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1.
Drug Dev Res ; 80(6): 807-813, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31294492

RESUMO

Neutropenia is a condition of an abnormally low number of neutrophils which render patients more susceptible to infections, especially to bacterial infections, as the condition may become life threatening and deadly without prompt medical attention. Various factors such as, anticancer drugs, radiotherapy, infectious diseases, congenital defects, or vitamin B12/B9 deficiency can trigger neutropenia. GX-G3, a human hybrid (hy) Fc-fused granulocyte colony stimulating factor (G-CSF), was developed as next-generation G-CSF for the treatment of cancer therapy-induced neutropenia. In this study, with the aim of investigating this promising potential next-generation G-CSF, comparative pharmacokinetic and pharmacodynamic studies were conducted in healthy and neutropenia-induced rats. It was found that t1/2 of GX-G3 is longer than same mass injection of filgrastim and pegfilgrastim and AUEClast (area under theeffect-time curve from time zero to the last measurable ANC level) of absolute neutrophil count showed a significant increase after GX-G3 injection compared with filgrastim and pegfilgrastim in healthy rats. Besides, in duration of neutropenia after the same mass injection GX-G3 showed about 3.3 days of reduction effect compared with that of filgrastim, and 1.3 days of reduction effect compared with that of pegfilgrastim in neutropenia-induced rats. These results demonstrate that the half-life of GX-G3 is longer than pegfilgrastim and GX-G3 is more effective than filgrastim and pegfilgrastim in neutropenia-induced rats.


Assuntos
Fator Estimulador de Colônias de Granulócitos/farmacologia , Fator Estimulador de Colônias de Granulócitos/farmacocinética , Neutropenia/imunologia , Neutropenia/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Proteínas Recombinantes de Fusão/farmacocinética , Animais , Meia-Vida , Injeções Subcutâneas , Contagem de Leucócitos , Masculino , Neutrófilos/efeitos dos fármacos , Ratos
2.
J Microencapsul ; 34(7): 659-666, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28862080

RESUMO

The blood-brain barrier (BBB) is the major problem for the treatment of central nervous system diseases. A previous study from our group showed that the brain-targeted chitosan nanoparticles-loaded with large peptide moieties can rapidly cross the barrier and provide neuroprotection. The present study aims to determine the efficacy of the brain-targeted chitosan nanoparticles' uptake by the human BBB cerebral microvessel endothelial cells (hCMECs) and to investigate the underlying mechanisms for enhanced cellular entry. Fluorescently labelled nanoparticles either conjugated with antibodies recognising human transferrin receptor (anti-TfR mAb) or not were prepared, characterised and their interaction with cerebral endothelial cells was evaluated. The antibody decoration of chitosan nanoparticles significantly increased their entry into hCMEC/D3 cell line. Inhibition of cellular uptake by chlorpromazine indicated that the anti-TfR mAb-conjugated nanoparticles were preferentially cell internalised through receptor-mediated endocytosis pathway. Alternatively, as primarily observed with control chitosan nanoparticles, aggregation of nanoparticles may also have induced macropinocytosis.


Assuntos
Barreira Hematoencefálica , Encéfalo/efeitos dos fármacos , Circulação Cerebrovascular , Quitosana/administração & dosagem , Microvasos/efeitos dos fármacos , Nanopartículas , Anticorpos Monoclonais/imunologia , Corantes Fluorescentes , Humanos , Microvasos/metabolismo , Receptores da Transferrina/imunologia , Receptores da Transferrina/metabolismo
3.
Acta Pol Pharm ; 74(2): 357-367, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29624240

