RESUMO
In this study, graphene oxide/N-halamine nanocomposite was synthesized through Pickering miniemulsion polymerization, which was then coated on cotton surface. The modified cotton exhibited excellent superhydrophobicity, which could effectively prevent microbial infestation and reduce the probability of hydrolysis of active chlorine, with virtually no active chlorine released in water after 72 h. Deposition of reduced graphene oxide nanosheets endowed cotton with ultraviolet-blocking properties, attributing to enhanced UV adsorption and long UV paths. Moreover, encapsulation of polymeric N-halamine resulted in improved UV stability, thus extending the life of N-halamine-based agents. After 24 h of irradiation, 85 % of original biocidal component (active chlorine content) was retained, and approximately 97 % of initial chlorine could be regenerated. Modified cotton has been proven to be an effective oxidizing material against organic pollutants and a potential antimicrobial substance. Inoculated bacteria were completely killed after 1 and 10 min of contact time, respectively. An innovative and simple scheme for determination of active chlorine content was also devised, and real-time inspection of bactericidal activity could be achieved to assure antimicrobial sustainability. Moreover, this method could be utilized to evaluate hazard classification of microbial contamination in different locations, thus broadening the application scope of N-halamine-based cotton fabrics.
Assuntos
Aminas , Antibacterianos , Fibra de Algodão , Gossypium , Látex , Nanoestruturas , Polimerização , Aminas/química , Aminas/efeitos da radiação , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/efeitos da radiação , Biofilmes/efeitos dos fármacos , Cloro/química , Corantes , Fibra de Algodão/microbiologia , Fibra de Algodão/efeitos da radiação , Desinfetantes/química , Desinfetantes/efeitos da radiação , Condutividade Elétrica , Contaminação de Equipamentos/prevenção & controle , Gossypium/química , Gossypium/microbiologia , Grafite/química , Halogenação , Interações Hidrofóbicas e Hidrofílicas , Látex/química , Látex/efeitos da radiação , Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Indústria Têxtil/métodos , Raios Ultravioleta , Água/químicaRESUMO
DNA interstrand cross-links, such as those formed by psoralen-UVA irradiation, are highly toxic lesions in both humans and bacteria, with a single lesion being lethal in Escherichia coli. Despite the lack of effective repair, human cancers and bacteria can develop resistance to cross-linking treatments, although the mechanisms of resistance remain poorly defined. Here, we subjected E. coli to repeated psoralen-UVA exposure to isolate three independently derived strains that were >10,000-fold more resistant to this treatment than the parental strain. Analysis of these strains identified gain-of-function mutations in the transcriptional regulator AcrR and the alpha subunit of RNA polymerase that together could account for the resistance of these strains. Resistance conferred by the AcrR mutation is mediated at least in part through the regulation of the AcrAB-TolC efflux pump. Resistance via mutations in the alpha subunit of RNA polymerase occurs through a still-uncharacterized mechanism that has an additive effect with mutations in AcrR. Both acrR and rpoA mutations reduced cross-link formation in vivo. We discuss potential mechanisms in relation to the ability to repair and survive interstrand DNA cross-links. IMPORTANCE Psoralen DNA interstrand cross-links are highly toxic lesions with antimicrobial and anticancer properties. Despite the lack of effective mechanisms for repair, cells can become resistant to cross-linking agents through mechanisms that remain poorly defined. We derived resistant mutants and identified that two gain-of-function mutations in AcrR and the alpha subunit of RNA polymerase confer high levels of resistance to E. coli treated with psoralen-UVA. Resistance conferred by AcrR mutations occurs through regulation of the AcrAB-TolC efflux pump, has an additive effect with RNA polymerase mutations, acts by reducing the formation of cross-links in vivo, and reveals a novel mechanism by which these environmentally and clinically important agents are processed by the cell.
Assuntos
Proteínas de Escherichia coli , Escherichia coli , Humanos , Antibacterianos/efeitos da radiação , DNA , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Ficusina/farmacologia , MutaçãoRESUMO
The production and consumption of halogenated antibiotics, such as florfenicol (FLO), remain high, accompanied by a large amount of antibiotic-containing wastewater, which would induce the potential proliferation and transmission of antibiotic resistance genes (ARGs) in conventional biological systems. This study revealed that the introduction of reductive species (mainly H) by adding sulfite during UV irradiation process accelerated the decomposition rate of FLO, increasing from 0.1379 min-1 in the single UV photolytic system to 0.3375 min-1 in the UV/sulfite system. The enhanced photodecomposition in UV/sulfite system was attributed to the improved dehalogenation performance and additional removal of sulfomethyl group at the site of the benzene ring, which were the representative structures consisting of FLO antibacterial activity. Compared with single UV photolysis, UV/sulfite advanced reduction process saved the light energy requirement by 40 % for the evolutionary suppression of floR, and its corresponding class of ARGs in subsequent biotreatment system was controlled at the level of the negative group. Compared with UV/H2O2 and UV/persulfate systems, the decomposition rate of FLO in the UV/S system was the highest and preserved the corresponding carbon source of the coexisting organic compounds for the potential utilization of microbial metabolism in subsequent biotreatment process. These results demonstrated that UV/sulfite advanced reduction process could be adopted as a promising pretreatment option for the source prevention of representative ARGs proliferation of halogenated antibiotics in subsequent biotreatment process.
