RESUMO
The development of drug-resistant microorganisms is taking a heavy toll on the biomedical world. Clinical infections are costly and becoming increasingly dangerous as bacteria that once responded to standard antibiotic treatment are developing resistance mechanisms that require innovative treatment strategies. Nitric oxide (NO) is a gaseous molecule produced endogenously that has shown potent antibacterial capabilities in numerous research studies. Its multimechanistic antibacterial methods prevent the development of resistance and have shown potential as an alternative to antibiotics. However, there has yet to be a direct comparison study evaluating the antibacterial properties of NO against antibiotic susceptible and antibiotic-resistant clinically isolated bacterial strains. Herein, standardized lab and clinically isolated drug-resistant bacterial strains are compared side-by-side for growth and viability following treatment with NO released from S-nitrosoglutathione (GSNO), an NO donor molecule. Evaluation of growth kinetics revealed complete killing of E. coli lab and clinical strains at 17.5 mM GSNO, though 15 mM displayed >50% killing and significantly reduced metabolic activity, with greater dose dependence for membrane permeability. Clinical P. aeruginosa showed greater susceptibility to GSNO during growth curve studies, but metabolic activity and membrane permeability demonstrated similar effects for 12.5 mM GSNO treatment of lab and clinical strains. MRSA lab and clinical strains exhibited total killing at 17.5 mM treatment, though metabolic activity was decreased, and membrane permeation began at 12.5 mM for both strains. Lastly, both S. epidermidis strains were killed by 15 mM GSNO, with sensitivities in metabolic activity and membrane permeability at 12.5 mM GSNO. The mirrored antibacterial effects seen by the lab and clinical strains of two Gram-negative and two Gram-positive bacteria reveal the translational success of NO as an antibacterial therapy and potential alternative to standard antibiotic treatment.
Assuntos
Antibacterianos , Escherichia coli , Óxido Nítrico , Óxido Nítrico/farmacologia , Óxido Nítrico/química , Óxido Nítrico/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Humanos , S-Nitrosoglutationa/farmacologia , S-Nitrosoglutationa/química , Doadores de Óxido Nítrico/farmacologia , Doadores de Óxido Nítrico/química , Farmacorresistência Bacteriana/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimentoRESUMO
Blood-contacting medical devices routinely fail from the cascading effects of biofouling toward infection and thrombosis. Nitric oxide (NO) is an integral part of endothelial homeostasis, maintaining platelet quiescence and facilitating oxidative/nitrosative stress against pathogens. Recently, it is shown that the surface evolution of NO can mediate cell-surface interactions. However, this technique alone cannot prevent the biofouling inherent in device failure with dynamic blood-contacting applications. This work proposes an endothelium-mimicking surface design pairing controlled NO release with an inherently antifouling polyethylene glycol interface (NO+PEG). This simple, robust, and scalable platform develops surface-localized NO availability with surface hydration, leading to a significant reduction in protein adsorption as well as bacteria/platelet adhesion. Further in vivo thrombogenicity studies show a decrease in thrombus formation on NO+PEG interfaces, with preservation of circulating platelet and white blood cell counts, maintenance of activated clotting time, and reduced coagulation cascade activation. It is anticipated that this bio-inspired surface design will enable a facile alternative to existing surface technologies to address clinical manifestations of infection and thrombosis in dynamic blood-contacting environments.
RESUMO
Wound infection and excessive blood loss are the two major challenges associated with trauma injuries that account for 10% of annual deaths in the United States. Nitric oxide (NO) is a gasotransmitter cell signaling molecule that plays a crucial role in the natural wound healing process due to its antibacterial, anti-inflammatory, cell proliferation, and tissue remodeling abilities. Tranexamic acid (TXA), a prothrombotic agent, has been used topically and systemically to control blood loss in reported cases of epistaxis and combat-related trauma injuries. Its properties could be incorporated in wound dressings to induce immediate clot formation, which is a key factor in controlling excessive blood loss. This study introduces a novel, instant clot-forming NO-releasing dressing, and fabricated using a strategic bi-layer configuration. The layer adjacent to the wound was designed with TXA suspended on a resinous bed of propolis, which is a natural bioadhesive possessing antibacterial and anti-inflammatory properties. The base layer, located furthest away from the wound, has an NO donor, S-nitroso-N-acetylpenicillamine (SNAP), embedded in a polymeric bed of Carbosil®, a copolymer of polycarbonate urethane and silicone. Propolis was integrated with a uniform layer of TXA in variable concentrations: 2.5, 5.0, and 7.5 vol % of propolis. This design of the TXA-SNAP-propolis (T-SP) wound dressing allows TXA to form a more stable clot by preventing the lysis of fibrin. The lactate dehydrogenase-based platelet adhesion assay showed an increase in fibrin activation with 7.5% T-SP as compared with control within the first 15 min of its application. A scanning electron microscope (SEM) confirmed the presence of a dense fibrin network stabilizing the clot for fabricated dressing. The antibacterial activity of NO and propolis resulted in a 98.9 ± 1% and 99.4 ± 1% reduction in the colony-forming unit of Staphylococcus aureus and multidrug-resistant Acinetobacter baumannii, respectively, which puts forward the fabricated dressing as an emergency first aid for traumatic injuries, preventing excessive blood loss and soil-borne infections.