RESUMO

New analytical methods have been developed and validated on high performance liquid chromatography (HPLC) to assess the assay, content uniformity and dissolution of immediate release candesartan cilexetil 32 mg tablets. Method development studies were performed on cyano column. Mobile phase of assay and content uniformity test consisted of mixture of 0.05 M phosphate buffer, pH 4.5 and methanol (40 : 60, v/v) adjusted to pH 4.0 with trifluoroacetic acid, whereas mobile phase of dissolution test consisted of mixture of I mM phosphate buffer and acetonitrile (50 : 50, v/v) adjusted to pH 2.0 with trifluoroacetic acid. Mobile phases were pumped at flow rate of 1.0 mL/min, ultraviolet-visible (UV) detector was operated at 254 nm, injection volume was set at 20 µL, column temperature was held at 25°C. Dissolution medium was 0.05 M phosphate buffer, pH 6.5 including 0.70% (w/v) polysorbate 20. Validation studies met acceptance criteria of system suitability, specificity, linearity and range, accuracy, precision, detection limit (LOD), quantitation limit (LOQ) and robustness parameters.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/isolamento & purificação , Benzimidazóis/análise , Compostos de Bifenilo/análise , Cromatografia Líquida de Alta Pressão , Tetrazóis/análise , Bloqueadores do Receptor Tipo 1 de Angiotensina II/química , Benzimidazóis/química , Compostos de Bifenilo/química , Soluções Tampão , Química Farmacêutica , Composição de Medicamentos , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Solubilidade , Solventes/química , Comprimidos , Temperatura , Tetrazóis/química
4.
J Drug Target ; : 1-10, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38946465

RESUMO

Overexpression of permeability-glycoprotein (P-gp) transporter leads to multidrug resistance (MDR) through cellular exclusion of chemotherapeutics. Co-administration of P-gp inhibitors and chemotherapeutics is a promising approach for improving the efficacy of therapy. Nevertheless, problems in pharmacokinetics, toxicity and solubility limit the application of P-gp inhibitors. Herein, we developed a novel all-in-one hybrid nanoparticle system to overcome MDR in doxorubicin (DOX)-resistant breast cancer. First, folic acid-modified DOX-loaded mesoporous silica nanoparticles (MSNs) were prepared and then loaded into PEGylated poly(lactic-co-glycolic acid) (PLGA) nanoparticles along with a P-gp inhibitor, elacridar. This hybrid nanoparticle system had high drug loading capacity, enabled both passive and active targeting of tumour tissues, and exhibited sequential and pH-triggered release of drugs. In vitro and in vivo studies in DOX-resistant breast cancer demonstrated the ability of the hybrid nanoparticles to reverse P-gp-mediated drug resistance. The nanoparticles were efficiently taken up by the breast cancer cells and delivered elacridar, in vitro. Biodistribution studies demonstrated substantial accumulation of the folate receptor-targeted PLGA/MSN hybrid nanoparticles in tumour-bearing mice. Moreover, deceleration of the tumour growth was remarkable in the animals administered with the DOX and elacridar co-loaded hybrid nanoparticles when compared to those treated with the marketed liposomal DOX (Caelyx®) or its combination with elacridar.

5.
Pharmaceutics ; 14(8)2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-36015197

RESUMO

Avastin® is a humanized recombinant monoclonal antibody used to treat cancer by targeting VEGF-A to inhibit angiogenesis. SIMAB054, an Avastin® biosimilar candidate developed in this study, showed a different charge variant profile than its innovator. Thus, it is fractionated into acidic, main, and basic isoforms and collected physically by Cation Exchange Chromatography (CEX) for a comprehensive structural and functional analysis. The innovator product, fractionated into the same species and collected by the same method, is used as a reference for comparative analysis. Ultra-Performance Liquid Chromatography (UPLC) ESI-QToF was used to analyze the modifications leading to charge heterogeneities at intact protein and peptide levels. The C-terminal lysine clipping and glycosylation profiles of the samples were monitored by intact mAb analysis. The post-translational modifications, including oxidation, deamidation, and N-terminal pyroglutamic acid formation, were determined by peptide mapping analysis in the selected signal peptides. The relative binding affinities of the fractionated charge isoforms against the antigen, VEGF-A, and the neonatal receptor, FcRn, were revealed by Surface Plasmon Resonance (SPR) studies. The results show that all CEX fractions from the innovator product and the SIMAB054 shared the same structural variants, albeit in different ratios. Common glycoforms and post-translational modifications were the same, but at different percentages for some samples. The dissimilarities were mostly originating from the presence of extra C-term Lysin residues, which are prone to enzymatic degradation in the body, and thus they were previously assessed as clinically irrelevant. Another critical finding was the presence of different glyco proteoforms in different charge species, such as increased galactosylation in the acidic and afucosylation in the basic species. SPR characterization of the isolated charge variants further confirmed that basic species found in the CEX analyses of the biosimilar candidate were also present in the innovator product, although at lower amounts. The charge variants' in vitro antigen- and neonatal receptor-binding activities varied amongst the samples, which could be further investigated in vivo with a larger sample set to reveal the impact on the pharmacokinetics of drug candidates. Minor structural differences may explain antigen-binding differences in the isolated charge variants, which is a key parameter in a comparability exercise. Consequently, such a biosimilar candidate may not comply with high regulatory standards unless the binding differences observed are justified and demonstrated not to have any clinical impact.

