Targeting αvβ3 and α5β1 for gene delivery to proliferating VSMCs: synergistic effect of TGF-β1

TGF-beta1 levels increase after vascular injury and promote vascular smooth muscle cell (VSMC) proliferation. We define a nonviral gene delivery system that targets alphavbeta3 and alpha5beta1 integrins that are expressed on proliferating VSMCs and strongly induced by TGF-beta1. A 15-amino acid RGDNP-containing peptide from American Pit Viper venom was linked to a Lys(16) peptide as vector (molossin vector) and complexed with Lipofectamine or fusogenic peptide for delivery of luciferase or beta-galactosidase reporter genes to primary cultures of human, rabbit, and rat VSMCs. Preincubation of VSMCs with TGF-beta1 for 24 h, but not with PDGF-BB, interferon-gamma, TNF-alpha, nor PMA, increased alphavbeta3 and alpha5beta1 expressions on VSMCs and enhanced gene delivery of molossin vector. Thus beta-galactosidase activity increased from 35 +/- 5% (controls) to 75 +/- 5% after TGF-beta1 treatment, and luciferase activity increased fourfold over control values. Potential use of this system in vessel bypass surgery was examined in an ex vivo rat aortic organ culture model after endothelial damage. Molossin vector system delivered beta-galactosidase to VSMCs in the vessel wall that remained for up to 12 days posttransfection. The molossin vector system, when combined with TGF-beta1, enhances gene delivery to proliferating VSMCs and might have clinical applications for certain vasculoproliferative diseases.

In vitro characterization of coevaporates containing chitosan for colonic drug delivery

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of chitosan gel as antibiotic and photosensitizer delivery

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tissue distribution of a plasmid DNA encoding Hsp65 gene is dependent on the dose administered through intramuscular delivery

In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system. © 2006 Coelho-Castelo et al; licensee BioMed Central Ltd.

Liposomes and micro/nanoparticles as colloidal carriers for nasal drug delivery

The use of the nasal route for drug delivery has attracted much interest in recent years in the pharmaceutical field. Local and principally systemic drug delivery can be achieved by this route of administration. But the nasal route of delivery is not applicable to all drugs. Polar drugs and some macromolecules are not absorbed in sufficient concentration due to poor membrane permeability, rapid clearance and enzymatic degradation into the nasal cavity. Thus, alternative means that help overcome these nasal barriers are currently in development. Absorption enhancers such as phospholipids and surfactants are constantly used, but care must be taken in relation to their concentration. Drug delivery systems including liposomes, cyclodextrins, micro- and nanoparticles are being investigated to increase the bioavailability of drugs delivered intranasally. This review article discusses recent progress and specific development issues relating to colloidal drug delivery systems in nasal drug delivery. © 2006 Bentham Science Publishers Ltd.

Magnetic multiparticulate colonic delivery systems evaluated by AC Biosusceptometry

The biomagnetic technique called Alternate Current Biosusceptometry (ACB) is a proposal to evaluate a multiparticulate drug delivery system in the human gastrointestinal tract. Results show that ACB was able to quantify the gastrointestinal transit and spreading of the magnetic material and is an attractive tool for pharmaceutical research. © 2007.

Physical factors affecting plasmid DNA compaction in stearylamine-containing nanoemulsions intended for gene delivery

Cationic lipids have been used in the development of non-viral gene delivery systems as lipoplexes. Stearylamine, a cationic lipid that presents a primary amine group when in solution, is able to compact genetic material by electrostatic interactions. In dispersed systems such as nanoemulsions this lipid anchors on the oil/water interface confering a positive charge to them. The aim of this work was to evaluate factors that influence DNA compaction in cationic nanoemulsions containing stearylamine. The influence of the stearylamine incorporation phase (water or oil), time of complexation, and different incubation temperatures were studied. The complexation rate was assessed by electrophoresis migration on agarose gel 0.7%, and nanoemulsion and lipoplex characterization was done by Dynamic Light Scattering (DLS). The results demonstrate that the best DNA compaction process occurs after 120 min of complexation, at low temperature (4 ± 1 °C), and after incorporation of the cationic lipid into the aqueous phase. Although the zeta potential of lipoplexes was lower than the results found for basic nanoemulsions, the granulometry did not change. Moreover, it was demonstrated that lipoplexes are suitable vehicles for gene delivery. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

