Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Int J Biol Macromol ; 253(Pt 2): 126652, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37673169

RESUMO

Channelopathies arise from ion channel dysfunction. Successful treatment entails delivery of functional ion channels to replace dysfunctional ones. Glycine receptor (GlyR)-rich cell membrane fragments (CMF) were previously delivered to target cell membranes using fusogenic liposomes. Here, cystic fibrosis transmembrane conductance regulator (CFTR)-bearing CMF were similarly delivered to target cells. We studied the effect of lipid composition on liposomes' ability to incorporate CMF and fuse with target cell membranes to deliver functional CFTR. Four formulations were prepared using thin-film hydration out of different lecithin sources, egg and soy lecithin (EL and SL), in the presence and absence of cholesterol (CHOL): EL + CHOL, EL-CHOL, SL + CHOL, and SL-CHOL. EL liposomes incorporated more CMF than SL liposomes, with CHOL only increasing CMF incorporation in SL liposomes. SL + CHOL fused better with target cell membranes than EL + CHOL. SL + CHOL and EL + CHOL equally delivered CFTR to target cell membranes, owing to the former's superior fusogenic capacity and the latter's superior CMF-incorporation capacity. SL-CHOL and EL-CHOL delivered CFTR to a lesser extent, indicating the importance of CHOL for fusion. Patch-clamp electrophysiology and confocal laser scanning microscopy (CLSM) confirmed CFTR delivery to target cell membranes by SL + CHOL. Therefore, CMF-bearing fusogenic liposomes offer a promising universal platform for the treatment of channelopathies.


Assuntos
Canalopatias , Fibrose Cística , Humanos , Lipossomos , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/tratamento farmacológico , Lecitinas , Canalopatias/tratamento farmacológico
2.
Eur J Pharm Biopharm ; 184: 16-24, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36640916

RESUMO

Alzheimer's disease (AD) is the most common type of dementia. Increasing evidence is showing the important role of mitochondrial dysfunction in AD. Mitochondria based oxidative stress, decrease in respiratory chain activity and ATP production are all associated with AD, hence indicating that the enhancement of mitochondrial function and biogenesis present a promising therapeutic approach for AD. Nitric oxide (NO) is an initiator of mitochondrial biogenesis. However, its gaseous nature and very short half-life limit the realization of its therapeutic potential. Additionally, its uncontrolled in-vivo distribution results in generalized vasodilation, hypotension among other off-target effects. Diazeniumdiolates (NONOates) are NO donors that release NO in physiological temperature and pH. Their encapsulation within a hydrophobic matrix carrier system could control the release of NO, and at the same time enable its delivery to the brain. In this work, PAPANONOate (PN) a NO donor was encapsulated in small (92 ± 7 nm) poly (lactic-co-glycolic acid) (PLGA) NPs. These NPs did not induce hemolysis upon intravenous administration and were able to accumulate in the brains of lipopolysaccharides (LPS) induced neurodegeneration mouse models. The encapsulation of PN within a hydrophobic PLGA matrix enabled the sustained release of NO from NPs (≈ 3 folds slower relative to free PN) and successfully delivered PN to brain. As a result, PN-NPs but not free PN resulted in an enhancement in memory and cognition in animals with neurodegeneration as determined by the Y-maze test. The enhancement in cognition was a result of increased mitochondria function as indicated by the increased production of ATP and Cytochrome C oxidase enzyme activity.


Assuntos
Doença de Alzheimer , Nanopartículas , Camundongos , Animais , Doença de Alzheimer/tratamento farmacológico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Óxido Nítrico , Ácido Poliglicólico/química , Ácido Láctico/química , Nanopartículas/química , Mitocôndrias , Trifosfato de Adenosina
3.
Biomed Mater ; 18(1)2022 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-36541457