Assuntos
Antibacterianos , Águas Residuárias , Antibacterianos/farmacologia , Antibacterianos/efeitos da radiação , Benzeno , Carbono , Proliferação de Células , Resistência Microbiana a Medicamentos/genética , Peróxido de Hidrogênio/química , Oxirredução , Sulfitos , Tianfenicol/análogos & derivados , Raios UltravioletaRESUMO
In this study, a biodegradable photodynamic antibacterial film (Car-Cur) was prepared using casting method with κ-Carrageenan (κ-Car) as film-forming substrate and curcumin-ß-cyclodextrin (Cur-ß-CD) complex as photosensitizer. The comprehensive performance of this Car-Cur film was investigated. The obtained results showed that the concentration of Cur-ß-CD was an important factor determining the properties of film including tensile strength (TS) elongation at break (EB), water vapor permeability (WVP), water content (WC) and thermal stability. When the concentration of Cur-ß-CD is 1%, the film demonstrated the maximum TS and EB, increased thermal stability, with desirable WVP and WC. Furthermore, this film also showed good photodynamic antibacterial potential against Staphylococcus aureus and Escherichia coli upon irradiation of blue LED light. Moreover, the film can be degraded in the soil in one week. In conclusion, our results suggested Car-Cur photodynamic film could be developed as biodegradable antimicrobial packaging material for food preservation.
Assuntos
Antibacterianos , Carragenina , Curcumina , Escherichia coli/efeitos dos fármacos , Fármacos Fotossensibilizantes , Staphylococcus aureus/efeitos dos fármacos , beta-Ciclodextrinas , Antibacterianos/administração & dosagem , Antibacterianos/química , Antibacterianos/efeitos da radiação , Carragenina/administração & dosagem , Carragenina/química , Carragenina/efeitos da radiação , Curcumina/administração & dosagem , Curcumina/química , Curcumina/efeitos da radiação , Escherichia coli/crescimento & desenvolvimento , Embalagem de Alimentos , Temperatura Alta , Luz , Fármacos Fotossensibilizantes/administração & dosagem , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/efeitos da radiação , Staphylococcus aureus/crescimento & desenvolvimento , Vapor , Resistência à Tração , beta-Ciclodextrinas/administração & dosagem , beta-Ciclodextrinas/química , beta-Ciclodextrinas/efeitos da radiaçãoRESUMO
Achieving an efficient and inexpensive bactericidal effect is a key point for the design of antibacterial agent. Recent advances have proved molybdenum disulfide (MoS2) as a promising platform for antimicrobial applications, while the combination of metal nanoparticle would promote the antibacterial efficiency. Nevertheless, the dispersivity, cheapness and safety of metal nanoparticle loaded on MoS2raised some concerns. In this paper, we successfully realized a uniform decoration of copper nanoparticles (CuNPs) on surface of MoS2nanosheets, and the size of CuNPs could be controlled below 5 nm. Under 5 min irradiation of 660 nm visible light, the synthesized CuNPs/MoS2composite demonstrated superior antibacterial performances (almost 100% bacterial killed) towards both Gram-negativeE. coliand Gram-positiveS. aureusover the single component (Cu or MoS2), while the bactericidal effect could last for at least 6 h. The synergism of photodynamic generated hydroxyl radical (·OH), oxidative stress without reactive oxygen species production and the release of Cu ions was considered as the mechanism for the antibacterial properties of CuNPs/MoS2. Our findings provided new insights into the development of two-dimensional antibacterial nanomaterials of high cost performance.
