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Patients who undergo laparotomy for major trauma are amongst the most critically unwell patients, and they have high morbidity and mortality rates. Despite 20 yr of improvements in resuscitation practices, those who present with hypotension continue to have mortality rates of up to 50%. Currently there is no mechanism for capturing national audit data on these patients, leading to their exclusion from potential quality improvement initiatives. We argue that there is an unmet need for quality assurance in this patient cohort and outline possible mechanisms to address this.
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Hipotensión , Laparotomía , Humanos , Auditoría Médica , Mejoramiento de la Calidad , Reino Unido , Estudios RetrospectivosRESUMEN
BACKGROUND: Current predictive machine learning techniques for spontaneous preterm birth heavily rely on a history of previous preterm birth and/or costly techniques such as fetal fibronectin and ultrasound measurement of cervical length to the disadvantage of those considered at low risk and/or those who have no access to more expensive screening tools. AIMS AND OBJECTIVES: We aimed to develop a predictive model for spontaneous preterm delivery < 37 weeks using socio-demographic and clinical data readily available at booking -an approach which could be suitable for all women regardless of their previous obstetric history. METHODS: We developed a logistic regression model using seven feature variables derived from maternal socio-demographic and obstetric history from a preterm birth (n = 917) and a matched full-term (n = 100) cohort in 2018 and 2020 at a tertiary obstetric unit in the UK. A three-fold cross-validation technique was applied with subsets for data training and testing in Python® (version 3.8) using the most predictive factors. The model performance was then compared to the previously published predictive algorithms. RESULTS: The retrospective model showed good predictive accuracy with an AUC of 0.76 (95% CI: 0.71-0.83) for spontaneous preterm birth, with a sensitivity and specificity of 0.71 (95% CI: 0.66-0.76) and 0.78 (95% CI: 0.63-0.88) respectively based on seven variables: maternal age, BMI, ethnicity, smoking, gestational type, substance misuse and parity/obstetric history. CONCLUSION: Pending further validation, our observations suggest that key maternal demographic features, incorporated into a traditional mathematical model, have promising predictive utility for spontaneous preterm birth in pregnant women in our region without the need for cervical length and/or fetal fibronectin.
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Nacimiento Prematuro , Humanos , Femenino , Embarazo , Nacimiento Prematuro/epidemiología , Adulto , Modelos Logísticos , Estudios Retrospectivos , Factores de Riesgo , Aprendizaje Automático , Reino Unido/epidemiología , Valor Predictivo de las Pruebas , Sensibilidad y EspecificidadRESUMEN
Cerium and its derivatives have been used as remedies for wounds since the early 20th century. Cerium nitrate has attracted most attention in the treatment of deep burns, followed later by reports of its antimicrobial properties. Its ability to mimic and replace calcium is presumed to be a major mechanism of its beneficial action. However, despite some encouraging results, the overall data are somewhat confusing with seemingly the same compounds yielding opposing results. Despite this, cerium nitrate is currently used in wound treatment in combination with silver sulfadiazine as Flammacérium. Cerium oxide, especially in nanoparticle form (Nanoceria), has lately captured much interest due to its antibacterial properties mediated via oxidative stress, leading to an increase of published reports. The properties of Nanoceria depend on the synthesis method, their shape and size. Recently, the green synthesis route has gained a lot of interest as an alternative environmentally friendly method, resulting in production of effective antimicrobial and antifungal nanoparticles. Unfortunately, as is the case with antibiotics, emerging bacterial resistance against cerium-derived nanoparticles is a growing concern, especially in the case of bacterial biofilm. However, diverse strategies resulting from better understanding of the biology of cerium are promising. The aim of this paper is to present the progress to date in the use of cerium compounds as antimicrobials in clinical applications (in particular wound healing) and to provide an overview of the mechanisms of action of cerium at both the cellular and molecular level.
