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1.
Biomacromolecules ; 20(2): 693-704, 2019 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-30358992

RESUMO

Brittleness has hindered commercialization of cellulose nanofibril (CNF) films. The use of synthetic polymers and plasticizers is a known detour that impairs biodegradability and carbon footprint of the product. Herein, we utilize a variety of softwood Kraft lignin morphologies to obtain strong and ductile CNF nanocomposite films. An optimum 10 wt % content of colloidal lignin particles (CLPs) produced films with nearly double the toughness compared to a CNF film without lignin. CLPs rendered the films waterproof, provided antioxidant activity and UV-shielding with better visible light transmittance than obtained with irregular lignin aggregates. We conclude based on electron microscopy, dynamic water sorption analysis, and tp-DSC that homogeneously distributed CLPs act as ball bearing lubricating and stress transferring agents in the CNF matrix. Overall, our results open new avenues for the utilization of lignin nanoparticles in biopolymer composites equipped with versatile functionalities for applications in food packaging, water purification, and biomedicine.


Assuntos
Lignina/química , Nanocompostos/química , Nanofibras/química , Coloides/química , Nanocompostos/efeitos da radiação , Nanofibras/efeitos da radiação , Luz Solar , Resistência à Tração , Raios Ultravioleta
2.
J Microencapsul ; 34(4): 408-415, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28590788

RESUMO

We prepared and characterised thermo-responsive magnetic liposomes, which were designed to combine features of magnetic targeting and thermo-responsive control release for hyperthermia-triggered local drug delivery. The particle size and zeta-potential of the thermo-responsive magnetic ammonium bicarbonate (MagABC) liposomes were about 210 nm and -14 mV, respectively. The MagABC liposomes showed encapsulation efficiencies of about 15% and 82% for magnetic nanoparticles (mean crystallite size 12 nm) and doxorubicin (DOX), respectively. The morphology of the MagABC liposomes was visualised using transmission electron microscope (TEM). The MagABC liposomes showed desired thermo-responsive release. The MagABC liposomes, when physically targeted to tumour cells in culture by a permanent magnetic field yielded a substantial increase in intracellular accumulation of DOX as compared to non-magnetic ammonium bicarbonate (ABC) liposomes. This resulted in a parallel increase in cytotoxicity for DOX loaded MagABC liposomes over DOX loaded ABC liposomes in tumour cells.


Assuntos
Portadores de Fármacos/química , Hipertermia Induzida , Lipossomos/química , Nanopartículas de Magnetita/química , Antibióticos Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Compostos Ferrosos/química , Células HeLa , Humanos , Temperatura
3.
Biomacromolecules ; 16(10): 3265-74, 2015 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-26388179

RESUMO

Biocompatible amphiphilic block copolymers composed of polysarcosine (PSar) and poly(ε-caprolactone) (PCL) were synthesized using ring-opening polymerization of sarcosine N-thiocarboxyanhydride initiated by oxyamine-ended PCL and characterized by NMR, SEC, and DSC. Self-assembling of two triblock copolymers PSar8-b-PCL28-b-PSar8 (CS7) and PSar16-b-PCL40-b-PSar16 (CS10) in dilute solution was studied in detail toward polymersome formation using thin-film hydration and nanoprecipitation techniques. A few giant vesicles were obtained by thin-film hydration from both copolymers and visualized by confocal laser scanning microscope. Unilamellar sheets and nanofibers (with 8-10 nm thickness or diameter) were obtained by nanoprecipitation at room temperature and observed by Cryo-TEM. These lamellae and fibrous structures were transformed into worm-like cylinders and spheres (D∼30-100 nm) after heating to 65 °C (>Tm,PCL). Heating CS10 suspensions to 90 °C led eventually to multilamellar polymersomes (D∼100-500 nm). Mechanism II, where micelles expand to vesicles through water diffusion and hydrophilic core forming, was proposed for polymersome formation. A cell viability test confirmed the self-assemblies were not cytotoxic.


