Characterization of the Functional Properties of Pcl Bone Scaffolds Fabricated Using Pneumatic Microextrusion

Author(s):  
Mohan Yu ◽  
Ye Jien Yeow ◽  
Logan Lawrence ◽  
Pier Paolo Claudio ◽  
James B. Day ◽  
...  

Abstract Pneumatic micro-extrusion (PME) is a direct-write additive manufacturing process, which has emerged as a robust, high-resolution method for the fabrication of a broad spectrum of biological tissues and organs. PME allows for non-contact multi-material deposition of functional inks for tissue engineering applications. In spite of the advantages and engendered potential applications, the PME process is inherently complex, governed by not only complex physical phenomena, but also material-process interactions. Consequently, investigation of the influence of PME process parameters as well as the underlying physical phenomena behind material transport and deposition in PME would be inevitably a need. The overarching goal of this research work is to fabricate biocompatible, porous bone tissue scaffolds for the treatment of osseous fractures, defects, and diseases. In pursuit of this goal, the objectives of the work are: (i) to investigate the influence of seven consequential scaffold design factors and PME process parameters on the mechanical properties of fabricated bone tissue scaffolds; (ii) to explore the underlying dynamics behind material transport in the PME process, using a 3D computational fluid dynamics (CFD) model. To investigate the effects of the design and process parameters, a series of experiments were designed and conducted. Layer height was identified as the most significant factor in this study. An increase in the layer height led to less overlap between subsequent layers, which allowed for more shrinkage and ultimately a reduction in scaffold diameter. In addition, print speed appeared as an influential factor in this study. An increase in the print speed resulted in a decline in linear mass density and thus in the extent of fusion between subsequent deposited layers. Besides, it was observed that there was a strong correlation between deposition mass and compression modulus. Overall, the results of this study pave the way for future investigation of PME-deposited PCL scaffolds with optimal functional and medical properties for incorporation of stem cells toward the treatment of osseous fractures and defects.

Author(s):  
Mohan Yu ◽  
Logan Lawrence ◽  
Pier Paolo Claudio ◽  
James B. Day ◽  
Roozbeh (Ross) Salary

Abstract Pneumatic micro-extrusion (PME), a direct-write additive manufacturing process, has emerged as a high-resolution method for the fabrication of a broad range of biological tissues and organs. However, the PME process is intrinsically complex, governed by complex physical phenomena. Hence, investigation of the effects of consequential parameters would be an inevitable need. The goal of this research work is to fabricate biocompatible, porous bone tissue scaffolds for the treatment of osseous fractures, defects, and eventually diseases. In pursuit of this goal, the objective of this study is to investigate the influence of material deposition factors — i.e., (i) deposition head temperature, (ii) flow pressure, and (iii) infill pattern — on the mechanical performance of PME-fabricated bone scaffolds. It was observed that the deposition head temperature as well as the flow pressure significantly affected scaffold diameter (unlike scaffold height). In addition, material deposition rate increased significantly as a result of an increase in the deposition temperature; this phenomenon stems from a reduction in Polycaprolactone (PCL) viscosity. Furthermore, there was a direct correlation between the amount of deposited mass and scaffold stiffness. Overall, the results of this study pave the way for future investigation of PME-deposited PCL scaffolds with optimal functional properties for incorporation of stem cells toward the treatment of osseous fractures and defects.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 647
Author(s):  
Mohamed Saiful Firdaus Hussin ◽  
Aludin Mohd Serah ◽  
Khairul Azri Azlan ◽  
Hasan Zuhudi Abdullah ◽  
Maizlinda Izwana Idris ◽  
...  

