Biomaterials, implants and tissue engineering

Biomechanics and mechanobiology

Dr. Noailly, Jérôme
Senior Research Associate


Torre I - Planta 10 | Baldiri Reixac, 4 | 08028 | Barcelona
Email : jnoaillyibecbarcelona.eu

Research Topics

Biomechanics (spine, lower limbs); Mutiphysics (cartilage, intervertebral disc, artery); Biophysics (intervertebral disc nutrition, cytokines); Computational analyses (finite element element, numerical optimisations, stochastic modelling); In vitro experiments (dynamic culture, tissue/biomaterial mechanical characterisation)


Research in the group of Biomechanics and Mechanobiology focuses mainly on (i) the interactions between tissue multiphysics and biological processes, and (ii) how these interactions can affect the functional biomechanics of organs. Numerical methods based mostly but not exclusively on FE modelling are used to describe both the tissues at the organ level, and the tissue-cell interactions at the tissue and cellular levels. The numerical concepts developed are tested against in vivo and in vitro data, which allows model validations. Emphasis is given in the study of load transfer of organ conditions onto the cells or onto tissues, with or without treatment simulations. Calculations are based on mechano-regulation and/or on biophysical concepts to predict different cell environments over time.

 

Displacement field computed in a finite element model of the lower lumbar spine (L3 to L5-S1 intervertebral disc) under the action of the active muscle fascicles in flexion

 

 

 

Most tissue and biophysical models developed so far aimed to study one of the most complex organs of the musculoskeletal system, namely the spine. Thorough knowledge about the functional biomechanics of the lumbar spine has been acquired along the time in relation to computational simulations (J Biomech, 40, 2414-25; Biomech Model Mechanobiol, 10, 203-19). To capture as best as possible the communications between organ and tissue biomechanics, studies of advanced tissue models has been performed, in relation to the vertebrae (Mater Lett, 78, 154-58), the intervertebral discs (J Mech Behav Biomed Mater, 4, 124-41; Comput Meth Biomech Biomed Engin, in press) and to the muscles (J Biomech, 45, S484). In particular, these models allowed thorough identification of the tissue parameters expected to alter cell nutrition in a deforming intervertebral disc (PLoS Comput Biol, 7, e1002112), leading to further relations between tissue condition and cell viability (J Tiss Eng Regen Med, 6, 389).

 

 

Cell viability predictions given by different mechanotransduction assumptions within a bovine intervertebral model subject to steady-state overloads

 

 

 

 

 

 

 

The numerical stability of these models is also one target of the explorations performed within the group (Biomaterials for spinal surgery, Part I, Chap 5, 144-232, Woodhead Publishing Ltd; J Biomech, 45, S600), in order to ensure the coupling to lower scale biophysical models. Also, models have been used to for implant simulations focussed either on clinical (J Appl Biomat Biomech, 4, 135-42), or on design questions (Eur Spine J, 21, S675-87). Beyond the spine domain, both knowledge and know-how acquired are being transferred to the exploration of the cardiovascular system, and ongoing clinical collaborations are contributing to the adaptation of the numerical methods to study problems related to the lower limbs (J Biomech, 45, S163).

Micro-modelling of the vertebral endplate

Left, principal stress predictions in a model of the human hip joint; right, generic model of the healthy lumbar spine (left), and specimen-specific model of a degenerated lumbar spine