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1.
Int J Pharm ; 630: 122463, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36462738

RESUMO

COVID-19 is caused by the infection of the lungs by SARS-CoV-2. Monoclonal antibodies, such as sotrovimab, showed great efficiency in neutralizing the virus before its internalization by lung epithelial cells. However, parenteral routes are still the preferred route of administration, even for local infections, which requires injection of high doses of antibody to reach efficacious concentrations in the lungs. Lung administration of antibodies would be more relevant requiring lower doses, thus reducing the costs and the side effects. But aerosolization of therapeutic proteins is very challenging, as the different processes available are harsh and trigger protein aggregation and conformational changes. This decreases the efficiency of the treatment, and can increase its immunogenicity. To address those issues, we developed a series of new excipients composed of a trehalose core, a succinyl side chain and a hydrophobic carbon chain (from 8 to 16 carbons). Succinylation increased the solubility of the excipients, allowing their use at relevant concentrations for protein stabilization. In particular, the excipient with 16 carbons (C16TreSuc) used at 5.6 mM was able to preserve colloidal stability and antigen-binding ability of sotrovimab during the nebulization process. It could also be used as a cryoprotectant, allowing storage of sotrovimab in a lyophilized form during weeks. Finally, we demonstrated that C16TreSuc could be used as an excipient to stabilize antibodies for the treatment against COVID-19, by in vitro and in vivo assays. The presence of C16TreSuc during nebulization preserved the neutralization capacity of sotrovimab against SARS-CoV-2 in vitro; an increase of its efficacy was even observed, compared to the non-nebulized control. The in vivo study also showed the wide distribution of sotrovimab in mice lungs, after nebulization with 5.6 mM of excipient. This work brings a solution to stabilize therapeutic proteins during storage and nebulization, making pulmonary immunotherapy possible in the treatment of COVID-19 and other lung diseases.


Assuntos
COVID-19 , Excipientes , Camundongos , Animais , Excipientes/química , Trealose/química , SARS-CoV-2 , Anticorpos Antivirais
2.
Adv Drug Deliv Rev ; 176: 113837, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34144089

RESUMO

Compared to chemicals that continue to dominate the overall pharmaceutical market, protein therapeutics offer the advantages of higher specificity, greater activity, and reduced toxicity. While nearly all existing therapeutic proteins were developed against soluble or extracellular targets, the ability for proteins to enter cells and target intracellular compartments can significantly broaden their utility for a myriad of exiting targets. Given their physical, chemical, biological instability that could induce adverse effects, and their limited ability to cross cell membranes, delivery systems are required to fully reveal their biological potential. In this context, as natural protein nanocarriers, extracellular vesicles (EVs) hold great promise. Nevertheless, if not present naturally, bringing an interest protein into EV is not an easy task. In this review, we will explore methods used to load extrinsic protein into EVs and compare these natural vectors to their close synthetic counterparts, liposomes/lipid nanoparticles, to induce intracellular protein delivery.


Assuntos
Vesículas Extracelulares/metabolismo , Lipossomos , Nanopartículas , Proteínas/administração & dosagem , Animais , Sistemas de Liberação de Medicamentos , Humanos , Proteínas/efeitos adversos , Proteínas/metabolismo
3.
RSC Adv ; 11(49): 30887-30897, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-35498928

RESUMO

Hybrid hydrogels based on silylated polyethylene glycol, Si-PEG, were evaluated as hybrid matrices able to trap, stabilize and release bovine serum albumin (BSA) in a controlled manner. Parameters of the inorganic condensation reaction leading to a siloxane (Si-O-Si) three dimensional network were carefully investigated, in particular the temperature, the surrounding hygrometry and the Si-PEG concentration. The resulting hydrogel structural features affected the stability, swelling, and mechanical properties of the network, leading to different protein release profiles. Elongated polymer assemblies were observed, the length of which ranged from 150 nm to over 5 µm. The length could be correlated to the Si-O-Si condensation rate from 60% (hydrogels obtained at 24 °C) to about 90% (xerogels obtained at 24 °C), respectively. Consequently, the controlled release of BSA could be achieved from hours to several weeks, with respect to the fibers' length and the condensation rate. The protein stability was evaluated by means of a thermal study. The main results gave insight into the biomolecule structure preservation during polymerisation, with ΔG < 0 for encapsulated BSA in any conditions, below the melting temperature (65 °C).