6.
Acta Pol Pharm ; 68(3): 423-33, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21648198

RESUMO

In the present study, the possible interactions between celecoxib and some excipients (colloidal silicon dioxide (Aerosil), microcrystalline cellulose (Avicel PH 102), lactose anhydrous, magnesium stearate, cross-povidone and talc) were evaluated by examining the pure drug or drug-excipient powder mixtures which were stored under different conditions (25 +/- 2 degrees C, 60% RH +/- 5% RH or 40 + 2 degrees C, 75% RH +/- 5% RH) and different period (30 or 60 days) using DSC, FT-IR and HPLC. In order to investigate the possibility of celecoxib-excipient interaction in aqueous medium, dispersions of the pure drug or drug in physical powder mixture (1:1 w/w) in water (1%, w/v) were also prepared and evaluated by FT-IR and HPLC at day 0 and day 7 (40 +/- 2 degrees C). The interaction between celecoxib and magnesium stearate or colloidal silicon dioxide were determined in the aqueous dispersions by FT-IR. Different tablet formulations with or without excipients tested were prepared, and assessed for drug dissolution and permeability.


Assuntos
Inibidores de Ciclo-Oxigenase 2/química , Excipientes/química , Pirazóis/química , Sulfonamidas/química , Células CACO-2 , Varredura Diferencial de Calorimetria , Celecoxib , Celulose/química , Química Farmacêutica , Cromatografia Líquida de Alta Pressão , Inibidores de Ciclo-Oxigenase 2/metabolismo , Composição de Medicamentos , Estabilidade de Medicamentos , Humanos , Umidade , Absorção Intestinal , Mucosa Intestinal/metabolismo , Lactose/química , Permeabilidade , Povidona/química , Pirazóis/metabolismo , Dióxido de Silício/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Ácidos Esteáricos/química , Sulfonamidas/metabolismo , Comprimidos , Talco/química , Tecnologia Farmacêutica/métodos , Temperatura , Fatores de Tempo
7.
Anal Chim Acta ; 1152: 238189, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33648647

RESUMO

The similarity between originator and biosimilar monoclonal antibody candidates are rigorously assessed based on primary, secondary, tertiary, quaternary structures, and biological functions. Minor differences in such parameters may alter target-binding, potency, efficacy, or half-life of the molecule. The charge heterogeneity analysis is a prerequisite for all biotherapeutics. Monoclonal antibodies are prone to enzymatic or non-enzymatic structural modifications during or after the production processes, leading to the formation of fragments or aggregates, various glycoforms, oxidized, deamidated, and other degraded residues, reduced Fab region binding activity or altered FcR binding activity. Therefore, the charge variant profiles of the monoclonal antibodies must be regularly and thoroughly evaluated. Comparative structural and functional analysis of physically separated or fractioned charged variants of monoclonal antibodies has gained significant attention in the last few years. The fraction-based charge variant analysis has proved very useful for the biosimilar candidates comprising of unexpected charge isoforms. In this report, the key methods for the physical separation of monoclonal antibody charge variants, structural and functional analyses by liquid chromatography-mass spectrometry, and surface plasmon resonance techniques were reviewed.


