Page 170 - IJB-10-3

International Journal of Bioprinting 3D bone: Current & future

Table 5. Continued...
Type of Material Benefits Drawbacks Crosslinking 3D printing
material mechanism technique
Hydrogel Chitosan 63 Good biocompatibility; good Fast degradation; poor mechanical Ionic crosslinking; Extrusion; DLP;
cell adhesion; osteogenic properties; high cost photo-crosslinking; laser-assisted
potential self-assembly
Collagen Good biocompatibility; Fast degradation; poor mechanical Thermal crosslinking Extrusion; inkjet;
biodegradable; low properties; low viscosity; slow laser-assisted
immunogenicity; good cell gelation; inconsistent 3D structure;
adhesion; regulates cell poor 3D shape maintenance
differentiation
Hyaluronic acid 64 Good biocompatibility; good Low mechanical strength; high Chemical Extrusion;
viscoelastic properties; highly cost crosslinking; laser-assisted
hydrophilic; anti-microbial enzymatic
crosslinking; thermal
crosslinking; ionic
crosslinking; photo-
crosslinking
Decellularized Good bioactivity; native-like Poor mechanical properties; low Thermal crosslinking Extrusion;
ECM 66-69 tissue microenvironment; viscosity; fast degradation laser-assisted;
high maintenance of growth electrospun
and differentiation factors
Cellulose Already approved for Some derivatives could elicit Chemical Extrusion
biomedical applications; immune responses or cytotoxic crosslinking;
good bioprintability effects; highly hydrophilic; limited enzymatic
osteoconductivity crosslinking
Additional Hydroxyapatite Supports bone formation; Complicated to use with ionically Does not undergo Extrusion;
non-organic improves mechanical cross-linked hydrogels; mesh size crosslinking as laser-assisted
materials properties, osteoconductivity, must be controlled; tends to be polymers
and bioactivity quite rigid and brittle; prone to
cracking or fracturing
Biphasic calcium Supports bone May elicit an inflammatory Biphasic calcium Extrusion
phosphate formation; improves response when implanted; phosphate does not
(BCP) 95-98 mechanical properties bioprinting is challenging; undergo crosslinking
and biodegradability; has mechanical strength limitations as polymers
controlled degradation
Calcium Naturally biodegradable; Infrequently employed in Calcium carbonate Extrusion
carbonate can act as a buffer; facilitates bone bioprinting; limited does not undergo
ECM deposition osteoconductivity; weak crosslinking as
mechanical strength; poor polymers
biocompatibility
Abbreviations: DLP: Digital light processing; ECM: Extracellular matrix; PEGDA: Polyethylene glycol diacrylate; SLA: Stereolithography;
UV: Ultraviolet.
main inorganic components of the ECM are calcium and and simultaneously enhance the mechanical properties
phosphorus, both of which are essential for bone formation. of hydrogels. The different inorganic components are
Bone tissues also contain calcium, magnesium, fluorine, discussed as follows:
sodium, and sulfate ions in crystalline form. Hence, these (i) HA: HA is the naturally occurring mineral form of
materials should be provided to the culture medium or calcium apatite. It accounts for up to half the volume
scaffold materials for cells to effectively build the tissues of and more than two-thirds the weight of a human
the artificial bone. Calcium phosphate bioceramics, such as bone. Its components are 39.68% calcium and
synthetic HA, tricalcium phosphates (TCPs), and biphasic 18% phosphorus by weight and hydroxyl groups.
calcium phosphate, provide calcium and phosphorus. Synthetic HA has a relatively similar composition
Likewise, the other trace elements and silicon that support and crystallography as natural HA and is used for
bone formation are provided by bioactive glass. These bone tissue engineering (e.g., bone and teeth repair
particles retain the biological properties of the constructs filler). 3D bioprinting has made it possible to develop

Volume 10 Issue 3 (2024) 162 doi: 10.36922/ijb.2056