New Project: Mechanics and Trophoblasts
Cambridge University recently launched a Centre for Trophoblast Research. We are currently exploring pilot projects in trophoblast research with a bioengineering twist.
Mechanical Failures in Obstetrics
Preterm premature rupture of the placental membranes is associated with one third of premature births. It has been demonstrated that the mechanical properties of prematurely failed membranes are not different from membranes of the same gestational age which have remained intact. Therefore, membrane failure is a local process which can be explored in terms of local changes in structure and properties of isolated portions of the membrane. Factors including local membrane thickness changes, gestational age, delamination of the chorioamnion bilayer, and local alterations in amnion microstructure (at the length- scale of the collagen network) are being examined in the context of the membrane fracture behavior. Understanding of these factors may allow for pre-failure diagnosis of membrane weak spots, thus opening the door for potential intervention and treatment techniques for preterm membrane rupture.
New Project: Biomimetic materials
Natural materials are formed on different principles than most engineering materials. They are synthesized under gentle conditions, with little energy used in their formation and are always composites. We are working to extract principles in natural materials for use in design of new materials for applications ranging from medicine to architecture.
Mineralized Tissues as Composite Materials
Even the structurally simplest of biological tissues are composite materials: soft tissues are composed of proteins, sugars and water while mineralized (hard) tissues are composed of these components plus a large volume fraction of mineral (a carbonated apatite or dahllite). In mammals the ubiquitous fibrillar protein collagen is the dominant protein present. Due to the composite nature of tissues, there has been considerable recent interest in modeling the structure-properties relationships (particularly in mineralized tissues) in a manner analogous to that used for study of traditional engineering composites.
New Project: Poroelastic nanoindentation of bone and hydrogels
Nanoindenters were designed for characterization of stiff, hard and dry materials. We’re not going to let that stop us–ongoing work uses nanoindentation to map out properties of wet bones and soft hydrogels. Emphasis is on advanced material models, such as poroelasticity, for deconvolution of material properties.
New Project: Indentation for Cancer Diagnosis
Doctors like to “indent” their patients to look for stiff tissue regions, which are indicative of pathological processes such as fibrosis and cancerous tumors. Sometimes it’s difficult to distinguish between fibrosis and fibrillation when a stiff region is identified, and this may be important in better diagnosis of cancer. We are just starting a new project to examine the potential for instrumented indentation in differential diagnosis ex vivo.
Past Projects
Viscoelastic Nanoindentation of Polymers
Cartilage Tissue Engineering
Impact Biomechanics
This work included studies of ex vivo impact of cartilage, examining the interaction between cell death and mechanical loading. Later work also included mechanical characterization of costal cartilage of the ribcage, which may be important in changes with how the ribcage deforms as we age.
Copyright © 2008, Michelle L. Oyen
Revised: October 6, 2008
