Our Team

Kristen L. Billiar, Ph.D.

John Woodman Higgins Professor in Biomedical Engineering, Principal Investigator, and Department Head

Dr. Billiar is intrigued by mechanobiology, the way in which mechanical forces regulate the development and healing of connective tissues and the pathogenesis of disease. Currently the Department Head in Biomedical Engineering, Dr. Billiar joined the WPI faculty in 2002, after receiving a Ph.D. in Bioengineering at the University of Pennsylvania and working as a staff engineer at Organogenesis, Inc. A Fulbright Scholar, Dr. Billiar also received WPI's Romeo L. Moruzzi Young Faculty Award for Innovation in Undergraduate Education in 2005 and the Trustee’s Award for Academic Advising in 2008.

Ying Lei, Ph.D.

Post Doctoral Fellow

Ying joined the Tissue Mechanics and Mechanobiology Lab at WPI in January 2017 as a postdoctoral fellow. She is investigating how different biomaterials affect the mechanical environment that cells can sense, and how cells react to and modify the mechanical extracellular environment. She earned a Ph.D. degree in Mechanical Engineering at the University of Tennessee, Knoxville (UTK), where she built a biaxial stretch bioreactor, and studied how mechanical stimulation can influence the extracellular matrix remodeling in native and engineered aortic heart valve tissues. Ying also got a Master's and a Bachelor's degree in Aerospace Engineering from Beihang University (BUAA), where she researched the simulation of fluid-structure interactions and bone fractures.

Juanyong Li

Ph.D. Student

Juanyong joined the Billiar Lab in August 2019. He earned his B.S. degree in Mechanical Engineering in 2016 at Central South University in China. In 2018, he earned his M.S. degree in Mechanical Engineering at Boston University and continued working there as a visiting researcher. Before coming to WPI, his research consisted of investigating the effects of different factors on the ability of multicellular clusters to maintain tensional homeostasis.

    Rozanne Mungai

    Ph.D. Student

    Rozanne earned her Bachelor of Science in Biological Engineering at the Massachusetts Institute of Technology in 2017 and moved on to work at Tufts University as a Research Technician. At Tufts, she studied extracellular matrix remodeling and the host-graft response using iPS cell-seeded silk scaffolds for regenerative cardiac tissue engineering. She joined the Billiar Lab in August 2019 where she has been studying the role of the heart valve microenvironment in influencing cellular repopulation of tissue-engineered heart valves. Her research is focused on uncovering the role that cyclic stretch plays in cell invasion.

      Alexandra Taylor

      Alexandra is a master’s student, who received her B.S in Biomedical Engineering at WPI in 2023, continuing at WPI to receive her M.S in 2024 in the same discipline. She joined the lab in 2022 as an MQP student and is continuing the project to complete her Master’s Project. Her project is manufacturing and validating a microfluidic bioreactor to study the effects of shear stress within the environment of a tissue engineered heart valve. She is passionate about the research and development of cardiovascular devices.

        Ava Mattimore

        Ava, an undergraduate student at WPI, joined the Billiar lab in the spring of 2023. She is pursuing a Bachelor's degree in Biomedical Engineering, expected to graduate in 2025. In addition to her research in the lab, Ava is actively involved in various campus activities. She serves as a campus tour guide and is active with WPI’s Electric Guitar Innovation Lab. Ava also plays the cello in WPI's orchestra. Her current role in the lab involves investigating the impact of stiffness and dynamic stretching on cells.

          Owen Beaver

          Undergraduate Student

          Owen joined our lab as an undergraduate in February 2023. He will be graduating in May 2025 with a B.S. in Biomedical Engineering and a minor in Computer Science. In the lab, Owen's research focuses on cell death induced by mechanical stimuli,  although he spent the summer at Dana Farber in a cancer immunotherapy lab. There, he studied how natural killer cells demonstrate enhanced function when exposed to cytokines in the tumor microenvironment.