Assuntos
Medicamentos Biossimilares , Anticorpos Monoclonais , Cromatografia Líquida , Espectrometria de Massas , Ressonância de Plasmônio de Superfície
8.
J Neurosci ; 29(44): 13761-9, 2009 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-19889988

RESUMO

Caspases play an important role as mediators of cell death in acute and chronic neurological disorders. Although peptide inhibitors of caspases provide neuroprotection, they have to be administered intracerebroventricularly because they cannot cross the blood-brain barrier (BBB). Herein, we present a nanocarrier system that can transfer chitosan nanospheres loaded with N-benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-fluoromethyl ketone (Z-DEVD-FMK), a relatively specific caspase-3 inhibitor, across BBB. Caspase-3 was chosen as a pharmacological target because of its central role in cell death. Polyethylene glycol-coated nanospheres were conjugated to an anti-mouse transferrin receptor monoclonal antibody (TfRMAb) that selectively recognizes the TfR type 1 on the cerebral vasculature. We demonstrate with intravital microscopy that this nanomedicine is rapidly transported across the BBB without being measurably taken up by liver and spleen. Pre- or post-treatment (2 h) with intravenously injected Z-DEVD-FMK-loaded nanospheres dose dependently decreased the infarct volume, neurological deficit, and ischemia-induced caspase-3 activity in mice subjected to 2 h of MCA occlusion and 24 h of reperfusion, suggesting that they released an amount of peptide sufficient to inhibit caspase activity. Similarly, nanospheres inhibited physiological caspase-3 activity during development in the neonatal mouse cerebellum on postnatal day 17 after closure of the BBB. Neither nanospheres functionalized with TfRMAb but not loaded with Z-DEVD-FMK nor nanospheres lacking TfRMAb but loaded with Z-DEVD-FMK had any effect on either paradigm, suggesting that inhibition of caspase activity and subsequent neuroprotection were due to efficient penetration of the peptide into brain. Thus, chitosan nanospheres open new and exciting opportunities for brain delivery of biologically active peptides that are useful for the treatment of CNS disorders.


Assuntos
Barreira Hematoencefálica/metabolismo , Inibidores de Caspase , Inibidores de Cisteína Proteinase/metabolismo , Nanomedicina/métodos , Fármacos Neuroprotetores/metabolismo , Peptídeos/metabolismo , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Isquemia Encefálica/patologia , Isquemia Encefálica/prevenção & controle , Caspase 3/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Inibidores de Cisteína Proteinase/uso terapêutico , Camundongos , Nanosferas , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Oligopeptídeos/metabolismo , Oligopeptídeos/farmacologia , Oligopeptídeos/uso terapêutico , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Transporte Proteico/fisiologia , Ratos
9.
Int J Pharm ; 578: 119076, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31988035

RESUMO

Malignant gliomas are highly lethal. Delivering chemotherapeutic drugs to the brain in sufficient concentration is the major limitation in their treatment due to the blood-brain barrier (BBB). Drug delivery systems may overcome this limitation and can improve the transportation through the BBB. Paclitaxel is an antimicrotubule agent with effective anticancer activity but limited BBB permeability. R-Flurbiprofen is a nonsteroidal antienflammatory drug and has potential anticancer activity. Accordingly, we designed an approach combining R-flurbiprofen and paclitaxel and positively-charged chitosan-modified poly-lactide-co-glycolic acid (PLGA) nanoparticles (NPs) and to transport them to glioma tissue. NPs were characterized and, cytotoxicity and cellular uptake studies were carried out in vitro. The in vivo efficacy of the combination and formulations were evaluated using a rat RG2 glioma tumor model. Polyethylene glycol (PEG) modified and chitosan-coated PLGA NPs demonstrated efficient cytotoxic activity and were internalized by the tumor cells in RG2 cell culture. In vivo studies showed that the chitosan-coated and PEGylated NPs loaded with paclitaxel and R-flurbiprofen exhibited significantly higher therapeutic activity against glioma. In conclusion, PLGA NPs can efficiently carry their payloads to glioma tissue and the combined use of anticancer and anti-inflammatory drugs may exert additional anti-tumor activity.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Antineoplásicos/administração & dosagem , Flurbiprofeno/administração & dosagem , Glioblastoma/tratamento farmacológico , Nanopartículas/administração & dosagem , Paclitaxel/administração & dosagem , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/administração & dosagem , Animais , Anti-Inflamatórios não Esteroides/química , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Combinação de Medicamentos , Liberação Controlada de Fármacos , Feminino , Flurbiprofeno/química , Nanopartículas/química , Paclitaxel/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Ratos Wistar , Carga Tumoral/efeitos dos fármacos
10.
AAPS PharmSciTech ; 9(4): 1191-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19082740