Assuntos
Antibacterianos , Bactérias/efeitos dos fármacos , Cobre , Dissulfetos , Nanopartículas Metálicas , Molibdênio , Antibacterianos/química , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Antibacterianos/efeitos da radiação , Cobre/química , Cobre/farmacocinética , Cobre/farmacologia , Cobre/efeitos da radiação , Dissulfetos/química , Dissulfetos/farmacologia , Dissulfetos/efeitos da radiação , Luz , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Molibdênio/química , Molibdênio/farmacologia , Molibdênio/efeitos da radiação , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Processos FotoquímicosRESUMO
Surgical site infections constitute a major health concern that may be addressed by conferring antibacterial properties to surgical tools and medical devices via functional coatings. Bio-sourced polymers are particularly well-suited to prepare such coatings as they are usually safe and can exhibit intrinsic antibacterial properties or serve as hosts for bactericidal agents. The goal of this Review is to highlight the unique contribution of photochemistry as a green and mild methodology for the development of such bio-based antibacterial materials. Photo-generation and photo-activation of bactericidal materials are illustrated. Recent efforts and current challenges to optimize the sustainability of the process, improve the safety of the materials and extend these strategies to 3D biomaterials are also emphasized.
Assuntos
Antibacterianos/farmacologia , Fotoquímica/métodos , Polímeros/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/efeitos da radiação , Bactérias/efeitos dos fármacos , Produtos Biológicos/química , Produtos Biológicos/efeitos da radiação , Química Verde , Humanos , Luz , Nanopartículas/química , Nanopartículas/efeitos da radiação , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/efeitos da radiação , Polimerização/efeitos da radiação , Polímeros/síntese química , Polímeros/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismoRESUMO
The excessive colonization of Propionibacterium acnes (P. acnes) is responsible for the genesis of acne vulgaris, a common inflammatory disease of skin. However, the conventional anti-acne therapies are always limited by various side effects, drug resistance, and poor skin permeability. Microneedles (MNs) are emerging topical drug delivery systems capable of noninvasively breaking through the skin stratum corneum barrier to efficiently enhance the transdermal drug penetration. Herein, MNs loaded with intelligent pH-sensitive nanoplatforms were constructed for amplified chemo-photodynamic therapy against acne vulgaris, jointly exerting antimicrobial and anti-inflammatory effects. The photosensitizer indocyanine green (ICG) was loaded into the zeolitic imidazolate framework-8 (ZIF-8) to improve its photostability, which would be triggered by 808 nm laser irradiation to generate cytotoxic reactive oxygen species (ROS) to result in oxidative damage and disturbed metabolic activities of P. acnes. In addition to the efficient drug delivery, the ZIF-8 carrier could selectively degrade in response to the acidic microenvironment of acne lesions, and the released Zn2+ also exhibited a potent antimicrobial activity. The fabricated ZIF-8-ICG@MNs presented an outstanding synergistic anti-acne efficiency both in vitro and in vivo. This bioresponsive microneedle patch is expected to be readily adapted as a generalized, modular strategy for noninvasive therapeutics delivery against superficial skin diseases.
Assuntos
Acne Vulgar/tratamento farmacológico , Antibacterianos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Imidazóis/uso terapêutico , Verde de Indocianina/uso terapêutico , Estruturas Metalorgânicas/uso terapêutico , Fármacos Fotossensibilizantes/uso terapêutico , Acne Vulgar/patologia , Animais , Antibacterianos/química , Antibacterianos/efeitos da radiação , Antibacterianos/toxicidade , Anti-Inflamatórios/química , Anti-Inflamatórios/efeitos da radiação , Anti-Inflamatórios/toxicidade , Células HEK293 , Humanos , Imidazóis/química , Imidazóis/efeitos da radiação , Imidazóis/toxicidade , Verde de Indocianina/química , Verde de Indocianina/efeitos da radiação , Verde de Indocianina/toxicidade , Raios Infravermelhos , Masculino , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/efeitos da radiação , Estruturas Metalorgânicas/toxicidade , Camundongos Endogâmicos BALB C , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/efeitos da radiação , Fármacos Fotossensibilizantes/toxicidade , Propionibacterium acnes/efeitos dos fármacos , Ratos , Pele/efeitos dos fármacos , Pele/patologia , Suínos , Zinco/química , Zinco/efeitos da radiação , Zinco/uso terapêutico , Zinco/toxicidadeRESUMO
Biofilms formed from the pathogenic bacteria that attach to the surfaces of biomedical devices and implantable materials result in various persistent and chronic bacterial infections, posing serious threats to human health. Compared to the elimination of matured biofilms, prevention of the formation of biofilms is expected to be a more effective way for the treatment of biofilm-associated infections. Herein, we develop a facile method for endowing diverse substrates with long-term antibiofilm property by deposition of a hybrid film composed of tannic acid/Cu ion (TA/Cu) complex and poly(ethylene glycol) (PEG). In this system, the TA/Cu complex acts as a multifunctional building block with three different roles: (i) as a versatile "glue" with universal adherent property for substrate modification, (ii) as a photothermal biocidal agent for bacterial elimination under irradiation of near-infrared (NIR) laser, and (iii) as a potent linker for immobilization of PEG with inherent antifouling property to inhibit adhesion and accumulation of bacteria. The resulted hybrid film shows negligible cytotoxicity and good histocompatibility and could prevent biofilm formation for at least 15 days in vitro and suppress bacterial infection in vivo, showing great potential for practical applications to solve the biofilm-associated problems of biomedical materials and devices.
