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1.
Chem Pharm Bull (Tokyo) ; 67(4): 389-392, 2019 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-30662018

RESUMEN

In this study, we aimed to investigate the effects of stabilizers and processing parameters on the size reduction of alpha-mangostin (AMG) using high-pressure homogenization (HPH). The solubility of AMG in various stabilizers was studied. Selected stabilizers were used to prepare AMG suspensions by HPH under different conditions. After HPH, the particle size of AMG suspensions with stabilizers significantly decreased to microns. Percent size reduction efficiency of all AMG suspensions with each stabilizer increased with the increase in the number of homogenization cycles. Sodium lauryl sulfate and poloxamer188 provided a greater extent of particle size reduction than polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer. AMG suspensions with binary stabilizers at higher pressure were also prepared. The use of high pressure increased percent size reduction efficiency.


Asunto(s)
Presión , Xantonas/química , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Poloxámero/química , Polietilenglicoles/química , Polivinilos/química , Dodecil Sulfato de Sodio/química , Solubilidad , Suspensiones/química
2.
Mol Ther Nucleic Acids ; 12: 33-44, 2018 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-30195771

RESUMEN

The use of the gastrointestinal tract as a site for the local delivery of DNA is an exciting prospect. In order to obtain an effective vector capable of delivering a gene of interest to target cells to achieve sufficient and sustained transgene expression, with minimal toxicity, we developed a new generation of filamentous bacteriophage. This particular bacteriophage was genetically engineered to display an arginine-glycine-aspartic acid (RGD) motif (an integrin-binding peptide) on the major coat protein pVIII and carry a mammalian DNA cassette. One unanticipated observation is the thermoresponsive behavior of engineered bacteriophage. This finding has led us to simplify the isolation method to purify bacteriophage particles from cell culture supernatant by low-temperature precipitation. Our results showed that, in contrast to non-surface modified, the RGD-modified bacteriophage was successfully used to deliver a transgene to mammalian cells. Our in vitro model of the human intestinal follicle-associated epithelium also demonstrated that bacteriophage particles were stable in simulated gastrointestinal fluids and able to cross the human intestinal barrier. In addition, we confirmed an adjuvant property of the engineered bacteriophage to induce nitric oxide production by macrophages. In conclusion, our study demonstrated the possibility of using bacteriophage for gene transfer in the gastrointestinal tract.

3.
Int J Pharm ; 538(1-2): 21-29, 2018 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-29225100

RESUMEN

In this study, the inclusion complex formation between α-mangostin and water-soluble quaternized ß-CD grafted-chitosan (QCD-g-CS) was investigated. Inclusion complex formation with encapsulation efficiency (%EE) of 5, 15 and 75% can be varied using high speed homogenizer. Tuning %EE plays a role on physicochemical and biological properties of α-mangostin/QCD-g-CS complex. Molecular dynamics simulations indicate that α-mangostin is included within the hydrophobic ß-CD cavity and being absorbed on the QCD-g-CS surface, with these results being confirmed by Fourier transform infrared (FTIR) spectroscopy. Probing the release characteristics of the inclusion complex at various %EE (5%, 15% and 75%) in simulated saliva (pH 6.8) demonstrated that α-mangostin release rates were dependent on % EE (order 5% > 15% > 75%). Additionally, higher antimicrobial and anti-inflammation activities were observed for the inclusion complex than those of free α-mangostin due to enhance the solubility of α-mangostin through the inclusion complex with QCD-g-CS.


Asunto(s)
Química Farmacéutica/métodos , Quitosano/química , Xantonas/administración & dosificación , beta-Ciclodextrinas/química , Antiinfecciosos/administración & dosificación , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antiinflamatorios/administración & dosificación , Antiinflamatorios/química , Antiinflamatorios/farmacología , Línea Celular , Portadores de Fármacos/química , Liberación de Fármacos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Simulación de Dinámica Molecular , Saliva/metabolismo , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Agua/química , Xantonas/química , Xantonas/farmacología
4.
Drug Dev Ind Pharm ; 43(7): 1082-1092, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28161991

