Bachelor projects

Incorporation of protein into biopolymer polyelectrolyte complexes.

Student research project (Bachelor thesis or internship)

Incorporation of protein into biopolymer polyelectrolyte complexes.

Within cells, we know that tiny liquid-in-liquid droplets exist called membraneless organelles (MLOs) that among other things help the cell to organize the cell by creating partitioned areas for proteins. We have recently discovered that complexes made from oppositely-charged polyelectrolytes (polymers with charged monomers) have the same properties as MLOs and are able to encapsulate proteins to a very high concentration compared to the surrounding solution. In previous research, we used the synthetic polyelectrolytes (that is to say; polyelectrolytes derived from petrochemical processes) polycationic poly(allylamine) (PAH) and polyanionic poly(acrylic acid) (PAA) as polyelectrolytes and incorporated up to 99.8% of the protein lysozyme into the complexes.

For this project, we would like to change from synthetic polyelectrolytes to naturally-occurring biopolyelectrolytes and see if the same properties for PAH/PAA complexes exist for biopolyelectrolyte complexes. That includes the ability to encapsulate proteins, eject those proteins and to be able to selectively incorporate them. We do not know yet for sure which biopolyelectrolytes to use but candidates are polysaccharides consisting of polymerized sugar rings such as chitosan, alginate or glycogen.

Using biopolymers opens the door to different future applications. First; biopolymers interact more favourably with the environment, so any application based on biopolyelectrolyte complexation would be a lot more environmentally friendly and sustainable. Second, the abilit to encapsulate proteins into complexes is very useful in the field of drug delivery.

Project to-do list;

  • Investigate protein encapsulation into biopolyelectrolyte complexes.
  • Investigate protein ejection from biopolyelectrolyte complexes.
  • Investigate separation of protein mixtures using biopolyelectrolyte complexes.
  • If time allows, investigate the encapsulation behaviour changes under different physiochemical conditions such as temperature, salt concentration and pH of the encapsulation

Department: Nanobiophysics (NBP)

Daily Supervisor: Jéré van Lente,

Project Leader: dr. Saskia Lindhoud,