4.
J Pharm Sci ; 110(3): 1197-1205, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33069708

RESUMO

The aim of this work was to carry out a preformulation study on JMV5038 as a new potent cytotoxic agent, and to develop its formulation within vegetable oil-based hybrid submicron particles (HNP) in order to obtain a versatile dosage form against melanoma. JMV5038 was first characterized through physico-chemical tests and it exhibited high melting point and logP value, an important pH-sensitivity that led to the formation of well-identified degradation products at low pH, as well as a substantial solubility value in silylated castor oil (ICO). Then, JMV5038-loaded HNP were formulated through a thermostabilized emulsion process based on the sol-gel cross-linking of ICO. They showed high loading efficiency and their in vitro release kinetic assessed in a biorelevant PBS/octanol biphasic system showed a constant sustained release over one month. The cytotoxic activity and cytocompatibility of HNP were evaluated on A375 melanoma cells and NIH 3T3 cells, respectively. JMV5038-loaded HNP exhibited a slightly enhanced cytotoxic activity of JMV5038 on melanoma cells while demonstrating their safety on NIH 3T3 cells. In conclusion, JMV5038-loaded HNP proved to be an efficient and safe drug subcutaneous delivery system that will be interesting to evaluate through preclinical studies.


Assuntos
Melanoma , Óleos de Plantas , Animais , Óleo de Rícino , Emulsões , Melanoma/tratamento farmacológico , Camundongos , Tamanho da Partícula , Solubilidade
5.
Int J Pharm ; 592: 120070, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33188895

RESUMO

The aim of this study was to evidence the ability of vegetable oil-based hybrid microparticles (HMP) to be an efficient and safe drug delivery system after subcutaneous administration. The HMP resulted from combination of a thermostabilized emulsification process and a sol-gel chemistry. First of all, castor oil was successfully silylated by means of (3-Isocyanatopropyl)trimethoxysilane in solvent-free and catalyst-free conditions. Estradiol, as a model drug, was dissolved in silylated castor oil (ICOm) prior to emulsification, and then an optimal sol-gel crosslinking was achieved inside the ICOm microdroplets. The resulting estradiol-loaded microparticles were around 80 µm in size and allowed to entrap 4 wt% estradiol. Their release kinetics in a PBS/octanol biphasic system exhibited a one-week release profile, and the released estradiol was fully active on HeLa ERE-luciferase ERα cells. The hybrid microparticles were cytocompatible during preliminary tests on NIH 3T3 fibroblasts (ISO 10993-5 standard) and they were fully biocompatible after subcutaneous injection on mice (ISO 10993-6 standard) underlining their high potential as a safe and long-acting subcutaneous drug delivery system.


Assuntos
Preparações Farmacêuticas , Óleos de Plantas , Animais , Óleo de Rícino , Sistemas de Liberação de Medicamentos , Camundongos , Tamanho da Partícula , Solventes
6.
Materials (Basel) ; 13(16)2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32806728

RESUMO

A novel bio-hybrid drug delivery system was obtained involving a Mg/Al-NO3 layered double hydroxide (LDH) intercalated either with ibuprofenate anions (IBU) or a phospholipid bilayer (BL) containing a neutral drug, i.e., 17ß-estradiol, and then embedded in chitosan beads. The combination of these components in a hierarchical structure led to synergistic effects investigated through characterization of the intermediates and the final bio-composites by XRD, TG, SEM, and TEM. That allowed determining the presence and yield of IBU and of BL in the interlayer space of LDH, and of the encapsulated LDH in the beads, as well as the morphology of the latter. Peculiar attention has been paid to the intercalation process of the BL for which all available data substantiate the hypothesis of a first interaction at the defect of the LDH, as well as on the interaction mode of these components. 1H, 31P and 27Al MAS-NMR studies allowed establishing that the intercalated BL is not homogeneous and likely formed patches. Release kinetics were performed for sodium ibuprofenate as well as for the association of 17ß-estradiol within the negatively charged BL, each encapsulated in the LDH/chitosan hybrid materials. Such new bio-hybrids offer an interesting outlook into the pharmaceutical domain with the ability to be used as sustained release systems for a wide variety of anionic and, importantly, neutral drugs.

