Tunable carbon nanotube/protein core-shell nanoparticles with NIR- and enzymatic-responsive cytotoxicity.

A unique procedure is developed to capture carbon nanotubes into closed virus-like protein cages with a controllable shell. The cross-linked shell varies in thickness within ≈10(0) -10(2) nm, and can be entirely removed by enzyme degradation. The cytotoxicity is entirely suppressed, but can be promoted again by enzymes and near-infrared light. These hybrids can be decorated with functional inorganic nanoparticles or processed into nanocomposites.