Assuntos
Microscopia Crioeletrônica/métodos , Peptídeos/química , Poliésteres/química , Sarcosina/análogos & derivados , Varredura Diferencial de Calorimetria , Polimerização , Sarcosina/química
4.
Mol Pharm ; 10(5): 2062-70, 2013 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-23557122

RESUMO

A novel drug delivery system, TPGS 1000 (TPGS) emulsified zein nanoparticles (TZN), were designed with an objective to improve the oral bioavailability of daidzin, an isoflavone glycoside with estrogenic activities. Zein nanoparticles (ZN) and TZN were fabricated using an antisolvent method. They were found to be spherical in shape with a mean size around 200 nm and a low polydispersity. Their zeta potentials were about +25 mV at pH 5.5 and -23 mV at pH 7.4. Adding TPGS as an emulsifier increased the encapsulation efficiency of daidzin in ZN from 53% to 63%. Daidzin loaded TZN had a slower daidzin release compared with daidzin loaded ZN in both simulated digestive fluids and a pH 7.4 buffer. Confocal laser scanning microscopy suggested that the cellular uptake of coumarin-6 labeled TZN in human intestinal epithelial Caco-2 cells were significantly higher than fluorescent ZN. Cellular uptake and transport studies revealed that daidzin in TZN were taken up more efficiently into Caco-2 cells and transported more quickly through Caco-2 monolayer than daidzin solution. A pharmacokinetic study demonstrated that the Cmax of daidzein in mice after oral administration of daidzin loaded TZN was 5.66 ± 0.16 µM, which was improved by 2.64-fold compared with that of daidzin solution (2.14 ± 0.04 µM). Moreover, the areas under the curve (AUC0-12 h) for daidzin loaded in TZN were enhanced by 2.4-fold compared with that of daidzin solution. These results suggested that TZN could be an effective strategy to improve the oral bioavailability of isoflavone glycosides like daidzin.


Assuntos
Isoflavonas/administração & dosagem , Isoflavonas/farmacocinética , Vitamina E/análogos & derivados , Zeína/química , Administração Oral , Animais , Disponibilidade Biológica , Transporte Biológico Ativo , Células CACO-2 , Cumarínicos/administração & dosagem , Cumarínicos/farmacocinética , Sistemas de Liberação de Medicamentos , Emulsões , Humanos , Absorção Intestinal , Masculino , Camundongos , Nanopartículas/química , Nanopartículas/ultraestrutura , Fitoestrógenos/administração & dosagem , Fitoestrógenos/farmacocinética , Polietilenoglicóis/química , Soluções , Tiazóis/administração & dosagem , Tiazóis/farmacocinética , Vitamina E/química
5.
Int J Biol Macromol ; 242(Pt 3): 124990, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37211070

RESUMO

Recently, increasing attention has been paid to natural polysaccharides for their low cost, biocompatibility and biodegradability. Quaternization is a modification method to improve the solubility and antibacterial ability of natural polysaccharides. Water-soluble derivatives of cellulose, chitin and chitosan offer the prospect of diverse applications in a wide range of fields, such as antibacterial products, drug delivery, wound healing, sewage treatment and ion exchange membranes. By combining the inherent properties of cellulose, chitin and chitosan with the inherent properties of the quaternary ammonium groups, new products with multiple functions and properties can be obtained. In this review, we summarized the research progress in the applications of quaternized cellulose, chitin and chitosan in recent five years. Moreover, ubiquitous challenges and personal perspectives on the further development of this promising field are also discussed.


Assuntos
Quitosana , Quitina , Celulose , Polissacarídeos , Antibacterianos/farmacologia
6.
Colloids Surf B Biointerfaces ; 216: 112557, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35576882

RESUMO

Dual/Multi-modal photonanomedicines with the maximized antitumor efficacy has attracted extensive concerning. In this contribution, through photovoltaic engineering of photothermal conjugated polymer, a facile magnetic-targeted capacitive heterostructure of polypyrrole (upconversion nanoparticles (UCNPs)@SiO2-Fe3O4 @polypyrrole (USFP)), capable of photodynamic therapy (PDT) and photothermal therapy (PTT) upon near infrared (NIR) excitation is purposefully developed. Owing to the optimized regulation of photoreaction pathway via photoinduced capacitance effect, the yield of reactive oxygen species (ROS) including 1O2 in polypyrrole can be significantly promoted. Notably, the external layers (porous silica and polypyrrole) of USFP allow the encounter and subsequent Fenton reaction between Fe3O4 and H2O2 in tumor site, thereby further enhancing the photodynamic effect via an effective O2 supply. Upon intravenous injection into tumor-bearing mice, USFP can accumulate in tumors through a magnetic guidance, ablation experiments in vitro and in vivo confirmed the enhanced synergistic therapeutic effect and desirable biocompatibility of USFP.


