Porcine pancreatic lipase (PPL) has been immobilized in the mesoporous channels of SBA-15 possessing different pore diameters. The nano-sized channels entrapping enzymes could be considered as nanoreactors due to the narrow pore-size distribution and one-dimensional channels of the host

and the internal diffusion and kinetics in the enzymatic hydrolysis have been investigated. The dependence of the Thiele modulus and the internal effectiveness factors on the pore size

as well as the correlation of kinetic parameters with the internal diffusion

indicate that

in the range of pore size <9.4 nm

the internal diffusion limitation significantly occurred

when pore size was larger than 10.9 nm

the internal diffusion limitation made less impact on the enzymatic reaction.