The most striking feature in YPD was the greatly increased viability of the cells for ATRP (>80%), whereas RAFT could only achieve 51% (SI Figure ).Thus, we focused on ATRP in YPD for the ensuing polymerizations. For instance, it was also possible to co-polymerize PEGMA bearing an azide group (PEGMA-N3) (P10), setting the groundwork for surface conjugation.