Page 228 - IJB-9-5

International Journal of Bioprinting Hydrogels for 3D bioprinting

Figure 6. The images of nanoparticles. SEM showing (A) the topography (A1, A2) and the printed grid structure (A3) of HA at low and high magnification.
Reproduced with permission [122] . (B) GO-np particles and GO-np loaded in the hydrogel (B1, B2) and printed grid structure (B3). Reproduced with
permission [123] . TEM showing (C) nanocellulose (NCB) before (C1) and after crosslinking (C2) and printed human ear shape (C3). Reproduced
with permission . (D) Gold nanorods (GNRs) and the cross-sectional pore structure of the GNRs and the scaffold in the hydrogel. Reproduced with
[28]
permission [124] .

the scaffold. The CH/PVA/HA (15 wt%)/BMP-2 scaffold polymer materials can change its mechanical and
shows good biocompatibility and promotes the attachment rheological properties. Laponite nanoparticles are used as
and proliferation of human MSCs [102] (Figure 6A). a physical crosslinking agent, which is an ideal crosslinking
Hydroxyapatite is an extensive additive component of bone method. Reacting with hydrogels will not produce toxic
grafts, and the scaffold mixed with hydrogel for printing by-products [104] .
is a promising treatment method in the field of bone
tissue engineering. Laponite silicate clay, as filler in the SA and MC
hydrogels, has shown good experimental results in 3D
4.1.3. Laponite (clay) bioprinting and drug delivery. Ahlfeld et al. used squeeze
Among the scaffold materials used in bone and cartilage printing to achieve the high fidelity of the printing bracket
tissue engineering, nano-Laponite is one of the most and improve the printability of the hydrogel . Human
[21]
promising materials due to its excellent biocompatibility, mesenchymal stem cells (hTert-MSCs) encapsulated in
biodegradability, and non-toxic degradation products. hydrogels showed high cell viability after 21 days of culture.
Because its surface has positive and negative charges, it Besides, bovine serum albumin and vascular endothelial
can form gels with other materials through electrostatic growth factor (VEGF), which is an angiogenesis-related
interactions, meeting the shear-thinning properties of growth factor, are two model proteins. The sustained
bioinks in bioprinting, with larger specific surface areas release phenomenon of loading in hydrogel proves the
and lower production costs [21,103] . Laponite is nanosized biological function advantage of Laponite in hydrogel .
[21]
lithium–magnesium–sodium silicate of the smectite group, As we mentioned earlier, the core of successfully printing
which is a synthetic material. Mixing with biofriendly hydrogels into a 3D structure is the viscosity of the

Volume 9 Issue 5 (2023) 220 https://doi.org/10.18063/ijb.759