RESUMO

This study was performed to prepare and characterize the biotinylated Salmon calcitonin (sCT) for oral delivery and evaluate the hypocalcemic effect of biotinylated-sCTs in rats. Biotinylated sCTs was characterized by using high performance liquid chromatography (HPLC) and MALDITOF-MS. The effect of biotinylation on permeability across Caco-2 cell monolayers was examined. Their hypocalcemic effect was determined in rats. Mono- and di-bio-sCTs were separated by reverse phase HPLC. The molecular weights of mono-bio-sCT and di-bio-sCT were determined to be 3,660.5 and 3,900.2 Da, respectively. The permeability of biotinylated-sCTs across Caco-2 cell monolayers was observed with a significant enhancement compared with sCT. Intrajejunal (ij) administration of mono-bio-sCT and di-bio-sCT resulted in sustained reduction in serum calcium levels, with a maximum reduction (% max(d)) of 21.6% and 30% after 4 h and 6 h of application, respectively. The biotin conjugation of sCT may be a promising strategy for increasing the oral bioavailability of sCT and achieving sustained calcium-lowering effects.


Assuntos
Biotina/química , Calcitonina/química , Administração Oral , Sequência de Aminoácidos , Animais , Biotina/administração & dosagem , Células CACO-2 , Calcitonina/administração & dosagem , Cromatografia Líquida de Alta Pressão , Humanos , Masculino , Dados de Sequência Molecular , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
11.
Methods Mol Biol ; 1727: 443-454, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29222804

RESUMO

Here, we describe a nanocarrier system that can transfer chitosan nanoparticles loaded with either small peptides such as the caspase inhibitor Z-DEVD-FMK or a large peptide like basic fibroblast growth factor across the blood-brain barrier. The nanoparticles are selectively directed to the brain and are not measurably taken up by the liver and spleen. Intravital fluorescent microscopy provides an opportunity to study the penetration kinetics of nanoparticles loaded with fluorescent agents such as Nile red. Nanoparticles functionalized with anti-transferrin antibody and loaded with peptides efficiently provided neuroprotection when systemically administered either as a formulation bearing a single peptide or a mixture of them. Failure of brain permeation of the nanoparticles after inhibition of vesicular transcytosis by imatinib as well as when nanoparticles were not functionalized with anti-transferrin antibody indicates that this nanomedicine formulation is rapidly transported across the blood-brain barrier by receptor-mediated transcytosis.


Assuntos
Materiais Biocompatíveis/química , Quitosana/química , Peptídeos/farmacocinética , Animais , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/ultraestrutura , Microscopia Intravital , Camundongos , Nanopartículas/química , Peptídeos/química , Transcitose
12.
Drug Deliv ; 14(8): 525-9, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18027182

RESUMO

The objective of our study was to prepare and characterize basic fibroblast growth factor (bFGF)-loaded nanoparticles. Protein-loaded chitosan nanoparticles were obtained by ionotropic gelation process based on the interaction between chitosan and tripolyphosphate (TPP). The protein-loading capacity and encapsulation efficiency were 0.021% and 27.388%, respectively. The bFGF-loaded nanoparticles have a mean diameter of 424 nm, a narrow size distribution, spherical shape and positive surface charges. In vitro release showed that the extent of release was 68% at 24 hr. The protein integrity was investigated by SDS-PAGE analysis that confirmed protein integrity was not affected by the encapsulation procedure and release conditions.


