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1.
Int J Pharm ; 659: 124287, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38815638

RESUMO

Multifunctional nanoplatforms developed from natural polymers and graphene oxide (GO) with enhanced biological/physicochemical features have recently attracted attention in the biomedical field. Herein, a new multifunctional near-infrared (NIR) light-, pH- and magnetic field-sensitive hybrid nanoplatform (mGO@AL-g-PHPM@ICG/EP) is developed by combining iron oxide decorated graphene oxide nanosheets (mGO) and poly(2-hydroxypropylmethacrylamide) grafted alginate (AL-g-PHPM) copolymer loaded with indocyanine green (ICG) and etoposide (EP) for chemo/phototherapy. The functional groups, specific crystal structure, size, morphology, and thermal stability of the nanoplatform were fully characterized by XRD, UV, FTIR, AFM/TEM/FE-SEM, VSM, DSC/TG, and BET analyses. In this platform, the mGO and ICG, as phototherapeutic agents, demonstrate excellent thermal effects and singlet oxygen production under NIR-light (808 nm) irradiation. The XRD and DSC analysis confirmed the amorphous state of the ICG/EP in the nanoparticles. In vitro photothermal tests proved that the mGO@AL-g-PHPM@ICG/EP nanoparticles had outstanding light stability and photothermal conversion ability. The in vitro release profiles presented NIR light-, pH- and magnetic field-controlled EP/ICG release behaviors. In vitro experiments demonstrated the excellent antitumor activity of the mGO@AL-g-PHPM@ICG/EP against H1299 tumor cells under NIR laser. Benefiting from its low-cost, facile preparation, and good dual-modal therapy, the mGO@AL-g-PHPM@ICG/EP nanoplatform holds great promise in multi-stimuli-sensitive drug delivery and chemo/phototherapy.

2.
Int J Biol Macromol ; 250: 126242, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37562484

RESUMO

Recently, pH-responsive nanogels are playing progressively important roles in cancer treatment. The present study focuses on designing and developing pH-responsive alginate-based nanogels to achieve a controlled release of etoposide (Et) while enhancing its hydrophilicity. Alginate (ALG) is grafted with 2-hydroxypropyl methacrylamide (HPMA) through a microwave-supported method, and the chemical structure of the graft copolymer (ALG-g-PHPMA) was verified by 1H/13C NMR and FTIR techniques. The ALG-g-PHPMA and anticancer drug-loaded ALG-g-PHPMA@Et nanogels were obtained using an emulsion method, and their structures were characterized through FTIR, TG/DSC, AFM/TEM, BET, and DLS analyses. The ALG-g-PHPMA nanogels demonstrated a good drug encapsulation efficiency (79.60 %), displaying a pH-dependent release profile and an in vitro accelerated release of Et compared to the ALG nanogels. Thermal and BET analyses revealed enhanced stability, surface area, and porosity volume of the alginate nanogels. The grafting of PHPMA chains onto alginate altered the surface topology of the ALG nanogels, resulting in lower surface roughness. Furthermore, cytotoxicity tests showed the high biocompatibility of the ALG-g-PHPMA copolymer and its nanogels. The ALG-g-PHPMA@Et nanogels exhibited a higher anticancer effect on lung cancer (H1299) cells than free etoposide. These results suggest that the ALG-g-PHPMA nanogels can be applied as a pH-dependent nanoplatform for delivering anticancer drugs.

3.
Int J Biol Macromol ; 246: 125627, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37406912

RESUMO

The use of natural polymeric nanoparticles (Nps) as drug carriers is a highly promising area of research in the field of drug delivery systems because of their high efficiency. In this study, flurbiprofen (FB) loaded chitosan-graphene oxide (CS-GO) blend Nps were synthesized as a controlled delivery system using the emulsion method. The crystalline, molecular, and morphological structures of the prepared CS-GO Nps were characterized using a variety of analytical methods, including Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-Ray diffractometry (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). It was found that the introduction of GO into the CS nanoparticle formulation increased its thermal stability. The range of the average particle size was between 362 ± 5.06 and 718 ± 2.21 nm, with negative zeta potential values between -7.67 ± 4.16 and - 27.93 ± 2.26 mV. The effects of the CS/GO ratio, the FB/polymer ratio, the amount of span 80, and the cross-linker concentration were assessed on FB release profiles. In vitro release studies displayed a two-stage release behaviour with a fast initial release of the FB, followed by sustained and extended release, and the incorporation of GO into the CS Nps made the FB release more sustained and controlled manner. Besides, the cytotoxicity test of the FB-loaded CS-GO Nps was studied through MTT assay, and it was found that they were biocompatible. Based on these findings, it can be inferred that the prepared CS-GO Nps might be a promising candidate drug carrier system for FB.