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Antiinfecciosos Locales , Infecciones Bacterianas , Quemaduras , Cerio , Nanopartículas , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Infecciones Bacterianas/tratamiento farmacológico , Quemaduras/tratamiento farmacológico , Cerio/farmacología , Cerio/uso terapéutico , Humanos , Cicatrización de HeridasRESUMEN
2-deoxy-D-Ribose (2dDR) was first identified in 1930 in the structure of DNA and discovered as a degradation product of it later when the enzyme thymidine phosphorylase breaks down thymidine into thymine. In 2017, our research group explored the development of wound dressings based on the delivery of this sugar to induce angiogenesis in chronic wounds. In this review, we will survey the small volume of conflicting literature on this and related sugars, some of which are reported to be anti-angiogenic. We review the evidence of 2dDR having the ability to stimulate a range of pro-angiogenic activities in vitro and in a chick pro-angiogenic bioassay and to stimulate new blood vessel formation and wound healing in normal and diabetic rat models. The biological actions of 2dDR were found to be 80 to 100% as effective as VEGF in addition to upregulating the production of VEGF. We then demonstrated the uptake and delivery of the sugar from a range of experimental and commercial dressings. In conclusion, its pro-angiogenic properties combined with its improved stability on storage compared to VEGF, its low cost, and ease of incorporation into a range of established wound dressings make 2dDR an attractive alternative to VEGF for wound dressing development.
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Desoxirribosa/farmacología , Factores de Crecimiento Endotelial Vascular/metabolismo , Cicatrización de Heridas/efectos de los fármacos , Inductores de la Angiogénesis/química , Animales , Vendajes/tendencias , Fenómenos Fisiológicos Cardiovasculares/efectos de los fármacos , Desoxirribosa/metabolismo , Humanos , Morfogénesis/efectos de los fármacos , Neovascularización Fisiológica/efectos de los fármacos , Neovascularización Fisiológica/fisiología , Ribosa/metabolismo , Ribosa/farmacología , Factores de Crecimiento Endotelial Vascular/efectos de los fármacosRESUMEN
PURPOSE OF REVIEW: Major trauma remains one of the leading causes of death worldwide with traumatic brain injury and uncontrolled traumatic bleeding as the main determinants of fatal outcome. Interestingly, the therapeutic approach to trauma-associated bleeding and coagulopathy shows differences between geographic regions, that are reflected in different guidelines and protocols. RECENT FINDINGS: This article summarizes main principles in coagulation diagnostics and compares different strategies for treatment of massive hemorrhage after trauma in different regions of the world. How would a bleeding trauma patient be managed if they got hit by the bus in the United States, United Kingdom, Germany, Switzerland, Austria, Denmark, Australia, or in Japan? SUMMARY: There are multiple coexistent treatment standards for trauma-induced coagulopathy in different countries and different trauma centers. Most of them initially follow a protocol-based approach and subsequently focus on predefined clinical and laboratory targets.
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Trastornos de la Coagulación Sanguínea , Heridas y Lesiones , Australia , Trastornos de la Coagulación Sanguínea/etiología , Trastornos de la Coagulación Sanguínea/terapia , Alemania , Objetivos , Hemorragia/etiología , Hemorragia/terapia , Humanos , Japón , Reino UnidoRESUMEN
[This corrects the article DOI: 10.1371/journal.pmed.1002352.].
