Fig. 9. Colony forming units (CFU) of E. coli bacteria after treatment with TMPyP-loaded hydrogels depending on (a) release time (illumination time fixed to 36 min) and (b) illumination time (release time fixed to 90 min) (the intergroup differences between the samples and the dark control were statistically significant (P < 0.05) for all illumination durations equal to or greater than 4 min (two-tailed t-test; n ≥ 3)) (* refers to values that are zero).