Ph.D. University of Minnesota 2012
In our lab we use polymer chemsitry and engineering to develop new materials for biobased applications.These biomaterials either take the form of hydrogels to mimic the extra cellular matrix or coatings on surfaces that enhance the surface behavior and biological compatibility of the parent material.
Spatiotemporal control over hydrogels
Cells respond to numerous mechanical, topological, and chemical cues from their surroundings (i.e. extracellular matrix) to determine their behavior. Stem cells sense the mechanical and chemical properties of the extracellular matrix (ECM) to help direct their differentiation to adult cell lines and cancer cells sense the mechanics around them to dictate their proliferation. By studying and controlling the properties of the ECM around the cells, researchers can develop new methods to control cell behavior. Hydrogels are an excellent synthetic mimic of the ECM and can be tuned for their desired application. Since cells in the body are structured into tissues with micrometer scale spacing, researchers rely on photopatterning the mechanical properties and molecules of interest in hydrogels to mimic this behavior. However, most of the time the chemistry that dictates the mechanical properties is also used to pattern molecules into the hydrogel and as a result independent patterning of molecules and mechanical properties is difficult. In our lab we work on orthogonal chemistry that allows us to independently pattern mechanical properties and chemicals in hydrogels, providing new systems for temporal and spatial control of properties. Additionally, we work on new hydrogel crosslinking systems that allow for formation of the gel through body tissue.
Whenever a surface exists in nature, micro-organisms (e.g. bacteria) will attach to it. For everyday objects, such bacterial attachment is not an issue, but in systems such as water filtration, implanted medical devices, and the hulls of ships the attachment of organisms such as bacteria can lead to loss of performance and in the case of medical devices, serious medical complications. When possible, frequent cleaning is expensive and coatings that release antibiotics are being phased out due to their ability to generate resistant organisms. Current research aims to use thin coatings of anti-bacterial polymers to kill organisms as they attach to the surface. Unfortunately, these dead organisms provide a barrier to interaction with the anti-bacterial polymers and thus their effectiveness diminishes over time. Our group utilizes block copolymer phase separation to create nanometer scale domains of anti-microbial and anti-adhesion polymers on surfaces to combat the adhesion of bacteria. Furthermore, by using photopatterning we aim to use topography as another tool to combat adhesion to surfaces. With the block copolymer phase separation and photopatterning hierarchical surface structures can be produced.
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- Gramlich, W. M.; Rai, R.; Hollaway, J. L.; Burdick, J. A. Transdermal gelation of methacrylated macomers with near-infrared light and gold nanorods. Nanotechnology, 2014, 25, 014004. Read Abstract
- Gramlich, W.M.; Kim, I.L.; Burdick, J. A. Synthesis and orthogonal photopatterning of hyaluronic acid hydrogels with thiol-norbornene chemistry. Biomaterials, 2013, 34, 9803-9811. Read Abstract
- Morrison, T. X.; Gramlich, W. M. “Tunable, thiol-ene, interpenetrating network hydrogels of norbornene-modified carboxymethyl cellulose and cellulose nanofibrils.” Carbohydrate Polymers 2023, 319, 121173.
- Senkum, H.; Kelly, P. V.; Gramlich, W. M. “Water-Stable Thin-Film Nanostructures from Amphiphilic Cationic Bottlebrush Block Copolymers by Grafting-through Ring-Opening Metathesis Polymerization.” Macromolecules 2021, 54, 7987-7997.
- Dadoo, N.; Zeitler, S.; McGovern, A. D.; Gramlich, W. M. “Waterborne functionalization of cellulose nanofibrils with norbornenes and subsequent thiol-norbornene gelation to create robust hydrogels.” Cellulose 2021, 28, 1339 – 1353.
- Ji, S.; Abaci, A.; Morrison, T.; Gramlich, W. M.; Guvendiren, M. “Novel bioinks from UV-responsive norbornene-functionalized carboxymethyl cellulose macromers.” Bioprinting 2020, 18, e00083
- McOscar, T. V. C.; Gramlich, W. M. “Hydrogels from Norbornene-Functionalized Carboxymethyl Cellulose Using a UV-Initiated Thiol-Ene Click Reaction.” Cellulose 2018, 25, 6531 – 6545
- Dadoo, N.; Landry, S. B.; Bomar, J. D.; Gramlich, W. M. “Synthesis and spatiotemporal modification of biocompatible and stimuli responsive carboxymethyl cellulose hydrogels using thiol-norbornene chemistry.” Macromolecular Bioscience 2017, 17, 1700107.