RESUMO
This work describes a novel delivery system for targeting egg-derived anti-inflammatory tripeptide Ile-Arg-Trp (IRW) to endothelial cells. The nanomedicine is synthesized by a simple and reproducible ionotropic gelification method that results in the efficient loading of the positively charged IRW within the dermatan sulfate/ chitosan matrix, as demonstrated by ss-NMR spectroscopy. The incorporation of IRW results in a stable nanoparticle dispersion with a single size population of 442⯱â¯43â¯nm. Fluorescence microscopy studies demonstrate the capacity of the nanomaterial to distinguish between a quiescent and an injured endothelium through the interaction of dermatan sulfate with the CD44 receptor. Remarkably, no additional surface functionalization is required as dermatan sulfate mediates their internalization and the intracellular release of this natural anti-inflammatory tripeptide to modulate endothelial inflammatory response. This simple, scalable, and versatile nanotechnology platform opens new opportunities to apply in the therapy of vascular disease.
Assuntos
Anti-Inflamatórios/administração & dosagem , Quitosana/análogos & derivados , Dermatan Sulfato/química , Nanopartículas/química , Oligopeptídeos/administração & dosagem , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Células Cultivadas , Liberação Controlada de Fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Receptores de Hialuronatos/metabolismo , Camundongos , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Ligação ProteicaRESUMO
Interferon alpha (IFNα) is a protein drug used to treat viral infections and cancer diseases. Due to its poor stability in the gastrointestinal tract, only parenteral administration ensures bioavailability, which is associated with severe side effects. We hypothesized that the nanoencapsulation of IFNα within nanoparticles of the mucoadhesive polysaccharide chitosan would improve the oral bioavailability of this drug. In this work, we produced IFNα-loaded chitosan nanoparticles by the ionotropic gelation method. Their hydrodynamic diameter, polydispersity index and concentration were characterized by dynamic light scattering and nanoparticle tracking analysis. After confirming their good cell compatibility in Caco-2 and WISH cells, the permeability of unmodified and poly(ethylene glycol) (PEG)-modified (PEGylated) nanoparticles was measured in monoculture (Caco-2) and co-culture (Caco-2/HT29-MTX) cell monolayers. Results indicated that the nanoparticles cross the intestinal epithelium mainly by the paracellular route. Finally, the study of the oral pharmacokinetics of nanoencapsulated IFNα in BalbC mice revealed two maxima and area-under-the-curve of 56.9 pg*h/mL.
RESUMO
Despite the wide range of diseases affecting the eye, ocular bioavailability remains a challenge in ophthalmic drug delivery. Nowadays an extensive variety of polymers are being explored to develop colloidal drug carriers which show better performance than the more popular drug solutions. For instance, regardless of the type of polymer used, these systems prolong the residence time of the drug in the absorption site with respect to conventional aqueous eye drops which are rapidly cleared from eye surface. Furthermore, colloidal drug carriers can be internalized by cells. In addition, positively charged particles penetrate the cornea more effectively than neutral or negatively charged ones. These phenomena lead to higher ocular bioavailability. This review overviews the different polymers available to produce drug-loaded gels, microparticles and nanoparticles, highlighting the advantageous features and biocompatibility of each polymer and the major achievements in the field of ocular delivery. In addition, the design of more complex delivery systems that combine several delivery platforms is presented. Finally, regulatory aspects relevant to the clinical translation of advanced ophthalmic drug delivery systems are also discussed. All together, this manuscript is aimed at guiding pharmaceutical research and development towards the rationale polymer selection to produce drug delivery systems that improve the performance of drugs for the therapy of ophthalmic diseases.
Assuntos
Portadores de Fármacos/química , Oftalmopatias/tratamento farmacológico , Preparações Farmacêuticas/administração & dosagem , Polímeros/química , Administração Oftálmica , Animais , Disponibilidade Biológica , Sistemas de Liberação de Medicamentos/métodos , Olho/efeitos dos fármacos , Olho/metabolismo , Oftalmopatias/metabolismo , Humanos , FarmacocinéticaRESUMO
Cardiovascular disease is the largest single cause of morbid-mortality in the world. However, there is still no pharmaceutical treatment that directly targets the blood vessel wall instead of just controlling the risk factors. Here, we produced polyelectrolyte complexes (PECs) by a simple and reproducible polyelectrolyte complexation method between low molecular mass dermatan sulfate (polyanionic polysaccharide) and chitosan (polycationic polysaccharide), and evaluated the cellular uptake by vascular endothelial cells. The composition and the composition homogeneity of PECs were confirmed by (13)C-CP-MAS spectroscopy and by polyacrylamide gel electrophoresis, respectively. The hydrodynamic radius, determined by dynamic light scattering, was 729±11nm. PECs were not cytotoxic for a murine heart endothelium-derived cell line. Fluorescent confocal microscopy showed the specific uptake of fluorescently-labeled PECs by endothelial cells when they were cultured alone or in the presence of macrophages. Overall, these findings confirmed the potential of these PECs for targeting different agents to the vessel wall in the prevention, diagnosis, and therapy of vascular disease.
