Conjugation of polybasic dendrimers with neutral grafts: effect on conformation and encapsulation of acidic drugs

We examine the role of neutral dendrimer grafts upon the conformations and the drug complexation efficacy of weakly basic polyelectrolyte dendrimers by using a self-consistent field theory approach. Our results indicate that grafted chains modify the conformations of the dendrimers and lead to a swelling of the dendrimer, the degree of which increases with increasing chain length of the grafts. In turn, such conformational changes leads to a higher charge being carried by the dendrimer molecule. We compare the encapsulation efficacy of grafted and non-grafted dendrimers and find that for strong enough enthalpic and/or electrostatic interactions, the grafted dendrimers are capable of higher amounts of encapsulation than the non-grafted counterparts. By isolating the influences of electrostatic and enthalpic interactions, we clarify the physics behind the observed enhanced encapsulation.