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OBJECTIVE: To evaluate (1) levels of the host-defense/antimicrobial peptide LL-37 in patients with trauma and hemorrhagic shock (HS) and (2) the effects of a synthetic host-defense peptide; Pep19-4LF on multiple organ failure (MOF) associated with HS. BACKGROUND: HS is a common cause of death in severely injured patients. There is no specific therapy that reduces HS-associated MOF. METHODS: (1) LL-37 was measured in 47 trauma/HS patients admitted to an urban major trauma center. (2) Male Wistar rats were submitted to HS (90âmin, target mean arterial pressure: 27-32âmm Hg) or sham operation. Rats were treated with Pep19-4LF [66 (n = 8) or 333âµg/kgâ·âh (n = 8)] or vehicle (n = 12) for 4 hours following resuscitation. RESULTS: Plasma LL-37 was 12-fold higher in patients with trauma/HS compared to healthy volunteers. HS rats treated with Pep19-4LF (high dose) had a higher mean arterial pressure at the end of the 4-hour resuscitation period (79â±â4 vs 54â±â5âmm Hg) and less renal dysfunction, liver injury, and lung inflammation than HS rats treated with vehicle. Pep19-4LF enhanced (kidney/liver) the phosphorylation of (1) protein kinase B and (2) endothelial nitric oxide synthase. Pep19-4LF attenuated the HS-induced (1) translocation of p65 from cytosol to nucleus, (2) phosphorylation of IκB kinase on Ser, and (3) phosphorylation of IκBα on Ser resulting in inhibition of nuclear factor kappa B and formation of proinflammatory cytokines. Pep19-4LF prevented the release of tumor necrosis factor alpha caused by heparan sulfate in human mononuclear cells by binding to this damage-associated molecular pattern. CONCLUSIONS: Trauma-associated HS results in release of LL-37. The synthetic host-defense/antimicrobial peptide Pep19-4LF attenuates the organ injury/dysfunction associated with HS.
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Antiinfecciosos/uso terapéutico , Péptidos Catiónicos Antimicrobianos/sangre , Insuficiencia Multiorgánica/prevención & control , Péptidos/uso terapéutico , Sustancias Protectoras/uso terapéutico , Choque Hemorrágico/tratamiento farmacológico , Heridas y Lesiones/complicaciones , Animales , Biomarcadores/sangre , Estudios de Casos y Controles , Terapia Combinada , Humanos , Masculino , Insuficiencia Multiorgánica/etiología , Ratas , Ratas Wistar , Resucitación , Choque Hemorrágico/sangre , Choque Hemorrágico/complicaciones , Choque Hemorrágico/diagnóstico , Resultado del Tratamiento , CatelicidinasRESUMEN
BACKGROUND: Severe trauma induces a widespread response of the immune system. This "genomic storm" can lead to poor outcomes, including Multiple Organ Dysfunction Syndrome (MODS). MODS carries a high mortality and morbidity rate and adversely affects long-term health outcomes. Contemporary management of MODS is entirely supportive, and no specific therapeutics have been shown to be effective in reducing incidence or severity. The pathogenesis of MODS remains unclear, and several models are proposed, such as excessive inflammation, a second-hit insult, or an imbalance between pro- and anti-inflammatory pathways. We postulated that the hyperacute window after trauma may hold the key to understanding how the genomic storm is initiated and may lead to a new understanding of the pathogenesis of MODS. METHODS AND FINDINGS: We performed whole blood transcriptome and flow cytometry analyses on a total of 70 critically injured patients (Injury Severity Score [ISS] ≥ 25) at The Royal London Hospital in the hyperacute time period within 2 hours of injury. We compared transcriptome findings in 36 critically injured patients with those of 6 patients with minor injuries (ISS ≤ 4). We then performed flow cytometry analyses in 34 critically injured patients and compared findings with those of 9 healthy volunteers. Immediately after injury, only 1,239 gene transcripts (4%) were differentially expressed in critically injured patients. By 24 hours after injury, 6,294 transcripts (21%) were differentially expressed compared to the hyperacute window. Only 202 (16%) genes differentially expressed in the hyperacute window were still expressed in the same direction at 24 hours postinjury. Pathway analysis showed principally up-regulation of pattern recognition and innate inflammatory pathways, with down-regulation of adaptive responses. Immune deconvolution, flow cytometry, and modular analysis suggested a central role for neutrophils and Natural Killer (NK) cells, with underexpression of T- and B cell responses. In the transcriptome cohort, 20 critically injured patients later developed MODS. Compared with the 16 patients who did not develop MODS (NoMODS), maximal differential expression was seen within the hyperacute window. In MODS versus NoMODS, 363 genes were differentially expressed on admission, compared to only 33 at 24 hours postinjury. MODS transcripts differentially expressed in the hyperacute window showed enrichment among diseases and biological functions associated with cell survival and organismal death rather than inflammatory pathways. There was differential up-regulation of NK cell signalling pathways and markers in patients who would later develop MODS, with down-regulation of neutrophil deconvolution markers. This study is limited by its sample size, precluding more detailed analyses of drivers of the hyperacute response and different MODS phenotypes, and requires validation in other critically injured cohorts. CONCLUSIONS: In this study, we showed how the hyperacute postinjury time window contained a focused, specific signature of the response to critical injury that led to widespread genomic activation. A transcriptomic signature for later development of MODS was present in this hyperacute window; it showed a strong signal for cell death and survival pathways and implicated NK cells and neutrophil populations in this differential response.