Assuntos
Nanopartículas , Neoplasias , Fotoquimioterapia , Animais , Linhagem Celular Tumoral , Peróxido de Hidrogênio , Hipóxia/terapia , Fenômenos Magnéticos , Camundongos , Camundongos Nus , Nanopartículas/química , Neoplasias/tratamento farmacológico , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Terapia Fototérmica , Polímeros/química , Pirróis/química , Pirróis/farmacologia , Dióxido de Silício
7.
J Mater Chem B ; 10(27): 5154-5164, 2022 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-35666635

RESUMO

Tumor-triggered targeting ammonium bicarbonate (TTABC) liposomes were proposed to improve the uptake of ammonium bicarbonate (ABC) liposomes in tumor cells and retain their long circulation in vivo in our previous study. However, it must be solved how to precisely release the loaded drugs of the TTABC liposomes into tumor cells. In addition, synergistic multimodal therapy could result in better tumor treatment outcomes than monomodal chemotherapy. In the research, we prepared indocyanine green (ICG) and doxorubicin (DOX) encapsulated TTABC liposomes (ICG&DOX@TTABC) to achieve near-infrared (NIR) light-controlled chemo/photothermal/photodynamic multimodal therapy guided by fluorescence and photothermal imaging. In vitro and vivo studies show that ICG&DOX@TTABC can specifically accumulate in tumor tissues, effectively transform NIR light into local thermo-therapy, and have excellent anti-tumor ability without obvious side effects. ICG&DOX@TTABC could be promising for fluorescence and photothermal imaging-guided chemo/photothermal/photodynamic tumor treatment.


Assuntos
Lipossomos , Neoplasias , Bicarbonatos , Terapia Combinada , Doxorrubicina , Humanos , Verde de Indocianina/farmacologia , Verde de Indocianina/uso terapêutico , Lipossomos/uso terapêutico , Neoplasias/tratamento farmacológico , Fototerapia/métodos
8.
Environ Pollut ; 304: 119159, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35304177

RESUMO

Plastic pollution, particularly non-degradable residual plastic films and microplastics (MPs), is a serious environmental problem that continues to worsen each year. Numerous studies have characterized the degradation of plastic fragments; however, there is known a lack of about the state of current physicochemical biodegradation methods used for plastics treatment and their degradation efficiency. Therefore, this review explores the effects of different physicochemical factors on plastics/MPs degradation, including mechanical comminution, ultraviolet radiation, high temperature, and pH value. Further, this review discusses different mechanisms of physicochemical degradation and summarizes the degradation efficiency of these factors under various conditions. Additionally, the important role of enzymes in the biodegradation mechanism of plastics/MPs is also discussed. Collectively, the topics discussed in this review provide a solid basis for future research on plastics/MPs degradation methods and their effects.


Assuntos
Microplásticos , Poluentes Químicos da Água , Biodegradação Ambiental , Monitoramento Ambiental , Plásticos , Raios Ultravioleta , Poluentes Químicos da Água/análise
9.
ACS Appl Mater Interfaces ; 13(29): 34793-34806, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34261310

