Search results
21 – 30 of over 6000This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE…
Abstract
This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE) applications in different fields of biomechanics between 1976 and 1991. The aim of this paper is to help the users of FE and BE techniques to get better value from a large collection of papers on the subjects. Categories in biomechanics included in this survey are: orthopaedic mechanics, dental mechanics, cardiovascular mechanics, soft tissue mechanics, biological flow, impact injury, and other fields of applications. More than 900 references are listed.
Details
Keywords
To introduce recent research and development of biopolymer deposition for freeform fabrication of three‐dimensional tissue scaffolds that is capable of depositing bioactive…
Abstract
Purpose
To introduce recent research and development of biopolymer deposition for freeform fabrication of three‐dimensional tissue scaffolds that is capable of depositing bioactive ingredients.
Design/methodology/approach
A multi‐nozzle biopolymer deposition system is developed, which is capable of extruding biopolymer solutions and living cells for freeform construction of 3D tissue scaffolds. The deposition process is biocompatible and occurs at room temperature and low pressures to reduce damage to cells. In contrast with other systems, this system is capable of, simultaneously with scaffold construction, depositing controlled amount of cells, growth factors, or other bioactive compounds with precise spatial position to form complex cell‐seeded tissue constructs. The examples shown are based on sodium alginate solutions and poly‐ε‐caprolactone (PCL). Studies of the biopolymer deposition feasibility, structural formability, and different material deposition through a multi‐nozzle heterogeneous system are conducted and presented.
Findings
Provides information about the biopolymer deposition using different nozzle systems, the relations of process parameters on deposition flow rate and scaffold structural formability. Three‐dimensional alginate‐based scaffolds and scaffold embedded with living cells can be freeform constructed according to various design configurations at room temperature without using toxic materials.
Research limitations/implications
Other biopolymers may also be studied for structure formation. Studying cell viability and cellular tissue engineering behavior of the scaffolds after the cell deposition should be further investigated.
Practical implications
A very useful and effective tool for construction of bioactive scaffolds for tissue engineering applications based on a multi‐nozzle biopolymer deposition.
Originality/value
This paper describes a novel process and manufacturing system for fabrication of bioactive tissue scaffolds, automatic cell loading, and heterogeneous tissue constructs for emerging regenerative medicine.
Details
Keywords
Yihao Zheng, Yancheng Wang, Roland K. Chen, Sagar Deshpande, Noah S. Nelson, Steven R. Buchman and Albert J. Shih
To obtain a vascularized autologous bone graft by in-vivo tissue transformation, a biocompatible tissue transformation mold (TTM) is needed. An ideal TTM is of high geometric…
Abstract
Purpose
To obtain a vascularized autologous bone graft by in-vivo tissue transformation, a biocompatible tissue transformation mold (TTM) is needed. An ideal TTM is of high geometric accuracy and X-ray radiolucent for monitoring the bone tissue formation. The purpose of this study is to present the TTM design and fabrication process, using 3D reconstruction, stereolithography (SLA) and silicone molding.
Design/methodology/approach
The rat mandible, the targeted bone graft, was scanned by micro-computed tomography (CT). From the micro-CT images, the 3D mandible model was identified and used as the cavity geometry to design the TTM. The TTM was fabricated by molding the biocompatible and radiolucent silicone in the SLA molds. This TTM was implanted in a rat for in vivo tests on its biocompatibility and X-ray radiolucency.
Findings
SLA can fabricate the TTM with a cavity shape that accurately replicates that of the rat mandible. The bone formation inside of the silicone TTM can be observed by X-ray. The TTM is feasible for in vivo tissue transformation for vascularized bone reconstruction.
Research limitations/implications
Research of the dimensional and geometrical accuracy of the TTM cavity is required in the future study of this process.
Practical implications
The TTM fabricated in this presented approach has been used for in-vivo tissue transformation. This technique can be implemented for bone reconstruction.
Originality/value
The precision fabrication of the TTMs for in-vivo tissue transformation into autogenous vascularized bone grafts with complex structures was achieved by using SLA, micro-CT and silicone molding.
Details
Keywords
Alexander D. Klose and Andreas H. Hielscher
This paper sets out to give an overview about state‐of‐the‐art optical tomographic image reconstruction algorithms that are based on the equation of radiative transfer (ERT).
Abstract
Purpose
This paper sets out to give an overview about state‐of‐the‐art optical tomographic image reconstruction algorithms that are based on the equation of radiative transfer (ERT).
Design/methodology/approach
An objective function, which describes the discrepancy between measured and numerically predicted light intensity data on the tissue surface, is iteratively minimized to find the unknown spatial distribution of the optical parameters or sources. At each iteration step, the predicted partial current is calculated by a forward model for light propagation based on the ERT. The equation of radiative is solved with either finite difference or finite volume methods.