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Inflamación/inmunología , Insuficiencia Multiorgánica/diagnóstico , Insuficiencia Multiorgánica/etiología , Insuficiencia Multiorgánica/terapia , Heridas y Lesiones/complicaciones , Heridas y Lesiones/terapia , Enfermedad Aguda , Adulto , Análisis Químico de la Sangre , Femenino , Citometría de Flujo , Humanos , Inflamación/sangre , Inflamación/etiología , Inflamación/terapia , Londres , Masculino , Persona de Mediana Edad , Insuficiencia Multiorgánica/inmunología , Estudios Prospectivos , Factores de Tiempo , Transcriptoma , Heridas y Lesiones/sangre , Heridas y Lesiones/inmunologíaRESUMEN
The behavior of a linear copolymer of N-isopropylacrylamide with pendant vancomycin functionality was compared to an analogous highly branched copolymer with vancomycin functionality at the chain ends. Highly branched poly(N-isopropylacrylamide) modified with vancomycin (HB-PNIPAM-van) was synthesized by functionalization of the HB-PNIPAM, prepared using reversible addition-fragmentation chain transfer polymerization. Linear PNIPAM with pendant vancomycin functionality (L-PNIPAM-van) was synthesized by functionalization of poly(N-isopropylacrylamide-co-vinyl benzoic acid). HB-PNIPAM-van aggregated S. aureus effectively, whereas the L-PNIPAM-van polymer did not. It was found that when the HB-PNIPAM-van was incubated with S. aureus the resultant phase transition provided an increase in the intensity of fluorescence of a solvatochromic dye, nile red, added to the system. In contrast, a significantly lower increase in fluorescence intensity was obtained when L-PNIPAM-van was incubated with S. aureus. These data showed that the degree of desolvation of HB-PNIPAM-van was much greater than the desolvation of the linear version. Using microcalorimetry, it was shown that there were no significant differences in the affinities of the polymer ligands for d-Ala-d-Ala and therefore differences in the interactions with bacteria were associated with changes in the probability of access of the polymer bound ligands to the d-Ala-d-Ala dipeptide. The data support the hypothesis that generation of polymer systems that respond to cellular targets, for applications such as cell targeting, detection of pathogens etc., requires the use of branched polymers with ligands situated at the chain ends.
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Acrilamidas/química , Antibacterianos/química , Staphylococcus aureus/efectos de los fármacos , Vancomicina/química , Acrilamidas/farmacología , Antibacterianos/farmacología , Relación Estructura-Actividad , Vancomicina/farmacologíaRESUMEN
Biologic drugs represent an important new category of drugs in the effort to improve health outcomes in this country. Yet, these cutting-edge drugs are often cost prohibitive, preventing access for many Americans. Recognizing the need for more affordable, generic substitutes for biologic drugsor biosimilarsCongress recently created a biosimilars approval pathway that would enable these cheaper biologic drugs to obtain FDA approval and reach patients more quickly. Unfortunately, original biologics manufacturers have sought to extend their current monopoly profits by erecting various legal and regulatory barriers to entry. Their legal maneuvers take many forms, from delaying approval of safe biosimilars to abrogating previous commitments to international drug-naming protocols, and even circumventing Congressional intent for biosimilar substitution. Regrettably, these policies reduce competition in the market for biologic drugs, impede drug innovation, increase drug costs, and limit patient access to these important medications. This article explores the conflict between biologics and biosimilars, and the consequences that barriers to biosimilar entry in this market will create.
