Mesoporous Materials in Drug Delivery

As discussed formerly, pore size is very determinative in adsorption of drug molecules inside the mesoporous structure. The size of porosity can be changed in a broad range (2-50 nm) with altering the chain length of polymeric micelles which make the mesostructured appropriate for delivery of different size of bioactive molecules concluding small drug molecules and large proteins [7]. The size of pores is determinant not only on adsorption of diverse drug molecules but also on the rate of release [8]. Vallet-Regi and co-workers [9] synthesized two silica mesoporous structure (MCM-41 and SBA-15) with different surface area in application as a vehicle for alendronate as drug model in which the one with higher surface yielded to more loading efficacy. Some efforts have been done to have a controlled release of drug such as surface functionalization with chemical groups resulted in strong bindings with drug molecules and a controlled rate in release [10]. As illustrated by Song and co-workers [11], functionalization of MCM-41 and SBA-15 with amino groups was a very operative method in controlling the release rate of ibuprofen. In this research, the ionic binding between carboxyl groups of ibuprofen and amino groups of functionalized surface of mesopores has a very effective impact on controlled release. Another method in controlling the rate of release is functionalization of surface with hydrophobic groups. Some researchers [12] functionalized the surface of SBA-15 with hydrophobic groups like octyl and octadecyl resulted in declining the pore size and hydrophilicity of the surface, the parameters which are so effective in controlling the release rate of erythromycin as a drug model.