            Jessica Vo

            Jessica first joined the Billiar Lab in December 2022 as an undergraduate student at WPI. She is working towards her B.S. in Biomedical Engineering and B.S. in Mechanical Engineering. In the lab, she is currently working on cell migration in microfluidic chips.

              Luciano Bortolin

              Former Master's Student

              Originally from Buenos Aires, Argentina, Luciano graduated from the MS in Biomedical Engineering program at WPI in 2016. His thesis was titled  "Fibrin based tissue constructs for valvular mechanobiology studies and the effect of hyaluronic acid in cell generated tension". Upon his return to Argentina, he was a professor in the laboratory of Tissue Engineering at Instituto Tecnológico de Buenos Aires, and a lecturer at Universidad Favaloro. Currently, he is working at Philips Healthtech, providing support on medical devices for South American countries.

                Samantha Havel

                Former Undergraduate Student

                Sam joined the Billiar lab in June 2021. She graduated in May 2023 with her B.S. in Biomedical Engineering. In addition to our lab, she worked in the Student Activities Office and was a Community Advisor. Her research focused on a microtissue conditioning device.

                  Ranya Basma

                  Former Undergraduate Student

                  Ranya Basma graduated from Worcester Polytechnic Insititute in May 2022 with a Bachelor of Science in Biomedical Engineering. She also pursued a minor in Global Public Health. Ranya was a member of the Women's Varsity Soccer Team and spent the summer of 2021 in our lab working on updating the existing system for the biaxial testing device.

                    Colin W. Coutts

                    Former Master's Student

                    Colin joined the Billiar lab in May 2020. He earned his bachelor’s degree in Biomedical Engineering in 2020 and his master's degree in Biomedical Engineering in 2021, both from Worcester Polytechnic Institute. Colin joined our team for his master's studies, where he studied the calcification of the aortic heart valve in 3D models.

                      Alena Lukovnikova

                      Former Undergraduate Student

                      Alena started her studies at WPI in 2019 as a pre-med student. She earned her B.S. in Biomedical Engineering in 2023. In the lab, she worked on aortic heart valve calcification.

                        Mathilda Lutynski

                        Mathilda graduated from Tufts University in 2007 with a Bachelor of Science in Mechanical Engineering, and from WPI in 2012 with a Master of Science in Biomedical Engineering.  During her time in our lab, she focused on identifying whether a 2-D nonlinear finite element model would correlate to experimental cell mechanical behavior on fibrous gela.  She has since been a Mechanical Engineer in the medical device industry, developing implants and instruments for total joint replacements and arthroscopic surgery.

                          Jenna Balestrini, Ph.D.

                          Former Ph.D. Candidate

                          Jenna completed her Ph.D. at WPI in 2009, and continued her research as a Post Doctoral fellow at the University of Toronto for two more years. After that, she became a research associate scientist at Yale School of Medicine from 2012 to 2016. Jenna now works at Danaher Life Sciences.

                            Ngozi Eze, Ph.D.

                            Former Postdoctoral Fellow

                            Dr. Ngozi A. Eze is an alumna of MIT undergrad (Chemistry) and completed her Ph.D. studies in Materials Science & Engineering at Georgia Tech. Her Ph.D. research focused on engineering synthetic oligonucleotides to be stable and functional under physiologically relevant conditions for a biomaterials context. Dr. Eze then worked as a Postdoctoral Fellow and Lab Manager in Biomedical Engineering at WPI in the lab of Prof. Kris Billiar. Her research in the Billiar lab focused on using optical and confocal microscopy to probe the connection between the microenvironment experienced by cells growing on hydrogels and apoptosis, to better understand the etiology of calcific aortic valve disease (CAVD). She then returned to MIT for three years as a Research Specialist at the Koch Institute for Integrative Cancer Research, writing research grant proposals for funding on topics in cancer research, Biological Engineering, and Materials Science & Engineering; and assisting researchers with their patent applications and technology commercialization ventures. Dr. Eze will join the intellectual property law firm Clark+Elbing as a Technology Specialist, assisting attorneys with patent protection strategies in Biomedical Engineering.