Assuntos
Quitosana , Flurbiprofeno , Nanopartículas , Flurbiprofeno/química , Quitosana/química , Espectroscopia de Infravermelho com Transformada de Fourier , Portadores de Fármacos/química , Polímeros , Nanopartículas/química , Tamanho da Partícula
4.
Int J Biol Macromol ; 235: 123888, 2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-36870636

RESUMO

In the last decade, interest in the development of new graft copolymers based on natural polysaccharides has grown remarkably due to their potential applications in the wastewater treatment, biomedical, nanomedicine, and pharmaceutical fields. Herein, a novel graft copolymer of κ-carrageenan with poly(2-hydroxypropylmethacrylamide) (κ-Crg-g-PHPMA) was synthesized using a 'microwave induced' technique. The synthesized novel graft copolymer has been well characterized in terms of FTIR, 13C NMR, molecular weight determination, TG, DSC, XRD, SEM, and elemental analyses, taking κ-carrageenan as a reference. The graft copolymers' swelling characteristics were investigated at pH 1.2 and 7.4. The results of swelling studies displayed that the incorporation of PHPMA groups on κ-Crg provides increasing hydrophilicity. The effect of PHPMA percentage in the graft copolymers and pH of the medium on the swelling percentage was studied and the findings exhibited that swelling ability increased with the increment in PHPMA percentage and pH of the medium. The best swelling percentage was attained at pH = 7.4 and a grafting percentage of 81 % reaching 1007 % at the end of 240 min. Moreover, cytotoxicity of the synthesized κ-Crg-g-PHPMA copolymer was assessed on the L929 fibroblast cell line and obtained to be non-toxic.


Assuntos
Micro-Ondas , Polímeros , Carragenina/química , Polimerização , Polímeros/química , Peso Molecular
5.
J Biomater Sci Polym Ed ; 34(12): 1660-1682, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36756763

RESUMO

In this study, nanoparticles of amoxicillin (AMX) were prepared using chitosan (CHI) and polyethylene glycol (PEG). The physicochemical properties of the particles were investigated by FT-IR, DSC, SEM, and zeta potential analyses. The nanoparticles showed a spherical shape, and the average size of formulations was within the range of 696.20 ± 24.86 - 359.53 ± 7.41 nm. Zeta potential data demonstrated that the formulations had positive surface charges with a zeta potential range of 21.38 ± 2.28 - 7.73 ± 1.66 mV. FTIR analysis showed that the drug was successfully entrapped in the nanoparticles. DSC results suggested that the drug was present in amorphous form in the polymer matrix. In vitro release studies demonstrated that the release pattern consisted of two phases, with an initial burst release followed by a controlled and sustained release. The MTT assay results on mouse fibroblast cell line indicated that the prepared formulations did not affect the viability of the cells. In the in vitro antibacterial activity test, it was found that the drug-loaded nanoparticles have AMX-equivalent antibacterial activity against E. coli, and S. aureus. These findings revealed that the obtained nanoparticles might be a promising and safe nanocarrier system for efficient delivery of AMX.


Amoxicillin has been encapsulated in PEG-CHI nanoparticles.The structure of nanoparticles was investigated by SEM, FTIR, and DSC studies.The nanoparticles showed an initial fast release followed by a slow release.PEG-CHI nanoparticles displayed equivalent antibacterial activity to amoxicillin, and a non-cytotoxic profile in healthy cells.


