Synthesis of chitosan nanocomposites for controlled release applications.

Chitosan (CS) was modified using hydroxyapatite (HA) and multiwalled carbon nanotubes (MWCNT) followed by crosslinking with glutaraldehyde (GA). The obtained products were characterized and investigated with thermal analysis. The modified CS suffered a slight weight loss % up to 240 °C then extensive weight loss (EWL)% up to 420 °C and a slight weight loss again until the end of measurement at 700 °C. The treatment showed more thermal stability of modified CS over the blank CS. The 20% HA modified CS showed the highest thermal stability among CS/HA composites while adding CNT to the matrix in CS/HA/CNT composites enhances their thermal stability. Ability of the modified CS to uptake metal ions was investigated by using Cu(NO3)2 where CS/HA/CNT/GA showed higher metal ion uptake than CS/HA/GA. Modified CS was preliminary checked for controlled release of 5-fluorouracil (FU), as an antitumor model drug, in aqueous media where the maximum release of FU was obtained after 48 h. This is concluding the ease of release of FU from the investigated matrices which can be arranged in the order of P111F > P121F > P211F > P311F > P221F > P321F.