A photoarchitectonic hydrogel for synergistic in vitro chemo–phototherapy of breast cancer

Currently, combinatorial therapy has evoked interest in cancer treatment, and may promote achieving a synergistic effect using cancer medicines. Laser-assisted and pH-responsive therapies have attracted significant attention, and their combination leads to high efficiency cancer treatment. Herein, we developed a chemo–phototherapeutic hydrogel comprised of doxorubicin (DOX, a chemotherapeutic drug) and zinc phthalocyanine (ZnPc, a phototherapeutic drug) for combinatorial and synergistic treatment of breast cancer. Firstly, we have developed carbon dots (CDs, size of ∼5 nm) utilizing lignin and folic acid as biocompatible sources. Then doxorubicin was loaded on the surface of the carbon dots via conjugation (DOX@CDs). Later on, zinc phthalocyanine and acrylic acid derivatives were utilized to develop a laser-responsive hydrogel (ZnPc-PP H). Afterward, doxorubicin-conjugated carbon dots were incorporated into the photoarchitectonic hydrogel to develop a chemo–phototherapeutic drug-loaded hydrogel (DOX@CDs–ZnPc-PP H). Subsequently, the in vitro pH-triggering experiments demonstrated that the hydrogel loaded with both DOX and ZnPc could release the drugs in an acidic environment. Interestingly, in vitro assays confirmed that DOX@CDs–ZnPc-PP H could effectively target breast cancer cells (MCF-7). Furthermore, the developed chemo–phototherapeutic hydrogel exhibited non-cytotoxic behavior. Owing to laser assisted reactive oxygen species generation from ZnPc present in the hydrogel, the growth of MCF-7 cells was significantly lowered. In conclusion, all experimental outcomes indicate that the photoarchitectonic hydrogel has the potential to be applied in synergistic chemo- and photodynamic therapy of cancer.