                              Heather Cirka, Ph.D.

                              Former Postdoctoral Fellow and Ph.D. Candidate

                              Heather Cirka studied in the Billiar Lab from 2010 to 2016 when she graduated with her Ph.D. She entered the lab with a keen interest in studying mechanobiology and the mechanical determinations of cell fate. Her research in the lab focused on mechanical measurements of tissue properties; combining matrix stiffness with mechanical stretch in two-dimensional environments; and understanding the cellular mechanical response utilizing techniques of atomic force microscopy and traction force microscopy. She holds a patent with Prof. Billiar for a method she developed in the lab to measure the properties of soft/highly compliant, anisotropic, irregularly shaped tissue biopsies. She later expanded to multicellular mechanics and developed the Billiar Lab’s micro-contact printing protocols and in vitro model for calcific aortic valve disease. Heather was an American Heart Association Pre-Doctoral Fellow from 2012 to 2014 and an NSF Integrative Graduate Research Education and Training (IGERT) Fellow from 2014 to 2016. Through the IGERT program, Heather developed an interest in technology transfer and start-ups and successfully pitched her research as a potential investment opportunity in the University-wide “Investing in Ideas with Impact” competition. After completing her Ph.D., Heather started her professional career as a Post-Doctoral Fellow in the Billiar Lab by supporting several collaborations with the McCollum Lab at the University of Massachusetts Medical School. Heather now works as an R&D Engineer for Boston Scientific. During her free time, Heather enjoys running, hiking, swimming, and spending time outside with her husband John, and her dog Piper.

                                Mahvash Jebeli

                                Former Ph.D. Candidate

                                Mahvash earned her Bachelor’s Degree in Mechanical Engineering from the University of Tehran in 2013 and a Master's Degree in Biomedical Engineering from AmirKabir University of Technology (Tehran Polytechnic) in 2015. There she studied human gait, validating the KinectV2 system in comparison to Vicon system for use as a motion capture system in the health industry. She then earned a second Master's Degree at the University of Akron in May 2019, where she studied the mechanical properties of the tricuspid valve when under biaxial and uniaxial loading conditions. Mahvash then joined our team for her Ph.D. studies, where she studied the calcification of the aortic heart valve. She earned her Ph.D. in Biomedical Engineering from WPI in 2022, defending her dissertation titled, "Investigating the Role of Apoptosis in Calcification of Aortic Valvular Interstitial Cells." She now works at Seres Therapeutics.

                                Zhijie Dong

                                Former Master's Student

                                Zhijie joined the lab in February 2019. She graduated from WPI in May of 2020 with a B.S. in Biomedical Engineering and a B.S. in Mechanical Engineering. She is currently pursuing her Master of Engineering in Biomedical Engineering. Her current research involves fibrin-based hydrogel heart valve constructs.

                                Leigh Whitehorn

                                Former Undergraduate Student

                                Leigh graduated from WPI in May 2020 with a B.S. in both Biomedical Engineering and Mechanical Engineering. She was with the lab from her throughout her time at WPI, and dove for the school's diving team. In the lab, she studied how mechanical inputs (such as stretching and/or substrate stiffness) change various cell behaviors, such as cell elongation, orientation, and overall health.

                                Leo Sutter

                                Former Master's Student

                                Leo studied the effect of mechanical strains on multicellular aggregates. Before WPI, he earned a B.S. in Physics from the Rochester Institute of Technology. As an undergraduate, Leo worked on computational simulations of systems such as cartilage and cell monolayers. He received his M.S. in Biomedical Engineering from WPI in 2020 and is pursuing his Ph.D. at the University of Minnesota.