Exploring Diffusion and Aggregation Behaviors in Carbohydrate Solutions

Engineered glycomaterials represent an exciting new field of biomaterials, owing to their vast structural diversity, yielding a myriad of potential properties and applications. Glycomaterials can be composed of naturally occurring polysaccharides (cellulose, hyaluronic acid, chondroitin sulfate, etc.), but these are also amenable to chemical derivatization, resulting in engineered glycomaterials with altered chemical and material properties. However, rules for predicting the properties of glycomaterials, based on their chemical structure, are not well established, hindering their rational design. Computational methods, such as molecular dynamics (MD) simulation, can accurately characterize the spatial and temporal properties, of glycomaterials; however, the application of MD simulations to predict material properties, such as diffusion, solubility, viscosity, and hydrogel formation, has received less attention. This work demonstrates that diffusion properties of well-known glycomaterial constituents, measured by DOSY NMR spectroscopy and calculated from explicit solvent MD simulations with the GLYCAM06 force field, generally agree well. However, the theoretical results are found to be heavily dependent on the water model, with the TIP5P and OPC models outperforming the widely used TIP3P model. Lastly, an empirical method for estimating the diffusion properties of carbohydrates, based on assessing the number of tightly bound waters, is proposed. Together, these results illustrate the potential of computational approaches to guide the rational design of engineered glycomaterials.