Interactions of bioactive molecules with thin dendritic glycopolymer layers

Area of Science:

• Materials Science
• Polymer Chemistry
• Biotechnology

Background:

• Dendritic glycopolymers offer unique structural properties for advanced material applications.
• Developing biocompatible surfaces for drug delivery remains a key challenge in nanomedicine.

Purpose of the Study:

• To synthesize and characterize highly swellable dendritic glycopolymer layers on SiO(x) substrates.
• To investigate the drug loading and release capabilities of these glycopolymer layers.
• To evaluate the influence of cross-linking agents on swelling, drug complexation, and biomolecule adsorption.

Main Methods:

• Synthesis of dendritic glycopolymers with hyperbranched poly(ethylene imine) cores and maltose shells.
• Cross-linking of glycopolymer layers using poly(ethylene-alt-maleic anhydride) (PEMA) or citric acid on SiO(x) substrates.
• Analysis of swelling and biomolecule adsorption using spectroscopic ellipsometry and quartz crystal microbalance with dissipation.
• Confirmation of drug complexation via X-ray photoelectron spectroscopy.

Main Results:

• PEMA-cross-linked glycopolymer layers exhibited up to 10 times higher swelling and adenosine triphosphate (ATP) complexation compared to citric acid-cross-linked layers.
• ATP complexation was confirmed to occur via electrostatic interactions with the poly(ethylene imine) cores.
• Complexation induced layer collapsing, stiffening, and increased viscosity, with ATP binding primarily at the layer-solution interface.
• The PEMA-cross-linked layers demonstrated resistance to adsorption of larger biomolecules like vitamin B12 and human serum albumin (HSA) due to diffusion barriers.

Conclusions:

• Dendritic glycopolymer layers cross-linked with PEMA show superior swelling and drug complexation properties.
• These materials present a promising platform for developing biocompatible surfaces for targeted drug loading and controlled release.
• The observed resistance to larger biomolecule adsorption suggests potential for selective drug delivery applications.