Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Microbiology (Reading) ; 170(3)2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38568202

RESUMEN

Understanding the evolution of antibiotic resistance is important for combating drug-resistant bacteria. In this work, we investigated the adaptive response of Pseudomonas aeruginosa to ciprofloxacin. Ciprofloxacin-susceptible P. aeruginosa ATCC 9027, CIP-E1 (P. aeruginosa ATCC 9027 exposed to ciprofloxacin for 14 days) and CIP-E2 (CIP-E1 cultured in antibiotic-free broth for 10 days) were compared. Phenotypic responses including cell morphology, antibiotic susceptibility, and production of pyoverdine, pyocyanin and rhamnolipid were assessed. Proteomic responses were evaluated using comparative iTRAQ labelling LC-MS/MS to identify differentially expressed proteins (DEPs). Expression of associated genes coding for notable DEPs and their related regulatory genes were checked using quantitative reverse transcriptase PCR. CIP-E1 displayed a heterogeneous morphology, featuring both filamentous cells and cells with reduced length and width. By contrast, although filaments were not present, CIP-E2 still exhibited size reduction. Considering the MIC values, ciprofloxacin-exposed strains developed resistance to fluoroquinolone antibiotics but maintained susceptibility to other antibiotic classes, except for carbapenems. Pyoverdine and pyocyanin production showed insignificant decreases, whereas there was a significant decrease in rhamnolipid production. A total of 1039 proteins were identified, of which approximately 25 % were DEPs. In general, there were more downregulated proteins than upregulated proteins. Noted changes included decreased OprD and PilP, and increased MexEF-OprN, MvaT and Vfr, as well as proteins of ribosome machinery and metabolism clusters. Gene expression analysis confirmed the proteomic data and indicated the downregulation of rpoB and rpoS. In summary, the response to CIP involved approximately a quarter of the proteome, primarily associated with ribosome machinery and metabolic processes. Potential targets for bacterial interference encompassed outer membrane proteins and global regulators, such as MvaT.


Asunto(s)
Ciprofloxacina , Infecciones por Pseudomonas , Humanos , Ciprofloxacina/farmacología , Pseudomonas aeruginosa/genética , Cromatografía Liquida , Proteómica , Piocianina , Espectrometría de Masas en Tándem , Antibacterianos/farmacología
2.
Regen Ther ; 25: 147-156, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38486821

RESUMEN

Introduction: Vitamin D3 plays a vital role in bone health, with low levels of vitamin D3 being related to skeletal fragility, fractures, and metabolic disorders such as diabetes. Metformin is known as an antihyperglycemic agent for regulating blood sugar. A correlation between diabetes mellitus and osteoporosis is attracting considerable interest, and research to find the prevention and treatment is gradually being studied. In this study, we investigated the effect of metformin and vitamin D3 on osteogenic differentiation of human adipose tissue-derived mesenchymal stem cells (AT-MSCs) under high d-glucose concentrations and optimized by combining vitamin D3 and metformin in the process. Methods: ROS production of AT-MSCs under high d-glucose conditions was measured by DCFH-DA assay. The differentiated AT-MSCs were analyzed by Alizarin Red S staining and optical density measurement. The investigation involved the examination of osteogenic master genes' expressions using quantitative reverse transcription polymerase chain reaction (qRT-PCR) techniques. Results: Interestingly, the results have shown that human AT-MSCs will exhibit high ROS accumulation and low osteogenic differentiation capabilities, indicated by low calcium deposition, as well as low expression of indicative genes such as ALP, Runx-2 under high d-glucose conditions. The combination of vitamin D3 and metformin remarkedly accelerated the osteogenic differentiation of AT-MSCs under high d-glucose concentrations more effectively than the administration of either agent. Conclusions: This study partially explains an aspect of an in vitro model for pre-clinical drug screening for osteoporosis-related diabetic pathological mechanisms, which can be applied for further research on the prevention or treatment of osteoporosis in diabetic patients.