Assuntos
Antibacterianos/uso terapêutico , Biofilmes/efeitos dos fármacos , Incrustação Biológica/prevenção & controle , Materiais Revestidos Biocompatíveis/uso terapêutico , Cobre/uso terapêutico , Taninos/uso terapêutico , Animais , Antibacterianos/química , Antibacterianos/efeitos da radiação , Antibacterianos/toxicidade , Aderência Bacteriana/efeitos dos fármacos , Linhagem Celular , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/efeitos da radiação , Materiais Revestidos Biocompatíveis/toxicidade , Cobre/química , Cobre/efeitos da radiação , Cobre/toxicidade , Escherichia coli/efeitos dos fármacos , Raios Infravermelhos , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Terapia Fototérmica , Polietilenoglicóis/química , Polietilenoglicóis/toxicidade , Ratos Sprague-Dawley , Pele/patologia , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Infecções Cutâneas Estafilocócicas/patologia , Staphylococcus aureus/efeitos dos fármacos , Taninos/química , Taninos/efeitos da radiação , Taninos/toxicidadeRESUMO
In this study, we introduced four "claw-like" units of dipicolylamine (DPA) to a tetraphenylethylene (TPE)-based organic molecular cage (DPA-TPE-Cage). Coordinated with Zn2+ ions, the obtained ZnDPA-TPE-Cage exhibited aggregation induced emission (AIE) effects and oxidase-like properties, which endowed it with the ability to selectively image and kill Gram-positive bacteria S. aureus efficiently.
Assuntos
Antibacterianos/farmacologia , Corantes Fluorescentes/farmacologia , Nanopartículas/química , Aminas/química , Aminas/farmacologia , Aminas/efeitos da radiação , Antibacterianos/química , Antibacterianos/efeitos da radiação , Catálise/efeitos da radiação , Membrana Celular/efeitos dos fármacos , Corantes Fluorescentes/química , Corantes Fluorescentes/efeitos da radiação , Luz , Testes de Sensibilidade Microbiana , Nanopartículas/efeitos da radiação , Ácidos Picolínicos/química , Ácidos Picolínicos/farmacologia , Ácidos Picolínicos/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Estilbenos/química , Estilbenos/farmacologia , Estilbenos/efeitos da radiação , Zinco/química , Zinco/farmacologia , Zinco/efeitos da radiaçãoRESUMO
In this work, we developed the first 3D-printed polyetheretherketone (PEEK)-based bone scaffold with multi-functions targeting challenging bone diseases such as osteosarcoma and osteomyelitis. A 3D-printed PEEK/graphene nanocomposite scaffold was deposited with a drug-laden (antibiotics and/or anti-cancer drugs) hydroxyapatite coating. The graphene nanosheets within the scaffold served as effective photothermal agents that endowed the scaffold with on-demand photothermal conversion function under near-infrared laser irradiation. The bioactive hydroxyapatite coating significantly boosted the stem cell proliferation in vitro and promoted new bone growth in vivo. The presence of antibiotics and anti-cancer drugs enabled eradication of drug-resistant bacteria and ablation of osteosarcoma cancer cells, the treatment efficacy of which can be further enhanced by on-demand laser-induced heating. The promising results demonstrate the strong potential of our multi-functional scaffold in applications such as bone defect repair and multimodal treatment of osteosarcoma and osteomyelitis.
Assuntos
Antibacterianos/uso terapêutico , Antineoplásicos/uso terapêutico , Benzofenonas/química , Osteomielite/tratamento farmacológico , Osteossarcoma/tratamento farmacológico , Polímeros/química , Alicerces Teciduais/química , Animais , Antibacterianos/efeitos da radiação , Antineoplásicos/efeitos da radiação , Regeneração Óssea/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cisplatino/uso terapêutico , Terapia Combinada , Durapatita/química , Durapatita/uso terapêutico , Grafite/química , Grafite/efeitos da radiação , Grafite/uso terapêutico , Humanos , Raios Infravermelhos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanocompostos/química , Nanocompostos/efeitos da radiação , Nanocompostos/uso terapêutico , Terapia Fototérmica , Impressão Tridimensional , Compostos de Amônio Quaternário/uso terapêutico , Ratos Sprague-DawleyRESUMO
Two-dimensional material titanium carbide (Ti3C2Tx MXene) has been widely used for building diverse functional materials; however, the disadvantages of unsatisfactory yield and low concentration during the preparation process generally limit its large-scale promotion. In the present work, an MXene dispersion with enhanced yield (90%), high concentration (45 mg/mL), and excellent dispersibility was successfully prepared. Subsequently, the active MXene nanosheets were effectively in situ deposition onto the silk fiber by means of dip-coating, relying on van der Waals forces and hydrogen bonds. The obtained MXene-decorated silk fabric (MXene@silk) exhibits satisfactory electrical conductivity (170 mS/cm), excellent photothermal and electrothermal conversion properties, especially dual-drive energy conversion, rapid thermal responses, and long-term functional stability. Furthermore, UV protection factor of the fabric, and its antibacterial efficiency against Gram-negative Escherichia coli (E. coli) within 20 min of contact reach over 110 and 99%, respectively, demonstrating remarkable UV resistance and rapid photothermal antibacterial ability. Meanwhile, the fabric of MXene@silk still retains the original characteristics of breathability, softness, and skin-friendly properties compared to the untreated. The multifunctional fabric constructed through a facile and high-yield strategy shows a noticeable potential applying to smart textiles to meet people's multipurpose needs in the future.
