Bacillus spore-based oral carriers loading curcumin for the therapy of colon cancer

Oral drug delivery has attracted substantial attention due to its advantages over other administration routes. Bacillus spores, as oral probiotic agents, are applied widely. In this paper, a novel Bacillus spore-based oral colon targeted carrier loading curcumin was developed for colon cancer treatment. Curcumin was linked covalently with the outer coat of Bacillus spore and folate, respectively (SPORE-CUR-FA). Bacillus spores are capable of delivering drugs to the colon area through gastric barrier, taking the advantage of its tolerance to the harsh conditions and disintegration of the outer coat of spores after germination in the colon. The drug release in vitro and in vivo of SPORE-CUR-FA was investigated. Results showed that SPORE-CUR-FA had the characteristics of colon-targeted drug release. Pharmacokinetic studies confirmed that Bacillus spore-based carriers could efficiently improve the oral bioavailability of curcumin. In vitro and in vivo anti-tumor studies showed that SPORE-CUR-FA had substantial ability for inhibiting colon cancer cells. These findings suggest that this Bacillus spore-based oral drug delivery system has a great potential for the treatment of colon cancer.