Joseph M. Wallace, Ph.D.
Assistant Professor, Biomedical Engineering
Contact:
723 W. Michigan St. SL 220D
Indianapolis, IN 46202
Phone: (317) 274-2448
Fax: (317) 278-2455
E-mail: jmwalla@iupui.edu
Education:
B.S., Aerospace Engineering - Georgia Institute of Technology, 2002
M.S., Biomedical Engineering – University of Michigan, 2004
Ph.D., Biomedical Engineering – University of Michigan, 2007
Postdoctoral Training:
Nanoscale Morphology and Mechanics of Type I Collagen, University of Michigan, Department of Chemistry (2007-2010)
Research Area:
The primary research interests in our lab focus on understanding how biological and environmental factors influence the organization and assembly of bone. Bone is an exquisitely evolved biological material that, among other metabolic roles, serves important structural functions in the body. As a hierarchical material, bone has structural elements at multiple size scales. At its smallest hierarchical level of organization, bone is a two-phase composite material which represents the intimate interaction between organic and inorganic elements. However, the nanoscale size of these fundamental constituents of bone inhibits the roles of each component from being completely understood. Adding cellular and metabolic aspects further complicates the issue. In order to develop rational approaches for the diagnosis and treatment of defects, damage and disease of skeletal tissues, it is imperative that we understand the link between the biological and mechanical roles that these tissues play. Many groups work on structure/function relationships in bone. However, much of this work tries to develop relationships by linking properties from different hierarchical size scales (e.g. trying to correlate whole bone mechanical integrity with measures of tissue composition). Likely due to the disconnect in size scale between the different measures, these types of analyses fail to truly provide cause and effect relationships. By investigating structure/function relationships at discrete hierarchical levels and trying to understand how properties in one level influence the levels above it, the link between biology and mechanics can be elucidated.
Specific Lab Research Goals:
(1) Hierarchical mechanisms of disease in mineralized tissues
(2) Age-related effects of mechanical loading on the bone extracellular matrix: Relation to life-long fracture risk
(3) Nanoscale mechanisms of de novo tissue formation
The goal of this work is to translate findings into rational and clinically-relevant diagnostic and treatment options for defects, damage and disease of musculoskeletal tissues. To this end, our work focuses on tying morphology and composition to mechanical function at discrete size scales throughout bone’s hierarchical structure.
Experimental Methodologies:
Nanoscale: electron microscopy and atomic force microscopy to probe collagen morphology and mechanics.
Microscale: investigation of tissue composition using Raman Spectroscopy coupled with nanoindentation.
Macroscale: whole bone structure and mechanical function are assessed using µ-Computed Tomography, histomorphometry and whole bone fracture and toughness testing.
Selected Publications:
Wallace JM, Orr BG, Marini JC, Banaszak Holl MM, “Nanoscale Morphology of Type I Collagen is Altered in the Brtl Mouse Model of Osteogenesis Imperfecta,” Journal of Structural Biology, In Press: doi:10.1016/j.jsb.2010.08.003.
Wallace JM, Chen Q, Fang M, Erickson B, Orr BG, Banaszak Holl MM, “Type I Collagen Exists as a Distribution of Nanoscale Morphologies in Teeth, Bones and Tendons,” Langmuir, 2010; 26 (10): 7349-7354.
Wallace JM, Erickson B, Les CM, Orr BG, Banaszak Holl MM, “Distribution of Type I Collagen Morphologies in Bone: Relation to Estrogen Deficiency,” Bone, 2010; 46: 1349-1354.
Wallace JM, Golcuk K, Morris MD, Kohn DH, “Exercise Modulates the Phenotype of Biglycan-Deficient Mice in an Inbred Strain-Specific Manner by Altering Bone Composition and Mechanical Integrity,” Annals of Biomedical Engineering 2010; 38 (4): 1607-1617.
Hansma P, Yu H, Schultz D, Rodriguez A, Yurtsev E, Orr J, Tang M, Miller J, Wallace JM, Kang I, Kohn D, Buckley J,Weaver V,Lotz J,“Tissue Diagnostic Instrument,” Review of Scientific Instruments 2009; 80: 054303.
Wallace JM, Golcuk K, Morris MD, Kohn DH, “Inbred Strain-Specific Response to Biglycan Deficiency in the Cortical Bone of C57BL6/129 and C3H/He Mice,” JBMR 2009; 24 (6): 1002-1012.
Wallace JM, Ron MS, Kohn DH, “Short-term exercise in mice increases tibial post-yield mechanical properties while two weeks of latency following exercise increases tissue-level strength,” Calcif. Tis Int 2009; 84: 297-304.
Wallace JM, Rajachar RM, Allen MR, Bloomfield SA, Robey PG, Young MF, Kohn DH, “Exercise-Induced Changes in the Cortical Bone of Growing Mice are Bone and Gender Specific,” Bone 2007; 40 (4): 1120-1127.
Wallace JM, Rajachar RM, Chen XD, Shi S, Allen MR, Bloomfield SA, Les CM, Robey PG, Young MF, Kohn DH, “The Mechanical Phenotype of Biglycan Deficient Mice is Bone- and Gender-Specific,” Bone 2006; 39 (1): 106-116.