Assuntos
Antibacterianos/farmacologia , Nanoestruturas/química , Seda/química , Têxteis , Dispositivos Eletrônicos Vestíveis , Antibacterianos/química , Antibacterianos/efeitos da radiação , Condutividade Elétrica , Escherichia coli/efeitos dos fármacos , Calefação , Luz , Nanoestruturas/efeitos da radiação , Seda/efeitos da radiação , Têxteis/efeitos da radiação , Titânio/química , Titânio/farmacologia , Titânio/efeitos da radiaçãoRESUMO
Solar-driven steam generation has been recognized as a sustainable and low-cost solution to freshwater scarcity using abundant solar energy. To harvest freshwater, various interfacial evaporators with rational designs of photothermal materials and structures have been developed concentrating on increasing the evaporation rate in the past few years. However, pathogenic microorganism accumulation on the evaporators by long-duration contact with natural water resources may lead to the deterioration of water transportation and the reduction of the evaporation rate. Here, we develop cationic photothermal hydrogels (CPHs) based on [2-(methacryloyloxy)ethyl]trimethylammonium chloride (METAC) and photothermal polypyrrole (PPy) with bacteria-inhibiting capability for freshwater production via solar-driven steam generation. A rapid water evaporation rate of 1.592 kg m-2 h-1 under simulated solar irradiation is achieved with CPHs floating on the water surface. Furthermore, we find that CPHs possess nearly 100% antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The significant bacteria-inhibiting capability is mainly attributed to the large number of ammonium groups on the CPH network. Moreover, we show that CPHs exhibit good applicability with stable evaporation in natural lake water over 2 weeks, and the number of bacteria in purified lake water is significantly reduced. The device based on CPHs can achieve â¼0.49 kg m-2 h-1 freshwater production from lake water under natural sunlight. This study provides an attractive strategy for the evaporator to inhibit biological contamination and a potential way for long-term stable freshwater production from natural water resources in practical application.
Assuntos
Antibacterianos/farmacologia , Água Doce/química , Hidrogéis/farmacologia , Vapor , Antibacterianos/química , Antibacterianos/efeitos da radiação , Escherichia coli/química , Hidrogéis/química , Hidrogéis/efeitos da radiação , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Metacrilatos/farmacologia , Polímeros/química , Polímeros/farmacologia , Polímeros/efeitos da radiação , Pirróis/química , Pirróis/farmacologia , Pirróis/efeitos da radiação , Energia Solar , Staphylococcus aureus/efeitos dos fármacos , Luz Solar , Purificação da Água/métodosRESUMO
Photodynamic therapy (PDT) is a potential approach to resolve antibiotic resistance, and phenylene/thiophene-ethynylene oligomers have been widely studied as effective antibacterial reagents. Oligomers with thiophene moieties usually exhibit good antibacterial activity under light irradiation and dark conditions. In the previous study, we verified that neutral oligo-p-phenylene-ethynylenes (OPEs) exhibit better antibacterial activity than the corresponding cationic ones; however, whether this regular pattern also operates in other kinds of oligomers such as oligo-thiophene-ethynylene (OTE) is unknown. Also, the antibacterial activity comparison of OTEs bearing cyclic and acyclic amino groups will offer useful information to further understand the role of amino groups in the antibacterial process and guide the antibacterial reagent design as amino groups affect the antibacterial activity a lot. We synthesized four OTEs bearing neutral or cationic, cyclic, or acyclic amino groups and studied their antibacterial activity in detail. The experimental results indicated that the OTEs exhibited better antibacterial activity than the OPEs, the neutral OTEs exhibited better antibacterial activity in most cases, and OTEs bearing cyclic amino groups exhibited better antibacterial activity than those bearing acyclic ones in most cases. This study provides useful guidelines for further antibacterial reagent design and investigations.
