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1.
Saudi Pharm J ; 28(6): 719-728, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32550804

RESUMO

Present study explores native L-asparaginase encapsulated long-acting cross-linker-free PLGA-nanoformulation in an Ehrlich ascites tumor model. L-asparaginase-PLGA nanoparticles for tumor were prepared using a double emulsion solvent evaporation technique, optimized and validated by Box-Behnken Design. L-ASN-PNs showed a particle size of 195 nm ± 0.2 nm and a PDI of 0.2. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques revealed its smooth morphology and elicited an in-vitro release of 80% of the drug, following the Higuchi drug release model. In-vivo studies of L-ASN-PNs on an Ehrlich ascites tumor (EAT) model were completed and compared with the standard medication of 5-fluorouracil (5-FU) treatment. L-ASN-PN treated mice showed a 51.15% decrease in tumor volume and 100% survival rate with no reduction in body weight, no haemotoxicity and no hepatotoxicity, as evident from the hematological parameters, and liver enzyme parameters that were well within the prescribed limits. Chemotherapy has severe side effects and restricted therapeutic success. Henceforth, the purported L-Asparaginase PLGA nanoparticles are a suitable entity for better tumor regression, intra-tumor accumulation and no hematological side-effects.

2.
AAPS PharmSciTech ; 18(6): 2188-2202, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28070848

RESUMO

Polyphenon 60 (P60) and curcumin (CUR) were loaded in a single nanoemulsion system and their combined antibacterial action was studied against uropathogenic Escherichia coli. To enhance availability at target organs and to inhibit enzymatic degradation in gastro intestinal tract, vaginal route of administration was explored. P60 + CUR nanoemulsion (NE) was formulated by ultra-sonication and optimized using Box-Behnken design. Optimized NE showed Z-average of 211.2 nm, polydispersity index of 0.343, and zeta potential of -32.7 mV. Optimized P60+ CUR NE was characterized by stability testing and transmission electron microscopy, and it was observed that NE was stable at 4°C for 30 days and monodisperse in nature with particle size of 195-205 nm. P60+ CUR NE was further formulated as gel and characterized by viscosity, growth curve analysis, and in vitro permeation studies. In vitro drug permeation studies in simulated vaginal media showed maximum permeation (84 ± 0.21%) of curcumin within 5 h and (91 ± 0.16%) of P60 within 8 h. Both the drugs maintained sustained permeation for 12 h. To investigate the transport via intravaginal route, gamma scintigraphy and biodistribution study of P60 + CUR NBG was performed on Sprague-Dawley rats using 99mtechnetium pertechnetate for radiolabeling to P60 molecule. Following intravaginal administration, P60 + CUR NBG dispersed in the kidney and urinary bladder with (3.07 ± 0.15) and (3.35 ± 0.45) percentage per gram after 3 h for P60 and CUR, respectively, and remained active for 12 h. Scintigraphy images suggested that the P60 + CUR NBG given by intravaginal route led to effective distribution of actives in urinary tract, and this observation was in agreement with the biodistribution results.


Assuntos
Curcumina , Nanopartículas/uso terapêutico , Fenóis , Administração Intravaginal , Animais , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/farmacocinética , Curcumina/administração & dosagem , Curcumina/farmacocinética , Modelos Animais de Doenças , Portadores de Fármacos , Emulsões , Infecções por Escherichia coli/tratamento farmacológico , Masculino , Tamanho da Partícula , Fenóis/administração & dosagem , Fenóis/farmacocinética , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual , Resultado do Tratamento
3.
Microb Cell Fact ; 14: 41, 2015 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-25889252

RESUMO

Formation of inclusion bodies in bacterial hosts poses a major challenge for large scale recovery of bioactive proteins. The process of obtaining bioactive protein from inclusion bodies is labor intensive and the yields of recombinant protein are often low. Here we review the developments in the field that are targeted at improving the yield, as well as quality of the recombinant protein by optimizing the individual steps of the process, especially solubilization of the inclusion bodies and refolding of the solubilized protein. Mild solubilization methods have been discussed which are based on the understanding of the fact that protein molecules in inclusion body aggregates have native-like structure. These methods solubilize the inclusion body aggregates while preserving the native-like protein structure. Subsequent protein refolding and purification results in high recovery of bioactive protein. Other parameters which influence the overall recovery of bioactive protein from inclusion bodies have also been discussed. A schematic model describing the utility of mild solubilization methods for high throughput recovery of bioactive protein has also been presented.


