查找使用阿拉丁产品的科研文献

A Bacteria-Targeting Supramolecular Nanophotosensitizer for Combating Multidrug Resistant Bacteria

Wenlong Huang,Anan Wang,Wenchen Wang,Lihong Lin,Jianyu Rong,Jia Tian,Weian Zhang

The increasing prevalence of multidrug-resistant bacteria is a significant global health threat. In contrast to conventional antibiotic treatments, photodynamic therapy (PDT) offers a promising alternative by reducing the bacterial adaptability to antibiotics and bactericides. However, traditional photosensitizers encounter poor antimicrobial efficacy due to poor hydrophilicity of photosensitizers, short lifespan, narrow diffusion radius of reactive oxygen species (ROS), and the risk of exacerbating inflammation. In this study, we report a bacterial-targeting supramolecular nanophotosensitizer for combating multidrug resistant bacteria. The nanophotosensitizer, formed through host–guest interactions and self-assembly of tetra-cyclodextrin-modified silver porphyrin (AgTPP-CD4), adamantyl-modified phenylboronic acid (Ad-PBA), and curcumin (Cur), can effectively target and kill methicillin-resistant Staphylococcus aureus (MRSA). Moreover, it reduces inflammation and promotes wound healing in MRSA-infected wounds without inducing drug resistance. The combination of supramolecular chemistry and targeted PDT offers a promising strategy for combating multidrug-resistant bacterial infections.

Low molecular weight chitosan-coated silver nanoparticles are effective for the treatment of MRSA-infected wounds

Yinbo Peng,Chenlu Song,Chuanfeng Yang,Qige Guo,Min Yao

Design, synthesis, and optimization of Honokiol-Piperazine derivatives as lung-enriched agents against MRSA pneumonia infection

Ruixue Zhang,Yifan Zhong,Hongzhi Gong,Xinyue Deng,Haibo Peng,Yun He

Methicillin-resistant Staphylococcus aureus ( MRSA ) causes severe bacterial pneumonia; current therapies (e.g., vancomycin) suffer from poor pulmonary bioavailability and dose-limiting safety concerns, demanding precision lung-enriched agents. However, small-molecule lung-enriched antibacterials are relatively rare. Honokiol (HNK), a natural phenolic compound with broad pharmacological activities but moderate antibacterial potency and limited tissue selectivity, was selected as the scaffold. We integrated a piperazine moiety into HNK and synthesized a series of HNK–piperazine derivatives. Among them, 13   f showed potent activity primarily against Gram-positive bacteria, including MRSA (MIC: 2–4 μM; 16–32-fold more potent than HNK) together with preferential lung exposure. 13   f exhibited rapid bactericidal activity and showed minimal MIC shift under sub-MIC selection over 31 serial passages (MICₙ/MIC₀ = 1–2), whereas ciprofloxacin displayed a 256-fold increase over the same period; it also attenuated staphyloxanthin production and reduced biofilm biomass. Mechanistic assays suggested time- and concentration-dependent membrane-associated effects, as reflected by permeability/depolarization readouts, nucleic acid/protein leakage, SEM imaging, and complementary MD analyses, with more pronounced effects at higher exposures. Pharmacokinetic and biodistribution analyses revealed a 13-fold longer half-life and a 147.92-fold higher lung AUC for 13   f than for HNK. In a murine MRSA pneumonia model, 13   f substantially reduced pulmonary bacterial burden and showed in vivo activity in the same overall range as vancomycin under the tested dosing regimen. No obvious histopathological alterations were observed under the tested short-term conditions. Overall, this work demonstrated a small-molecule approach to combine lung enrichment with potent anti-MRSA activity, supporting the further preclinical evaluation of 13   f for MRSA pneumonia.