RESUMO

There is a need for safe and sustainable alternatives in the coating industry. Bio-based coatings are interesting in this perspective. Although various oils and waxes have been used as traditional wood coatings, they often lack sufficient durability. Lignin is an abundant natural polyphenol that can be used to cure epoxies, but its poor water solubility has impeded the use of unmodified lignin in coatings in the past. To address this issue, water-dispersible colloidal lignin particles (CLPs) and an epoxy compound, glycerol diglycidyl ether (GDE), were used to prepare multiprotective bio-based surface coatings. With the GDE/CLP ratios of 0.65 and 0.52 g/g, the cured CLP-GDE films became highly resistant to abrasion and heat. When applied as a coating on wooden substrates, the particulate morphology enabled effective protection against water, stains, and sunlight with very thin layers (less than half the weight of commercial coatings) while retaining the wood's breathability excellently. Optimal hydrophobicity was reached with a coat weight of 6.9 g(CLP)/m2, resulting in water contact angle values of up to 120°. Due to their spherical shape and chemical structure, the CLPs acted as both a hardener and a particulate component in the coating, which removed the need for an underlying binding polymer matrix. Light interferometry measurements showed that while commercial polymeric film-forming coatings smoothened the substrate noticeably, the particulate morphology retained the substrate's roughness in lightweight coatings, allowing for a high water contact angle. This work presents new strategies for lignin applications in durable particulate coatings and their advantages compared to both currently used synthetic and bio-based coatings.


Assuntos
Coloides/química , Compostos de Epóxi/química , Éteres de Glicerila/química , Lignina/química , Nanopartículas/química , Coloides/efeitos da radiação , Compostos de Epóxi/efeitos da radiação , Éteres de Glicerila/efeitos da radiação , Interações Hidrofóbicas e Hidrofílicas , Luz , Lignina/efeitos da radiação , Teste de Materiais , Nanopartículas/efeitos da radiação , Pinus , Propriedades de Superfície , Temperatura , Água/química , Madeira/química
10.
Carbohydr Polym ; 254: 117480, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357931

RESUMO

With the increasing demand for greener alternatives to fossil-derived products, research on cellulose nanomaterials (CNMs) has rapidly expanded. The combination of nanoscale properties and sustainable attributes makes CNMs an asset in the quest for a sustainable society. However, challenges such as the hydrophilic nature of CNMs, their low compatibility with non-polar matrices and modest thermal stability, slow the development of end-uses. Combination of CNMs with amphiphilic lignin can improve the thermal stability, enhance the compatibility with non-polar matrices and, additionally, endow CNMs with new functionalities e.g., UV shielding or antioxidative properties. This article comprehensively reviews the different design strategies and their influence on properties and applications of CNMs containing lignin in various forms; either as residual lignin, added technical lignin, or nanoscale particles. The review focuses especially on the synergy created between CNMs and lignin, paving the way for new production routes and use of CNM/lignin materials in high-performance applications.


Assuntos
Celulose/química , Química Verde , Lignina/química , Nanoestruturas/química , Nanotecnologia/métodos , Anti-Infecciosos/química , Antioxidantes/química , Biomassa , Coloides , Humanos
11.
J Phys Chem B ; 125(44): 12315-12328, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34723534

RESUMO

Spherical lignin nanoparticles (LNPs) fabricated via nanoprecipitation of dissolved lignin are among the most attractive biomass-derived nanomaterials. Despite various studies exploring the methods to improve the uniformity of LNPs or seeking more application opportunities for LNPs, little attention has been given to the fundamental aspects of the solvent effects on the intrinsic properties of LNPs. In this study, we employed a variety of experimental techniques and molecular dynamics (MD) simulations to investigate the solvent effects on the intrinsic properties of LNPs. The LNPs were prepared from softwood Kraft lignin (SKL) using the binary solvents of aqueous acetone or aqueous tetrahydrofuran (THF) via nanoprecipitation. The internal morphology, porosity, and mechanical properties of the LNPs were analyzed with electron tomography (ET), small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), and intermodulation AFM (ImAFM). We found that aqueous acetone resulted in smaller LNPs with higher uniformity compared to aqueous THF, mainly ascribing to stronger solvent-lignin interactions as suggested by MD simulation results and confirmed with aqueous 1,4-dioxane (DXN) and aqueous dimethyl sulfoxide (DMSO). More importantly, we report that both LNPs were compact particles with relatively homogeneous density distribution and very low porosity in the internal structure. The stiffness of the particles was independent of the size, and the Young's modulus was in the range of 0.3-4 GPa. Overall, the fundamental understandings of LNPs gained in this study are essential for the design of LNPs with optimal performance in applications.


