Amy Wagoner Johnson

Research Interests

• Women's reproductive health
• Biomechanics
• Biomaterials

Research Statement

Loss of bone through trauma or disease can result in life-threatening complications, so repair of such defects is consequently critical to the health and well-being of patients. Professor Wagoner Johnson's work in biomaterials is laying the scientific groundwork for the design of synthetic bone substitute materials and systems that may one day replace bone grafts currently harvested from patients themselves or from donors. Rejection, disease transmission, and other complications associated with the transplantation of human tissue (as well as the limited availability of donor tissue) make synthetic materials attractive candidates for the repair of bone defects.

To develop such bone substitutes, Professor Wagoner Johnson is investigating how cells and tissues interact with or modify their environment, how tissue grows into the substitute and how drug or stem cell delivery can improve bone in-growth. In one highly collaborative project, her group is investigating scaffolds with pore sizes that span multiple lengthscales, from millimeters to nanometers, as bone replacements for large and load-bearing defects. Researchers in the department's dynamics and controls group make the ceramic (hydroxyapatite) scaffolds via rapid prototype deposition, while researchers in Professor Wagoner Johnson's group work to tailor the scaffold's macro- and microstructure to optimize bone in-growth and mechanical properties of the scaffold/bone composite. As they do so, they work with surgeons from the local hospital, Veterinary Medicine and Animal Sciences to understand and characterize the biological response. The group's preliminary laboratory studies have demonstrated that bone grows more readily into such implants. They believe that tissue infiltrates the microscale pores, which helps to improve mechanical properties of the scaffold in vivo.

The group is also working with researchers at the Indiana School of Medicine on a novel cell-based approach that may make it possible to implant large scaffolds on the order of 10s of centimeters. The size of implants is currently limited by how far the tissues within them are from nutrient-supplying and waste-removing blood vessels. Because living cells cannot survive farther than 150 to 200 microns from a blood supply, cells within large scaffolds typically die before blood vessels from the surrounding tissue can grow into them. By combining two types of stem cells-one from umbilical cord and the other from fat tissue-Professor Wagoner Johnson's group hopes to build blood vessels at the center of the scaffold that can then grow out to connect with vessels outside the scaffold.

Her group also uses a non-destructive imaging technique called Micro-CT, similar to a CAT scan, to understand how bone grows spatially and temporarily into the scaffolds. Such data are used to understand and model the mechanical behavior of the bone/scaffold composites. Students in the group are also developing scaffolds made of a modified form of chitin, the structural material found in the exoskeleton of crustaceans. Gelatin microspheres loaded with a growth factor known to encourage blood vessel growth are built into the scaffolds, which are being developed for the treatment of chronic cutaneous ulcers.

Primary Research Area

• Cell and tissue engineering

Research Areas

• Biomechanics
• Bone and cartilage
• Cell and tissue engineering
• Cellular and molecular biomechanics
• Regenerative tissue engineering
• Scaffolding materials

