Shellac Micelles Loaded with Curcumin Using a pH Cycle to Improve Dispersibility, Bioaccessibility, and Potential for Colon Delivery

Abstract

Delivery systems smaller than 50 nm are advantageous for cancer prevention. In this study, curcumin was dissolved in shellac micelles following co-dissolving at pH 13.0 and neutralization using glucono-delta-lactone. With 5% w/v shellac and 0.5−5 mg/mL curcumin, the loading capacity and encapsulation efficiency were up to 8.0 and 92.6%, respectively, and the nanocapsules had an average diameter of 20 nm. Differential scanning calorimetry, FTIR spectroscopy, and fluorescence spectroscopy results confirmed the encapsulation of curcumin in an amorphous state in shellac micelles. The neutral nanocapsule dispersions maintained the particle dimension and had less than 10% curcumin degradation during 4 week storage at 4 °C. Nanoencapsulating curcumin enhanced in vitro bioavailability and antiproliferation activity against colon cancer cells. After simulated digestions, ∼60% of the nanoencapsulated curcumin was not available for intestinal absorption, nanocapsules retained their structure, and nanoencapsulated curcumin remained active against colon cancer cells, indicating the potential delivery for colorectal cancer prevention.

Structured soft particulate matters for delivery of bioactive compounds in foods and functioning in the colon

“…105 For shellac and curcumin co-dissolved at pH 12.0, the self-assembled micellar structures after neutralization to pH 7.0 had a diameter of 14.1-38.3 nm, larger at a higher curcumin load. 105 After the SGD and SID, about 40% of curcumin was present in the supernatant phase with bile salts after centrifugation, i.e., bioaccessibility, micellar structures were observed, and the digesta remained active against the proliferation of human CRC cells. 105 Co-encapsulation of curcumin and quercetin in shellac micelles enabled the synergistic antioxidant and cytotoxic properties of the polyphenols, while maintaining the characteristics feasible for colon delivery.…”

“…82 When dissolved at pH 12.0, the intermolecular ester bonds in the oligomeric shellac are cleaved, and the monomeric shellac forms micelles. 105 For shellac and curcumin co-dissolved at pH 12.0, the self-assembled micellar structures after neutralization to pH 7.0 had a diameter of 14.1–38.3 nm, larger at a higher curcumin load. 105 After the SGD and SID, about 40% of curcumin was present in the supernatant phase with bile salts after centrifugation, i.e.…”

“…105 After the SGD and SID, about 40% of curcumin was present in the supernatant phase with bile salts after centrifugation, i.e., bioaccessibility, micellar structures were observed, and the digesta remained active against the proliferation of human CRC cells. 105 Co-encapsulation of curcumin and quercetin in shellac micelles enabled the synergistic antioxidant and cytotoxic properties of the polyphenols, while maintaining the characteristics feasible for colon delivery. 106 Curdlan was hydrolysed to form oligosaccharides that were further modified with hydrophobic octenyl succinic anhydride, and the formed amphiphilic molecule formed micelles with a diameter of 230 nm.…”

“…, bioaccessibility, micellar structures were observed, and the digesta remained active against the proliferation of human CRC cells. 105 Co-encapsulation of curcumin and quercetin in shellac micelles enabled the synergistic antioxidant and cytotoxic properties of the polyphenols, while maintaining the characteristics feasible for colon delivery. 106…”

“…Shellac has distinct polar and non-polar regimes in its molecular structure, and the small dimension of shellac micelles (14 nm) leads to a loading capacity of less than 8%. 105 Whereas, addition of octenyl succinate on curdlan oligosaccharides provides numerous binding sites leading to a loading capacity of over 20% when co-encapsulating curcumin and quercetin. 107 With the relative small dimensions, surfactant micelles are suitable for delivering LBCs in transparent beverages.…”