Assuntos
Escherichia coli/metabolismo , Corpos de Inclusão/metabolismo , Redobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Escherichia coli/genética , Modelos Moleculares , Desnaturação Proteica , Dobramento de Proteína , Desdobramento de Proteína , Solubilidade
4.
Phytochem Anal ; 26(2): 97-104, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25469471

RESUMO

INTRODUCTION: Gymnema sylvestre is an important anti-diabetic medicinal plant, hence it is necessary to study the effective extraction of its active medicinal components. OBJECTIVE: To develop an efficient ultrasound-assisted extraction method for anti-diabetic gymnemic acids from Gymnema sylvestre leaves and measure their effect on insulin-producing RINm-5 F ß cells. METHODS: Box-Behnken's design and response surface methodology was applied to the ultrasound-assisted extraction of gymnemic acids from Gymnema sylvestre leaves. Analysis of gymnemic acids was carried out by high-performance thin-layer chromatography by converting total gymnemic acids into gymnemagenin by alkali hydrolysis. Effects of extracts on insulin production were tested on cultured, insulin-producing RINm-5 F ß cell lines. RESULTS: The point prediction tool of the design expert software predicted 397.9 mg gymnemic acids per gram of the defatted G. sylvestre leaves using ultrasound-assisted extraction, with ethanol at 60 °C for 30 min. The predicted condition shows 93.34% validity under experimental conditions. The ultrasound-assisted extract caused up to about four times more insulin production from RINm-5 F ß cells than extracts obtained from Soxhlet extraction. CONCLUSIONS: Response surface methodology was successfully used to improve the extraction of gymnemic acids from G. sylvestre leaves. The ultrasound-assisted extraction process may be a better alternative to prepare such herbal extracts because it saves time and may prevent excess degradation of the target analytes.


Assuntos
Alcaloides/farmacologia , Gymnema sylvestre/química , Extratos Vegetais/farmacologia , Saponinas/farmacologia , Triterpenos/farmacologia , Alcaloides/química , Alcaloides/isolamento & purificação , Linhagem Celular , Gymnema sylvestre/ultraestrutura , Hidrólise , Insulina/metabolismo , Microscopia Eletrônica de Varredura , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Folhas de Planta/ultraestrutura , Plantas Medicinais , Saponinas/química , Saponinas/isolamento & purificação , Triterpenos/química , Triterpenos/isolamento & purificação , Ultrassom
5.
Mol Pharm ; 11(3): 922-37, 2014 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-24446810

RESUMO

Bacterial capsular polysaccharides are components of many modern vaccines, but they are weakly immunogenic. Herein, we describe the delivery of pneumococcal capsular polysaccharide serotype-1 (PCP-1) in polylactide polymeric particles to enhance its immunogenicity. Immunization with PCP-1-entrapped particles elicited long-term memory antibody responses from a single intramuscular injection. PCP-1-entrapped nanoparticles (NPs) elicited significantly higher anti-PCP-1 IgG responses than that observed with soluble and microparticles (MPs) formulations. Delivering PCP-1 and pneumococcal proteins in same particles did not improve the IgG response. The sera of animals immunized with PCP-1-entrapped particles promoted efficient opsonophagocytosis of pneumococci by macrophages. Single-dose immunization with PCP-1-entrapped particles conferred a long-term serotype-specific protection against lethal pneumococcal challenge. The higher immunogenicity of PCP-1 nanoparticles showed correlation with enhanced uptake by antigen-presenting cells. The results highlight the potential of polymeric nanoparticles as an efficient means of presenting polysaccharide antigens to the immune system.


