Introduction
Thermoresponsive hydrogels are gels which have different properties at varying temperatures. The objective of this study was to assess the material characteristics, imaging properties and chemotherapeutic drug release profile of a novel radiopaque thermoresponsive hydrogel, which is liquid at room temperature but solidifies at body temperature, to determine potential suitability for intratumoral delivery.
Materials and Methods
An iodinated radiopaque thermoresponsive hydrogel was formulated using iodixanol at a range of concentrations and assessed for sol-gel transition, radiopacity and imaging using CT and US. A lead formulation containing 9.22% w/w iodixanol was evaluated for injectability, disintegration and dual drug release of cisplatin and paclitaxel from the hydrogel formulation.
Results
Radiopacity of the hydrogel increased in a concentration dependent manner but higher concentrations of iodixanol adversely affected the sol-gel transition of the hydrogel, therefore 9.22%w/w iodixanol hydrogel was identified as the lead formulation. This formulation was readily visible on both CT and US. The formulation was hand-injectable through a range of clinically relevant devices, had a sustained disintegration profile for up to 28 days, and was able to deliver a sustained release of chemotherapeutic drug for up to 10 days.
Discussion
Favourable imaging and material characteristics of this thermoresponsive gel are demonstrated, suggesting potential interventional oncology applications for image-guided intratumoral delivery of sustained-release chemotherapy