RESUMEN

This study was aimed to examine the nanoparticle formation from redispersion of binary and ternary solid dispersions. Binary systems are composed of various ratios of glibenclamide (GBM) and polyvinylpyrrolidone K30 (PVP-K30), whereas a constant amount at 2.5%w/w of a surfactant, sodium lauryl sulfate (SLS) or Gelucire44/14 (GLC), was added to create ternary systems. GBM nanoparticles were collected after the systems were dispersed in water for 15 min. The obtained nanoparticles were characterized for size distribution, crystallinity, thermal behavior, molecular structure, and dissolution properties. The results indicated that GBM nanoparticles could be formed when the drug content of the systems was lower than 30%w/w in binary systems and ternary systems containing SLS. The particle size ranged from 200 to 500 nm in diameter with narrow size distribution. The particle size was increased with increasing drug content in the systems. The obtained nanoparticles were spherical and showed the amorphous state. Furthermore, because of being amorphous form and reduced particle size, the dissolution of the generated nanoparticles was markedly improved compared with the GBM powder. In contrast, all the ternary solid dispersions prepared with GLC anomalously provided the crystalline particles with the size ranging over 5 µm and irregular shape. Interestingly, this was irrelevant to the drug content in the systems. These results indicated the ability of GLC to destabilize the polymer network surrounding the particles during particle precipitation. Therefore, this study suggested that drug content, quantity, and type of surfactant incorporated in solid dispersions drastically affected the physicochemical properties of the precipitated particles.


Asunto(s)
Gliburida/química , Nanopartículas/química , Povidona/química , Tensoactivos/química , Rastreo Diferencial de Calorimetría , Química Farmacéutica , Portadores de Fármacos/química , Estabilidad de Medicamentos , Dodecil Sulfato de Sodio , Solubilidad
6.
Int J Biol Macromol ; 84: 472-80, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26552020

RESUMEN

Two guest molecules (eugenol and (-)-menthol) were investigated on inclusion complex formation with water-soluble quaternized ß-CD grafted with chitosan (QCD-g-CS). The inclusion complexes were prepared at varying mole ratios between eugenol or (-)-menthol and ß-CD (substituted on QCD-g-CS) by a conventional shaking method and obtained as solid powder by freeze-drying process. The results showed that encapsulation efficiency %EE decreased with increasing of initial eugenol or (-)-menthol loading whereas %loading increased with increasing of initial eugenol or (-)-menthol loading. The results indicated that inclusion complex formation between eugenol and QCD-g-CS was more favorable than that of (-)-menthol. To clarify this mechanism, molecular dynamics simulations were performed to explore their binding energy, solvation energy and total free energy of those complexes. It was found that the total free energy (ΔG) of eugenol and (-)-menthol against QCD-g-CS (mole ratio of 1) in water-explicit system were -2108.91 kJ/mol and -344.45 kJ/mol, respectively. Moreover, molecular dynamic simulation of eugenol absorbed on surface QCD-g-CS (-205.73 kJ/mol) was shown to have a higher negative value than that of (-)-menthol on QCD-gCS (3182.31 kJ/mol). Furthermore, the release characteristics of the encapsulated powder were also investigated in simulated saliva pH 6.8 at 32 °C. The results suggested that (-)-menthol had higher release rate from the complexes than eugenol. In all cases, the release characteristics for those guest molecules could be characterized by the limited-diffusion kinetics.


Asunto(s)
Quitosano/química , Eugenol/química , Mentol/química , beta-Ciclodextrinas/química , Rastreo Diferencial de Calorimetría , Eugenol/administración & dosificación , Mentol/administración & dosificación , Modelos Moleculares , Conformación Molecular , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica , Agua/química
7.
Drug Dev Ind Pharm ; 42(1): 70-79, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25835067

