Non-invasive transcutaneous influenza immunization using vaccine-loaded vaterite particles.

Transcutaneous immunization receives much attention due to the recognition of a complex network of immunoregulatory cells in various layers of the skin. The elaboration of non-invasive needle-free approaches towards antigen delivery holds especially great potential here while searching for a hygienically optimal vaccination strategy. Here, we report on a novel protocol for transfollicular immunization aiming at delivery of an inactivated influenza vaccine to perifollicular antigen presenting cells without disrupting the stratum corneum integrity. Porous calcium carbonate (vaterite) submicron carriers and sonophoresis were utilized for this purpose. Transportation of the vaccine-loaded particles into hair follicles of mice was assessed in vivo via optical coherence tomography monitoring. The effectiveness of the designed immunization protocol was further demonstrated in an animal model by means of micro-neutralization and enzyme-linked immunosorbent assays. The titers of secreted virus-specific IgGs were compared to those obtained in response to intramuscular immunization using conventional influenza vaccine formulation demonstrating no statistically significant differences in antibody levels between the groups. The findings of our pilot study render the intra-follicular delivery of the inactivated influenza vaccine by means of vaterite carriers a promising alternative to invasive immunization.

Magnetic Hyperthermia Nanoarchitectonics via Iron Oxide Nanoparticles Stabilised by Oleic Acid: Anti-Tumour Efficiency and Safety Evaluation in Animals with Transplanted Carcinoma.

In this study, we developed iron oxide nanoparticles stabilised with oleic acid/sodium oleate that could exert therapeutic effects for curing tumours via magnetic hyperthermia. A suspension of iron oxide nanoparticles was produced and characterised. The toxicity of the synthesised composition was examined in vivo and found to be negligible. Histological examination showed a low local irritant effect and no effect on the morphology of the internal organs. The efficiency of magnetic hyperthermia for the treatment of transplanted Walker 256 carcinoma was evaluated. The tumour was infiltrated with the synthesised particles and then treated with an alternating magnetic field. The survival rate was 85% in the studied therapy group of seven animals, while in the control group (without treatment), all animals died. The physicochemical and pharmaceutical properties of the synthesised fluid and the therapeutic results, as seen in the in vivo experiments, provide insights into therapeutic hyperthermia using injected magnetite nanoparticles.

Enhanced cytotoxicity caused by AC magnetic field for polymer microcapsules containing packed magnetic nanoparticles.

Magnetic hyperthermia (MH) is a perspective tool to treat the tumor while the magnetic material is delivered. The key problems in MH development is to ensure an effective local heating within cancer cell without overheating other cells. In order to do that one has to reach substantial local accumulation of magnetic nanoparticles (MNPs) and/or magnetically sensitive objects with advanced heat properties. Absorbing heat energy for destroying tumor cells can be generated only if there is sufficient amount of locally placed MNPs. In this work, we propose polyelectrolyte microcapsules modified with iron oxide nanoparticles as an approach to tie magnetic materials in high concentration locally. These microcapsules (about 3 microns in diameter) can be readily internalized by various cells. The human fibroblasts uptake of the microcapsules and cytotoxic effect upon the influence of alternating magnetic field (AMF) while magnetic capsules are inside the cells is under study in this work. The cytotoxicity of the magnetic microcapsules was compared with the cytotoxicity of the MNPs while free in the solution to evaluate the effect of bounding MNPs. A cytotoxic effect on cells was found in the case of preliminary incubation of fibroblasts with capsules while the AMF is applied. In the case of MNPs in an equivalent dose per mass of magnetic material, there was no cytotoxic effect noticed after the treatment with the field. It is noteworthy that during the treatment of cells with the AMF, the increase in temperature of the incubation medium was not registered. The morphological changes on fibroblasts were consistent with the data of the viability assessment. Thus, the synthesized capsules are shown as a means for local enhancement of magnetic hyperthermia in the treatment of tumor diseases.

Antioxidant coating of micronsize droplets for prevention of lipid peroxidation in oil-in-water emulsion.