Assuntos
Lignina , Nanopartículas , Espalhamento a Baixo Ângulo , Solventes , Difração de Raios X
12.
Anal Chem ; 82(17): 7362-8, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20684532

RESUMO

The study of interactions between oppositely multicharged (macro)molecules remains a challenging issue. In frontal analysis capillary electrophoresis (FACE), it is difficult to avoid the adsorption of one of the interacting partners onto the capillary wall. In this work, we demonstrate the possibility to use FACE and affinity capillary electrophoresis (ACE) on a neutrally coated capillary for the study of interactions between a polycationic dendrigraft (or linear) poly-l-lysines, on one hand, and a multicharged anionic biomolecule (adenosine monophosphate, AMP, or adenosine triphosphate, ATP), on the other hand. A systematic comparison of four different neutral coatings (hydroxypropyl cellulose, polydimethylacrylamide, polyacrylamide, polyethylene glycol) has been performed based on the repeatability of the electrophoretic migration of the dendrigraft poly-l-lysines at pH close to neutrality. Both FACE and ACE methodogies were then used to study the interactions and to get the association constants and the stoichiometry of the complex. Multisite interactions, with two classes of independent sites, were determined. The specificity of the dendritic polylysine structure compared with linear polylysine in the interaction with ATP or AMP is also emphasized.


Assuntos
Ânions/química , Eletroforese Capilar/métodos , Poliaminas/química , Polilisina/química , Acrilamidas/química , Resinas Acrílicas/química , Monofosfato de Adenosina/química , Trifosfato de Adenosina/química , Adsorção , Celulose/análogos & derivados , Celulose/química , Concentração de Íons de Hidrogênio , Polieletrólitos , Polietilenoglicóis/química
13.
Acta Biomater ; 105: 223-238, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31926335

RESUMO

Targeting delivery of photosensitizers to mitochondria as the most sensitive cellular organelles to reactive oxygen species (ROS) by positively charged polymeric nanocarriers (NCs) is one of the useful methods for efficient photodynamic therapy (PDT). However, the NCs with positively charged mitochondria-targeting moieties are easily cleaned during circulation, restricting their in vivo applications. Herein, to address this issue and enhance in vivo PDT efficacy, we developed a sequential-targeting delivery system consisting of mitochondria-targeting micelles as the core prepared from the cationic amphiphilic copolymer for loading chlorin e6 (Ce6) and a tumor-targeting pH-dependent charge transformational layer as the shell obtained from 2,3-dimethylmaleic anhydride modified Biotin-PEG4000-NH2 (BioPEGDMA) via electrostatic interaction. Concealed by the anionic shell, the as-prepared NCs showed longer retention within the first stage of tumor-targeting. Then, the accumulated NCs conversed to positive charge in tumor extracellular microenvironment (pH ∼ 6.5), which could be more effectively internalized by tumor cells, and the re-exposed triphenylphosphonium (TPP) groups endowed their second-stage targetability to the mitochondria. In vivo experiments revealed that the Ce6-loaded NCs exhibited remarkable tumor inhibition rates of 84.1% and 93.2% on BALB/c nude mice and Kunming mice, respectively, under 660 nm NIR irradiation, and stimulated immune responses with upregulated expression of IFN-γ, TNF-α and CD3+ in tumor tissues, and enhanced activation of CD3+/CD4+, CD3+/CD8+ T lymphocytes and DCs in both tumor tissues and lymph glands. This work provided a new pathway for the development of smart drug delivery system with advanced PDT efficacy. STATEMENT OF SIGNIFICANCE: Although the existing targeting delivery of photosensitizers to mitochondria by positively charged nanocarriers (NCs) have efficiently enhanced photodynamic therapy (PDT), their positive charges caused rapid clearance during circulation, which has restricted their in vivo applications. Therefore, we fabricated a novel sequential-targeting NC to solve the problem. The tumor accumulated NCs conversed to positive charge in tumor extracellular microenvironment, and the re-exposed triphenylphosphonium groups initiated second-stage targetability to mitochondria. This system exhibited remarkable tumor inhibition efficiency both in vitro and in vivo. Moreover, as we hypothesized, mitochondria-located PDT could promote immune response, resulting in improvement of PDT. The strategy of sequential targeting-based PDT in combination with augmented immune response showed a novel pathway for the development of smart drug delivery system with advanced PDT.