3.
Macromol Biosci ; 23(12): e2300156, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37579128

RESUMEN

Dynamic hydrogel systems from N,O-carboxymethyl chitosan (NOCC) are investigated in the past years, which has facilitated their widespread use in many biomedical engineering applications. However, the influence of the polymer's oxidation levels on the hydrogel biological properties is not fully investigated. In this study, chitosan is converted into NOCC and introduced to react spontaneously with oxidized xanthan gum (OXG) to form several injectable hydrogels with controlled degradability. Different oxidation levels of xanthan gum, as well as NOCC/OXG volume ratios, are trialed. The infrared spectroscopy spectra verify chemical modification on OXG and successful crosslinking. With increasing oxidation levels, more dialdehyde groups are introduced into the OXG, resulting in changes in physical properties including gelation, swelling, and self-healing efficiency. Under different volume ratios, the hydrogel shows a stable structure and rigidity with higher mechanical properties, and a slower degradation rate. The shear-thinning and self-healing properties of the hydrogels are confirmed. In vitro assays with L929 cells show the biocompatibility of all formulations although the use of a high amount of OXG15 and OXG25 limited the cell proliferation capacity. Findings in this study suggested a suitable amount of OXG at different oxidation levels in NOCC hydrogel systems for tissue engineering applications.


Asunto(s)
Quitosano , Quitosano/química , Hidrogeles/farmacología , Hidrogeles/química , Polímeros
4.
Int J Biol Macromol ; 243: 125248, 2023 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-37307971

RESUMEN

Dual-drug delivery systems for anticancer therapy have recently attracted substantial attention due to their potency to overcome limitations of conventional anti-cancer drugs, tackle drug resistance problems, as well as improve the therapeutic efficacy. In this study, we introduced a novel nanogel based on folic acid-gelatin-pluronic P123 (FA-GP-P123) conjugate to simultaneously deliver quercetin (QU) and paclitaxel (PTX) to the targeted tumor. The results indicated that the drug loading capacity of FA-GP-P123 nanogels was significantly higher than that of P123 micelles. The kinetic release profiles of QU and PTX from the nanocarriers were governed by Fickian diffusion and swelling behavior, respectively. Notably, FA-GP-P123/QU/PTX dual-drug delivery system induced higher toxicity to MCF-7 and Hela cancer cells than either QU or PTX individual delivery system, and the non-targeted dug delivery system (GP-P123/QU/PTX), indicating the synergistic combination of dual drugs and FA positive targeting effect. Furthermore, FA-GP-P123 could effectively deliver QU and PTX to tumors in vivo after administration into MCF-7 tumor-bearing mice, which resulted in 94.20 ± 5.90 % of tumor volume reduced at day 14. Moreover, the side effects of the dual-drug delivery system were significantly reduced. Overall, we suggest FA-GP-P123 as potential nanocarrier for dual-drug delivery for targeted chemotherapy.


Asunto(s)
Gelatina , Paclitaxel , Ratones , Animales , Paclitaxel/farmacología , Paclitaxel/uso terapéutico , Gelatina/farmacología , Quercetina/farmacología , Nanogeles , Línea Celular Tumoral , Resistencia a Antineoplásicos , Sistemas de Liberación de Medicamentos/métodos , Micelas , Ácido Fólico/farmacología , Portadores de Fármacos/farmacología
5.
Inorg Chem ; 62(26): 10298-10306, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37318756

RESUMEN

The adsorption ability of hydrogen, hydroxide, and oxygenic intermediates plays a crucial role in electrochemical water splitting. Electron-deficient metal-active sites can prompt electrocatalytic activity by improving the adsorption ability of intermediates. However, it remains a significant challenge to synthesize highly abundant and stable electron-deficient metal-active site electrocatalysts. Herein, we present a general approach to synthesizing a hollow ternary metal fluoride (FeCoNiF2) nanoflake array as an efficient and robust bifunctional electrocatalyst for the hydrogen evolution reaction (HER) and urea oxidation reaction (UOR). We find that the F anion withdraws electrons from the metal centers, inducing an electron-deficient metal center catalyst. The rationally designed hollow nanoflake array exhibits the overpotential of 30 mV for HER and 130 mV for UOR at a current density of 10 mA cm-2 and superior stability without decay events over 150 h at a large current density of up to 100 mA cm-2. Remarkably, the assembled urea electrolyzer using a bifunctional hollow FeCoNiF2 nanoflake array catalyst requires cell voltages of only 1.352 and 1.703 V to afford current densities of 10 and 100 mA cm-2, respectively, which are 116 mV less compared with that required for overall water splitting.

