Fig. 1.

DT-liposome association in formulations prepared in CB or PB. The liposome-associated DT and free DT were separated through SEC fractionation of formulations by their corresponding buffers and determined with Lowry-Peterson protein assay (a) and ELISA (b); free DT in PB and CB served as control. DT liposome formulations prepared in CB and PB were eluted in SEC with PBS (referred to as “eluted by PBS,” c and d). The resulted liposome-associated DT fractions were further treated with 1% Triton X-100 to release the encapsulated DT, and both were measured with ELISA (referred to as “treated by Triton X-100”). Data are shown as mean + SD of three different batches.