Modeling of porous structures for rapid prototyping of tissue engineering scaffolds

2007 ◽  
Vol 39 (5-6) ◽  
pp. 501-511 ◽  
Author(s):  
Antonio Armillotta ◽  
Ralph Pelzer
Keyword(s):  
Tissue Engineering ◽  
Rapid Prototyping ◽  
Porous Structures ◽  
Tissue Engineering Scaffolds

scholarly journals GAKTpore: Stereological Characterisation Methods for Porous Foams in Biomedical Applications

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1269
Author(s):  
Gareth Sheppard ◽  
Karl Tassenberg ◽  
Bogdan Nenchev ◽  
Joel Strickland ◽  
Ramy Mesalam ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Biomedical Applications ◽  
Large Scale ◽  
Collagen Scaffold ◽  
Porous Structures ◽  
Tissue Engineering Scaffolds ◽  
Biological Responses ◽  
Sem Micrograph ◽  
Cell Adhesion And Proliferation ◽  
Characterisation Methods

In tissue engineering, scaffolds are a key component that possess a highly elaborate pore structure. Careful characterisation of such porous structures enables the prediction of a variety of large-scale biological responses. In this work, a rapid, efficient, and accurate methodology for 2D bulk porous structure analysis is proposed. The algorithm, “GAKTpore”, creates a morphology map allowing quantification and visualisation of spatial feature variation. The software achieves 99.6% and 99.1% mean accuracy for pore diameter and shape factor identification, respectively. There are two main algorithm novelties within this work: (1) feature-dependant homogeneity map; (2) a new waviness function providing insights into the convexity/concavity of pores, important for understanding the influence on cell adhesion and proliferation. The algorithm is applied to foam structures, providing a full characterisation of a 10 mm diameter SEM micrograph (14,784 × 14,915 px) with 190,249 pores in ~9 min and has elucidated new insights into collagen scaffold formation by relating microstructural formation to the bulk formation environment. This novel porosity characterisation algorithm demonstrates its versatility, where accuracy, repeatability, and time are paramount. Thus, GAKTpore offers enormous potential to optimise and enhance scaffolds within tissue engineering.

scholarly journals THREE-DIMENSIONAL NANOCOMPOSITE SCAFFOLDS FOR BONE TISSUE ENGINEERING: FROM DESIGN TO APPLICATION

Nano LIFE ◽  
2012 ◽  
Vol 02 (01) ◽  
pp. 1250005 ◽  
Author(s):  
BIN DUAN ◽  
MIN WANG ◽  
WILLIAM W. LU
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Rabbit Model ◽  
Bone Morphogenetic Protein 2 ◽  
Human Umbilical Cord ◽  
Porous Structures ◽  
Tissue Engineering Scaffolds ◽  
Surface Modified ◽  
Nanocomposite Scaffolds

Selective laser sintering (SLS), a rapid prototyping technology, was investigated for producing bone tissue engineering scaffolds. Completely biodegradable osteoconductive calcium phosphate (Ca-P)/poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) scaffolds were successfully fabricated via SLS using Ca-P/PHBV nanocomposite microspheres. In the SLS manufacturing route, the architecture of tissue engineering scaffolds (pore shape, size, interconnectivity, etc.) can be designed and the sintering process can be optimized for obtaining scaffolds with desirable porous structures and mechanical properties. SLS was also shown to be very effective in producing highly complex porous structures using nanocomposite microspheres. To render SLS-formed Ca-P/PHBV scaffolds osteoinductive, recombinant human bone morphogenetic protein-2 (rhBMP-2) could be loaded onto the scaffolds. For achieving a controlled release of rhBMP-2 from scaffolds, surface modification of Ca-P/PHBV scaffolds by gelatin entrapment and heparin immobilization was needed. The immobilized heparin provided binding affinity for rhBMP-2. Surface modified Ca-P/PHBV nanocomposite scaffolds loaded with rhBMP-2 enhanced the proliferation of human umbilical cord derived mesenchymal stem cells (hUCMSCs) and also their alkaline phosphatase activity. In in vivo experiments using a rabbit model, surface modified Ca-P/PHBV nanocomposite scaffolds loaded with rhBMP-2 promoted ectopic bone formation, exhibiting their osteoinductivity. The strategy of combining advanced scaffold fabrication, nanocomposite material, and controlled growth factor delivery is promising for bone tissue regeneration.

scholarly journals Triblock Copolymers Based on ε-Caprolactone and Trimethylene Carbonate for the 3D Printing of Tissue Engineering Scaffolds

