The aim of this work was to synthesize cationic dendrimer with a thermoresponsive polymer tail and complex the dendrimer with negatively charged apoferritin protein nanocage. These kind of systems are developed, for example, for biomedical applications.
Spermine dendron with atom transfer radical polymerization initiator in focal point was synthesized successfully. Thermoresponsive poly(di(ethylene glycol) methyl ether methacrylate) was in situ polymerized to the dendron to form the thermoresponsive dendrimer. All products were characterized with 1H NMR. Cloud point of the final product was determined with DLS, and it was shown to be between 25 and 35 °C.
Complexation of dendrimer and apoferritin was observed with DLS, SAXS and TEM. Complexation was not temperature dependent but complexes had slight thermoresponsive characteristics. Size and zeta potential of the complexes were dendrimer concentration dependent. In defined salt concentration apoferritin and dendrimer formed also crystallline structures.
To improve thermoresponsive properties of the dendrimer and especially of the complexes, further development should be done in the polymerization of the dendron since longer polymer tail could improve thermoresponsiveness. Also other dendrimer generations, dendrimers and protein cages could be tested to enhance electrostatic interactions between the protein cage and the dendrimer.