Assuntos
Antineoplásicos , Quitosana , Nanopartículas , Animais , Camundongos , Amoxicilina/farmacologia , Polietilenoglicóis/química , Quitosana/química , Staphylococcus aureus , Escherichia coli , Espectroscopia de Infravermelho com Transformada de Fourier , Sistemas de Liberação de Medicamentos/métodos , Antibacterianos/farmacologia , Antibacterianos/química , Nanopartículas/química , Portadores de Fármacos/química , Tamanho da Partícula
6.
Int J Biol Macromol ; 192: 701-715, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637816

RESUMO

In the last two decades, the utilization of magnetic nanospheres in intelligent polymeric structures have received increased attention of researchers in numerous biomedical applications. Here, hybrid nanostructured triple-responsive magnetic nanospheres (κ-Car-g-P(AA/DMA)@Fe3O4) containing inorganic iron oxide core (Fe3O4) and organic graft copolymeric shell based on κ-carrageenan (κ-Car) and poly(acrylic acid/dimethylaminoethyl methacrylate) (P(AA/DMA)) were synthesized by microwave induced co-precipitation technique. The structure, size, surface morphology, magnetic property and stability of synthesized κ-Car-g-P(AA/DMA)@Fe3O4 magnetic nanospheres were characterized using FTIR, UV, XRD, TEM, Zeta-sizer, and VSM. κ-Car-g-P(AA/DMA)@Fe3O4 nanospheres were loaded with 5-Fluorouracil (5-FU) as an antineoplastic drug, and their 5-FU release behavior was explored in diverse graft yields, pH values, temperatures and in the existence of an alternating magnetic field. The κ-Car-g-P(AA/DMA)@Fe3O4 nanospheres demonstrated pH-, thermo-, and magnetic field-responsive 5-FU release with good biocompatibility and excellent anticancer activity. In addition, 5-FU release under 50 mT magnetic field reached to 100% within 4 h. This work exhibits that hybrid nanospheres have a triple stimuli-responsive influence, which is of principal importance for the future design and application of multi-functional responsive platforms to develop externally stimulated release of active agents and their healthcare capability.


Assuntos
Carragenina/química , Preparações de Ação Retardada/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Nanosferas/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Sobrevivência Celular/efeitos dos fármacos , Fenômenos Químicos , Portadores de Fármacos/síntese química , Liberação Controlada de Fármacos , Fluoruracila/administração & dosagem , Fluoruracila/química , Humanos , Concentração de Íons de Hidrogênio , Nanopartículas Magnéticas de Óxido de Ferro/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Difração de Raios X
7.
Toxicol Lett ; 348: 1-9, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33984417

RESUMO

Nanotechnology-based drugs show superiority over conventional medicines because of increased bioavailability, lower accumulation in non-target tissues, and improved therapeutic index with increased accumulation at target sites. However, it is important to be aware of possible problems related to the toxicity of these products, which have therapeutically superior properties. Accordingly, the present study was designed to investigate the safety profile of amoxicillin nanoparticles (AmxNPs) that we developed to increase the oral bioavailability of amoxicillin (Amx) in poultry. In the first part of the study, the genotoxicity potential of AmxNPs was evaluated using the Ames test and the in vitro comet assay. The results of Ames test showed that none of the tested concentrations of Amx and AmxNPs cause a significant increase in the revertant number of Salmonella typhimurium strains TA98, and TA100, either with or without metabolic activation. Similarly, the comet assay revealed that AmxNPs did not induce DNA damage at any of the concentrations used, whereas high-dose (200 µg/mL) of Amx caused a significant increase in the percentage of DNA in the tail. In the second part of the study, the toxicity potential of AmxNPs on broilers was investigated by measuring biochemical parameters. In vivo results demonstrated that AmxNps did not cause a significant change in biochemical parameters, whereas Amx increased ALT, glucose, and cholesterol levels at certain sampling times. The obtained findings suggest that AmxNPs could be a safe promising potential drug in drug delivery systems.


Assuntos
Amoxicilina/toxicidade , Nanopartículas/toxicidade , Animais , Galinhas , Ensaio Cometa , Dano ao DNA , Sistemas de Liberação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Camundongos , Polímeros , Salmonella typhimurium/efeitos dos fármacos , Células Swiss 3T3
8.
Int J Biol Macromol ; 164: 4499-4515, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32898537