6.
Int Health ; 15(4): 365-375, 2023 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-35696091

RESUMEN

BACKGROUND: This study investigated post-traumatic stress disorder (PTSD), anxiety, depression and their related factors among coronavirus disease 2019 (COVID-19) patients during the fourth wave of the pandemic in Vietnam. METHODS: Vietnamese-fluent confirmed COVID-19 patients for at least 3 d were recruited in this online cross-sectional study to answer a three-part questionnaire including participants' sociodemographic characteristics, PTSD (Impact of Event Scale-Revised) and anxiety and depression (Hospital Anxiety and Depression Scale). Associated factors were determined using multivariable binary logistic regression models. RESULTS: Of 1544 responses, the majority were female (53.0%), ages 18-39 y (74.8%) and were isolated and treated at field hospitals (72.2%). Family or friends were the greatest sources of mental support (68.2%), followed by healthcare providers (51.1%). The overall prevalence rates of PTSD, anxiety and depression among COVID-19 patients were 22.9%, 11.2% and 17.4%, respectively. Risk factors included older age, higher education, getting infected from the public, knowing someone who died from COVID-19 and high perception of life threat. Meanwhile, mental assistance from family or friends, a greater number of supporters, living with someone not vulnerable and higher salaries were significantly protective factors. CONCLUSIONS: The psychological responses associated with some sociodemographic details. Family or friends should be the first line of mental interventions for COVID-19 patients.


Asunto(s)
COVID-19 , Trastornos por Estrés Postraumático , Humanos , Femenino , Masculino , COVID-19/epidemiología , Trastornos por Estrés Postraumático/epidemiología , Depresión/epidemiología , Depresión/psicología , Pandemias , Estudios Transversales , Vietnam/epidemiología , SARS-CoV-2 , Ansiedad/epidemiología , Ansiedad/psicología
7.
Phys Chem Chem Phys ; 24(1): 468-476, 2021 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-34901980

RESUMEN

Kesterite Cu2ZnSnS4 (CZTS) thin films in which the Cu site was partially replaced with Ag were prepared by spray deposition on an Mo-coated glass substrate. Successful replacement of Cu components in the CZTS lattice with Ag up to an Ag/(Cu + Ag) ratio of 0.20 was achieved. Samples with relatively low contents of Ag (Ag/(Cu + Ag) ratios of 0.05 and 0.10) showed obvious grain growth compared to that of bare CZTS, whereas samples with higher Ag contents showed an appreciable decrease in grain sizes. Photoelectrochemical properties for water reduction (H2 production), which was examined after surface modifications with an In2S3/CdS double layer and Pt catalyst for H2 evolution, depended strongly on such morphological differences; a maximum conversion efficiency, i.e., half-cell solar to hydrogen efficiency, of 2.4% was achieved by the photocathode based on the film with an Ag/(Cu + Ag) ratio of 0.10. Minority carrier dynamics examined by photoluminescence measurements indicated that such an active sample of PEC H2 production had a relatively long carrier lifetime, suggesting that the suppression of carrier recombination at grain boundaries in the bulk of these kesterite films is one of the important factors for enhancing PEC functions.