RESUMEN

Modification of polymorphic forms of poorly water-soluble drugs is one way to achieve the desirable properties. In this study, glibenclamide (GBM) particles with different polymorphic forms, including a new metastable form, were obtained from redispersion of ternary solid dispersion systems. The ternary solid dispersion systems, consisting of GBM, polyvinylpyrrolidone-K30 (PVP-K30) and sodium lauryl sulfate (SLS), were prepared by solvent evaporation method and subsequently redispersed in deionized water. The precipitated drug particles were then collected at a given time period. The drug particles with different polymorphic forms could be achieved depending on the polymer/surfactant ratio. Amorphous drug nanoparticles could be obtained by using a high polymer/surfactant ratio, whereas two different crystalline forms were obtained from the systems containing low polymer/surfactant ratios. Interestingly, a new metastable form IV of GBM with improved dissolution behavior could be obtained from the system of GBM:PVP-K30:SLS with the weight ratio of 2:2:4. This new polymorphic form IV of GBM was confirmed by differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffractometry (PXRD) and solid state 13C nuclear magnetic resonance (NMR) spectroscopy. The molecular arrangement of the new polymorphic form IV of GBM was proposed. The GBM particles with polymorphic form IV also showed an improved dissolution behavior. In addition, it was found that the formation of the new polymorphic form IV of GBM by this process was reproducible.


Asunto(s)
Portadores de Fármacos/química , Composición de Medicamentos , Gliburida/química , Povidona/química , Dodecil Sulfato de Sodio/química , Rastreo Diferencial de Calorimetría , Cristalización , Gliburida/administración & dosificación , Espectroscopía de Resonancia Magnética , Nanopartículas/química , Solubilidad , Solventes/química , Espectroscopía Infrarroja por Transformada de Fourier , Tensoactivos/química , Difracción de Rayos X
8.
Int J Pharm ; 498(1-2): 347-54, 2016 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-26707411

RESUMEN

Purpose of this study was to investigate the ability of octenyl succinic anhydride (OSA) starch as emulsifier and solid carrier in dry emulsion (DE) and dry suspension (DS) formulations. Fenofibrate (FF) was loaded at lower and higher than its saturation concentration in oil phase to prepare the DE and DS by spray drying method. The DE and DS were successfully prepared with 36-48% and 46% production yield, respectively. After reconstitution in water, the emulsion with mean droplet size of 1-2 µm was obtained. Solid state characterization revealed the amorphous state of FF and the crystalline state of OSA starch in both DE and DS formulations. Both DE and DS enhanced FF dissolution rate compared to pure material and DS showed the highest dissolution rate. The DE and DS could be compressed to the tablets with acceptable disintegration time and without changeable dissolution profile. Moreover, the dissolution profiles of both DE and DS remained unchanged after 2 months storage at 40 °C.


Asunto(s)
Portadores de Fármacos/síntesis química , Emulsionantes/síntesis química , Fenofibrato/síntesis química , Almidón/síntesis química , Anhídridos Succínicos/síntesis química , Química Farmacéutica , Portadores de Fármacos/análisis , Emulsionantes/análisis , Fenofibrato/análisis , Solubilidad , Almidón/análisis , Anhídridos Succínicos/análisis , Suspensiones , Difracción de Rayos X/métodos
9.
J Liposome Res ; 26(1): 69-79, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25945393

RESUMEN

CONTEXT: Oral delivery of peptide and protein drugs still remains the area of challenges due to their low stability and permeability across GI tract. Among numerous attempts, the receptor-mediated drug targeting is a promising approach to enhance GI permeability. OBJECTIVE: The aim of this study was to prepare mannosylated buserelin acetate (MANS-BA) proliposome powders grafted with N-octadecyl-d-mannopyranosylamine (SAMAN) as targeting moiety and evaluate their permeability across Caco-2 cell monolayers. MATERIALS AND METHODS: The MANS-BA proliposome powders were prepared by coprecipitation method. The targeting moiety SAMAN was synthesized in-house and confirmed by characterization using Fourier transform infrared (FTIR) and differential scanning calorimeter (DSC). RESULTS: The MANS-BA liposomes reconstituted from proliposome powders exhibited the oligolamellar vesicular structure of phospholipid bilayer. Their size, zeta potential and entrapment efficiency were in the ranges of 93.11-218.95 nm, -24.03 to -37.15 mV and 21.12-33.80%, respectively. The permeability of reconstituted MANS-BA liposomes across Caco-2 cell monolayers was significantly enhanced to about 1.2- and 2.2-fold over those of conventional BA liposomes and solution, respectively. DISCUSSION: Increase in dicetylphosphate, cholesterol and SAMAN contents resulted in significant increase in size and zeta potential of reconstituted MAN-BA liposomes. The entrapment efficiency was increased with increasing dicetylphosphate and mannitol contents in liposomes containing cholesterol. CONCLUSIONS: The significantly enhanced permeability across Caco-2 cell monolayers of MANS-BA liposomes might be due to the role of mannose receptor on intestinal enterocytes.