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Productos Biológicos , Biosimilares Farmacéuticos , Aprobación de Drogas , Costos de los Medicamentos , Competencia Económica , Accesibilidad a los Servicios de Salud , Humanos , Maniobras Políticas , Estados Unidos , United States Food and Drug AdministrationRESUMEN
Prescription painkiller abuse is the fastest growing drug problem in the United States. In the past year, approximately one out of twenty Americans reported misuse or abuse of prescription painkillers. Several factors contribute to the prescription painkiller epidemic. Drug abusers use various methods--such as doctor shopping, paying with cash, and filling prescriptions in different states--to avoid detection and obtain prescription painkillers for illegitimate uses. A few rogue physicians and pharmacists, lured by substantial profits, enable drug abusers by illegally prescribing or supplying controlled substances. Even ethical physicians rarely have adequate training to recognize and address prescription drug abuse, and as a result, prescribe painkillers to patients who are not using them for legitimate medical purposes. Similarly, although the majority of pharmacies have taken steps to combat drug abuse and reduce prescription painkiller dispensing, under current reporting systems, pharmacists lack visibility into several important indicators of drug abuse. As a result, even the most vigilant pharmacists find it extremely difficult to identify and detect drug abuse with certainty. While state governments have established prescription drug monitoring programs (PDMPs) to crack down on prescription drug abuse, these programs have proven to be inadequate. The programs currently suffer from inadequate data collection, ineffective utilization of data, insufficient interstate data sharing, and constraints on sharing data with law enforcement and state agencies. By contrast, third-party prescription payment systems run by pharmacy benefit managers (PBMs) or health insurers have been effective in detecting prescription drug abuse. This paper suggests that a national prescription drug reporting program building on existing PBM networks could be significantly more effective than existing state PDMPs in detecting prescription drug abuse.
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Analgésicos Opioides/efectos adversos , Control de Medicamentos y Narcóticos/organización & administración , Mal Uso de Medicamentos de Venta con Receta/prevención & control , Control de Medicamentos y Narcóticos/legislación & jurisprudencia , Humanos , Farmacéuticos/legislación & jurisprudencia , Mal Uso de Medicamentos de Venta con Receta/legislación & jurisprudencia , Gobierno Estatal , Estados UnidosRESUMEN
OBJECTIVE: To study the feasibility of using poly methyl methacrylate (PMMA) filament and fused deposition modeling (FDM) to manufacture denture bases via the development of a study that considers both conventional and additive-based manufacturing techniques. MATERIALS AND METHODS: Five sample groups were compared: heat and cold cured acrylic resins, CAD/CAM milled PMMA, 3D-printed PMMA (via FDM), and 3D-printed methacrylate resin (via stereolithography, SLA). All groups were subjected to mechanical testing (flexural strength, impact strength, and hardness), water sorption and solubility tests, a tooth bonding test, microbiological assessment, and accuracy of fit measurements. The performance of sample groups was referred to ISO 20795-1 and ISO/TS 19736. The data was analyzed using one-way ANOVA. RESULTS: Samples manufactured using FDM performed within ISO specifications for mechanical testing, water sorption, and solubility tests. However, the FDM group failed to achieve the ISO requirements for the tooth bonding test. FDM samples presented a rough surface finish which could ultimately encourage an undesirable high level of microbial adhesion. For accuracy of fit, FDM samples showed a lower degree of accuracy than existing materials. CONCLUSIONS: Although FDM samples were a cost-effective option and were able to be quickly manufactured in a reproducible manner, the results demonstrated that current recommended testing regimes for conventionally manufactured denture-based polymers are not directly applicable to additive-manufactured denture base polymers. Therefore, new standards should be developed to ensure the correct implementation of additive manufacturing techniques within denture-based fabrication workflow.
