Recently mesoporous silica materials attracted interest as drug carriers due to their advantages, such as tunable pore size and morphology, and dual-functional surface (external and internal). The preparation of appropriate... [ view full abstract ]
Recently mesoporous silica materials attracted interest as drug carriers due to their advantages, such as tunable pore size and morphology, and dual-functional surface (external and internal). The preparation of appropriate drug delivery systems based on these materials can solve some problems associated with low stability and poor bioavailability of bioactive molecules. Curcumin is a natural polyphenol compound with pleiotropic pharmacological activity (anticancer, antiviral, and antioxidant activity) whose exceptionally low aqueous solubility and poor pharmacokinetic properties have hampered its development beyond the preclinical level. A possible approach to overcome these limitations is the encapsulation of curcumin into nano-carriers, incl. mesoporous silica materials.
In the present study we have investigated curcumin loaded initial or NH2-modified mesoporous silicates (KIT-6 and KIL-2).
Fig. 1. Structural formula of curcumin and TEM image of NH2-modified mesopurous silica carrier.
The obtained systems were further modified by surface coating with an oppositely charged couple of polyelectrolytes, i.e. carrageenan and chitosan. KIL-2 and KIT-6 were synthesized and modified by post-synthesis method with amino groups. Curcumin was loaded by incipient wetness impregnation method on the parent and NH2-modified mesoporous supports. The prepared systems were characterized by powder XRD, N2 physisorption, TEM, TG analysis, UV-Vis and ATR- FT-IR and solid state NMR spectroscopies. The formulated NH2 – modified mesoporous silica carriers were caracterized with higher curcumin loading capacity as compared to initial materials. Spectroscopic data suggested the formation of curcumin complexes on the NH2-modified supports. The in vitro release profiles of curcumin from the tested silica carriers were investigated as a function of time at physiological pH. Additionaly, a comperative study of citotoxic potential of free and formulated curcumin was further performed on a panel of human tumor cell lines. The results show that curcumin encapsulated into polymer coated, modified silica carriers proved to exert superior antineoplastic potential as compared to free drug. Thus, it can be concluded that modified silica particles are promising carriers for delivery of curcumin.
Acknowledgements: Financial support from National Science Fund of Bulgaria (grant DH 09/18) is greatly acknowledged.
Targeted drug delivery and nanocarriers , Nanomedicine for cancer diagnosis & therapy
