Page 59 - IJB-1-1

Edgar Y. S. Tan and Wai Yee Yeong

the use of a new multi-nozzle printing approach to http://dx.doi.org/10.1111/j.1365-2982.2011.01843.x.
achieve in-process cross-linking. Hydrogel tubular 6. Ramakrishna S, Fujihara K, Teo W-E, et al. 2006, Elec-
structures of large diameter with good shape fidelity trospun nanofibers: Solving global issues. Materials
and integrity were demonstrated. Limitation of this Today, vol.9(3): 40–50.
method includes shrinkage induced during the cross- http://dx.doi.org/10.1016/S1369-7021(06)71389-X.
linking process, which require further optimization of 7. Chung S, Ingle N P, Montero G A, et al. 2010, Biore-
sorbable elastomeric vascular tissue engineering scaf-
the process. We also demonstrated the capability of folds via melt spinning and electrospinning. Acta Bio-
this fabrication technique with a tall hydrogel tubular materialia, vol.6(6): 1958–1967.
structure of at least 15 mm in length in the vertical http://dx.doi.org/10.1016/j.actbio.2009.12.007.
configuration. There is potential to further develop 8. Cui L, Zhang N, Cui W, et al. 2015, A novel na-
this concentric printing method to create a branching no/micro-fibrous scaffold by melt-spinning method for
tubular tree structure with further fine-tuning of the bone tissue engineering. Journal of Bionic Engineering,
tool path design. vol.12(1): 117–128.
This paper also proposed quantifiable parameters http://dx.doi.org/10.1016/S1672-6529(14)60106-2.
for printing quality which could help in characterizing 9. An J, Chua C K, Leong K, et al. 2012, Solvent-free fa-
new materials for bioprinting in terms of shape fidelity. brication of three dimensionally aligned polycaprolac-
We proposed that shape fidelity can be quantified as tone microfibers for engineering of anisotropic tissues.
Biomedical Microdevices, vol.14(5): 863–872.
tubular length, wall thickness and roundness. Printing http://dx.doi.org/10.1007/s10544-012-9666-3.
effects such as spreading and opaque layer thickness 10. Harding S, Afoke A, Brown R, et al. 2002, Engineering
(cross-linking layer thickness) were also proposed. and cell attachment properties of human fibronec-
The definition of these parameters would be crucial in tin–fibrinogen scaffolds for use in tissue engineered
developing systematic studies in research as we move blood vessels. Bioprocess and Biosystems Engineering,
closer towards developing printing of new organs and vol.25(1): 53–59.
tissues. http://dx.doi.org/10.1007/s004490100268.
11. Motlagh D, Yang J, Lui K Y, et al. 2006, Hemocompa-
Conflict of Interest and Funding tibility evaluation of poly (glycerol-sebacate) in vitro
for vascular tissue engineering. Biomaterials, vol.27(24):
No conflict of interest was reported by the authors. 4315–4324.
This work has been funded by NTU Start-Up Grant http://dx.doi.org/10.1016/j.biomaterials.2006.04.010.
(SUG). 12. Stamm C, Khosravi A, Grabow N, et al. 2006, Bioma-
trix/polymer composite material for heart valve tissue
References engineering. The Annals of Thoracic Surgery, vol.78(6):
2084–2093.
1. Zorlutuna P, Hasirci N and Hasirci V, 2008, Nanopat- http://dx.doi.org/10.1016/j.athoracsur.2004.03.106.
terned collagen tubes for vascular tissue engineering. 13. Jeong W, Kim J, Kim S, et al. 2004, Hydrodynamic mi-
Journal of Tissue Engineering and Regenerative Medi- crofabrication via "on the fly" photopolymerization of
cine, vol.2(6): 373–377. microscale fibers and tubes. Lab on a Chip, vol.4(6):
http://dx.doi.org/10.1002/term.99. 576–580.
2. Hasan A, Memic A, Annabi N, et al. 2014, Electrospun http://dx.doi.org/10.1039/B411249K.
scaffolds for tissue engineering of vascular grafts. Acta 14. Sun Z, Zussman E, Yarin A L, et al. 2003, Compound
Biomaterialia, vol.10(1): 11–25. core–shell polymer nanofibers by co-electrospinning.
http://dx.doi.org/10.1016/j.actbio.2013.08.022. Advanced Materials, vol.15(22): 1929–1932.
3. Seifu D G, Purnama A, Mequanint K, et al. 2013, http://dx.doi.org/10.1002/adma.200305136.
Small-diameter vascular tissue engineering. Nature Re- 15. Suntornnond R, An J, Yeong W Y, et al. 2015, Biode-
views Cardiology, vol.10(7): 410–421. gradable polymeric films and membranes processing
http://dx.doi.org/10.1038/nrcardio.2013.77. and forming for tissue engineering. Macromolecular
4. Penkala R A and Kim S S, 2007, Gastrointestinal tissue Materials and Engineering.
engineering. Expert Review of Medical Devices, http://dx.doi.org/10.1002/mame.201500028.
vol.4(1): 65–72. 16. Yang F, Williams C G, Wang D-A, et al. 2005, The ef-
http://dx.doi.org/10.1586/17434440.4.1.65. fect of incorporating RGD adhesive peptide in polye-
5. Bitar K N and Raghavan S, 2012, Intestinal tissue en- thylene glycol diacrylate hydrogel on osteogenesis of
gineering: Current concepts and future vision of rege- bone marrow stromal cells. Biomaterials, vol.26(30):
nerative medicine in the gut. Neurogastroenterology 5991–5998.
and Motility, vol.24(1): 7–19. http://dx.doi.org/10.1016/j.biomaterials.2005.03.018.
International Journal of Bioprinting (2015)–Volume 1, Issue 1 55