8.
Polymers (Basel) ; 13(18)2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34578017

RESUMEN

(1) Background: Wounds with damages to the subcutaneous are difficult to regenerate because of the tissue damages and complications such as bacterial infection. (2) Methods: In this study, we created burn wounds on pigs and investigated the efficacy of three biomaterials: polycaprolactone-gelatin-silver membrane (PCLGelAg) and two commercial burn dressings, Aquacel® Ag and UrgoTulTM silver sulfadiazine. In vitro long-term antibacterial property and in vivo wound healing performance were investigated. Agar diffusion assays were employed to evaluate bacterial inhibition at different time intervals. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill assays were used to compare antibacterial strength among samples. Second-degree burn wounds in the pig model were designed to evaluate the efficiency of all dressings in supporting the wound healing process. (3) Results: The results showed that PCLGelAg membrane was the most effective in killing both Gram-positive and Gram-negative bacteria bacteria with the lowest MBC value. All three dressings (PCLGelAg, Aquacel, and UrgoTul) exhibited bactericidal effect during the first 24 h, supported wound healing as well as prevented infection and inflammation. (4) Conclusions: The results suggest that the PCLGelAg membrane is a practical solution for the treatment of severe burn injury and other infection-related skin complications.

9.
Respirology ; 26(11): 1049-1059, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34472161

RESUMEN

BACKGROUND AND OBJECTIVE: Influenza virus (FLU), rhinovirus (RV) and respiratory syncytial virus (RSV) are the most common acute respiratory infections worldwide. Infection can cause severe health outcomes, while therapeutic options are limited, primarily relieving symptoms without attenuating the development of lesions or impaired lung function. We therefore examined the inflammatory response to these infections with the intent to identify common components that are critical drivers of immunopathogenesis and thus represent potential therapeutic targets. METHODS: BALB/c mice were infected with FLU, RV or RSV, and lung function, airway inflammation and immunohistopathology were measured over a 10-day period. Anti-IL-17A mAb was administered to determine the impact of attenuating this cytokine's function on the development and severity of disease. RESULTS: All three viruses induced severe airway constriction and inflammation at 2 days post-infection (dpi). However, only FLU induced prolonged inflammation till 10 dpi. Increased IL-17A expression was correlated with the alterations in lung function and its persistence. Neutralization of IL-17A did not affect the viral replication but led to the resolution of airway hyperresponsiveness. Furthermore, anti-IL-17A treatment resulted in reduced infiltration of neutrophils (in RV- and FLU-infected mice at 2 dpi) and lymphocytes (in RSV-infected mice at 2 dpi and FLU-infected mice at 10 dpi), and attenuated the severity of immunopathology. CONCLUSION: IL-17A is a common pathogenic molecule regulating disease induced by three prevalent respiratory viruses. Targeting the IL-17A pathway may provide a unified approach to the treatment of these respiratory infections alleviating both inflammation-induced lesions and difficulties in breathing.


Asunto(s)
Interleucina-17/inmunología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Picornaviridae/inmunología , Infecciones por Virus Sincitial Respiratorio , Animales , Pulmón/fisiopatología , Ratones , Ratones Endogámicos BALB C , Orthomyxoviridae , Virus Sincitiales Respiratorios/inmunología , Rhinovirus
10.
Materials (Basel) ; 14(16)2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-34442997

RESUMEN

The use of naturally occurring materials with antibacterial properties has gained a great interest in infected wound management. Despite being an abundant resource in Vietnam, chitosan and its derivatives have not yet been intensively explored for their potential in such application. Here, we utilized a local chitosan source to synthesize chitosan oligomers (OCS) using hydrogen peroxide (H2O2) oxidation under the microwave irradiation method. The effects of H2O2 concentration on the physicochemical properties of OCS were investigated through molecular weight, degree of deacetylation, and heavy metal contamination for optimization of OCS formulation. Then, the antibacterial inhibition was examined; the minimum inhibitory concentration and minimum bactericidal concentration (MIC and MBC) of OCS-based materials were determined against common skin-inhabitant pathogens. The results show that the local Vietnamese chitosan and its derivative OCS possessed high-yield purification while the molecular weight of OCS was inversely proportional and proportional to the concentration of H2O2, respectively. Further, the MIC and MBC of OCS ranged from 3.75 to less than 15 mg/mL and 7.5-15 mg/mL, respectively. Thus, OCS-based materials induce excellent antimicrobial properties and can be attractive for wound dressings and require further investigation.

