TABLE 2.

Various functionalisation strategies for PolyHIPE scaffolds from the literature.

Approach	Monomer/macromer	Improvement	Results	References
Chemical functionalisation/Incorporation of functional monomers	Styrene, divinylbenzene, and 2-ethylhexyl acrylate	Incorporation of the monomer acrylic acid into the water phase of w/o emulsion	7.5% carboxylic acid functionality, Increased wettability, No adverse effect on cell attachment	Hayward et al., 2013b
Chemical functionalisation/Post-functionalisation	Poly(styrene/ethylene glycol dimethacrylate)	Air plasma treatment	Increased wettability, Enhanced cell attachment	Pakeyangkoon et al., 2012
	2-Ethylhexyl acrylate and isobornyl acrylate	Air plasma or acrylic acid plasma treatment	Enhanced cell attachment and cellular metabolic activity	Owen et al., 2016
	Polycaprolactone tetramethacrylate	Air plasma treatment	Increased wettability, Enhanced cell infiltration	Aldemir Dikici et al., 2019a
Incorporation of ceramic particles	Styrene	Hydroxyapatite/internal phase	Higher cell viability, penetration and osteoblast differentiation	Akay et al., 2004; Bokhari et al., 2005
	2-Ethylhexyl acrylate and isobornyl acrylate	Hydroxyapatite/internal phase	Improved tensile modulus	Wang et al., 2016
	Thiol-acrylate	Hydroxyapatite and strontium-modified hydroxyapatite/continuous phase	Improved cell adhesion and proliferation	Lee et al., 2017
	Poly fumarate dimethacrylate	Calcium phosphate, hydroxyapatite/demineralised bone matrix	Improved cell attachment andproliferation, Enhanced osteogenicand angiogenic activity	Robinson et al., 2016
Incorporation of biomolecules	Styrene	Peptide coating (Physical)	Improved osteoblast penetration depth and the alkaline phosphatase activity	Bokhari et al., 2005
	Styrene	Poly-D-lysine & laminin coating (Physical)	Poly-D-lysine & laminin coating was found advantageous over only Poly-D-lysine	Hayman et al., 2005
	Thiolene	Fibronectin coating (Physical)	Improved cell attachment, proliferation and infiltration	Eissa et al., 2018
	Thiol-acrylate	Maleimide-derivatised RGD peptide attachment	Improved cell attachment and proliferation	Richardson et al., 2019
	Polycaprolactone tetramethacrylate	In vitro cell-derived extracellular matrix deposition	Improved cell attachment and proliferation, Enhanced osteogenic and angiogenic activity	Aldemir Dikici et al., 2020
Chemical functionalisation/Incorporation of functional monomers + Incorporation of biomolecules	Thiol-acrylate	Functionalisation with sulfo-SANPAH + Covalent fibronectin attachment	Improved cell attachment and infiltration	Richardson et al., 2019
	Styrene	Incorporation of pentafluorophenyl acrylate into the oil phase of the HIPE + Galactose attachment	Higher albumin synthesis by hepatocytes	Hayward et al., 2013a