Figure 2

pH-dependent release of CSA-13 from MNP-CSA-13. CSA-13 release (hydrolysis of imine bond) was monitored by recording changes of surface tension at an air-water interface of a MNP-CSA-13 suspension. A rapid increase of CSA-13 release during the first 10 minutes after placing MNP-CSA-13 in a low pH buffer (pH = 5) was observed (black squares). After this time the shape of the curves indicates further gradual release. On the other hand, at pH = 7.4, slow, but progressive release of CSA-13 molecules from MNP-CSA-13 was observed (white circles). Data represent mean ± SD from 3 experiments.