Collecting information from previous investigations and expressing it in a scientometrics study can be a priceless guide to getting a complete overview of a specific research area. The aim of this study is to explore the interrelated connection between alginate, gelatine, and hydroxyapatite within the scope of bone tissue and scaffold. A review of traditional literature with data mining procedures using bibliometric analyses was considered to identify the evolution of the selected research area between 2009 and 2019. Bibliometric methods and knowledge visualization technologies were implemented to investigate diverse publications based on the following indicators: year of publication, document type, language, country, institution, author, journal, keyword, and number of citations. An analysis using a bibliometric study found that 7446 papers were located with the keywords “bone tissue” and “scaffold”, and 1767 (alginate), 185 (gelatine), 5658 (hydroxyapatite) papers with those specific sub keywords. The number of publications that relate to “tissue engineering” and bone more than doubled between 2009 (1352) and 2019 (2839). China, the United States and India are the most productive countries, while Sichuan University and the Chinese Academy of Science from China are the most important institutions related to bone tissue scaffold. Materials Science and Engineering C is the most productive journal, followed by the Journal of Biomedical Materials Research Part A. This paper is a starting point, providing the first bibliometric analysis study of bone tissue and scaffold considering alginate, gelatine and hydroxyapatite. A bibliometric analysis would greatly assist in giving a scientific insight to support desired future research work, not only associated with bone tissue engineering applications. It is expected that the analysis of alginate, gelatine and hydroxyapatite in terms of 3D bioprinting, clinical outcomes, scaffold architecture, and the regenerative medicine approach will enhance the research into bone tissue engineering in the near future. Continued studies into these research fields are highly recommended.


2017 ◽  
Vol 62 (3) ◽  
pp. 1803-1812 ◽  
Author(s):  
K. Shunmugesh ◽  
K. Panneerselvam

AbstractCarbon Fiber Reinforced Polymer (CFRP) is the most preferred composite material due to its high strength, high modulus, corrosion resistance and rigidity and which has wide applications in aerospace engineering, automobile sector, sports instrumentation, light trucks, airframes. This paper is an attempt to carry out drilling experiments as per Taguchi’s L27(313) orthogonal array on CFRP under dry condition with three different drill bit type (HSS, TiAlN and TiN). In this research work Response Surface Analysis (RSA) is used to correlate the effect of process parameters (cutting speed and feed rate) on thrust force, torque, vibration and surface roughness. This paper also focuses on determining the optimum combination of input process parameter and the drill bit type that produces quality holes in CFRP composite laminate using Multi-objective Taguchi technique and TOPSIS. The percentage of contribution, influence of process parameters and adequacy of the second order regression model is carried out by analysis of variance (ANOVA). The results of experimental investigation demonstrates that feed rate is the pre-dominate factor which affects the response variables.


2020 ◽  
Vol 44 (4) ◽  
pp. 295-300
Author(s):  
Sanjay Kumar ◽  
Ashish Kumar Srivastava ◽  
Rakesh Kumar Singh

Friction stir processing is an avant-garde technique of producing new surface composite or changing the different properties of a material through intense, solid-state localized material plastic deformation. This change in properties depends upon the deformation formed by inserting a non-consumable revolving tool into the workpiece and travels laterally through the workpiece. This research work highlights the effect of process parameters on mechanical properties of fabricated surface composites by friction stir processing. By using various reinforcing materials like Ti, SiC, B4C, Al2O3 with waste elements like waste eggshells, rice husks, coconut shell and coir will be used to fabricate the green composites which are environmentally friendly and reduces the problem of decomposition. The parameter for this experiment is considered as the reinforcing materials, tool rotation speed and tool tilt angle. The SiC/Al2O3/Ti along with eggshell are selected asreinforcement materials. The main effect of the reinforcement is to improve mechanical properties, like hardness, impact strength and strength. The results revealed that the process parameters significantly affect the mechanical properties of friction stir processed surface composites.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Shishu Huang ◽  
Nuanyi Liang ◽  
Yang Hu ◽  
Xin Zhou ◽  
Noureddine Abidi

Polydopamine (PDA) prepared in the form of a layer of polymerized dopamine (DA) in a weak alkaline solution has been used as a versatile biomimetic surface modifier as well as a broadly used immobilizing macromolecule. This review mainly discusses the progress of biomaterial surface modification inspired by the participation of PDA in bone tissue engineering. A comparison between PDA-assisted coating techniques and traditional surface modification applied to bone tissue engineering is first presented. Secondly, the chemical composition and the underlying formation mechanism of PDA coating layer as a unique surface modifier are interpreted and discussed. Furthermore, several typical examples are provided to evidence the importance of PDA-assisted coating techniques in the construction of bone biosubstitutes and the improvement of material biocompatibility. Nowadays, the application of PDA as a superior surface modifier in multifunctional biomaterials is drawing tremendous interests in bone tissue scaffolds to promote the osteointegration for bone regeneration.


2012 ◽  
Vol 7 (4) ◽  
pp. 275-285 ◽  
Author(s):  
T.F. Pereira ◽  
M.A.C. Silva ◽  
M.F. Oliveira ◽  
I.A. Maia ◽  
J.V.L. Silva ◽  
...  

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