Assuntos
Quitosana/química , Sistemas de Liberação de Medicamentos/métodos , Fator 2 de Crescimento de Fibroblastos/administração & dosagem , Nanopartículas/química , Preparações de Ação Retardada/química , Estabilidade de Medicamentos , Fator 2 de Crescimento de Fibroblastos/farmacocinética , Microscopia de Força Atômica , Tamanho da Partícula , Polifosfatos/química , Eletricidade Estática , Propriedades de Superfície
13.
AAPS PharmSciTech ; 8(1): 26, 2007 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-17408225

RESUMO

The objective of this study was to characterize the stability of KSL-W, an antimicrobial decapeptide shown to inhibit the growth of oral bacterial strains associated with caries development and plaque formation, and its potential as an antiplaque agent in a chewing gum formulation. KSL-W formulations with or without the commercial antibacterial agent cetylpyridinium chloride (CPC) were prepared. The release of KSL-W from the gums was assessed in vitro using a chewing gum apparatus and in vivo by a chew-out method. A reverse-phase high-performance liquid chromatography method was developed for assaying KSL-W. Raw material stability and temperature and pH effects on the stability of KSL-W solutions and interactions of KSL-W with tooth-like material, hydroxyapatite discs, were investigated. KSL-W was most stable in acidic aqueous solutions and underwent rapid hydrolysis in base. It was stable to enzymatic degradation in human saliva for 1 hour but was degraded by pancreatic serine proteases. KSL-W readily adsorbed to hydroxyapatite, suggesting that it will also adsorb to the teeth when delivered to the oral cavity. The inclusion of CPC caused a large increase in the rate and extent of KSL-W released from the gums. The gum formulations displayed promising in vitro/in vivo release profiles, wherein as much as 90% of the KSL-W was released in a sustained manner within 30 minutes in vivo. These results suggest that KSL-W possesses the stability, adsorption, and release characteristics necessary for local delivery to the oral cavity in a chewing gum formulation, thereby serving as a novel antiplaque agent.


Assuntos
Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/química , Goma de Mascar , Preparações de Ação Retardada/química , Placa Dentária/prevenção & controle , Excipientes/química , Saliva/química , Administração Oral , Antibacterianos/administração & dosagem , Antibacterianos/química , Difusão , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos , Humanos , Teste de Materiais
14.
Artif Cells Nanomed Biotechnol ; 45(8): 1657-1664, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28084837

RESUMO

In this study, it was aimed to investigate characteristics and intracellular delivery of two different-sized PLGA nanoparticles in ouzo region by considering number of nanoparticles. To determine the effect of formulation parameters on average particle size, Dil labeled nanoparticles were prepared using a three-factor, two-level full factorial statistical experimental design. PLGA230 (230.8 ± 4.32 nm) and PLGA160 (157.9 ± 6.16 nm) nanoparticles were obtained by altering polymer amount based on experimental design results and characterized. Same number of PLGA230 and PLGA160 nanoparticles per cell were applied onto HEK293 cells; then, cytotoxicity, uptake kinetics and mechanism were evaluated by flow cytometry and fluorescent microscopy. Also same weight of PLGA230 and PLGA160 nanoparticles were applied and cellular uptake of these nanoparticles was evaluated. It was found that PLGA230 nanoparticles had higher encapsulation efficiency and slower dye release compared to PLGA160 nanoparticles. When they were applied at same counts per cell, PLGA230 nanoparticles displayed faster and higher intracellular dye transfer than PLGA160 nanoparticles. On the other hand, PLGA160 appeared to be a more effective vehicle than PLGA230 when applied at the same weight concentration. It was also shown that for both nanoparticles, HEK293 cells employed macropinocytic, caveolae- and clathrin-mediated endocytic pathways.


Assuntos
Precipitação Química , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Espaço Intracelular/metabolismo , Ácido Láctico/química , Ácido Láctico/metabolismo , Tamanho da Partícula , Ácido Poliglicólico/química , Ácido Poliglicólico/metabolismo , Transporte Biológico , Células HEK293 , Humanos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
15.
J Control Release ; 107(1): 122-30, 2005 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-16009443

RESUMO

The purpose of this study was to investigate the potential of KSL, an antimicrobial decapeptide, which has been shown to inhibit the growth of oral bacterial strains associated with caries development and plaque formation, to act as an antiplaque agent in a chewing gum formulation. A reversed-phase high-performance liquid chromatography method was developed for KSL and found to be stability-indicating. KSL was stable in acetate buffer at pH 4 and artificial saliva. On the affinity of KSL to tooth-like materials, the KSL showed favorable interaction with hydroxyapatite discs pretreated with human saliva. A chewing gum formulation of KSL was prepared based on conventional procedures and the release of KSL from the gum was studied in vitro using the chewing apparatus and in vivo by a chew-out method. The gum formulations showed promising in vitro/in vivo release profiles, in which 70-80% KSL was released in a sustained manner over 20 min of chewing time. This study suggests that KSL in a gum formulation is suitable for the delivery in the oral cavity, thereby serving as a novel antiplaque agent.