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Resinas Acrílicas , Diseño Asistido por Computadora , Bases para Dentadura , Ensayo de Materiales , Polimetil Metacrilato , Impresión Tridimensional , Bases para Dentadura/microbiología , Polimetil Metacrilato/química , Resinas Acrílicas/química , Diseño de Dentadura , Humanos , Estudios de Factibilidad , Materiales Dentales/química , Recubrimiento Dental Adhesivo/métodos , Propiedades de Superficie , Estereolitografía , Resistencia Flexional , Dureza , SolubilidadRESUMEN
Enterococci are robust Gram-positive bacteria that pose a significant threat in healthcare settings due to antibiotic resistance, with vancomycin-resistant enterococci (VRE) most prominent. To tackle this issue, bacteriophages (bacterial viruses) can be exploited as they specifically and efficiently target bacteria. Here, we successfully isolated and characterised a set of novel phages: SHEF10, SHEF11, SHEF13, SHEF14, and SHEF16 which target E. faecalis (SHEF10,11,13), or E. faecium (SHEF13, SHEF14 & SHEF16) strains including a range of clinical and VRE isolates. Genomic analysis shows that all phages are strictly lytic and diverse in terms of genome size and content, quickly and effectively lysing strains at different multiplicity of infections. Detailed analysis of the broad host-range SHEF13 phage revealed the crucial role of the enterococcal polysaccharide antigen (EPA) variable region in its infection of E. faecalis V583. In parallel, the discovery of a carbohydrate-targeting domain (CBM22) found conserved within the three phage genomes indicates a role in cell surface interactions that may be important in phage-bacterial interactons. These findings advance our comprehension of phage-host interactions and pave the way for targeted therapeutic strategies against antibiotic-resistant enterococcal infections.
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Bacteriófagos , Enterococcus faecalis , Genoma Viral , Especificidad del Huésped , Bacteriófagos/genética , Bacteriófagos/fisiología , Bacteriófagos/clasificación , Bacteriófagos/aislamiento & purificación , Enterococcus faecalis/virología , Enterococcus faecalis/genética , Enterococcus faecium/virología , Enterococcus faecium/genética , Enterococcus/virología , Enterococcus/genética , Enterococos Resistentes a la Vancomicina/virología , Enterococos Resistentes a la Vancomicina/genética , Infecciones por Bacterias Grampositivas/microbiología , HumanosRESUMEN
PURPOSE: This study aimed at determining whether intravenous artesunate is safe and effective in reducing multiple organ dysfunction syndrome in trauma patients with major hemorrhage. METHODS: TOP-ART, a randomized, blinded, placebo-controlled, phase IIa trial, was conducted at a London major trauma center in adult trauma patients who activated the major hemorrhage protocol. Participants received artesunate or placebo (2:1 randomization ratio) as an intravenous bolus dose (2.4 mg/kg or 4.8 mg/kg) within 4 h of injury. The safety outcome was the 28-day serious adverse event (SAE) rate. The primary efficacy outcome was the 48 h sequential organ failure assessment (SOFA) score. The per-protocol recruitment target was 105 patients. RESULTS: The trial was terminated after enrolment of 90 patients because of safety concerns. Eighty-three participants received artesunate (n = 54) or placebo (n = 29) and formed the safety population and 75 met per-protocol criteria (48 artesunate, 27 placebo). Admission characteristics were similar between groups (overall 88% male, median age 29 years, median injury severity score 22), except participants who received artesunate were more shocked (median base deficit 9 vs. 4.7, p = 0.042). SAEs occurred in 17 artesunate participants (31%) vs. 5 who received placebo (17%). Venous thromboembolic events (VTE) occurred in 9 artesunate participants (17%) vs. 1 who received placebo (3%). Superiority of artesunate was not supported by the 48 h SOFA score (median 5.5 artesunate vs. 4 placebo, p = 0.303) or any of the trial's secondary endpoints. CONCLUSION: Among critically ill trauma patients, artesunate is unlikely to improve organ dysfunction and might be associated with a higher VTE rate.