RESUMO

Metabolic reprogramming 'Warburg effect' and immune checkpoint signaling are immunosuppressive hallmarks of triple-negative breast cancer (TNBC) contributing to the limited clinical applicability of immunotherapy. Biomaterials arise as novel tools for immunomodulation of the tumor microenvironment that can be used alongside conventional immunotherapeutics. Chitosan and lecithin are examples of versatile biomaterials with interesting immunomodulatory properties. In this study, we aimed at investigation of the role of carefully designed hybrid nanoparticles (NPs) on common mediators of both programmed death ligand 1 (PD-L1) expression and glycolytic metabolism. Hybrid lecithin-chitosan NPs were prepared and characterized. Their intracellular concentration, localization and effect on the viability of MDA-MB-231 cells were assessed. Glycolytic metabolism was quantified by measuring glucose consumption, adenosine triphosphate (ATP) generation, lactate production and extracellular acidification. Nitric oxide production was quantified using Greiss reagent. Gene expression of inducible nitric oxide synthase (iNOS), phosphatidylinositol-3-kinase (PI3K), protein kinase B (PKB or Akt), mammalian target of rapamycin (mTOR), hypoxia-inducible factor 1α(HIF-1α) and PD-L1 was quantified by quantitative reverse transcription polymerase chain reaction (q-RT-PCR). Chitosan, lecithin and the NPs-formulated forms have been shown to influence the 'Warburg effect' and immune checkpoint signaling of TNBC cells differently. The composition of the hybrid systems dictated their subcellular localization and hence the positive or negative impact on the immunosuppressive characteristics of TNBC cells. Carefully engineered hybrid lecithin-chitosan NPs could convert the immune-suppressive microenvironment of TNBC to an immune-active microenvironment via reduction of PD-L1 expression and reversal of the Warburg effect.


Assuntos
Quitosana , Nanopartículas , Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/terapia , Neoplasias de Mama Triplo Negativas/genética , Antígeno B7-H1 , Lecitinas , Materiais Biocompatíveis , Microambiente Tumoral
4.
Pain Physician ; 25(8): 555-567, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36375185

RESUMO

BACKGROUND: An impaired immune system in the perioperative period has important clinical implications in patients with cancer. Despite the immunosuppressive properties of opioid therapy, it is still commonly utilized in the intrathecal or epidural space for the treatment of postoperative pain. Also, intrathecal dexmedetomidine has extended analgesic efficacy in postoperative pain; it can significantly affect immune function in perioperative patients. OBJECTIVE: To investigate the effect of intrathecal morphine, dexmedetomidine, or both in combination with bupivacaine on cellular immunity and cytokine production in cancer surgical patients. STUDY DESIGN: A prospective randomized clinical study. SETTING: South Egypt Cancer Institute, Assiut University. METHODS: Ninety patients were randomly assigned to receive intrathecal morphine 0.5 mg (Group M, n = 30), dexmedetomidine 0.5 µg/kg (Group D, n = 30) or morphine 0.5 mg with dexmedetomidine 0.5 µg/kg (Group MD n = 30); 2 mL bupivacaine 0.5% was added to injected drugs in all groups.  Blood samples were collected preoperative (T0), immediate postoperative (T1), 4 hours postoperative (T2), and 24 hours postoperative (T3) for measurement of CD3, CD4, CD4/CD8 and CD16+56(NK), interleukin(IL)-1beta (IL-1beta), IL-6, IL-10 and tumor necrosis factor alpha (TNF-alpha). RESULTS: A significant reduction in cellular immunity (CD3, CD4, CD8, CD4/CD8, CD 16+56) was noticed in the 24-hour postoperative period in all 3 studied groups, with a marked reduction in Group M in comparison to Group MD and Group D. Regarding inflammatory mediators, IL-10 and IL-1beta  showed significant reduction in Group M in the first 24-hour postoperative period in comparison to Group MD and Group D, while IL-6 was significantly reduced in Group MD and Group D in comparison to Group M in the same period. TNF-alpha was significantly increased postoperative at T1 and T2 in the 3 studied groups, then at T3 it decreased without a statistically significant difference with the preoperative level. LIMITATIONS: Our study has some limitations, such as the short period of follow-up and lack of postoperative clinical follow-up of patients to discover the association between immunity and patient outcomes. CONCLUSION: Intrathecal dexmedetomidine has the least immunosuppressive effect than morphine and morphine-dexmedetomidine, in combination with bupivacaine.


