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1.
Eur Phys J E Soft Matter ; 47(7): 47, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39002103

RESUMO

In intracellular transports, motor proteins transport macromolecules as cargos to desired locations by moving on biopolymers such as microtubules. Recent experiments suggest that, while moving in crowded environments, cargos that can associate motor proteins during their translocation have larger run-length and association time compared to free motors. Here, we model the dynamics of a cargo that can associate at the most m free motors present on the microtubule track as obstacles to its motion. The proposed models display competing effects of association and crowding, leading to a peak in the run-length with the free-motor density. For m = 2 and 3, we show that this feature is governed by the largest eigenvalue of the transition matrix describing the cargo dynamics. In all the above cases, free motors are assumed to be present on the microtubule as stalled obstacles. We finally compare simulation results for the run-length for general scenarios where the free motors undergo processive motion in addition to binding and unbinding to or from the microtubule.


Assuntos
Microtúbulos , Modelos Biológicos , Proteínas Motores Moleculares , Microtúbulos/metabolismo , Microtúbulos/química , Proteínas Motores Moleculares/metabolismo , Proteínas Motores Moleculares/química , Transporte Biológico
2.
Polymers (Basel) ; 16(13)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-39000733

RESUMO

Heart problems are quite prevalent worldwide. Cardiomyocytes and stem cells are two examples of the cells and supporting matrix that are used in the integrated process of cardiac tissue regeneration. The objective is to create innovative materials that can effectively replace or repair damaged cardiac muscle. One of the most effective and appealing 3D/4D scaffolds for creating an appropriate milieu for damaged tissue growth and healing is hydrogel. In order to successfully regenerate heart tissue, bioactive and biocompatible hydrogels are required to preserve cells in the infarcted region and to bid support for the restoration of myocardial wall stress, cell survival and function. Heart tissue engineering uses a variety of hydrogels, such as natural or synthetic polymeric hydrogels. This article provides a quick overview of the various hydrogel types employed in cardiac tissue engineering. Their benefits and drawbacks are discussed. Hydrogel-based techniques for heart regeneration are also addressed, along with their clinical application and future in cardiac tissue engineering.

3.
Gels ; 10(6)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38920944

RESUMO

Hospital-acquired infections are considered a priority for public health systems since they pose a significant burden for society. High-touch surfaces of healthcare centers, including textiles, provide a suitable environment for pathogenic bacteria to grow, necessitating incorporating effective antibacterial agents into textiles. This paper introduces a highly durable antibacterial gel-like solution, Silver Shell™ finish, which contains chitosan-bound silver chloride microparticles. The study investigates the coating's environmental impact, health risks, and durability during repeated washing. The structure of the Silver Shell™ finish was studied using transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). The TEM images showed a core-shell structure, with chitosan forming a protective shell around groupings of silver microparticles. The field-emission scanning electron microscopy (FESEM) demonstrated the uniform deposition of Silver Shell™ on the surfaces of the fabrics. AATCC Test Method 100 was employed to quantitatively analyze the antibacterial properties of the fabrics coated with silver microparticles. Two types of bacteria, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), were used in this study. The antibacterial results showed that after 75 wash cycles, a 100% reduction for both S. aureus and E. coli in the coated samples using crosslinking agents was observed. The coated samples without a crosslinking agent exhibited 99.88% and 99.81% reductions for S. aureus and E. coli after 50 washing cycles. To compare the antibacterial properties toward non-pathogenic and pathogenic strains of the same species, MG1655 model E. coli strain (ATCC 29213) and a multidrug-resistant clinical isolate were used. The results showed the antibacterial efficiency of the Silver ShellTM solution (up to 99.99% reduction) coated on cotton fabric. AATCC-147 was performed to investigate the coated samples' leaching properties and the crosslinking agent's effects against S. aureus and E. coli. All coated samples demonstrated remarkable antibacterial efficacy, even after 75 wash cycles. The crosslinking agent facilitated durable attachment between the silver microparticles and cotton substrate, minimizing the release of particles from the fabrics. Color measurements were conducted to assess the color differences resulting from the coating process. The results indicated fixation values of 44%, 32%, and 28% following 25, 50, and 75 washing cycles, respectively.