Assuntos
Nanopartículas/administração & dosagem , Proteínas Opsonizantes/metabolismo , Fagocitose/fisiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/administração & dosagem , Polímeros/química , Polissacarídeos Bacterianos/administração & dosagem , Polissacarídeos Bacterianos/imunologia , Animais , Formação de Anticorpos/imunologia , Células Apresentadoras de Antígenos/imunologia , Células Cultivadas , Feminino , Imunização , Macrófagos/citologia , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/microbiologia , Vacinas Pneumocócicas/imunologia
6.
Artigo em Inglês | MEDLINE | ID: mdl-38347431

RESUMO

Chemotherapy and immunotherapy are two important modalities in cancer management. However, due to multiple reasons, a monotherapy is only partially effective. Hence, if used concurrently in targeted and stimuli-responsive manner, it could have been superior therapeutically. To facilitate co-delivery of chemotherapeutic and immunotherapeutic agent to the target cancer cells, engineered nanoparticles, i.e., a pH-responsive polymer PLGA-coated magnetic silica nanoparticles (Fe3O4-SiO2-PLGA-PDA-PTX-siRNA NPs) encapsulating paclitaxel (PTX) and siRNA against programmed cell death ligand-1 (PD-L1) are synthesized and characterized. Developed nanoparticles demonstrated pH-sensitive sustained drug release up to 10 days. In vitro 4T1 cell line studies showed efficient cellular uptake, PD-L1 gene downregulation, and apoptosis. Further, in vivo efficacy studies carried out in the mice model demonstrated a significant reduction of tumor growth following treatment with dual-Fe3O4-SiO2-PLGA-PDA-PTX-siRNA NPs as compared with monotherapy with Fe3O4-SiO2-PLGA-PDA-PTX NPs. The high therapeutic efficacy observed with dual-Fe3O4-SiO2-PLGA-PDA-PTX-siRNA NPs was mainly due to the cytotoxic effect of PTX combined with targeted silencing of the gene of interest, i.e., PD-L1, which in turn improve CD8+ T cell-mediated cancer cell death as evident with increased proliferation of CD8+ T cells in co-culture experiments. Thereby, dual-Fe3O4-SiO2-PLGA-PDA-PTX-siRNA NPs may have a promising anti-cancer treatment potential against breast cancer; however, the beneficial effects of dual loading of PTX + PD-L1 siRNA may be corroborated against other cancer models such as lung and colorectal cancer models as well as in clinical trials.

7.
Sci Rep ; 14(1): 12935, 2024 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839973

RESUMO

The inhibition of tumor necrosis factor (TNF)-α trimer formation renders it inactive for binding to its receptors, thus mitigating the vicious cycle of inflammation. We designed a peptide (PIYLGGVFQ) that simulates a sequence strand of human TNFα monomer using a series of in silico methods, such as active site finding (Acsite), protein-protein interaction (PPI), docking studies (GOLD and Flex-X) followed by molecular dynamics (MD) simulation studies. The MD studies confirmed the intermolecular interaction of the peptide with the TNFα. Fluorescence-activated cell sorting and fluorescence microscopy revealed that the peptide effectively inhibited the binding of TNF to the cell surface receptors. The cell culture assays showed that the peptide significantly inhibited the TNFα-mediated cell death. In addition, the nuclear translocation of the nuclear factor kappa B (NFκB) was significantly suppressed in the peptide-treated A549 cells, as observed in immunofluorescence and gel mobility-shift assays. Furthermore, the peptide protected against joint damage in the collagen-induced arthritis (CIA) mouse model, as revealed in the micro focal-CT scans. In conclusion, this TNFα antagonist would be helpful for the prevention and repair of inflammatory bone destruction and subsequent loss in the mouse model of CIA as well as human rheumatoid arthritis (RA) patients. This calls upon further clinical investigation to utilize its potential effect as an antiarthritic drug.