Assuntos
Neoplasias Abdominais , Dexmedetomidina , Humanos , Bupivacaína/uso terapêutico , Morfina/uso terapêutico , Dexmedetomidina/uso terapêutico , Interleucina-10/uso terapêutico , Estudos Prospectivos , Fator de Necrose Tumoral alfa/uso terapêutico , Interleucina-6/uso terapêutico , Método Duplo-Cego , Dor Pós-Operatória/tratamento farmacológico , Analgésicos Opioides/uso terapêutico , Neoplasias Abdominais/cirurgia , Anestésicos Locais/uso terapêutico
5.
Mediterr J Hematol Infect Dis ; 14(1): e2022022, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35444773

RESUMO

Background: Invasive fungal infections (IFIs) are important cause of mortality in acute myeloid leukemia (AML) patients on treatment with intensive induction chemotherapy. Toll-like receptors, mainly Toll-like receptors 2 and 4 (TLR2 and TLR4), play a considerable role in the host defense against microorganisms. The involvement of TLR signaling in modulation of innate immune response is extensively discussed, but the TLR expressions profiling on adaptive immune cells are not specified. Also, the expressions of TLRs and their association with the occurrence of IFIs in patients with AML are not studied. So, the novel aim of this study was to investigate the associations between the T-lymphocyte expression of TLR2 and TLR4 and the occurrence of IFIs in AML patients treated with intensive induction chemotherapy. Materials and Methods: One hundred twenty two newly diagnosed AML patients were evaluated. The laboratory diagnostic techniques for IFIs include culture, microscopic examination, histopathology, galactomannan assay and PCR. The expressions of TLR2 and TLR4 were analyzed by flow cytometry. The Control group included 20 age and sex-matched individuals. Results: There was a significant increase in the expression of TLR4 in AML patients with IFI compared to healthy controls (p = 0.001). TLR2 and TLR4 expressions increased significantly in AML patients with mixed fungal and bacterial infection compared to healthy controls (p= 0.002 and p=0.001, respectively). Conclusion: TLRs expressions could be important biological markers for the occurrence of IFI in non-M3 AML patients after intensive induction chemotherapy.

6.
Mol Pharm ; 19(5): 1635-1646, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35380849

RESUMO

The nanoparticle (NP) protein corona represents an interface between biological components and NPs, dictating their cellular interaction and biological fate. To assess the success of cellular targeting, NPs modified with targeting ligands are incubated with target cells in serum-free culture medium or in the presence of fetal bovine serum (FBS). In the former, the role of the corona is overlooked, and in the latter, the effects of a corona that does not represent the one forming in humans nor the respective disease state are considered. Via proteomic analysis, we demonstrate how the difference in the composition of FBS, sera from healthy human volunteers, and breast cancer patients (BrCr Pt) results in the formation of completely different protein coronas around the same NP. Successful in vitro targeting of breast cancer cells was only observed when NPs were incubated with target cells in the presence of BrCr Pt sera only. In such cases, the success of targeting was not attributed to the targeting ligand itself, but to the adsorption of specific serum proteins that facilitate NP uptake by cancer cells in the presence of BrCr Pt sera. This work therefore demonstrates how the serum source affects the reliability of in vitro experiments assessing NP-cell interactions and the consequent success or failure of active targeting and may in fact indicate an additional reason for the limited clinical success of drug targeting by NPs in cancer.


Assuntos
Neoplasias da Mama , Quitosana , Nanopartículas , Coroa de Proteína , Neoplasias da Mama/tratamento farmacológico , Feminino , Ácido Fólico , Humanos , Nanopartículas/metabolismo , Coroa de Proteína/metabolismo , Proteômica , Reprodutibilidade dos Testes , Soroalbumina Bovina
7.
Colloids Surf B Biointerfaces ; 211: 112289, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34954516

RESUMO

Due to its overexpression in cancer cells, the folate receptor (FR) is heavily exploited in the active targeting of nanoparticles (NPs). Its ligand, folic acid (FA) is as a consequence widely used as a NP targeting ligand. Although rather popular and successful in principle, recent data has shown that FA may result in breast cancer initiation and progression, which questions the suitability of FA as NP cancer targeting ligand. In this work, intravenous administration of free FA to healthy female mice resulted in breast tissue dysplasia, hyperplasia and in the increased expression of human epidermal growth factor receptor-2 (HER2), folate receptor (FR), cancer antigen 15-3 (CA15.3), vascular endothelial growth factor (VEGF), signal transducer and activator of transcription 3 (STAT3) and the pro-inflammatory cytokines, tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6) and interleukin-1ß. In addition to the reduction in IL2. To evaluate the suitability and safety of FA as NP targeting ligand in breast cancer, small (≈ 150 nm) and large (≈ 500 nm) chitosan NPs were formulated and decorated with two densities of FA. The success of active targeting by FA was confirmed in two breast cancer cell lines (MCF-7 and MDA-MB-231 cells) in comparison to HEK293 cells. FA modified NPs that demonstrated successful active targeting in-vitro were assessed in-vivo. Upon intravenous administration, large NPs modified with a high density of FA accumulated in the breast tissue and resulted in similar effects as those observed with free FA. These results therefore question the suitability of FA as a targeting ligand in breast cancer and shed light on the importance of considering the activity (other than targeting) of the ligands used in NP active targeting.