Macrophage-targeted dual-responsive hollow mesoporous silica nanosystem for photothermal and immunomodulatory elimination of intracellular MRSA

Qiao Guo,Yongchao Yao,Jipeng Xiao,Xinyu Lu,Yiyuan Pu,Ran Li,Zhuo Zhang,Penghai Tang,Yuchen Jiang,Jianbin Luo

Cascade-targeting mannose-HMSNs enable dual macrophage and intracellular MRSA targeting. • pH/NIR dual-responsive nanoparticles promote lysosomal escape and drug release. • Photothermal IR780 and curcumin synergistically eradicate intracellular MRSA in vivo. • Curcumin-modulated M1/M2 polarization attenuates inflammation and enhances antibacterial efficacy. Intracellular bacterial infections caused by methicillin-resistant Staphylococcus aureus (MRSA) pose serious threat to human health due to immune evasion and antibiotic resistance. Here, a new integrated drug delivery system (DDS) based on hollow mesoporous silica nanoparticles (HMSNs) with cascade-targeting, acidic/NIR dual responsive, photothermal antibacterial and immune modulation activities is reported. Mannose was grafted onto HMSNs through Schiff-base bond, resulting in Man-HMSNs. IR780 and curcumin (Cur) were coloaded into Man-HMSNs which resulted in the integrated drug delivery system, IR780/Cur@Man-HMSNs. The nanoparticles are specifically recognized and internalized by macrophages via mannose receptor recognition. Crucially, the acidic phagolysosome microenvironment triggers Schiff base cleavage to expose primary amine groups, achieving surface charge reversal from negative to positive that simultaneously promotes intracellular bacterial targeting through electrostatic adhesion and cargo release a cascade-targeting mechanism distinguishing this work from conventional HMSN platforms. Under NIR irradiation, photothermal and photodynamic effects directly eradicate intracellular MRSA while accelerating drug release. Cur enhances immune modulation by upregulating the M1/M2 polarization, which further promotes antibacterial capacity. In vitro, IR780/Cur@Man-HMSNs exhibits 92% MRSA biofilm eradication efficiency under acidic conditions. In vivo, it reduces the total bacterial burden to 2.45 log₁₀ CFU and achieves efficient intracellular MRSA elimination. IR780/Cur@Man-HMSNs show better intracellular bacteria elimination efficiency both in vitro and in vivo, compared with those of free IR780/Cur and individual IR780 or Cur loaded DDS. Therefore, the photothermal antibacterial and immune regulation integrated nanosystems with cascade targeting and acidic/NIR dual responsive properties provides a new method for treating intracellular bacterial infections. By mannose modification and co-loading of IR780 and curcumin, a multifunctional IR780/Cur@Man-HMSNs nanosystem was constructed for intracellular MRSA infection therapy. The nanosystem enables macrophage-mediated and intracellular bacteria cascade-targeting, undergoes surface charge reversal in acidic phagolysosomal microenvironments to promote bacterial interaction and lysosomal escape, and exhibits NIR-triggered drug release and photothermal antibacterial effects. Moreover, curcumin-mediated modulation of macrophage M1/M2 polarization alleviates inflammation and synergistically enhances antibacterial therapeutic efficacy. Download: Download high-res image (142KB) Download: Download full-size image

Bio-heterojunction-engineered recombinant collagen hydrogel orchestrates multimodal sterilization and immunomodulation for MRSA-infected wound healing

Chongyi Li,Zewen Chang,Yuxi Zhang,Shihong Shen,Lin Liu,Dan Zeng,Daidi Fan

Multidrug-resistant (MDR) bacterial infections, notably methicillin-resistant Staphylococcus aureus (MRSA), necessitate innovative antibiotic-free wound therapies. Here, a bio-heterojunction-integrated recombinant collagen hydrogel (CAP@MXene/CuTCPP) is designed that synergistically combines photothermal therapy (PTT), photodynamic therapy (PDT), and peroxidase-like (POD-like) activity for multimodal antibacterial action. The borate-bonded dynamically crosslinked hydrogel is composed of polyvinyl alcohol (PVA), 3-aminophenylboronic acid (APBA)-modified recombinant collagen (CF-1552), and MXene/CuTCPP bio-heterojunctions (bio-HJs). Under 808 nm near-infrared (NIR) irradiation, the MXene/CuTCPP bio-HJs exhibit a high photothermal conversion efficiency (44.51%), inducing localized hyperthermia to disrupt bacterial membranes. Importantly, the construction of a Schottky junction at the MXene/CuTCPP interface significantly accelerates photo-excited electron transfer, thereby catalytically amplifying the production of additional ROS ( 1 O 2 , ·O 2 − , ·OH) for synergistic bacterial eradication. This triple antibacterial mechanism ensures a 99.95% MRSA eradication rate without inducing drug resistance, while effectively removing the biofilm. In vivo, the hydrogel accelerates wound closure (98% by day 11) not only by providing a biomimetic scaffold but also by regulating the polarization of macrophages from M1 to M2, and significantly promoting angiogenesis. This work presents a biocompatible and self-adaptable platform that overcomes the killing-healing trade-off through synergistic energy/charge transfer integration, offering insights for advanced immunomodulatory wound management. A bio-heterojunction-integrated recombinant collagen hydrogel (CAP@MXene/CuTCPP) is designed for synergistic photothermal, photodynamic, and POD-like antibacterial therapy against MDR infections like MRSA. Featuring dynamic borate crosslinking and high photothermal efficiency (44.51%), it achieves 99.95% bacterial eradication, biofilm removal, and accelerated wound healing (98% closure by day 11) via ROS generation, macrophage polarization, and angiogenesis promotion. This platform advances antibiotic-free wound management.

