No abstract

Long‐term accumulation of adenosine (Ado) in tumor tissues helps to establish the immunosuppressive tumor microenvironment and to promote tumor development. Regulation of Ado metabolism is particularly pivotal for blocking Ado‐mediated immunosuppression. The activity of adenosine kinase (ADK) for catalyzing the phosphorylation of Ado plays an essential role in regulating Ado metabolism. Specifically, accumulated Ado in the tumor microenvironment occupies the active site of ADK, inhibiting the phosphorylation of Ado. Phosphate can protect ADK from inactivation and restore the activity of ADK. Herein, calcium phosphate‐reinforced iron‐based metal‐organic frameworks (CaP@Fe‐MOFs) are designed to reduce Ado accumulation and to inhibit Ado‐mediated immunosuppressive response in the tumor microenvironment. CaP@Fe‐MOFs are found to regulate the Ado metabolism by promoting ADK‐mediated phosphorylation and relieving the hypoxic tumor microenvironment. Moreover, CaP@Fe‐MOFs can enhance the antitumor immune response via Ado regulation, including the increase of T lymphocytes and dendritic cells and the decrease of regulatory T lymphocytes. Finally, CaP@Fe‐MOFs are used for cancer treatment in mice, alleviating the Ado‐mediated immunosuppressive response and achieving tumor suppression. This study may offer a general strategy for blocking the Ado‐mediated immunosuppression in the tumor microenvironment and further for enhancing the immunotherapy efficacy in vivo.

The levels of some biomolecules and ions in the body are usually related to the structural and functional changes of cells, tissues, organs, etc., which directly affect the prevention, diagnosis, and treatment of diseases. Therefore, in vivo bioassays of these substances are of great significance in medical and healthcare fields. The nano fluorescent probes consisted of rare earth nano materials have advantages of high sensitivity, simplicity, efficiency, and strong anti-interference ability, thus showing great potential in bioassays. The functionalization of aptamers on rare earth nanomaterials can further provide better specific recognition ability and biocompatibility for nano fluorescent probes, thereby enhancing their bioassays ability in complex samples. In this paper, the research progress of aptamer-functionalized rare earth nanomaterials as nano fluorescent probes in the field of bioassays is reviewed, and the main types, properties, detection mechanisms and detection substances are briefly introduced.