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COVID-19 , Tromboembolia Venosa , Adulto , Humanos , Masculino , Femenino , COVID-19/epidemiología , SARS-CoV-2 , Artesunato/efectos adversos , Hemorragia/etiología , Resultado del TratamientoRESUMEN
Polymyxin peptide conjugated to the end groups of highly branched poly(N-isopropyl acrylamide) was shown to bind to a Gram negative bacterium, Pseudomonas aeruginosa . The nonbound polymer had a lower critical solution temperature (LCST) above 60 °C. However, binding caused aggregation, which was disrupted on cooling of the bacteria and polymer mixture. The data indicate that polymer binding of bacteria occurred by interaction of the end groups with lipopolysaccharide and that the binding decreased the LCST to below 37 °C. Cooling then progressed the polymer/bacteria aggregate through a bound LCST into an open polymer coil conformation that was not adhesive to P. aeruginosa .
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Acrilamidas , Antibacterianos , Polímeros , Polimixina B , Pseudomonas aeruginosa/crecimiento & desarrollo , Acrilamidas/síntesis química , Acrilamidas/química , Acrilamidas/farmacología , Resinas Acrílicas , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Lipopolisacáridos/química , Lipopolisacáridos/metabolismo , Polímeros/síntesis química , Polímeros/química , Polímeros/farmacología , Polimixina B/química , Polimixina B/farmacología , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/metabolismoRESUMEN
Branched poly(N-isopropylacrylamide) was functionalized with Amphotericin B (AmB) at the chain ends to produce an antifungal material. The polymer showed antifungal properties against AmB-sensitive strains of Candida albicans, Fusarium keratoplasticum and Aspergillus flavus (minimal inhibitory concentration ranged from 5 to 500 µg ml-1) but was not effective against an AmB resistant strain of C. albicans nor against Candida tropicalis. The polymer end groups bound to the AmB target, ergosterol, and the fluorescence spectrum of a dye used as a solvatochromic probe, Nile red, was blue shifted indicating that segments of the polymer became desolvated on binding. The polymer was less toxic to corneal and renal epithelial cells and explanted corneal tissue than the free drug. Also, the polymer did not induce reactive oxygen species release from peripheral blood mononuclear cells, nor did it cause a substantial release of the proinflammatory cytokines, tumour necrosis factor-α and interleukin-1ß (at 0.5 mg ml-1).
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Binding of highly branched poly(N-isopropylacrylamide) with vancomycin end groups to Staphylococcus aureus induced a coil-to-globule phase transition. The polymers aggregated this gram-positive bacteria (but not gram-negative bacteria) over a wide range of temperatures, but cooling to 24-26 degrees C progressed the polymer-bound bacteria through a globule-to-coil phase transition, after which the bacteria were released.
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Acrilamidas/química , Acrilamidas/metabolismo , Bacterias/metabolismo , Polímeros/química , Polímeros/metabolismo , Vancomicina/química , Resinas Acrílicas , Espectrometría de Fluorescencia , TemperaturaRESUMEN
The global challenge of antimicrobial resistance is of increasing concern, and alternatives to currently used antibiotics or methods to improve their stewardship are sought worldwide. Microbial biofilms, complex 3D communities of bacteria and/or fungi, are difficult to treat with antibiotics for several reasons. These include their protective coats of extracellular matrix proteins which are difficult for antibiotics to penetrate. Nanoparticles (NP) are one way to rise to this challenge; whilst they exist in many forms naturally there has been a profusion in synthesis of these small (<100â nm) particles for biomedical applications. Their small size allows them to penetrate the biofilm matrix, and as well as some NP being inherently antimicrobial, they also can be modified by doping with antimicrobial payloads or coated to increase their effectiveness. This mini-review examines the current role of NP in treating wound biofilms and the rise in multifunctionality of NP.
