Trainee: Catalina Ardila
Mentor: Jonathan Vande Geest, PhD
Co-Mentor: William Wagner, PhD
Catalina is part of the research team in Dr. Vande Geest’s laboratory that is working on the development of a small diameter tissue engineered vascular graft to use in coronary artery bypass surgeries as a therapy to treat acute coronary artery disease.
In order to fabricate the graft, we use a technique called electrospinning using biodegradabe natural and synthetic polymers such as gelatin, fibrinogen and PCL.
As part of this project Catalina has been working on the biocompatibility assessment of our electrospun grafts with the cells present in the native arteries such as smooth muscle cells (SMCs) and endothelial cells (ECs). The main goal has been to determine if SMCs and ECs can grow, function and preserve their phenotype when cultured in the biomaterials used to fabricate our vascular grafts.
As part of her research work, she has demonstrated that SMCs, when seeded on our graft material composed by 80% gelatin and 20% fibrinogen can proliferate and migrate all the way through the scaffold. Furthermore, when SMCs that have been cultured in the grafts are stimulated with TGFβ2 they present a switch in their SMCs phenotype depending on the TGFβ2 concentration. When stimulated with 0.1-3 ng/ml TGFβ2 the cells present a proliferative phenotype with little production of collagen. When stimulated with higher concentrations, 5-10 ng/ml, of TGFβ2 they move from a proliferative to a more synthetic phenotype where they present higher production collagen and their proliferation is limited.
Also as part of her work with ECs, she has demonstrated that by adding PCL to the polymeric mixture of gelatin and fibrinogen and by surface modified the graft by thermoforming and coating with ECM molecules, human cord blood derived endothelial cells (hCB-ECs) are able to form a stable monolayer in the graft surface. Also, we showed that the hCB-ECs that were growing in our grafts are able to produce nitric oxide synthase in static conditions, decrease the platelet deposition and activation and upregulate the production of ICAM-I and VCAM-I when stimulated with ILB-1β.
Catalina has been exploring the possibility of a graft that allows controlled release of TGFβ2 from the electrospun construct. She is currently performing experiments with grafts electrospun with human TGFβ2. These grafts have different compositions of PCL to gelatin and PCL to tropoelastin with the goal to assess how we can control de release of this cytokine by changing the ratio of natural and synthetic biopolymers in the graft.
- BIOENG 2023 – BIOENGINEERING SEMINAR SERIES*
- BIOENG 3760 – RES SEM: REGENERATIVE MEDICINE*
- MSCMP 2730 – Molec Mechs Tis Grwth & Diffrn*
- STAT 2220 – Applied Regression
- BIOENG 3997 – Research, PHD
Summer 2017: (registered for)
- MSCMP 3770 Cell Therapy*
*CATER requested courses
Honors and Awards
- Finalist, Master’s Student Paper competition, SB3C 2016 July 1st, physiology and diseases, cellular and tissue mechanics, biomaterial and material characterization category. (2016)
- Reviewer Choice award, BMES, annual meeting October 24th 2014 – Tissue Engineering Track. (2014)
Ardila, D. C., Tamimi, E., Danford, F. L., Haskett, D. G., Kellar, R. S., Doetschman, T., & Geest, J. P. V. (2015). TGFβ2 differentially modulates smooth muscle cell proliferation and migration in electrospun gelatin-fibrinogen constructs. Biomaterials, 37, 164-173. PMCID: PMC4312204
Tamimi E, Ardila DC, Haskett DG, Doetschman T, Slepian MJ, Kellar RS, Vande Geest JP, The effect of cross linking time on the tubular biaxial mechanical properties of electrospun gelatin/fibrinogen vascular constructs, Journal of Biomechanical Engineering, 2016 Jan 138(1):011001-1 – 011001-12. PMCID: PMC4844094
Presentations – Sept 2012 to present
Ardila D. C., Tamimi E., Acuña A., Doetschman T., Vande Geest J, , Cell Proliferation and Infiltration in Electrospun Non-Synthetic Biopolymer-Based Scaffolds for Tissue Engineering Applications, 2014 Biomedical Engineering Society Annual Meeting, October 22-25, San Antonio, TX
Catalina Ardila, Andrea Acuña, Ehab Tamimi, Tom Doetschman, Jonathan Vande Geest. Effect of Different Surface Modified Gelatin/Fibrinogen Electrospun Scaffolds on Endothelial Cells Growth, Biomedical Engineering Society Annual Meeting, 2015 Oct 7-10, Tampa, FL
Catalina Ardila, David Maestas, Victoria Lundine, Marvin Slepian, Jonathan Vande Geest , Surface modification of electrospun gelatin/fibrinogen scaffolds to encourage endothelial cell function, Summer Bioengineering, Biomechanics, and Biotransport Conference (SB3C), June 29-July2, 2016, National Harbor MD
Catalina Ardila, David Maestas, Victoria Lundine, Marvin Slepian, David Harris, Jonathan Vande Geest, Surface Modication of Electrospun Gelatin/Fibrinogen Scaffolds to Encourage Endothelial Cell Function, McGowan Institute for Regenerative Medicine Annual Retreat, Farmington, PA, March 2017
January 27th, CATER seminar, University of Pittsburgh, Pittsburgh PA, Towards the development of a tissue engineered vascular graft for coronary artery bypass surgeries
- Xizi Xiao, Undergraduate researcher, dissection of the pig and rabbit lamina cribosa to assess differences in shape between species, Spring 2017
- Kelsey Sadlek, Undergraduate researcher, decellularization of the pig and human lamina cribosa to use as a scaffold to assess gene expression changes in lamina cribosa cells at different scaffold stiffness and hydrostatic pressure, Fall2016-Spring 2017
- Corina MacIsaac, Undergraduate researcher, Rat aortic intrapositional surgeries of a TEVG, Fall 2015
- Jamie Hernandez, Undergraduate researcher, Development of a cell seeding device for tubular grafts, Fall 2015.
RCR Workshop attended
- Nov 2016 Data collection—Monitoring and reporting. CTSI, University of Pittsburgh, Pittsburgh, PA
Currently enrolled in the Department of Bioengineering Graduate Program, as a PhD candidate within the Swanson School of Engineering at the University of Pittsburgh.