Tailoring uptake and release of ATP by dendritic glycopolymer/PNIPAAm hydrogel hybrids: first approaches towards multicompartment release systems

A multicompartment release system is described which combines the advantages of dendritic architectures and hydrogels to enhance the desired delivery features in complex biological compartments. Here, a hydrogel hosts dendritic glycopolymers as nanocontainers and a delivery system for drug molecules. The dendritic glycopolymer used consists of a hyperbranched poly(ethylene imine) with a maltose shell and acts as a host for the guest molecule adenosine triphosphate disodium salt hydrate (ATP). The ATP uptake and release from the dendritic host have been elucidated in detail with dependence on the dendritic glycostructure and pH. The complex interactions within the three components ATP, dendritic glycopolymer and hydrogel have been evaluated and could be fine-tuned. A selective release at pH 5.4-7.4 only of ATP from the multicompartment release system ATP@dendritic glycopolymer@hydrogel has been achieved when a boronic acid containing hydrogel was used which allowed chemical binding between the maltose units from the dendritic glycopolymer and the boronic acid (BA) units in the hydrogel. However, when using a hydrogel without BA units, simultaneous release of ATP and the dendritic glycopolymer scaffold from the ATP@dendritic glycopolymer@hydrogel multicompartment release system is observed in the pH range 2-7.4. This multicompartment release system can be applied in complex biological environments with changing pH values and has potential in biomedical applications and sensory devices.