Inflammation-responsive liposomes co-delivering tobramycin and nitric oxide for overcoming mucus barriers against MRSA pneumonia

Jia-Qi Zhang,Yue Wang,Jun-Ge Ou,Jia-Wen Feng,Ping Gui,Dong Ma,Guan-Hai Wang

An inhalable chitosan-coated liposomal system was developed for Tob/NO co-delivery. • LC@Tob/NO enhanced mucus penetration and enabled mildly acidic pH-responsive NO release. • Nebulized LC@Tob/NO disrupted MRSA biofilms and alleviated infected lung inflammation. Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia remains difficult to treat because mucus-associated transport barriers, biofilm formation, and excessive inflammation jointly limit therapeutic efficacy. Here, we developed a nebulizable chitosan-coated liposomal co-delivery system, LC@Tob/NO, for pulmonary treatment of MRSA pneumonia. The formulation integrates liposome-mediated pulmonary delivery, chitosan-associated surface reconstruction, tobramycin-mediated antibacterial activity, and mildly acidic inflammation-associated NO release from DETA/NO, thereby enabling localized Tob/NO co-loading for MRSA pneumonia therapy. LC@Tob/NO exhibited favorable physicochemical characteristics, enhanced transport through an artificial mucus matrix, and effective pulmonary deposition after nebulization. In vitro, the formulation showed potent antibacterial and antibiofilm activities against MRSA, while also attenuating oxidative stress and pro-inflammatory activation in macrophages. In a murine MRSA pneumonia model, nebulized LC@Tob/NO markedly reduced bacterial burden, alleviated lung edema and tissue injury, and suppressed inflammatory responses, with acceptable systemic biosafety. Supportive lung transcriptomic analysis suggested treatment-associated changes in immune and inflammatory pathways that were consistent with the observed bacterial clearance, cytokine reduction, and histological improvement. Collectively, LC@Tob/NO represents a promising inhalable biomaterial-based therapeutic strategy for MRSA pneumonia by integrating antibacterial activity with microenvironment regulation.

SDA-mediated high-sensitivity visual CRISPR/Cas12a detection platform for point-of-care detection of MRSA

Wenjia Dong,Xiaoyan Wu,Hongsheng Li,Junjie Yu,Siqi Xu,Yayun Jiang

Methicillin-resistant Staphylococcus aureus (MRSA) infections progress rapidly, posing a significant threat to patient health. Culture-based drug susceptibility testing and nucleic acid amplification methods are time-consuming and complex, requiring specialized instruments and technicians. To address these limitations, we present a novel, visual POCT platform for MRSA detection with the naked eye. This visualization method uses CRISPR/ Ca s12a to accurately identify target genes, cleave the strand displacement amplification ( SD A) template, and regulate the aggregation of DNA-functionalized gold nanoparticles ( Au NPs), with the resulting color change serving as a signal (CaSD@Au). The presence of the target gene activates CRISPR/Cas12a enzymatic activity, which cleaves the SDA template. This cleavage suppresses the SDA reaction, prevents DNA-AuNP aggregation, and maintains nanoparticle dispersion, resulting in a visible red color. In the absence of the target gene, the SDA reaction proceeds, and the gold nanoparticles aggregate, turning purple. Sensitivity analysis confirmed that CaSD@Au detects MRSA with a limit of detection of 5 cfu mL −1 . When combined with recombinase polymerase amplification (RPA), CaSD@Au showed detection performance comparable to qPCR in the actual detection of 20 clinical strains. Furthermore, this platform enables results to be determined simply by observing color changes with the naked eye, without the need for complex instruments. The CaSD@Au platform offers reliable, sensitive, and specific detection, enhancing the applicability of CRISPR/Cas12a-based assays for pathogen detection, especially in resource-limited settings.