RESUMO

Herein, thermo- and pH-sensitive pectin-graft-poly(dimethylaminoethyl methacrylate) copolymer-coated magnetic nanoparticles were synthesized via a green and rapid synthetic approach based on microwave irradiation. Firstly, a novel thermo- and pH-sensitive pectin-graft-poly(dimethylaminoethyl methacrylate) copolymer (Pec-g-PolyDMAEMA) was synthesized and then, Pec-g-PolyDMAEMA based magnetic nanoparticles (Pec-g-PolyDMAEMA@Fe3O4) were produced via microwave-assisted co-precipitation method. The thermo/pH/magnetic field multi-sensitive hybrid nanoparticle was characterized by techniques like TEM, VSM, FT-IR, and TGA/DSC. In vitro release studies of 5-Fluorouracil (FL) were carried out by altering the temperature (37 and 44°C), pH (5.5 and 7.4) and presence of an AMF. The FL release of Pec-g-PolyDMAEMA@Fe3O4@FL exhibited pH-sensitive behavior. They showed thermo/pH-sensitive FL release features with the greatest release of FL at 37°C (56%) than at 44°C (40%) and at pH of 7.4 (63%) than at pH of 5.5 (45%) within 48h. The FL release was also significantly increased (100%) with the presence of a 50 mT magnetic field. These results indicate that the developed Pec-g-PolyDMAEMA@Fe3O4 nanoparticles are promising in the application of multi-stimuli-sensitive delivery of drugs.


Assuntos
Materiais Revestidos Biocompatíveis , Portadores de Fármacos , Nanopartículas de Magnetita , Metacrilatos/química , Pectinas/química , Ácidos Polimetacrílicos/química , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/farmacologia , Antimetabólitos Antineoplásicos/toxicidade , Materiais Revestidos Biocompatíveis/farmacologia , Materiais Revestidos Biocompatíveis/toxicidade , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Fibroblastos/efeitos dos fármacos , Fluoruracila/administração & dosagem , Fluoruracila/farmacologia , Fluoruracila/toxicidade , Humanos , Concentração de Íons de Hidrogênio , Células MCF-7 , Campos Magnéticos , Nanopartículas de Magnetita/administração & dosagem , Nanopartículas de Magnetita/toxicidade , Camundongos , Transição de Fase , Ácidos Polimetacrílicos/síntese química , Ácidos Polimetacrílicos/farmacologia , Ácidos Polimetacrílicos/toxicidade , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
9.
Int J Biol Macromol ; 159: 751-762, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32416307

RESUMO

In present work, temperature-responsive flurbiprofen (FLU) containing chitosan/hydroxypropyl cellulose (CS/HPC) blend nanospheres were prepared using emulsion method. The structures of blend nanospheres were characterized by ATR-FTIR, XRD, SEM, DSC/TGA, zeta potential and particle size analyses. Their lower critical solution temperatures (LCST) were determined and found to be 42 °C. In vitro release studies were performed in gastrointestinal-tract simulated conditions at 30 °C, 37 °C and 44 °C. As the medium temperature was increased, the release of FLU decreased, indicating that blend nanospheres had temperature-responsive feature. The FLU release demonstrated that release profiles depend upon CS/HPC ratio, amount of FLU present in the nanospheres and percentage of cross-linker used. Moreover, the cytotoxicity tests were performed via MTT method and it was observed CS/HPC nanospheres were biocompatible. Based on the in vitro release profile and cytotoxicity studies, the fabricated CS/HPC blend nanospheres could be a promising candidate as a temperature-responsive nano-carrier for controlled drug release.


Assuntos
Celulose/análogos & derivados , Quitosana/química , Preparações de Ação Retardada , Portadores de Fármacos/química , Desenho de Fármacos , Flurbiprofeno/administração & dosagem , Nanosferas/química , Anti-Inflamatórios não Esteroides/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Celulose/química , Liberação Controlada de Fármacos , Cinética , Nanosferas/ultraestrutura , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Difração de Raios X
10.
Int J Biol Macromol ; 152: 359-370, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32061853

RESUMO

A binary graft copolymerization of dimethylaminoethyl methacrylate (DMAEMA) and acrylic acid (AA) onto κ-carrageenan (CG) was performed by using microwave irradiation in the presence of 4,4'-Azobis(4-cyanovaleric acid) (ACVA). The structure of the CG-g-P(DMAEMA/AA) copolymers was confirmed using 13C NMR, FTIR, DSC/TGA and XRD. The effects of the DMAEMA/AA ratio, the microwave power and irradiation duration, and the concentrations of CG and ACVA on grafting yield and grafting efficiency were all investigated, and the best values of them were found to be 150% and 85%, respectively. The lower critical solution temperatures (LCST) for CG-g-P(DMAEMA/AA) copolymers at various pH conditions were determined, and when the pH value of the medium was increased from 1.2 to 10, the LCST of the copolymer decreased from 53 °C to 39 °C. Moreover, swelling performance of the copolymers under various pH conditions was examined, and it was observed that the swelling ratio of the copolymer increased with a decrease in the pH value of the medium.