Assuntos
Portadores de Fármacos/química , Imunoterapia , Mitocôndrias/metabolismo , Nanopartículas/química , Neoplasias/terapia , Fotoquimioterapia , Animais , Antineoplásicos/farmacologia , Apoptose , Linhagem Celular Tumoral , Sobrevivência Celular , Clorofilídeos , Citocromos c/metabolismo , Fluorescência , Concentração de Íons de Hidrogênio , Metacrilatos/síntese química , Metacrilatos/química , Camundongos Endogâmicos BALB C , Camundongos Nus , Micelas , Neoplasias/imunologia , Neoplasias/patologia , Tamanho da Partícula , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Porfirinas/química , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Distribuição Tecidual
14.
Mater Sci Eng C Mater Biol Appl ; 98: 737-745, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30813078

RESUMO

Controlled release of incorporated foreign DNA from multilayered films plays an important role in surface-mediated gene delivery. Herein, multilayered polyelectrolyte complex thin films, composed of dendrimer-grafted bio-reducible cationic poly(disulfide amine) and plasmid DNA, were fabricated via layer-by-layer (LBL) assembly for in vitro localized gene delivery. The UV absorbance and thickness of the LBL films were found to have linear correlation with the numbers of poly(disulfide amine)/DNA bilayers. Although LBL films were stable in PBS buffer, their degradation could be triggered by reducing agents (i.e. glutathione, GSH). The degradation rate of the films is directly proportional to the GSH concentration, which in turn affected the corresponding gene expression. All poly(disulfide amine)/DNA films exhibited lower cytotoxicity and higher transfection activity in comparison with PEI/DNA multilayered films. Moreover, LBL films showed the highest transfection efficiency in the presence of 2.5 mM GSH when cultured with 293T cells, with ~36% GFP-positive 293T cells after 5-days of co-culture. These DNA-containing reducible films could potentially be useful in gene therapy and tissue engineering by controlling the release of incorporated DNA.


Assuntos
DNA/química , Dendrímeros/química , Poliaminas/química , Polímeros/química , Materiais Biocompatíveis/química , Adesão Celular/efeitos dos fármacos , Células HEK293 , Humanos , Poliaminas/efeitos adversos , Polieletrólitos , Polímeros/efeitos adversos
15.
Colloids Surf B Biointerfaces ; 178: 263-268, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30877911

RESUMO

Ammonium bicarbonate (ABC) liposomes can only release drugs extracellularly while intracellular drug delivery could be more promising than extracellular release in chemotherapy. The purpose of this work was to endow the ABC liposomes with tumor-triggered targeting effect, to realize the intracellular drug release and retain the long circulation characteristics of the liposomes. The tumor-triggered targeting ABC (TT-ABC) liposomes were proposed to improve uptake of tumor cells owing to folate (FA) - specific binding. To retain the long circulation characteristics of the TT-ABC liposomes, we synthesized PEGylated phospholipid with a pH-sensitive imine bond (DSPE-PEG5000) and added it to the liposomes. After endocytosis by tumor cells via active targeting, the TT-ABC liposomes produced carbon dioxide (CO2) bubbles at elevated temperature or in the acidic endo/lysosome. The permeable defects could be created in the phospholipid bilayer by the generating CO2 bubbles, so the liposomes could quickly release the drugs intracellularly. Doxorubicin (DOX) loaded TT-ABC (DOX@TT-ABC) liposomes exhibited good stability at physiological pH (7.4) and released DOX quickly at reduced pH (6.4) and hyperthermia (42 °C). DOX@TT-ABC liposomes showed significantly enhanced cellular uptake, intracellular accumulation of DOX, and cytotoxicity at pH 6.4 and 42 °C.


