Polyaminoacid nanocapsules for drug delivery to the lymphatic system: Effect of the particle size

Previous work by our group showed the possibility to reduce the toxicity of docetaxel upon its encapsulation in polyaminoacid nanocapsules with a size of 200 nm. The objective of this study was to elucidate whether a reduction in the nanocapsules size might facilitate their access to the lymphatic system. To do so, we analyzed the effect of several formulation parameters on the characteristics of polyglutamic acid, PEGylated polyglutamic acid and polyasparagine nanocapsules. From these experiments, we could identify the best conditions to produce nanocapsules with a small size (close to 100 nm) and adequate capacity to encapsulate and sustain the release of the antitumor drug docetaxel. Moreover, the results of the stability study made evident the critical role of the polyaminoacid shell on the colloidal stability of the nanocapsules in biologically relevant media. Finally, we studied the influence of the particle size (100 nm vs. 200 nm) on the biodistribution of PGA-PEG nanocapsules following subcutaneous injection. The results showed that the 100 nm-size nanocapsules accumulate faster in the lymph nodes, than those with a size of 200 nm. In summary, these data suggest the potential of 100 nm-size polyaminoacid nanocapsules as lymphatic drug delivery carriers. (C) 2016 Elsevier B.V. All rights reserved.