Silica-deposited phospholipid nanotubules as a plausible drug targeting system

Abstract

An aqueous dispersion of self-organized phospholipid tubules has been utilized as the template for silica-deposited nanotubules (∼0.5 μm thick and >10 μm long) by a sol–gel method. The formation of the hybrid tubules was mechanistically investigated by controlled sol–gel reaction. The incorporation of silica increases the mechanical and thermal stability of tubule geometry. After bioconjugating Ni²⁺-nitrilotriacetic acid (Ni-NTA) to the surface of chemically modified tubules containing primary amine groups, green fluorescent protein (GFP)-6 His and A33scFv-6 His were further bioconjugated in order to investigate a potential application of these hollow silica tubules as vehicle for targeted controlled release. The resulting tubules bound and internalized to SW1222 endothelial human colon carcinoma cells that express the A33 cell-surface glycoprotein more specifically than HT29 cells that do not express this antigen.

Keywords::

• Biomineralization
• phospholipid
• nanotubules
• self-assembly
• silica
• carcinoma cells

Acknowledgements

I.K. thanks the National Core Research Center Program from MOST and KOSEF (R15-2006-022-01001-0), the Center for Ultramicrochemical Process Systems (CUPS) and Brain Korea 21 Program for financial supports. The support of the Ludwig Institute for Cancer Research is also recognized. I.K. also thanks Dr Soazig Delamarre for helping cell culture experiments.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.