Asunto(s)
Amino Azúcares/química , Buserelina/química , Liposomas/química , Amino Azúcares/síntesis química , Buserelina/síntesis química , Células CACO-2 , Humanos , Ligandos , Liposomas/síntesis química , Permeabilidad
10.
Int J Biol Macromol ; 80: 651-8, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26193680

RESUMEN

The objectives of this study were to investigate the adsorption behavior of lysozyme (LSZ) onto magnesium aluminum silicate (MAS) at various pHs and to characterize the LSZ-MAS microparticles obtained from the molecular interaction between LSZ and MAS. The results showed that LSZ could be bound onto the MAS layers at different pHs, leading to the formation of LSZ-MAS microparticles. The higher preparation pH permitted greater adsorption affinity but a lower adsorption capacity of LSZ onto MAS. LSZ could interact with MAS via hydrogen bonds and electrostatic forces, resulting in the formation of intercalated nanocomposites. The particle size, %LSZ adsorbed, and LSZ release rate of LSZ-MAS microparticles increased when the LSZ-MAS ratio was increased. The secondary structure of LSZ bound onto the MAS layers in microparticles prepared at various pHs was altered compared with that of native LSZ. Moreover, the LSZ extracted from microparticles prepared at pH 4 showed an obvious change in the tertiary structure, leading to a decrease in the biological activity of the LSZ released. These findings suggested that LSZ can strongly interact with MAS to form microparticles that may potentially be used as delivery systems for sustained protein release.


Asunto(s)
Compuestos de Aluminio/química , Compuestos de Magnesio/química , Muramidasa/química , Nanocompuestos/química , Silicatos/química , Adsorción , Enlace de Hidrógeno , Concentración de Iones de Hidrógeno , Modelos Moleculares , Nanocompuestos/ultraestructura , Tamaño de la Partícula , Conformación Proteica , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática
11.
Int J Pharm ; 492(1-2): 92-102, 2015 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-26143232

RESUMEN

Nanocarriers based on electrostatic Layer-by-layer (LbL) assembly of CaCO3 nanoparticles (CaCO3 NPs) was investigated. These inorganic nanoparticles was used as templates to construct nanocapsules made from films based on two oppositely charged polyelectrolytes, poly(diallyldimethylammonium chloride), and poly (sodium 4-styrene-sulfonate sodium salt), followed by core dissolution. The naked CaCO3 NPs, CaCO3 NPs coated with the polyelectrolytes and hollow nanocapsules were found with hexagonal shape with average sizes of 350-400 nm. A reversal of the surface charge between positive to negative zeta potential values was found, confirming the adsorption of polyelectrolytes. The loading efficiency and release of curcumin were controlled by the hydrophobic interactions between the drug and the polyelectrolyte matrix of the hollow nanocapsules. The quantity of curcumin released from hollow nanocapsules was found to increase under acidic environments, which is a desirable for anti-cancer drug delivery. The hollow nanocapsules were found to localize in the cytoplasm and nucleus compartment of Hela cancer cells after 24 h of incubation. Hollow nanocapsules were non-toxic to human fibroblast cells. Furthermore, curcumin loaded hollow nanocapsules exhibited higher in vitro cell inhibition against Hela cells than that of free curcumin, suggesting that polyelectrolyte based-hollow nanocapsules can be utilized as new carriers for drug delivery.


