Gelatin-Based Rapid Blue Light-Irradiation In Situ Gelation Hydrogel Platform for Combination Therapy in Brain Tumors

<b>Background/Objectives</b>: Glioblastoma (GBM) is a fatal tumor in the central nervous system (CNS) with a poor prognosis. Preventing tumors from post-surgical recurrence is a significant clinical challenge, since current methods deliver chemotherapeutic agents in a rapid manner and are not effective against the residual tumor cells. To address these limitations, we develop a blue light-crosslinking hydrogel which can be rapidly gelled in situ and tightly adhere on the tissues for controlled chemotherapy, radiotherapy, and enhanced laser interstitial thermal therapy (LITT) to inhibit residual tumor cells from post-surgical recurrence. <b>Methods</b>: We utilize gelatin-MA based hydrogel with crosslinker VA-086 as hydrogel scaffold to encapsulate small-molecule drugs (Epirubicin and Cisplatin) and LITT agent polypyrrole-coated graphine oxide (PPy@GO). The mixture can form into hydrogel in situ by blue light irradiation and performed chemo-LITT and radio therapy simultaneously. Then we determine the prevailing factors that affect efficient encapsulation of therapeutic agents within hydrogels, efficiency of gelation, LITT enhancement, and drug release. Then evaluate efficiency in human cancer cells and an in vivo tumor model. <b>Results</b>: Our results demonstrate that 18 wt% Gelatin MA formulation achieved >95% gelation within 2 min, with drug-loaded gels forming within 5 min. The gelation can perform both in vitro and in vivo without affect the drug efficiency. This multi-treatment system can effectively prevent tumor recurrence and significantly prolong the medium survival of glioma-bearing (MBR-614 or U87-MGFL) mice to above 65 days compared with the control group (36 days). <b>Conclusions</b>: The results demonstrated promising effect of this system as a multi-therapeutic platform which combined chemo-LITT and RT. This synergistic strategy presents a new approach to the development of a local drug delivery system for the prevention of brain tumor recurrence.