Advancements of algae-involved cancer treatment

Algae, especially microalgae, are versatile in terms of nutrition, feed, biofertilizers, biofuel, and so on. In the realm of oncotherapy, algal extracts have been extensively used as anti-cancer active ingredients; however, what has been ignored is the anti-cancer value induced by themselves. Thanks to their unparalleled advantages, for example, intrinsic tumor homing, immunogenicity, and <i>in situ</i> production of anti-cancer agents, algae pave a new way in anti-cancer research. Algae have been reported about selective cytotoxicity to cancer cells and could work for oxygen-dependent strategies such as photodynamic therapy, owing to their natural photosynthetic abilities. Interestingly, integrating with customized nanomaterials (NMs), algae have been demonstrated to have unprecedented potential in overcoming barriers to existing treatment methods. Thus, in this review, starting from the classification of algae, the diverse effects of algae are thoroughly introduced, followed by the current engineering strategies of algae; lastly, the emerging development of algae-based therapeutics is timely summarized with an emphasis on the intelligent creation of biohybrid systems by choosing algae and tailored NMs. This review presents a comprehensive exploration of engineered algae-involved innovative cancer therapy, with a discussion of the future challenges and outlook, which will help design creative therapy paradigms and facilitate their clinical applications.