4.
ArXiv ; 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38745707

RESUMO

Hospital-acquired infections are considered a priority for public health systems, which poses a significant burden for society. High-touch surfaces of healthcare centers, including textiles, provide a suitable environment for pathogenic bacteria to grow, necessitating incorporating effective antibacterial agents into textiles. This paper introduces a highly durable antibacterial gel-like solution, Silver Shell finish, which contains chitosan-bound silver chloride microparticles. The study investigates the coating's environmental impact, health risks, and durability during repeated washing. The structure of the Silver Shell finish was studied using Transmission Electron Microscopy (TEM) and Energy-Dispersive X-ray Spectroscopy (EDX). TEM images showed a core-shell structure, with chitosan forming a protective shell around groupings of silver micro-particles. Field Emission Scanning Electron Microscopy (FESEM) demonstrated the uniform deposition of Silver Shell on the surface of fabrics. AATCC Test Method 100 was employed to quantitatively analyze the antibacterial properties of fabrics coated with silver microparticles. Two types of bacteria, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were used in this study. The antibacterial results showed that after 75 wash cycles, a 100% reduction for both S. aureus and E. coli in the coated samples using crosslinking agents was observed. The coated samples without a crosslinking agent exhibited a 99.88% and 99.81% reduction for S. aureus and E. coli after 50 washing cycles. AATCC-147 was performed to investigate the coated samples' leaching properties and the crosslinking agent's effect against S. aureus and E. coli. All coated samples demonstrated remarkable antibacterial efficacy even after 75 wash cycles.

5.
Phys Chem Chem Phys ; 26(7): 6372-6385, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38315058

RESUMO

Self-assembly of ethylene oxide (EO)-propylene oxide (PO)-based star-shaped block copolymers (BCPs) in the presence of different kinds of additives is investigated in an aqueous solution environment. Commercially available four-armed BCPs, namely Tetronics® (normal: T904 with EO as the terminal end block; and reverse: T90R4 with PO as the terminal end block), each with 40%EO, are used. The effect of various additives such as electrolytes (NaCl and Na2SO4), nonelectrolyte polyols (glucose and sorbitol), and ionic surfactants (viz. anionic-sodium dodecyl sulfate (SDS), cationic-dodecyltrimethylammonium bromide (DTAB) and zwitterionic dodecyldimethylammonium propane sulfonate (C12PS)) on these BCPs is examined to observe their influence on micellization behaviour. The presence of salts and polyols displayed interesting phase behaviour, i.e., the cloud point (CP) was decreased, the water structure was affected and the micelles were dehydrated by expelling water molecules, and thus they were likely to promote micelle formation/growth. In contrast, ionic surfactants in small amounts interacted with the BCPs and showed an increase in CPs thereby forming mixed micelles with increasing charges and decreasing micellar sizes, finally transforming to small surfactant-rich mixed micelles. Molecular interactions such as electrostatic and hydrogen bonding involved within the examined entities are put forth employing a computational simulation approach using the Gaussian 09 window for calculation along with the GaussView 5.0.9 programming software using the (DFT)/B3LYP method and 3-21G basis set. The hydrodynamic diameter (Dh) of the micelles is examined using dynamic light scattering (DLS), while the various micellar parameters inferring the shape/geometry are obtained using small-angle neutron scattering (SANS) by the best fitting of the structure factors. It is observed that 10 w/v% T904 remains as spherical micelles with some micellar growth under physiological conditions (37 °C), while 10 w/v% T90R4 remains as unimers and forms spherical micelles in the presence of additives at 37 °C. Furthermore, the additive-induced micellar systems are tested as developing nanovehicles for anticancer (curcumin, Cur) drug solubilization using UV-vis spectroscopy, which shows a prominent increase in absorbance with enhanced solubilization capacity. Additionally, the cytotoxic effect of Cur loaded on the BCP micelles in HeLa cells is studied through confocal microscopy by capturing fluorescence images that depict HeLa cell growth inhibition under the influence of additive-induced micellar systems.

