A short review on chemical properties, stability and nano-technological advances for curcumin delivery

Fabrication of curcumin-zein-ethyl cellulose composite nanoparticles using antisolvent co-precipitation method

The stable colloidal nano-dispersion of curcumin (CU) loaded zein-ethyl cellulose (ZN-EC) as three hydrophobic agent in water was prepared using two step antisolvent co-precipitation method. The EC coated NPs were prepared by adding EC in ethyl acetate to the ZN-CU NPs at a concentration ratio of 1: 3.5 w/v. The prepared colloidal suspension of ZN-EC showed high physical stability during storage time. The particle diameters and zeta potential values of ZN-CU and ZN-CU-EC colloidal suspensions were 140 ± 12 nm, 38 ± 2 mV and 179 ± 12 nm, 12 ± 2 mV, respectively. Based on Scanning electron microscopy (SEM) images, participation of EC on the surface of ZN-CU particles could reduce the sticky appearance of particles. Encapsulation efficiency of CU in NPs did not improve after precipitation of EC, but the stability of NPs against pH changes, increased and release rate of CU from NPs at different pH values (3-8) were significantly reduced in comparison of ZN-CU NPs. The EC coated NPs showed the excessive protection for CU antioxidant activity during storage. In conclusion, the prepared NPs, with high physical stability, have good potential for encapsulation and delivery of CU to colon region.

Development of curcumin-loaded composite phospholipid ethosomes for enhanced skin permeability and vesicle stability

Ethosomes are widely applied as the carriers for the transdermal delivery of hydrophobic and hydrophilic drugs. Herein, curcumin-loaded ethosomes (CE) with different phospholipid composition were formulated and thoroughly compared. A significant interaction between the unsaturated phosphatidylcholine (PC) and saturated hydrogenated phosphatidylcholine (HPC) was found by molecular simulation and differential scanning calorimetry (DSC), which led to the reduction of PC peroxidation with the presence of HPC. Subsequently, the composite phospholipid ethosomes containing curcumin were prepared for the first time to evaluate their properties in comparison with the conventional ethosomes composed of PC (CE-P) or HPC (CE-H). CE with PC/HPC ratio of 1:1 (CE-P1H1) with the best vesicle stability and flexibility significantly decreased the uptake by HaCaT cells compared to CE-H and free curcumin, indicating reduced skin cell toxicity. Compared with free curcumin, CE-P1H1 had the highest transdermal efficiency (p < 0.001), followed by CE-P (p < 0.05), partly due to the fact that CE-P1H1 could disturb lipid domain of stratum corneum (SC). Moreover, CE-P1H1 was found to promote curcumin for deep penetration of the skin via the hair follicles route. Our study has shown that using composite phospholipid ethosomes as lipid vesicular carriers could enhance transdermal penetration of drugs and increase in the vesicle stability.

Curcumin encapsulated colloidal amphiphilic block co-polymeric nanocapsules: colloidal nanocapsules enhance photodynamic and anticancer activities of curcumin

Curcumin-based novel colloidal nanocapsules were prepared from amphiphilic poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (F108). These colloidal nanocapsules appeared as spherical particles with size ranging between 270 and 310 nm. Curcumin fluorescence spectra exhibited an aggregation-induced 23 nm red-shift of the emission maximum in addition to the enhancement of the fluorescence quantum yield in these nanocapsules. The cytotoxicity of curcumin and colloidal nanocapsules was assessed using human derived immortalized cell lines (A549 and A375 cells) in the presence and absence of light irradiation. The nanocapsules exhibited a >30-fold decrease in IC₅₀, suggesting enhanced anticancer activity associated with curcumin encapsulation. Higher toxicity was also reported in the presence of light irradiation (as shown by the IC₅₀ data), indicating their potential for future application in photodynamic therapy. Finally, A375 cells treated with curcumin and the nanocapsules showed a significant increase in single- and/or double-strand DNA breaks upon exposure to light, indicating promising biological effects.