11.
Mater Sci Eng C Mater Biol Appl ; 127: 112232, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34225873

RESUMEN

Biodegradable periodic mesoporous organosilica nanoparticles (B-PMO) are an outstanding nanocarrier due to their biodegradability and high drug load capacities. The present study describes a synthesis of a phenylene-containing tetrasulfide based B-PMO, named P4S. The incorporation of aromatic phenylene groups into the framework creates a strong interaction between nanoparticles (NPs) with aromatic rings in the cordycepin molecules. This results in the low release profile under various conditions. In addition, the replacement of this linker slowed the degradation of nanoparticles. The physicochemical properties of the nanoparticles are evaluated and compared with a biodegradable ethane-containing tetrasulfide based PMO and a non-degradable MCM-41. The biodegradability of P4S is also demonstrated in a reducing environment and the 100 nm spherical nanoparticles completely decomposed within 14 days. The porous structure of P4S has a high loading of hydrophilic cordycepin (approximately 731.52 mg g-1) with a slow releasing speed. The release rates of P4S NPs are significantly lower than other materials, such as liposomes, gelatin nanoparticles, and photo-crosslinked hyaluronic acid methacrylate hydrogels, in the same solution. This specific release behavior could guarantee drug therapeutic effects with minimum side-effects and optimized drug dosages. Most importantly, according to the in vitro cytotoxicity study, cordycepin-loaded P4S NPs could retain the toxicity against liver cancer cell (HepG2) while suppressed the cytotoxicity against normal cells (BAEC).


Asunto(s)
Nanopartículas , Portadores de Fármacos , Hidrogeles , Interacciones Hidrofóbicas e Hidrofílicas , Porosidad , Dióxido de Silicio
12.
Risk Manag Healthc Policy ; 14: 2119-2132, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34079399

RESUMEN

AIM: This study measured the level of knowledge, attitudes and practices towards COVID-19 prevention and examined associated factors among patients at a national tertiary general hospital in Vietnam. METHODS: Adult patients admitted to University Medical Center during research period were recruited in a cross-sectional study, which employed a convenience sampling method with a 4-component questionnaire in order to examine the patients' consciousness towards COVID-19 spreading prevention based on four aspects: demographic characteristics (10 items), knowledge (14 items), attitudes (6 items), and practices (7 items). RESULTS: The study involved 2769 respondents (18-90 years) with the mean age of 38.05±13.91 years. About two thirds of the respondents obtained diploma degree or higher (63.4%) and shared their living space with others (64.4%). The majority of patients settled in urban area (74.9%). All participants stayed informed about COVID-19, with the most commonly used channels like television (75.2%), the Internet (72.2%) and phone (69.8%). The vast majority showed sufficient knowledge (93.7%) and positive attitudes (76.3%). Just over half of participants remained good practiced of COVID-19 prevention (57.7%). On average, the factors of younger age, higher educational level, frequency and department of admission, and the number of COVID-19 informative channels were significantly associated with sufficient knowledge, positive attitudes, and good practices regarding preventive action against COVID-19 spreading. The optimistic attitude and having more undergoing chronic diseases were associated with the likelihood of well-practiced COVID-19 preventive measures (OR 3.63, 95% CI 1.54-8.55, p=0.003 and OR 0.86, 95% CI 0.78-0.98, p=0.02, respectively). CONCLUSION: The results of this study demonstrated that the likelihood of good preventive practices in the fight against COVID-19 pandemic was influenced by attitudes and several sociodemographic factors. More drastic interventions for the prevention of COVID-19 should be widely furnished and equipped in hospitals, through various routes to maximize the efficiency and adherence to prevention practices.

