Cu (II)-coordinated silica based mesoporous inorganic-organic hybrid material: synthesis, characterization and evaluation for drug delivery, antibacterial, antioxidant and anticancer activities

A Schiff's base supported Cu (II)-metalated Inorganic-Organic hybrid material was synthesized using mesoporous silica MCM-41 as an inorganic support. (3-aminopropyl) triethoxysilane and 2-hydroxy-1-naphthaldehyde were utilized for Schiff's base formation. The hybrid was characterized by FT-IR, Small angle powder-XRD, N2 adsorption-desorption isotherm, Field emission scanning electron microscopy (FE-SEM), Dynamic light scattering (DLS), Thermogravimetric analysis, EDX, Inductively coupled plasma atomic emission spectroscopy (ICP-AES), DRUV-Vis and EPR techniques, to support its formation. The potential of Cu (II)-hybrid was investigated as drug carrier by performing in-vitro pH-responsive drug release experiments, using curcumin as drug molecules. Release percentage of drug was 72% at pH 5.0 (mimicking the tumor environment) and 12% at pH 7.4 (mimicking the extra-cellular surroundings in normal cell) after 24 h. Further, this curcumin loaded Cu (II)-hybrid (HyCu-Cur) was studied for antibacterial and antioxidant activities. The results showed that HyCu-Cur was active against both the bacterial strains; and antioxidant assay showed DPPH-radical scavenging capability was 82% at 1.0 mg/ml HyCu-Cur. Also, the cytotoxicity of Cu (II)-hybrid and HyCu-Cur was also examined by performing MTT assay against normal and cancer cell lines. The materials exhibited toxicity to the cancer cells without affecting normal cells to good extent, thereby showing their non-toxic nature.