Assuntos
Antibacterianos/farmacologia , Goma de Mascar , Preparações de Ação Retardada/farmacologia , Placa Dentária/prevenção & controle , Depsipeptídeos/análise , Antibacterianos/farmacocinética , Cromatografia Líquida de Alta Pressão , Preparações de Ação Retardada/farmacocinética , Sistemas de Liberação de Medicamentos , Estabilidade de Medicamentos , Humanos , Concentração de Íons de Hidrogênio , Hidroxiapatitas/química , Saliva/química , Saliva/metabolismo , Temperatura , Fatores de Tempo , Água/química
16.
Int J Pharm ; 298(2): 378-83, 2005 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-15893439

RESUMO

The aim of this work was to develop a formulation for Z-DEVD-FMK, a peptide which is a caspase inhibitor and has been used in experimental animal studies for a decade. Peptide loaded chitosan nanoparticles were obtained by ionotropic gelation process and Z-DEVD-FMK was quantified by an HPLC method. The influence of the initial peptide concentration on the nanoparticle characteristics and release behavior was evaluated. The CS nanoparticles have a particle diameter (Z-average) ranging from approximately 313-412 nm and a positive zeta potential (20-28 mV). The formulation with the initial peptide concentration of 400 ng/ml provided the highest loading capacity (0.46%) and the highest extent of release (65% at 24 h) suggesting the possibility to achieve a therapeutic dose. According to the data obtained, this chitosan-based nanotechnology opens new and interesting perspectives for anticaspase activity.


Assuntos
Inibidores de Caspase , Quitosana/química , Nanoestruturas , Oligopeptídeos/administração & dosagem , Inibidores de Proteases/administração & dosagem , Fenômenos Químicos , Físico-Química , Cromatografia Líquida de Alta Pressão , Eletroquímica , Géis , Microscopia Eletrônica de Transmissão , Oligopeptídeos/química , Tamanho da Partícula , Inibidores de Proteases/química
17.
J Cereb Blood Flow Metab ; 35(3): 469-75, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25492116

RESUMO

Although growth factors and anti-apoptotic peptides have been shown to be neuroprotective in stroke models, translation of these experimental findings to clinic is hampered by limited penetration of peptides to the brain. Here, we show that a large peptide like the basic fibroblast growth factor (bFGF) and a small peptide inhibitor of caspase-3 (z-DEVD-FMK) can effectively be transported to the brain after systemic administration by incorporating these peptides to brain-targeted nanoparticles (NPs). Chitosan NPs were loaded with peptides and then functionalized by conjugating with antibodies directed against the transferrin receptor-1 on brain endothelia to induce receptor-mediated transcytosis across the blood-brain barrier (BBB). Pre-ischemic systemic administration of bFGF- or z-DEVD-FMK-loaded NPs significantly decreased the infarct volume after 2-hour middle cerebral artery occlusion and 22-hour reperfusion in mice. Co-administration of bFGF- or z-DEVD-FMK-loaded NPs reduced the infarct volume further and provided a 3-hour therapeutic window. bFGF-loaded NPs were histologically detected in the brain parenchyma and also restored ischemia-induced Akt dephosphorylation. The neuroprotection was not observed when receptor-mediated transcytosis was inhibited with imatinib or when bFGF-loaded NPs were not conjugated with the targeting antibody, which enables them to cross the BBB. Nanoparticles targeted to brain are promising drug carriers to transport large as well as small BBB-impermeable therapeutics for neuroprotection against stroke.


