scholarly journals Electrospinning and Additive Manufacturing: Adding Three-Dimensionality to Electrospun Scaffolds for Tissue Engineering

2021 ◽  
Vol 9 ◽  
Author(s):  
James A. Smith ◽  
Elisa Mele
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Implant Design ◽  
Patient Specific ◽  
Processing Technologies ◽  
Cellular Behavior ◽  
Electrospun Scaffolds ◽  
Natural Architecture

The final biochemical and mechanical performance of an implant or scaffold are defined by its structure, as well as the raw materials and processing conditions used during its fabrication. Electrospinning and Additive Manufacturing (AM) are two contrasting processing technologies that have gained popularity amongst the fields of medical research i.e., tissue engineering, implant design, drug delivery. Electrospinning technology is favored for its ability to produce micro- to nanometer fibers from polymer solutions and melts, of which, the dimensions, alignment, porosity, and chemical composition are easily manipulatable to the desired application. AM, on the other hand, offers unrivalled levels of geometrical freedom, allowing highly complex components (i.e., patient-specific) to be built inexpensively within 24 hours. Hence, adopting both technologies together appears to be a progressive step in pursuit of scaffolds that better match the natural architecture of human tissues. Here, we present recent insights into the advances on hybrid scaffolds produced by combining electrospinning (melt electrospinning excluded) and AM, specifically multi-layered architectures consisting of alternating fibers and AM elements, and bioinks reinforced with fibers prior to AM. We discuss how cellular behavior (attachment, migration, and differentiation) is influenced by the co-existence of these micro- and nano-features.

scholarly journals Additive manufacturing in medical sciences: past, present and the future

2018 ◽  
Vol 5 (1) ◽  
pp. 201
Author(s):  
Lakshya P. Rathore ◽  
Naina Verma
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
Biological Tissue ◽  
Patient Specific ◽  
Basic Fact ◽  
Medical Sciences ◽  
Novel Technique ◽  
Patient Specific Implants ◽  
Tissue Replacement ◽  
The Future

Additive manufacturing (AM) is a novel technique that despite having been around for more than 35 years, has been underutilized. Its great advantage lies in the basic fact that it is incredibly customizable. Since its use was recognized in various fields of medicine like orthopaedics, otorhinolaryngology, ophthalmology etc, it has proved to be one of the most promising developments in most of them. Customizable orthotics, prosthetics and patient specific implants and tracheal splints are few of its advantages. And in the future too, the combination of tissue engineering with AM is believed to produce an immense change in biological tissue replacement.

scholarly journals Topology and FEA modeling and optimization of a patient-specific zygoma implant

2021 ◽  
Author(s):  
Abhijit Cholkar ◽  
David Kinahan ◽  
Dermot Brabazon
Keyword(s):  
Additive Manufacturing ◽  
Optimum Design ◽  
Optimization Technique ◽  
Operating Time ◽  
Topological Optimization ◽  
Implant Design ◽  
Patient Specific ◽  
Stainless Steel 316L ◽  
Element Analysis ◽  
Suitable Material

Additive manufacturing has proven to be a very beneficial production technology in the medical and healthcare industries. While existing for over four decades, recent work has seen great improvements in the quality of products; particularly in medical devices such as implants. Improved customization reduced operating time and increased cost-effectiveness associated with Metal AM for these products offers a new value proposition.  This paper investigates and evaluates modelling methods for the zygoma bone (human jawbone) and explores the most suitable material and optimum design for this critical biomedical implant. This paper proposes an innovative and efficient pre-process methodology that includes modelling, design validation, topological optimization, and numerical analysis. The method includes the generation of the model using reverse engineering of CT scan data and a topology optimization technique which makes the implant lightweight without causing excessive stress concentration. Static structural Finite Element Analysis was conducted to test three different biocompatible materials (Ti6Al4V, stainless steel 316L and CoCr alloys) which are commonly available for metal additive manufacturing. The stresses and conditions in the analysis were that of the human mastication process and all the implant design were tested with the three material types. The Taguchi method was used to determine the optimum design which was found to result in the highest mass reduction of 25% with Ti6Al4V as the implant material.

