Our strategy uses temperature changes as a simple and fast organic solvent-free nanogel formation method to encapsulate biomolecules. Poly(N-cyclopropylacrylamide) (PNCPAM), closely related to PNIPAM, consists of pendant cyclopropylamine groups instead of the isopropylamine groups in PNIPAM and possesses a LCST of ~49 °C. We propose herein that the copolymerisation of NCPAM and NIPAM to form block copolymers together with a hydrophilic block -consisting of a short block with functional reactive handles and polyethylene glycol (PEG) -provides an efficient method to precisely control the LCST, and hence the self-assembly temperature, from 32 up to 49 °C. Fine-tuning of the transition temperature using a library of copolymers, with precise control of the LCST around body temperature, enables application-dependent selection of a certain copolymer from the library to create customised vehicles for loading and release of sensitive therapeutic protein cargoes.