Fig. 4: Leachability of gel-based implants and in vitro culture of cells on non-leachable injectable elastomers.
a A paper-based test reveals leaching from a commercial silicone gel used in breast implants (Silicone Gel-1) versus non-leaching injectable silicone brush elastomer NCO:OH 1:8. b Time-resolved 1H-NMR of sol extract from the commercial silicone gel and a NCO:OH 1:8 injectable elastomer in D2O monitored over one month (400 MHz): 4.70 (residual H2O), 1.17, 0.01 (leachable materials). c Comparing cytotoxicity of commercial silicone gels and injectable silicone brush elastomers (NCO:OH 1:1→1:8) using NIH/3T3 fibroblasts. Dots in c depict individual samples. Height of the histogram bins and the error bars correspond to mean values ± SD, respectively. For the cytotoxicity test, 104 cells/cm2 cells were examined over 5 independent experiments. d The extracted DNA quantification of cultured NIH/3T3 fibroblasts on injectable elastomers (NCO:OH 1:1→1:8), Sylgard (curing agent to base ratio of 1:10), and tissue culture polystyrene (bars) after 3, 5, 7, and 14 days. The data points and error bars correspond to mean values ± SD. For this test, 5 × 105 cells/ml cells were examined over 5 independent experiments. e Proliferation of NIH/3T3 fibroblasts cultured to the injectable elastomer NCO:OH 1:8 monitored by fluorescence microscopy after 3, 5, 7, and 14 days (actin cytoskeleton and nucleus are displayed in green and blue, respectively). The scale bars correspond to 400 μm. The experiment was conducted on two independent cell lines in parallel showing similar results.
