Hélder Santos, Harvard University, Cambridge, MA, USA, and colleagues have developed a procedure for the fast production of core/shell nanocomposites in large quantities of up to 700 g per day on a single microfluidic device. The device consists of three sequential nested glass capillary tubes. The innermost tube contains a solvent in which the core precursor precipitates, the second tube contains a solution of the precursors for the core and for the shell, and the outermost and last tube contains a solvent in which both the core and shell precursors precipitate. The device sequentially mixes the three solutions. The core material, e.g., a drug, precipitates first and is then immediately encapsulated in the shell, e.g., a polymer. The process operates in a continuous way.
The researchers demonstrated their method by successfully encapsulating either of the anticancer drugs paclitaxel or sorafenib in a shell of the polymer hypromellose acetate succinate. The obtained materials showed a narrow size distribution and a high drug loading. The team emphasizes that the method does not require any additional stabilizers for the core and is easily scalable to produce industrially relevant quantities.