title: A Smart pH-responsive Nano-Carrier as a Drug Delivery System: A hybrid system comprised of mesoporous nanosilica MCM-41 (as a nano-container) & a pH-sensitive polymer (as smart reversible gatekeepers): Preparation, characterization and in vitro release studies of an anti-cancer drug.
abstract: A smart pH-responsive drug nano-carrier for controlled release of anti-cancer therapeutics was developed through a facile route. The nano-carrier consisted of two main parts: first, the nano-container part (that mesoporous silica nanoparticles (MCM-41) were selected for this aim); and second, pH-sensitive gatekeepers (that a pH-sensitive polymer, Poly4-vinylpyridine, played this role). In the first step, MCM-41 was synthesized via template assisted sol-gel process. In the second step, polymerizable functional groups were attached onto pore entrances rather than inside walls. In the third step, polymeric gatekeepers were introduced onto pore entrances via precipitation polymerization of functionalized MCM-41 with monomers. Different methods and analysis, such as Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Powder Diffraction (XRD), Thermo-Gravimetric Analysis (TGA), Energy-Dispersive X-ray Spectroscopy (EDX), Zeta Potentials, Dynamic Light Scattering (DLS), Field Emission Scanning Electron Microscope (FE-SEM) and Transmission Electron Microscopy (TEM) were employed to approve the successful attachment of gatekeepers. Furthermore, the release studies of methotroxate (MTX), an anti-cancer drug, were performed in different media (pH4, 5.8 and 7.4) at 37±1°C. The release profiles and curves show that the release rates are completely pH-dependent and it proceeds with a decrease in pH. It is concluded that in the higher pH the gatekeepers are in their close state, but they switch to the open state as a consequence of repulsive forces between positively charged polymer chains appear in acidic media. The results suggest that this smart nano-carrier can be considered as an appropriate candidate to deliver therapeutics to cancerous tissues.
authors: Chemistry Department, Faculty of Science, Azarbaijan Shahid Madani University, Tabriz, Iran. Electronic address: Abdrahimabaszad@yahoo.com.
authors: Abdolrahim
authors: A
authors: Abbaszad Rafi
authors: Chemistry Department, Faculty of Science, Azarbaijan Shahid Madani University, Tabriz, Iran.
authors: Mehrdad
authors: M
authors: Mahkam
authors: Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Soodabeh
authors: S
authors: Davaran
authors: Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Hamed
authors: H
authors: Hamishehkar
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage*; D004337:Drug Carriers; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008854:Microscopy, Electron; D053758:Nanoparticles; D011108:Polymers / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D000970:Antineoplastic Agents; D004337:Drug Carriers; D011108:Polymers; D012822:Silicon Dioxide
keywords: Anti-cancer drugs; Drug delivery systems; MCM-41; Sol-gel process; pH-sensitive nano-carriers