Assuntos
Alcinos/farmacologia , Antibacterianos/farmacologia , Tiofenos/farmacologia , Alcinos/química , Alcinos/efeitos da radiação , Alcinos/toxicidade , Antibacterianos/química , Antibacterianos/efeitos da radiação , Antibacterianos/toxicidade , Linhagem Celular , Escherichia coli/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Luz , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Tiofenos/química , Tiofenos/efeitos da radiação , Tiofenos/toxicidadeRESUMO
Antibodies are recognition molecules that can bind to diverse targets ranging from pathogens to small analytes with high binding affinity and specificity, making them widely employed for sensing and therapy. However, antibodies have limitations of low stability, long production time, short shelf life, and high cost. Here, we report a facile approach for the design of luminescent artificial antibodies with nonbiological polymeric recognition phases for the sensitive detection, rapid identification, and effective inactivation of pathogenic bacteria. Transition-metal dichalcogenide (TMD) nanosheets with a neutral dextran phase at the interfaces selectively recognized S. aureus, whereas the nanosheets bearing a carboxymethylated dextran phase selectively recognized E. coli O157:H7 with high binding affinity. The bacterial binding sites recognized by the artificial antibodies were thoroughly identified by experiments and molecular dynamics simulations, revealing the significance of their multivalent interactions with the bacterial membrane components for selective recognition. The luminescent WS2 artificial antibodies could rapidly detect the bacteria at a single copy from human serum without any purification and amplification. Moreover, the MoSe2 artificial antibodies selectively killed the pathogenic bacteria in the wounds of infected mice under light irradiation, leading to effective wound healing. This work demonstrates the potential of TMD artificial antibodies as an alternative to antibodies for sensing and therapy.
Assuntos
Antibacterianos/uso terapêutico , Infecções por Escherichia coli/tratamento farmacológico , Substâncias Luminescentes/uso terapêutico , Nanoestruturas/uso terapêutico , Animais , Antibacterianos/química , Antibacterianos/efeitos da radiação , Dextranos/química , Escherichia coli O157/efeitos dos fármacos , Escherichia coli O157/isolamento & purificação , Luz , Substâncias Luminescentes/química , Substâncias Luminescentes/efeitos da radiação , Camundongos , Simulação de Dinâmica Molecular , Molibdênio/química , Molibdênio/efeitos da radiação , Molibdênio/uso terapêutico , Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Terapia Fototérmica , Compostos de Selênio/química , Compostos de Selênio/efeitos da radiação , Compostos de Selênio/uso terapêutico , Pele/microbiologia , Análise Espectral Raman , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Sulfetos/química , Sulfetos/efeitos da radiação , Sulfetos/uso terapêutico , Compostos de Tungstênio/química , Compostos de Tungstênio/efeitos da radiação , Compostos de Tungstênio/uso terapêutico , Cicatrização/efeitos dos fármacosRESUMO
Combined therapeutic strategies for bacterial infection have attracted worldwide attention owing to their faster and more effective therapy with fewer side effects compared with monotherapy. In this work, gold-platinum nanodots (AuPtNDs) are simply and quickly synthesized by a one-step method. They not only exhibit powerful peroxidase-like activity but also confer a higher affinity for hydrogen peroxide (H2O2), which is 3.4 times that of horseradish peroxidase. Under 808 nm laser irradiation, AuPtNDs also have excellent photothermal conversion efficiency (50.53%) and strong photothermal stability. Excitingly, they can combat bacterial infection through the combination of chemodynamic and photothermal therapy. In vitro antibacterial results show that the combined antibacterial strategy has a broad-spectrum antibacterial property against both Escherichia coli (Gram negative, 97.1%) and Staphylococcus aureus (Gram positive, 99.3%). Animal experiments further show that nanodots can effectively promote the healing of bacterial infection wounds. In addition, owing to good biocompatibility and low toxicity, they are hardly traceable in the main organs of mice, which indicates that they can be well excreted through metabolism. These results reveal the application potential of AuPtNDs as a simple and magic multifunctional nanoparticle in antibacterial therapy and open up new applications for clinical anti-infective therapy in the near future.
