ABSTRACT
PURPOSE: In general, the surface functionalization of polymeric nanoparticles is carried out by covalently bounding ligands to the nanoparticle surface. This process can cause a lack or decrease of the ligand specificity to its target receptor, besides the need of purification steps. We proposed a ligand-metal-chitosan-lecithin complex as a new strategy to functionalize the surface of biodegradable nanoparticles. METHODS: One pot synthesis of scFv anti-LDL(-)-functionalized nanocapsules was carried out by self-assembly and interfacial reactions. Particle sizing techniques, lipid peroxidation and molecular recognition by enzyme linked immuno sorbent assays were carried out. RESULTS: The selected formulation had unimodal size distribution with mean diameter of about 130 nm. The metals in the complex did not enhance the oxidative stress, and the scFv anti-LDL(-)-functionalized nanocapsules recognized LDL(-) and did not react with native LDL indicating the maintenance of the active site of the fragment. CONCLUSIONS: The one pot synthesis, using the ligand-metal-chitosan-lecithin complex to functionalize the surface of the biodegradable nanocapsules, maintained the active site of the antibody fragment making the device interesting for applications in nanomedicine.
Subject(s)
Lipoproteins, LDL/immunology , Nanocapsules/chemistry , Nanoparticles/chemistry , Polymers/chemistry , Single-Chain Antibodies/chemistry , Single-Chain Antibodies/immunology , Catalytic Domain , Chemistry, Pharmaceutical/methods , Chitosan/chemistry , Lecithins/chemistry , Ligands , Lipid Peroxidation/drug effects , Metals/chemistry , Oxidative Stress/drug effects , Particle SizeABSTRACT
This work aimed to develop nanocapsules (NC) coated with polysorbate 80 (P80), cationic chitosan (CS) or polyethylene glycol (PEG) using clozapine (CZP) as the drug model. The zeta potential, pH and encapsulation efficiency were directly affected by the CS coating. Using the bag dialysis method, the in vitro CZP release from CS-coated nanocapsules was similar to the PEG-coated at pH 7.4. Nanocapsules coated with PEG and CS exhibited an increased action duration compared to the P80-coated nanocapsules in pseudo-psychosis induced by d,l-amphetamine in rats. When comparing both groups, the group administered CS-coated nanocapsules showed better activity than the PEG-coated nanocapsules at 6, 10 and 12h after d,l-amphetamine administration. The pharmacokinetic assessment in rats demonstrated that the observed half-lives were free CZPSubject(s)
Clozapine/chemistry
, Drug Carriers/chemistry
, Chitosan/chemistry
, Hydrogen-Ion Concentration
, Nanocapsules/chemistry
, Polyethylene Glycols/chemistry
, Polysorbates/chemistry
ABSTRACT
The hemocompatibility of nanoparticles is of critical importance for their systemic administration as drug delivery systems. Formulations of lipid-core nanocapsules, stabilized with polysorbate 80-lecithin and uncoated or coated with chitosan (LNC and LNC-CS), were prepared and characterized by laser diffraction (D[4,3]: 129 and 134 nm), dynamic light scattering (119 nm and 133 nm), nanoparticle tracking (D50: 124 and 139 nm) and particle mobility (zeta potential: -15.1 mV and +9.3 mV) analysis. In vitro hemocompatibility studies were carried out with mixtures of nanocapsule suspensions in human blood at 2% and 10% (v/v). The prothrombin time showed no significant change independently of the nanocapsule surface potential or its concentration in plasma. Regarding the activated partial thromboplastin time, both suspensions at 2% (v/v) in plasma did not influence the clotting time. Even though suspensions at 10% (v/v) in plasma decreased the clotting times (p<0.05), the values were within the normal range. The ability of plasma to activate the coagulation system was maintained after the addition of the formulations. Suspensions at 2% (v/v) in blood showed no significant hemolysis or platelet aggregation. In conclusion, the lipid-core nanocapsules uncoated or coated with chitosan are hemocompatible representing a potential innovative nanotechnological formulation for intravenous administration.
