Hydrazidomethyl starch as a pH-sensitive coating for magnetic core in tailored magnetic nanoparticles with selective doxorubicin release.

The work aimed to use and modify starch as a biodegradable and biocompatible polysaccharide to create a modern pH-sensitive anticancer drug carrier based on a hydrazone bond. The multi-step reaction created a material that can bind to the carbonyl group of anticancer drugs. Additionally, polysaccharide was used to coat magnetic nanoparticles to increase the applicability of the carrier system. At each synthesis stage, the material was characterized in detail by performing FTIR-ATR spectra, thermal analysis, XRD, and SEM photos. In the next step, doxorubicin was loaded with a maximum of 19 % drug loading to the carrier via hydrazone bond. In the last research stage, the carrier-hydrazone bond-drug system was tested in solutions with different pH values, imitating the environments of a cancer cell, a healthy cell, and their subcellular elements regarding drug release from the carrier. The obtained release results indicate a >4-fold increase in the amount of drug released from the carrier in conditions of a slightly lower pH environment (70 %), compared to neutral pH (15 %). This represents a promising potential for using the material as an intelligent drug delivery system (DDS).