Assuntos
Antibacterianos/uso terapêutico , Pontos Quânticos/uso terapêutico , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Animais , Antibacterianos/síntese química , Antibacterianos/efeitos da radiação , Antibacterianos/toxicidade , Catálise , Escherichia coli/efeitos dos fármacos , Ouro/química , Ouro/efeitos da radiação , Ouro/uso terapêutico , Ouro/toxicidade , Células HEK293 , Humanos , Raios Infravermelhos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Terapia Fototérmica , Platina/química , Platina/efeitos da radiação , Platina/uso terapêutico , Platina/toxicidade , Pontos Quânticos/química , Pontos Quânticos/efeitos da radiação , Pontos Quânticos/toxicidade , Staphylococcus aureus/efeitos dos fármacos , Cicatrização/efeitos dos fármacosRESUMO
To promote bactericidal activity, improve photostability and safety, novel antibacterial nanoparticle system based on photodynamic action (PDA) was prepared here through conjugation of photosensitizer hematoporphyrin (HP) onto carboxymethyl chitosan (CMCS) via amide linkage and followed by ultrasonic treatment. The system was stable in PBS (pH 7.4) and could effectively inhibit the photodegradation of conjugated HP because of aggregation-caused quenching effect. ROS produced by the conjugated HP under light exposure could change the structure of nanoparticles by oxidizing the CMCS skeleton and thereby significantly promote the photodynamic activity of HP and its photodynamic activity after 6 h was higher than that of HP·2HCl under the same conditions. Antibacterial experiments showed that CMCS-HP nanoparticles had excellent photodynamic antibacterial activity, and the bacterial inhibition rates after 60 min of light exposure were greater than 97%. Safety evaluation exhibited that the nanoparticles were safe to mammalian cells, showing great potential for antibacterial therapy.
Assuntos
Antibacterianos/farmacologia , Quitosana/análogos & derivados , Hematoporfirinas/farmacologia , Nanopartículas/química , Fármacos Fotossensibilizantes/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/efeitos da radiação , Antibacterianos/toxicidade , Quitosana/síntese química , Quitosana/farmacologia , Quitosana/efeitos da radiação , Quitosana/toxicidade , Escherichia coli/efeitos dos fármacos , Hematoporfirinas/síntese química , Hematoporfirinas/efeitos da radiação , Hematoporfirinas/toxicidade , Luz , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Nanopartículas/efeitos da radiação , Nanopartículas/toxicidade , Tamanho da Partícula , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/efeitos da radiação , Fármacos Fotossensibilizantes/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus , Tensoativos/síntese química , Tensoativos/farmacologia , Tensoativos/efeitos da radiação , Tensoativos/toxicidadeRESUMO
In the present study, the novel Ag/cellulose nanocrystal (CNC)-doped CeO2 quantum dots (QDs) with highly efficient catalytic performance were synthesized using one pot co-precipitation technique, which were then applied in the degradation of methylene blue and ciprofloxacin (MBCF) in wastewater. Catalytic activity against MBCF dye was significantly reduced (99.3%) for (4%) Ag dopant concentration in acidic medium. For Ag/CNC-doped CeO2 vast inhibition domain of G-ve was significantly confirmed as (5.25-11.70 mm) and (7.15-13.60 mm), while medium- to high-concentration of CNC levels were calculated for G + ve (0.95 nm, 1.65 mm), respectively. Overall, (4%) Ag/CNC-doped CeO2 revealed significant antimicrobial activity against G-ve relative to G + ve at both concentrations, respectively. Furthermore, in silico molecular docking studies were performed against selected enzyme targets dihydrofolate reductase (DHFR), dihydropteroate synthase (DHPS), and DNA gyrase belonging to folate and nucleic acid biosynthetic pathway, respectively to rationalize possible mechanism behind bactericidal potential of CNC-CeO2 and Ag/CNC-CeO2.
Assuntos
Antibacterianos/farmacologia , Celulose/química , Cério/química , Corantes/química , Pontos Quânticos/química , Prata/farmacologia , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/efeitos da radiação , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Catálise/efeitos da radiação , Celulose/síntese química , Celulose/metabolismo , Celulose/efeitos da radiação , Cério/metabolismo , Cério/efeitos da radiação , Ciprofloxacina/química , DNA Girase/química , DNA Girase/metabolismo , Di-Hidropteroato Sintase/química , Di-Hidropteroato Sintase/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Luz , Azul de Metileno/química , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Ligação Proteica , Pontos Quânticos/metabolismo , Pontos Quânticos/efeitos da radiação , Prata/química , Prata/metabolismo , Prata/efeitos da radiação , Staphylococcus aureus/efeitos dos fármacos , Tetra-Hidrofolato Desidrogenase/química , Tetra-Hidrofolato Desidrogenase/metabolismo , Poluentes Químicos da Água/química , Purificação da Água/métodosRESUMO
Hypoxia, a common characteristic of bacterial infections, is known to be closely associated with the emergence of multidrug-resistant bacteria, which hastens the need to develop advanced microbicides and antibacterial techniques. Photodynamic therapy is a promising strategy to reduce bacterial antibiotic resistance and employs photosensitizers, excitation light sources, and sufficient oxygen to generate toxic reactive oxygen species (ROS). The inherent limitation of PDT is that the generation of ROS is restricted by the hypoxic microenvironment in infection sites. Here, an oxygen self-supplying nanotherapeutic is developed to enhance antibacterial activity against multidrug-resistant bacteria on the basis of fluorinated boron dipyrromethene (BODIPY)-based glycomimetics. The nanotherapeutic not only could capture the bacteria efficiently but also was able to act as an oxygen carrier to relieve the hypoxic microenvironment of bacterial infections, thus achieving enhanced PDT efficacy. In a Pseudomonas aeruginosa infection of a rat cornea, typical administration of the nanotherapeutic decreased the infiltrate and showed a faster healing capacity in comparison with BODIPY-based glycomimetics. Self-supplying oxygen nanotherapeutics that relieve the hypoxic microenvironment and interfere with bacterial colonization have been shown to be a promising candidate for the management of drug-resistant microbial keratitis.
