3D Nanostructures for Tissue Engineering, Cancer Therapy, and Gene Delivery

Figure 16

DNA encapsulation and gene transition. (a) Double-walled nanotubes of carbon, which encapsulate ssDNA. (i) A transmission image of ssDNA molecules composed of 30-base cytosine homopolymers (defined as C30) encapsulated double-walled carbon nanotubes by an electron microscope (TEM). (ii) Layout TEM image structure and (iii) simulation of TEM image. (b) A single-walled carbon nanotube encapsulated with ssDNA. TEM photographs, after soaking, of a solution ssDNA (i) without CaCl₂ and (ii) CaCl₂ (DNA-CaCl₂). The ssDNA internalization happened at (iii). (c) Multiwalled carbon nanotubes which are used for strong plasmid DNA encapsulation. The cells in HeLa were treated with DNA-multiwalled carbon plasmid nanotubes during the encapsulation process. Box magnifications for each cell are given (ii and iii). (iv) A multiwalled carbon nanotube which separates the cell membrane. White dotted arrow: chromatin; white dotted arrow: mitochondria; white dotted arrow: atomic membrane; white arrow: vacuole. To: ssDNA [118].