Connie Gomez

Computer-aided tissue engineering: application to biomimetic modelling and design of tissue scaffolds

Computer‐aided tissue engineering (CATE) enables many novel approaches in modelling, design and fabrication of complex tissue substitutes with enhanced functionality and improved cell–matrix interactions. Central to CATE is its bio‐tissue informatics model that represents tissue biological, biomechanical and biochemical information that serves as a central repository to interface design, simulation and tissue fabrication. The present paper discusses the application of a CATE approach to the biomimetic design of bone tissue scaffold. A general CATE‐based process for biomimetic modelling, anatomic reconstruction, computer‐assisted‐design of tissue scaffold, quantitative‐computed‐tomography characterization, finite element analysis and freeform extruding deposition for fabrication of scaffold is presented.

Image-based biomimetic modeling and its application in computer-aided tissue engineering

High resolution SEM, light microscopy, and non-invasive CT/MRI imaging can produce 3D views of anatomy and generate computational tissue models for many biomedical and tissue engineering applications. Recently, the integration of image processing with computer-aided design (CAD), computer aided manufacturing (CAM), and solid freeform fabrication technology has achieved a remarkable advance in the field of computer-aided tissue engineering (CATE). This paper presents an overview of CATE, including its application in computer-aided tissue modeling, computer-aided tissue informatics, and computer-aided tissue scaffold design and manufacturing. An image-based 3D reconstruction approach, along with a discussion of various enabling reverse engineering techniques for structural representation and CAD based modeling of tissue anatomy will be introduced. An example of biomimetic modeling and design of 3D heterogeneous bony tissue structures under anatomical, biological, and mechanical constraints will also be presented.

Computer-aided bone scaffold design: a biomimetic approach

The design of 3D tissue scaffolds for tissue engineering application should, if possible, biomimic the complex hierarchy and structural heterogeneity of the replaced tissues. This is particularly true for the design of bone tissue replacement with matched spatial heterogeneity and mechanical properties to the replaced bone. This paper presents an image-based computer modeling approach for reconstruction, characterization, and biomimetic modeling and design of three-dimensional bone tissue replacement, including the outline of biomimetic modeling approach, reconstruction to CAD-based tissue anatomic representation, and the design and characterization of bone replacement.

Unit-Cell Based Design and Modeling in Tissue Engineering Applications

AbstractThis work makes a three-fold contribution for a unit-cell based methodology for designing tissue scaffolds. We present a study on unit-cell informatics; we also propose computational methods to characterize unit-cells, and finally we develop criteria for connectivity between unit-cells. We will define a set of unit-cell parameters relevant for the geometrical, structural, mechanical, transport, and biological properties in tissue engineering applications. We will also present computation and engineering based approaches to evaluate unit-cell properties. We will also develop a combinatorial framework to study the unit-cell topological connectivity and scaffold properties. Using this information, we will be able to design an interconnected 3D porous scaffold to meet application requirements.

Tissue engineered constructs: connectivity study for three dimensional two-phase structures

Porous three-dimensional (3D) tissue scaffolds play an important role in cell attachment, proliferation, and guidance of new tissue formation. Performance of engineered heterogeneous tissues depends on porous scaffold microstructures with specific porosity characteristics. This paper presents our recent study on establishing topological connectivity criteria for surface matching between designed tissue scaffolds for freeform fabrication and for the insurance of suitable connections creation for scaffold flow and mass transport. To provide a structural and/or contour connectivity between surfaces, the concept of many-to-many matching of skeletal representations is adopted. The matching algorithm is based on the metric-tree encoding of surface skeletal representations, their low-distortion embeddings into normed vector spaces, and the Earth Movers Distance under transformation.

Data Exchange for Unit-Cell Based Tissue Scaffold Design, Analysis and Fabrication

Tissue scaffolds must satisfy multiple design constraints, such as geometry, mechanical properties, and connectivity, to yield a functioning heterogeneous tissue. Onemethod that accounts for these multiple constraints is the unit-cellbased assembly approach. In this method, the volume that represents the natural tissue is filled with unit-cells that meet thedesign requirements of the volume. This approach requires data exchanges between several procedures including design, characterization, assembly, analysis, and fabrication procedures. In the paper, we present a data exchange system to store andretrieve the unit-cell information and customize data migrationamong applications. We also present our application of this dataexchange system to facilitate the management of data flow.

Multi - Parameter Optimization for Two-Phase Unit-Cell based Tissue Scaffolds

Porous three-dimensional (3D) tissue scaffolds directly influence cell attachment, proliferation, and guidance of new tissue formation. Cells respond to a scaffolds architecture, mechanical properties, and transport properties. Given the number of design constraints, scaffold design must include multiple design parameters. Using a unit-cell based assembly approach, we introduce a method to account for multiple design parameters during scaffold assembly. This paper presents our method for integrating multiple parameters for unit-cell selection.

Connectivity for mass and fluid transport in three dimensional two-phase structures

Porous three-dimensional (3D) tissue scaffolds provide vital function for cell attachment, proliferation, and guidance of new tissue formation. In the cellular tissue engineering process, heterogeneous tissue scaffolds play an important role in heterogeneous tissue formation. The goal of this research is to develop an approach that will assemble characterized unit cell structures into a larger heterogeneous scaffold that is suitable for tissue regrowth. To construct the assembly, 3D skeletons are first generated for unit cell structures, and for every skeleton point, the physical properties and quantities under given flow conditions are assigned. A unit cell alignment approach then quantifies the matching potential between two 3D skeletons. Based on the priority of the physical properties that were ranked prior to the assembly process, unit cells are assembled into a larger scaffold in a bottom-up fashion.

On effective properties of heterogeneous bone scaffold

Scaffold material, porosity and internal pore architecture are essential parameters for bone scaffold design that affect both scaffold function and cell-tissue ingrowth. A general approach for design of bone scaffold is to mimic natural tissue properties, namely, the tissue heterogeneity and anisotropy. This paper presents a modified multi-cell model that can be used to predict the effective properties of heterogeneous bone scaffolds with an improved accuracy. Results from the model prediction are reported.