Assuntos
Antibacterianos/uso terapêutico , Infecções Oculares Bacterianas/tratamento farmacológico , Hipóxia/tratamento farmacológico , Ceratite/tratamento farmacológico , Nanopartículas/uso terapêutico , Oxigênio/metabolismo , Animais , Antibacterianos/química , Antibacterianos/efeitos da radiação , Biofilmes/efeitos dos fármacos , Compostos de Boro/química , Compostos de Boro/efeitos da radiação , Compostos de Boro/uso terapêutico , Córnea/metabolismo , Córnea/microbiologia , Córnea/patologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Infecções Oculares Bacterianas/metabolismo , Infecções Oculares Bacterianas/patologia , Hipóxia/metabolismo , Hipóxia/patologia , Ceratite/metabolismo , Ceratite/patologia , Luz , Camundongos , Células NIH 3T3 , Nanopartículas/química , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/efeitos da radiação , Fármacos Fotossensibilizantes/uso terapêutico , Ácidos Polimetacrílicos/química , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/metabolismo , Infecções por Pseudomonas/patologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , RatosRESUMO
Compared with high molecular weight chitosan (HMWC), low molecular weight chitosan (LMWC) has better solubility and biological activity. However, there is no quick and environmentally friendly to prepare low molecular chitosan. In this study, microwave induced plasma desorption/ionization (MIPDI) was used for the first time to prepare LMWC through the degradation processes of HMWC. The results showed that MIPDI has the most abundant âOH content at the gas-liquid interface, and the active particles represented by âOH can degrade chitosan with a molecular weight of 540 KDa into soluble chitosan (≤ 10 KDa), and the yield of soluble chitosan can reach 61% in 60 min. Moreover, a series of characterization results showed that the chain structure and crystal structure gradually degraded as the treatment time increased while the chemical structure of chitosan did not change significantly. Antibacterial experiments also indicated that the antimicrobial property of LMWC obtained by MIPDI degradation was improved. In short, this method has proven to be a new, fast and green processing method for the preparation of low molecular chitosan.
Assuntos
Antibacterianos/efeitos da radiação , Quitosana/efeitos da radiação , Química Verde , Radical Hidroxila/química , Micro-Ondas , Antibacterianos/química , Antibacterianos/farmacologia , Quitosana/química , Quitosana/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Peso Molecular , Solubilidade , Fatores de TempoRESUMO
Owing to the rise in prevalence of multidrug-resistant pathogens attributed to the overuse of antibiotics, infectious diseases caused by the transmission of microbes from contaminated surfaces to new hosts are an ever-increasing threat to public health. Thus, novel materials that can stem this crisis, while also functioning via multiple antimicrobial mechanisms so that pathogens are unable to develop resistance to them, are in urgent need. Toward this goal, in this work, we developed in situ grown bacterial cellulose/MoS2-chitosan nanocomposite materials (termed BC/MoS2-CS) that utilize synergistic membrane disruption and photodynamic and photothermal antibacterial activities to achieve more efficient bactericidal activity. The BC/MoS2-CS nanocomposite exhibited excellent antibacterial efficacy, achieving 99.998% (4.7 log units) and 99.988% (3.9 log units) photoinactivation of Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, respectively, under visible-light illumination (xenon lamp, 500 W, λ ≥ 420 nm, and 30 min). Mechanistic studies revealed that the use of cationic chitosan likely facilitated bacterial membrane disruption and/or permeability, with hyperthermia (photothermal) and reactive oxygen species (photodynamic) leading to synergistic pathogen inactivation upon visible-light illumination. No mammalian cell cytotoxicity was observed for the BC/MoS2-CS membrane, suggesting that such composite nanomaterials are attractive as functional materials for infection control applications.