Assuntos
Neoplasias da Mama , Nanopartículas , Animais , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Feminino , Ácido Fólico/metabolismo , Células HEK293 , Humanos , Ligantes , Camundongos , Fator A de Crescimento do Endotélio Vascular
8.
Int J Hematol ; 110(1): 69-76, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31115879

RESUMO

Monoclonal antibodies against surface antigens on MM cells, such as anti-SLAMF7 and anti-CD38 antibodies, represent an attractive therapeutic modality for the eradication of multiple myeloma (MM) cells. However, further exploration of target molecules is urgently needed for the development of more effective therapies. In the present study, we studied the expression of CD48 in a total of 74 primary MM samples derived from patients to evaluate SLAMF2 (CD48) as a candidate in mAb therapy for MM. Of 74 samples, 39 were subjected to SLAMF7 analysis. Most of the MM cells, defined as CD38 and CD138 double-positive cells, showed strong expression of CD48 or SLAMF7 independent of disease stage or treatment history. In these 39 samples, most MM cells showed expression of both SLAMF7 and CD48; however, several samples showed expression of either only CD48 or only SLAMF7, including seven cases that were only highly positive for SLAMF7, and five that were only highly positive for CD48. Our study demonstrates that the immune receptor CD48 is overexpressed on MM cells together with SLAMF7, and that CD48 may be considered as an alternative target for treatment of MM in cases showing weak expression of SLAMF7.


Assuntos
Mieloma Múltiplo/química , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , ADP-Ribosil Ciclase 1/análise , Anticorpos Monoclonais/uso terapêutico , Antígeno CD48/análise , Antígeno CD48/metabolismo , Humanos , Glicoproteínas de Membrana/análise , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/imunologia , Receptores Imunológicos/imunologia , Família de Moléculas de Sinalização da Ativação Linfocitária/análise , Sindecana-1/análise
9.
Clin J Pain ; 35(4): 328-334, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30829734

RESUMO

OBJECTIVES: Continuous wound infiltration of local anesthetics has been proposed as an alternative to epidural analgesia during abdominal surgery. Cytokines have a major role in inflammatory changes caused by surgery. This study aimed to compare the effects of continuous preperitoneal versus epidural analgesia on inflammatory cytokines postoperatively. MATERIALS AND METHODS: Forty patients scheduled for radical cystectomy were included in this observer-blinded, randomized trial; patients were randomly assigned into 2 groups to receive; continuous preperitoneal wound infiltration (PPB) or epidural analgesia (EDB). Serum levels of interleukins (IL1ß, IL6, IL10, and tumor necrosis factor α) were measured at baseline (before induction of anesthesia), preinfusion (before the start of local anesthetic infusion), 6 and 24 hours postoperatively. Visual Analog Scale at rest/movement (VAS-R/M), time to the first request of analgesia, total morphine consumption, sedation score, hemodynamics, and side effects were observed 24 hours postoperatively. RESULTS: There was a significant reduction in IL6, IL1ß and increase in IL10 in PPB compared with EDB at 6 and 24 hours postoperatively and compared with preinfusion levels (P≤0.001). In EDB, a significant increase in IL1ß, IL10, and tumor necrosis factor α at 6 hours compared with preinfusion levels (P≤0.002). VAS-R/M was significantly decreased at 2, 4, 6, 8, and 12 hours in EDB compared with PPB (P≤0.014), with no significant difference in the mean time to the first request of analgesia and total morphine consumption between the 2 groups. CONCLUSION: Continuous preperitoneal analgesia better attenuated postoperative inflammatory response and provided a comparable overall analgesia to that with continuous epidural analgesia following radical cystectomy.


