The rising global burden of cancer necessitates innovative therapeutic strategies, with immunotherapy demonstrating remarkable potential. However, its clinical efficacy remains limited by low response rates and non-specific (off-target) delivery. This review highlights natural polymer-based hydrogels as emerging delivery platforms engineered to enhance the efficacy of cancer immunotherapy. These hydrogels exploit the biocompatibility and biodegradability of natural polymers, employing chemical or physical crosslinking to encapsulate and deliver immunotherapeutic agents. The versatility of these hydrogels is discussed in the context of oral, sprayable, injectable, and implantable formulations, which are adaptable to specific tumor sites. Their responsiveness to stimuli such as pH, temperature, and enzymatic activity enables controlled and sustained release of immunotherapeutic agents, including checkpoint inhibitors, cytokines, and Toll-like receptor agonists. These hydrogels can also modulate the tumor microenvironment by regulating pH, oxygen levels, and immune cell infiltration, thereby enhancing therapeutic efficacy. Moreover, immunotherapeutic hydrogels can act synergistically with chemotherapy, radiotherapy, and phototherapies to enhance antitumor immune responses. Despite their potential, challenges such as degradation kinetics, bioactivity retention, and regulatory hurdles must be addressed to ensure successful clinical translation. This review provides insights into the rational design, development and application of stimuli-responsive hydrogels as next-generation platforms for effective cancer immunotherapy.

Annexin A1, a well-known endogenous anti-inflammatory mediator, plays a critical role in a variety of pathological processes. Fibrosis is described by a failure of tissue regeneration and contributes to the development of many diseases. Accumulating evidence supports that Annexin A1 participates in the progression of tissue fibrosis. However, the fundamental mechanisms by which Annexin A1 regulates fibrosis remain elusive, and even the functions of Annexin A1 in fibrotic diseases are still paradoxical. This review focuses on the roles of Annexin A1 in the development of fibrosis of lung, liver, heart, and other tissues, with emphasis on the therapy potential of Annexin A1 in fibrosis, and presents future research interests and directions in fibrotic diseases.