6.
Electrophoresis ; 45(9-10): 933-947, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38416600

RESUMO

Biological material is routinely collected at crime scenes and from exhibits and is a key type of evidence during criminal investigations. Touch or trace DNA samples from surfaces and objects deemed to have been contacted are frequently collected. However, a person of interest may not leave any traces on contacted surfaces, for example, if wearing gloves. A novel means of sampling human DNA from air offers additional avenues for DNA collection. In the present study, we report on the results of a pilot study into the prevalence and persistence of human DNA in the air. The first aspect of the pilot study investigates air conditioner units that circulate air around a room, by sampling units located in four offices and four houses at different time frames post-cleaning. The second aspect investigates the ability to collect human DNA from the air in rooms, with and without people, for different periods of time and with different types of collection filters. Results of this pilot study show that human DNA can be collected on air conditioner unit surfaces and from the air, with air samples representing the more recent occupation while air conditioner units showing historic use of the room.


Assuntos
DNA , Manejo de Espécimes , Humanos , DNA/análise , Projetos Piloto , Manejo de Espécimes/métodos , Ar/análise , Ar Condicionado
7.
Br Dent J ; 236(2): 111-116, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38278908

RESUMO

Introduction Oral manifestations have been observed with this condition; however, little is known about their impact on the healthcare professionals routinely managing these patients.Aims To investigate the prevalence of the oral manifestations of long COVID and the healthcare professionals' views, experiences and practices for managing these conditions.Materials and methods A cross-sectional mixed-methods study, including a self-reported online questionnaire (n = 104) and healthcare professionals' (n = 7) semi-structured interviews, was conducted. Descriptive statistics and reflexive thematic analysis were used to analyse the data.Results In total, 78% of respondents reported one or more oral conditions associated with COVID-19. Changes in the sense of taste and/or smell (58%), dry mouth (48.1%) and mouth sores (45.7%) were frequently reported. Themes identified from healthcare professionals' interviews were areas for research, management and interdisciplinary collaboration.Discussion Allied healthcare professionals may assist dental professionals with managing oral manifestations of long COVID. Inadequate access to NHS dentistry is deterring patients worried about their oral symptoms and the limited oral knowledge of healthcare professionals affects their ability to manage patients.Conclusion Healthcare professionals have observed oral manifestations in individuals diagnosed with long COVID; however, further information and training on this topic would assist them with managing patients and increasing awareness among clinicians.


Assuntos
COVID-19 , Síndrome de COVID-19 Pós-Aguda , Humanos , Estudos Transversais , COVID-19/epidemiologia , Pesquisa Qualitativa , Pessoal de Saúde , Atitude do Pessoal de Saúde
8.
Int J Biol Macromol ; 254(Pt 2): 127794, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37923035

RESUMO

In this epoch, the disposal of multipollutant wastewater inevitably compromises life on Earth. In this study, the inclusion of Bacterial cellulose microfilaments reinforced chitosan adorned with melamine 2D plates creates a unique 3D bead structure for anionic dye removal. The establishment of an imine network between melamine and chitosan, along with the quantity of inter- and intra­hydrogen bonds, boosts the specific surface area to 106.68 m2.g-1. Removal efficiency and in-depth comprehension of synthesized adsorbent characteristics were assessed using batch adsorption experiments and characterization methods. Additionally, pH, adsorbent quantity, time, beginning concentration of solution, and temperature were analyzed and optimized as adsorption essential factors. Owing to the profusion of hydroxyl, amine, imine functional groups and aromatic rings, the synthesized adsorbent intimated an astonishing maximum adsorption capacity of 3168 mg.g-1 in Congo red dye removal at pH 5.5. Based on the kinetic evaluation, pseudo-second-order (R2 = 0.999), pseudo-first-order (R2 = 0.964), and Avrami (R2 = 0.986) models were well-fitted with the kinetic results among the seven investigated models. The isothermal study reveals that the adsorption mechanism predominantly follows the Redlich-Peterson (R2 = 0.996), Koble-Carrigan, and Hill isotherm models (R2 = 0.994). The developed semi-natural sorbent suggests high adsorption capacity, which results from its exceptional structure, presenting promising implications for wastewater treatment.


