Assessing Cytotoxicity and Metabolic Activity of HSEs

HSEs were exposed to SAAP-148, lyophilized and redispersed SAAP-148-loaded nanogels or placebo nanogels at the desired concentrations in PBS for 4 h including 1% (v/v) Triton^TM X-100 as positive control and PBS as negative control. Afterwards, LDH release from dead cells to the basal medium was detected by the Cytotoxicity Detection Kit according to manufacturer’s instructions. Furthermore, the HSEs were cut out, transferred to 24-well flat-bottom culture plates, and exposed to WST-1 reagent in DMEM medium overnight to determine the metabolic activity of the cells in the models. Read-out of medium solutions without the HSEs was performed according to manufacturer’s protocol. Results are expressed as percentage cytotoxicity or metabolic activity relative to controls.