Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Biol Macromol ; 266(Pt 1): 130947, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38521313

RESUMO

Biomaterial-based drug-carrying systems have scored enormous focus in the biomedical sector. Poly(lactic acid) (PLA) is a versatile material in this context. A porous and hydrophilic PLA surface can do this job better. We aimed to synthesize pH-responsive PLA-based porous films for uptaking and releasing amikacin sulfate in the aqueous media. The native PLA lacks functional/polar sites for the said purpose. So, we tended to aminolyze it for tailored physicochemical and surface properties. The amino (-NH2) group density on the treated films was examined using the ninhydrin assay. Electron microscopic analyses indicated the retention of porous morphology after aminolysis. Surface wettability and FTIR results expressed that the resultant films became hydrophilic after aminolysis. The thermal analysis expressed reasonable thermal stability of the aminolyzed films. The prepared films expressed pH-responsive behaviour for loading and releasing amikacin sulfate drug at pH 5.5 and 7.4, respectively. The drug release data best-fitted the first-order kinetic model based on Akaike information and model selection criteria. The prepared PLA-based aminolyzed films qualified as potential candidates for pH-responsive drug delivery applications. This study could be the first report on pH-responsive amikacin sulfate uptake and release on the swellable aminolyzed PLA-based porous films for effective drug delivery application.


Assuntos
Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Poliésteres , Poliésteres/química , Concentração de Íons de Hidrogênio , Porosidade , Preparações de Ação Retardada/química , Portadores de Fármacos/química , Interações Hidrofóbicas e Hidrofílicas
2.
Int J Pharm ; 651: 123789, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38185337

RESUMO

In this study, we present a novel approach for enhancing the performance of Quercetin-loaded nanofiber drug delivery systems through the modification of Polycaprolactone (PCL) solution using Cold Atmospheric Plasma (CAP) prior to electrospinning. CAP treatment was applied to PCL solutions for varying durations, namely, 0.5, 1, and 3 min. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) collectively demonstrate that CAP application and QU loading induce morphological changes in nanofibers, facilitating the creation of drug delivery systems with modified fiber diameters, devoid of bead formation. CAP treatment duration correlates with varying fiber diameters, with the longest treatment (3 min) producing the largest fibers (1324 ± 387 nm). Concurrently, the incorporation of quercetin (QU) into the PCL nanofibers resulted in reduced fiber diameter. These observations emphasize the pivotal role of CAP modification in tailoring nanofiber size and morphology. Notably, minimal peak shifts indicate no significant molecular structure changes in PCL nanofibers compared to PCL solutions, assuring the absence of unwanted chemical modifications or degradation during electrospinning. Furthermore, specific QU peaks are undetectable in Fourier-transform infrared (FTIR) spectra, suggesting dispersed or amorphous QU molecules within the nanofibers. Additionally, X-ray diffraction (XRD) results demonstrate that CAP treatment does not alter the crystalline structure of the PCL nanofiber drug delivery system. Crystalline planes of PCL remain unchanged, affirming stability under CAP treatment conditions. Water contact angles indicate that CAP treatment affects nanofiber hydrophobicity, with shorter CAP treatment times rendering more hydrophilic surfaces. Cumulative QU release percentages vary, with PCL/CAP-0.5-QU exhibiting the highest release at 56 ± 2.2 %, surpassing unmodified PCL/QU. Moreover, cell viability remains comparable or slightly increased when QU is incorporated into CAP-treated PCL nanofibers, suggesting potential mitigation of cytotoxic effects induced by CAP treatment. The combination of QU and CAP treatment enhances cancer cell viability reduction, QU release from nanofibers, and drug loading efficiency in a synergistic manner.


Assuntos
Nanofibras , Gases em Plasma , Quercetina , Nanofibras/química , Sistemas de Liberação de Medicamentos , Poliésteres/química
3.
Int J Biol Macromol ; 253(Pt 5): 127075, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37769768

