Self-Assembly of DNA and Cell-Adhesive Proteins onto pH-Sensitive Inorganic Crystals for Precise and Efficient Transgene Delivery

摘要

Intracellular delivery of a functional gene or a gene-silencing DNA or RNA sequence is expected to be a powerfulntool for treating critical human diseases very precisely and effectively. One of the major hurdles to the successful deliverynof a nucleic acid with nanoparticles is the transport across the plasma membrane. The existence of various and numerousncell surface receptors with potential capability of being internalized by cells upon ligand binding unveils the waysnof overcoming the barrier by targeting the nanoparticles to specific receptor. This review will reveal the current progressnon utilizing the cell adhesion molecules as targeting receptors for transgene delivery, with a special focus on the design ofnbio-functionalized inorganic nanocrystals using both naturally occurring and genetically engineered cell adhesive proteinsnfor high efficiency transfection of embryonic stem cells. Self-assembly of both DNA and cell-adhesive proteins, such asnfibronectin and E-cadherin-Fc into the growing nanocrystals of carbonate apatite leads to their high affinity interactionsnwith fibronectin-specific integrins and E-cadherin in embryonic stem cell surface and accelerates transgene delivery fornsubsequent expression. While only apatite nano-particles were very inefficient in transfecting embryonic stem cells, fibronectin-nanchored particles and to a more significant extent, fibronectin and E-cadherin-Fc-associated particles dramaticallynenhanced transgene delivery with a value notably higher than that of commercially available lipofection system. Activationnof protein kinase C (PKC) dramatically enhances transgene expression probably by up-regulating both integrinnand E-cadherin. Thus, the new establishment of a bio-functional hybrid gene-carrier would promote and facilitate developmentnof stem cell-based therapy in regenerative medicine.