pH-responsive magnetic FeO/carboxymethyl chitosan/aminated lignosulfonate nanoparticles with uniform size for targeted drug loading.

In order to improve the effect of anti-tumor drugs, a magnetic delivery system for targeted drug was reported. Firstly, aminated lignosulfonate (ALS) and carboxymethyl chitosan (CMCS) were used to fabricate nano FeO to obtain pH-responsive magnetic FeO /CMCS/ALS nanoparticles. Then the nanoparticles were loaded with doxorubicin hydrochloride (DOX), realizing the targeted delivery and controlled release of anti-tumor drugs. It was found that the amount of crosslinking agent and emulsifier were the key factors affecting the morphology and size of the magnetic nanoparticles. Under optimized conditions, the particle size was about 79.9-169.9 nm, exhibiting excellent pH responsiveness. When the drug-to-material ratio was 11:10, the DOX loading rate and the encapsulation rate of the nanoparticles was 48.68 % and 86.23 %. While the FeO /CMCS/ALS-DOX particles could release 63.14 %, 56.71 %, and 14.28 % of DOX at pH 4.0, 5.3, and 7.4, respectively. The results showed that the FeO /CMCS/ALS particles exhibited excellent drug loading and release behavior based on the pH responsiveness, which could be described by Langmuir adsorption model and Fick's law of diffusion respectively. MTT assay and Live/dead staining experiments also showed that the drug-loaded particles had obvious growth inhibition on cancer cells.