Fiber-based Hydrogels using Flow-induced Gelation Strategies

Princeton University, Princeton NJ

Investigators

Abstract

Hydrogels, which are water-filled polymer networks, are important soft materials with beneficial properties that are currently in demand for tissue engineering, wound healing and various drug delivery applications. There are numerous methods for producing hydrogels, however many of these methods are strongly dependent on chemical composition and or chemical reactions. This award supports the development of a novel family of hydrogel materials produced from long and flexible fibers using a mechanical approach that does not rely on chemical reactions. This phenomenon, where flowing a suspension of microfibers causes the fibers to knot and entangle into a continuous network, is a largely unexplored field but has the potential to contribute significantly to the scientific, engineering, healthcare and industrial communities as it offers a simple and novel alternative route to engineering porous hydrogels with well-controlled properties. This study requires a multidisciplinary effort drawing upon concepts from materials science, flow processing, fluid mechanics, chemistry and bioengineering. The multidisciplinary nature of the research program will provide a rich learning experience for graduate and undergraduate students. The primary research objectives of this project are focused on building a fundamental understanding of the mechanism of gelation of microfibers and the resultant properties of the fiber-based hydrogels when subjected to various flow conditions, thus establishing the structure-property relationships of flow-produced fiber-based hydrogels. These relationships will guide the design and processing parameters for producing fiber-based hydrogels for target applications, such as tissue engineering and surgical adhesives. This research involves both experimental and computational approaches to optimize the design and production of fiber-based hydrogels from flow processing. The experimental component of this project involves microfluidic approaches for fiber synthesis, rheological characterization of fiber suspensions and hydrogels, and imaging analysis of hydrogel microstructure. The computational component focuses on numerical simulation methods to model fiber knotting and entanglements when the suspended fibers are subjected to diverse stress conditions. In addition, the research can contribute meaningful insights to the existing body of literature on the flow properties of suspensions of long and slender objects, which is a very important theme in many industrial processes. Another significant outcome is the development of a unique paradigm for injectable hydrogels that utilizes micron-sized building blocks in a process that is entirely mechanical as the suspension gels in situ during injection without chemical reactions.