A comparative study of enzyme initiators for crosslinking phenol-functionalized hydrogels for cell encapsulation

Biomaterials Research

Table 1 Physical properties of PVA-Tyr hudrogels crosslinked via varying enzyme types and concentrations

Enzyme			Oxidant			Time to gel (min)^a	Final absorbance at gelation (325 nm)^b	Sol fraction (% mass loss at 48 h)	Swelling (q, at 48 h)	Crosslinking density (ρ_x, mmol/L)^c	Dynamic shear modulus (G*, Pa)
Name	Concentration	Unit	Name	Concentration	Unit	Time to gel (min)^a	Final absorbance at gelation (325 nm)^b	Sol fraction (% mass loss at 48 h)	Swelling (q, at 48 h)	Crosslinking density (ρ_x, mmol/L)^c	Dynamic shear modulus (G*, Pa)
HRP	0.1	U/mL	H₂O₂	6	mM	20	1.4 ± 0.2	32 ± 7 %	29 ± 3	2.2	138 ± 43
	0.2			6		15	2.0 ± 0.2	31 ± 5 %	23 ± 1	3.8	219 ± 30
	0.2			12		20	1.2 ± 0.1	36 ± 7 %	33 ± 5	1.6	89 ± 24
Hematin	0.01	% (w/w)	H₂O₂	6	mM	60	0.3 ± 0.0	76 ± 8 %	168 ± 36	0.1	5 ± 1
	0.06			6		15	0.7 ± 0.2	63 ± 10 %	121 ± 25	0.1	11 ± 3
	0.06			12		30	1.1 ± 0.1	49 ± 11 %	84 ± 16	0.2	38 ± 5
Laccase	5	U/mL	O₂			360+	2.4 ± 0.2	33 ± 6 %	26 ± 4	2.8	97 ± 34
Laccase	15	U/mL	O₂			240	2.9 ± 0.1	24 ± 10 %	21 ± 3	4.6	145 ± 22
Tyrosinase	500	U/mL	O₂			150	1.7 ± 0.1	26 ± 5 %	44 ± 7	0.9	145 ± 49
Tyrosinase	750	U/mL	O₂			150	2.0 ± 0.2	20 ± 8 %	35 ± 10	1.4	169 ± 56

^aGelation time was determined as the time when there was no further significant increase in absorbance
^bThe absorbance after the hydrogel had completed gelation as determined by the time to gel
^cCrosslinking density was determined from swelling (q) at 48 h using equations derived from Flory and Rehner [30]

ISSN: 2055-7124