Multifunctional Protocells for Enhanced Penetration in 3D Extracellular Tumoral Matrices

The high density of the extracellular matrix in solid tumors is an important obstacle to nanocarriers for reaching deep tumor regions and has severely limited the efficacy of administrated nanotherapeutics. The use of proteolytic enzymes prior to nanoparticle administration or directly attached to the nanocarrier surface has been proposed to enhance their penetration, but the low in vivo stability of these macromolecules compromises their efficacy and strongly limits their application. Herein, we have designed a multifunctional nanocarrier able to transport cytotoxic drugs to deep areas of solid tumors and once there, to be engulfed by tumoral cells causing their destruction. This system is based on mesoporous silica nanocarriers encapsulated within supported lipid bilayers (SLBs). The SLB avoids premature release of the housed drug while providing high colloidal stability and an easy to functionalize surface. The tumor penetration property is provided by attachment of engineered polymeric nanocapsules th...