Fenton-magnetic based therapy by dual-chemodrug-loaded magnetic hydroxyapatite against colon cancer

A dual catalytic functionalized hollow mesoporous silica-based nanocarrier coated with bacteria-derived exopolysaccharides for targeted delivery of irinotecan to colorectal cancer cells

In this study, we introduced a multifunctional hollow mesoporous silica-based nanocarrier (HMSN) for the targeted delivery of irinotecan (IRT) to colorectal cancer cells. Due to their large reservoirs, hollow mesoporous silica nanoparticles are suitable platforms for loading significant amounts of drugs for sustained drug release. To respond to pH and redox, HMSNs were functionalized with cerium and iron oxides. Additionally, they were coated with bacterial-derived exopolysaccharide (EPS) as a biocompatible polymer. In vitro analyses revealed that cytotoxicity induced in cancer cells through oxidative stress, mediated by mature nanocarriers (EPS.IRT.Ce/Fe.HMSN), was surprisingly greater than that caused by free drugs. Cerium and iron ions, in synergy with the drug, were found to generate reactive oxygen species when targeting the acidic pH within lysosomes and the tumor microenvironment. This, in turn, triggered cascade reactions, leading to cell death. In vivo experiments revealed that the proposed nanocarriers had no noticeable effect on healthy tissues. These findings indicate the selective delivery of the drug to cancerous tissue and the induction of antioxidant effects due to the dual catalytic properties of cerium in normal cells. Accordingly, this hybrid drug delivery system provides a more effective treatment for colorectal cancer with the potential for cost-effective scaling up.

Hydrogel beads based on carboxymethyl cassava starch/alginate enriched with MgFe2O4 nanoparticles for controlling drug release

Implementing novel oral drug delivery systems with controlled drug release behavior is valuable in cancer therapy. Herein, a green synthetic approach based on the sol-gel technique was adopted to prepare MgFe₂O₄ nanoparticles at different calcination temperatures using citric acid as a chelating/combustion agent. In this context, pH-responsive and magnetic carboxymethyl starch/alginate hydrogel beads (CMCS-SA) containing the MgFe₂O₄ nanoparticles were developed as potential drug carriers for the anticancer drug (Doxorubicin, Dox) release in simulated gastrointestinal fluids. Furthermore, in vitro release behaviors validated that these beads illustrated excellent stability in the simulated stomach liquids. In contrast, the data in simulated intestinal fluids showed sustained release of Dox because of their pH-sensitive swelling characteristics. Notably, applying an external magnetic field (EMF) could accelerate drug release from the beads. The in vitro release of drugs from gel beads was mainly accomplished by a combination of diffusion, swelling and erosion. Moreover, the cell cytotoxicity test and laser confocal results showed no harmful effects on normal cells (3T3) but were significant cytotoxic to colon cancer cell lines (HCT116) by drug-loaded hydrogel beads. Therefore, the prepared gel beads could be qualified as latent platforms for controlling the release of anticancer drugs in cancer treatment.