Assuntos
Carragenina/química , Polímeros/química , Acrilatos/química , Concentração de Íons de Hidrogênio , Metacrilatos/química , Micro-Ondas , Polimerização , Temperatura
11.
Carbohydr Polym ; 218: 112-125, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31221312

RESUMO

Pectin based micro/nanocarriers display promising properties for biomedical applications. In this study, thermo/pH-responsive chitosan coated pectin-graft-poly(N,N-diethyl acrylamide) (Pec-g-PDEAAm/CS) microcarriers containing 5-Fluorouracil (5-FU) as a model drug were developed. The structure, thermal stability and surface morphology of 5-FU-loaded microcarriers were investigated using FTIR, XRD, DSC and SEM. Microcarrier formulations were fabricated by varying grafting yield, drug/copolymer ratio, chitosan, and crosslinking agent concentrations. The effect of these parameters on swelling degree and 5-FU release was explored. It was observed that the grafting of pectin with poly(N,N-diethyl acrylamide) ensured sustained/controlled and thermo/pH responsive release of 5-FU. Besides, in vitro cytotoxicity results displayed that Pec-g-PDEAAm/CS microcarriers had good biocompatibility. Results illustrated that 5-FU release and swelling degree of the microcarriers were greatly controlled by especially chitosan shell, 5-FU/copolymer ratio and crosslink density. Therefore, based on the findings the developed thermo/pH-responsive Pec-g-PDEAAm/CS microcarriers might be considered as a promising carrier for controlled drug delivery.

12.
Artif Cells Nanomed Biotechnol ; 46(sup2): 964-973, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29806495

RESUMO

In this study, amoxicillin (AMO)-loaded poly(vinyl alcohol)/sodium alginate (PVA/NaAlg) nanoparticles were prepared as a polymer-based controlled release system. The physicochemical properties of the obtained nanoparticles were investigated by XRD, DSC/TGA, particle size analyses and zeta potential measurements. The average particle sizes were in the range from 336.3 ± 25.66 to 558.3 ± 31.39 nm with negative zeta potential values from -41.86 ± 0.55 to -47.3 ± 2.76 mV. The influences of PVA/NaAlg ratio, span 80 concentration, exposure time to glutaraldehyde (GA) and the drug/polymer ratio on AMO release profiles were evaluated. In vitro drug release studies showed a controlled and pH dependent AMO release with an initial burst effect. XRD patterns and DSC thermograms of AMO-loaded nanoparticles revealed that the drug in the nanoparticles was in amorphous form, which was more stable than the crystalline form. The antibacterial activity of the optimal formulation was also investigated. The minimum inhibitory concentration (MIC) values of this formulation had the comparable antibacterial activity with that of pure AMO. These results indicate that the developed nanoparticles could be a promising candidate drug delivery system for AMO.


Assuntos
Amoxicilina/química , Amoxicilina/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Nanopartículas/química , Álcool de Polivinil/química , Alginatos/química , Preparações de Ação Retardada , Escherichia coli/efeitos dos fármacos , Cinética , Tamanho da Partícula , Staphylococcus aureus/efeitos dos fármacos
13.
Int J Biol Macromol ; 113: 669-680, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29499266

RESUMO

The functionalization of polysaccharides with synthetic polymers has attracted great attention owing to its application in many industrial fields. The aim of this work was to study the impact of pectin functionalization with N,N-diethylacrylamide (DEAAm). Pectin was modified via microwave-induced graft copolymerization of DEAAm using ceric ammonium nitrate (CAN) and N,N,N',N'-tetramethylethylenediamine (TEMED). FTIR, 13C NMR, DSC/TGA, XRD, and SEM techniques were used to verify the structure of graft copolymers. Various reaction conditions such as microwave irradiation time, temperature, microwave power, monomer, initiator, and TEMED concentrations were investigated to get a maximum grafting yield of 192%. Lower critical solution temperatures (LCST) of graft copolymers were determined by UV spectroscopy. Graft copolymers were found to be thermo-sensitive, with LCST of 31°C and high thermal resistance. Biocompatibility test of copolymers showed that copolymers were not cytotoxic to L929 fibroblasts cells and can be used as a biomaterial.


