Doxorubicin loading and in vitro release from poly(alkylcyanoacrylate) nanoparticles produced by redox radical emulsion polymerization

Functionalized Particles Designed for Targeted Delivery

Pure bioactive compounds alone can only be exceptionally administered in medical treatment. Usually, drugs are produced as various forms of active compounds and auxiliary substances, combinations assuring the desired healing functions. One of the important drug forms is represented by a combination of active substances and particle-shaped polymer in the nano- or micrometer size range. The review describes recent progress in this field balanced with basic information. After a brief introduction, the paper presents a concise overview of polymers used as components of nano- and microparticle drug carriers. Thereafter, progress in direct synthesis of polymer particles with functional groups is discussed. A section is devoted to formation of particles by self-assembly of homo- and copolymer-bearing functional groups. Special attention is focused on modification of the primary functional groups introduced during particle preparation, including introduction of ligands promoting anchorage of particles onto the chosen living cell types by interactions with specific receptors present in cell membranes. Particular attention is focused on progress in methods suitable for preparation of particles loaded with bioactive substances. The review ends with a brief discussion of the still not answered questions and unsolved problems.

Preparation of silver nanoparticles in a high voltage AC arc in water

The article presents for the first time the synthesis of silver nanoparticles in an electric arc of high-voltage alternating current with a frequency of 50 Hz. In particular, the method and apparatus necessary for the preparation of nanoparticles in water solution is discussed. Current–voltage characteristics depending on the mutual distance between the electrodes are presented which show a very high stability of the generated discharge phenomena. The obtained nanoparticles were examined using various analytical techniques such as UV–Vis spectroscopy, dynamic light scattering (DLS), zeta potential, energy dispersive X-Ray analysis (EDS), X-ray diffraction (XRD), and X-ray fluorescence (EDXRF). The morphology, surface and size of the obtained nanoparticles was carried out using transmission electron microscopy (TEM) and scanning TEM (STEM) equipped with the annual dark-field imaging scanning atomic-scale chemical mapping (STEM). The designed simple power supply unit consisting of an autotransformer and a microwave oven transformer (MOT) makes the preparation of silver nanoparticles both simple and economical.

Emulsion and miniemulsion techniques in preparation of polymer nanoparticles with versatile characteristics

In recent years, polymer nanoparticles (PNPs) have found their ways into numerous applications extending from electronics to photonics, conducting materials to sensors and medicine to biotechnology. Physical properties and surface morphology of PNPs are the most important parameters that significantly affect on their exploitations and can be controlled through the synthesis process. Emulsion and miniemulsion techniques are among the most efficient and wide-spread methods for preparation of PNPs. The objective of this review is to present and highlight the recent developments in the advanced PNPs with specific properties that are produced through emulsion and miniemulsion processes.

Drug carriers in osteoporosis: preparation, drug encapsulation and applications

Carriers are largely used to enhance therapy efficiency via the encapsulation of active molecules. The encapsulation enhances the stability of drug molecules, improves the targeting properties and prolongs pharmacological activity via continuous local release of active molecules. The aim of this review is to report the carrier systems used in osteoporosis therapy. This state of the art research has mainly focused on describing all types of carriers used in this area, their elaboration and properties, the drug characteristics used in such specific application, and drug release and efficiency. In this field, various processes have been used in order to obtain well-defined capsules, spheres and more complex carriers. In this exhaustive review, each process is described, illustrated and discussed.

Conformation of surface-decorating dextran chains affects the pharmacokinetics and biodistribution of doxorubicin-loaded nanoparticles

Recent reports showed that subtle modifications of nanoparticle surface properties induced dramatic changes of interactions with serum proteins. The present work was aimed to investigate the effect of the conformation of dextran chains decorating the surface of poly(alkylcyanoacrylate) (PACA) nanoparticles on the pharmacokinetic and biodistribution of a model drug associated with the nanoparticles. Doxorubicin was associated with PACA nanoparticles prepared by anionic emulsion polymerization (AEP) (Dox-AEP) and redox radical emulsion polymerization (RREP) (Dox-RREP). Nanoparticles and the free drug (f-Dox) were injected intravenously to rats to determine the pharmacokinetic and biodistribution of doxorubicin. Curves of the pharmacokinetics showed a rapid phase of distribution followed by a slower elimination phase. Pharmacokinetic parameters of the distribution phase determined for the Dox-RREP were significantly different from those of f-Dox and Dox-AEP, while no difference was observed in the elimination phase of the three formulations. Rats treated with Dox-RREP showed lower Dox concentrations in liver but higher concentrations in heart, lungs, and kidneys compared to those treated with the other formulations. Dox-RREP exhibited a new type of stealth behavior characterized by a short circulation time and a rapid distribution in highly vascularized organs bypassing the MPS. The difference in pharmacokinetic and biodistribution observed between the drugs formulated with the two types of nanoparticles was attributed to the difference in the conformation of the dextran chains stranded on the nanoparticle surface.