Selected Articles in Journals

• Woodard, J., A. Hilldore, S. Lan, C. J. Park, A. W. Morgan, J. C. Eurell, S. G. Clark, M. B. Wheeler, R. Jamison, and A. J. Wagoner Johnson, “The Mechanical Properties and Osteoconductivity of Hydroxyapatite Bone Scaffolds with Multi-scale Porosity,” Biomaterials, 28, 45-54, 2007. Listed in the top ten most downloaded June 2007. Cited 456 times as of 6/17 (Google Scholar). As of 2/17, this highly cited paper received enough citations to place it in the top 1% of the academic field of Materials Science based on a highly cited threshold for the field and publication year. Data from Essential Science Indicators℠
• Cordell, J., M. Vogl, and A. J. Wagoner Johnson, “The Influence of Micropore Size on the Mechanical Properties of Bulk Hydroxyapatite and Hydroxyapatite Scaffolds,” Journal of the Mechanical Behavior of Biomedical Materials, 2:5, 560-570, 2009. Listed in the most cited 25 articles in journal since 2009 (up to at least 12/08/14).
• Lee, J. S., A. Wagoner-Johnson, and W. L. Murphy, "Modular Peptide Growth Factors for Substrate-Mediated Stem Cell Mediated Differentiation," Angewandte Chemie International Edition 121:6384-6387, 2009. Listed as "hot topic" by editor.
• Lan Levengood, S., S. Polak, M. B. Wheeler, A. Maki, S. G. Clark, R. D. Jamison, and A. J. Wagoner Johnson, "Multiscale Osteointegration as a New Paradigm for Bone Scaffold Design," Biomaterials, 31, 3552-3563, 2010.
• Lee, J. S., A. J. Wagoner Johnson, and W.L. Murphy, "A Modular, Hydroxyapatite-binding Version of Vascular Endothelial Growth Factor," Advanced Materials, 22, 48, 5494–5498, 2010. Featured for inside cover image.
• Ramachandra Rao, R. A., K. C. Toussaint, and A.J. Wagoner Johnson, "The Effect of Keratoconus on the Structural, Mechanical, and Optical Properties of the Cornea," Journal of Mechanical Behavior of Biomedical Materials, 4, 223-226, 2011. Invited. Top 25 hottest articles in JMBBM for Spring 2011 (April -June).
• Polak, S. J.,S. K. Lan Levengood, M. B. Wheeler, A. J. Maki, S. G. Clark, and A. J. Wagoner Johnson,"Analysis of the roles of Microporosity and BMP-2 on Multiple Measures of Bone Regeneration and Healing in Calcium Phosphate Scaffolds," Acta Biomaterialia,7(4),1760-1771, 2011.
• Poellman, M. J., K. L. Barton, S. Mishra, and A. J. Wagoner Johnson, "Patterned Hydrogel Substrates for Cell Culture with Electrohydrodynamic Jet Printing," Macromolecular Bioscience, 11(9), 1164-1168, 2011. Cover for September 2011 issue.
• Hoelzle, D. J., S. R. Svientek, A. G. Alleyne, and A. J. Wagoner Johnson, "Design and Manufacture of Combinatorial Calcium Phosphate Bone Scaffolds," ASME Journal of Biomechanical Engineering, 133(10), 101001, 2011. Most downloaded article for November 2011. Cover for October 2011 issue.
• Poellmann, M. J., E. K. Chien, B. L. McFarlin, and A. J. Wagoner Johnson, "Mechanical and Structural Changes of the Rat Cervix in Late-stage Pregnancy," Journal of the Mechanical Behavior of Biomedical Materials, 17, 6 6 – 7 5, 2013.
• Mahmoud, H., A. Wagoner Johnson, B. McFarlin, E. Chien, and M. Poellmann, "System-level biomechanical approach for the evaluation of term and preterm pregnancy maintenance," J Biomech Eng, 135(2):021009, 2013.
• Lau, T. Y., H. K. Sangha, E. K. Chien, B. L. McFarlin, A. J. Wagoner Johnson, and K. C. Toussaint, "Application of Fourier transform-second-harmonic generation imaging to the rat cervix," Journal of Microscopy, 251(1), 77–83, 2013.
• Polak, S. J., L. E. Rustom, G. M. Genin, M. Talcott, and A.J. Wagoner Johnson, "A mechanism for effective cell-seeding in rigid, microporous substrates," Acta Biomaterialia 9, 7977–7986, 2013.
• Poellmann, M. J. and A.J. Wagoner Johnson, "Characterizing and Patterning Polyacrylamide Substrates Functionalized with N-Hydroxysuccinimide," Cellular and Molecular Bioengineering, 6(3), 299-309, 2013.
• Poellmann, M. J., J. B. Estrada, T. Boudou, Z. T. Berent, C. Franck, and A. J. Wagoner Johnson, "Differences in morphology and traction generation of cell lines representing different stages of osteogenesis," J Biomech Eng, 137(12), 124503, 2016.
• Xie, Y., L.E. Rustom, A.M. McDermott, J.D. Boerckel, A.J. Wagoner Johnson, A.G. Alleyne, and D.J. Hoelzle, "Net shape fabrication of calcium phosphate scaffolds with multiple material domains," Biofabrication, 8, 015005, 2016. dx.doi.org/10.1088/1758-5090/8/1/015005.
• Rustom, L.E., T. Boudou, S. Lou, I. Pignot-Paintrand, B. W. Nemke, Y. Lu, M. Markel, C. Picart, and A. J. Wagoner Johnson, "Micropore-induced Capillarity Enhances Bone Distribution in vivo in Biphasic Calcium Phosphate Scaffolds," Acta Biomaterialia 44, 144-154, 2016. doi:10.1016/j.actbio.2016.08.025