Assuntos
Fator 2 de Crescimento de Fibroblastos/administração & dosagem , Nanoconjugados/administração & dosagem , Fármacos Neuroprotetores/administração & dosagem , Oligopeptídeos/administração & dosagem , Acidente Vascular Cerebral/patologia , Animais , Barreira Hematoencefálica , Masculino , Camundongos
18.
AAPS PharmSciTech ; 4(2): E28, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12916910

RESUMO

The purpose of this research was to assess the physicochemical properties of a controlled release formulation of recombinant human growth hormone (rHGH) encapsulated in poly(D,L-lactide-co-glycolide) (PLGA) composite microspheres. rHGH was loaded in poly(acryloyl hydroxyethyl) starch (acHES) microparticles, and then the protein-containing microparticles were encapsulated in the PLGA matrix by a solvent extraction/evaporation method. rHGH-loaded PLGA microspheres were also prepared using mannitol without the starch hydrogel microparticle microspheres for comparison. The detection of secondary structure changes in protein was investigated by using a Fourier Transfer Infrared (FTIR) technique. The composite microspheres were spherical in shape (44.6 +/- 2.47 microm), and the PLGA-mannitol microspheres were 39.7 +/- 2.50 microm. Drug-loading efficiency varied from 93.2% to 104%. The composite microspheres showed higher overall drug release than the PLGA/mannitol microspheres. FTIR analyses indicated good stability and structural integrity of HGH localized in the microspheres. The PLGA-acHES composite microsphere system could be useful for the controlled delivery of protein drugs.


Assuntos
Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Hormônio do Crescimento Humano/administração & dosagem , Microesferas , Ácido Poliglicólico/química , Portadores de Fármacos , Hormônio do Crescimento Humano/química , Humanos , Conformação Proteica , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
19.
Nat Nanotechnol ; 9(12): 1054-1062, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25420034

RESUMO

There is an urgent need to develop new therapeutic approaches for the treatment of severe neurological trauma, such as stroke and spinal cord injuries. However, many drugs with potential neuropharmacological activity, such as adenosine, are inefficient upon systemic administration because of their fast metabolization and rapid clearance from the bloodstream. Here, we show that conjugation of adenosine to the lipid squalene and the subsequent formation of nanoassemblies allows prolonged circulation of this nucleoside, providing neuroprotection in mouse stroke and rat spinal cord injury models. The animals receiving systemic administration of squalenoyl adenosine nanoassemblies showed a significant improvement of their neurologic deficit score in the case of cerebral ischaemia, and an early motor recovery of the hindlimbs in the case of spinal cord injury. Moreover, in vitro and in vivo studies demonstrated that the nanoassemblies were able to extend adenosine circulation and its interaction with the neurovascular unit. This Article shows, for the first time, that a hydrophilic and rapidly metabolized molecule such as adenosine may become pharmacologically efficient owing to a single conjugation with the lipid squalene.

20.
J Pharm Sci ; 102(10): 3748-61, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23918313

RESUMO

The aims of this study were to develop and characterize paclitaxel nanoparticles, to identify and control critical sources of variability in the process, and to understand the impact of formulation and process parameters on the critical quality attributes (CQAs) using a quality-by-design (QbD) approach. For this, a risk assessment study was performed with various formulation and process parameters to determine their impact on CQAs of nanoparticles, which were determined to be average particle size, zeta potential, and encapsulation efficiency. Potential risk factors were identified using an Ishikawa diagram and screened by Plackett-Burman design and finally nanoparticles were optimized using Box-Behnken design. The optimized formulation was further characterized by Fourier transform infrared spectroscopy, X-ray diffractometry, differential scanning calorimetry, scanning electron microscopy, atomic force microscopy, and gas chromatography. It was observed that paclitaxel transformed from crystalline state to amorphous state while totally encapsulating into the nanoparticles. The nanoparticles were spherical, smooth, and homogenous with no dichloromethane residue. In vitro cytotoxicity test showed that the developed nanoparticles are more efficient than free paclitaxel in terms of antitumor activity (more than 25%). In conclusion, this study demonstrated that understanding formulation and process parameters with the philosophy of QbD is useful for the optimization of complex drug delivery systems.


Assuntos
Nanopartículas/química , Paclitaxel/química , Antineoplásicos/química , Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos/métodos , Tamanho da Partícula
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