RESUMO
Biomedical devices are vulnerable to infections and biofilm formation, leading to extended hospital stays, high expenditure, and increased mortality. Infections are clinically treated via the administration of systemic antibiotics, leading to the development of antibiotic resistance. A multimechanistic strategy is needed to design an effective biomaterial with broad-spectrum antibacterial potential. Recent approaches have investigated the fabrication of innately antimicrobial biomedical device surfaces in the hope of making the antibiotic treatment obsolete. Herein, we report a novel fabrication strategy combining antibacterial nitric oxide (NO) with an antibiofilm agent N-acetyl cysteine (NAC) on a polyvinyl chloride surface using polycationic polyethylenimine (PEI) as a linker. The designed biomaterial could release NO for at least 7 days with minimal NO donor leaching under physiological conditions. The proposed surface technology significantly reduced the viability of Gram-negative Escherichia coli (>97%) and Gram-positive Staphylococcus aureus (>99%) bacteria in both adhered and planktonic forms in a 24 h antibacterial assay. The composites also exhibited a significant reduction in biomass and extra polymeric substance accumulation in a dynamic environment over 72 h. Overall, these results indicate that the proposed combination of the NO donor with mucolytic NAC on a polymer surface efficiently resists microbial adhesion and can be used to prevent device-associated biofilm formation.
Assuntos
Acetilcisteína , Antibacterianos , Biofilmes , Escherichia coli , Óxido Nítrico , Staphylococcus aureus , Acetilcisteína/química , Acetilcisteína/farmacologia , Óxido Nítrico/química , Óxido Nítrico/metabolismo , Óxido Nítrico/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Biofilmes/efeitos dos fármacos , Polietilenoimina/química , Polietilenoimina/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Testes de Sensibilidade Microbiana , Cloreto de Polivinila/química , Doadores de Óxido Nítrico/química , Doadores de Óxido Nítrico/farmacologiaRESUMO
Bacterial biofilms play a central role in the development and progression of periodontitis, a chronic inflammatory condition that affects the oral cavity. One solution to current treatment constraints is using nitric oxide (NO)âwith inherent antimicrobial properties. In this study, an antimicrobial coating is developed from the NO donor S-nitroso-N-acetylpenicillamine (SNAP) embedded within polyethylene glycol (PEG) to prevent periodontitis. The SNAP-PEG coating design enabled a controlled NO release, achieving tunable NO levels for more than 24 h. Testing the SNAP-PEG composite on dental floss showed its effectiveness as a uniform and bioactive coating. The coating exhibited antibacterial properties against Streptococcus mutans and Escherichia coli, with inhibition zones measuring up to 7.50 ± 0.28 and 14.80 ± 0.46 mm2, respectively. Furthermore, SNAP-PEG coating materials were found to be stable when stored at room temperature, with 93.65% of SNAP remaining after 28 d. The coatings were biocompatible against HGF and hFOB 1.19 cells through a 24 h controlled release study. This study presents a facile method to utilize controlled NO release with dental antimicrobial coatings comprising SNAP-PEG. This coating can be easily applied to various substrates, providing a user-friendly approach for targeted self-care in managing gingival infections associated with periodontitis.
