Hydrogels Activated with Plant Extracts/Bioactive Compounds for Cancer Treatment: From Design to Application

Plant extracts and plant-derived bioactive compounds are considered important natural agents in cancer research due to their antiproliferative, pro-apoptotic, antioxidant, anti-inflammatory, and anti-angiogenic effects. However, the low solubility, limited bioavailability, instability, and challenges in their standardization directly limit their therapeutic use. Therefore, the development of new delivery systems has become necessary. In this context, hydrogels are among the biomaterial platforms gaining attention in cancer treatment. This review provides a comprehensive assessment of the potential of hydrogel systems containing plant extracts and plant-derived bioactive compounds in cancer treatment. The article discusses cancer types, the limitations of current treatments, mechanisms of action of plant-derived bioactive compounds against cancer, stimulus-responsive hydrogel systems, and the design criteria for extract-loaded hydrogels. In addition, hydrogel systems containing plant-derived components and combination approaches that use these components alongside anticancer drugs have been investigated. According to the literature, these compounds may increase anticancer activity through local, prolonged release, reduce the toxicity of chemotherapeutic agents in some cases, and exhibit complementary or synergistic antitumor effects with chemotherapeutic drugs. They also point out the potential of treatment strategies targeting the tumor microenvironment. However, researchers need to conduct more comprehensive studies on extraction standardization, biosafety, release kinetics, in vivo efficacy, and clinical scalability. In conclusion, hydrogel systems containing plant extracts and plant-derived bioactive compounds should be considered not as direct alternatives to cancer treatments but as rational biomaterial platforms that enable controlled release, local application, and combination therapies.