Recent progress of hydrogel-based local drug delivery systems for postoperative radiotherapy

Abstract

Surgical resection and postoperative radiotherapy remained the most common therapeutic modalities for malignant tumors. However, tumor recurrence after receiving such combination is difficult to be avoided because of high invasiveness and radiation resistance of cancer cells during long-term therapy. Hydrogels, as novel local drug delivery systems, presented excellent biocompatibility, high drug loading capacity and sustained drug release property. Compared with conventional drug formulations, hydrogels are able to be administered intraoperatively and directly release the entrapped therapeutic agents to the unresectable tumor sites. Therefore, hydrogel-based local drug delivery systems have their unique advantages especially in sensitizing postoperative radiotherapy. In this context, classification and biological properties of hydrogels were firstly introduced. Then, recent progress and application of hydrogels for postoperative radiotherapy were summarized. Finally, the prospects and challenges of hydrogels in postoperative radiotherapy were discussed.

Formation of Zwitterionic and Self-Healable Hydrogels via Amino-yne Click Chemistry for Development of Cellular Scaffold and Tumor Spheroid Phantom for MRI

“…Hydrogel-based materials, characterized by their high water content, transparency, biocompatibility, and resemblance to the extracellular matrix, − have gained prominence in various biological applications such as drug delivery, 3D scaffolds, injectable tissue engineering, surgical glues, and tissue sealants. − For example, hydrogel-based delivery systems have been designed to encapsulate and deliver bioactive factors such as macromolecules, drugs, and cells, and enhance their distribution to specific targets . Cell encapsulation within hydrogels is especially promising, providing environments that support normal cell function and protect them from external factors .…”

“… 5 − 10 For example, hydrogel-based delivery systems have been designed to encapsulate and deliver bioactive factors such as macromolecules, drugs, and cells, and enhance their distribution to specific targets. 11 Cell encapsulation within hydrogels is especially promising, providing environments that support normal cell function and protect them from external factors. 12 However, the gelation process, material compositions, and mechanical properties of hydrogels affect the loading ability as well as cell viability, which tend to limit the practical application of hydrogels ( Table S1 ).…”