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Antiinfecciosos , Infección de Heridas , Antibacterianos/uso terapéutico , Bacterias , Biopelículas , Humanos , Infección de Heridas/tratamiento farmacológicoRESUMEN
Infectious diseases (exacerbated by antimicrobial resistance) cause death, loss of quality of life and economic burden globally. Materials with inherent antimicrobial properties offer the potential to reduce the spread of infection through transfer via surfaces or solutions, or to directly reduce microbial numbers in a host if used as implants. Additive Manufacturing (AM) techniques offer shorter supply chains, faster delivery, mass customisation and reduced unit costs, as well as highly complicated part geometries which are potentially harder to clean and sterilise. Here, we present a new approach to introducing antibacterial properties into AM, using Laser Sintering, by combining antimicrobial and base polymer powders prior to processing. We demonstrate that the mechanical properties of the resultant composite parts are similar to standard polymer parts and reveal the mode of the antibacterial activity. We show that antibacterial activity is modulated by the presence of obstructing compounds in different experimental media, which will inform appropriate use cases. We show that the material is not toxic to mammalian cells. This material could be quickly used for commercial products, and our approach could be adopted more generally to add new functionality to Laser Sintered parts.
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Antibacterianos/química , Antibacterianos/farmacología , Ensayo de Materiales/métodos , Nylons/química , Plata/química , Células Cultivadas , Liberación de Fármacos , Fibroblastos/efectos de los fármacos , Vidrio , Humanos , Rayos Láser , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Nylons/farmacología , Fosfatos/química , Polvos , Prótesis e Implantes , Pseudomonas aeruginosa/efectos de los fármacos , Plata/farmacocinética , Compuestos de Plata/química , Espectrometría por Rayos X , Staphylococcus aureus/efectos de los fármacos , Resistencia a la Tracción , Microtomografía por Rayos XRESUMEN
The physiological wound healing process involves a cascade of events which could be affected by several factors resulting in chronic, non-healing wounds. The latter represent a great burden especially when bacterial biofilms are formed. The rise in antibiotic resistance amongst infectious microorganisms leads to the need of novel approaches to treat this clinical issue. In this context, the use of advanced biomaterials, which can enhance the physiological expression and secretion of the growth factors involved in the wound healing process, is gaining increasing attention as a robust and appealing alternative approach. Among them, mesoporous glasses are of particular interest due to their excellent textural properties and to the possibility of incorporating and releasing specific therapeutic species, such as metallic ions. One of the most attractive therapeutic ions is copper thanks to its proangiogenic and antibacterial effects. In this contribution, copper containing mesoporous glass nanoparticles were proposed as a multifunctional device to treat chronic wounds. The developed nanoparticles evidenced a very high specific surface area (740 m2/g), uniform pores of 4 nm and an almost total release of the therapeutic ion within 72 h of soaking. The produced nanoparticles were biocompatible and, when tested against Gram positive and Gram negative bacterial species, demonstrated antibacterial activity against both planktonic and biofilm bacteria in 2D cell monolayers, and in a 3D human model of infected skin. Their proangiogenic effect was tested with both the aortic ring and the chick chorioallantoic membrane assays and an increase in endothelial cell outgrowth at a concentration range between 30 and 300 ng/mL was shown. Overall, in this study biocompatible, multifunctional Cu-containing mesoporous glass nanoparticles were successfully produced and demonstrated to exert both antibacterial and proangiogenic effects.