Assuntos
Antibacterianos , Materiais Revestidos Biocompatíveis , Escherichia coli , Teste de Materiais , Óxido Nítrico , Streptococcus mutans , Streptococcus mutans/efeitos dos fármacos , Óxido Nítrico/química , Óxido Nítrico/metabolismo , Escherichia coli/efeitos dos fármacos , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Biofilmes/efeitos dos fármacos , S-Nitroso-N-Acetilpenicilamina/química , S-Nitroso-N-Acetilpenicilamina/farmacologia , Propriedades de Superfície , Periodontite/tratamento farmacológico , Periodontite/microbiologia , Gengiva/citologiaRESUMO
Of the 27 million surgeries performed in the United States each year, a reported 2.6% result in a surgical site infection (SSI), and Staphylococci species are commonly the culprit. Alternative therapies, such as nitric oxide (NO)-releasing biomaterials, are being developed to address this issue. NO is a potent antimicrobial agent with several modes of action, including oxidative and nitrosative damage, disruption of bacterial membranes, and dispersion of biofilms. For targeted antibacterial effects, NO is delivered by exogenous donor molecules, like S-nitroso-N-acetylpenicillamine (SNAP). Herein, the impregnation of SNAP into poly(lactic-co-glycolic acid) (PLGA) for SSI prevention is reported for the first time. The NO-releasing PLGA copolymer is fabricated and characterized by donor molecule loading, leaching, and the amount remaining after ethylene oxide sterilization. The swelling ratio, water uptake, static water contact angle, and tensile strength are also investigated. Furthermore, its cytocompatibility is tested against 3T3 mouse fibroblast cells, and its antimicrobial efficacy is assessed against multiple Staphylococci strains. Overall, the NO-releasing PLGA copolymer holds promise as a suture material for eradicating surgical site infections caused by Staphylococci strains. SNAP impregnation affords robust antibacterial properties while maintaining the cytocompatibility and mechanical integrity.
Assuntos
Antibacterianos , Materiais Biocompatíveis , Teste de Materiais , Óxido Nítrico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Infecção da Ferida Cirúrgica , Suturas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Infecção da Ferida Cirúrgica/prevenção & controle , Infecção da Ferida Cirúrgica/tratamento farmacológico , Infecção da Ferida Cirúrgica/microbiologia , Óxido Nítrico/química , Óxido Nítrico/metabolismo , Camundongos , Antibacterianos/farmacologia , Antibacterianos/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/prevenção & controle , Tamanho da Partícula , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus/efeitos dos fármacosRESUMO
Nitric oxide (NO)-release from polymer metal composites is achieved through the incorporation of NO donors such as S-nitrosothiols (RSNO). Several studies have shown that metal nanoparticles catalytically decompose RSNO to release NO. In polymer composites, the NO surface flux from the surface can be modulated by the application of metal nanoparticles with a varying degree of catalytic activity. In this study, we compare the NO-releasing polymer composite design strategy - demonstrating how different ways of incorporating RSNO and metal nanoparticles can affect NO flux, donor leaching, or biological activity of the films. The first approach included blending both the RSNO and metal nanoparticle in the matrix (non-layered), while the second approach involved dip-coating metal nanoparticle/polymer layer on the RSNO-containing polymer composite (layered). Secondly, we compare both designs with respect to metal nanoparticles, including iron (Fe), copper (Cu), nickel (Ni), zinc (Zn), and silver (Ag). Differential NO surface flux is observed for each metal nanoparticle, with the Cu-containing polymer composites showing the highest flux for layered composites, whereas Fe demonstrated the highest NO flux for non-layered composites in 24 h. Additionally, a comparative study on NO flux modulation via the choice of metal nanoparticles is shown. Furthermore, mouse fibroblast cell viability when exposed to leachates from the polymer metal composites was dependent on (1) the design of the polymer composite where the layered approach performed better than non-layered composites (2) diffusion of metal nanoparticles from the composites plays a key role. Antibacterial activity on methicillin-resistant Staphylococcus aureus was also dependent on individual metal nanoparticles and flux levels in a 24 h in vitro CDC bioreactor study. Therefore, the study establishes the need for a layered polymer metal composite strategy that synergizes NO flux without negatively affecting biocompatibility.
RESUMO
An increasing number of studies have shown that the local release of nitric oxide (NO) from hydrogels stimulates tissue regeneration by modulating cell proliferation, angiogenesis, and inflammation. The potential biomedical uses of NO-releasing hydrogels can be expanded by enabling their application in a fluid state, followed by controlled gelation triggered by an external factor. In this study, we engineered a hydrogel composed of methacrylated hyaluronic acid (HAGMA) and thiolated gelatin (GELSH) with the capacity for in situ photo-cross-linking, coupled with localized NO release. To ensure a gradual and sustained NO release, we charged the hydrogels with poly(l-lactic-co-glycolic acid) (PLGA) nanoparticles functionalized with S-nitrosoglutathione (GSNO), safeguarding SNO group integrity during photo-cross-linking. The formation of thiol-ene bonds via the reaction between GELSH's thiol groups and HAGMA's vinyl groups substantially accelerated gelation (by a factor of 6) and increased the elastic modulus of hydrated hydrogels (by 1.9-2.4 times). HAGMA/GELSH hydrogels consistently released NO over a 14 day duration, with the release of NO depending on the hydrogels' equilibrium swelling degree, determined by the GELSH-to-HAGMA ratio. Biocompatibility assessments confirmed the suitability of these hydrogels for biological applications as they display low cytotoxicity and stimulated fibroblast adhesion and proliferation. In conclusion, in situ photo-cross-linkable HAGMA/GELSH hydrogels, loaded with PLGA-GSNO nanoparticles, present a promising avenue for achieving localized and sustained NO delivery in tissue regeneration applications.