Assuntos
Quitosana , Poluentes Químicos da Água , Vermelho Congo/química , Quitosana/química , Celulose/química , Adsorção , Cinética , Iminas , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio
9.
Indian J Med Microbiol ; 46: 100465, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37690316

RESUMO

PURPOSE: Cryptococcus neoformans is an encapsulated yeast. It is a significant pathogen among immunocompromised people with HIV & Non-HIV vulnerable populations. These conditions include cancer, corticosteroid usage, immunosuppression following sarcoidosis, organ transplantation, immunosuppressive medication, and liver cirrhosis. In cirrhotic, it accounts for 6-21% of systemic infections. METHODS: The retrospective study was conducted in tertiary care hepatobiliary center in New Delhi, India. Samples of blood, cerebrospinal fluid (CSF), urine, body fluids, and serum were processed for gram stain, India ink, fungal culture and identification, and cryptococcal antigen. Antifungal susceptibility was assessed using the micro-broth dilution technique. RESULTS: 30 patients with cryptococcal infection were analysed, and 40 isolates from various samples were recovered. Out of 40 samples, C. neoformans was isolated from blood (62.5%), urine (15%), ascitic fluid (10%), MiniBAL (5%), bone marrow, CSF, and pleural fluid in one sample each. India ink positivity was 56% and all samples were positive for Cryptococcal antigen. Alcoholic liver disease & Hepatitis B & C associated chronic liver disease were seen in 43% & 20% of patients. Other underlying conditions were diabetes mellitus (20%), TB (10%), autoimmune hepatitis (6.6%), autoimmune disease (autoimmune hemolytic anemia, Sjogren syndrome) (6.6%), sarcoidosis (3.3%), hepatocellular carcinoma (3.3%). 7.5%, 5%, 2.5%, 7.5%, and 2.5% of C. neoformans strains were the non-wild type to fluconazole, 5-fluorocytosine, amphotericin B, posaconazole, and itraconazole respectively, but all strains were wildtype to voriconazole. CONCLUSION: According to the study liver conditions are a significant risk factor for cryptococcal infection. Therefore, cryptococcal isolation and antifungal susceptibility testing, as well as appropriate antifungal drug use, should be studied and paid attention too.


Assuntos
Criptococose , Cryptococcus neoformans , Infecções por HIV , Hepatopatias , Meningite Criptocócica , Sarcoidose , Humanos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Meningite Criptocócica/líquido cefalorraquidiano , Meningite Criptocócica/epidemiologia , Meningite Criptocócica/microbiologia , Estudos Retrospectivos , Atenção Terciária à Saúde , Testes de Sensibilidade Microbiana , Criptococose/tratamento farmacológico , Fluconazol/uso terapêutico , Hepatopatias/tratamento farmacológico , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Infecções por HIV/tratamento farmacológico
10.
J Midwifery Womens Health ; 67(6): 759-769, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36433698

RESUMO

The positive effects of the CenteringPregnancy group antenatal care (ANC) model on perinatal outcomes in the United States has led to its adaptation and implementation in many low- and middle-income countries. Facilitative discussions are a core component of this group ANC model. Facilitator training lays a critical foundation for delivery of this paradigm-shifting model as practitioners learn to adapt their approach to health education from didactive to facilitative. However, there is little rigorous research focused on best practices for training group health care facilitators and none that is guided by a theoretical framework. Kolb's experiential learning theory offers a theoretical framework to guide the development of training workshops that allow trainees to experience, reflect on, and practice the facilitation skills needed to deliver this evidence-based intervention. This article describes an experiential learning-based training workshop that was implemented as part of an ongoing effectiveness-implementation trial of a Centering-based group ANC model in Blantyre District, Malawi. We provide a blueprint for conducting group ANC facilitator trainings that, in addition to imparting knowledge, effectively builds confidence and buy-in to this paradigm-changing approach to ANC delivery. This blueprint can be adapted for use in designing and implementing group health care across settings in the United States and globally.