Subject(s)
Biocompatible Materials , Chitosan/toxicity , Drug Carriers , Lecithins/toxicity , Lipids/toxicity , Nanocapsules , Polyesters/toxicity , Polysorbates/toxicity , Blood Coagulation/drug effects , Chemistry, Pharmaceutical , Chitosan/chemistry , Drug Compounding , Erythrocyte Membrane/drug effects , Hemolysis/drug effects , Humans , Lecithins/chemistry , Light , Lipids/chemistry , Materials Testing , Nanotechnology , Partial Thromboplastin Time , Particle Size , Platelet Aggregation/drug effects , Polyesters/chemistry , Polysorbates/chemistry , Prothrombin Time , Scattering, Radiation , Technology, Pharmaceutical/methodsABSTRACT
Soft agglomerates containing pantoprazole-loaded microparticles were developed with the aim of prompt delivery of gastro-resistant particles. The objective was to evaluate the relative bioavailability in dogs after the oral administration of soft agglomerates. Gastro-resistant pantoprazole-loaded microparticles prepared by spray drying were mixed with mannitol/lecithin spray-dried powder and agglomerated by vibration. One single oral dose (40mg) was administered to dogs. Each dog received either a reference tablet or hard gelatin capsules containing the agglomerates. The plasma profiles were evaluated by non-compartmental and compartmental approaches, and the pharmacokinetic parameters were determined. The agglomerates presented 100% of drug particle loading and a production yield of 80.5%. The amount of drug absorbed after oral dosing was similar after reference or agglomerate administration, leading to a relative bioavailability of 108%. The absorption lag-time was significantly reduced after agglomerate administration (from 135.5+/-50.6 to 15.0+/-2.5min). The agglomerated gastro-resistant pantoprazole-loaded microparticles reduced time to peak plasma. The agglomerates were equivalent to the reference tablets in terms of extent but not in terms of rate of absorption, showing that this formulation is an alternative to single-unit oral dosing with enteric coating and with the advantage of reducing time to effect.
Subject(s)
2-Pyridinylmethylsulfinylbenzimidazoles/pharmacokinetics , Anti-Ulcer Agents/pharmacokinetics , Drug Carriers/pharmacokinetics , Drug Compounding/methods , Intestinal Absorption , Microspheres , 2-Pyridinylmethylsulfinylbenzimidazoles/administration & dosage , 2-Pyridinylmethylsulfinylbenzimidazoles/chemistry , Administration, Oral , Animals , Anti-Ulcer Agents/administration & dosage , Anti-Ulcer Agents/chemistry , Biological Availability , Dogs , Drug Carriers/administration & dosage , Drug Carriers/chemical synthesis , Pantoprazole , Particle SizeABSTRACT
Based on the structure of polymeric nanocapsules containing a lipid-dispersed core composed of caprylic/capric trygliceride (CCT) and sorbitan monostearate (SM), we hypothesized that varying the core component concentrations the drug release kinetic could be modulated. Our objective was also to determine the parameters which were responsible for controlling the drug release kinetics. The nanocapsules were prepared by interfacial deposition of poly(epsilon-caprolactone). Interfacial hydrolysis of indomethacin ester (IndOEt) was used to simulate a sink condition of release. Mathematical modeling showed that the IndOEt half-lives increased (198 to 378 and 263 to 508 min) with the increase in the core lipid concentrations, and that the release mechanism was the anomalous transport. By increasing the SM concentration, the diameters were constant (around 250 nm) and the surface areas increased (from 1.06 x 10(4) to 1.51 x 10(4) cm2 x ml(-1)), while by increasing the CCT concentration, the diameters increased (215 to 391 nm) and the surface areas reduced (1.46 x 10(4) to 1.06 x 10(4) cm2 x ml(-1)). The presence of SM increased the viscosity of CCT and the IndOEt apparent permeability decreased from 4.26 x 10(-7) to 2.54 x 10(-7) cm x s(-1), while for CCT series, the apparent permeability was constant around 3.0 x 10(-7) cm x s(-1). A mathematical correlation was established and the IndOEt apparent permeability can be estimated by the SM concentration. In conclusion, varying the CCT and SM concentrations the IndOEt release was controlled by the nanocapsule surface area and by the viscosity of the core, respectively.