TEM at cryogenic temperatures (cryo-TEM) and small-angle neutron scattering (SANS) are two complementary methods to study these types of nanostructures in their native hydrated state. A third technique, fluorescence correlation spectroscopy (FCS) is a diffusion-based single-molecule analysis technique. FCS allows accurate characterisation of nanoparticle assembly/disassembly -including in the presence of enzymatic triggerssurface functionalisation, cargo loading, and release. Our thoroughly characterised nanogel system is shown to serve as a versatile protein delivery platform with a simple and gentle temperature induced formation and loading protocol, and triggered release through stimuli-responsiveness provided by enzymatically cleavable cross-links. This modular platform can be adjusted for disease-specific applications by choosing the appropriate copolymer, peptide cross-linker sequence, and therapeutic protein cargo.