7.
Langmuir ; 35(39): 12597-12612, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31461287

RESUMO

Microfluidics is one of the most fascinating fields that researchers have been trying to apply in a large number of scientific disciplines over the past two decades. Among them, the discipline of food and pharmaceutical formulation encountered several obstacles when combining microfluidics with aqueous media. Indeed, the physical properties of liquids at micrometric volumes being particular, the droplet generation within microfluidic devices is a big challenge to be met. This focus review is intended to be an initiation for those who would like to generate microdroplets in microfluidic systems involving aqueous continuous phases. It provides a state-of-the-art look at such systems while focusing on the microfluidic devices used, their applications to form a wide variety of emulsions and particles, and the key role held by the interface between the device channels and the emulsion. This review also leads to reflections on new materials that can be used in microfluidic systems with aqueous continuous phases.

8.
Int J Pharm ; 567: 118478, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260782

RESUMO

To encapsulate and deliver poorly water-soluble drugs, castor oil/silica hybrid microparticles (HMP)s were synthesized. Green chemistries were used to silylate the oil and further cross-link it into solid microparticles by sol-gel reaction. Silylated castor oils (ICO)s at various silylation ratios were prepared and allowed the solubilization of ibuprofen at several concentrations up to 16 wt%. The HMPs were formulated by ThermoStabilized Emulsion (TSE) process which permits to "freeze" the oil-in-water emulsion while the sol-gel reaction occurs. The hybrid mineral/organic composition and the morphology (spherical shape and micrometric size) of these HMPs were determined by complementary technics (SEM, TGA, EDX, 29Si NMR and FTIR spectroscopies). The HMPs reached a good ibuprofen loading efficiency regardless to the formulation used while the release kinetics in simulated oral administration exhibited a tunable release during 3 h according to the silylation ratio. The ibuprofen rate also influenced its own amorphous or crystalline character within the HMPs. For subcutaneous conditions, ibuprofen release took place over 15 days. Finally, biodegradability assays in simulated digestion medium suggested a surface-limited hydrolysis of the particles and cytocompatibility studies on NIH-3T3 and Caco-2 cells demonstrated an excellent cellular viability.


Assuntos
Óleo de Rícino/administração & dosagem , Portadores de Fármacos/administração & dosagem , Dióxido de Silício/administração & dosagem , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Células CACO-2 , Óleo de Rícino/química , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Humanos , Ibuprofeno/administração & dosagem , Ibuprofeno/química , Camundongos , Células NIH 3T3 , Dióxido de Silício/química , Solubilidade , Água/química
9.
Langmuir ; 35(20): 6620-6629, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31042395

RESUMO

Nanofilms of about 2 nm thickness have been formed at the air-water interface using functionalized castor oil (ICO) with cross-linkable silylated groups. These hybrid films represent excellent candidates for replacing conventional polymeric materials in biomedical applications, but they need to be optimized in terms of biocompatibility, which is highly related to protein adsorption. Neutron reflectivity has been used to study the adsorption of two model proteins, bovine serum albumin and lysozyme, at the silylated oil (ICO)-water interface in the absence and presence of salt at physiologic ionic strength and pH and at different protein concentrations. These measurements are compared to adsorption at the air-water interface. While salt enhances adsorption by a similar degree at the air-water and oil-water interfaces, the impact of the oil film is significant with adsorption at the oil-water interface 3-4-fold higher compared to that at the air-water interface. Under these conditions, the concentration profiles of the adsorbed layers for both proteins indicate multilayer adsorption. The thickness of the outer layer (oil side) is close to the dimension of the minor axis of the protein molecule, ∼30 Å, suggesting a sideway orientation with the long axis parallel to the interface. The inner layer extends to 55-60 Å. Interestingly, in all cases, the composition of the oil film remains intact without significant protein penetration into the film. The optimal adsorption on these nanofilms, 1.7-2.0 mg·m-2, is comparable to the results obtained recently on thick solid cross-linked films using a quartz crystal microbalance and atomic force microscopy, showing in particular that adsorption at these ICO film interfaces under standard physiological conditions is nonspecific. These results furnish useful information toward the elaboration of vegetable oil-based nanofilms in direct nanoscale applications or as precursor films in the fabrication of thicker macroscopic films for biomedical applications.