Assuntos
Peptídeos , Fator de Necrose Tumoral alfa , Humanos , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Animais , Camundongos , Peptídeos/farmacologia , Peptídeos/química , Artrite Experimental/tratamento farmacológico , Artrite Experimental/metabolismo , Artrite Experimental/patologia , Simulação de Acoplamento Molecular , Células A549 , Simulação de Dinâmica Molecular , NF-kappa B/metabolismo , NF-kappa B/antagonistas & inibidores , Masculino , Antirreumáticos/farmacologia , Antirreumáticos/química , Antirreumáticos/uso terapêutico , Ligação Proteica , Modelos Animais de Doenças
8.
Vaccine ; 41(50): 7515-7524, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-37980259

RESUMO

Streptococcus pneumoniae having almost 98 serotypes and being common cause of acute otitis media, pneumonia, bacteremia, meningitis etc., which results in high mortality and morbidity globally. Although vaccines like PCV-13 and PPV-23 are available, some problems like serotype replacement and poor immunogenicity in children, old age and immunocompromised people has been observed. To overcome these drawbacks protein/peptide-based vaccine can be a good strategy as these provides wide serotype coverage. However, immunogenicity of protein subunit vaccines is lower, that issue can be solved by using adjuvants. Recently nanoparticles as an adjuvant for vaccine delivery being used, which has provided not only good immunogenicity but also improved delivery and efficiency of protein-based vaccines. In this review we have discussed the latest advancement of nanoparticles-based protein/peptide vaccine delivery for Streptococcus pneumoniae.


Assuntos
Otite Média , Infecções Pneumocócicas , Criança , Humanos , Streptococcus pneumoniae , Peptídeos , Vacinas Pneumocócicas , Sorogrupo , Otite Média/prevenção & controle , Polissacarídeos , Vacinas Conjugadas , Infecções Pneumocócicas/prevenção & controle
9.
Eur J Pharm Biopharm ; 176: 43-53, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35589003

RESUMO

Nanoparticles-based multivalent antigen display has the capability of mimicking natural virus infection characteristics, making it useful for eliciting potent long-lasting immune response. Several vaccines are developed against global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However these subunit vaccines use mammalian expression system, hence mass production with rapid pace is a bigger challenge. In contrast E. coli based subunit vaccine production circumvents these limitations. The objective of the present investigation was to develop nanoparticle vaccine with multivalent display of receptor binding domain (RBD) of SARS-CoV-2 expressed in E. coli. Results showed that RBD entrapped PLA (Poly lactic acid) nanoparticle in combination with aluminum hydroxide elicited 9-fold higher immune responses as compared to RBD adsorbed aluminum hydroxide, a common adjuvant used for human immunization. It was interesting to note that RBD entrapped PLA nanoparticle with aluminum hydroxide not only generated robust and long-lasting antibody response but also provided Th1 and Th2 balanced immune response. Moreover, challenge with 1 µg of RBD alone was able to generate secondary antibody response, suggesting that immunization with RBD-PLA nanoparticles has the ability to elicit memory antibody against RBD. Plaque assay revealed that the antibody generated using the polymeric formulation was able to neutralize SARS-CoV-2. The RBD entrapped PLA nanoparticles blended with aluminum hydroxide thus has potential to develop asa subunit vaccine against COVID-19.


Assuntos
COVID-19 , Nanopartículas , Hidróxido de Alumínio , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Formação de Anticorpos , Vacinas contra COVID-19 , Escherichia coli , Humanos , Mamíferos , Nanopartículas/química , Poliésteres , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Vacinas de Subunidades Antigênicas
10.
Front Cell Dev Biol ; 10: 845457, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35433699

RESUMO

Troxerutin (TXR) is a phytochemical reported to possess anti-inflammatory and hepatoprotective effects. In this study, we aimed to exploit the antiarthritic properties of TXR using an adjuvant-induced arthritic (AIA) rat model. AIA-induced rats showed the highest arthritis score at the disease onset and by oral administration of TXR (50, 100, and 200 mg/kg body weight), reduced to basal level in a dose-dependent manner. Isobaric tags for relative and absolute quantitative (iTRAQ) proteomics tool were employed to identify deregulated joint homogenate proteins in AIA and TXR-treated rats to decipher the probable mechanism of TXR action in arthritis. iTRAQ analysis identified a set of 434 proteins with 65 deregulated proteins (log2 case/control≥1.5) in AIA. Expressions of a set of important proteins (AAT, T-kininogen, vimentin, desmin, and nucleophosmin) that could classify AIA from the healthy ones were validated using Western blot analysis. The Western blot data corroborated proteomics findings. In silico protein-protein interaction study of tissue-proteome revealed that complement component 9 (C9), the major building blocks of the membrane attack complex (MAC) responsible for sterile inflammation, get perturbed in AIA. Our dosimetry study suggests that a TXR dose of 200 mg/kg body weight for 15 days is sufficient to bring the arthritis score to basal levels in AIA rats. We have shown the importance of TXR as an antiarthritic agent in the AIA model and after additional investigation, its arthritic ameliorating properties could be exploited for clinical usability.

