In vitro determination of PHACOS and PHO cytotoxicity and immunocompatibility. (a) Determination of PHO cytotoxic effect on mouse RAW 264.7 macrophages by MTT assay. Negative control extracts were incubated with PET disks. Positive control cells were treated with LPS to monitor the decrease in cell viability. (b) Determination of PHACOS cytotoxic effect on RAW 264.7 macrophages. (c) Determination of PHO and PHACOS cytotoxic effect on mouse fibroblasts (BALB 3T3). Control extracts were incubated with PET disks. (d) Griess test. Inflammatory activity of PHACOS and PHO on RAW 264.7 macrophages measured as increase of NO production, Open, light gray, dark gray, and black bars represent, respectively, positive control (cells treated with LPS), negative control (extracts incubated with PET), incubated with PHACOS, incubated with PHO.