Assuntos
Gelatina , Ácido Hialurônico , Ácido Hialurônico/química , Gelatina/química , Óxido Nítrico , Hidrogéis/farmacologia , Hidrogéis/química , Compostos de Sulfidrila/químicaRESUMO
Hydrogels provide a plethora of advantages to biomedical treatments due to their highly hydrophilic nature and tissue-like mechanical properties. Additionally, the numerous and widespread endogenous roles of nitric oxide have led to an eruption in research developing biomimetic solutions to the many challenges the biomedical world faces. Though many design factors and fabrication details must be considered, utilizing hydrogels as nitric oxide delivery vehicles provides promising materials in several applications. Such applications include cardiovascular therapy, vasodilation and angiogenesis, antimicrobial treatments, wound dressings, and stem cell research. Herein, a recent update on the progress of NO-releasing hydrogels is presented in depth. In addition, considerations for the design and fabrication of hydrogels and specific biomedical applications of nitric oxide-releasing hydrogels are discussed.
RESUMO
Antibiotic lock therapy (ALT) is standard clinical practice for treating bacteremia linked with catheter-related bloodstream infections (CRBSIs). However, this strategy frequently fails against multi-drug-resistant bacteria in clinical settings. In this study, a novel approach to utilize a nitric oxide (NO) donor S-nitroso-N-acetyl-penicillamine (SNAP)-conjugated to ampicillin antibiotic (namely SNAPicillin) as a catheter lock solution is presented. The conjugate of two antimicrobial agents is anticipated to overcome the challenges of bacterial infection caused by antibiotic-resistant bacteria in ALT applications. Nitric oxide release from the SNAPicillin lock solution at varying concentrations was measured at 0 and 24 h time points in a catheter model system, which revealed tunable NO release at physiological levels. The clinical strains of E. coli (CDC AR-0089) and S. marcescens (CDC AR-0099) were screened using a zone of inhibition assay against standard antibiotics which confirmed the antibiotic resistance in bacteria. The minimum inhibitory concentration (MIC) testing of SNAPicillin unveiled the lowest MIC value for SNAPicillin against both E. coli and S. marcescens (1 and 2 mM of SNAPicillin, respectively) with an 8.24- and 4.28-log reduction in bacterial load compared to controls, respectively. In addition, while the ampicillin-treated biofilm demonstrated resistance toward the antibiotic, SNAPicillin led to >99% reduction in exterminating biofilm buildup on polymeric catheter surfaces. Lastly, the SNAPicillin lock solution was determined to be biocompatible via hemolysis and cell compatibility studies. Together, these results emphasize the promising potential of SNAPicillin lock solution with the dual-action of NO and ampicillin in overcoming bacterial challenges on medical devices like central venous catheters and other medical device interfaces.