Nanotechnology-based drug delivery systems for treatment of hyperproliferative skin diseases - a review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Minimum Evaporation Model of Dermatological Delivery Systems. Lamellar Liquid Crystal Formulations Containing Brazilian Nut (Bertholletia excelsa HBK) Vegetable Oil and Guarana Glycolic Extract

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Preparation, characterization and evaluation of drug-delivery systems: Pectin and mefenamic acid films

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nanotechnology-based drug delivery systems for melanoma antitumoral therapy: a review

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Polyacrylic acid polymers hydrogels intended to topical drug delivery: preparation and characterization

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Polymeric Nanoparticles as Oral Delivery Systems for Encapsulation and Release of Polyphenolic Compounds: Impact on Quercetin Antioxidant Activity & Bioaccessibility

A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulation and controlled release of bioactive flavonoids (quercetin). Nanoparticles were fabricated using a solvent displacement method. Particle size, morphology, and charge were measured by light scattering, electron microscopy and zeta-potential. Encapsulation efficiency (EE) and release profiles were determined using electrochemical methods. Molecular interactions within the particle matrix were characterized by X-ray diffraction, differential scanning calorimetry, and infrared spectroscopy. Antioxidant properties of free and encapsulated quercetin were analyzed by TBARS and fluorescence spectroscopy. Bioaccessibility of quercetin was evaluated using an in vitro digestion model. Relatively small (d a parts per thousand aEuro parts per thousand 370 nm) anionic polymeric nanoparticles were formed containing quercetin in a non-crystalline form (EE a parts per thousand aEuro parts per thousand 67 %). The main interaction between quercetin and Eudragit was hydrogen bonding. Encapsulated quercetin remained stable during 6 months storage and maintained its antioxidant activity. Quercetin bioaccessibility within simulated small intestinal conditions was improved by encapsulation. The knowledge obtained from this study will facilitate the rational design and fabrication of polymeric nanoparticles as oral delivery systems for encapsulation, protection, and release of bioactive compounds.

Stratum corneum lipids liposomes for the topical delivery of 5-aminolevulinic acid in photodynamic therapy of skin cancer: preparation and in vitro permeation study

Abstract Background Photodynamic therapy (PDT) using 5-aminolevulinic acid (5-ALA) is a skin cancer therapy that still has limitations due to the low penetration of this drug into the skin. We have proposed in this work a delivery system for 5-ALA based on liposomes having lipid composition similar to the mammalian stratum corneum (SCLLs) in order to optimize its skin delivery in Photodynamic Therapy (PDT) of skin cancers. Methods SCLLs were obtained by reverse phase evaporation technique and size distribution of the vesicles was determinated by photon correlation spectroscopy. In vitro permeation profile was characterized using hairless mouse skin mounted in modified Franz diffusion cell. Results Size exclusion chromatography on gel filtration confirmed vesicle formation. SCLLs obtained by presented a degree of encapsulation of 5-ALA around 5.7%. A distribution of vesicle size centering at around 500 nm and 400 nm respectively for SCLLs and SCLLs containing 5-ALA was found. In vitro 5-ALA permeation study showed that SCLLs preparations presented higher skin retention significantly (p < 0.05) on the epidermis without SC + dermis, with a decreasing of skin permeation compared to aqueous solution. Conclusions The in vitro delivery performance provided by SCLLs lead to consider this systems adequate for the 5-ALA-PDT of skin cancer, since SCLLs have delivered 5-ALA to the target skin layers (viable epidermis + dermis) to be treated by topical PDT of skin cancer.

Tissue distribution of a plasmid DNA encoding Hsp65 gene is dependent on the dose administered through intramuscular delivery

In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system.