Our ability to precisely manipulate size, shape and composition of nanoscale carriers is essential for controlling their in-vivo transport, bio-distribution and drug release mechanism. Shape-specific, "smart" nanoparticles that deliver drugs or imaging agents to target tissues primarily in response to disease-specific or physiological signals could significantly improve therapeutic care of complex diseases. Current methods in nanoparticle synthesis do not allow such simultaneous control over particle size, shape and environmentally-triggered drug release, especially at the sub 100 nm range. We report here a high-throughput nanofabrication technique using synthetic and biological macromers (peptides) to produce highly monodisperse, enzymatically-triggered nanoparticles of precise sizes and shapes. Particles as small as 50 nm were fabricated on silicon wafers and harvested directly into aqueous buffers using a biocompatible, one-step release technique. We further demonstrate successful encapsulation and precisely controlled enzyme-triggered release of antibodies and nucleic acids from these nanoparticles, thus providing a potential means for disease-controlled delivery of biomolecules.