Assuntos
Cuidado Pré-Natal , Aprendizagem Baseada em Problemas , Feminino , Gravidez , Humanos , Malaui , Atenção à Saúde , Aprendizagem
11.
Polymers (Basel) ; 14(21)2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36365696

RESUMO

Self-assembly of amphiphilic block copolymers display a multiplicity of nanoscale periodic patterns proposed as a dominant tool for the 'bottom-up' fabrication of nanomaterials with different levels of ordering. The present review article focuses on the recent updates to the self-association of amphiphilic block copolymers in aqueous media into varied core-shell morphologies. We briefly describe the block copolymers, their types, microdomain formation in bulk and micellization in selective solvents. We also discuss the characteristic features of block copolymers nanoaggregates viz., polymer micelles (PMs) and polymersomes. Amphiphilic block copolymers (with a variety of hydrophobic blocks and hydrophilic blocks; often polyethylene oxide) self-assemble in water to micelles/niosomes similar to conventional nonionic surfactants with high drug loading capacity. Double hydrophilic block copolymers (DHBCs) made of neutral block-neutral block or neutral block-charged block can transform one block to become hydrophobic under the influence of a stimulus (physical/chemical/biological), and thus induced amphiphilicity and display self-assembly are discussed. Different kinds of polymer micelles (viz. shell and core-cross-linked, core-shell-corona, schizophrenic, crew cut, Janus) are presented in detail. Updates on polymerization-induced self-assembly (PISA) and crystallization-driven self-assembly (CDSA) are also provided. Polyion complexes (PICs) and polyion complex micelles (PICMs) are discussed. Applications of these block copolymeric micelles and polymersomes as nanocarriers in drug delivery systems are described.

12.
Soft Matter ; 18(24): 4543-4553, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35674288

RESUMO

This study scrutinizes the self-association of ethylene oxide (EO)-propylene oxide (PO)-based star-shaped block copolymers as normal Tetronic® (T904) and reverse Tetronic® R (T90R4) with varying molecular characteristics and different hydrophilic-hydrophobic ratios in an aqueous solution environment. These thermo-responsive solutions appear clear, transparent or bluish up to 10%w/v, which anticipated the probable transition of unimers to spherical or ellipsoidal micelles which is complemented by scattering experiments. In a single-solution environment, 10%w/v T904 formed star-shaped micelles at ambient temperature and exhibited a micellar growth/transition with temperature ageing. While 10%w/v T90R4 exists as unimers or a Gaussian coil over a wide range of temperature. Very interestingly, close to the cloud point (CP) flower-shaped spherical and ellipsoidal micelles were formed. A similar proposed micellar scheme was also examined for mixed systems T904 : T90R4 in varying ratios (1 : 0, 3 : 1, 1 : 1, 1 : 3 and 0 : 1) giving an account to the solution behavior of the mixtures. An amalgamation of dynamic light scattering (DLS) and small-angle neutron scattering (SANS) techniques achieved the thorough extraction of the structural parameters of the micellar system. The hydrodynamic diameter (Dh) of the micelles with temperature variation was evaluated from dynamic light scattering (DLS) while the structure factor of the micelles was found by employing small-angle neutron scattering (SANS). Furthermore, the single and mixed micellar systems were quantitatively and qualitatively examined for anticancer drug solubilization using UV-vis spectroscopy for their superior use as potential nanocargos.