Assuntos
Bicarbonatos/química , Doxorrubicina/química , Lipossomos/química , Animais , Sistemas de Liberação de Medicamentos/métodos , Humanos , Concentração de Íons de Hidrogênio , Bicamadas Lipídicas/química
16.
J Biomed Mater Res A ; 83(3): 696-702, 2007 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17530633

RESUMO

Cholic acid functionalized star oligo/poly(DL-lactide)s with different molecular weights were synthesized through the ring-opening polymerization of DL-lactide initiated by cholic acid. On the basis of the specific physicochemical properties of the star oligo/poly(DL-lactide)s, submicron sized drug-delivery systems were fabricated using a very convenient "ultrasonic dispersion method," which did not involve toxic organic solvents. The drug-loaded microspheres had a regular spherical shape with a narrow size distribution. The effects of ultrasonic power and the molecular weight of polymers on the microsphere fabrication were investigated. The in vitro drug release was studied. The release profiles were fitted by the classical empirical exponential expression. The fitting result indicated that the drug release was controlled by combined degradation and diffusion mechanism.


Assuntos
Ácido Cólico/química , Microesferas , Poliésteres/química , Preparações de Ação Retardada/química , Microscopia Eletrônica de Varredura , Propriedades de Superfície
17.
J Biomed Mater Res B Appl Biomater ; 82(2): 400-7, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17245744

RESUMO

Novel cholic acid functionalized star oligo/poly(DL-lactide)s with different molecular weights were synthesized through the ring-opening polymerization of DL-lactide initiated by cholic acid. Compared with poly(DL-lactide), these star oligo/poly(DL-lactide)s show faster hydrolytic degradation rates, and the degradation mechanism changes from bulk erosion to surface erosion with decreasing molecular weight. Based on the specific physicochemical properties of the novel star oligo/poly(DL-lactide), the drug delivery system with submicron size was fabricated using a very convenient "ultrasonic dispersion method" which did not involve toxic organic solvents. The in vitro drug release was studied.


Assuntos
Ácido Cólico/química , Sistemas de Liberação de Medicamentos , Poliésteres/química , Tamanho da Partícula , Poliésteres/síntese química , Prednisona/administração & dosagem , Ultrassom
18.
J Biotechnol ; 214: 147-55, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26433047

RESUMO

We prepared and characterized polymersomes functionalized with nanobodies (VHHs) on the basis of biocompatible, biodegradable and FDA-approved poly(ethylene glycol)-block-poly(ϵ-caprolactone) (PEG-b-PCL). Fluorescein isothiocyanate (FITC) and N-beta-maleimidopropyl-oxysuccinimide ester were allowed reacting with H2N-PEG-b-PCL to produce FITC and maleimide (Mal) functionalized copolymers, Mal-PEG-b-PCL and FITC-PEG-b-PCL. A mixture of MeO-PEG-b-PCL, Mal-PEG-b-PCL and FITC-PEG-b-PCL was used to prepare polymersomes by thin film hydration and nanoprecipitation methods. Morphological studies by cryogenic transmission electron microscopy (Cryo-TEM) showed that the nanoparticles exhibited predominantly vesicular structures (polymersomes). Their mean diameters measured by dynamic light scattering were around 150 nm and the zeta-potentials around -1 mV at pH 7.4. The nanoparticles were functionalized with either anti-HER2 (VHH1) or anti-GFP (VHH2) nanobodies using maleimide-cysteine chemistry. Their particle size and zeta-potential increased slightly after nanobody-functionalization. The specific binding of VHH-functionalized polymersomes and control nanoparticles towards HER2 positive breast cancer cells was analyzed by flow cytometry and confocal microscopy. The collected results represent the first report which experimentally demonstrates that VHH1-functionalized PEO-b-PCL polymersomes can target specifically breast cancer cells expressing HER2 receptors. The detailed morphological and cell-binding studies described herein pave the way for future in vivo studies to evaluate the feasibility to use such nanoparticles for targeted drug delivery.


