Activity of Povidone in Recent Biomedical Applications with Emphasis on Micro- and Nano Drug Delivery Systems.

Due to the unwanted toxic properties of some drugs, new efficient methods of protection of the organisms against that toxicity are required. New materials are synthesized to effectively disseminate the active substance without affecting the healthy cells. Thus far, a number of polymers have been applied to build novel drug delivery systems.

Degradable nanohydrogel with high doxorubicin loadings exhibiting controlled drug release and decreased toxicity against healthy cells.

A new nanogel/drug carrier of 100-150 nm size, based on poly(N-isopropylacrylamide-co-sodium acrylate) and degradable crosslinker (cystine derivative), was synthesized. Using the electrostatic interactions between the carboxylic groups in the polymer network and the protonated amine groups of doxorubicin it was possible to load the drug into the carrier to a very high level of 28-30% relative to the dry mass of the polymer. The presence of the -S-S- groups made the polymer network susceptible to degradation by glutathione.

Degradable, thermo-, pH- and redox-sensitive hydrogel microcapsules for burst and sustained release of drugs.

Polymer microcapsules offer a possibility of storing increased amounts of drugs. Appropriate design and composition of the microcapsules allow tuning of the drug-release process. In this paper, we report on synthesis of hydrogel microcapsules sensitive to temperature and pH and degradable by glutathione and hydrogen peroxide.