Calcium carbonate colloidal particles as delivery vehicles to biological systems

Colloidal systems are increasingly being used in consumer products. Special interest is drawn to their application as delivery vehicles. To this end, there is the need of novel synthesis methods to produce colloids with tailored size and morphology in absence of harsh conditions and toxic constituents. One material for such purposes is calcium carbonate, as it can be synthesized in mild conditions besides being endogenous to the body, safe, biodegradable and biocompatible. Yet, there are still limitations that could hinder its use as a viable delivery system, like the morphological and size control, particle instability in aqueous solutions and the sustained release of encapsulated molecules. In this thesis, these aspects are studied in detail and new strategies are explored for the preparation of suitable colloidal carriers with biocompatible cellular interactions. To this purpose, distinct principles that govern biomineralization and complex coacervation are translated to synthetic systems and assessed in vitro by means of monoculture cellular experiments. These principles include: (1) the use of charged proteins and polymers as the assembling components during the complex coacervation; (2) the use of polyelectrolytes molecules to direct the mesoscale assembly of anisotropic nanoparticles; and (3) the study on how the physical and colloidal properties of CaCO3 systems can control particle-cellular interactions. The studies focused on the loading ability, colloidal and crystal phase stability as well as cellular outcome.