Aim of the present project is the modelling and numerical simulation of soft-tissue growth in rotating bioreactors and related morphological evolution. Numerical simulations will be used as a relevant and suitable tool in the analysis of such dynamics.
The in vitro culture of 3D tissues under conditions that support efficient nutrition of cells is an important step towards the development of functional grafts for the treatment of lost or damaged body parts and/or to re-establish appropriate structure, composition and functions of native tissue.
The key factor in this new field of engineering involves how to define the properties of the artificial environments wherein biological tissues are grown in order to achieve the best possible conditions for growth [1,2]. Organic soft tissues are very sensitive to their environment and, if exposed to sufficiently severe conditions may denature and/or degrade. In general, they have to be constantly maintained in a thoroughly hydrated state at or near physiological pH and temperature. For these reasons, very gentle and restricted techniques must be used. In practice, the basic approach pursued by researchers for the in vitro cultivation of functional tissue equivalents is to mimic as much as possible the native cell environment and recapitulating processes during normal in vivo tissue development (this approach is generally based on bioreactor cultivation that provides facilitated transport of nutrients and metabolites, and provision of molecular regulatory factors).
Further progress in creating proper environments for the growth of the tissues requires a precise understanding of how all the chemical, mechanical and other environmental factors influence growth.
With this project, we propose an investigation into a variety of dynamics and effects produced by the interaction of a growing tissue with the external environment.
Aim of the present project is the introduction of fundamental correlations between in vitro cultivating conditions for soft tissues (e.g., cartilaginous tissue), cell response, and resulting morphological properties of the engineered tissue in order to provide strategies for optimal integrated design of bioreactor configuration and biomaterial support that will enhance functional tissue assembly in future applications. Mathematical modeling and numerical simulations will be used as relevant and suitable tools in the analysis of such interesting dynamics. They will be applied to introduce a rigorous framework for better recognition, definition and characterization of some specific links between the biomechanics and biochemistry of soft tissue on one side and the physicochemical features of the supporting environment on the other side, giving emphasis, in particular, to the effect of the fluid-dynamic shear stress (such attention being motivated by the recent experimental evidence that the shear stress exerted on the surface of a tissue specimen by an external moving fluid can induce changes in tissue metabolism and function). From a numerical-simulation standpoint, the student will be trained to use OpenFoam and other numerical codes available at the Department of Mechanical and Aerospace Engineering.
From a theoretical point of view, training will be provided with regard to 1) the general background (importance of this kind of research and potential practical applications), 2) governing parameters, 3) gravitational phenomena in multiphase flows, 4) Marangoni thermal effects, 5) Vibrational effects in multiphase systems, 6) Multiscale modeling, 8) Particle-tracking Numerical Methods. From a practical standpoint, the student will be trained to use available numerical tools. From an experimental standpoint, the student will be trained to investigate particle dynamics in different circumstances. It is expected that such a wide spectrum investigation will provide the student with the necessary skills to address in the future more complex problems of technological interest.
The opportunity is open to Home, EU and International applicants, who meet the required University of Strathclyde eligibility criteria. In particular, the applicant must not have been awarded a previous Doctoral Degree.
In addition to the above, the applicant will hold, or in the process of obtaining, an integrated Master’s degree or equivalent in Mechanical Engineering, Chemical Engineering, Materials Science, Aeronautical or Aerospace Engineering, Physics, or another discipline related to the proposed research projects.
Experience with OpenFoam or Ansys Fluent will be appreciated (but is not strictly required).
 M. Lappa, (2003), “Organic tissues in rotating bioreactors: Fluid-mechanical aspects, dynamic growth models and morphological evolution”, Biotechnology & Bioengineering, 84 (5): 518-532.
 M. Lappa, (2004), “A CFD Level-Set method for soft tissue growth: theory and fundamental equations”, Journal of Biomechanics, 38/1: 185-190.
This project is unfunded, and therefore would be suitable to eligible applicants with self funding, or with the possibility of other sources of funding. However, funding may be available for Home (UK) students who meet the requirements to be selected in the framework of the "Doctoral Training Partnership" of the University of Strathclyde with Engineering and Physical Sciences Research Council (EPSRC)