Assuntos
Analgesia Epidural/métodos , Analgesia/métodos , Inflamação/patologia , Infusões Parenterais , Dor Pós-Operatória/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Adolescente , Adulto , Idoso , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/uso terapêutico , Anestesia Local , Anestésicos Locais/administração & dosagem , Cistectomia/efeitos adversos , Feminino , Humanos , Interleucinas/sangue , Lidocaína/administração & dosagem , Masculino , Pessoa de Meia-Idade , Morfina/administração & dosagem , Morfina/uso terapêutico , Medição da Dor , Complicações Pós-Operatórias/tratamento farmacológico , Estudos Prospectivos , Adulto Jovem
10.
Int J Pharm ; 525(1): 123-138, 2017 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-28392279

RESUMO

The aim of this study was to target a naturally chemotherapeutic agent: ferulic acid to the liver using a biocompatible and an in vivo stable carrier. Accordingly, chitosan as a biopolymer was modified using a hydrophobic moiety and valeric acid in order to increase its in vivo stability. The structure of the newly synthesized product was confirmed using FT-IR and NMR techniques together with the ninhydrin assay. Ferulic acid was conjugated to the modified nanoparticles that were further characterized for particle size, PDI and zeta potential and subjected to ex vivo stability study in serum and cytotoxicity studies in HepG2 cell lines. Furthermore, the nanoparticles were surface-decorated with glycyrrhizin for active liver targeting. The in vivo biodistribution was experimented using radiolabeling assay where the liver scored the highest accumulation of the glycyrrhizin containing nanoparticles after 6h reaching a value of 13.34%ID/g of the total injected dose of labeled drug compared to drug solution and glycyrrhizin free nanoparticles where the accumulation percent did not exceed 4.19%ID/g and 4.26%ID/g, respectively. As a conclusion, the conducted physico-chemical and biological investigations suggested that the proposed selected system can be efficiently utilized as a successful platform for targeting a natural chemotherapeutic agent viz. ferulic acid to the liver.


Assuntos
Quitosana/química , Portadores de Fármacos/química , Ácido Glicirrízico/química , Fígado/efeitos dos fármacos , Nanopartículas/química , Ácidos Cumáricos/administração & dosagem , Células Hep G2 , Humanos , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Distribuição Tecidual , Valeratos
11.
Int J Pharm ; 522(1-2): 128-136, 2017 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-28279742

RESUMO

The active tumor targeting ligands, hyaluronic acid (HA) and human serum albumin (HSA), are considered promising targeting moieties of drug carriers for cancer therapy. The chitosan nanoparticles loaded with methotrexate (MTX-CsNPs) were employed as the core for subsequent coating process. HA and HSA coating solutions were used at different concentrations. The effect of different HA Mw (1000, 360, 10kDa) was also investigated. The coated MTX-CsNPs was characterized proving the success of surface functionalization. The antitumor activity of the prepared MTX-CsNPs was evaluated on MCF-7 breast cancer cell lines. Results showed that both 360 and 10kDa HA allowed for successful HA adsorption, while its Mw and concentration determined negative charge density. HSA coating was accompanied by a slight increase in nanoparticles (NPs) size and a final positive surface charge. The in vitro cytotoxicity proved that HA and HSA coated MTX-CsNPs improved the antitumor activity compared to uncoated NPs and free drug.


Assuntos
Antimetabólitos/administração & dosagem , Antimetabólitos/farmacologia , Quitosana/química , Ácido Hialurônico/química , Metotrexato/administração & dosagem , Metotrexato/farmacologia , Albumina Sérica/química , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Feminino , Humanos , Células MCF-7 , Peso Molecular , Nanopartículas , Tamanho da Partícula
12.
J Biomed Mater Res A ; 105(5): 1433-1445, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28177570

