Figure 4.

Retention of lentivirus on PLL-functionalized PEG hydrogels. (A) PEG hydrogels containing 2.5 mM RGD were functionalized with either 30–70 kDa PLL or additional RGD (0.45 mg/mL; n = 4). Virus was incubated with the hydrogels for three hours at 37°C then washed with PBS to remove non-binding virus. Unbound virus in the supernatant was collected and assayed via qPCR at different time points. Following the two washes, no detectable level of virus was found in the PLL-functionalized hydrogels. (B) The fraction of lentivirus released from the hydrogel was calculated by dividing the eluted virus particles by the initial virus loading. Significant differences between corresponding RGD and PLL conditions are denoted by an asterisk (**P ≤ 0.01; ****P ≤ 0.0001).