In silico biology of bone modelling and remodelling: regeneration

2009 ◽  
Vol 367 (1895) ◽  
pp. 2031-2053 ◽  
Author(s):  
L. Geris ◽  
J. Vander Sloten ◽  
H. Van Oosterwyck
Keyword(s):  
Mathematical Models ◽  
Experimental Research ◽  
In Silico ◽  
Healing Process ◽  
Treatment Strategies ◽  
Added Value ◽  
Mechanical Stimuli ◽  
Implant Placement ◽  
Bone Modelling ◽  
In Silico Biology

Bone regeneration is the process whereby bone is able to (scarlessly) repair itself from trauma, such as fractures or implant placement. Despite extensive experimental research, many of the mechanisms involved still remain to be elucidated. Over the last decade, many mathematical models have been established to investigate the regeneration process in silico . The first models considered only the influence of the mechanical environment as a regulator of the healing process. These models were followed by the development of bioregulatory models where mechanics was neglected and regeneration was regulated only by biological stimuli such as growth factors. The most recent mathematical models couple the influences of both biological and mechanical stimuli. Examples are given to illustrate the added value of mathematical regeneration research, specifically in the in silico design of treatment strategies for non-unions. Drawbacks of the current continuum-type models, together with possible solutions in extending the models towards other time and length scales are discussed. Finally, the demands for dedicated and more quantitative experimental research are presented.

In silico design of treatment strategies in wound healing and bone fracture healing

2010 ◽  
Vol 368 (1920) ◽  
pp. 2683-2706 ◽  
Author(s):  
L. Geris ◽  
R. Schugart ◽  
H. Van Oosterwyck
Keyword(s):  
Mathematical Models ◽  
Fracture Healing ◽  
Bone Fracture ◽  
In Silico ◽  
Healing Process ◽  
Treatment Strategies ◽  
Experimental Models ◽  
Bone Fracture Healing ◽  
Impaired Healing ◽  
Healing Processes

Wound and bone fracture healing are natural repair processes initiated by trauma. Over the last decade, many mathematical models have been established to investigate the healing processes in silico , in addition to ongoing experimental work. In recent days, the focus of the mathematical models has shifted from simulation of the healing process towards simulation of the impaired healing process and the in silico design of treatment strategies. This review describes the most important causes of failure of the wound and bone fracture healing processes and the experimental models and methods used to investigate and treat these impaired healing cases. Furthermore, the mathematical models that are described address these impaired healing cases and investigate various therapeutic scenarios in silico . Examples are provided to illustrate the potential of these in silico experiments. Finally, limitations of the models and the need for and ability of these models to capture patient specificity and variability are discussed.

DIFFRACTION ANALYSIS OF DEFORMED METALS: Theory, Methods, Programs

2019 ◽  
Author(s):  
Faina Satdarova
Keyword(s):  
Experimental Design ◽  
Dislocation Density ◽  
Mathematical Models ◽  
Diffraction Analysis ◽  
Experimental Research ◽  
Russian Federation ◽  
Statistical Estimation ◽  
X Rays ◽  
National University ◽  
The Russian Federation

General analysis of the distribution of crystals orientation and dislocation density in the polycrystalline system is presented. Recovered information in diffraction of X-rays adopting is new to structure states of polycrystal. Shear phase transformations in metals — at the macroscopic and microscopic levels — become a clear process. Visualizing the advances is produced by program included in package delivered. Mathematical models developing, experimental design, optimal statistical estimation, simulation the system under study and evolution process on loading serves as instrumentation. To reduce advanced methods to research and studies problem-oriented software will promote when installed. Automation programs passed a testing in the National University of Science and Technology “MISIS” (The Russian Federation, Moscow). You score an advantage in theoretical and experimental research in the field of physics of metals.

scholarly journals Initial mechanical conditions within an optimized bone scaffold do not ensure bone regeneration – an in silico analysis

