Carbon dot-based nanohybrids for tumor microenvironment-activated cancer theranostics

The complex tumor microenvironment and tumor self-protection limit the efficacy of anticancer drugs, impeding clinical translation. Designing intelligent nanomedicines that integrate diagnosis and therapy is pivotal for advancing cancer treatment. Carbon dots (CDs), with tunable fluorescence and versatile surface chemistry, have been used in diagnosis and therapy. These properties enable CD-based nanohybrids to deliver precise, image-guided tumor therapy. This review summarizes the history of CDs, the construction of CD-based nanohybrids, and their applications in tumor microenvironment–activated, image-guided cooperative tumor therapies. Finally, we discuss future research directions and clinical translation challenges. We aim to inform the rational design of CD-based nanohybrids for precise tumor treatment. • In contrary to versatile applications of CDs their small size limits their function. • Construction of CD-based nanohybrids with itself or with other materials like dendrimers, nanogels, MOF, and metal ions become popular • Nanohybrids are mostly TME responsive for varying ways of tumor treatment, including imaging-guided CDT/PDT/PTT, chemotherapy and immunotherapy. • Small size challenges to their medical applications due to quick metabolism and limited EPR-based passive tumor-targeting impact and way forward discussed. • Future outlooks proposed to enhance CD-based nanohybrids for TME responsive therapy.