13.
JCI Insight ; 6(7)2021 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-33830082

RESUMEN

Virus-induced respiratory tract infections are a major health burden in childhood, and available treatments are supportive rather than disease modifying. Rhinoviruses (RVs), the cause of approximately 80% of common colds, are detected in nearly half of all infants with bronchiolitis and the majority of children with an asthma exacerbation. Bronchiolitis in early life is a strong risk factor for the development of asthma. Here, we found that RV infection induced the expression of miRNA 122 (miR-122) in mouse lungs and in human airway epithelial cells. In vivo inhibition specifically in the lung reduced neutrophilic inflammation and CXCL2 expression, boosted innate IFN responses, and ameliorated airway hyperreactivity in the absence and in the presence of allergic lung inflammation. Inhibition of miR-122 in the lung increased the levels of suppressor of cytokine signaling 1 (SOCS1), which is an in vitro-validated target of miR-122. Importantly, gene silencing of SOCS1 in vivo completely reversed the protective effects of miR-122 inhibition on RV-induced lung disease. Higher miR-122 expression in nasopharyngeal aspirates was associated with a longer time on oxygen therapy and a higher rate of treatment failure in 87 infants hospitalized with moderately severe bronchiolitis. These results suggest that miR-122 promotes RV-induced lung disease via suppression of its target SOCS1 in vivo. Higher miR-122 expression was associated with worse clinical outcomes, highlighting the potential use of anti-miR-122 oligonucleotides, successfully trialed for treatment of hepatitis C, as potential therapeutics for RV-induced bronchiolitis and asthma exacerbations.


Asunto(s)
Bronquitis/terapia , Enfermedades Pulmonares/virología , MicroARNs/genética , Infecciones por Picornaviridae/genética , Proteína 1 Supresora de la Señalización de Citocinas/genética , Animales , Antagomirs/farmacología , Bronquitis/virología , Quimiocina CXCL1/metabolismo , Quimiocina CXCL2/metabolismo , Femenino , Humanos , Lactante , Enfermedades Pulmonares/genética , Enfermedades Pulmonares/terapia , Masculino , Ratones Endogámicos BALB C , Nasofaringe/virología , Infecciones por Picornaviridae/tratamiento farmacológico , Rhinovirus/fisiología , Proteína 1 Supresora de la Señalización de Citocinas/metabolismo , Insuficiencia del Tratamiento , Replicación Viral
14.
Int J Biol Macromol ; 177: 360-369, 2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-33631259

RESUMEN

Hematin has been used as an alternative enzyme catalyst to horseradish peroxidase (HRP) due to its iron-containing activity center. Although hematin and it derivatives have been widely used for polymerization of phenol/analine compounds, it has some drawbacks such as the limited solubility and reaction only at high pH condition. Herein, we report a nanosized biomimetic catalyst, hematin-decorated polyamidoamine dendrimer (G3.0-He) that can effectively catalyze the in situ hydrogelation of phenol-conjugated polymers under neutral pH condition. We demonstrate that G3.0-He particles are smaller than 100 nm and have excellent enzyme-mimetic functions. Interestingly, the nanosized catalyst is not inactivated at high H2O2 concentration. Compared to pure hematin, G3.0-He has significantly higher dispersion in acidic and neutral media, and preserves the percentage of survival of fibroblasts over 90%. Notably, G3.0-He possesses an exquisite HRP-mimicking activity in gelation of gelatin derivative with phenolic hydroxyl (tyamine) moieties under mild physiological conditions. The in vitro study demonstrated that Gel-Tyr hydrogel by G3.0-He catalyzed reaction had excellent cytocompatibility and an excellent scaffold for adhesion to fibroblast cells. Therefore, the designed minimalistic G3.0-He catalyst could serve as an effective catalytic alternative for HRP enzyme in the preparation of biomedical hydrogels.


