NANOTECHNOLOGY AND 3D BIOPRINTING FOR NEURAL TISSUE REGENERATION - 3D Bioprinting and Nanotechnology in Tissue Engineering and Regenerative Medicine - page 315

FIGURE 14.10
(A1-A2) Schematic illustration of PPy/collagen complex scaffold design and (A3-A4) PC-12 cells culture and
electrical stimulation. (A5) Stimulation waveform. Fluorescence microscopy images of PC-12 cells grew on PPy/
collagen scaffold with high (B1) and low (B2) magnification. Images are adopted from Weng et al. (2012) .
printing ( Ferris et al., 2013 ). The bioink was composed of endotoxin-free low-acyl gellan gum, Milli-Q
water, Dulbecco's Modified Eagles Medium, Poloxamer 188 surfactant, and/or fluorosurfactant solu-
tion mixed with cells. Neural (PC-12) and skeletal muscle (C2C12) cells which contained bioinks can
maintain high cell viability over extended time periods without settling and aggregation.
Time-released delivery systems are another important feature that is highly desirable with regards to
tissue engineered constructs. Growth factors incorporated within tissue substitutes can support and pro-
mote cell adhesion and proliferation during the initial period of implantation when endogenic growth
factors are absent ( Kokai et al., 2011; Lee et al., 2003 ). Lee et al. developed an artificial neural tissue
containing vascular endothelial growth factor (VEGF) release by printing murine neural stem cells