Layer-By-Layer Synthesis of the pH-Responsive Hollow Microcapsule and Investigation of Its Drug Delivery and Anticancer Properties.

Multilayered pH-responsive hollow microcapsules with non-toxicity and biological specificity advantages were prepared from two kinds of polymers i.e., chitosan (CH) and poly (ethylene glycol dimethacrylate-co-methacrylic acid) (PE) via layer-by-layer (LbL) method, which is followed by subsequent removal of silica core. The hollow nature of obtained spherical microcapsules was found by transmission electron microscopy (TEM). The microcapsules were prepared as gemcitabine (GM) and curcumin (CR) carriers. The drugs have been loaded within the microcapsules during or after the synthetic procedure. Although acceptable loading efficiencies (LE) were obtained in both methods, the amount of drug loaded during the synthesis method is relatively higher. Values above 78% and 87%, for releasing efficiency (RE%) and encapsulation efficiency (EE%), respectively, demonstrate the high potential of the prepared microcapsules for drug delivery. In addition, the difference between the amount of drug released in acidic and neutral pH indicates the pH-responsivity of the prepared microcapsules. Moreover, the dose-dependent high cytotoxicity effect of the prepared microcapsules was observed on the HCT116 colorectal carcinoma cells.