Selective Capture, Separation, and Photothermal Inactivation of Methicillin-Resistant Staphylococcus aureus (MRSA) Using Functional Magnetic Nanoparticles

Chengnan Li,Zongshao Li,Yingying Gan,Fenglin Jiang,Huimin Zhao,Jeremy Tan,Yi Yan Yang,Peiyan Yuan,Xin Ding

Antibiotic-free antimicrobial strategies are urgently needed to address the rapid evolution of antimicrobial resistance and transmission of multidrug-resistance bacterial infections. Herein, we fabricated polydopamine-coated porous magnetic nanoparticles (pMNPs@PDA) for effective separation and photothermal killing of methicillin-resistant Staphylococcus aureus (MRSA). Taking advantage of the excellent bacteria-affinitive property of polydopamine, the nanoparticles were anchored on the surface of bacteria, permitting rapid and efficient MRSA capture and separation with over 99% removal via the application of a magnetic field in 30 min. It was found, for the first time, that polydopamine-coated magnetic nanoparticles displayed a selective capture of Gram-positive bacteria when compared with Gram-negative bacteria. The selectivity was attributed to the preferable binding capability of pMNPs@PDA to peptidoglycan (PGN) of Gram-positive bacteria, compared to the lipopolysaccharide (LPS) of Gram-negative bacteria. With the magnetic separation and photothermal properties, pMNPs@PDA exhibited efficient killing of the captured MRSA under the irradiation of near-infrared (NIR) light. Cell cytotoxicity testing demonstrated good biocompatibility of the nanoparticles. These antibiotic-free nanoparticles capable of fast capture, separation, and inactivation of MRSA may be potentially used for water disinfection, blood purification, and treatment of bacterial infections.

Lysozyme-based nanozyme encapsulated in double-network hydrogel for monitoring and repair of MRSA infected wounds

Guannan Le,Yuqing Li,Ling Cai,Li Zhang,Wei Pei,Xinyi Zhu,Shangcheng Xu,Jiarong Zhang,Jin Chen

The presence of bacterial infection at the wound site poses a huge socioeconomic burden to public health as it adversely affects the tissue regeneration and thereby prolongs the wound healing process. To overcome the “black-box” status of healing process, the effective monitoring and treatment of infected wound is imperative in clinical practice, which has urged continuous exploration of wound dressings with integrated abilities of antibacterial effect, timely diagnosis and therapy. In this study, a dual-functional hydrogel of antimicrobial and the ability to monitor wound infections was prepared. In the gel, antibacterial protein of lysozyme was used for the sufficient loading of hemin molecules. The obtained lysozyme@Hemin nanopaticles (Ly@He NPs) was co-encapsulated with AgNO 3 in the double-network hydrogel composed of gelatin and polyvinyl alcohol, which endows the obtained hydrogel not only desirable mechanical characteristics but dual capabilities of bactericidal effect and bacterial infection monitoring around the wound site. In addition to the sustained bactericidal effects by the silver leveraging from the hydrogel, the generation of abundant reactive hydroxyl radicals induced by the nanozyme of Ly@He NPs contributed significantly to the improved antibacterial activity of hydrogel. Moreover, based on the peroxidase (POD)-like activity, the prepared hydrogel was capable of monitoring the wound infection status by the colorimetric detection of glutathione, a biomarker of bacterial infection. Finally, both in vivo and in vitro experimental results pointed to the satisfying efficacy of the hydrogel to eliminate and monitor bacterial infection. Therefore, the proposed system holds enormous potentials in the development of integrated nanoplatforms for the diagnosis and on-demand treatment of bacteria-infected wounds.