Assuntos
Anti-Infecciosos , Infecções Relacionadas a Cateter , Humanos , Antibacterianos , Óxido Nítrico , Escherichia coli , Infecções Relacionadas a Cateter/tratamento farmacológico , Infecções Relacionadas a Cateter/prevenção & controle , Infecções Relacionadas a Cateter/microbiologia , Ampicilina/farmacologia , Anti-Infecciosos/uso terapêutico , Bactérias , Catéteres , Doadores de Óxido NítricoRESUMO
Infection of indwelling catheters is a common healthcare problem, resulting in higher morbidity and mortality. The vulnerable population reliant on catheters post-surgery for food and fluid intake, blood transfusion, or urinary incontinence or retention is susceptible to hospital-acquired infection originating from the very catheter. Bacterial adhesion on catheters can take place during the insertion or over time when catheters are used for an extended period. Nitric oxide-releasing materials have shown promise in exhibiting antibacterial properties without the risk of antibacterial resistance which can be an issue with conventional antibiotics. In this study, 1, 5, and 10 wt % selenium (Se) and 10 wt % S-nitrosoglutathione (GSNO)-incorporated catheters were prepared through a layer-by-layer dip-coating method to demonstrate NO-releasing and NO-generating capability of the catheters. The presence of Se on the catheter interface resulted in a 5 times higher NO flux in 10% Se-GSNO catheter through catalytic NO generation. A physiological level of NO release was observed from 10% Se-GSNO catheters for 5 d, along with an enhanced NO generation via the catalytic activity as Se was able to increase NO availability. The catheters were also found to be compatible and stable when subjected to sterilization and storage, even at room temperature. Additionally, the catheters showed a 97.02% and 93.24% reduction in the adhesion of clinically relevant strains of Escherichia coli and Staphylococcus aureus, respectively. Cytocompatibility testing of the catheter with 3T3 mouse fibroblast cells supports the material's biocompatibility. These findings from the study establish the proposed catheter as a prospective antibacterial material that can be translated into a clinical setting to combat catheter-related infections.
Assuntos
Anti-Infecciosos , Biomimética , Camundongos , Animais , Estudos Prospectivos , Catéteres , Antibacterianos/farmacologia , Escherichia coliRESUMO
Light-controlled therapies offer a promising strategy to prevent and suppress infections caused by numerous bacterial pathogens. Excitation of exogenously supplied photosensitizers (PS) at specific wavelengths elicits levels of reactive oxygen intermediates toxic to bacteria. Porphyrin-based supramolecular nanostructure frameworks (SNF) are effective PS with unique physicochemical properties that have led to their widespread use in photomedicine. Herein, we developed a nitric oxide (NO) releasing, biocompatible, and stable porphyrin-based SNF (SNF-NO), which was achieved through a confined noncovalent self-assembly process based on π-π stacking. Characterization of the SNFs via scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis showed the formation of three-dimensional, well-defined octahedral structures. These SNF-NO were shown to exhibit a red shift due to the noncovalent self-assembly of porphyrins, which also show extended light absorption to broadly cover the entire visible light spectrum to enhance photodynamic therapy (PDT). Under visible light irradiation (46 J cm-2), the SNF generates high yields of singlet oxygen (1O2) radicals, hydroxyl radicals (HO), superoxide radicals (O2), and peroxynitrite (ONOO-) radicals that have shown potential to enhance antimicrobial photodynamic therapy (APDT) against Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative Escherichia coli (E. coli). The resulting SNFs also exhibit significant biofilm dispersion and a decrease in biomass production. The combination of robust photosensitizer SNFs with nitric oxide-releasing capabilities is dynamic in its ability to target pathogenic infections while remaining nontoxic to mammalian cells. The engineered SNFs have enormous potential for treating and managing microbial infections.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Fotoquimioterapia , Porfirinas , Animais , Óxido Nítrico , Escherichia coli , Antibacterianos/farmacologia , Antibacterianos/química , Luz , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Porfirinas/farmacologia , Porfirinas/química , MamíferosRESUMO
Graphene oxide (GO) nanosheets are a promising class of carbon-based materials suitable for application in the construction of medical devices. These materials have inherent antimicrobial properties based on sheet size, but these effects must be carefully traded off to maintain biocompatibility. Chemical modification of functional groups to the lattice structure of GO nanosheets enables unique opportunities to introduce new surface properties to bolster biological effects. Herein, we have developed nitric oxide (NO)-releasing GO nanosheets via immobilization of S-nitrosothiol (RSNO) moieties to GO nanosheets (GO-[NH]x -SNO). These novel RSNO-based GO nanosheets were characterized for chemical functionality via Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, and colorimetric assays for functional group quantification. Stoichiometric control of the available RSNO groups functionalized onto the nanosheets was studied using chemiluminescence-based NO detection methods, showing highly tunable NO release kinetics. Studies of electrical stimulation and subsequent electrochemical reduction of the nanosheets demonstrated further tunability of the NO release based on stimuli. Finally, nanosheets were evaluated for cytotoxicity and antibacterial effects, showing strong cytocompatibility with human fibroblasts in parallel to broad antibacterial and anti-biofilm effects against both Gram-positive and Gram-negative strains. In summary, derivatized GO-(NH)x -SNO nanosheets were shown to have tunable NO release properties, enabling application-specific tailoring for diverse biomedical applications such as antimicrobial coatings and composite fillers for stents, sensors, and other medical devices.