11.
Biomater Sci ; 9(23): 7962-7976, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34704986

RESUMO

Phagocytosis of particulate vaccine delivery systems is a critical immune mechanism involved in antigen capture and processing by macrophages and dendritic cells. The internalization and degradation of the particles involve a complex sequence of events. This process coordinates lipids, signaling proteins, and the cytoskeleton. Dynamic changes in the actin cytoskeleton are essential for phagocytosis and antigen presentation. Knowledge regarding the correlation of surface properties, attached ligand density and geometric size of particles with the efficiency of phagocytosis may facilitate their design and application. To investigate this, polylactide biodegradable particles with different diameters (2-4 µm and 200-300 nm) were exposed to murine macrophages and dendritic cells and the effect of size on a series of cellular responses was evaluated. Cellular uptake studies using microscopy and flow cytometry showed size dependent internalization of particles, with nanoparticles accumulating in cells at a faster rate. The particles induced homoaggregation of cells and also showed cytoskeletal remodeling that could be inhibited by cytochalasin-D. Scanning electron microscopy images showed the time dependent formation of phagocytic cups and invaginations that promote particle uptake. The particles were observed to co-localized with the endo-lysosomal compartments after phagocyotosis. In our experiments, particle mediated immunoactivation, antigen processing and cytokine secretion have shown a good correlation with the uptake process. These findings would allow a better understanding of the process of particle uptake and may be instrumental in the rational design of optimal vaccine delivery systems.


Assuntos
Citoesqueleto , Fagocitose , Animais , Células Apresentadoras de Antígenos , Camundongos , Tamanho da Partícula , Poliésteres
12.
Protein Pept Lett ; 28(2): 122-130, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32729411

RESUMO

Escherichia coli has been most widely used for production of the recombinant proteins. Over-expression of the recombinant proteins is the mainspring of the inclusion bodies formation. The refolding of these proteins into bioactive forms is cumbersome and partly time-consuming. In the present study, we reviewed and discussed most issues regarding the recovery of "classical inclusion bodies" by focusing on our previous experiences. Performing proper methods of expression, solubilization, refolding and final purification of these proteins, would make it possible to recover higher amounts of proteins into the native form with appropriate conformation. Generally, providing mild conditions and proper refolding buffers, would lead to recover more than 40% of inclusion bodies into bioactive and native conformation.


Assuntos
Escherichia coli/metabolismo , Corpos de Inclusão/metabolismo , Engenharia de Proteínas/métodos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Humanos , Dobramento de Proteína , Proteínas Recombinantes/isolamento & purificação , Solubilidade
13.
Eur J Pharm Biopharm ; 152: 270-281, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32470636

RESUMO

Polysaccharide antigens do not promote antibody class switching and memory antibody response, thus require conjugation with a T cell dependent carrier protein to generate protective immune response. The intensity of immune responses varies with the carrier proteins for the same carbohydrate antigen and most of the carrier proteins do not generate strong immune responses. Vi polysaccharide and r-flagellin of Salmonella typhi were conjugated and formulated in PLA particles as nanoglycoconjugate which not only generated strong immune response but also promoted antibody class switching and elicited memory antibody response from single point immunization. Nanoglycoconjugate immunization also modulate anti-inflammatory property of Vi polysaccharide with an enhance secretion of pro-inflammatory cytokine TNF-α and IL-6. This was with concomitant decrease of IFN-γ production, antibody class switching from IgG3 to IgG2 with memory antibody generation against Vi polysaccharide. Antibody elicited by nanoglycoconjugate showed better opsonization and clearance of Salmonella typhi in THP-1 macrophages as compared to Vi-flagellin glycoconjugate and Vi TT (Typhbar®). Delivery of glycoconjugate through nanoparticles provides a platform technology for improving the immunogenicity of polysaccharide based vaccines.