RESUMO

Micro/nanomotors have emerged as promising platforms for various applications, including drug delivery and controlled release. These tiny machines, built from nanoscale materials such as carbon nanotubes, graphene, metal nanoparticles, or nanowires, can convert different forms of energy into mechanical motion. In the field of medicine, nanomotors offer potential for targeted drug delivery and diagnostic applications, revolutionizing areas such as cancer treatment and lab-on-a-chip devices. One prominent material used in drug delivery is hyaluronic acid (HA), known for its biocompatibility and non-immunogenicity. HA-based drug delivery systems have shown promise in improving the efficacy and reducing the toxicity of chemotherapeutic agents like doxorubicin (DOX). Additionally, micro/nanomotors controlled by external stimuli enable precise drug delivery to specific areas of the body. Cold atmospheric plasma (CAP) has also emerged as a promising technology for drug delivery, utilizing low-temperature plasma to enhance drug release and bioavailability. CAP offers advantages such as localized delivery and compatibility with various drug types. However, further research is needed to optimize CAP drug delivery systems and understand their mechanisms. In this study, gold-hyaluronic acid (Au-HA) micromotors were synthesized for the first time, utilizing acoustic force for self-motion. The release profile of DOX, a widely used anticancer drug, was investigated in pH-dependent conditions, and the effect of CAP on drug release from the micromotors was examined. Following exposure to the CAP jet for 1 min, the micromotors released approximately 29 µg mL-1 of DOX into the PBS (pH 5), which is significantly higher than the 17 µg mL-1 released without CAP. The research aims to minimize side effects, increase drug loading and release efficiency, and highlight the potential of HA-based micromotors in cancer therapy. This study contributes to the advancement of micro-motor technology and provides insights into the utilization of pH and cold plasma technology for enhancing drug delivery systems.


Assuntos
Nanotubos de Carbono , Gases em Plasma , Ouro , Ácido Hialurônico , Sistemas de Liberação de Medicamentos , Doxorrubicina , Liberação Controlada de Fármacos
4.
Int J Biol Macromol ; 235: 123857, 2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-36871685

RESUMO

Polylactic acid (PLA) being a renewable polyester have extensively researched in the biomedical field due to its non-toxicity, high biocompatibility, and easy processing properties. However, low functionalization ability and hydrophobicity limit its applications and hence demands physical and chemical modifications to overcome these limitations. Cold plasma treatment (CPT) is frequently used to improve the hydrophilic properties of PLA-based biomaterials. This provides an advantage to obtain a controlled drug release profile in drug delivery systems. The rapid drug release profile may be advantageous in some applications such as wound application. The main objective of this study is to determine the effects of CPT on PLA or PLA@polyethylene glycol (PLA@PEG) porous films fabricated by solution casting method for use as a drug delivery system with a rapid release profile. The physical, chemical, morphological and drug release properties of PLA and PLA@PEG films, such as surface topography, thickness, porosity, water contact angle (WCA), chemical structure, and streptomycin sulfate release properties, after CPT were systematically investigated. XRD, XPS and FTIR results showed that oxygen-containing functional groups were formed on the film surface with CPT without changing the bulk properties. Along with the changes in the surface morphology such as surface roughness and porosity, the new functional groups provide the films hydrophilic properties by reducing the water contact angle. The improved surface properties enabled the selected model drug, streptomycin sulfate, to exhibit a faster release profile with drug-released mechanism fitted by first order kinetic model. Considering all the results, the prepared films showed an enormous potential for future drug delivery applications, especially in wound application where rapid drug release profile is an advantage.


Assuntos
Gases em Plasma , Polietilenoglicóis/química , Poliésteres/química , Sistemas de Liberação de Medicamentos , Água/química
5.
Int J Pharm ; 590: 119933, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33011251

RESUMO

The design of appropriate materials is required for biomedical applications (e.g. drug delivery systems) in improving people's health care processes. This study focused on the incorporation of nanosized hydroxyapatite (n-HA) with different ratios (ranging from 0.1 wt% to 0.5 wt%) into the poly (ε-caprolactone)/ poly (ethylene oxide) (PCL/PEO) blend matrix loaded or unloaded with curcumin. Composite fibrous material systems were successfully fabricated by the electrospinning technique without the occurrence of bead defects. In addition to the morphological and physicochemical properties of the material systems obtained, the in vitro curcumin release performance was investigated. Further, anti-cancer activity against breast cancer cell line (MCF-7) was examined by MTT assay. Fourier transform infrared spectroscopy and X-ray diffraction characterizations of the fabricated fibrous materials exhibited the interaction of PCL/PEO, n-HA, and curcumin. The 0.3 wt% n-HA incorporated fibrous materials showed a much slower curcumin release manner along with the highest cytotoxicity against MCF-7 cells. The findings obtained from this research are expected to contribute to the appropriate design of nanofiber-based composite materials not only for drug delivery systems but also for the fabrication of biomaterials toward different biomedical applications.


