Paclitaxel-containing nano-engineered polymeric capsules towards cancer therapy

Paclitaxel is one of the anticancer agents most often used in clinical oncology practice for the treatment of ovarian, breast and non-small cell lung cancers. Nanoengineered polymeric capsules (NPCs) represent a new and very effective tool for the encapsulation and smart release of different compounds. In present work capsules were fabricated by means of the layer-by-layer assembly of oppositely charged polyelectrolytes onto colloidal particles, followed by removal of the cores at low pH to obtain hollow microcapsules. Paclitaxel was loaded into the capsule. As tumors exhibit a lower extracellular pH than normal tissues, the property of NPCs to open the pores in their shell at slightly acidic pH values could be used for the triggered release of paclitaxel within a tumor microenvironment. For the characterization of NPCs, quartz crystal microbalance was used to monitor the process of shell growth on planar supports. The effective encapsulation of paclitaxel was then demonstrated by atomic force microscopy and micro-Raman spectroscopy, whereas its release was characterized by Uv-vis spectroscopy. Finally the biological activity of encapsulated paclitaxel against human breast cancer cells was assessed.