• Randrianandrasanal, M., W. Y. Wu, D. A. Carney, A. Wagoner Johnson, and M. R. Berenbaum, "Structural and mechanical properties of cocoons of Antherina suraka, an endemic species used for silk production in Madagascar," Journal of Insect Science, 17(1), 1–8, 2017. doi: 10.1093/jisesa/iew112.
• Rustom, L. E., T. Boudou, B. W. Nemke, Y. LU, D. J. Hoelzle, M.D. Markel, C. Picart, and A. J. Wagoner Johnson, "Multiscale porosity directs bone regeneration in biphasic calcium phosphate scaffolds," ACS Biomaterials Science & Engineering, 3, 2768-2778, 2017. Invited for special volume on Multiscale Biological Materials and Systems: Integration of Experiment, Modeling, and Theory.
• Rahman, M.H., E. Currier, M. Johnson, R. Goding, A. J. Wagoner Johnson, and M. Kersh, "Primary and secondary consequences of rotator cuff injury on joint stabilizing tissues in the shoulder," Journal of Biomechanical Engineering, 139, 110801-1, 2017.  Featured in special issue highlighting young researchers (Kersh).
• Ho-Shui-Ling, A., Bolander, J., Rustom, L.E., Wagoner Johnson, A., Luyten, F.P., Picart, C., "Bone regeneration strategies: Engineered scaffolds, bioactive molecules and stem cells current stage and future perspectives," Biomaterials, 180, 143, 2018.
• Rustom, L.E, M.J. Poellmann, A.J. Wagoner Johnson, "Mineralization in Micropores of Calcium Phosphate Scaffolds," Acta Biomaterialia, 83, 435, 2019. Invited.
• Ostadi Moghaddam, A., J. Wei, J. Kim, A. C. Dunn, and A. J. Wagoner Johnson, "An indentation-based approach to determine the elastic constants of soft anisotropic tissues," Journal of the Mechanical Behavior of Biomedical Materials, 103, 103539, 2020.
• Lee, W., A. Ostadi Moghaddam, B. L. McFarlin, A. J. Wagoner Johnson and K. C. Toussaint, "Quantitative Classification of 3D Collagen Fiber Organization from Volumetric Images," IEEE Transactions on Medical Imaging, 39, 12, 4425-4435, 2020.
• Panthan, P., D. L. Armstrong, C. M. Valero, J. Bodnariuc, O. Haupt, A. Wagoner Johnson, L. Underhill, R. V. Iozzo, B. Lechner, D. E. Wildman, "Transcriptomic Profiling of Fetal Membranes of Mice Deficient in Biglycan and Decorin as a Model of Preterm Birth," Biology of Reproduction, ioaa205, 2020.
• Armstrong, A., A. G. Alleyne, A. J. Wagoner Johnson, "1D and 2D error assessment and correction for extrusion-based bioprinting using process sensing and control strategies," Biofabrication, 12(4):045023, 2020.
• Lee, W. A. Ostadi Moghaddam (co-first authors), S. Shen, H. Phillips, B. L. McFarlin, A. J. Wagoner Johnson, K. C. Toussaint, Jr. (Co-corresponding authors), "An optomechanogram for assessment of the structural and mechanical properties of tissues," Scientific Reports, 11, 324, 2021.
• Armstrong,  A. A., A. Pfiel, A. G. Alleyne, A. J. Wagoner Johnson, "Process monitoring and control strategies in extrusion-based bioprinting to fabricate spatially graded structures," Bioprinting, 21, e00126, 2021.
• Ostadi Moghaddam, A., Z. Lin, M. Sivaguru, H. Phillips, B. L. McFarlin, K. C. Toussaint, A. J. Wagoner Johnson, "Heterogeneous microstructural changes of the cervix influence cervical funneling," Acta Biomaterialia, 140, 1, 434-445, 2022.
• Levenstein, M., K. Marhaver, Z. Quinlan, H. Tholen, L. Tichy, J. Yus, I. Lightcap, L. Wegley Kelly, G. Juarez, M. Vermeij, A. Wagoner Johnson, "Engineered Substrates Reveal Species-Specific Inorganic Cues for Coral Larval Settlement," ACS Sustainable Chem. Eng. 10, 12, 3960–3971, 2022.
• Levenstein, M., D.J. Gysbers, K. Marhaver, S. Kattom, L. Tichy, Z. Quinlan, H. Tholen, L. Wegley Kelly, M. Vermeij, A. Wagoner Johnson, G. Juarez, "Millimeter-scale topography facilitates coral larval settlement in wave-driven oscillatory flow," PLoS ONE 17(9): e0274088, 2022.

Teaching Honors

• Society of Women Engineers, Outstanding Engineering Educator Award, 2020
• Rated as Outstanding on the list of Teachers Ranked as Excellent, Spring 2019 (598 Course Science Communication for Mechanical Engineers with 4.9 on Items 1 and 2)
• MechSE Two-Year Effective Teaching Award(requires student letters), 2018
• List of Teachers Ranked an Excellent, Fall 2016, 2017, 2018, 2021; Spring 2019
• Campus Award for Guiding Undergraduate Research, 2013
• Amy L Devine Recognition Award from Alpha Omega Epsilon for "being a passionate engineering professor and outstanding advisor," 2009.
• Engineering Council Award for Excellence in Advising, 2009, 2012, 2020

Research Honors

• American Institute for Medical and Biological Engineering Fellow (AIMBE), 2022
• Grainger College of Engineering Award for Sustained Excellence in Diversity, Equity and Inclusion, 2022
• Andersen Faculty Scholar, 2020
• Dean's Award for Excellence in Research, 2018
• Invited Professor, University of Grenoble, 2016-2017
• Center for Advanced Study Associate 2017-2018
• Chair of Excellence (2014-2017), NanoScience Foundation, Grenoble, France