Assuntos
Acrilamidas/química , Acrilamidas/síntese química , Micro-Ondas , Pectinas/química , Polímeros/química , Polímeros/síntese química , Temperatura , Cério/química , Técnicas de Química Sintética , Etilenodiaminas/química , Polimerização
14.
Artif Cells Nanomed Biotechnol ; 46(sup1): 264-273, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29298530

RESUMO

Recent studies have shown that graphene oxide (GO) drug carrier functionalized with biocompatible natural polymers lead to higher loading efficacy and better stability with diminished cellular toxicity. Pectin (PEC) is one of the polysaccharide natural polymers, which has the potential to be used for drug delivery. In this work, we have successfully developed a novel PEC-conjugated magnetic GO nanocarrier for effective delivery of paclitaxel. The structure, surface morphology and thermal stability of the nanohybrid were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and zeta-sizer. Moreover, drug loading and release performance were studied by UV-vis absorption spectra. The cytotoxicity test was also performed by MTT test using L-929 fibroblast normal cell and MCF-7 cancer lines. The prepared nanocarrier showed an improved stability with enhanced drug loading capacity. Additionally, pH-responsive release analysis of the nanohybrid illustrated higher drug release at endosomal pH of cancer cell than that of normal physiological environment. Besides, cytotoxicity test demonstrated the synthesized nanohybrid is biocompatible, having very high relative cell viability. Bearing in mind these findings, the designed multifunctional nanohybrid drug carrier will be a good candidate for cancer drug delivery.


Assuntos
Portadores de Fármacos/química , Grafite/química , Imãs/química , Nanopartículas/química , Óxidos/química , Paclitaxel/química , Pectinas/química , Liberação Controlada de Fármacos , Humanos , Células MCF-7 , Paclitaxel/farmacologia , Tamanho da Partícula
15.
RSC Adv ; 6(36): 30285-30292, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27774142

RESUMO

Aptamer-functionalized magnetic graphene oxide conjugates loaded with indocyanine green (ICG) dye, or Apt@ICG@mGO, have been successfully developed for dual-targeted photothermal and photodynamic therapy. In general, a drug or its carrier or their dosage can be imprtant important issues in terms of toxicity. However, in this system, each component used is quite safe, biocompatibe and clean. For instance, ICG, a Food and Drug Administration (FDA) approved near-infrared (NIR) dye, serves as both a photothermal and photodynamic agent. It is immobilized on the surface of mGO via a physical interaction called "π-π stacking". The mGO, as a most biocomptible member of the carbo family, is selected for use as a platform for aptamer and ICG dye conjugation, as well as as a photothermal agent. The light in the near-infrared region (NIR) was chosen as a harmless light source for activating the agents for photothermal therapy (PTT) and photodynamic therapy (PDT). The magnetic properties of mGO are also used for separation of Apt@ICG@mGO conjugates from the reaction medium. Aptamer sgc8 acts as a targeting ligand to selectively and specifically bind to a protein on the membrane of cancer cell line CCRF-CEM. After the aptamer- functionalized ICG@mGO conjugates are incubated with target CEM cells at 37 °C for 2 hours, they are bound to cells or they may be internalized into the cell via endocytosis. More significantly, we demonstrated that the Apt@ICG@mGO conjugates produce heat for photothermal therapy (PTT) and singlet oxygen for photodynamic therapy (PDT) upon NIR laser irradiation at 808 nm. Thus, remarkably efficient cancer cell destructions with ~41% and ~60% and ~82% cell killing using 10, 50 and 100 ppm Apt@ICG@mGO, respectively are achieved in 5 min light exposure.

16.
Int J Biol Macromol ; 82: 530-40, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26549441

RESUMO

Modification of sodium alginate (NaAlg) was carried out using N,N'-dimethylacrylamide (DMAAm) as a monomer and azobisizobutyronitrile (AIBN) as an initiator under microwave irradiation. The effect of reaction conditions such as concentrations of DMAAm, AIBN, NaAlg as well as microwave power and temperature on grafting and grafting efficiency has been explored. Maximum grafting and grafting efficiency has been observed at 1h of grafting time, 0.291 M of DMAAm concentration, 500 W microwave irradiation power, 0.134 M of AIBN concentration, 75°C of reaction temperature and 0.5 g/dL of NaAlg concentration. The grafted copolymer has been characterized by FTIR, DSC, TGA, (13)C NMR, XRD, SEM, and GPC analysis. Cytotoxicity as standard MTT assay, apoptotic and necrotic effects of graft copolymer were investigated on L929 fibroblast cell. It has been found that the grafted copolymer is biocompatible and thermally more stable than the ungrafted alginate.


