Local administration of an anti-cancer drug using tissue adhesive microparticles based on hydrophobically modified Alaska pollock gelatin for post-surgical cancer chemotherapy.

Despite using endoscopic submucosal dissection to remove tumor tissues or cells, disease recurrence can sometimes occur from residual cancer cells. Although chemotherapy using anti-cancer drugs has been the gold standard, the systemic effects of the drug can lead to side effects, emphasizing the importance of local cancer treatment. However, local administration of anti-cancer drugs to the wet gastrointestinal tissue has been challenging. In this study, we developed a mixed powder composed of paclitaxel microcrystals (PTXMCs) and tissue adhesive microparticles using hydrophobically modified Alaska pollock gelatin microparticles (C10MP), named PTX/C10MP. After hydration for colloidal gel formation, the PTX/C10MP colloidal gel exhibited high tissue adhesion strength and underwater stability to cover gastrointestinal tissues. By immersing this colloidal gel in phosphate buffer solution, PTXMCs were continuously released for up to 18 days. In vivo colon cancer-bearing mouse model experiments revealed that using the PTX/C10MP colloidal gel significantly suppressed cancer growth at 12 days: 1259 ± 135 and 470 ± 151 mm for untreated and treated group and improved the survival probability at 18 days: 33 % and 100 % for untreated and treated group. Therefore, our data demonstrate that PTX/C10MP can adhere to the desired gastrointestinal tissue and enable local administration of an anti-cancer drug to kill residual cancer cells following gastrointestinal surgery.