Assuntos
Glicoconjugados/imunologia , Imunidade/imunologia , Nanopartículas/química , Poliésteres/química , Polissacarídeos Bacterianos/imunologia , Salmonella typhi/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Formação de Anticorpos/imunologia , Antígenos/imunologia , Linhagem Celular , Feminino , Imunização/métodos , Imunoglobulina G/imunologia , Interleucina-6/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Células RAW 264.7 , Fator de Necrose Tumoral alfa/imunologia , Vacinas Tíficas-Paratíficas/imunologia , Vacinação/métodos , Vacinas Conjugadas/imunologia
14.
Int J Biol Macromol ; 163: 1240-1248, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32668306

RESUMO

SP0845, a pneumococcal surface protein and a potential candidate vaccine for Streptococcus pneumoniae infection, was used to evaluate the role of histidine affinity tag on its biophysical properties and immunogenicity. The protein was expressed in E. coli with and without histidine affinity tag and purified to homogeneity. Size exclusion chromatographic studies revealed that tag free SP0845 was mainly monomeric in solution whereas, histidine tagged SP0845 stayed predominantly in an oligomeric form. Histidine-tagged SP0845 have higher ß sheet content than the tag free protein. Removal of histidine tag increased the α-helical content of SP0845 from 35% to 46%. Histidine tagged SP0845 elicited higher serum antibody titer in comparison to the tag free SP0845 in mice. Effect of alum in improving the immunogenicity of tagged SP0845 was low in comparison to that observed with tag free protein. Immunogenicity of tag free SP0845 was enhanced by delivering it using polylactide polymeric particles. The presence of histidine tag thus influences the secondary structure and immunogenicity of protein and need careful consideration before use.


Assuntos
Anticorpos/metabolismo , Formação de Anticorpos/fisiologia , Proteínas de Bactérias/metabolismo , Histidina/metabolismo , Proteínas de Membrana/metabolismo , Streptococcus pneumoniae/metabolismo , Animais , Escherichia coli/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Secundária de Proteína
16.
J Pharm Sci ; 96(11): 3010-23, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17588259

RESUMO

The present study describes the fabrication of insulin loaded chitosan succinate microspheres to improve the efficacy of orally administered insulin. Chitosan succinate polymer was synthesized and its microspheres were prepared by emulsion phase separation technique. The microspheres were characterized by FT-IR spectroscopy, scanning electron microscopy, particle size, X-ray diffraction, and swelling index. Insulin was loaded into the microspheres by passive absorption technique. The ability of microspheres to protect insulin from gastric enzymatic degradation was investigated. Stability of insulin in the microspheres was determined by gel electrophoresis and circular dichroism (CD). In vitro release studies were performed under simulated gastric and intestinal pH conditions (pH 2.0 and pH 7.4). The pharmacokinetic parameters were monitored after oral administration of insulin loaded chitosan succinate microspheres, chitosan succinate-insulin solution, as well as after subcutaneous injection of insulin to diabetic rats. The degree of succinate substitution in the synthesized polymer was 16%. The prepared microspheres were spherical with an average diameter of 49 +/- 2 microm. The insulin-loading capacity was 62%. Chitosan succinate microspheres were found to protect the degradation of insulin from gastric enzymes. The encapsulated insulin was quickly released in simulated intestinal fluid (SIF, pH 7.4), whereas a small fraction of insulin was released in simulated gastric fluid (pH 2.0). The relative pharmacological efficacy for chitosan succinate microspheres (16 +/- 4%) was almost fourfold higher than the efficacy of the chitosan succinate-insulin solution administration (4 +/- 1.5%). The results suggest that chitosan succinate microspheres could be used as a potential carrier for oral insulin delivery.


