The MCM-41-based nanocomposite was synthesized via in situ co-polymerization of functionalized MCM-41 (polymerizable MCM-41) with methacrylic acid (MMA). To prepare nanocapsules, the synthesized nanocomposite was treated with hydrofluoric acid (HF) and as a result the MCM-41 was removed. These pH-sensitive materials were characterized by FT-IR, EDX and SEM, also their structure and the role that MCM-41 plays were investigated. Naproxen, as a model drug, was entrapped into these drug carriers and the in vitro release profiles were established separately in both enzyme-free simulated gastric (SGF, pH 1) and simulated colonic fluids (SCF, pH 7.4). The release rates at SCF were higher than that of SGF. In addition, study shows that the silanol groups of MCM-41 play a role in drug entrapment efficiency.