Assuntos
Micelas , Água , Difusão Dinâmica da Luz , Interações Hidrofóbicas e Hidrofílicas , Espalhamento a Baixo Ângulo , Água/química
13.
Br J Oral Maxillofac Surg ; 60(7): 978-982, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35773114

RESUMO

Despite forming the majority in undergraduate medicine and dentistry programmes, females remain under-represented in all surgical specialties, including oral and maxillofacial surgery (OMFS). Efforts are ongoing to promote female uptake in surgery. Research output is a key metric in measuring leadership and academic advancement within a specialty. The aim of this study was to assess female authorship in research published in the British Journal of Oral and Maxillofacial Surgery from 2000-2020 with a retrospective cohort study of original articles and reviews published in the journal from five different volumes of the journal (2000, 2005, 2010, 2015, 2020 as representative time points). The gender of the first and last authors were assessed for gender by first name recognition and verified with a web-search of the author using their stated institutional affiliation when this was not clear. Articles were excluded if the gender of one of the first or last author could not be determined. A total of 501 articles were included with the gender of 1002 authors analysed. 173 (17.3%) authors were female, and 828 (82.7%) were male. The most common author combination was male-male (70.3%) and the least common female-female (4.8%). The proportion of female authors increased over time from 9.3% in 2000 to 23.4% in 2020. Females remain under-represented within surgery, but female presence in academic output is increasing at a similar rate to the numbers of female uptake in the clinical workforce which is a promising sign and indicative of progress towards gender parity.


Assuntos
Autoria , Cirurgia Bucal , Bibliometria , Feminino , Humanos , Liderança , Masculino , Estudos Retrospectivos
14.
BMC Pregnancy Childbirth ; 21(1): 790, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34819018

RESUMO

BACKGROUND: HIV testing at antenatal care (ANC) is critical to achieving zero new infections in sub-Saharan Africa. Although most women are tested at ANC, they remain at risk for HIV exposure and transmission to their infant when their partners are not tested. This study evaluates how an HIV-enhanced and Centering-based group ANC model-Group ANC+ that uses interactive learning to practice partner communication is associated with improvements in partner HIV testing during pregnancy. METHODS: A randomized pilot study conducted in Malawi and Tanzania found multiple positive outcomes for pregnant women (n = 218) assigned to Group ANC+ versus individual ANC. This analysis adds previously unpublished results for two late pregnancy outcomes: communication with partner about three reproductive health topics (safer sex, HIV testing, and family planning) and partner HIV testing since the first antenatal care visit. Multivariate logistic regression models were used to assess the effect of type of ANC on partner communication and partner testing. We also conducted a mediation analysis to assess whether partner communication mediated the effect of type of care on partner HIV testing. RESULTS: Nearly 70% of women in Group ANC+ reported communicating about reproductive health with their partner, compared to 45% of women in individual ANC. After controlling for significant covariates, women in group ANC were twice as likely as those in individual ANC to report that their partner got an HIV test (OR 1.99; 95% CI: 1.08, 3.66). The positive effect of the Group ANC + model on partner HIV testing was fully mediated by increased partner communication. CONCLUSIONS: HIV prevention was included in group ANC health promotion without compromising services and coverage of standard ANC topics, demonstrating that local high-priority health promotion needs can be integrated into ANC using a Group ANC+. These findings provide evidence that greater partner communication can promote healthy reproductive behaviors, including HIV prevention. Additional research is needed to understand the processes by which group ANC allowed women to discuss sensitive topics with partners and how these communications led to partner HIV testing.


Assuntos
Infecções por HIV/diagnóstico , Teste de HIV , Relações Interpessoais , Cuidado Pré-Natal/métodos , Adulto , Feminino , Promoção da Saúde , Humanos , Malaui , Projetos Piloto , Gravidez , Distribuição Aleatória , Parceiros Sexuais , Tanzânia , Adulto Jovem
15.
J Phys Chem B ; 124(51): 11750-11761, 2020 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-33305575