Assuntos
Quitosana/química , Dermatan Sulfato/química , Polieletrólitos/química , Doenças Vasculares/diagnóstico , Doenças Vasculares/tratamento farmacológico , Animais , Transporte Biológico , Células Endoteliais/metabolismo , Camundongos , Peso Molecular , Polieletrólitos/metabolismo , Polieletrólitos/uso terapêutico , Células RAW 264.7 , Doenças Vasculares/prevenção & controleRESUMO
AIM: To assess the involvement of ABCG2 in the pharmacokinetics of efavirenz in the blood-brain barrier (BBB) and investigate a nanotechnology strategy to overcome its overexpression under a model of chronic oral administration. Materials & methods A model of chronic efavirenz (EFV) administration was established in male Sprague-Dawley rats treated with a daily oral dose over 5 days. Then, different treatments were conducted and drug concentrations in plasma and brain measured. RESULTS: Chronic treatment with oral EFV led to the overexpression of ABCG2 in the BBB that was reverted after a brief washout period. Moreover, gefitinib and the polymeric amphiphile Tetronic(®) 904 significantly inhibited the activity of the pump and potentiated the accumulation of EFV in CNS. The same effect was observed when the drug was administered within mixed micelles containing TetronicT904 as the main component. CONCLUSION: Tetronic 904-containing polymeric micelles overcame the overexpression of ABCG2 in the BBB caused by chronic administration of EFV then boosting its penetration into the CNS.
Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Benzoxazinas/farmacocinética , Barreira Hematoencefálica , Etilenodiaminas/química , Micelas , Polímeros/química , Inibidores da Transcriptase Reversa/farmacocinética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Alcinos , Animais , Ciclopropanos , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Infectious diseases are a heterogeneous group of maladies that represent a serious burden to healthcare systems worldwide. Most of the available antimicrobial drugs display poor biopharmaceutical properties that compromise their effectiveness. Cyclodextrins (CDs) are cyclic oligosaccharides of glucopyranose formed by a variable number of repeating units that combine a hydrophilic surface with a hydrophobic cavity. The production of drug/CD complexes has become one of the most extensively investigated technology approaches to improve the stability, solubility, dissolution rate and bioavailability of drugs. The present work overviews the applications of CDs for the formulation of anti-infective agents along with the most relevant administration routes. Finally, an update on the complexes with CDs available on the market to treat infectious diseases is presented.
Assuntos
Anti-Infecciosos/administração & dosagem , Doenças Transmissíveis/tratamento farmacológico , Ciclodextrinas/química , Anti-Infecciosos/química , Portadores de Fármacos , HumanosRESUMO
Aiming to develop biological skin dresses with improved performance in the treatment of skin wounds, acellular collagen I scaffolds were modified with polymeric microparticles and the subsequent loading of a hydroglycolic extract of Calendula officinalis flowers. Microparticles made of gelatin-collagen were produced by a water-in-oil emulsion/cross-linking method. Thereafter, these microparticles were mixed with collagen suspensions at three increasing concentrations and the resulting mixtures lyophilized to make microparticle-loaded porous collagen scaffolds. Resistance to enzymatic degradation, ability to associate with the C. officinalis extract, and the extract release profile of the three gelatin-collagen microparticle-scaffold prototypes were assessed in vitro and compared to collagen scaffolds without microparticles used as control. Data indicated that the incorporation of gelatin-collagen microparticles increased the resistance of the scaffolds to in vitro enzymatic degradation, as well as their association with the C. officinalis flower extract. In addition, a sharp decrease in cytotoxicity, as well as more prolonged release of the extract, was attained. Overall results support the potential of these systems to develop innovative dermal substitutes with improved features. Furthermore, the gelatin-collagen mixture represents a low-cost and scalable alternative with high clinical transferability, especially appealing in developing countries.
