In the present study, we report the properties of a mucoadhesive chitosan-pectinate nanoparticulate formulation able to retain its integrity in the milieu of the upper gastrointestinal tract and subsequently, mucoadhere and release curcumin in colon conditions. Using this system, we aimed to deliver curcumin to the colon for the possible management of colorectal cancer. The delivery system comprised of a chitosan-pectinate composite nanopolymeric with a z-average of 206.0 nm (±6.6 nm) and zeta potential of +32.8 mV (±0.5 mV) and encapsulation efficiency of 64%. The nanoparticles mucoadhesiveness was higher at alkaline pH compared to acidic pH. Furthermore, more than 80% release of curcumin was achieved in pectinase-enriched medium (pH 6.4) as opposed to negligible release in acidic and enzyme-restricted media at pH 6.8. SEM images of the nanoparticles after exposure to the various media indicate a retained matrix in acid media as opposed to a distorted/fragmented matrix in pectinase-enriched medium. The data strongly indicates that the system has the potential to be applied as a colon-targeted mucoadhesive curcumin delivery system for the possible treatment of colon cancer.
Curcumin, the active ingredient of the rhizome curcuma longa has been extensively studied as an anticancer agent for various types of tumours. However, its efficacy as an anticancer agent is restricted due to poor absorption from the gastrointestinal tract, rapid metabolism and degradation in acidic medium. In the present study, we encapsulated curcumin in chitosan-pectinate nanoparticulate system (CUR-CS-PEC-NPs) for deployment of curcumin to the colon, whereby curcumin is protected against degradative effects in the upper digestive tract, and hence, maintaining its anticancer properties until colon arrival. The CUR-CS-PEC-NPs was taken up by HT-29 colorectal cancer cells which ultimately resulted in a significant reduction in cancer cell propagation. The anti-proliferative effect of the encapsulated curcumin was similar to that of free curcumin at equivalent doses which confirms that the encapsulation process did not impede the anticancer activity of curcumin. The oral bioavailability (Cmax, and AUC) of curcumin in CUR-CS-PEC-NPs was enhanced significantly by 4-folds after 6 hours of treatment compared to free curcumin. Furthermore, the clearance of curcumin from the CUR-CS-PEC-NPs was lower compared to free curcumin. These findings point to the potential application of the CUR-CS-PEC-NPs in the oral delivery of curcumin in the treatment of colon cancer.