Table 2. Studies reporting biomaterial moduli of constructs cultured over time.

Studies marked in green, yellow and red demonstrated that the moduli of cell-laden biomaterial constructs increased, remained constant, or decreased, respectively, throughout the specified culture duration. Coloured arrows indicate changes in the outputs for the IVD cell delivery biomaterial system over culture time. ↑, ↔ or ↓ indicate that the resultant biological or biomechanical output measured increased, remained the same, or decreased, throughout culture. G′, G″ and G* values are reported at 1 Hz.

study	Macromer	Additional crosslinker	Additional modifications	Culture duration	Primary biological findings	Culture	Primary biomechanical findings
Chou et al., 2009	Alg [2 %]	Irradiation (Irgacure 2959) [0.05 %]	NA	4 weeks	↑ Proteoglycan synthesis	8 weeks	↑ Ey: ~1.3 – 4.3 kPa (~200 %)
Foss et al., 2014	Alg [0.5 – 4 %]	NA	Other (GCSN & CS) [125 – 500 & 100 – 400 mg/mL]	4 weeks	↑ Cell viability and proliferation ↑ Col II synthesis ↓ GAG and water content	4 weeks	↑ HA: ~0.2 – 1.4 MPa (~100 %)
Reza et al., 2010a	Cel [1 – 5 %]	Irradiation (Irgacure 2959) [0.05 %]	NA	1 week 2 weeks	↑ Cell viability ↑ ECM synthesis	2 weeks	→ Ey: ~2 – 5 kPa (N.S. change)
Reza et al., 2010b	Cel [2.5 %]	Irradiation (Irgacure 2959) [0.05 %]	NA	4 weeks	↑ DNA content ↑ ECM synthesis	4 weeks	→ Ey: ~5 – 20 kPa (D0 N.R.)
Gupta et al., 2011	Cel [2 %]	Irradiation (Irgacure 2959) [0.05 %]	NA	3 weeks	↑ Proliferation ↑ Col II, CS and GAG synthesis	3 weeks	↑ Ey: ~1 – 2 kPa (~25 %)
Gupta et al., 2014	Cel [1.75 %]	Irradiation (Irgacure 2959) [0.05 %]	NA	8 weeks	↑ ECM synthesis	8 weeks	↑ Ey: ~2 – 30 kPa (~900 %)
Varma et al., 2018	Cel [2 %]	APS/TEMED [10 mM & 10 mM]	NA	5 weeks	↑ Cell viability ↑ ECM synthesis	5 weeks	↑ Ey: ~5 – 30 kPa (~500 %)
Silva-Correia et al., 2013	GG [2 % w/v]	Irradiation (Methyl benzoylformate) [0.1 % w/v]	NA	3 weeks	↑ Cell viability	3 weeks	↑ G′: ~60 – 120 kPa (~50 %)
Kim et al., 2015	HA [1 % w/v]	Irradiation (Irgacure 2959) [0.5 % w/v]	NA	8 weeks	↑ Cell viability ↑ NP-specific gene expression ↑ ECM synthesis	8 weeks	↑ Ey: ~2 – 160 kPa (~8000 %) ↑ G*: ~1 – 2 MPa (D0 N.R.)
Kumar et al., 2014	Ac [13.5 % w/v]	Irradiation (Irgacure 2959) [0.5 % w/v]	NA	2 weeks	↑ Cell viability and proliferation ↑ ECM synthesis	2 weeks	↔ Ey: ~2.5 – 4.5 kPa (N.S. change)
Barreto-Henriksson et al., 2019	Pep [1 %]	NA	NA	3 weeks	↑ GAG synthesis	4 weeks	↑ G′: ~82 – 138 kPa (~70 %) ↑ G″: ~16 – 25 kPa (~55 %)
Wan et al., 2016	Pep [25 – 35 mg/mL]	NA	NA	2 weeks	↑ Cell viability ↑ ECM synthesis	2 weeks	↓ G′: ~5 – 20 kPa (~75 %) ↔ G″: ~1 – 3 kPa (N.S change)
Mercuri et al., 2013	Decellularised porcine NP matrix	Carbodiimide (EDC/NHS & PGG) [30 mmol/L/6 mmol/L & 0.15 %]	NA	2 weeks	↑ Cell viability ↑ ECM synthesis	2 weeks	↑ G*: ~4 – 20 kPa (~100 %)