Table 2. Average TGFβ percent cumulative release and retention over 3 days.

Polyelectrolyte multilayers (PEMs) of chitosan and heparin (terminal layer) were created on tissue culture polystyrene (TCPS). Then, transforming growth factor β (TGFβ) or fibronectin (FN, 100 μg/mL) or both were adsorbed on the PEMs as shown in Figure 1. TGFβ was quantified in the supernatant to determine potential release following adsorption to the heparin-terminated PEMs. Estimates are given when ELISA response of samples was below the lower limit of detection. ‘N.D.’ indicates that TGFβ concentration could not be determined in the supernatant, suggesting that the majority of the TGFβ was still retained on the heparin-terminated PEMs.

			% Cumulative TGFβ release			% Cumulative TGFβ retention
TGFβ (pg/ml)	FN	Average TGFβ mass bound to PEMs (pg)	D0 (2 h)	D1	D3	D0 (2 h)	D1	D3
10,000	−	545.2	9.8	11.4	11.4 - 13.2	90.2	88.6	86.8 - 88.6
1000	−	42.7	15.1	15.1 – 22.6	N.D.	84.9	77.4 – 84.9	N.D.
100	−	1.8 – 5.2	N.D.	N.D.	N.D.	N.D.	N.D.	N.D.
10,000	+	542.3	13.4	15.7	15.7 – 17.5	86.6	84.3	82.5 – 84.3
1000	+	42.9	21.5	29.5	29.5 – 52.6	78.5	70.5	47.4 – 70.5
100	+	1.8 – 5.2	N.D.	N.D.	N.D.	N.D.	N.D.	N.D.