Assuntos
Curcumina , Nanofibras , Biopolímeros , Liberação Controlada de Fármacos , Durapatita , Humanos , Poliésteres , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Int J Pharm ; 568: 118513, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31301462

RESUMO

The fabrication of electrospun composite nanofiber mats used as drug delivery systems with controlled release property is of general interest in biomaterial sciences. The aim of this study was to investigate the effect of MWCNTs on the release profile of the hydrophilic drug. For this aim, tetracycline hydrochloride (TCH) loaded poly (lactic acid) (PLA)/polyvinylpyrrolidone (PVP)/TCH-multiwall carbon nanotubes (MWCNTs) composite fibrous mats were fabricated by electrospinning process, and the drug release profile, release kinetics and cytotoxicity were evaluated to determine the potential for utilization as drug delivery systems. Furthermore, the morphological and physicochemical properties of the composite PLA/PVP/TCH-MWCNTs fibrous mats were characterized. The results demonstrated that TCH and MWCNTs were successfully loaded into the PLA/PVP biopolymeric matrix and the addition of TCH or MWCNTs did not alter the uniform and beadless fibrous structure of the PLA/PVP fibers, resulting in increased Young's modulus and maintained the fibrous structure of the composite mats. Moreover, MWCNTs loaded electrospun mats showed much more controlled drug release manner, increased significantly the drug encapsulation efficiency and reduced the burst release of TCH. In vitro cytotoxicity assay showed that the PLA/PVP/TCH-MWCNTs composite mats did not have a toxic effect on the human umbilical vein endothelial cells (HUVECs). With the improved physicochemical and mechanical properties, controlled drug release-profile and cytocompatibility, the fabricated composite nanofiber mats may be used as therapeutic materials for the biomedical applications as drug delivery systems.


Assuntos
Antibacterianos/química , Nanotubos de Carbono/química , Tetraciclina/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Liberação Controlada de Fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Microscopia Eletrônica de Varredura , Nanotubos de Carbono/ultraestrutura , Poliésteres/química , Povidona/química
7.
Int J Pharm ; 565: 83-94, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31063838

RESUMO

Potential usage of biodegradable and biocompatible polymeric nanofibers is the most attention grabbing topic for the drug delivery system. In order to fabricate ultrafine fibers, electrospinning, one of the well-known techniques, has been extensively studied in the literature. In the present study, the objective is to achieve the optimum blend of hydrophobic and hydrophilic polymers to be used as a drug delivery vehicle and also to obtain the optimum amount of doxycycline (DOXH) to reach the optimum release. In this case, the biodegradable and biocompatible synthetic polymers, poly(ε-caprolactone) (PCL) and poly(ethylene oxide) (PEO), were blended with different ratios for the production of DOXH-loaded electrospun PCL/PEO membranes using electrospinning technique, which is a novel attempt. The fabricated membranes were subsequently characterized to optimize the blending ratio of polymers by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD) and water contact angle analysis. After the characterization studies, different amounts of DOXH were loaded to the optimized blend of PCL and PEO to investigate the release of DOXH from the membrane used as a drug delivery vehicle. In vitro drug release studies were performed, and in vitro drug release kinetics were assessed to confirm the usage of these nanofiber materials as efficient drug delivery vehicles. The results indicated that 3.5% DOXH-loaded (75:25 w/w) PCL/PEO is the most acceptable membrane to provide prolonged release rather than immediate release of DOXH.


Assuntos
Antibacterianos/administração & dosagem , Doxiciclina/administração & dosagem , Membranas Artificiais , Poliésteres/administração & dosagem , Antibacterianos/química , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Doxiciclina/química , Liberação Controlada de Fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Células MCF-7 , Microscopia Eletrônica de Varredura , Nanofibras/administração & dosagem , Nanofibras/química , Nanofibras/ultraestrutura , Poliésteres/química
8.
Med Princ Pract ; 26(1): 50-56, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27780164

RESUMO

OBJECTIVE: To investigate the symptoms of lung cancer in Turkey and to evaluate approaches to alleviate these symptoms. SUBJECTS AND METHODS: This study included 1,245 lung cancer patients from 26 centers in Turkey. Demographic characteristics as well as information regarding the disease and treatments were obtained from medical records and patient interviews. Symptoms were evaluated using the Edmonton Symptom Assessment Scale (ESAS) and were graded on a scale between 0 and 10 points. Data were compared using the χ2, Student t, and Mann-Whitney U tests. Potential predictors of symptoms were analyzed using logistic regression analysis. RESULTS: The most common symptom was tiredness (n = 1,002; 82.1%), followed by dyspnea (n = 845; 69.3%), appetite loss (n = 801; 65.7%), pain (n = 798; 65.4%), drowsiness (n = 742; 60.8%), anxiety (n = 704; 57.7%), depression (n = 623; 51.1%), and nausea (n = 557; 45.5%). Of the 1,245 patients, 590 (48.4%) had difficulty in initiating or maintaining sleep. The symptoms were more severe in stages III and IV. Logistic regression analysis indicated a clear association between demographic characteristics and symptom distress, as well as between symptom distress (except nausea) and well-being. Overall, 804 (65.4%) patients used analgesics, 630 (51.5%) received treatment for dyspnea, 242 (19.8%) used enteral/parenteral nutrition, 132 (10.8%) used appetite stimulants, and 129 (10.6%) used anxiolytics/antidepressants. Of the 799 patients who received analgesics, 173 (21.7%) reported that their symptoms were under control, and also those on other various treatment modalities (dyspnea: 78/627 [12.4%], appetite stimulant: 25/132 [18.9%], and anxiolytics/antidepressants: 25/129 [19.4%]) reported that their symptoms were controlled. CONCLUSION: In this study, the symptoms progressed and became more severe in the advanced stages of lung cancer, and palliative treatment was insufficient in most of the patients in Turkey.