Assuntos
Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Lactonas/química , Polietilenoglicóis/química , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/metabolismo , Linhagem Celular Tumoral , Microscopia Crioeletrônica , Humanos , Tamanho da Partícula , Receptor ErbB-2/metabolismo
19.
Food Funct ; 5(6): 1278-85, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24741679

RESUMO

The bovine serum albumin (BSA)-epigallocatechin gallate (EGCG) nanoparticles were fabricated using a desolvation method, and coated with poly-ε-lysine or chitosan. BSA-EGCG nanoparticles (BEN), poly-ε-lysine coated BSA-EGCG nanoparticles (PBEN), and chitosan coated BSA-EGCG nanoparticles (CBEN) had a spherical morphology and a size of 186, 259, and 300 nm, respectively. The loading efficiency of EGCG in these nanoparticles was 32.3%, 35.4%, and 32.7%, whereas the loading capacity was 18.9%, 17.0%, and 16.0% (w/w), respectively. Poly-ε-lysine or chitosan coating prevented the aggregation of nanoparticles at pH 4.5-5.0. However, they caused particle aggregation at pH 6.5-7.0. BEN had negative zeta-potentials between pH 4.5 and 6.0. Poly-ε-lysine or chitosan coating changed the zeta-potentials to positive. The release study of EGCG from the nanoparticles in the simulated gastric or intestinal fluid with or without digestive enzymes showed that poly-ε-lysine and chitosan coatings delayed EGCG release from the nanoparticles. Poly-ε-lysine or chitosan coating improved the stability of EGCG during storage at 60 °C compared with EGCG in the uncoated particles. EGCG in BEN, PBEN, and CBEN had a decreasing apparent permeability coefficient (Papp) on Caco-2 monolayers, whereas pure EGCG showed relatively stable Papp during the incubation over time. EGCG in CBEN showed significantly higher Papp, suggesting that chitosan coated BSA-EGCG nanoparticles may improve the absorption of EGCG.


Assuntos
Catequina/análogos & derivados , Intestinos/efeitos dos fármacos , Nanopartículas/química , Soroalbumina Bovina/química , Disponibilidade Biológica , Transporte Biológico , Células CACO-2 , Catequina/química , Catequina/farmacocinética , Quitosana/química , Materiais Revestidos Biocompatíveis/química , Humanos , Concentração de Íons de Hidrogênio , Mucosa Intestinal/metabolismo , Tamanho da Partícula , Peptídeo Hidrolases/metabolismo , Polilisina/química
20.
Eur J Pharm Biopharm ; 82(1): 36-42, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22641023

RESUMO

Cocoa procyanidins (CPs)-gelatin-chitosan nanoparticles were fabricated based on the procyanidin-protein and electrostatic interactions, with an objective to enhance the stability and bioactivity of CPs. The CPs were purified using chromatographic methods and analyzed using HPLC equipped with a fluorescence detector (FLD) and mass spectrometer (MS). The purified CPs had a purity of 53.1% (w/w) and contained procyanidin oligomers (from monomer to decamers) and polymers, with polymers being the predominant component (26.4%, w/w). Different CPs-gelatin-chitosan mass ratios were tested to investigate the effects of formulation on the nanoparticle fabrication. Using CPs-gelatin-chitosan mass ratio of 0.75:1:0.5, the resultant nanoparticles had a particle size of 344.7 nm, zeta-potential of +29.8 mV, particle yield of 51.4%, loading efficiency of 50.1%, and loading capacity of 20.5%. The CPs-gelatin-chitosan nanoparticles were spherical as observed by scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FTIR) suggested that the primary interaction between the CPs and gelatin was hydrogen bond and hydrophobic interaction, while electrostatic interaction was the main binding force between chitosan and CPs-gelatin nanoparticles. Nanoencapsulation of the CPs significantly improved the stability of the CPs at 60°C. The CPs-gelatin-chitosan nanoparticles showed the same apoptotic effects at lower concentrations in human acute monocytic leukemia THP-1 cells compared with the CPs in solution.


Assuntos
Quitosana/química , Gelatina/química , Nanopartículas , Proantocianidinas/farmacologia , Apoptose/efeitos dos fármacos , Cacau/química , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Portadores de Fármacos/química , Estabilidade de Medicamentos , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Leucemia Monocítica Aguda/metabolismo , Espectrometria de Massas , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Polímeros/química , Proantocianidinas/administração & dosagem , Proantocianidinas/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Temperatura
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