negative impacts on surrounding tissues and difficulties in monitoring the healing progress. We developed photothermal antibacterial nanorods (AuNRs-PU) with the aim of selectively targeting and combating drug-resistant Pseudomonas aeruginosa (P. aeruginosa). The AuNRs-PU were engineered with a bacterial-specific targeting polypeptide (UBI29-41) and a bacterial adhesive carbohydrate polymer composed of galactose and phenylboronic acid. The objective was to facilitate sutureless wound closure by specially distinguishing between bacteria and nontarget cells and subsequently employing photothermal methods to eradicate the bacteria. AuNRs-PU demonstrated high photothermal conversion efficiency in 808 nm laser and effectively caused physical harm to drug-resistant P. aeruginosa. By integrating the multifunctional bacterial targeting copolymer onto AuNRs, AuNRs-PU showed rapid and efficient bacterial targeting and aggregation in the presence of bacteria and cells, consequently shielding cells from bacterial harm. In a diabetic rat wound model, AuNRs-PU played a crucial role in enhancing healing by markedly decreasing inflammation and expediting epidermis formation, collagen deposition, and neovascularization levels. Consequently, the multifunctional photothermal therapy shows promise in addressing the complexities associated with managing drug-resistant infected wound healing.

Photoresponsive Multirole Nanoweapon Camouflaged by Hybrid Cell Membrane Vesicles for Efficient Antibacterial Therapy of Pseudomonas aeruginosa-Infected Pneumonia and Wound

Exploring effective antibacterial approaches for targeted treatment of pathogenic bacterial infections with reduced drug resistance is of great significance. Combinational treatment modality that leverages different therapeutic components can improve the overall effectiveness and minimize adverse effects, thus displaying considerable potential against bacterial infections. Herein, red blood cell membrane fuses with macrophage membrane to develop hybrid cell membrane shell, which further camouflages around drug-loaded liposome to fabricate biomimetic liposome (AB@LRM) for precise antibacterial therapy. Specifically, photoactive agent black phosphorus quantum dots (BPQDs) and classical antibiotics amikacin (AM) are loaded in AB@LRM to accurately target the inflammatory sites through the guidance of macrophage membrane and long residence capability of red blood cell membrane, eventually exerting efficacious antibacterial activities. Besides, due to the excellent photothermal and photodynamic properties, BPQDs act as an efficient antibacterial agent when exposed to near-infrared laser irradiation, dramatically increasing the sensitivity of bacteria to antibiotics. Consequently, the synergistic sterilizing effect produced by AB@LRM further restricts bacterial resistance. Upon laser irradiation, AB@LRM shows superior anti-inflammatory and antibacterial properties in models of P. aeruginosa-infected pneumonia and wounds. Hence, this light-activatable antibacterial nanoplatform with good biocompatibility presents great potential to advance the clinical development in the treatment of bacterial infections.

Nanocomposites against Pseudomonas aeruginosa biofilms: Recent advances, challenges, and future prospects

Pseudomonas aeruginosa is an opportunistic bacterial pathogen that causes life-threatening and persistent infections in immunocompromised patients. It is the culprit behind a variety of hospital-acquired infections owing to its multiple tolerance mechanisms against antibiotics and disinfectants. Biofilms are sessile microbial aggregates that are formed as a result of the cooperation and competition between microbial cells encased in a self-produced matrix comprised of extracellular polymeric constituents that trigger surface adhesion and microbial aggregation. Bacteria in biofilms exhibit unique features that are quite different from planktonic bacteria, such as high resistance to antibacterial agents and host immunity. Biofilms of P. aeruginosa are difficult to eradicate due to intrinsic, acquired, and adaptive resistance mechanisms. Consequently, innovative approaches to combat biofilms are the focus of the current research. Nanocomposites, composed of two or more different types of nanoparticles, have diverse therapeutic applications owing to their unique physicochemical properties. They are emerging multifunctional nanoformulations that combine the desired features of the different elements to obtain the highest functionality. This review assesses the recent advances of nanocomposites, including metal-, metal oxide-, polymer-, carbon-, hydrogel/cryogel-, and metal organic framework-based nanocomposites for the eradication of P. aeruginosa biofilms. The characteristics and virulence mechanisms of P. aeruginosa biofilms, as well as their devastating impact and economic burden are discussed. Future research addressing the potential use of nanocomposites as innovative anti-biofilm agents is emphasized. Utilization of nanocomposites safely and effectively should be further strengthened to confirm the safety aspects of their application.

