Characterization of synthesized carboxymethylnanochitosan loaded with streptomycin and testing its in vitro anticancer activity

Abstract

This study aims to synthesize carboxymethylnanochitosn (CMNC) from synthetic nanochitosan (NC) which was produced from chitosan and encapsulated streptomycin(S) then characterized and bioassayed. A quantity of 2 mg of chitosan was selected for nanochitosan synthesis. Maximum absorbance (λmax) was determined for streptomycin (S), CMNC and CMNC-S were 280, 265 and 270 nm, respectively. The loading efficiency of CMNC with S was 90%. Fourier transform-infrared (FTIR) spectroscopy for CMNC and CMNC-S showed that absorption peaks at the same frequencies 3000 -3800 cm^-1 with the change in stretching of the absorption percent, which increased sharply. Scanning electron Microscope (SEM) of chitosan, NC, CMNC and CMNC-S showed aggregation of CMNC and entrapment of S nanoparticles within CMNC. Results of atomic force microscope (AFM) images and analysis illustrated that the concentration 2mg/ 100 ml of soluble chitosan recorded a diameter 54.64 nm and the insoluble chitosan at the same concentration resulted in 105.52 nm. According to the process of CMNC preparation, the nanoparticles size achieved 35 nm. After loading CMNC with S, the average of the nanoparticles increased to 37 nm. Results confirmed the loading process of CMNC with S. Particle size distribution showed median particle size of CMNC recording 770 nm and for CMNC-S was 526 nm. The concentration 50µg/ml of CMNC-S reached 37.5% growth inhibition (GI%) against rhabdomyosarcoma (RD) cell line in comparison with 38.5% GI  for streptomycin (100µg/ml) after 24 hrs of incubation.