Fast lipid peroxidation in emulsified oils results in carcinogens formation and product rancidity. Prevention of oxidative degradation in oil-in-water emulsion has been achieved by encapsulating of each droplet of dispersed phase in antioxidant multilayer coating shell. The fabrication comprised placing a surface-active ionic emulsifier at the oil/water interface followed by stepwise alternate adsorption a biocompatible polyelectrolyte and antioxidant layers. Uncoupled polyelectrolyte macromolecules and antioxidant were thoroughly removed from formulation, thus the protection was entirely attributed to the droplets' shell. The experiments were performed using linseed oil, the richest source of highly unstable omega-3 alpha linolenic essential fatty acid. Bovine serum albumin (BSA) was exploited as an anionic emulsifier. The biodegradable coating shell was formed of poly-l-arginine (PARG) and dextran sulfate (DS) applied as a polycation and a polyanion respectively. Tannic acid (TA) known as a natural antioxidant and possessing antimicrobial properties was used as a protective remedy. Oil microdroplets coated with TA-containing shell displayed physical-chemical and mechanical stability in aqueous phase and over freeze-drying process as determined by ζ-potential measurements, dynamic light scattering (DLS), and confocal laser scanning microscopy (CLSM). Oxidation of emulsified oil was monitored by formation of malondialdehyde (MDA) in the samples quantified by Thiobarbituric Acid Reactive Substances (TBARS) assay. Coating shell with an incorporated layer of TA effectively suppressed oxidation in water-dispersed oil droplets and affected iron-catalyzed oxidation over 15 days of incubation at 37 °C in 0.3 mM FeBr2 solution. Antioxidant activity of TA-containing shell assembled around each oil droplet was found to be higher than that of mixed tocopherols (MT) added to linseed oil in concentration of 10000 ppm.

Magnetic targeting and cellular uptake of polymer microcapsules simultaneously functionalized with magnetic and luminescent nanocrystals.

By using a flow channel system for modeling the bloodstream in the circulatory system and by locally creating a magnetic field gradient caused by a permanent magnet, we demonstrate specific trapping of polymer capsules simultaneously functionalized with two types of nanoparticles--magnetic and luminescent nanocrystals. In the regions where the capsules were trapped by the magnetic field, drastically increased uptake of capsules by cells has been observed. The uptake of capsules by cells could be conveniently monitored with a fluorescence microscope by the luminescence of CdTe nanocrystals that had been embedded into the shells of the capsules. Our experiments envisage the feasibility of magnetic targeting of polymer capsules loaded by pharmaceutical agents to pathogenic parts of a tissue.

Microgel-based engineered nanostructures and their applicability with template-directed layer-by-layer polyelectrolyte assembly in protein encapsulation.

A novel strategy for the fabrication of microcapsules is elaborated by employing biomacromolecules and a dissolvable template. Calcium carbonate (CaCO(3)) microparticles were used as sacrificial templates for the two-step deposition of polyelectrolyte coatings by surface controlled precipitation (SCP) followed by the layer-by-layer (LbL) adsorption technique to form capsule shells. When sodium alginate was used for inner shell assembly, template decomposition with an acid resulted in simultaneous formation of microgel-like structures due to calcium ion-induced gelation. An extraction of the calcium after further LbL treatment resulted in microcapsules filled with the biopolymer. The hollow as well as the polymer-filled polyelectrolyte capsules were characterized using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and scanning force microscopy (SFM). The results demonstrated multiple functionalities of the CaCO(3) core - as supporting template, porous core for increased polymer accommodation/immobilization, and as a source of shell-hardening material. The LbL treatment of the core-inner shell assembly resulted in further surface stabilization of the capsule wall and supplementation of a nanostructured diffusion barrier for encapsulated material. The polymer forming the inner shell governs the chemistry of the capsule interior and could be engineered to obtain a matrix for protein/drug encapsulation or immobilization. The outer shell could be used to precisely tune the properties of the capsule wall and exterior. [Diagram: see text] Confocal laser scanning microscopy (CLSM) image of microcapsules (insert is after treating with rhodamine 6G to stain the capsule wall).