Findings
Tomographic reconstruction algorithms based on the ERT accurately recover the spatial distribution of optical tissue properties and light sources in biological tissue. These tissues either can have small geometries/large absorption coefficients, or can contain void‐like inclusions.
Originality/value
These image reconstruction methods can be employed in small animal imaging for monitoring blood oxygenation, in imaging of tumor growth, in molecular imaging of fluorescent and bioluminescent probes, in imaging of human finger joints for early diagnosis of rheumatoid arthritis, and in functional brain imaging.
Details
Keywords
Ramakrishna Vasireddi and Bikramjit Basu
The purpose of this paper is to investigate the possibility to construct tissue-engineered bone repair scaffolds with pore size distributions using rapid prototyping techniques…
Abstract
Purpose
The purpose of this paper is to investigate the possibility to construct tissue-engineered bone repair scaffolds with pore size distributions using rapid prototyping techniques.
Design/methodology/approach
The fabrication of porous scaffolds with complex porous architectures represents a major challenge in tissue engineering and the design aspects to mimic complex pore shape as well as spatial distribution of pore sizes of natural hard tissue remain unexplored. In this context, this work aims to evaluate the three-dimensional printing process to study its potential for scaffold fabrication as well as some innovative design of homogeneously porous or gradient porous scaffolds is described and such design has wider implication in the field of bone tissue engineering.
Findings
The present work discusses biomedically relevant various design strategies with spatial/radial gradient in pore sizes as well as with different pore sizes and with different pore geometries.
Originality/value
One of the important implications of the proposed novel design scheme would be the development of porous bioactive/biodegradable composites with gradient pore size, porosity, composition and with spatially distributed biochemical stimuli so that stem cells loaded into scaffolds would develop into complex tissues such as those at the bone–cartilage interface.
Details
Keywords
Nataraj Poomathi, Sunpreet Singh, Chander Prakash, Arjun Subramanian, Rahul Sahay, Amutha Cinappan and Seeram Ramakrishna
In the past decade, three-dimensional (3D) printing has gained attention in areas such as medicine, engineering, manufacturing art and most recently in education. In biomedical…
Abstract
Purpose
In the past decade, three-dimensional (3D) printing has gained attention in areas such as medicine, engineering, manufacturing art and most recently in education. In biomedical, the development of a wide range of biomaterials has catalysed the considerable role of 3D printing (3DP), where it functions as synthetic frameworks in the form of scaffolds, constructs or matrices. The purpose of this paper is to present the state-of-the-art literature coverage of 3DP applications in tissue engineering (such as customized scaffoldings and organs, and regenerative medicine).
Design/methodology/approach
This review focusses on various 3DP techniques and biomaterials for tissue engineering (TE) applications. The literature reviewed in the manuscript has been collected from various journal search engines including Google Scholar, Research Gate, Academia, PubMed, Scopus, EMBASE, Cochrane Library and Web of Science. The keywords that have been selected for the searches were 3 D printing, tissue engineering, scaffoldings, organs, regenerative medicine, biomaterials, standards, applications and future directions. Further, the sub-classifications of the keyword, wherever possible, have been used as sectioned/sub-sectioned in the manuscript.
Findings
3DP techniques have many applications in biomedical and TE (B-TE), as covered in the literature. Customized structures for B-TE applications are easy and cost-effective to manufacture through 3DP, whereas on many occasions, conventional technologies generally become incompatible. For this, this new class of manufacturing must be explored to further capabilities for many potential applications.
Originality/value
This review paper presents a comprehensive study of the various types of 3DP technologies in the light of their possible B-TE application as well as provides a future roadmap.
Details
Keywords
Li Wu, Xinxin Li, Tianmin Guan, Yong Chen and Chunwei Qi
The 3 D bioprinting technology is used to prepare the tissue engineering scaffold with precise structures for the cell proliferation and differentiation.
Abstract
Purpose
The 3 D bioprinting technology is used to prepare the tissue engineering scaffold with precise structures for the cell proliferation and differentiation.
Design/methodology/approach
According to the characteristics of the ideal tissue engineering scaffold, the microstructural design of the tissue engineering scaffold is carried out. The bioprinter is used to fabricate the tissue engineering scaffold with different structures and spacing sizes. Finally, the scaffold with good connectivity is achieved and used to cell PC12 culture.
Findings
The results show that the pore structure with the line spacing of 1 mm was the best for cell culture, and the survival rate of the inoculated cells PC12 is as high as 90%. The influence of the pore shape on the cell survival is not evidence.
Originality/value
This study shows that tissue engineering scaffolds prepared by 3 D bioprinting have graded structure for three-dimensional cell culture, which lays the foundation for the later detection of drug resistance.