RESUMO

Ethylene oxide (EO)-butylene oxide (BO)-ethylene oxide (EO)-based triblock copolymers with varying hydrophilic-hydrophobic ratios in arrangement, generally referred to as EBE, were scrutinized in an aqueous environment. Various self-associative (micellization) physicochemical properties of these EBEs were examined at different temperatures unified with a quantum chemical study. The salting-out effect on 5%w/v EBE was examined by observing their aqueous solution behavior where the clear transparent solution/turbidity suggested the probable presence of spherical or ellipsoidal micelles, which was confirmed from the scattering outline. The hydrodynamic radius (Dh) of the formed micellar geometry as a function of temperature and electrolyte (2 M NaCl) was inspected from dynamic light scattering and further supported by small-angle neutron scattering, where the Q-range prototype and scattering parameters were evaluated by the best fitting of the structure factor. Furthermore, these micelles were employed as potential nanocarriers for anticancer (curcumin and quercetin) drugs, where its release profile at a particular time interval was estimated using UV-vis spectroscopy. Different kinetic models were employed to fit the release profile data that enabled this study to act as an ideal platform for drug delivery. Also, the plausible interactions between EO-BO-EO blocks and the anticancer drugs were inferred from the evaluated computational descriptors.


Assuntos
Antineoplásicos , Óxido de Etileno , Alcenos , Micelas , Polímeros
16.
Drug Dev Ind Pharm ; 46(10): 1622-1631, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32816575

RESUMO

OBJECTIVE: This research study attempted to develop spray-dried solid dispersion, to enhance the solubility of repaglinide, an antidiabetic drug. SIGNIFICANCE: Aqueous solubility plays a major role in drug delivery because any chemical entity has to be in a dissolved state at the site of absorption, in order to get absorbed. Solid dispersion (SD) is one of the widely used techniques to enhance solubility and hence dissolution rate of poorly soluble drugs. METHODS: Repagnilide, in hypromellose acetate succinate (HPMCAS) solution, was dried by spray drying to obtain spray-dried solid dispersion (SDSD). Plackett-Burman and Box-Behnken designs were used for screening formulation as well as process parameters, and optimization respectively. DSC, XRD, SEM were carried out to confirm the preparation of solid dispersion. SDSD was evaluated for in vitro dissolution, flow properties, Percentage yield and in vivo oral glucose tolerance test. RESULT: Spray dried solid dispersion comprising (w/w) drug:polymer ratio of 1:3.82, 2.56% of aerosil and inlet temperature of 90 °C, corresponded to the best formulation obtained in this work. It showed t 85% of less than 15 min and a significant reduction in blood glucose level in rats as compared to pure drug and marketed formulation. CONCLUSION: Thus, it can be concluded that spray-dried solid dispersion prepared using HPMCAS is a useful technique for solubility and dissolution enhancement of repaglinide.


Assuntos
Química Farmacêutica , Preparações Farmacêuticas , Acetatos/química , Animais , Carbamatos/química , Derivados da Hipromelose , Piperidinas/química , Ratos , Solubilidade , Succinatos/química
18.
Phys Chem Chem Phys ; 21(28): 15584-15594, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31268439

RESUMO

Interaction of an anionic diazo dye, Congo red (CR), with conventional surfactants: cetyltrimethylammonium bromide (CTAB) and Gemini surfactant: N,N'-dihexadecyl-N,N,N',N'-tetramethyl-N,N'-ethanediyl-diammonium dibromide (16-2-16), in their pre-micellar and post-micellar concentration regions has been investigated using conductometry, surface tensiometry, UV-visible spectroscopy, fluorescence spectroscopy, dynamic light scattering (DLS), cyclic voltammetry (CV) and linear sweep voltammetry (LSV) techniques. Various interfacial, micellar, band gap and electrochemical parameters are estimated at 303.15 K. The observed results are explained in terms of critical micelle concentration (CMC) of the individual surfactants and their ability to undergo aggregation in the presence of dianionic CR. It is found that the CMC of both the surfactants decreases in the presence of CR, which is attributed to the electrostatic attraction, short-range π-π stacking of CR molecules, and the hydrophobic forces operating between CR and the surfactant molecules. The spectral results for CR showed a hypsochromic (blue) shift below the CMC for both the surfactants, which indicates the resultant CR-surfactant complexation through ion-pair formation, which further inferred H-aggregation of CR in the pre-micellar region. Above the CMC, CR reverts back to its monomeric state and gets bound to the micelle. Job's method is employed to determine the stoichiometric ratio between CR and the individual surfactant. The size distribution of surfactants in the presence of CR is determined by DLS. The CV and LSV measurements were performed in the absence and presence of a varying concentration of surfactants to support the spectral findings. Diffusion coefficient (D) calculated by LSV confirmed the successive interaction between CR and surfactants. Furthermore, the CR-surfactant interaction is also elucidated by the computational simulation using the Gauss View 5.0.9 package to validate the obtained experimental findings.