2021 ◽  
Author(s):  
Camille Perier-Metz ◽  
Georg N. Duda ◽  
Sara Checa
Keyword(s):  
Bone Regeneration ◽  
In Silico ◽  
Volume Fraction ◽  
Computer Modelling ◽  
Mechanical Strain ◽  
In Silico Analysis ◽  
Bone Volume ◽  
Mechanical Stimuli ◽  
Design Strategies ◽  
Scaffold Design

AbstractLarge bone defects remain a clinical challenge because they do not heal spontaneously. 3-D printed scaffolds are a promising treatment option for such critical defects. Recent scaffold design strategies have made use of computer modelling techniques to optimize scaffold design. In particular, scaffold geometries have been optimized to avoid mechanical failure and recently also to provide a distinct mechanical stimulation to cells within the scaffold pores. This way, mechanical strain levels are optimized to favour the bone tissue formation. However, bone regeneration is a highly dynamic process where the mechanical conditions immediately after surgery might not ensure optimal regeneration throughout healing. Here, we investigated in silico whether scaffolds presenting optimal mechanical conditions for bone regeneration immediately after surgery also present an optimal design for the full regeneration process. A computer framework, combining an automatic parametric scaffold design generation with a mechano-biological bone regeneration model, was developed to predict the level of regenerated bone volume for a large range of scaffold designs and to compare it with the scaffold pore volume fraction under favourable mechanical stimuli immediately after surgery. We found that many scaffold designs could be considered as highly beneficial for bone healing immediately after surgery; however, most of them did not show optimal bone formation in later regenerative phases. This study allowed to gain a more thorough understanding of the effect of scaffold geometry changes on bone regeneration and how to maximize regenerated bone volume in the long term.

TOWARD IN SILICO BIOLOGY (FROM SEQUENCES TO SYSTEMS)

2008 ◽  
Author(s):  
ICHIRO YAMATO ◽  
TADASHI ANDO ◽  
AYUMI SUZUKI ◽  
KAZUO HARADA ◽  
SEIGO ITOH ◽  
...  
Keyword(s):  
In Silico ◽  
In Silico Biology

Experimental Research to Evaluate Thermal Behavior of a Brushless Driving Servomotor for Linear Motion NC Axis Experimental Stand

2015 ◽  
Vol 762 ◽  
pp. 55-60
Author(s):  
Georgia Cezara Avram ◽  
Florin Adrian Nicolescu ◽  
Radu Constantin Parpală ◽  
Constantin Dumitrascu
Keyword(s):  
Thermal Behavior ◽  
Mathematical Models ◽  
Experimental Research ◽  
Infrared Imaging ◽  
Experimental Results ◽  
Ball Screw ◽  
Linear Motion ◽  
Functional Optimization ◽  
Thermal Infrared Imaging ◽  
Experimental Stand

This paper presents the works carried out by the authors in the field of structural and functional optimization of industrial robot's numerically controlled (NC) axes. The study includes the results obtained in the research stage of the experimental measurements performed to evaluate the electrical servomotor's thermal behavior using a thermal (infrared) imaging camera. The analyzed servomotor is a brushless servomotor integrated in an experimental stand for linear motion NC axis experimental research, existing in the MMS department from EMTS faculty. Supplementary to the driving servomotor, the experimental stand includes a belt drive transmission, a ball screw - bearings assembly and a driven element guided by ball rail system. This experimental research phase is part of the doctoral thesis of first author and was conducted in order to validate the mathematical models developed in the PhD thesis. Thus, experimental results presented in the paper have been used to validate first mathematical models for electric motor's preliminary selection and checking, (performed by determining the total reflected inertia of the mechanical system on motor shaft level) as well as the mathematical models for final selection and checking (by evaluating the servomotor's thermal energy dissipation, and servomotor's internal and external maximum operating temperature). Second, the experimental results have been used to validate the assisted simulation for structural and functional optimization of industrial robot's NC axes based on both servomotor and drive's thermal behavior analysis, performed in the thesis by means of a dedicated commercial software package.

