Synthesis of functional polymers within a protein cage for encapsulation and delivery of biomacromolecules and the development of composite hybrid membranes for water evaporation applications

Abstract

In this thesis two projects were conducted that had the incorporation of synthetic polymers in common albeit at different scales, the nano and the macro scale. In the nanoscale project functional polymers were synthesized from initiators bound to the interior of a protein cage, the thermosome. The thermosome has pores that are large enough for biomacromolecules like nucleic acids or proteins to enter and leave the cavity. The synthesized cationic polymers within the thermosome acted as anchors through electrostatic interaction and prevented anionic macromolecules from diffusing out of the cage. Delivery experiments of biomacromolecules into mammalian cells were conducted with the thermosome-polymer conjugates. SiRNA and fluorescent proteins were delivered into cells and the results highlight the potential of the conjugates for therapeutic drug delivery. Moreover, the entrapped molecules were protected from degradation by the local biological environment and the cage structure of the thermosome shielded cells from positive charges, which are otherwise cytotoxic. In the macroscale project a thin water vapor permeable membrane was equipped with synthetic polymers forming amphiphilic conetworks. The thin climate membranes are widely used in apparel or medical applications. Their drawback is that when punctured, they cannot close this puncture autonomously. Therefore, the thin membrane was equipped with an amphiphilic conetwork in order to add self-closing properties while, in addition, being capable to let water vapor pass the membrane. The self-sealing properties increased with the thickness of the amphiphilic conetwork layer. In the two projects, the addition of synthetic polymers allowed generation of new functionalities in nano transporters and they provided improvement of the properties of synthetic membrane.