19.
Colloids Surf B Biointerfaces ; 179: 437-444, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31005003

RESUMO

This work investigates the use of quaternary ammonium based Gemini surfactants (GS) to examine the solubilization and stabilization of a poorly water soluble anti-inflammatory drug Diclofenac (Df). Here we demonstrate the effect of pH on the suspension profile of Df release where it exhibits maximum solubility and absorbance at pH = 10. Interaction process of such cationic GS with Df have been systematically characterized using tensiometry and UV-vis spectroscopy techniques from pre-micellar to post-micellar regions. The spectral results revealed that all the individual GS bind on Df electrostatically resulting in GS + Df complexation. For all the three GS examined, the critical micelle concentration (CMC) was found to decrease in presence of Df following the order: 12-2-12 > 12-2-16 > 16-2-16 which inferred that 12-2-12 can effectively suppress Df degradation at very low concentration. In comparison to 12-2-12, 12-2-16 and 16-2-16 exhibited weaker interaction with Df which limits the stability/solubility of Df in their respective micelles. The aggregation behavior of Df with various GS was investigated by dynamic light scattering (DLS) method. The structural orientation of GS and Df was elucidated by molecular simulation study using Gauss View 5.0.9. The influence of the 12-2-12 in presence of Df on the cervical cell morphology has been undertaken to understand the cytotoxic effect using MTT assay.


Assuntos
Anti-Inflamatórios/farmacologia , Fenômenos Químicos , Simulação por Computador , Tensoativos/química , Água/química , Morte Celular/efeitos dos fármacos , Diclofenaco , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Micelas , Solubilidade , Soluções , Espectrofotometria Ultravioleta , Tensão Superficial
20.
F1000Res ; 8: 1126, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-33093941

RESUMO

A classical ayurvedic polyherbal formulation namely Triphala was assessed for its anti-pathogenic potential against five different pathogenic bacteria. Virulence of four of them towards the model host Caenorhabditis elegans was attenuated (by 18-45%) owing to pre-treatment with Triphala (≤20 µg/ml). Triphala could also exert significant therapeutic effect on worms already infected with Chromobacterium violaceum, Serratia marcescens or Staphylococcus aureus. Prophylactic use of Triphala allowed worms to score 14-41% better survival in face of subsequent pathogen challenge. Repeated exposure to this formulation induced resistance in S. marcescens, but not in P. aeruginosa. It also exerted a post-extract effect (PEE) on three of the test pathogens. Triphala was able to modulate production of quorum sensing (QS)-regulated pigments in three of the multidrug-resistant gram-negative test bacteria. Haemolytic activity of S. aureus was heavily inhibited under the influence of this formulation. P. aeruginosa's lysozyme-susceptibility was found to increase by ~25-43% upon Triphala-pretreatment. These results validate therapeutic potential of one of the most widely used polyherbal ayurvedic formulations called Triphala.


Assuntos
Antibacterianos , Ayurveda , Extratos Vegetais/farmacologia , Animais , Antibacterianos/farmacologia , Caenorhabditis elegans/microbiologia , Chromobacterium/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Percepção de Quorum , Serratia marcescens/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
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