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3D bioprinting for tissue engineering: Stem cells in hydrogels
gical demand for bespoke solutions. Author Contributions
Material compatibility with such advanced systems
must also be assessed. A physiologically relevant sca- All authors contributed towards the writing of this
ffold must be able to support and guide cell growth review paper. We thank Dr. James Bowen for his in-
and differentiation both chemically and physically. As sights and discussions.
well as creating complex blends of bioinks, this would Conflict of Interest and Funding
require heterogeneous material fabrication and preci-
sion-printing to create organized gradients or complex No conflict of interest was reported by all authors.
patterns of cells and functional motifs which mimic This work was supported by the Medical Research
native ECM more closely. One approach currently Council (MR/K026453/1, MAB and NM) and the En-
being explored to meet these requirements is the use gineering and Physical Sciences Research Council
of smart materials, i.e., materials that are able to (EP/K504610/1, GZT).
change their shape, mechanical strength and permea- References
bility in response to external or physiological stimu-
li [117] . Smart hydrogels can respond to changes in 1. Hull C W, 1986, Apparatus for production of three-di-
pH [122] , temperature [123] and electric and magnetic mensional objects by stereolithography. US 4575330 A,
fields [124,125] . These materials are particularly attractive Google Patents.
as the scaffold could mould itself as the cells mature. http://dx.doi.org/10.1007/s11427-015-4850-3
An alternative approach is to print decellularised 2. Leigh S J, Bradley R J, Purssell C P, et al., 2012, A sim-
ECM directly to provide the structural and chemical ple, low-cost conductive composite material for 3D
cues the cells require. It is believed by some research- printing of electronic sensors. PLoS ONE, vol.7: e49365.
ers that no matter how complex the hydrogel-based 3. http://dx.doi.org/10.1371/journal.pone.0049365
Berman B, 2012, 3-D printing: The new industrial revo-
scaffolds become, decellularised ECM is still the lution. Business Horizons, vol.55(2): 155–162.
closest representation of an in vivo environment [126] http://dx.doi.org/10.1016/j.bushor.2011.11.003
and therefore the future of bioprinting tissues. The 4. Rengier F, Mehndiratta A, von Tengg-Kobligk H, et al.,
downside with this method is harvesting the ECM first 2010, 3D printing based on imaging data: Review of
but if tissue-specific ECM can be derived with ease, medical applications. International Journal of Computer
then this method may help resolve some of the cell Assisted Radiology and Surgery, vol.5(4): 335–341.
functionality issues currently experienced when using http://dx.doi.org/10.1007/s11548-010-0476-x
other, more conventional scaffolds. 5. Mehrban N, Bowen J, Vorndran E, et al., 2013, Struc-
Through the various examples cited in this review, tural changes to resorbable calcium phosphate bioce-
it is clear that bioprinting itself has been successfully ramic aged in vitro. Colloids and Surfaces B: Biointer-
used to maintain cell viability and incorporate cell- faces, vol.111: 469–478.
http://dx.doi.org/10.1016/j.colsurfb.2013.06.020
guiding cues into complex scaffold materials. The main 6. Mehrban N, Paxton J Z, Bowen J, et al., 2011, Compar-
challenge facing researchers in this field today is ing physichochemical properties of printed and hand
fine-tuning the technique to mirror native tissue com- cast biocements designed for ligament replacement.
plexity. The goal in tissue engineering is always to Advances in Applied Ceramics, vol.110(3): 162–167.
improve the patient’s quality of life and by creating http://dx.doi.org/10.1179/1743676110Y.0000000012
bespoke materials that are able to regenerate or guide 7. Ricci J L, Clark E A, Murriky A, et al., 2012, Three-
tissue development in a cheap and fast way, 3D bio- dimensional printing of bone repair and replacement
printing has become a powerful and highly flexible materials: Impact on craniofacial surgery. Journal of
tool for achieving this. Furthermore, as knowledge on Craniofacial Surgery, vol.23(1): 304–308.
technologies and materials advances, it is entirely http://dx.doi.org/10.1097/SCS.0b013e318241dc6e
plausible that in the future in situ bioprinting systems 8. Tsang V L and Bhatia S N, 2004, Three-dimensional
tissue fabrication. Advanced Drug Delivery Reviews,
could be developed to both scan the patient’s wound vol.56(11): 1635–1647.
site and print the cell-laden scaffold directly into the http://dx.doi.org/10.1016/j.addr.2004.05.001
wound, all without leaving the operating theatre. Sig- 9. Mironov V, Boland T, Trusk T, et al. 2003, Organ print-
nificant progress in this area has already been made ing: Computer-aided jet-based 3D tissue engineering.
towards skin [21] and cartilage repair [22] . Trends in Biotechnology, vol.21(4): 157–161.
14 International Journal of Bioprinting (2016)–Volume 2, Issue 1