Assuntos
Membranas Artificiais , Modelos Químicos , Muramidase/química , Difração de Nêutrons , Óleos de Plantas/química , Soroalbumina Bovina/química , Adsorção
10.
Soft Matter ; 13(26): 4569-4579, 2017 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-28613327

RESUMO

Vegetable oil based hybrid films were developed thanks to a novel solvent- and heating-free method at the air-water interface using silylated castor oil cross-linked via a sol-gel reaction. To understand the mechanism of the hybrid film formation, the reaction kinetics was studied in detail by using complementary techniques: rheology, thermogravimetric analysis, and infrared spectroscopy. The mechanical properties of the final films were investigated using nano-indentation, whereas their structure was studied using a combination of wide-angle X-ray scattering, electron diffraction, and atomic force microscopy. We found that solid and transparent films form in 24 hours and, by changing the silica precursor to castor oil ratio, their mechanical properties are tunable in the MPa-range by about a factor of twenty. In addition to that, a possible optimization of the cross-linking reaction with different catalysts was explored, and finally cytotoxicity tests were performed on fibroblasts proving the absence of film toxicity. The results of this work pave the way to a straightforward synthesis of castor-oil films with tunable mechanical properties: hybrid films cross-linked at the air-water interface combine an easy and cheap spreading protocol with the features of their thermal history optimized for possible future micro/nano drug loading, thus representing excellent candidates for the replacement of non-environmentally friendly petroleum-based materials.

11.
Int J Pharm Investig ; 7(4): 155-163, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29692974

RESUMO

OBJECTIVE: EAPB0503, lead compound of imiqualines, presented high antitumor activities but also a very low water solubility which was critical for further preclinical studies. To apply to EAPB0503, a robust and safe lipid formulation already used for poor soluble anticancer agents for injectable administration at a concentration higher than 1 mg/mL. MATERIALS AND METHODS: Physicochemical properties of EAPB0503 were determined to consider an adapted formulation. In a second time, lipid nanocapsules (LNC) formulations based on the phase-inversion process were developed for EAPB0503 encapsulation. Then, EAPB0503 loaded-LNC were tested in vitro on different cell lines and compared to standard EAPB0503 solutions. RESULTS: Optimized EAPB0503 LNC displayed an average size of 111.7 ± 0.9 nm and a low polydispersity index of 0.059 ± 0.002. The obtained loading efficiency was higher than 96% with a drug loading of 1.7 mg/mL. A stability study showed stability during 4 weeks stored at 25°C. In vitro results highlighted similar efficiencies between LNC and standard EAPB0503 solutions prepared in dimethyl sulfoxide. CONCLUSION: In view of results obtained for loading efficiency and drug loading, the use of a LNC formulation is very interesting to permit the solubilization of a lipophilic drug and to improve its bioavailability. Preliminary tested pharmaceutical formulation applied to EAPB0503 significantly improved its water solubility and will be soon considered for future preclinical in vivo studies.

12.
Eur J Pharm Biopharm ; 92: 216-27, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25796349

RESUMO

Dendritic cells (DCs) are professional antigen-presenting cells that play a critical role in maintaining the balance between immunity and tolerance and, as such are a promising immunotherapy tool to induce immunity or to restore tolerance. The main challenge to harness the tolerogenic properties of DCs is to preserve their immature phenotype. We recently developed polyion complex micelles, formulated with double hydrophilic block copolymers of poly(methacrylic acid) and poly(ethylene oxide) blocks and able to entrap therapeutic molecules, which did not induce DC maturation. In the current study, the intrinsic destabilizing membrane properties of the polymers were used to optimize endosomal escape property of the micelles in order to propose various strategies to restore tolerance. On the first hand, we showed that high molecular weight (Mw) copolymer-based micelles were efficient to favor the release of the micelle-entrapped peptide into the endosomes, and thus to improve peptide presentation by immature (i) DCs. On the second hand, we put in evidence that low Mw copolymer-based micelles were able to favor the cytosolic release of micelle-entrapped small interfering RNAs, dampening the DCs immunogenicity. Therefore, we demonstrate the versatile use of polyionic complex micelles to preserve tolerogenic properties of DCs. Altogether, our results underscored the potential of such micelle-loaded iDCs as a therapeutic tool to restore tolerance in autoimmune diseases.


