Hydrogels as local depots for on-demand therapeutic delivery: potential therapeutic approaches for tumor metastasis

Abstract

Tumor metastasis, the spread of tumor cells from their place of origin to surrounding tissues and then distant organs through vasculatures, is the major cause of cancer mortality. Despite the recent advances in therapeutic approaches for tumor metastasis, the therapeutic efficacy is still unsatisfactory. Fruitful treatment strategies for tumor metastasis largely depend on targeting tumor cells, the molecular and cellular features of circulating tumor cells, the TME, and the regulatory components of the TME. However, traditionally administered therapeutic agents in biological fluids are highly prone to inactivation, often fail to reach the target site, cause adverse effects, and exhibit poor pharmacokinetics with a short half-life. To overcome these limitations, hydrogel-based delivery systems are investigated as local depots for sustained and stable release to combat tumor metastasis. Herein, we review the extensive application of hydrogels in the local delivery systems of potential therapeutic agents for tumor metastasis therapy. This review summarizes the recent advances in tumor metastasis inhibition strategies and potential therapeutic approaches using hydrogels for the local delivery of various therapeutic agents.