This award supports theoretical and computational research and education to advance understanding of biomaterials, which are an increasingly important and expanding class of novel materials. Synthetic polymers, large molecules made of many repeating molecular units, are commonly used in biomaterials. The main requirements of the polymers are biocompatibility, often biodegradability and resistance to proteins. For many polymers these properties correlate with the level of hydration, the presence of bound water molecules around the polymers, which is a common feature shared by biocompatible synthetic polymers and large molecules produced by living organisms. Understanding the hydration of polymers is important for developing new biomaterials and optimizing their performance. The PI will investigate the mechanism of polymer hydration and the factors influencing its level. Through advanced computer modeling that includes processes across many scales of length and time combined with theoretical analysis, the research will contribute to the fundamental understanding of the geometrical structure of polymers and hydration in curved layers, which are commonly encountered in assemblies of nanoparticles and polymers that are used in biomedical applications. The presence of water inside the soft nanoparticles will have a strong impact on drug encapsulation, stability and release, as well as the rate of biodegradation of the nanoparticle, which is important for the development of drug-delivery carriers. The research will yield experimentally testable predictions and guidance for future experimental academic and industrial research. The project will contribute to the technological development of new biomaterials, which can make important contributions to biomedical nanotechnology. Education and training of graduate and undergraduate students as well as a postdoctoral researcher is an important part of the project, which contributes to training a diverse next generation workforce in the area of modern materials modeling and simulation, and analytical methods to enable future technological advances in the design and manufacture of new materials.
This award supports theoretical and computational research and education to advance understanding of biomaterials. Macromolecular hydration is one of the important factors determining the behavior and properties of biomacromolecules and most water-soluble polymers. Despite the recognition of the importance of hydration for the bulk behavior of macromolecules, the mechanisms and factors influencing the hydration, especially on surfaces and self-assembled macromolecular structures where accessibility of water is limited, remain unknown so far. This project is aimed to achieve fundamental understanding of hydration of water-soluble biocompatible polymers in curved layers and self-assembled structures by using advanced theoretical and computational tools. Hydration of polymers protecting nanoparticles can have a profound effect on surface-protein interactions or biocompatibility, water penetration to the underlying layer and diffusion of hydrophobic molecules through the protective polymer layer of a surface or nanoparticle. In the first part of the project the research team will investigate using a combination of atomistic and coarse-grained molecular dynamic simulations how surface curvature, grafting density of chains, polymer length and temperature affect conformation and hydration of polyethylene oxide chains grafted to gold surfaces and nanoparticles. In the second part of the project using a combination of different simulation techniques the research team will systematically study a series of polymer micelles with polyethylene oxide as corona block and different core blocks and analyze the role of the chemical nature and length of core block as well as the temperature on micelle structure, extent of hydrogen bonding as well as water and polymer distribution throughout the micelle. Based on the obtained computer modeling results a simplified simulation approach and analytical model accounting for polymer-water hydrogen bonding in competition with water-water hydrogen bonding will be developed. The implication of the obtained results for important biomaterial applications, such as drug encapsulation will be investigated as well. This project will contribute to the fundamental understanding of the biomaterial properties that are essential for their technological development and applications. Results obtained in the project will also contribute to improved understanding of properties and functions of biopolymers where hydration plays an important role. The simulation model and analytical approach that will be developed in the course of the research project will be useful in further academic research and technological developments in a range of areas employing water-soluble polymers. Training of postdoctoral researchers, graduate and undergraduate students in the area of modern simulation methods and bio/nanotechnology will be one of the important outcomes of the project.
