Ozan Akkus, PhD, Associate Professor
Research Interests:
Bone/tendon/ligament substitute biomaterials and tissue engineering; mechanobiology; mechanical properties of bone tissue.
The focus of the Akkus lab is on musculoskeletal biomaterials and mechanobiology. In the biomaterials realm, the lab has developed an electrochemical fabrication method for the generation of a strong and dense collagenous tissue analog, called electrochemically aligned collagen (ELAC). ELAC's strength approximates that of tendon/ligament, and emerging results indicate that ELAC supports the differentiation of mesenchymal stem cells to tenocytic lineage. The trajectory of this project into the future includes the development of transplant-ready constructs based on ELAC which will encompass bony ends to promote osteogenic and tenogenic differentiation on the same platform. In the mechanobiology realm, the lab has been breaking ground in understanding the role of VEGF in osteogenesis by studying 3D cultures of ossifying bone marrow explants.
Dwight Davy, PhD, Professor
Research Interests:
Mechanics of hard tissues, mechanics of fracture healing and bone grafts, mechanics of natural and artificial joints.
Dr. Davy’s research interests are in biomechanical behavior of hard tissues and skeletal joints. These include the mechanics of bone, particularly the nonlinear behavior of bone, as well as reconstruction of skeletal systems, including fracture treatment and repair, total joint replacements, and reconstruction with bone grafts and graft substitutes.
Recent focus has been on the experimental measurement and theoretical modeling of the damage accumulation process in bone. Current studies include the characterization of damage effects across loading modes (tensile damage effects on compressive, torsional properties, etc.), and in combined loading modes (tension+torsion, compression+torsion damage effects).
Other studies have examined the modeling of damage evolution in cancellous bone and the characterization of anisotropic damage accumulation in cancellous bone. In addition, recent work has looked at damage accumulation and failure at extremely high loading rates.
Other work involves the incorporation of damage effects into the analysis of bone-implant systems and the inclusion of these effects in predicting fracture risk in diseased bone and in reconstructed skeletal systems.
Community of Science Profile
E-mail: mailto:dtd@po.cwru.edu%20
Joseph M. Mansour, PhD, Professor
Research Interests:
Mechanical behavior of cartilage including effects of disease and repair. Experimental and theoretical models of musculoskeletal tissues and structures.
Dr. Mansour’s research concerns the mechanical behavior of soft tissues, focusing primarily on tissue engineered and native cartilage. Material properties are evaluated primarily using indentation, a method best suited to the small samples typically obtained from experimental animals such as the rabbit.
Testing procedures based on reduction of strength due to repeated loading are also used. In the joint or other configuration, the structural properties of the material may sometimes be more important than material properties. The recently demonstrated ability to grow relatively large (centimeter sized) pieces of cartilage in the Skeletal Research Center has opened up several opportunities related to evaluation of tissue mechanics.
With these larger samples it is possible to perform tests that cannot be performed if only small samples are available. This opens the opportunity for developing and implementing more meaningful evaluation procedures than have been used in the past. There are also opportunities related to evaluation of native cartilage, particularly as related to in vivo animal models of osteoarthritis. Furthermore, we have developed methods to evaluate changes in knee kinematics in rabbit OA models.
E-mail: mailto:jmm12@po.cwru.edu%20
Clare M. Rimnac, PhD, Professor
Research Interests:
Implant materials performance, wear and degradation of UHMW polyethylene, implant retrieval analysis and implant design, mechanical performance of normal and diseased bone tissue.
Dr. Rimnac’s research encompasses mechanical behavior of polymeric biomaterials, orthopaedic implant retrieval analysis, and mechanical behavior of hard tissue. The mechanical behavior of polymeric biomaterials research has been directed towards the mechanical and clinical performance of ultra high molecular weight polyethylenes (non-crosslinked and crosslinked) used in orthopaedic total joint replacements and poly(propylene fumarate) used in the manufacture of bioresorbable scaffolds for hard tissue regeneration and repair.
There is an overall emphasis on understanding in-vivo failure mechanisms and on methods of improving the long-term performance of these implant materials. Current research efforts include: constitutive modeling of polyethylenes used in total joint replacements; and design, manufacture, and validation of craniofacial three-dimensional (3D) scaffolds for repair of large structural bone defects using poly(propylene fumarate).
The implant retrieval analysis research involves failure and damage analysis of implants removed at revision surgery to determine the cause of failure and the mechanisms responsible for the damage, and the application of results in design analyses to improve the performance of implant designs under development.
The research on mechanical properties of hard tissue has been focused on examination of the contribution of damage accumulation at the ultrastructural and microstructural levels to the increase of skeletal fragility (particularly static and cyclic crack growth resistance) with age as affected by age-related changes in bone tissue composition.
E-mail: Clare.Rimnac@case.edu