Chemo-Photothermal Therapy on Breast Cancer Cells in a 3D Coculture Hydrogel Model with <i>In Situ</i> Embedded Polydopamine Nanoparticle

Breast cancer is one of the most common cancers in the world. Surgery is the preferred treatment for this cancer, but the risk of local recurrence and metastasis of the remaining cells after surgery is still a significant concern. A coculture 3D model based on dopamine-grafted alginate (Alg-DA) containing different polydopamine nanoparticles (PDA NPs) is presented in this work for breast cancer cell therapy. The PDA NPs were grown in situ in the hydrogels to fabricate ADHG-PDAN-x hydrogels, in which x indicates the PDA NP content. The human breast cancer line of MDA-MB-231 and primary human foreskin fibroblast cells (HFF) were cocultured in the hydrogels to closely resemble the in vivo breast tumor microenvironment. The coculture 3D hydrogel models were treated by applying an anticancer drug, docetaxel (chemotherapy), near-infrared (NIR) irradiation using a laser with an 808 nm wavelength with a power of 1 W/cm2 (photothermal therapy), and a combination of both methods (chemo-photothermal therapy). The results unveiled an increased effect of chemo-photothermal therapy on the 67.4% eradication of cancerous cells, while only chemotherapy and photothermal therapy showed 48.4% and 57.8% eradication rates, respectively. This therapeutic method can potentially prevent the growth of tumor cells and can be used after surgery to eliminate residual cancer cells.