2017 ◽  
Vol 40 (4) ◽  
pp. 176-184 ◽  
Author(s):  
Aysun Güney ◽  
Jos Malda ◽  
Wouter J.A. Dhert ◽  
Dirk W. Grijpma
Keyword(s):  
Tissue Engineering ◽  
Glass Transition ◽  
3D Printing ◽  
Melting Temperature ◽  
Triblock Copolymers ◽  
Ethylene Carbonate ◽  
Porous Structures ◽  
Trimethylene Carbonate ◽  
Tissue Engineering Scaffolds ◽  
Slow Cooling

Background Biodegradable PCL- b-PTMC- b-PCL triblock copolymers based on trimethylene carbonate (TMC) and ε-caprolactone (CL) were prepared and used in the 3D printing of tissue engineering scaffolds. Triblock copolymers of various molecular weights containing equal amounts of TMC and CL were prepared. These block copolymers combine the low glass transition temperature of amorphous PTMC (approximately -20°C) and the semi-crystallinity of PCL (glass transition approximately -60°C and melting temperature approximately 60°C). Methods PCL- b-PTMC- b-PCL triblock copolymers were synthesized by sequential ring opening polymerization (ROP) of TMC and ε-CL. From these materials, films were prepared by solvent casting and porous structures were prepared by extrusion-based 3D printing. Results Films prepared from a polymer with a relatively high molecular weight of 62 kg/mol had a melting temperature of 58°C and showed tough and resilient behavior, with values of the elastic modulus, tensile strength and elongation at break of approximately 120 MPa, 16 MPa and 620%, respectively. Porous structures were prepared by 3D printing. Ethylene carbonate was used as a crystalizable and water-extractable solvent to prepare structures with microporous strands. Solutions, containing 25 wt% of the triblock copolymer, were extruded at 50°C then cooled at different temperatures. Slow cooling at room temperature resulted in pores with widths of 18 ± 6 μm and lengths of 221 ± 77 μm, rapid cooling with dry ice resulted in pores with widths of 13 ± 3 μm and lengths of 58 ± 12 μm. These PCL- b-PTMC- b-PCL triblock copolymers processed into porous structures at relatively low temperatures may find wide application as designed degradable tissue engineering scaffolds. Conclusions In this preliminary study we prepared biodegradable triblock copolymers based on 1,3-trimethylene carbonate and ε-caprolactone and assessed their physical characteristics. Furthermore, we evaluated their potential as melt-processable thermoplastic elastomeric biomaterials in 3D printing of tissue engineering scaffolds.

Fabrication of Photo-Polymerized PCL Tissue Engineering Scaffolds by Dynamic Masking Rapid Prototyping System

2013 ◽  
Vol 750 ◽  
pp. 125-129 ◽  
Author(s):  
Yih Lin Cheng ◽  
Chin Jen Hsueh ◽  
Su Hai Hsiang
Keyword(s):  
Tissue Engineering ◽  
Rapid Prototyping ◽  
Single Layer ◽  
Basic Element ◽  
Tissue Engineering Scaffolds ◽  
Great Opportunity ◽  
Design Concepts ◽  
Manufacturing Techniques ◽  
Rapid Prototyping System ◽  
Interconnected Pore

PCL is one of the popular biomaterials used in tissue engineering scaffolds, but it is seldom shaped by photo-polymerization. Layered manufacturing techniques, also known as Rapid Prototyping (RP) processes, provide a great opportunity to fabricate 3D scaffolds without problems such as limited control of pore-size and restricted geometric shapes in traditional methods. In our previous researches, the Biomedical Dynamic Masking Rapid Prototyping System was developed to photo-cure biodegradable materials through visible light. In this research, the Dynamic Masking RP System was modified to photo-polymerize cross-linkable PCL to form tissue engineering scaffolds. The cross-linkable PCL was synthesized by reacting PCL and acryloyl chloride, and dissolved in acetone mixing with photo-initiator. The tensile test and degradation test were performed on the cured PCL samples. Fabrication of single-layer pattern was first tested to understand the system’s capability and showed the errors were within 7%. Two types of scaffold design concepts were adopted—one took square, hexagon, or triangle as a basic element to create 2D grid patterns, and the interconnected pore were produced by offsetting the 2D pattern in alternating layers; the other took a double-sided trapezoid as a unit and arrayed it into tube shape with interconnected pore network. Various PCL porous tube scaffolds have been successfully fabricated in this study. In the future, they can be utilized to cell growth or mass cell duplication applications.

Design and Fabrication of Bone Tissue Engineering Scaffolds via Rapid Prototyping and CAD

2007 ◽  
Vol 25 ◽  
pp. 379-383 ◽  
Author(s):  
Lin Liulan ◽  
Hu Qingxi ◽  
Huang Xianxu ◽  
Xu Gaochun
Keyword(s):  
Tissue Engineering ◽  
Rapid Prototyping ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Tissue Engineering Scaffolds
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