Assuntos
Células Dendríticas/imunologia , Peptídeos/administração & dosagem , Polímeros/química , RNA Interferente Pequeno/administração & dosagem , Endossomos/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Tolerância Imunológica , Micelas , Peso Molecular , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química
13.
Int J Pharm ; 454(2): 611-20, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23792466

RESUMO

Poly(methacrylic acid)-b-poly(ethylene oxide) are double hydrophilic block copolymers, which are able to form micelles by complexation with a counter-polycation, such as poly-l-lysine. A study was carried out on the ability of the copolymers to interact with model membranes as a function of their molecular weights and as a function of pH. Different behaviors were observed: high molecular weight copolymers respect the membrane integrity, whereas low molecular weight copolymers with a well-chosen asymmetry degree can induce a membrane alteration. Hence by choosing the appropriate molecular weight, micelles with distinct membrane interaction behaviors can be obtained leading to different intracellular traffics with or without endosomal escape, making them interesting tools for cell engineering. Especially micelles constituted of low molecular weight copolymers could exhibit the endosomal escape property, which opens vast therapeutic applications. Moreover micelles possess a homogeneous nanometric size and show variable properties of disassembly at acidic pH, of stability in physiological conditions, and finally of cyto-tolerance.


Assuntos
Sistemas de Liberação de Medicamentos , Micelas , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Animais , Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Células HEK293 , Hemoglobinas/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Lipossomos , Membranas Artificiais , Camundongos , Camundongos Endogâmicos C57BL , Peso Molecular , Polietilenoglicóis/farmacologia , Ácidos Polimetacrílicos/farmacologia
14.
J Control Release ; 154(2): 156-63, 2011 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-21624406

RESUMO

For many years, a great deal of interest has been focusing on the optimization of peptide presentation by dendritic cells (DCs) using peptide-encapsulated particles, in order to enhance the immune response. Nowadays, DCs are also known to be involved in peripheral tolerance, inducing anergy or regulatory T lymphocytes. To preserve the plasticity of DCs, we formulated non-cytotoxic pH-sensitive polyion complex micelles based on an original tripartite association of polymethacrylic acid-b-polyethylene oxide, poly-L-lysine and fluorescent-peptide: OVAFITC peptide, as a model drug. We demonstrated that the OVAFITC peptide was successfully entrapped into the micelles, released into DC endosomes thanks to the pH-sensitivity property of the micelles, and efficiently loaded onto MHC class II molecules. The phenotype as well as the cytokinic secretion profile of the mature and immature DCs loaded with peptide-encapsulated micelles was unaltered by the tripartite polyion micelles. The efficient loading of the peptide by immature and mature DCs was shown by the in vitro proliferation of OVA-specific transgenic T cells. Therefore, the present results show that the tripartite polyion complex micelles can be used as efficient peptide vectors immunogically inert for ex vivo DCs engineering without modifying their intrinsic immune plasticity.


Assuntos
Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Sistemas de Liberação de Medicamentos/métodos , Micelas , Fragmentos de Peptídeos/administração & dosagem , Sequência de Aminoácidos , Animais , Células Cultivadas , Células Dendríticas/transplante , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Ovalbumina/administração & dosagem , Ovalbumina/genética , Ovalbumina/metabolismo , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/metabolismo , Ácidos Polimetacrílicos/administração & dosagem , Ácidos Polimetacrílicos/metabolismo
15.
Int J Pharm ; 379(2): 212-7, 2009 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-19467303

RESUMO

In the recent years, double-hydrophilic block copolymer (DHBC) micelles have appeared as potential vectors for pharmaceutical applications due to their simple preparation method in aqueous solvent. The present study aims at underscoring the strategy for the choice of the partners in the formulation of DHBC micelles presenting a good stability in physiological conditions (pH 7.4, 0.15 mol/L NaCl) and a pH-sensitivity allowing their disassembly at pH 5. Using light scattering and Laser-Doppler electrophoresis, micelles of polymethacrylic acid-b-polyethylene oxide complexing either poly-l-lysine (PLL) or an oligochitosan were characterised. Whatever the polyamine counter-polyion considered, the micelles were perfectly formed for an amine/methacrylic acid molar charge ratio of one. They were characterised by a hydrodynamic diameter of 28 nm for PLL and 60 nm for oligochitosan and by a neutral zeta potential. The stability study as a function of the pH and of the ionic strength revealed different behaviours. Oligochitosan micelles were stable until pH 7 and unstable at 0.15 mol/L NaCl. On the contrary, PLL micelles were stable in physiological conditions and disassembled at pH 5. As a conclusion, the choice of the partners to formulate double-hydrophilic block copolymer based-micelles is strategic in order to obtain well-adapted vectors applied to the pharmaceutical field.