Asunto(s)
Materiales Biomiméticos , Dendrímeros , Fibroblastos/metabolismo , Hemina , Ensayo de Materiales , Nanopartículas/química , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Línea Celular , Dendrímeros/química , Dendrímeros/farmacología , Hemina/química , Hemina/farmacología , Peroxidasa de Rábano Silvestre/química , Peroxidasa de Rábano Silvestre/farmacología , Humanos
15.
Mater Sci Eng C Mater Biol Appl ; 120: 111724, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33545875

RESUMEN

Wound dressings are typically used to provide a favorable environment supporting the intricate process of wound healing. This research aims to fabricate and evaluate an electrospun polycaprolactone (EsPCL) membrane coated with various densities of chitosan oligomers (COS) - a biological agent - for application as bioactive wound dressing. Weight calculation was employed to investigate the density of COS coated onto the electrospun PCL membrane. Physicochemical characteristics of the prepared membranes, such as hydrophilicity and mechanical properties were demonstrated and evaluated through standard experimental methods. In vitro assays and mice model were used to investigate the antibacterial activities, cytocompatibility, hemostasis and the in vivo interaction of the membranes. The results showed that COS was coated successfully on the surface of the polymeric membrane, altering its morphology and associated characteristics. The greater concentration of COS led to an increase in the thickness of the membrane, which resulted in stronger antibacterial activities. Moreover, the increase of chitosan oligomers density in the membrane induced faster hemostasis and affected the re-epithelialization and wound healing in mice. Thus, the membrane as a whole and particularly chitosan oligomers were shown to be potential for further studies regarding wound dressing.


Asunto(s)
Quitosano , Animales , Vendajes , Ratones , Poliésteres , Cicatrización de Heridas
16.
Biomedicines ; 9(1)2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33401484

RESUMEN

Bone cement is used as a mortar for securing bone implants, as bone void fillers or as spacers in orthopaedic surgery. Antibiotic-loaded bone cements (ALBCs) have been used to prevent and treat prosthetic joint infections by providing a high antibiotic concentration around the implanted prosthesis. High antibiotic concentrations are, on the other hand, often associated with tissue toxicity. Controlling antibiotic release from ALBCS is key to achieving effective infection control and promoting prosthesis integration with the surrounding bone tissue. However, current ALBCs still need significant improvement in regulating antibiotic release. In this review, we first provide a brief introduction to prosthetic joint infections, and the background concepts of therapeutic efficacy and toxicity in antibiotics. We then review the current state of ALBCs and their release characteristics before focusing on the research and development in controlling the antibiotic release and osteo-conductivity/inductivity. We then conclude by a discussion on the need for better in vitro experiment designs such that the release results can be extrapolated to predict better the local antibiotic concentrations in vivo.

17.
Nanomaterials (Basel) ; 10(11)2020 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-33203046

RESUMEN

Bacterial biofilms are involved in most device-associated infections and remain a challenge for modern medicine. One major approach to addressing this problem is to prevent the formation of biofilms using novel antimicrobial materials, device surface modification or local drug delivery; however, successful preventive measures are still extremely limited. The other approach is concerned with treating biofilms that have already formed on the devices; this approach is the focus of our manuscript. Treating biofilms associated with medical devices has unique challenges due to the biofilm's extracellular polymer substance (EPS) and the biofilm bacteria's resistance to most conventional antimicrobial agents. The treatment is further complicated by the fact that the treatment must be suitable for applying on devices surrounded by host tissue in many cases. Nanomaterials have been extensively investigated for preventing biofilm formation on medical devices, yet their applications in treating bacterial biofilm remains to be further investigated due to the fact that treating the biofilm bacteria and destroying the EPS are much more challenging than preventing adhesion of planktonic bacteria or inhibiting their surface colonization. In this highly focused review, we examined only studies that demonstrated successful EPS destruction and biofilm bacteria killing and provided in-depth description of the nanomaterials and the biofilm eradication efficacy, followed by discussion of key issues in this topic and suggestion for future development.

