Biopolymeric nanogel delivery of doxorubicin induces apoptosis and inhibits growth of colon cancer cells through modulating Bax/Bcl2 ratio, AKT/PTEN, and activating Caspase-3.

BACKGROUND

Colorectal cancer (CRC) remains one of the leading causes of cancer-related deaths, underscoring the urgent need for improved therapeutic strategies that enhance efficacy while reducing systemic toxicity.

METHODS

This study presents the development of a novel folate receptor (FR)-targeted chitosan nanogel (FA-DOX-Ng) designed for targeted delivery of doxorubicin (DOX) to colorectal cancer cells. The nanogel was synthesized via ionic gelation to ensure controlled particle size and high drug loading capacity.

RESULTS

The synthesized FA-DOX-Ng exhibited a hydrodynamic diameter of 233 ± 32 nm, pH-responsive release behavior, and a loading efficiency of 43.2 ± 2.3 %. In vitro tests using HT-29 colorectal cancer cells revealed that FA-DOX-Ng markedly enhanced therapeutic effectiveness, leading to a 280-fold reduction in IC50 values (250 ng/mL for FA-DOX-Ng vs. 70 µg/mL for free DOX) and a therapeutic index of 4.0 (compared to 1.0 for free DOX). Real-time PCR analysis indicated upregulation of pro-apoptotic genes (PTEN, BAX, Caspase-8/9/3) and downregulation of anti-apoptotic genes (AKT, Bcl-2), confirming activation of the intrinsic apoptotic pathway. Flow cytometry analysis further demonstrated that FA-DOX-Ng induced apoptosis in 51.5 % of HT-29 cells, with minimal necrosis (2.2 %). Additionally, the nanogel showed high biocompatibility with normal HUVEC cells.

CONCLUSION

These results highlight FA-DOX-Ng as an innovative, FR-targeted drug delivery platform capable of enhancing the anticancer efficacy of DOX while minimizing systemic toxicity in colorectal cancer therapy.