Assuntos
Materiais Biocompatíveis , Grafite , Humanos , Óxido Nítrico , Grafite/química , Antibacterianos/químicaRESUMO
Implant-associated infections arising from biofilm development are known to have detrimental effects with compromised quality of life for the patients, implying a progressing issue in healthcare. It has been a struggle for more than 50 years for the biomaterials field to achieve long-term success of medical implants by discouraging bacterial and protein adhesion without adversely affecting the surrounding tissue and cell functions. However, the rate of infections associated with medical devices is continuously escalating because of the intricate nature of bacterial biofilms, antibiotic resistance, and the lack of ability of monofunctional antibacterial materials to prevent the colonization of bacteria on the device surface. For this reason, many current strategies are focused on the development of novel antibacterial surfaces with dual antimicrobial functionality. These surfaces are based on the combination of two components into one system that can eradicate attached bacteria (antibiotics, peptides, nitric oxide, ammonium salts, light, etc.) and also resist or release adhesion of bacteria (hydrophilic polymers, zwitterionic, antiadhesive, topography, bioinspired surfaces, etc.). This review aims to outline the progress made in the field of biomedical engineering and biomaterials for the development of multifunctional antibacterial biomedical devices. Additionally, principles for material design and fabrication are highlighted using characteristic examples, with a special focus on combinational nitric oxide-releasing biomedical interfaces. A brief perspective on future research directions for engineering of dual-function antibacterial surfaces is also presented.
RESUMO
A large fraction of nosocomial infections is associated with medical devices that are deemed life-threatening in immunocompromised patients. Medical device-related infections are a result of bacterial colonization and biofilm formation on the device surface that affects >1 million people annually in the US alone. Over the past few years, light-based antimicrobial therapy has made substantial advances in tackling microbial colonization. Taking the advantage of light and antibacterial properties of nitric oxide (NO), for the first time, a robust, biocompatible, anti-infective approach to design a universal disposable catheter disinfection insert (DCDI) that can both prevent bacterial adhesion and disinfect indwelling catheters in situ is reported. The DCDI is engineered using a photo-initiated NO donor molecule, incorporated in polymer tubing that is mounted on a side glow fiber optic connected to an LED light source. Using a smartphone application, the NO release from DCDI is photoactivated via white light resulting in tunable physiological levels of NO for up to 24 h. When challenged with microorganisms S. aureus and E. coli, the NO-releasing DCDI statistically reduced microbial attachment by >99% versus the controls with just 4 h of exposure. The DCDI also eradicated â¼97% of pre-colonized bacteria on the CVC catheter model demonstrating the ability to exterminate an established catheter infection. The smart, mobile-operated novel universal antibacterial device can be used to both prevent catheter infections or can be inserted within an infected catheter to eradicate the bacteria without complex surgical interventions. The therapeutic levels of NO generated via illuminating fiber optics can be the next-generation biocompatible solution for catheter-related bloodstream infections.
Assuntos
Anti-Infecciosos , Infecções Relacionadas a Cateter , Antibacterianos/farmacologia , Biofilmes , Infecções Relacionadas a Cateter/microbiologia , Infecções Relacionadas a Cateter/prevenção & controle , Escherichia coli , Humanos , Óxido Nítrico , Polímeros , Smartphone , Staphylococcus aureus/fisiologiaRESUMO
Bacterial infections are a hurdle to the application of medical devices, and in the United States alone, more than one million infection cases are reported annually from indwelling medical devices. Infections not only affect the function of medical devices but also risk the lives and health of patients. Nitric oxide (NO) has been used as an antibacterial therapy that kills bacteria without causing resistance and provides many therapeutic effects such as anti-inflammation, antithrombosis, and angiogenesis. Silicone oils have been widely utilized in manufacturing consumer goods, healthcare products, and medical products. Specifically, liquid silicone oils are used as a medical lubricant that creates lubricated interfaces between medical devices and the exterior physiological environment to improve the performance of medical devices. Herein, we report the first primary S-nitrosothiol-based NO-releasing silicone oil (RSNO-Si) that exhibits proactive antibacterial effects. S-nitrosothiol silicone oils (RSNO-Si) were synthesized and the NO payloads ranged from 34.0 to 603.9 µM. The increased NO payload induced higher-viscosity RSNO-Si oils, as RSNO0.1-Si, RSNO0.5-Si, and RSNO1-Si had viscosities of 12.8 ± 0.1 cP, 32.0 ± 0.2 cP, and 35.1 ± 0.3 cP, respectively. RSNO-Si-SR interfaces were fabricated by infusing silicone rubber (SR) in RSNO-Si oil, and the resulting RSNO-Si-SR disks demonstrated NO release without NO donor leaching. RSNO0.1-Si-SR, RSNO0.5-Si-SR, and RSNO1-Si-SR exhibited maximum NO flux at 0.8, 6.5, and 21.5 × 10 -10 mol cm-2 min-1 in 24 h, respectively. RSNO-Si-SR disks also demonstrated 97.45, 95.40, and 96.08% of inhibition against S. aureus in a 4 h bacterial adhesion assay. Considering the easy synthesis, simple fabrication of non-leaching NO-releasing interfaces, tunable payloads, NO flux levels, and antimicrobial effects, RSNO-Si oils exhibited their potential use as platform chemicals for creating antimicrobial medical device surfaces and other antibacterial materials.