Synthesis and molecular docking study of α-aminophosphonates as potential multi-targeting antibacterial agents

Antibacterial compounds that reduce extracellular polymeric substances (EPS) are needed to avoid bacterial biofilms in water pipelines. Herein, green one-pot synthesis of α-aminophosphonates (α-Amps) [A-G] was achieved by using ionic liquid (IL) as a Lewis acid catalyst. The synthesized α-Amp analogues were tested against different bacteria such as Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. The representative [B] analogue showed an efficient antibacterial effect with MIC values of 3.13 μg/mL for E. coli, P. aeruginosa, and 6.25 μg/mL for B. subtilis. Additionally, a strong ability to eliminate the mature bacterial biofilm, with super-MIC values of 12.5 μg/mL for E. coli, P. aeruginosa, and 25 μg/mL for B. subtilis. Moreover, bacterial cell disruption by ROS formation was also tested, and the compound [B] revealed the highest ROS level compared to other compounds and the control, and efficiently destroyed the extracellular polymeric substances (EPS). The docking study confirmed strong interactions between [B] analogue and protein structures with a binding affinity of -6.65 kCal/mol for the lyase protein of gram-positive bacteria and -6.46 kCal/mol for DNA gyrase of gram-negative bacteria. The results showed that α-Amps moiety is a promising candidate for developing novel antibacterial and anti-biofilm agents for clean water supply.

Nanozyme-based inulin@nanogold for adhesive and antibacterial agent with enhanced biosafety

Nanozymes with oxidase or peroxidase-mimicking activity have emerged as a promising alternative for disinfecting resistant pathogens. However, further research and clinical applications of nanozymes are hampered by their low in vivo biosafety and biocompatibility. In this study, inulin-confined gold nanoparticles (IN@AuNP) are synthesized as an antibacterial agent via a straightforward in situ reduction of Au3+ ions by the hydroxyl groups in inulin. The IN@AuNP exhibits both peroxidase-mimicking and oxidase-mimicking catalytic activities, of which the maximum reaction velocity (Vmax) for H2O2 is 2.66 times higher than that of horseradish peroxidase. IN@AuNP can catalyze the production of reactive oxygen species (ROS), resulting in effective antibacterial behavior against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. Abundant hydroxyl groups retained in inulin endow the nanozyme with high adhesion to bacteria, reducing the distance between the captured bacteria and ROS, achieving an antibacterial ratio of 100 % within 1 h. Importantly, due to the natural biosafety and non-absorption of the dietary fiber inulin, as well as the inability of inulin-trapped AuNP to diffuse, the IN@AuNP exhibits high biosafety and biocompatibility under physiological conditions. This work is expected to open a new avenue for nanozymes with great clinical application value.

Advances in reparative materials for infectious bone defects and their applications in maxillofacial regions

Infectious bone defects are characterized by the partial loss or destruction of bone tissue resulting from bacterial contaminations subsequent to diseases or external injuries. Traditional bone transplantation and clinical methods are insufficient in meeting the treatment demands for such diseases. As a result, researchers have increasingly focused on the development of more sophisticated biomaterials for improved therapeutic outcomes in recent years. This review endeavors to investigate specific reparative materials utilized for the treatment of infectious bone defects, particularly those present in the maxillofacial region, with a focus on biomaterials capable of releasing therapeutic substances, functional contact biomaterials, and novel physical therapy materials. These biomaterials operate via heightened antibacterial or osteogenic properties in order to eliminate bacteria and/or stimulate bone cells regeneration in the defect, ultimately fostering the reconstitution of maxillofacial bone tissue. Based upon some successful applications of new concept materials in bone repair of other parts, we also explore their future prospects and potential uses in maxillofacial bone repair later in this review. We highlight that the exploration of advanced biomaterials holds promise in establishing a solid foundation for the development of more biocompatible, effective, and personalized treatments for reconstructing infectious maxillofacial defects.

Nanomaterials for Delivering Antibiotics in the Therapy of Pneumonia

Bacterial pneumonia is one of the leading causes of death worldwide and exerts a significant burden on health-care resources. Antibiotics have long been used as first-line drugs for the treatment of bacterial pneumonia. However, antibiotic therapy and traditional antibiotic delivery are associated with important challenges, including drug resistance, low bioavailability, and adverse side effects; the existence of physiological barriers further hampers treatment. Fortunately, these limitations may be overcome by the application of nanotechnology, which can facilitate drug delivery while improving drug stability and bioavailability. This review summarizes the challenges facing the treatment of bacterial pneumonia and also highlights the types of nanoparticles that can be used for antibiotic delivery. This review places a special focus on the state-of-the-art in nanomaterial-based approaches to the delivery of antibiotics for the treatment of pneumonia.