Preparation and drug loading behavior of pH-responsive Fe3O4/CMCS/ALS magnetic nanoparticles

In order to improve the utilization of anti-tumor drugs, a magnetic delivery system for targeted drug was reported. Firstly, aminated modified sodium lignosulfonate (ALS) and carboxymethyl chitosan (CMCS) were used to fabricate nano Fe 3 O 4 to obtain pH-responsive Fe 3 O 4 /CMCS/ALS magnetic nanoparticles. Then the magnetic 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 drug loading capacity, good magnetic and pH responsiveness, with an isoelectric point of 4. 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 Fe 3 O 4 /CMCS/ALS-DOX could release 63.14%, 56.71%, and 14.28% of DOX at pH 4, 5.3, and 7.4, respectively. The results showed that the Fe 3 O 4 /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. So it could be used as a potential drug carrier.