Production of polycaprolactone nanoparticles with hydrodynamic diameters below 100 nm

Cancer is a worldwide increasing burden and its therapy is often challenging and causes severe side effects in healthy tissue. If drugs are loaded into nanoparticles, side effects can be reduced, and efficiency can be increased via the enhanced permeability and retention effect. This effect is based on the fact that nanoparticles with sizes from 10 to 200 nm can accumulate in tumor tissue due to their leaky vasculature. In this work, we produced polycaprolactone (PCL) in the sizes 1.8, 5.4, and 13.6 kDa and were able to produce spherical shaped nanoparticles with mean diameters of 64 ± 19 nm out of the PCL_5.4 and 45 ± 8 nm out of the PCL_13.6 reproducibly. By encapsulation of paclitaxel the diameter of that nanoparticles did not increase, and we were able to encapsulate 73 ± 7 fmol paclitaxel per 1000 particles in the PCL_5.4‐nanoparticles and 35 ± 8 fmol PTX per 1000 PCL_13.6‐nanoparticles. Furthermore, we coupled the aptamer S15 to preformed PCL_5.4‐nanoparticles resulting in particles with a hydrodynamic diameter of 153 nm. This offers the opportunity to use these nanoparticles for targeted drug delivery.