Asunto(s)
Curcumina , Portadores de Fármacos , Nanocápsulas , Carbonato de Calcio/química , Línea Celular , Supervivencia Celular/efectos de los fármacos , Curcumina/administración & dosificación , Curcumina/química , Curcumina/farmacología , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/química , Portadores de Fármacos/farmacología , Liberación de Fármacos , Endocitosis , Células HeLa , Humanos , Nanocápsulas/administración & dosificación , Nanocápsulas/química , Polietilenos/química , Poliestirenos/química , Compuestos de Amonio Cuaternario/química
12.
Colloids Surf B Biointerfaces ; 130: 229-36, 2015 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-25937384

RESUMEN

Mucoadhesive poly (lactic-co-glycolic acid) (PLGA) nanoparticles having a modified shell-matrix derived from polyvinyl alcohol (PVA) and Carbopol (CP), a biodegradable polymer coating, to improve the adhesion and cell transfection properties were developed. The optimum formulations utilized a CP concentration in the range of 0.05-0.2%w/v, and were formed using modified emulsion-solvent evaporation technique. The resulting CP-PLGA nanoparticles were characterized in terms of their physical and chemical properties. The absorbed CP on the PLGA shell-matrix was found to affect the particle size and surface charge, with 0.05% CP giving rise to smooth spherical particles (0.05CP-PLGA) with the smallest size (285.90 nm), and strong negative surface charge (-25.70 mV). The introduction of CP results in an enhancement of the mucoadhesion between CP-PLGA nanoparticles and mucin particles. In vitro cell internalization studies highlighted the potential of 0.05CP-PLGA nanoparticles for transfection into SiHa cells, with uptake being time dependent. Additionally, cytotoxicity studies of CP-PLGA nanoparticles against SiHa cancer cells indicated that low concentrations of the nanoparticles were non-toxic to cells (cell viability >80%). From the various formulations studied, 0.05CP-PLGA nanoparticles proved to be the optimum model carrier having the required mucoadhesive profile and could be an alternative therapeutic efficacy carrier for targeted mucosal drug delivery systems with biodegradable polymer.


Asunto(s)
Resinas Acrílicas/química , Adhesivos/química , Ácido Láctico/química , Nanopartículas/química , Ácido Poliglicólico/química , Adhesión Celular , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Endocitosis , Humanos , Ácido Láctico/farmacología , Espectroscopía de Resonancia Magnética , Microscopía Confocal , Microscopía Electrónica de Transmisión , Mucinas/química , Nanopartículas/administración & dosificación , Nanopartículas/ultraestructura , Tamaño de la Partícula , Ácido Poliglicólico/farmacología , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Alcohol Polivinílico/química , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie
13.
Int J Pharm ; 477(1-2): 261-72, 2014 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-25455774

RESUMEN

Curcumin (CM) has demonstrated safety and efficacy as a drug, but its pharmaceutical role is restricted as a result of extremely low aqueous solubility, rapid systemic elimination, inadequate tissue absorption and degradation at alkaline pH; properties that severely curtail its bioavailability. To address this issue, CM was encapsulated within pH responsive amphiphilic chitosan, resulting in the formation of 100 nm spontaneously self-assembled polymeric micelles in water. The amphiphilic chitosan, namely N-benzyl-N,O-succinyl chitosan (BSCS), was prepared by reductive N-benzylation and N,O-succinylation. The stability of micelles after being re-dispersed in water was investigated using glycine as a cryoprotectant, and the average sizes were shown to be maintained at a level lower than 200 nm for up to 4 months, at temperatures of 4°C and 25°C. In vitro drug release results showed that CM was slowly released from the micelles without any burst effect in the intestine (pH 5.5-7.4), with limited release in the stomach (pH 1.2). Cytotoxicity assays indicated that CM loaded micelles showed half maximal inhibitory concentrations (IC50) 4.7-, 3.6-, and 12.2-fold lower than that of free CM in HeLa, SiHa and C33a cervical cell lines, respectively. Cellular uptake of micelles was confirmed by confocal laser scanning microscopy and flow cytometry, with a 6-fold significant increase in the amount of CM loaded micelles compared to free CM in all cervical cancer cells. Notably, CM loaded micelles promoted an increase (30-55%) in the percentage of early apoptosis of HeLa, SiHa and C33a cells, compared to free CM. These results suggest that BSCS micelles may be a promising carrier for effective oral delivery of CM.