Colorimetric and fluorescent dual-identification of Methicillin-Resistant Staphylococcus aureus (MRSA) using programmable CRISPR/Cas12a system

Xianfeng Wang,Chengxiang Chu,Yuanyi Deng,Yi Ma,Mei Yang,Huibo Luo,Danqun Huo,Changjun Hou

Accurate identification of Staphylococcus aureus ( S. aureus ) is crucial for food safety and clinical diagnosis. Particularly, identifying drug-resistant strains guides effective treatment and prevention of infectious diseases. Herein, we presented a highly efficient programmable CRISPR/Cas12a system for identification of methicillin-resistant S. aureus (MRSA). Genus-specific gene (spec gene) and methicillin-resistant gene (mecA gene) of S. aureus were amplified by PCR. According to the sequences of spec gene and mecA gene, corresponding programmable crRNAs were designed and prepared to construct CRISPR/Cas12a system, which recognized and bound to the PCR products through complementary interactions to activate the trans -cleavage activity of Cas12a. This led to the indiscriminate digestion of surrounding FQ-reporter, releasing a distinct fluorescence signal for MRSA identification. In addition, we devised a pair of AuNPs-DNA probes for colorimetric recognition of S. aureus . Target-triggered trans -cleavage for linker probe led to an non-aggregation of AuNPs-DNA probes pair. This led to a noticeable appearance of red color, enabling naked-eye detection. Thus, MRSA identification was realized with remarkable sensitivity and exceptional selectivity. Successful identification of MRSA in clinical samples validated the practical applications of the proposed CRISPR/Cas12a assay, establishing it as a universal platform for diagnosing pathogenic microorganisms with versatility and compatibility.

Evaluating the Immune Response of a Nanoemulsion Adjuvant Vaccine Against Methicillin-Resistant Staphylococcus aureus (MRSA) Infection

Xiaoqiang Zeng,Hongwu Sun,Yan Ye,Xing Luo,Dingyi Cai,Yun Yang,Ting Chen,Cun Sun,Shaotong Zhang,Hao Zeng

Nanoemulsion adjuvant vaccines have attracted extensive attention because of their small particle size, high thermal stability, and ability to induce validly immune responses. However, establishing a series of comprehensive protocols to evaluate the immune response of a novel nanoemulsion adjuvant vaccine is vital. Therefore, this article features a rigorous procedure to determine the physicochemical characteristics of a vaccine (by transmission electron microscopy [TEM], atomic force microscopy [AFM], and dynamic light scattering [DLS]), the stability of the vaccine antigen and system (by a high-speed centrifuge test, a thermodynamic stability test, SDS-PAGE, and western blot), and the specific immune response (IgG1, IgG2a, and IgG2b). Using this approach, researchers can evaluate accurately the protective effect of a novel nanoemulsion adjuvant vaccine in a lethal MRSA252 mouse model. With these protocols, the most promising nanoemulsion vaccine adjuvant in terms of effective adjuvant potential can be identified. In addition, the methods can help optimize novel vaccines for future development.

Prussian blue nano-enzyme-assisted photodynamic therapy effectively eradicates MRSA infection in diabetic mouse skin wounds

Aidi Tong,Chunyi Tong,Jialong Fan,Jingyi Shen,Caiyun Yin,Zhou Wu,Jiansong Zhang,Bin Liu

Antibiotic therapy can induce the generation of severe bacterial resistance, further challenging the usability of currently available drugs and treatment options. Therefore, it is essential to develop new strategies to effectively eradicate drug-resistant bacteria. Herein, we have reported a combinational strategy for the eradication of drug-resistant bacteria by using chlorin e6 (Ce6) loaded Prussian blue nanoparticles (PB NPs). This nanocomplex showed strong catalase activity and photodynamic properties. In vitro experiments demonstrated that CPB–Ce6 NPs effectively kill MRSA by generating ROS under laser irradiation. Meanwhile, the nano-enzyme activity of CPB NPs can decompose H2O2 in the bacterial microenvironment to upregulate the O2 level, which in turn alleviates hypoxia in the microenvironment and improves the antibacterial effect of PDT. In vivo results demonstrated that CPB–Ce6 NPs with laser irradiation effectively cleared MRSA and promoted infected wound repair in a diabetic mouse model and normal mice through upregulating VEGF. Moreover, CPB–Ce6 NPs showed excellent biosafety profiles in vitro and in vivo. From our point of view, this PDT based on PB NPs with nano-enzyme activity may provide an effective treatment for infections associated with drug-resistant microbes and tissue repair.