Assuntos
Química Farmacêutica/métodos , Micelas , Polietilenoglicóis/síntese química , Polímeros/síntese química , Ácidos Polimetacrílicos/síntese química , Concentração de Íons de Hidrogênio , Polilisina/síntese química
16.
Drug Dev Ind Pharm ; 35(8): 950-8, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19274590

RESUMO

Dendritic cells (DCs) are key cells in immunology that are able to stimulate or inhibit the immune response. RNA interference has appeared of great interest to modulate the expression of immunogenic or tolerogenic molecules. In our study, pH-sensitive polyion complex micelles based on a double-hydrophilic block copolymer and poly-L-lysine were formulated to entrap a small interfering RNA (siRNA). We show that siRNA-loaded micelles were cytotolerant and efficiently endocytosed by DCs. siRNA targeting eGFP, used as model siRNA, was released into the cytosol following endocytosis of the micelles and the silencing of eGFP expression was observed in DC isolated from transgenic mice. Our results underscore the potential of pH-sensitive polyion complex micelles to formulate therapeutic siRNA for DC engineering in order to maintain the homeostasis of the immune response.


Assuntos
Células Dendríticas/metabolismo , Inativação Gênica , RNA Interferente Pequeno/administração & dosagem , Animais , Citosol/metabolismo , Endocitose , Proteínas de Fluorescência Verde/genética , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Micelas , Polilisina/química
17.
Biomaterials ; 30(2): 233-41, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18851879

RESUMO

Double-hydrophilic block copolymer micelles were designed as vectors for ex vivo dendritic cell engineering to improve the delivery of therapeutic molecules in such immune cells. Polymethacrylic acid-b-polyethylene oxide (PMAA(2100)-b-POE(5000))/poly-L-lysine micelles were optimised and showed a hydrodynamic diameter of 30 nm with a peculiar core organised with hydrogen bonds as well as hydrophobic domains. The micelles proved high stability in physiological conditions (pH and ionic strength) and were also able to disassemble under acidic conditions mimicking acidic endolysosomes. The efficient endocytosis of the optimised micelles tested on bone marrow-derived dendritic cells was monitored by fluorescence-activated cell sorting and microscopy analysis. Finally, the micelle biocompatibility permitted a complete control of the dendritic cell-maturation process widening the therapeutical potential of such engineered dendritic cells for cancer vaccines as well as for immunomodulation in autoimmune diseases.


Assuntos
Células Dendríticas/citologia , Micelas , Polietilenoglicóis/química , Polilisina/química , Ácidos Polimetacrílicos/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Endocitose/efeitos dos fármacos , Citometria de Fluxo , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Polímeros/química , Polímeros/farmacologia
18.
Biomaterials ; 28(11): 1978-88, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17240442

RESUMO

To improve the outcome of foetal dopaminergic cell transplantation for the treatment of Parkinson's disease, pharmacologically active microcarriers (PAM) were developed. PAM are able to convey cells on their surface and release a growth factor to improve cell survival, differentiation and integration after brain implantation. Lysozyme-releasing PAM were first produced and characterized. They served as a model system for the development of glial cell line-derived neurotrophic factor (GDNF)-releasing PAM conveying foetal ventral mesencephalic (FVM) cells. The effects of the intrastriatal implantation of this system were studied in hemiparkinsonian rats during a 6-week period. This study reports on the degradation of coated and non-coated PAM and the release of lysozyme and of biologically active GDNF for 42 days. Unloaded and GDNF-loaded PAM conveying FVM cells allowed a high improvement of the grafted cell survival and of fibre outgrowth, when compared to the cells transplanted alone. The animals receiving the PAM showed an earlier improvement in amphetamine-induced rotational behaviour compared to animals receiving FVM cells only; behaviour that appears to be more regular and stable with the GDNF-releasing PAM. The use of PAM to convey foetal cells is thus an efficient strategy for cell therapy in neurodegenerative diseases, as it allows improvement of cell survival and fibre outgrowth inducing a rapid recovery of behaviour using only low amounts of cells.