Assuntos
Acrilamidas/química , Alginatos/química , Micro-Ondas , Polímeros/química , Varredura Diferencial de Calorimetria , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Espectroscopia de Ressonância Magnética , Peso Molecular , Nitrilas/química , Polímeros/síntese química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Difração de Raios X
17.
Eur J Pharm Biopharm ; 82(2): 316-31, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22906708

RESUMO

The first decade of the 21st century saw an increasing interest in the development of devices and biomaterials for delivery of bioactive substances that can be controlled by external stimuli. This study deals with the production of novel pH and temperature responsive beads for colon-specific delivery of indomethacine (IM). For this purpose, N-isopropylacrylamide (NIPAAm) was grafted onto sodium alginate (NaAlg) with microwave radiation in aqueous solution. The graft copolymer (NaAlg-g-PNIPAAm) was characterized by using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), elemental analysis, differential scanning calorimetry (DSC), and thermogravimetric analysis. A series of pH- and temperature-responsive NaAlg-g-PNIPAAm beads were prepared as drug delivery matrices of indomethacine cross-linked by glutaraldehyde (GA) in the hydrochloric acid catalyst. Preparation condition of the beads was optimized by considering the percentage entrapment efficiency, particle size, swelling capacity of beads, and their release data. Effects of variables such as graft yield, drug/polymer ratio, exposure time to GA, and concentration of GA on the release of IM were investigated and discussed at two different pH values (1.2 and 7.4) and temperatures (25°C and 37°C). It was observed that IM release from the beads decreased when the grafting of NIPAAm, drug/polymer ratio (d/p), and extent of cross-linking were increased. The results also showed that NaAlg-g-PIPAAm beads were positive pH and temperature responsive. The release of IM from grafted beads was slower for the pH 1.2 solution than that of the pH 7.4 buffer solution, whereas the release rate was higher at 37°C than at 25°C.


Assuntos
Acrilamidas/química , Alginatos/química , Micro-Ondas , Polímeros/química , Resinas Acrílicas , Sistemas de Liberação de Medicamentos/métodos , Ácido Glucurônico/química , Glutaral/química , Ácidos Hexurônicos/química , Ácido Clorídrico/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Concentração de Íons de Hidrogênio , Imidazóis/química , Indometacina/análogos & derivados , Indometacina/química , Cinética , Tamanho da Partícula , Transição de Fase , Soluções/química , Temperatura
18.
Eur J Pharm Biopharm ; 65(2): 204-14, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16996255

RESUMO

In this study, acrylamide (AAm) was grafted onto poly(vinyl alcohol) (PVA) with UV radiation at ambient temperature. The graft copolymer (PVA-g-PAAm) was characterized by using Fourier transform infrared spectroscopy (FTIR), elemental analysis and differential scanning calorimetry (DSC). Polymeric blend beads of PVA-g-PAAm and PVA with sodium alginate (NaAlg) were prepared by cross-linking with glutaraldehyde (GA) and used to deliver a model anti-inflammatory drug, diclofenac sodium (DS). Preparation condition of the beads was optimized by considering the percentage entrapment efficiency, particle size, swelling capacity of beads and their release data. Effects of variables such as PVA/NaAlg ratio, acrylamide content, exposure time to GA and drug/polymer ratio on the release of DS were discussed at three different pH values (1.2, 6.8, 7.4). It was observed that, DS release from the beads decreased with increasing PVA/NaAlg (m/m) ratio, drug/polymer ratio (d/p) and extent of cross-linking. However, DS release increased with increasing acrylamide content of the PVA-g-PAAm polymer. The highest DS release was obtained to be 92% for 1/1 PVA-g-PAAm/NaAlg ratio beads. It was also observed from release results that DS release from the beads through the external medium is much higher at high pH (6.8 and 7.4) than that at low pH (1.2). The drug release from the beads mostly followed Case II transport.


Assuntos
Resinas Acrílicas/química , Alginatos/química , Diclofenaco/administração & dosagem , Diclofenaco/química , Álcool de Polivinil/química , Acrilamidas/química , Algoritmos , Varredura Diferencial de Calorimetria , Química Farmacêutica , Reagentes de Ligações Cruzadas , Excipientes , Ácido Glucurônico/química , Glutaral , Ácidos Hexurônicos/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Peso Molecular , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Viscosidade
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