Assembled alginate/chitosan nanotubes for biological application.

Biodegradable nanotubes were fabricated through the layer-by-layer (LbL) assembly technique of alternate adsorption of alginate (ALG) and chitosan (CHI) onto the inner pores of polycarbonate template with the subsequent removal of the template. The assembled materials present good film formation ability. The thickness of nanotubes wall can be controlled by changing the assembled layers. The assembled tubular structure was verified by the confocal laser scanning microscope (CLSM) using fluorescent-labeled ALG as well as the measurements of scan electron microscope (SEM) and transmission electron microscopy (TEM). Atomic force microscopy (AFM) images confirm the biodegradable feature of the assembled nanotubes as they are immersed in the pancreatin. Confocal microscopy images show that the assembled ALG/CHI nanotubes can be internalized into the cancer cell readily. The cell viability experiment proves the low cytotoxicity of ALG/CHI nanotubes. The final assembled nanotubes have presented good biodegradability and low cytotoxicity.