Assuntos
Óxido Nítrico , S-Nitrosotióis , Antibacterianos/farmacologia , Humanos , Óxido Nítrico/farmacologia , Óleos/farmacologia , S-Nitrosotióis/farmacologia , Elastômeros de Silicone/farmacologia , Óleos de Silicone/farmacologia , Staphylococcus aureusRESUMO
Physical incorporation of nitric oxide (NO) releasing materials in biomedical grade polymer matrices to fabricate antimicrobial coatings and devices is an economically viable process. However, achieving long-term NO release with a minimum or no leaching of the NO donor from the polymer matrix is still a challenging task. Herein, (N-acetyl-S-nitrosopenicillaminyl)-S-nitrosopenicillamine (SNAP-SNAP), a penicillamine dipeptide NO-releasing molecule, is incorporated into a commercially available biomedical grade silicone rubber (SR) to fabricate a NO-releasing coating (SNAP-SNAP/SR). The storage stabilities of the SNAP-SNAP powder and SNAP-SNAP/SR coating were analyzed at different temperatures. The SNAP-SNAP/SR coatings with varying wt % of SNAP-SNAP showed a tunable and sustained NO release for up to 6 weeks. Further, S-nitroso-N-acetylpenicillamine (SNAP), a well-explored NO-releasing molecule, was incorporated into a biomedical grade silicone polymer to fabricate a NO-releasing coating (SNAP/SR) and a comparative analysis of the NO release and S-nitrosothiol (RSNO) leaching behavior of 10 wt % SNAP-SNAP/SR and 10 wt % SNAP/SR was studied. Interestingly, the 10 wt % SNAP-SNAP/SR coatings exhibited â¼36% higher NO release and 4 times less leaching of NO donors than the 10 wt % SNAP/SR coatings. Further, the 10 wt % SNAP-SNAP/SR coatings exhibited promising antibacterial properties against Staphylococcus aureus and Escherichia coli due to the persistent release of NO. The 10 wt % SNAP-SNAP/SR coatings were also found to be biocompatible against NIH 3T3 mouse fibroblast cells. These results corroborate the sustained stability and NO-releasing properties of the SNAP-SNAP in a silicone polymer matrix and demonstrate the potential for the SNAP-SNAP/SR polymer in the fabrication of long-term indwelling biomedical devices and implants to enhance biocompatibility and resist device-related infections.
Assuntos
Óxido Nítrico , Elastômeros de Silicone , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Escherichia coli/metabolismo , Camundongos , Óxido Nítrico/química , Doadores de Óxido Nítrico/química , Compostos Nitrosos , Polímeros/química , S-Nitroso-N-Acetilpenicilamina/química , S-Nitroso-N-Acetilpenicilamina/farmacologiaRESUMO
Demineralization and breakdown of tooth enamel are characterized by a condition called dental caries or tooth decay, which is caused by two main factors: (1) highly acidic food intake without proper oral hygiene and (2) overactive oral bacteria generating acidic metabolic byproducts. Fluoride treatments have been shown to help rebuild the hydroxyapatite structures that make up 98% of enamel but do not tackle the bacterial overload that continues to threaten future demineralization. Herein, we have created a dual-function Pluronic F127-alginate hydrogel with nitric oxide (NO)- and fluoride-releasing capabilities for the two-pronged treatment of dental caries. Analysis of the hydrogels demonstrated porous, shear-thinning behaviors with tunable mechanical properties. Varying the weight percent of the NO donor S-nitrosoglutathione (GSNO) within the hydrogel enabled physiologically actionable NO release over 4 h, with the fabricated gels demonstrating storage stability over 21 days. This NO-releasing capability resulted in a 97.59% reduction of viable Streptococcus mutans in the planktonic state over 4 h and reduced the preformed biofilm mass by 48.8% after 24 h. Delivery of fluoride ions was confirmed by a fluoride-sensitive electrode, with release levels resulting in the significant prevention of demineralization of hydroxyapatite discs after treatment with an acidic demineralization solution. Exposure to human gingival fibroblasts and human osteoblasts showed cytocompatibility of the hydrogel, demonstrating the potential for the successful treatment of dental caries in patients.