Assuntos
Materiais Biocompatíveis/química , Encéfalo/embriologia , Dopamina/metabolismo , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Engenharia Tecidual/métodos , Animais , Diferenciação Celular , Sobrevivência Celular , Feminino , Microesferas , Neurônios/metabolismo , Doença de Parkinson/metabolismo , Doença de Parkinson/terapia , Ratos , Ratos Sprague-Dawley , Células-Tronco/citologia
19.
J Control Release ; 118(1): 1-6, 2007 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-17250924

RESUMO

Preliminary tests in the field of drug storage and release of composite materials known as liposils were described. These silica-based particles were obtained via liposome templating. The non-porous amorphous silica cladding of liposils protected the liposomes which retained the fundamental properties of their phospholipid bilayer. In an improved synthesis, two formulations were used, one with and the other without cholesterol in the phospholipid bilayer. Stability tests were done using carboxyfluorescein as a model hydrophilic drug loaded in the liposomes aqueous phase before the templating process. The stability of the loaded liposils was analyzed at two different pH (1.2 and 7.4) in a flow cell, according to the USP 28 norm. At pH 1.2, the silica shell was stable and prevented their rapid degradation. Interestingly, at pH 7.4 the analysis of the release kinetics revealed that the hydrolysis of the silica shell initially released intact liposomes. Characterizations of liposils were done at various steps of these processes. The stability observed for liposils make them good starting material for drug storage and release schemes. For instance, functionalization of their external surface should improve their capture by cells whereby drug release could then be induced by external stimuli, such as ultrasounds or microwaves.


Assuntos
Química Farmacêutica/métodos , Preparações de Ação Retardada/farmacocinética , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Dióxido de Silício , Colesterol/química , Portadores de Fármacos/síntese química , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Fluoresceínas/química , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Bicamadas Lipídicas/química , Lipossomos/síntese química , Lipossomos/química , Fosfolipídeos/química , Dióxido de Silício/administração & dosagem , Dióxido de Silício/síntese química , Dióxido de Silício/química , Água/química
20.
Mol Cancer Ther ; 5(7): 1710-22, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16891457

RESUMO

By focusing on rat glioma, we elucidated whether new lipid nanocapsules (LNC) were able to improve anticancer hydrophobic drug bioavailability while also overcoming multidrug resistance. Blank LNCs and LNCs loaded with the antineoplastic agent paclitaxel were formulated by an emulsion inversion phase process. Expression of efflux pumps by rat glioma cells was assessed by reverse transcription-PCR, Western blot, and immunohistochemistry, and their activity was followed using the tracer (99)Tc(m)-methoxyisobutylisonitrile. Modalities of LNC action were addressed by using confocal microscopy detection of fluorescently labeled LNCs, fluorescence-activated cell sorting, high-performance liquid chromatography measurement of paclitaxel release, and analysis of tumor cell growth. This revealed an interaction between LNCs and efflux pumps that resulted in an inhibition of multidrug resistance in glioma cells, both in culture and in cell implants in animals. LNCs were able to target the intracellular compartment of glioma cells, a mechanism that was abrogated by using intracellular cholesterol inhibitors but not by clathrin-coated pit or caveolae uptake inhibitors. This result can be correlated to the LNC inhibitory effects on efflux pump activity that is itself known to be stimulated by intracellular cholesterol. In parallel, we showed that paclitaxel-loaded LNCs were active reservoirs from which paclitaxel could be released. Finally, we established that paclitaxel-loaded LNCs were more efficient than the commercially available paclitaxel formulation (Taxol) for clinical use, thus reducing tumor expansion in vitro and in vivo. Considering the physiologically compatible nature of LNC excipients, these data may represent an important step towards the development of new clinical therapeutic strategies against cancers.


Assuntos
Antineoplásicos/administração & dosagem , Portadores de Fármacos/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glioma/tratamento farmacológico , Nanoestruturas/química , Subfamília B de Transportador de Cassetes de Ligação de ATP/análise , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/análise , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Cápsulas/administração & dosagem , Cápsulas/metabolismo , Portadores de Fármacos/metabolismo , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Endocitose , Glioma/metabolismo , Masculino , Nitrilas/análise , Paclitaxel/administração & dosagem , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos F344 , Membro 4 da Subfamília B de Transportadores de Cassetes de Ligação de ATP
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