RESUMO

The aim of this work was to study the effect of different physically-adsorbed coating polymers on the cytotoxic activity of optimized bisdemethoxycurcumin (BDMC) loaded-PLGA nanoparticles. BDMC-loaded poly(DL-lactide-co-glycolide) (PLGA) nanoparticles were prepared adopting the nanoprecipitation technique according to a full factorial study design. The effects of three independent variables each at two levels, namely: the polymer type, polymer concentration, and poly vinyl alcohol concentration were studied. The particles were optimized regarding particle size and entrapment efficiency where sizes <200 nm and entrapment efficiencies reaching ∼98% were obtained. The particles were further characterized using x-ray diffraction, transmission electron microscopy, and in-vitro release studies. A selected formulation was subjected to physical coating using various coating moieties, namely: PEG 4000, Tween 80 and Pluronic F68, to impart a hydrophilic stealth character to the surface. The surface hydrophobicity was assessed using the Rose Bengal dye test where the hydrophilicity character followed the following order: Tween 80 > PEG 4000 > Pluronic F68. The particles coating rendered the particles suitable for cancer-targeting regarding particle size measurements, morphology, release kinetics, and stability studies. Moreover, cytotoxicity testing was performed using HepG-2 cells. Coated NPs showed the highest inhibition of malignant cells viability compared to the uncoated NPs and free BDMC where the IC50 of Pluronic-F68 coated NPs was 0.54 ± 0.01 µg/mL. The augmented effect against malignant cells poses these particles as a successful cancer remedy. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1433-1445, 2017.


Assuntos
Materiais Revestidos Biocompatíveis , Curcumina/análogos & derivados , Citotoxinas , Portadores de Fármacos , Nanopartículas , Neoplasias/tratamento farmacológico , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacocinética , Materiais Revestidos Biocompatíveis/farmacologia , Curcumina/química , Curcumina/farmacocinética , Curcumina/farmacologia , Citotoxinas/química , Citotoxinas/farmacocinética , Citotoxinas/farmacologia , Diarileptanoides , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Células Hep G2 , Humanos , Ácido Láctico/química , Ácido Láctico/farmacocinética , Ácido Láctico/farmacologia , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias/metabolismo , Neoplasias/patologia , Ácido Poliglicólico/química , Ácido Poliglicólico/farmacocinética , Ácido Poliglicólico/farmacologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
13.
Drug Deliv ; 24(1): 99-108, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28155540

RESUMO

Usually the topical delivery of ocular drugs poses a great challenge. Accordingly, the work in this study comprised the use of different hybrids of generally regarded as safe (GRAS) oils and surfactants in order to develop and optimize novel acetazolamide (AZD) entrapped-vesicular systems aiming at improving its ocular delivery and reaching better therapeutic outcomes in the treatment of glaucoma. The phospholipid/cholesterol bilayer of the vesicles was enriched with hybrids of Tween 80, Labrasol, Transcutol and Labrafac lipophile WL in different masses and proportions according to a mixture design viz. D-optimal mixture design. Three models were generated comprising three responses: particles size, percentage of entrapment efficiency and amount of drug released after 24 hours (Q24h). The results demonstrated the ability of the penetration enhancing hybrids in modulating the three responses compared to the conventional liposomes. Transmission electron microscope was used to characterize the selected formulations. Sterilization of selected formulations was carried out using gamma radiation and the effect of gamma radiations on entrapment, particle size and in vitro release were studied. The selected sterilized formulations were tested in-vivo on the eyes of albino rabbits in order to evaluate the efficiency of the novel delivery systems on the intra-ocular pressure reduction (IOP) compared to drug solution and the conventional liposomes. The novel formulations proved their efficiency in reducing the IOP to lower values compared to the conventional liposomes, which pose new successful platform for ocular delivery of AZD and other anti-glaucoma drug analogs.


Assuntos
Acetazolamida/administração & dosagem , Colesterol/química , Glaucoma/tratamento farmacológico , Pressão Intraocular/efeitos dos fármacos , Fosfolipídeos/química , Acetazolamida/química , Administração Oftálmica , Composição de Medicamentos , Etilenoglicóis/química , Glaucoma/fisiopatologia , Glicerídeos/química , Lipossomos , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Permeabilidade , Polissorbatos/química , Solubilidade , Tensoativos/química , Tecnologia Farmacêutica/métodos , Triglicerídeos/química
14.
Int J Pharm ; 503(1-2): 127-40, 2016 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-26924357