Asunto(s)
Antineoplásicos/administración & dosificación , Apoptosis/efectos de los fármacos , Quitosano/análogos & derivados , Curcumina/administración & dosificación , Portadores de Fármacos/síntesis química , Tensoactivos/síntesis química , Neoplasias del Cuello Uterino/patología , Antineoplásicos/farmacología , Técnicas de Cultivo de Célula , Quitosano/síntesis química , Quitosano/química , Curcumina/farmacología , Portadores de Fármacos/química , Liberación de Fármacos , Estabilidad de Medicamentos , Femenino , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Micelas , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Propiedades de Superficie , Tensoactivos/química , Neoplasias del Cuello Uterino/tratamiento farmacológico
14.
AAPS PharmSciTech ; 15(6): 1357-69, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24927669

RESUMEN

Tackiness caused by the gas-entrapped membrane (Eudragit(®)RL 30D) was usually observed during storage of the effervescent floating tablets, leading to failure in floatation and sustained release. In this work, common anti-tacking agents (glyceryl monostearate (GMS) and talc) were used to solve this tackiness problem. The impact of anti-tacking agent on the properties of free films and corresponding floating tablets was investigated. GMS was more effective than talc in reducing tackiness of the film. Addition and increasing amount of anti-tacking agents lowered the film mechanical strength, but the coating films were still strong and flexible enough to resist the generated gas pressure inside the floating tablet. Wettability and water vapor permeability of the film decreased with increasing level of anti-tacking agents as a result of their hydrophobicity. No interaction between anti-tacking agents and polymer was observed as confirmed by Fourier transform infrared spectroscopy, powder X-ray diffractometry, and differential scanning calorimetry studies. Increasing amount of anti-tacking agents decreased time to float and tended to retard drug release of the floating tablets. Floating properties and drug release were also influenced by type of anti-tacking agents. The obtained floating tablets still possessed good floating properties and controlled drug release even though anti-tacking agent had some effects. The results demonstrated that the tackiness problem of the floating tablets could be solved by incorporating anti-tacking agent into the gas-entrapped membrane.


Asunto(s)
Resinas Acrílicas/química , Excipientes/química , Glicéridos/química , Membranas Artificiales , Talco/química , Adhesividad , Rastreo Diferencial de Calorimetría , Química Farmacéutica , Preparaciones de Acción Retardada , Gases , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Modelos Químicos , Permeabilidad , Presión , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Comprimidos , Tecnología Farmacéutica/métodos , Agua/química , Difracción de Rayos X
15.
Biomacromolecules ; 15(8): 2879-88, 2014 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-24956200

RESUMEN

Highly fluorescent N-substituted 1-cyanobenz[f]isoindole chitosans (CBI-CSs) with various degrees of N-substitution (DS) were synthesized by reacting chitosan (CS) with naphthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide under mild acidic conditions. Introduction of 1-cyanobenz[f]isoindole moieties into the CS backbone resulted in lowering of polymer thermal stability and crystallinity. The fluorescence quantum yield (Φf) of CBI-CS was found to be DS- and molecular-weight-dependent, with Φf decreasing as DS and molecular weight were increased. At similar DS values, CBI-CS exhibited 26 times higher Φf in comparison with fluorescein isothiocyanate-substituted chitosan (FITC-CS). CBI-CS/TPP nanoparticles were fabricated using an ionotropic gelation method in which pentasodium triphosphate (TPP) acted as a cross-linking agent. CS and CBI-CS exhibited low cytotoxicity to normal skin fibroblast cells over a concentration range of 0.1-1000 µg/mL, while an increased cytotoxicity level was evident in CBI-CS/TPP nanoparticles at concentrations greater than 100 µg/mL. In contrast with CBI-CS polymers, the CBI-CS/TPP nanoparticles exhibited lower fluorescence; however, confocal microscopy results showed that living normal skin fibroblast cells became fluorescent on nanoparticle uptake. These results suggest that CBI-CS and fabricated nanoparticles thereof may be promising fluorescence probes for live cell imaging.


Asunto(s)
Quitosano , Fibroblastos/citología , Colorantes Fluorescentes , Nanopartículas/química , Quitosano/química , Quitosano/farmacología , Colorantes Fluorescentes/síntesis química , Colorantes Fluorescentes/química , Colorantes Fluorescentes/farmacología , Humanos , Microscopía Fluorescente/métodos
16.
J Microencapsul ; 31(6): 609-18, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24861323

RESUMEN

Fine-tuning the nanoscale structure and morphology of nanostructured lipid carriers (NLCs) is central to improving drug loading and stability of the particles. The role of surfactant charge on controlling the structure, the physicochemical properties and the stability of NLCs has been investigated using three surfactant types (cationic, anionic, non-ionic), and mixed surfactants. Either one, a mixture of two, or a mixture of three surfactants were used to coat the NLCs, with these classified as one, two and three surfactant systems, respectively. The mixed (two and three) surfactant systems produced smaller NLC particles and yielded NLCs with lower crystallinity than the one surfactant system. The combined effects of the ionic and the non-ionic surfactants may play a key role in assisting the lipid-oil mixing, as well as maintaining colloidal repulsion between NLC particles. In contrast, for the three surfactant system, the lipid-oil mixture in the NLCs appeared less homogenous. This was also reflected in the results of the stability study, which indicated that NLC particle sizes in two surfactant systems appeared to be retained over longer periods than for other surfactant systems.


Asunto(s)
Portadores de Fármacos/química , Lípidos/química , Nanoestructuras/química , Tensoactivos/química , Coloides , Aceites/química
17.
Carbohydr Polym ; 104: 17-22, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24607154

RESUMEN

Methylated N-pyridylmethyl chitosan chlorides (M-PyMeChCs) with a similar total degree of quaternization (DQT) and molecular weight but different N-pyridinium positions were synthesized by reductive amination and methylation, respectively. The effect of N-pyridinium positions on transfection efficiency and cytotoxicity was investigated in human hepatoma (Huh7) cell lines. The results revealed that M-PyMeChCs are able to form a complete complex formation with DNA since there is an N/P ratio of 5. The particle sizes of M-PyMeChCs/DNA nanopolyplexes were approximately 300 nm and indicated a positive charge. The morphology of these nanopolyplexes was found to be in a spherical shape which was investigated by using the transmission electron microscopy (TEM). The M4-PyMeChC/DNA nanopolyplexes showed highest in vitro transfection efficiency in Huh7 cells at N/P ratio of 20 compared to M2-PyMeChC/DNA and M3-PyMeChC/DNA nanopolyplexes. In comparison to M3-PyMeChC/DNA nanopolyplexes, M2-PyMeChC/DNA and M4-PyMeChC/DNA nanopolyplexes showed lower cytotoxicity in Huh7 cells. Our result demonstrated that N-pyridinium positions of M-PyMeChCs are related to transfection efficiency and cytotoxicity.


Asunto(s)
Quitosano/análogos & derivados , Transfección/métodos , Línea Celular Tumoral , Quitosano/química , Quitosano/toxicidad , Proteínas Fluorescentes Verdes/genética , Humanos , Plásmidos/genética
18.
Mater Sci Eng C Mater Biol Appl ; 33(3): 1727-36, 2013 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-23827630

RESUMEN

Magnesium aluminum silicate (MAS), a negatively charged clay, and nicotine (NCT), a basic drug, can interact electrostatically to form microparticles. Chitosan (CS) was used for the surface modification of the microparticles, and a lyophilization method was used to preserve the original particle morphology. The microparticles were characterized in terms of their physicochemical properties, NCT content, mucoadhesive properties, and release and permeation across porcine esophageal mucosa. The results showed that the microparticles formed via electrostatic interaction between MAS and protonated NCT had an irregular shape and that their NCT content increased with increasing NCT ratios in the microparticle preparation solution. High molecular weight CS (800 kDa) adsorbed to the microparticle surface and induced a positive surface charge. CS molecules intercalated into the MAS silicate layers and decreased the crystallinity of the microparticles, leading to an increase in the release rate and diffusion coefficient of NCT from the microparticles. Moreover, the microparticle surface modified with CS was found to have higher NCT permeation fluxes and mucoadhesive properties, which indicated the significant role of CS for NCT mucosal delivery. However, the enhancement of NCT permeation and of mucoadhesive properties depended on the molecular weight and concentration of CS. These findings suggest that NCT-MAS microparticle surface modified with CS represents a promising mucosal delivery system for NCT.


Asunto(s)
Compuestos de Aluminio/química , Quitosano/química , Sistemas de Liberación de Medicamentos , Compuestos de Magnesio/química , Microesferas , Nicotina/administración & dosificación , Nicotina/farmacología , Silicatos/química , Adhesividad/efectos de los fármacos , Administración a través de la Mucosa , Animales , Rastreo Diferencial de Calorimetría , Concentración de Iones de Hidrógeno , Técnicas In Vitro , Tamaño de la Partícula , Permeabilidad/efectos de los fármacos , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , Propiedades de Superficie , Sus scrofa , Difracción de Rayos X
19.
Eur J Pharm Sci ; 50(3-4): 303-11, 2013 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-23896171

RESUMEN

The production of pharmaceutical nanoparticles by the spinning disk processing (SDP) technique has advantages in terms of its scalability and its capacity to produce readily tunable nanoparticles of narrow size distribution. In this study, we successfully developed a novel multiple stepwise SDP technique to develop aggregates of uniformly sized poly(methyl acrylates)-coated chitosan-diclofenac sodium nanocores (CS-PMA NPs) for colonic drug delivery. The processing conditions were optimized using the Box-Behnken design. SEM and TEM micrographs showed the optimized system to consist of 10 µm-sized agglomerates of CS-PMA NPs, the latter measuring 10nm in diameter. High drug entrapment of 88% was attained. Potential colon-targeted drug release from the CS-PMA NPs was demonstrated, with retardation of drug release in simulated gastrointestinal fluids and over 90% of the drug load released into simulated colonic fluid within 8 h. Drug uptake from CS-PMA NPs into Caco-2 cells was threefold higher than that from a control drug solution, with no apparent cytotoxicity observed at the NP doses administered. The collective data suggest that the SDP is a robust manufacturing method that can potentially be used to scale up the production of composite nanoparticulate colon-targeted drug delivery systems.


Asunto(s)
Antiinflamatorios no Esteroideos/química , Quitosano/química , Diclofenaco/química , Nanopartículas/química , Ácidos Polimetacrílicos/química , Tecnología Farmacéutica/métodos , Antiinflamatorios no Esteroideos/administración & dosificación , Células CACO-2 , Colon/metabolismo , Diclofenaco/administración & dosificación , Humanos , Nanopartículas/administración & dosificación , Tamaño de la Partícula
20.
Int J Biol Macromol ; 55: 24-31, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23298850

RESUMEN

The objective of this study was to prepare and characterize chitosan-magnesium aluminum silicate (CS-MAS) nanocomposite films as a buccal delivery system for nicotine (NCT). The effects of the CS-MAS ratio on the physicochemical properties, release and permeation, as well as on the mucoadhesive properties, were investigated. Molecular interactions between the components of the film were also investigated. The results indicated that NCT-loaded CS-MAS films provided a higher NCT content than NCT-loaded films containing only CS. The greater the MAS ratio in the films, the higher the NCT content that was observed because intercalated nanocomposites could be formed by electrostatic interactions of MAS with NCT and CS. These interactions caused an insignificant loss of NCT by evaporation during film drying. The release and permeation of NCT were related to the square root of time, indicating that a diffusion-controlled mechanism via the NCT-MAS complex particles and the film matrix controls NCT release. NCT release and permeation rates decreased with as the MAS ratio of the films was increased. However, the NCT-loaded CS-MAS films may have a potential adhesion to the mucosal membrane. These findings suggest that NCT-loaded CS-MAS films can be used as a buccal NCT delivery system.


Asunto(s)
Silicatos de Aluminio/química , Quitosano/química , Magnesio/química , Mucosa Bucal/metabolismo , Nanocompuestos/química , Nicotina/administración & dosificación , Compuestos de Aluminio , Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Compuestos de Magnesio , Nanocompuestos/ultraestructura , Nicotina/química , Silicatos , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie
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