Injectable hydrogel-based drug delivery systems for enhancing the efficacy of radiation therapy: A review of recent advances

Radiotherapy(RT) is a crucial treatment for cancer; however, its effectiveness is limited by adverse effects on normal tissues, radioresistance, and tumor recurrence. To overcome these challenges, hydrogels have been employed for delivery of radiosensitizers and other therapeutic agents. This review summarizes recent advancements in the application of hydrogel-based local drug delivery systems for improving the therapeutic efficacy of RT in cancer treatment. Firstly, we introduce the classification and properties of hydrogels. Next, we detail hydrogel-based platforms designed to enhance both external beam radiation therapy and brachytherapy. We also discuss hydrogels used in combination therapy involving RT and immunotherapy. Lastly, we highlight the challenges that hydrogels face in RT. By surveying the latest developments in hydrogel applications for RT, this review aims to provide insights into the development of more effective and targeted cancer therapies.