Assuntos
Quitosana/administração & dosagem , Quitosana/química , Insulina/administração & dosagem , Insulina/química , Administração Oral , Animais , Disponibilidade Biológica , Glicemia/efeitos dos fármacos , Varredura Diferencial de Calorimetria , Quitosana/síntese química , Quitosana/farmacocinética , Dicroísmo Circular , Preparações de Ação Retardada , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Insulina/farmacocinética , Masculino , Microscopia Eletrônica de Varredura , Microesferas , Ratos , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier , Termografia
17.
J Pharm Pharmacol ; 59(10): 1345-51, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17910808

RESUMO

Novel chitosan phthalate microspheres containing insulin were prepared by emulsion cross-linking technique. The feasibility of these microspheres as oral insulin delivery carriers was evaluated. The pH-responsive release behaviour of insulin from microspheres was analysed. The ability of chitosan phthalate-insulin microspheres to enhance intestinal absorption and improve the relative pharmacological availability of insulin was investigated by monitoring the plasma glucose and insulin level of streptozotocin-induced diabetic rats after oral administration of microspheres at insulin dose of 20 IU kg(-1). In simulated gastric fluid (pH 2.0), insulin release from the microspheres was very slow. However, as the pH of the medium was changed to simulated intestinal fluid (pH 7.4), a rapid release of insulin occurred. The relative pharmacological efficacy for chitosan phthalate microspheres (18.66 +/- 3.84%) was almost four-fold higher than the efficacy of the chitosan phthalate-insulin solution administration (4.08 +/- 1.52%). Chitosan phthalate microspheres sustained the plasma glucose at pre-diabetic level for at least 16 h. These findings suggest that the microsphere is a promising carrier as oral insulin delivery system.


Assuntos
Quitosana/química , Diabetes Mellitus Experimental/tratamento farmacológico , Portadores de Fármacos/química , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Administração Oral , Animais , Glicemia/efeitos dos fármacos , Reagentes de Ligações Cruzadas , Preparações de Ação Retardada , Emulsões , Suco Gástrico/metabolismo , Concentração de Íons de Hidrogênio , Hipoglicemiantes/farmacologia , Insulina/metabolismo , Insulina/farmacologia , Absorção Intestinal , Secreções Intestinais/metabolismo , Masculino , Microesferas , Tamanho da Partícula , Ratos , Ratos Wistar , Estreptozocina
18.
Eur J Pharm Sci ; 101: 125-139, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28189815

RESUMO

It is imperative to interrupt the link between arthritis and regulation of oxidative stress with the administration of antioxidants. Suramin is known for its anti-inflammatory, antineoplastic and antiangiogenic activities implying its possible antioxidant property. In this study, the antioxidant activity of suramin in cell free system was found to be higher than l-ascorbic acid (l-AA) with respect to its scavenging effect on nitric oxide (NO), hypochlorous acid and hydrogen peroxide radicals. Besides, suramin was found to be nontoxic to cultured RAW cells even at high concentrations along with marked inhibition of NO production. Suramin was found to curb the inflammation associated with the collagen induced arthritis (CIA) model. Administration of suramin significantly reduced the malondialdehyde and protein carbonyl content in joints, liver, kidney and spleen of rats as studied ex vivo. Furthermore, the increased antioxidant enzymes such as SOD, catalase, GST, GPx and GR activities in the tissues were restored significantly after suramin treatment. In silico experiments using Vlife MDS4.4-GRIP docking method showed strong affinity of suramin towards erythrocyte catalase followed by glutathione peroxidase thus corroborating with the findings of antioxidant enzyme assays. Our studies clearly indicate that suramin has remarkable antioxidant potential and can ameliorate arthritis via modulation of oxidative stress.


Assuntos
Antioxidantes/farmacologia , Artrite Experimental/induzido quimicamente , Artrite Experimental/tratamento farmacológico , Colágeno/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Suramina/farmacologia , Animais , Artrite Experimental/metabolismo , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Linhagem Celular , Feminino , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Camundongos , Óxido Nítrico/metabolismo , Oxirredução/efeitos dos fármacos , Carbonilação Proteica/efeitos dos fármacos , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo
19.
Sci Rep ; 7(1): 10062, 2017 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-28855623