Assuntos
Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/psicologia , Neoplasias de Células Escamosas , Cuidados Paliativos , Adulto , Idoso , Analgésicos/uso terapêutico , Comorbidade , Dispneia/complicações , Dispneia/epidemiologia , Fadiga/complicações , Fadiga/epidemiologia , Feminino , Humanos , Entrevistas como Assunto , Modelos Logísticos , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Dor/complicações , Dor/epidemiologia , Qualidade de Vida , Turquia/epidemiologia
9.
Transplant Proc ; 45(3): 986-92, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23622605

RESUMO

BACKGROUND: Prevention from postoperative pulmonary complications (PPCs) has been an important topic. The aims of this study were to determine the risk factors for PPC after liver surgery and to analyze the efficacy of postoperative pulmonary care on PPC prevention. MATERIALS AND METHODS: We retrospectively analyzed variables of 81 patients who underwent hepatectomy and 4 transplantations between January 2007 and March 2012. RESULTS: Nineteen patients suffered PPCs (22.4%). Bivariate analysis identified four risk factors: preoperative anemia (odds ratio [OR] = 5.69), the American Society of Anesthesiologists (ASA) score of 3 or 4 (OR = 5.36), blood transfusion (OR = 2.81), and prolonged operative time (OR = 1.01). Upon multivariate analysis, only prolonged operative time was an independent risk factor for PPC (OR = 1.01). Pulmonary function test (PFT) was performed for 22 of 41 patients with an ASA score ≥ 2 (53.7%); there was no significant relationship between abnormal PFTs (n = 13) and the development of PPCs (P = .12). CONCLUSIONS: The elimination of risk factors may reduce the incidence of PPCs. Postoperative intensive pulmonary care should be given to all patients after liver surgery but particularly to patients with high ASA scores and those with abnormal PFTs irrespective of age.


Assuntos
Fígado/cirurgia , Pulmão/fisiopatologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos
10.
Fetal Diagn Ther ; 19(3): 246-50, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15067235

RESUMO

We report a case of diprosopus presenting with increased nuchal translucency of 5.3 mm at 14 weeks of gestation. Ultrasonographically, the fetus presented with micrognathia, anterior indentation of the cephalic pole, abnormal cerebral hemispheres with a cystic 4th ventricle and angulation of the spine. The fetal karyotype was normal (46,XX). Following termination of pregnancy, postmortem examination established the diagnosis of diprosopus tetraophthalmus with facial cleft of the 2 faces.


Assuntos
Face/embriologia , Feto/anormalidades , Pescoço/diagnóstico por imagem , Pescoço/embriologia , Gêmeos Unidos , Ultrassonografia Pré-Natal , Aborto Induzido , Adulto , Feminino , Feto/patologia , Humanos , Cariotipagem , Gravidez , Segundo Trimestre da Gravidez , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/embriologia
11.
Hum Reprod ; 14(11): 2822-6, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10548630

RESUMO

Several tests predict ovarian reserve in women undergoing assisted reproductive technologies. However, the accuracy of these tests in assessing the number of the remaining follicles within the ovary (ovarian reserve) has not been previously validated. The aim of this study was to assess the accuracy of ovarian reserve tests, namely basal and clomiphene-stimulated follicle stimulating hormone (FSH) concentrations and gonadotrophin-releasing hormone (GnRH) agonist stimulation test in predicting the number of the follicles within the ovaries. The ovaries of 22 parous women over 35 years of age who underwent oophorectomy were examined histologically for follicle number. Early follicular phase serum FSH, clomiphene citrate challenge tests (CCCT) and GnRH agonist stimulation test (GAST) were performed in the menstrual cycle prior to the surgery. The predictive value of these tests was then assessed. A positive correlation was detected between basal serum oestradiol concentrations and follicles per unit tissue but no significant correlation was detected between basal and clomiphene-stimulated FSH and follicles per unit tissue. The receiver operator characteristic curves indicated that the clomiphene citrate challenge test was the most accurate of the three tests assessed. In conclusion, none of the tests in this study accurately reflects ovarian reserve.


Assuntos
Busserrelina , Clomifeno , Infertilidade Feminina/fisiopatologia , Ovário/fisiopatologia , Adulto , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Fase Folicular , Humanos , Infertilidade Feminina/patologia , Folículo Ovariano/patologia , Curva ROC , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...