Evaluation of L929 cell and blood toxicity of DOX-loaded SELP nanogels. (a) L929 fibroblast viability curves in response to increasing DOX concentration of DOX alone, DOX-loaded SELP 815K, and DOX-loaded SELP 815K-RS2. (b) L929 fibroblast viability in response to increasing SELP concentration at concentrations mimicking DOX-loaded SELP samples. (c) Percent hemolysis of human blood erythrocytes following 3 hr incubation with various samples. (d) Concentration of iC3b found in human plasma following incubation with various samples, as determined by complement EIA. Data plotted as mean ± standard deviation; n = 3. *, p < 0.05 from PBS control; ***, p < 0.001 from PBS control.