RESUMO

Curcumin has many pharmacological activities despite its poor bioavailability and in vivo stability. Here, we show that a nanoformulated curcumin (PLGA-curcumin) has better therapeutic index than native curcumin in preventing the onset of neurological symptoms and delaying the death of mice in experimental cerebral malaria. Oral PLGA-curcumin was at least as effective as native curcumin at a 15-fold lower concentration in preventing the breakdown of blood-brain barrier and inhibition of brain mRNAs for inflammatory cytokines, chemokine receptor CXCR3 and its ligand CXCL10, with an increase in the anti-inflammatory cytokine IL-10. This was also reflected in serum cytokine and chemokine levels. At equivalent concentrations, a single oral dose of PLGA-curcumin was more effective in inhibiting serum IFNγ levels and enhancing IL-10 levels than native curcumin. Even at low concentrations, PLGA-curcumin was superior to native curcumin in inhibiting the sequestration of parasitized-RBCs and CD8+ T cells in the brain. A single oral dose of 5 mg PLGA-curcumin containing 350 µg of curcumin resulted in 3-4 fold higher concentration and prolonged presence of curcumin in the brain than that obtained with 5 mg of native curcumin, indicating better bioavailability of PLGA-curcumin. PLGA-curcumin has potential as an adjunct drug to treat human cerebral malaria.


Assuntos
Antimaláricos/farmacologia , Encéfalo/efeitos dos fármacos , Curcumina/farmacologia , Malária Cerebral/tratamento farmacológico , Nanopartículas/administração & dosagem , Fármacos Neuroprotetores/farmacologia , Animais , Antimaláricos/química , Disponibilidade Biológica , Encéfalo/parasitologia , Encéfalo/patologia , Linfócitos T CD8-Positivos , Quimiocina CXCL10/genética , Quimiocina CXCL10/imunologia , Curcumina/química , Modelos Animais de Doenças , Portadores de Fármacos , Composição de Medicamentos/métodos , Eritrócitos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interferon gama/genética , Interferon gama/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Malária Cerebral/genética , Malária Cerebral/parasitologia , Malária Cerebral/patologia , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Nanopartículas/metabolismo , Fármacos Neuroprotetores/química , Plasmodium berghei/efeitos dos fármacos , Plasmodium berghei/crescimento & desenvolvimento , Plasmodium berghei/patogenicidade , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Receptores CXCR3/genética , Receptores CXCR3/imunologia , Transdução de Sinais
20.
Drug Deliv ; 23(2): 500-11, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-24937381

RESUMO

A receptor level interaction of etoposide with P-glycoprotein (P-gp) and subsequent intestinal efflux has an adverse effect on its oral absorption. The present work is aimed to enhance the bioavailability of etoposide by co-administering it with quercetin (a P-gp inhibitor) in dual-loaded polymeric nanoparticle formulation. Poly-lactic-co-glycolic acid (PLGA) nanoparticles were optimized for various parameters like o/w phase volume ratio, poly-vinyl alcohol concentration, PLGA concentration and sonication time. The cytotoxicity studies (MTT assay) revealed a 9- and 11-fold decrease in the IC 50 values for etoposide-loaded nanoparticles (ENP) and etoposide + quercetin dual-loaded nanoparticles (EQNP) when compared to that of free etoposide, respectively, and the results were further supported by florescent-activated cell sorter studies. The confocal imaging of the intestinal sections treated with ENP and EQNP containing fluorescent probe (rhodamine) showed the superiority of the EQNP to permeate deeper. Furthermore, pharmacokinetic studies on rats revealed that EQNP exhibited a 2.4-fold increase in bioavailability of etoposide than ENP with no quercetin. The developed loaded nanoparticles have the high potential to enhance the bioavailability of the etoposide and sensitize the resistant cells.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Portadores de Fármacos , Etoposídeo/administração & dosagem , Absorção Intestinal/efeitos dos fármacos , Ácido Láctico/química , Nanopartículas , Ácido Poliglicólico/química , Quercetina/administração & dosagem , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Administração Oral , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacocinética , Disponibilidade Biológica , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Separação Celular/métodos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Composição de Medicamentos , Etoposídeo/química , Etoposídeo/farmacocinética , Feminino , Citometria de Fluxo , Corantes Fluorescentes/metabolismo , Humanos , Concentração Inibidora 50 , Células MCF-7 , Masculino , Microscopia Confocal , Nanotecnologia , Permeabilidade , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Álcool de Polivinil/química , Quercetina/química , Ratos Wistar , Rodaminas/metabolismo , Solubilidade , Sonicação , Tecnologia Farmacêutica/métodos
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