18.
J Immunol ; 205(9): 2468-2478, 2020 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-32948685

RESUMEN

Rhinovirus (RV) infections in asthmatic patients are often associated with asthma exacerbation, characterized by worsened airways hyperreactivity and increased immune cell infiltration to the airways. The C-X-C chemokines, CXCL3 and CXCL5, regulate neutrophil trafficking to the lung via CXCR2, and their expression in the asthmatic lung is associated with steroid-insensitive type 2 inflammatory signatures. Currently, the role of CXCL3 and CXCL5 in regulating neutrophilic and type 2 responses in viral-induced asthma exacerbation is unknown. Inhibition of CXCL3 or CXCL5 with silencing RNAs in a mouse model of RV-induced exacerbation of asthma attenuated the accumulation of CXCR2+ neutrophils, eosinophils, and innate lymphoid cells in the lung and decreased production of type 2 regulatory factors IL-25, IL-33, IL-5, IL-13, CCL11, and CCL24. Suppression of inflammation was associated with decreased airways hyperreactivity, mucus hypersecretion, and collagen deposition. Similar results were obtained by employing RC-3095, which has been shown to bind to CXCR2, or by depletion of neutrophils. Our data demonstrate that CXCL3 and CXCL5 may be critical in the perpetuation of RV-induced exacerbation of asthma through the recruitment of CXCR2-positive neutrophils and by promoting type 2 inflammation. Targeting the CXCL3/CXCL5/CXCR2 axis may provide a new therapeutic approach to attenuating RV-induced exacerbations of asthma.


Asunto(s)
Asma/inmunología , Quimiocina CXCL5/inmunología , Quimiocinas CXC/inmunología , Quimiotaxis de Leucocito/inmunología , Neutrófilos/inmunología , Receptores de Interleucina-8B/inmunología , Rhinovirus/inmunología , Animales , Hiperreactividad Bronquial/inmunología , Eosinófilos/inmunología , Inmunidad Innata/inmunología , Inflamación/inmunología , Pulmón/inmunología , Linfocitos/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C
19.
RSC Adv ; 10(51): 30858-30869, 2020 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-35516028

RESUMEN

The development of improved methods for the synthesis of monodisperse gold nanoparticles (Au NPs) is of high priority because they can be used as substrates for surface-enhanced Raman scattering (SERS) applications relating to biological lipids. Herein, Au NPs have been successfully synthesized via a seed-mediated growth method. The LSPR peak is controlled via adjusting the gold nanoseed component, and different fabrication methods were studied to establish the effect of sonication time on NP size. The simple, facile, and room-temperature method is based on a conventional ultrasonic bath, which leads to ultrasonic energy effects on the size and morphology of the Au NPs. This research offers new opportunities for the production of highly monodispersed spherical Au NPs without the use of a magnetic stirrer method, as evidenced by ultraviolet-visible reflectance spectra and scanning electron microscopy (SEM) analysis. SEM images indicate that the spherical Au NP colloidal particles are stable and reliable, which paves the way for their use as a nanostructured biosensor platform that can be exploited for multiple applications, for example, in materials science, sensing, catalysis, medicine, food safety, biomedicine, etc. The highest enhancement factor that could be achieved in terms of the SERS enhancement activity of these Au NP arrays was determined using 10-9 M serotonin (5-hydroxytryptamine, 5-HT) as the Raman probe molecules.

20.
Antioxidants (Basel) ; 8(8)2019 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-31382466

RESUMEN

Phyllanthus emblica is an edible nutraceutical and functional food in the Asia area with medicinal and nutritive importance. The fruit extract of P. emblica is currently considered to be one of the effective functional foods for flesh maintenance and disease treatments because of its antioxidative and immunomodulatory properties. We examined the antioxidant abilities of the fruit extract powder by carrying out 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, iron reducing power, and metal chelating activity analysis and showed excellent antioxidative results. In 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the result showed that the samples had no cytotoxic effect on RAW 264.7 cells even at a high concentration of 2 mg/mL. To investigate its immunomodulatory function, our estimation was to treat it with lipopolysaccharide (LPS) in RAW 264.7 cells to present anti-inflammatory capacities. The extract decreased reactive oxygen species (ROS) production levels in a dose-dependent manner measured by flow cytometry. We also examined various inflammatory mRNAs and proteins, including nuclear factor-κB (NF-κB), inducible nitric oxide synthases (iNOS), and cyclooxygenase-2 (COX-2). In quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting assay, all three targets were decreased by the extract, also in a dose-dependent manner. In conclusion, P. emblica fruit extract powder not only lessened antioxidative stress damages, but also inhibited inflammatory reactions.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...