. 2018 Jul 17;2(3):036102. doi: 10.1063/1.5022841

TABLE II.

Mechanical characterisation of the fibrin hydrogels produced in this study.

Fibrin conc. (mg/ml)	PEG-peptide (molar ratio)	Oscillatory measures^a		Creep^d
Fibrin conc. (mg/ml)	PEG-peptide (molar ratio)	tan δ^b	G′ (Pa)^c	G (Pa)^e	τ (s)^e	${(J}_{m} {- J}_{0}) / J_{0}$ ^f	η (Pa s)
6.25	…	0.03 ± 0.02^¶	305 ± 203	…	…	…	…
	PEG-pep1 (1:10)	0.02 ± 0.01^¶	256 ± 90	…	…	…	…
	PEG-pep3 (1:20)	0.05 ± 0.04^¶	46 ± 15	…	…	…	…
	PEG-pep2 (1:20)	0.02 ± 0.01^¶	226 ± 52	…	…	…	…
	PEG-pep1 (1:20)	0.03 ± 0.01^¶	119 ± 74	…	…	…	…
12.5	…	0.06 ± 0.01^¶	490 ± 90	420 ± 90	1.8 ± 0.7	0.10 ± 0.02	…
	PEG-pep1 (1:10)	0.05 ± 0.01^¶	540 ± 200	540 ± 100	0.9 ± 0.3	0.01 ± 0.05	…
	PEG-pep3 (1:20)	0.04 ± 0.01	750 ± 300	620 ± 120	1.6 ± 0.3	0.21 ± 0.15	…
	PEG-pep2 (1:20)	0.07 ± 0.01^¶	420 ± 80	360 ± 40	0.4 ± 0.1	0.20 ± 0.04	(5 ± 2) × 10⁴
	PEG-pep1 (1:20)	0.07 ± 0.01^¶	470 ± 60	390 ± 60	0.7 ± 0.1	0.23 ± 0.12	(5 ± 0.1) × 10⁴
25	…	0.05 ± 0.03	1450 ± 280	1240 ± 90	…	…	…
	PEG-pep1 (1:10)	0.05 ± 0.01	1250 ± 200	1050 ± 190	…	…	…
	PEG-pep3 (1:20)	0.05 ± 0.02^¶	1360 ± 460	1080 ± 40	…	…	…
	PEG-pep2 (1:20)	0.07 ± 0.02^¶	1030 ± 90	840 ± 80	1.9 ± 0.02	0.21 ± 0.14	…
	PEG-pep1 (1:20)	0.08 ± 0.03^¶	800 ± 40	690 ± 50	0.7 ± 0.1	0.14 ± 0.02	(12 ± 1) × 10⁴
50	…	0.07 ± 0.04	2860 ± 680	2370 ± 290	…	…	…
	PEG-pep1 (1:1)	0.05 ± 0.02	2460 ± 20	2200 ± 270	…	…	…
	PEG-pep1 (1:10)	0.06 ± 0.02	1470 ± 220	1230 ± 50	…	…	…
	PEG-pep3 (1:20)	0.06 ± 0.02	2100 ± 350	1640 ± 110	…	…	…
	PEG-pep2 (1:20)	0.08 ± 0.03^¶	1260 ± 380	1100 ± 340	2.1 ± 0.2	0.28 ± 0.03	…
	PEG-pep1 (1:20)	0.48 ± 0.17^¶	5 ± 3	4 ± 1	0.4 ± 0.1	0.72 ± 0.27	260 ± 150

^{^a}

Stress: 5 Pa.

^{^b}

Calculated as G″/G′, averaging their values over the 0.01–100 Hz or 0.1–10 Hz frequency range; samples labelled with the ^¶ symbol showed a minor drift of G′ with frequency (n = 3).

^{^c}

Average value at a frequency of 1 Hz (n = 3).

^{^d}

Stress: 5 Pa, duration: 10 min (n = 3).

^{^e}

$G = 1 / J$ was obtained from the modified Standard Linear Solid (SLS) model³⁴ $J (t) = J_{0} + J_{1} + J_{2} = J_{0} + J_{1} (1 - exp (- \frac{t}{τ})) + (\frac{t}{η})$ , which also provided τ and η.

^{^f}

$J_{0}$ represents the purely elastic compliance at the beginning of the creep phase and $J_{m}$ the maximum compliance reached at the end of the creep phase (compliance at 10 min). The parameter ${(J}_{m} {- J}_{0}) / J_{0}$ provides an information all-in-all similar to tan δ (viscoelastic and viscous vs. elastic contributions); when it can be calculated, it appears to be more sensitive than tan δ.