Methods for In Silico Biology: Model Construction and Analysis

2011 ◽  
pp. 7-36
Author(s):  
Theresa Yuraszeck ◽  
Peter Chang ◽  
Kalyan Gayen ◽  
Eric Kwei ◽  
Henry Mirsky ◽  
...  
Keyword(s):  
In Silico ◽  
Model Construction ◽  
In Silico Biology

scholarly journals Computational modeling of human bone fracture healing affected by different conditions of initial healing stage

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Mohammad S. Ghiasi ◽  
Jason E. Chen ◽  
Edward K. Rodriguez ◽  
Ashkan Vaziri ◽  
Ara Nazarian
Keyword(s):  
Bone Healing ◽  
Granulation Tissue ◽  
Initial Phase ◽  
Callus Formation ◽  
Healing Process ◽  
Treatment Strategies ◽  
Healing Time ◽  
Design And Optimization ◽  
Healing Phase ◽  
Secondary Bone Healing

Abstract Background Bone healing process includes four phases: inflammatory response, soft callus formation, hard callus development, and remodeling. Mechanobiological models have been used to investigate the role of various mechanical and biological factors on bone healing. However, the effects of initial healing phase, which includes the inflammatory stage, the granulation tissue formation, and the initial callus formation during the first few days post-fracture, are generally neglected in such studies. Methods In this study, we developed a finite-element-based model to simulate different levels of diffusion coefficient for mesenchymal stem cell (MSC) migration, Young’s modulus of granulation tissue, callus thickness and interfragmentary gap size to understand the modulatory effects of these initial phase parameters on bone healing. Results The results quantified how faster MSC migration, stiffer granulation tissue, thicker callus, and smaller interfragmentary gap enhanced healing to some extent. However, after a certain threshold, a state of saturation was reached for MSC migration rate, granulation tissue stiffness, and callus thickness. Therefore, a parametric study was performed to verify that the callus formed at the initial phase, in agreement with experimental observations, has an ideal range of geometry and material properties to have the most efficient healing time. Conclusions Findings from this paper quantified the effects of the initial healing phase on healing outcome to better understand the biological and mechanobiological mechanisms and their utilization in the design and optimization of treatment strategies. It is also demonstrated through a simulation that for fractures, where bone segments are in close proximity, callus development is not required. This finding is consistent with the concepts of primary and secondary bone healing.

A 3d Histomorphometric Method for Analyses of Skeletal Tissue Mechanobiology

2007 ◽  
Author(s):  
Ryan E. Gleason ◽  
Kristy T. S. Palomares ◽  
Thomas A. Einhorn ◽  
Louis C. Gerstenfeld ◽  
Elise F. Morgan
Keyword(s):  
Healing Process ◽  
Fracture Site ◽  
Cartilage Tissue ◽  
In Vivo Model ◽  
Original Form ◽  
Mechanical Stimuli ◽  
Fracture Callus ◽  
Skeletal Tissue ◽  
Form And Function

Skeletal repair and regeneration involve a dynamic interplay of biological processes that result in spatially and temporally varying patterns of tissue formation and remodeling. For example, during bone fracture healing the cartilaginous callus that is formed initially in the fracture site is subsequently mineralized and remodeled to restore the original form and function to the injured bone. During much of this healing process, the fracture callus is comprised of a heterogeneous mixture of cartilage, fibrocartilage, multipotent mesenchymal tissue, and bone. Adding to this complexity, mechanical stimuli are known to influence the rate and type of tissues formed during skeletal healing [1]. Given the growing body of evidence that controlled mechanical stimulation may be used to enhance healing, it is of substantial interest to elucidate relationships between the distributions of local stresses and strains that develop within the healing region and the distribution of tissue types that form. While histomorphometry is a well established approach for characterizing the latter, it has historically been limited to analyses of a small number of two-dimensional sections of tissue. Such 2D sampling may be inadequate for quantitative characterization of the irregular geometry and heterogeneous composition of healing tissues. In this study, we report on a 3D histomorphometric method and apply this method to an in vivo model of skeletal repair [2] in which a bending stimulus delivered to a healing bone defect results in the formation of predominantly cartilage tissue, rather than bone.

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