Table 2.

In vitro effect (EC₅₀) of ZA-SPNs and soluble ZA on the Vδ2-mediated cytotoxicity of CRC cells and spheroids.

	SW620		HCT-15		HT-29
Compound	Adh a	Sph b	Adh	Sph	Adh	Sph
ZA-SPNs	8 × 10−2	>6 × 10−1	1 × 10−1	5 × 10−1	1 × 10−1	5 × 10−1
ZA	1.2	1.0	1.0	1.1	1.7	1.0

^a The indicated CRC cell lines were cultured adherent to plates and used as targets (Adh). ^b CRC cell lines were used as spheroid targets (Sph) in ultra-low attachment plates. The EC₅₀ value is expressed as the micromolar concentration needed to reach 50% of the maximal cytotoxic effect evaluated calculating the percentage of non-living cells. Results are the average of three determinations with a standard deviation of <10%.