Assuntos
Cárie Dentária , Desmineralização do Dente , Cárie Dentária/tratamento farmacológico , Cárie Dentária/prevenção & controle , Fluoretos/farmacologia , Humanos , Hidrogéis/farmacologia , Hidroxiapatitas , Óxido Nítrico , Streptococcus mutans/fisiologia , Desmineralização do Dente/prevenção & controleRESUMO
Therapeutic agents can be linked to nanoparticles to fortify their selectivity and targeted delivery while impeding systemic toxicity and efficacy loss. Titanium dioxide nanoparticles (TiNPs) owe their rise in biomedical sciences to their versatile applicability, although the lack of inherent antibacterial properties limits its application and necessitates the addition of bactericidal agents along with TiNPs. Structural modifications can improve TiNP's antibacterial impact. The antibacterial efficacy of nitric oxide (NO) against a broad spectrum of bacterial strains is well established. For the first time, S-nitroso-N-acetylpenicillamine (SNAP), an NO donor molecule, was covalently immobilized on TiNPs to form the NO-releasing TiNP-SNAP nanoparticles. The TiNPs were silanized with 3-aminopropyl triethoxysilane, and N-acetyl-d-penicillamine was grafted to them via an amide bond. The nitrosation was carried out by t-butyl nitrite to conjugate the NO-rich SNAP moiety to the surface. The total NO immobilization was measured to be 127.55 ± 4.68 nmol mg-1 using the gold standard chemiluminescence NO analyzer. The NO payload can be released from the TiNP-SNAP under physiological conditions for up to 20 h. The TiNP-SNAP exhibited a concentration-dependent antimicrobial efficiency. At 5 mg mL-1, more than 99.99 and 99.70% reduction in viable Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria, respectively, were observed. No significant cytotoxicity was observed against 3T3 mouse fibroblast cells at all the test concentrations determined by the CCK-8 assay. TiNP-SNAP is a promising and versatile nanoparticle that can significantly impact the usage of TiNPs in a wide variety of applications, such as biomaterial coatings, tissue engineering scaffolds, or wound dressings.
Assuntos
Nanopartículas , Óxido Nítrico , Animais , Antibacterianos/farmacologia , Escherichia coli , Camundongos , Óxido Nítrico/química , Penicilamina/farmacologia , S-Nitroso-N-Acetilpenicilamina/farmacologia , TitânioRESUMO
The presence of bacteria and biofilm on medical device surfaces has been linked to serious infections, increased health care costs, and failure of medical devices. Therefore, antimicrobial biointerfaces and medical devices that can thwart microbial attachment and biofilm formation are urgently needed. Both nitric oxide (NO) and chlorhexidine diacetate (CHXD) possess broad-spectrum antibacterial properties. In the past, individual polymer release systems of CHXD and NO donor S-nitroso-N-acetylpenicillamine (SNAP) incorporated polymer platforms have attracted considerable attention for biomedical/therapeutic applications. However, the combination of the two surfaces has not yet been explored. Herein, the synergy of NO and CHXD was evaluated to create an antimicrobial medical-grade silicone rubber. The 10 wt% SNAP films were fabricated using solvent casting with a topcoat of CHXD (1, 3, and 5 wt%) to generate a dual-active antibacterial interface. Chemiluminescence studies confirmed the NO release from SNAP-CHXD films at physiologically relevant levels (0.5-4 × 10-10 mol min-1 cm-2 ) for at least 3 weeks and CHXD release for at least 7 days. Further characterization of the films via SEM-EDS confirmed uniform distribution of SNAP and presence of CHXD within the polymer films without substantial morphological changes, as confirmed by contact angle hysteresis. Moreover, the dual-active SNAP-CHXD films were able to significantly reduce Escherichia coli and Staphylococcus aureus bacteria (>3-log reduction) compared to controls with no explicit toxicity towards mouse fibroblast cells. The synergy between the two potent antimicrobial agents will help combat bacterial contamination on biointerfaces and enhance the longevity of medical devices.