Despite the increasing successes in discovering protein-based medicines, their manufacture in a cost effective and reliable fashion remains a major industrial challenge, which currently limits the ability of the biopharmaceutical industry to deliver solutions to patients. Crystallisation can potentially offer a paradigm-changing breakthrough for purification in biopharmaceuticals. It is well known that nucleation is a conception stage and governs the entire crystallisation process. The influence of nanoparticle porosity and surface chemistry on heterogeneous nucleation and crystallisation of macromolecules will be presented - for batch and continuous crystallisation (oscillatory flow crystallisers) platforms for small molecule pharmaceutical solids and large complex biopharmaceuticals. The impact of nanoparticle seed properties on the induction times for batch crystallisation and development of a continuous bioseparation platform will be presented. A Template Induced Polymorphic Occurrence Domain (TiPOD) concept on the nucleation of different polymorphic forms, and approaches based on Quartz Crystal Microbalance for surface heterogeneous nucleation will be discussed. For the continuous platform, the impact of amplitude and frequency on crystallisation of a model protein (lysozyme), and a scale-up workflow will be presented. Here, we demonstrate the potential of a continuous protein crystallisation platform for downstream separation. Here, we show how nanoparticles can be designed to control nucleation and develop seeding strategies to realise a continuous biocrystallisation platform.