Improvement of cellular uptake of hydrophilic molecule, calcein, formulated by liposome

The aim of this study was to prepare the liposome with 1,2-distearoyl-sn-glycero-3-phosphocholine, 1.2 dioleoyl-sn-glycero-3-phosphoethanolamine, cholesteyl hemisuccinate, calcein as a drug model and evaluate physicochemical characteristics such as particle size, polydispersity index (PDI), encapsulation efficiency (EE). Also, the morphology of the blank liposome (without calcein) and the calcein-loaded liposome was observed by a transmission electron microscope (TEM). The particle size and PDI of the blank liposome and the calcein-loaded liposome without tween 80 were 139.8 ± 4.497, 0.31 ± 0.03 and 150.8 ± 8.45, 0.29 ± 0.03 nm, respectively. In addition, it was confirmed that the particle size of the calcein-loaded liposome increased from 294. 6 ± 17.8 to 466.4 ± 78.4 nm when tween 80 was used from 1 to 6%. EE of the calcein-loaded liposome was 66.0 ± 0.58%, independent of the concentration of tween 80. TEM images showed that the shape of the blank liposome and the calcein-loaded liposome was round. In vitro drug release test, calcein from the liposome released approximately 20–25 and 40–50% in pH 7.4 and 4.0, respectively, with a sustained release pattern. The cellular uptake of calcein from the calcein-loaded liposome was about 1.08-fold than that from the calcein solution at 10 µM for a 2 h incubation time. These results suggest that the calcein-loaded liposome was successfully prepared, and could be an application for a hydrophilic drug in further study.