RESUMO

Lipid-based nanovectors offer effective carriers for brain delivery by improving drug potency and reducing off-target effects. Emulsomes are nano-triglyceride (TG) carriers formed of lipid cores supported by at least one phospholipid (PC) sheath. Due to their surface active properties, PC forms bilayers at the aqueous interface, thereby enabling encapsulated drug to benefit from better bioavailability and stability. Emulsomes of oxcarbazepine (OX) were prepared, aimed to offer nanocarriers for nasal delivery for brain targeting. Different TG cores (Compritol(®), tripalmitin, tristearin and triolein) and soya phosphatidylcholine in different amounts and ratios were used for emulsomal preparation. Particles were modulated to generate nanocarriers with suitable size, charge, encapsulation efficiency and prolonged release. Cytotoxicity and pharmacokinetic studies were also implemented. Nano-spherical OX-emulsomes with maximal encapsulation of 96.75% were generated. Stability studies showed changes within 30.6% and 11.2% in the size and EE% after 3 months. MTT assay proved a decrease in drug toxicity by its encapsulation in emulsomes. Incorporation of OX into emulsomes resulted in stable nanoformulations. Tailoring emulsomes properties by modulating the surface charge and particle size produced a stable system for the lipophilic drug with a prolonged release profile and mean residence time and proved direct nose-to-brain transport in rats.


Assuntos
Anticonvulsivantes/administração & dosagem , Encéfalo/metabolismo , Carbamazepina/análogos & derivados , Portadores de Fármacos/administração & dosagem , Lipídeos/química , Nanopartículas/administração & dosagem , Administração Intranasal , Animais , Anticonvulsivantes/sangue , Anticonvulsivantes/química , Anticonvulsivantes/farmacocinética , Carbamazepina/administração & dosagem , Carbamazepina/sangue , Carbamazepina/química , Carbamazepina/farmacocinética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Liberação Controlada de Fármacos , Humanos , Masculino , Nanopartículas/química , Mucosa Nasal , Oxcarbazepina , Tamanho da Partícula , Ratos Wistar , Propriedades de Superfície
15.
Int J Biol Macromol ; 86: 50-8, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26783636

RESUMO

At a novel pH value of the polymeric solution (6.2), variable chitosan (Cs) and sodium tripolyphosphate (TPP) concentrations and mass ratios were optimized to improve the process yield without undesirable particle flocculation. Prepared formulations were characterized in terms of particle size (PS), zeta potential (ZP) and percentage yield (% yield). Artificial neural networks (ANN) were built up and used to identify the parameters that control nanoparticle (NP) size and yield, in addition to being tested for their ability to predict these two experimental outputs. Using these networks, it was found that TPP concentration has the greatest effect on PS and% yield. The most optimum formulation was characterized by a notable process yield reaching 91.5%, a mean hydrodynamic PS 227 nm, ZP+24.13 mv and spherical compact morphology. Successful Cs-TPP interaction in NP formation was confirmed by both Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). This study demonstrated the ability of ANN to predict not only PS of the formed particles but also NP% yield. This may have a great impact on Cs-TPP NPs preparation and can be used to customize the required target formulations.


Assuntos
Quitosana/química , Portadores de Fármacos/química , Nanopartículas/química , Nanotecnologia/métodos , Redes Neurais de Computação , Polifosfatos/química , Composição de Medicamentos , Concentração de Íons de Hidrogênio
16.
AAPS PharmSciTech ; 9(4): 1230-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19089643

RESUMO

Polysaccharides, which have been explored to possess gelling properties and a wide margin of safety, were used to formulate single-unit floating matrix tablets by a direct compression technique. This work has the aim to allow continuous slow release of famotidine above its site of absorption. The floating approach was achieved by the use of the low density polypropylene foam powder. Polysaccharides (kappa-carrageenan, gellan gum, xyloglucan, and pectin) and blends of polysaccharides (kappa-carrageenan and gellan gum) and cellulose ethers (hydroxypropylmethyl cellulose, hydroxypropylcellulose, sodium carboxymethyl cellulose) were tried to modulate the release characteristics. The prepared floating tablets were evaluated for their floating behavior, matrix integrity, swelling studies, in vitro drug release studies, and kinetic analysis of the release data. The differential scanning calorimetry and Fourier transform infrared spectroscopy studies revealed that changing the polymer matrix system by formulation of polymers blends resulted in formation of molecular interactions which may have implications on drug release characteristics. This was obvious from the retardation in drug release and change in its mechanistics.


Assuntos
Famotidina/farmacocinética , Polissacarídeos/química , Comprimidos , Varredura Diferencial de Calorimetria , Química Farmacêutica , Preparações de Ação Retardada , Famotidina/química , Espectroscopia de Infravermelho com Transformada de Fourier
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA