People:  Graduate Students:  Foteini Makrydaki
Foteini Makrydaki

Degree: Ph.D., Chemical Engineering
Advisor: Christos Georgakis
Research Project: Data Driven Stoichiometric & Kinetic Modeling in Complex Chemical & Biological Reaction Systems

Project Description:
Complex Reaction Systems consist of a large number of species whose concentration change over time is affected by several interactions that are often not well-understood due to our limited knowledge of the stoichiometry and related reaction kinetics. The reactions involved in the production of active pharmaceutical ingredients are one example of a Complex Reaction System of particular interest in our research group.  If the reactions related to the production of a drug in the development stage are studied and understood reasonable well then the design of the related manufacturing processes can be done with less uncertainty and within a shorter time period.

The methodology under development aims to achieve the detailed understanding of their Stoichiometric and Kinetic characteristics from high throughput experimental data and the rapid development of an accurate process model. This model and its accuracy description can then be used to define the operational space of the process critical for FDA approvals and the proper operation the process. 

Our group has developed in the past systematic approaches in discovering the stoichiometric models that are consistent with the experimental data at hand. The mathematical methods used to acquire the Stoichiometric Model are Singular Value Decomposition (SVD) applied to the changes in the reactants and Structured Target Factor Analysis (STFA) to test for the possible reactions taking place.  This methodology is currently tested and extended to apply in cellular systems, to discover the active pathways of a metabolic network that describe interactions between different proteins whose concentration changes we measure.  At the same time a lot of work has been done on the development of efficient nonlinear parameter estimation algorithms if the kinetic expressions of the involved reactions are known.

The main objective of this research project is to develop a general methodology for the identification of the most appropriate kinetic form that accurately describes the experimental data of a complex reaction.  Initially simple kinetic models are postulated and fitted to the available data. Methods are under development to identify the structural model-data mismatch and thus iterate the kinetic forms to an incrementally more complex one, until the structural model-data mismatch is minimized.  If more than one model is describing the data equally accurately, then a new set of experiments is designed for resolving which the more accurate model is.  A final goal of this research investigation is to be able to do the modeling concurrently with the data collection; something that we have termed as online modeling.

Education & Experience:
M.S. in Chemical Engineering, National Technical University of Athens (NTUA), 2004
Research Assistant, Bayer AG - Bayer Technology Services, Leverkusen, Germany (2004)
Engineering Trainee, SC Johnson, Athens, Greece (2003)
Engineering Trainee, Fraunhofer Institute, Freising, Germany

Funding:
Tufts University

Graduate Students:

Fernando Lima
Foteini Makrydaki
Praveen Prasanna
Lisa Schupmann
Sze Wing Wong