Details
Keywords
Bruno Bisceglia, Francesca de Terlizzi, Antonio Scaglione and Nicola Francesco Tallarino
Electrochemotherapy (ECT) is an outstanding technique for treatment of tumor nodules which is currently used for treatment of skin metastases, and now it is being developed for…
Abstract
Purpose
Electrochemotherapy (ECT) is an outstanding technique for treatment of tumor nodules which is currently used for treatment of skin metastases, and now it is being developed for treatment of internal organs such as, bone, liver, etc. In this work the authors' goal was finding a simple and proper needles configuration, allowing electroporation of whole cancer cell membranes, possibly minimizing direct cell death of healthy tissue.
Design/methodology/approach
This work shows numerical analysis of the ECT of a deep-seated tumor, like in bone tissue of human limb. The tumor is excited by a sequence of square-wave electric pulses (5 kHz), inducing a 1,000 V/cm electric field through a suitable configuration of 30 mm long steel needle electrodes inserted in a part of limb long 20 cm. Treated element is numerically modeled in a very simplified 3D geometry. All materials are assumed as homogeneous, linear and isotropic mediums.
Findings
Electrochemotherapy is based on the local application of short and intense electric pulses that transiently permeabilizes neoplastic cells membrane, thus allowing cytotoxicity increase of a chemotherapeutic drug, bleomycin, and reducing its dosage. The local field in target tissues depends on geometry and position of electrodes, that have to be placed according cancer shape and size, and excited by electric pulses of opportune amplitude. Current efforts are aimed to test whether electric pulses can be applied to bone through invasive needles without affecting the recovery of osteogenetic activity.
Originality/value
The results of the simulation study can help to establish the appropriate geometric and electric setup for treatment of bone metastases in clinical ECT trials. This paper reports results from different needles configurations and show that a proper needle positioning allows complete electroporation of the whole tumor
.
Details
Keywords
Dejan B. Jovanovic, Dragan Krasic, Nenad N. Cvetkovic, Dragan Vuckovic and Vladimir B. Stanković
The purpose of this paper is to determine the electric field and specific absorption rate (SAR) distribution within biological tissues in the vicinity of dental implants, exposed…
Abstract
Purpose
The purpose of this paper is to determine the electric field and specific absorption rate (SAR) distribution within biological tissues in the vicinity of dental implants, exposed to the mobile phone radiation.
Design/methodology/approach
This research was performed for the frequency of 2.6 GHz, which corresponds to 4G mobile network. The adequate 3D realistic numerical models of the mobile phone user’s head, dental implants and actual smartphone model are created using packages based on the finite integral technique numerical method.
Findings
The obtained results yield to a conclusion that the presence of dental implants affects the increase in electric field intensity and SAR values within biological tissues in its vicinity.
Research limitations/implications
The presented procedure is limited to the 4G mobile network frequency of 2.6 MHz. The study should be extended to other mobile network frequencies to be more general.
Practical implications
The criteria for selection of the materials used for dental implants production should be extended with the recommended material characteristics related to their influence on the electric field and SAR distribution, to keep their values in the limits prescribed by standards.
Social implications
The obtained results provide the foundation for future research in mobile devices’ electromagnetic fields’ influence on human health.
Originality/value
The accurate determination of the electric field and SAR values within different biological tissues and organs in the vicinity of dental implants exposed to mobile phone electromagnetic radiation, demands highly realistic model of observed biological structures. For purposes of the current study, the procedure for modeling of highly nonhomogeneous structure with finite number of homogenous domains having known electromagnetic parameters is described in the paper. As a result, the 3D complex users’ head model formed of 16 homogeneous domains of different electromagnetic parameters is created.
Details
Keywords
Adib Bin Rashid, Abu Saleh Md. Nakib Uddin, Fahima Akter Azrin, Khondker Safin Kaosar Saad and Md Enamul Hoque
The main objective of this paper is to illustrate an analytical view of different methods of 3D bioprinting, variations, formulations and characteristics of biomaterials. This…
Abstract
Purpose
The main objective of this paper is to illustrate an analytical view of different methods of 3D bioprinting, variations, formulations and characteristics of biomaterials. This review also aims to discover all the areas of applications and scopes of further improvement of 3D bioprinters in this era of the Fourth Industrial Revolution.
Design/methodology/approach
This paper reviewed a number of papers that carried evaluations of different 3D bioprinting methods with different biomaterials, using different pumps to print 3D scaffolds, living cells, tissue and organs. All the papers and articles are collected from different journals and conference papers from 2014 to 2022.
Findings
This paper briefly explains how the concept of a 3D bioprinter was developed from a 3D printer and how it affects the biomedical field and helps to recover the lack of organ donors. It also gives a clear explanation of three basic processes and different strategies of these processes and the criteria of biomaterial selection. This paper gives insights into how 3D bioprinters can be assisted with machine learning to increase their scope of application.
Research limitations/implications
The chosen research approach may limit the generalizability of the research findings. As a result, researchers are encouraged to test the proposed hypotheses further.
Practical implications
This paper includes implications for developing 3D bioprinters, developing biomaterials and increasing the printability of 3D bioprinters.
Originality/value
This paper addresses an identified need by investigating how to enable 3D bioprinting performance.
Details