Methods for reducing size and polydispersity index of polymeric vesicles – effect of magnetic stirring speed, time, and centrifugation

We report a facile protocol to produce uniform poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-b-PCL) polymeric vesicles (PVs), via film hydration method. Several physical attributes of nanostructures determine their safety, stability, efficacy, as well as their in vitro and in vivo behavior. These include average particle size/diameter and polydispersity index (PDI), which is an indication of their quality with respect to the size distribution (Danaei et al., 2018). In this sense, aiming to reduce the size and PDI values we investigated three parameters: magnetic stirring speed (rpm), time (h), and centrifugation (xg), according to the Figure 1. The PVs obtained presented diameters and PDI of 220 nm and 0.200, respectively. According to our results, the best method is to employ the highest magnetic stirring speed (900 rpm) by 48 h, and recover the PVs in the supernatant after centrifugation for 15 min.