Surface-engineered encapsulation of probiotic bacteria for protection and functionalization

Probiotic bacteria can stimulate health and can work synergistically with antibiotics to eradicate intestinal infections. However, after oral administration along their way through gastric-intestinal tract, probiotic bacteria need protection against gastric acids and the antibiotics they need to collaborate with. Accordingly, biomaterial encapsulation of probiotic bacteria against antibiotics is a rapidly emerging field. Compared with genetic engineering, which bears the risk of creating a “super-bug” resistant to all antimicrobial measures known, biomaterial encapsulation is a much safer method and offers controllable protection which can be stopped on demand. In this thesis, various passive biomaterial encapsulations are evaluated. In addition, a protective biomaterial encapsulation based on silica nanoparticles combined with bacterially-derived carbon quantum dots has been developed that assist the probiotic bacteria in performing their beneficiary function for the host. This new, active encapsulation method may constitute a first step towards the development of a non-living replacement of probiotic bacteria.