Ann Saterbak

Adhesion Mediated by Bonds in Series

Cell adhesion in physiological situations and biotechnological applications is often mediated through serial protein/protein linkages. The adhesion strength of cell/substrate contacts through receptor/ligand bonds in series is explored with a simple mathematical model and quantified with an experimental adhesion assay. A deterministic, mass‐action model is developed to describe the attachment and detachment of cell/substrate contacts through single and serial bonds. The experimental system is comprised of protein‐coated beads, soluble antibody linkers, and an antibody‐coated glass surface. Using the Radial‐Flow Detachment Assay, the adhesion strengths of bead/substrate contacts through single and serial linkages are measured. Taken together, this work shows that the specific adhesion strength of the cell/substrate contacts comprised of two receptor/ligand bonds in series is less than the specific adhesion strength of the cell/substrate contacts comprised of either of the bonds separately. In addition, the force to rupture contacts comprised of bonds in series varies with the concentration of the solution linker. The model predicts that the locus of linkage fracture location has only a mild dependence on the ratio of relative bond affinities.

Integrating communication into the bioengineering curriculum

Oral, written, and visual communication assignments have been successfully integrated into the curriculum in the Department of Bioengineering at Rice University. Since most of the undergraduate courses in the Bioengineering Department have been developed in the last four years, the opportunity existed to build a strong sequence of communication activities into the curriculum and individual courses. Faculty who specialize in communication training from the Cain Project were available to collaborate in course design, implementation, and evaluation of communication projects in courses. Seven of the eight core Bioengineering courses require communication projects; three of the most popular track electives have significant communication components. Written communication assignments include design reports, research papers, short technical reports, and technical memos. Oral and visual communication assignments include presentations and posters. Both team and individual assignments have been developed. Since faculty efforts to teach communication are coordinated, assessment is conducted within a course and across the Bioengineering curriculum.

Laboratory courses focused on tissue engineering applications

Two new laboratory courses focused on tissue engineering have been developed and implemented in the Bioengineering Department at Rice University. The content of these courses is quite unique, yet fully supports the departments emphasis on biomedical engineering at the molecular, cellular, and tissue levels. This sequence or required undergraduate laboratory courses is designed to teach students mammalian tissue culture techniques, to develop their ability to design and conduct experiments, and to meet department-specific ABET Program Outcomes. In BIOE 342, students learn sterile technique, develop their ability to visually assess cell morphology and confluency, and learn how to maintain cells in culture. Using fibroblast cells, students conduct viability, attachment, and proliferation assays. In BIOE 441 students apply their tissue culture techniques to a tissue engineering challenge. Students assess the physical and chemical properties of two polymers. Students design and conduct experiments to quantify the viability, attachment, and proliferation of fibroblast cells on polymer films. Students are not given protocols for these experiments; they must develop new protocols or adapt protocols from BIOE 342 and make adjustments for experimental differences. Most students repeat experiments with a redesigned protocol. Because of the open-ended nature of the assignment, students develop unique approaches and protocols.

Cellular and molecular engineering curriculum at Rice University

The tremendous advances in cellular and molecular biology over the last 25 years have fundamentally changed our understanding of living organisms. This new understanding at the level of cells and their array of associated molecules is having a tremendous impact on both medicine and technology. Appreciating the complexities of the cell and its inner workings will be crucial to turning our knowledge into effective treatment strategies at the tissue, organ and whole individual levels. With this in mind, the Bioengineering Department at Rice University is developing a curriculum that educates students in cellular and molecular processes and their control. In this talk, we will describe the structure of the Bioengineering undergraduate program at Rice University and the development of a series of new courses for the cellular and molecular engineering track. This series of courses starts with the basic concepts of engineering fundamentals at the sophomore level. This introductory course provides the foundation for the more advanced quantitative treatment of cell structure and function at the cellular and tissue levels taught in the junior and senior levels. We will discuss the development of three specific courses that cover topics ranging from molecular to tissue level. This sequence of courses exposes students to the cutting-edge synthesis of molecular and cellular information into design of tissue systems.

Using a Teaching Intervention and Calibrated Peer Review™ Diagnostics to Improve Visual Communication Skills

Rice University’s bioengineering department incorporates written, oral, and visual communication instruction into its undergraduate curriculum to aid student learning and to prepare students to communicate their knowledge and discoveries precisely and persuasively. In a tissue culture lab course, we used a self- and peer-review tool called Calibrated Peer Review™ (CPR) to diagnose student learning gaps in visual communication skills on a poster assignment. We then designed an active learning intervention that required students to practice the visual communication skills that needed improvement and used CPR to measure the changes. After the intervention, we observed that students performed significantly better in their ability to develop high quality graphs and tables that represent experimental data. Based on these outcomes, we conclude that guided task practice, collaborative learning, and calibrated peer review can be used to improve engineering students’ visual communication skills.

Mechanical Wheelchair Propulsion System for Patients With Arthrogryposis

Arthrogryposis is a congenital disorder characterized by extreme joint stiffness that inhibits strength and flexibility in upper and lower extremities. Cases vary in severity, but this research focuses on those in which patients require a wheelchair for mobility. Currently, two conventional designs exist: mechanical and electric wheelchairs. For most arthrogryposis patients, existing mechanical wheelchairs are insufficient for independent propulsion as their joints are severely impaired, prohibiting them from reaching the outer handrails on the wheels and expending enough force to propel and steer. Existing devices that improve the mechanical advantage of wheelchairs are insufficient for the needs of these patients who have very limited and specific ranges of motions, which are not compatible with the required force inputs. Though electric wheelchairs allow independent mobility, they are expensive to maintain and not easily portable, limiting their use by socioeconomically disadvantaged patients.Arthrogryposis patients require a lightweight, portable and durable mechanical wheelchair that takes advantage of the user’s specific strengths, and is easily maneuvered in all directions without assistance. A design is presented for a socioeconomically disadvantaged teenage client with arthrogryposis. After taking data regarding the ranges of motion and strength of the client, a new propulsion system was designed and retrofitted to a conventional wheelchair. Prototye I has been tested and a second-generation design which fits the needs of a wider audience suffering from arthrogryposis is presented.Copyright