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Atra Malayeri, Colin Sherborne, Thomas Paterson, et al.

cryosectioned PolyHIPE disk demonstrate the integra- micro-scale porosities. This demonstrates control of
tion and penetration of MG63 cells within the micro- porosity at different structural levels. Osteosarcoma
porosity nature of PolyHIPE materials (50 μm depth). cells (MG63) were grown on both the woodpile struc-
These results can be compared to our previous results ture and porous disks of the materials. Cell ingrowth
of human Embryonic Stem Cell derived Progenitors (50 µm in 7 days) was observed in the PolyHIPE disks,
(hESMPs) on similar scaffolds which highlighted that while the woodpile structures supported the growth of
only plasma treated scaffolds supported hESMP cells tumour spheroids, a growth mode that was not ob-
growth [24] . Additionally, the scaffolds supported diffe- served on the disks or on tissue culture plastic. The
rentiation towards osteoblasts in a 14-day timescale, excellent biocompatibility of the parent material was
and this was dependent on the stiffness of the scaffold. not adversely affected by processing to form a com-
Evidence of cell ingrowth can be observed on the plex 3D shape. In addition to preparing in vitro mod-
immunofluorescence images of the woodpile struc- els, this technology when combined with biodegrada-
tures; the cells are very well attached and they pene- ble materials, shows significant potential for the man-
trate within the scaffold (Figure 4B). Interestingly, as ufacture of functional scaffolds or devices for the re-
shown in Figure 4D–E, spherical clusters of MG63 pair of complex tissue defects, as the direct laser writ-
cells were formed within the macropores of the wood- ing may be applied to the fabrication of custom-
pile structures (each spheroid reaching a diameter of shaped porous structures.
approximately 200 μm after 7 days). This growth be-
havior has not been observed on either tissue culture Conflict of Interest and Funding
plastic or the PolyHIPE disk and closely resembles No conflict of interest was reported by the authors.
tumour-like spheroids. This observation indicates that
the HIPE-based macroporous 3D environment encou- Acknowledgments
rages the osteosarcoma cell line to behave in a more
natural way, forming tumour-like spheroids without the This work was supported by the UK Engineering and
requirement of any external manipulation. Previous Physical Sciences Research Council with a PhD stu-
studies have also shown similar findings where MG63 dentship (EP/L014823/1) and by MeDe Innovation
spheroids have been developed (i) in ex vivo bone (the EPSRC Centre for Innovative Manufacturing in
formation models and (ii) in in vitro 3D culture sys- Medical Devices, grant number EP/K029592/1). Im-
tems, for example, using silicate-based hydrogels [29–31] ; aging work was performed at the Kroto Research In-
but the observation of culturing tumour-spheroids in a stitute Confocal Imaging Facility, using the LSM510
3D in vitro structured scaffold has to our knowledge Meta upright confocal microscope.
not yet been reported. Overall, the development of References
PolyHIPE-based 3D scaffolds offers more realistic
opportunities for replicating in vivo behavior of cell 1. Bokhari M, Carnachan R J, Przyborski S A, et al., 2007,
environments. Therefore, this 3D PolyHIPE scaffold Emulsion-templated porous polymers as scaffolds for
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for tumour-on-chip devices. meters on scaffold formation and homogeneity. Journal
of Materials Chemistry, vol.17(38): 4088–4094.
4. Conclusion http://dx.doi.org/10.1039/B707499A
2. Kimmins S D and Cameron N R, 2011, Functional por-
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material was structured in a three dimensional wood- http://dx.doi.org/10.1002/adfm.201001330
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rent microporosity of the PolyHIPE and with a macro- prepared with oil-phase soluble porogenic solvents: span
structure that mimics the structure of cortical bone 80 as surfactant. Macromolecules, vol.37(9): 3188–3201.
(80% porosity and 450 µm pores). Scanning electron http://dx.doi.org/10.1021/ma0359436
microscopy demonstrated that PolyHIPE woodpile 4. Kimmins S D, Wyman P and Cameron N R, 2012, Pho-
structures fabricated via laser-based solid freeform fa- topolymerised methacrylate-based emulsion-templated
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