Assuntos
Anti-Inflamatórios não Esteroides/química , Antioxidantes/química , Calendula/química , Fármacos Dermatológicos/química , Portadores de Fármacos/química , Flores/química , Extratos Vegetais/química , Administração Cutânea , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/efeitos adversos , Antioxidantes/administração & dosagem , Antioxidantes/efeitos adversos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Colágeno Tipo I/química , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/efeitos adversos , Preparações de Ação Retardada/química , Fármacos Dermatológicos/administração & dosagem , Fármacos Dermatológicos/efeitos adversos , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/efeitos adversos , Composição de Medicamentos , Estabilidade de Medicamentos , Liofilização , Gelatina/química , Camundongos , Microesferas , Extratos Vegetais/administração & dosagem , Extratos Vegetais/efeitos adversos , Pele/efeitos dos fármacos , Pele/lesões , Solubilidade , Cicatrização/efeitos dos fármacosRESUMO
The goal of this study was to investigate the electrohydrodynamic atomization (EHDA) technology to encapsulate the water-soluble antiretroviral didanosine (ddI) within poly(epsilon-caprolactone) (PCL) particles and stabilize it in the gastric medium where it undergoes fast degradation. A preliminary study employing a one-needle setup enabled the adjustment of the critical process parameters. Then, a configuration of two concentric needles named coaxial electrohydrodynamic atomization (CEHDA) led to the formation of ddI-loaded PCL microcapsules. Scanning electron microscopy analysis showed that the microparticles were spherical and with narrow size distribution. Attenuated total reflectance/Fourier transform infrared spectroscopy confirmed that most of the drug was efficiently encapsulated within the particles, whereas differential scanning calorimetry and X-ray powder diffraction revealed that the drug was preserved mainly in crystalline form. The loading capacity was relatively high (approximately 12% w/w), and the encapsulation efficiency was approximately 100%. In vitro release assays (PBS pH = 7.4) indicated that ddI was released almost completely within 2 h. Moreover, the delayed release was expected to isolate ddI from the biological fluids during the gastric transit. Finally, pharmacokinetics studies in rats showed that ddI-loaded particles lead to a statistically significant increase of the oral bioavailability of almost 4 times and a 2-fold prolongation of the half-life with respect to a ddI aqueous solution, supporting the use of CEHDA as a promising reproducible, scalable and cost-viable technology to encapsulate water-soluble drugs within polymeric particles.
RESUMO
With the aim to produce mucoadhesive polymeric micelles for drug administration by mucosal routes, chitosan-g-oligo(epsilon-caprolactone) copolymers were synthesized by the microwave-assisted ring-opening polymerization of epsilon-caprolactone using chitosan as the macroinitiator and methanesulfonic acid as the solvent, catalyst and protecting group of the amine moieties. The reaction was conducted under very mild conditions and was completed within 10 min with a monomer conversion above 90%. The grafting of oligo(epsilon-caprolactone) blocks to the free hydroxyl groups of chitosan was confirmed by ATR/FT-IR, 1H- and 13C-NMR, WAXD and thermal analysis (TGA/DSC). The molecular weight of the synthetic hybrid copolymers was determined by GPC and MALDI-ToF mass spectrometry. Polymeric micelles obtained by the solvent diffusion/evaporation method showed a spherical shape (TEM and AFM) with sizes between 111 and 154 nm and highly positive zeta potential (>+50 mV) (DLS). In addition, they displayed good cell compatibility in the human lung adenocarcinoma epithelial line, A549, and were readily up-taken by the cervical cancer cell line, HeLa. Results from the encapsulation of the antituberculosis drug, rifampicin, showed that the micelles had better performance than other nanocarriers previously investigated (e.g., cyclodextrins). Moreover, the micelles conserved the mucoadhesiveness displayed by pristine chitosan and are expected to transiently open tight cell junctions and lead to more prolonged residence times in mucosal tissues and greater drug bioavailability.
RESUMO
With the advent of the Highly Active Antiretroviral Therapy, the morbidity and the mortality associated to HIV have been considerably reduced. However, 35-40 million people bear the infection worldwide. One of the main causes of therapeutic failure is the frequent administration of several antiretrovirals that results in low patient compliance and treatment cessation. In this work, we have developed an innovative Nanoparticle-in-Microparticle Delivery System (NiMDS) comprised of pure drug nanocrystals of the potent protease inhibitor indinavir free base (used as poorly water-soluble model protease inhibitor) produced by nanoprecipitation that were encapsulated within mucoadhesive polymeric microparticles. Pure drug nanoparticles and microparticles were thoroughly characterized by diverse complementary techniques. NiMDSs displayed an encapsulation efficiency of approximately 100% and a drug loading capacity of up to 43% w/w. In addition, mucoadhesiveness assays ex vivo conducted with bovine gut showed that film-coated microparticles were retained for more than 6 h. Finally, pharmacokinetics studies in mongrel dogs showed a dramatic 47- and 95-fold increase of the drug oral bioavailability and half-life, respectively, with respect to the free unprocessed drug. These results support the outstanding performance of this platform to reduce the dose and the frequency of administration of protease inhibitors, a crucial step to overcome the current patient-incompliant therapy.