scholarly journals 3D printing of patient-specific implants for osteochondral defects: workflow for an MRI-guided zonal design

2021 ◽  
Author(s):  
David Kilian ◽  
Philipp Sembdner ◽  
Henriette Bretschneider ◽  
Tilman Ahlfeld ◽  
Lydia Mika ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Implant Design ◽  
Patient Specific ◽  
Osteochondral Defects ◽  
Technological Gap ◽  
Patient Specific Implants ◽  
Cad Cam ◽  
Magnetic Resonance Imaging Mri ◽  
Common Clinical Practice ◽  
Geometric Compatibility

Abstract Magnetic resonance imaging (MRI) is a common clinical practice to visualize defects and to distinguish different tissue types and pathologies in the human body. So far, MRI data have not been used to model and generate a patient-specific design of multilayered tissue substitutes in the case of interfacial defects. For orthopedic cases that require highly individual surgical treatment, implant fabrication by additive manufacturing holds great potential. Extrusion-based techniques like 3D plotting allow the spatially defined application of several materials, as well as implementation of bioprinting strategies. With the example of a typical multi-zonal osteochondral defect in an osteochondritis dissecans (OCD) patient, this study aimed to close the technological gap between MRI analysis and the additive manufacturing process of an implant based on different biomaterial inks. A workflow was developed which covers the processing steps of MRI-based defect identification, segmentation, modeling, implant design adjustment, and implant generation. A model implant was fabricated based on two biomaterial inks with clinically relevant properties that would allow for bioprinting, the direct embedding of a patient’s own cells in the printing process. As demonstrated by the geometric compatibility of the designed and fabricated model implant in a stereolithography (SLA) model of lesioned femoral condyles, a novel versatile CAD/CAM workflow was successfully established that opens up new perspectives for the treatment of multi-zonal (osteochondral) defects. Graphic abstract

scholarly journals Effect of Different Porosity Ratio on Mechanical Properties of Polycaprolactone and Polylactic Acid Scaffolds

2018 ◽  
Vol 1 (1) ◽  
pp. 1243-1248
Author(s):  
Adem Demir ◽  
Mustafa Keser ◽  
Fatih Çalışkan
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Pore Size ◽  
Polylactic Acid ◽  
Mechanical Performance ◽  
Patient Specific ◽  
Porous Scaffolds ◽  
Medical Field ◽  
Tissue Engineering Scaffolds ◽  
Porosity Ratio

In recent years, patient-specific solutions and additive manufacturing (AM) have become increasingly important in the treatment of bone defects in studies performed on the medical field. In this direction, additive manufacturing methods use in scaffold fabrication, and many advantages of these systems come to the forefront. Porosity affects the mechanical properties, biocompatibility, and biodegradability of tissue engineering scaffolds. In this study, the effect of different porosity ratios on the mechanical properties of scaffolds for polylactic acid (PLA) and polycaprolactone (PCL) scaffolds was studied. With this fabrication method can be formed entirely 3D interconnected porous scaffolds with pore size. Three different (20%, 35%, and 50%) porosity ratios were determined for both materials, and the mechanical properties of the samples were determined by compression test. The scaffolds fabricated with larger pore size showed lower mechanical performance compared to scaffolds with smaller pore size.

BIOMODELLING OF CRANIO-MAXILLOFACIAL IMPLANT APPLYING OPEN SOURCE SOFTWARE

2015 ◽  
Vol 76 (7) ◽  
Author(s):  
Johari Yap Abdullah ◽  
Zainul Ahmad Rajion ◽  
Marzuki Omar
Keyword(s):  
Additive Manufacturing ◽  
Open Source ◽  
Open Source Software ◽  
Computer Modelling ◽  
3D Models ◽  
Physical Models ◽  
Implant Design ◽  
Patient Specific ◽  
Anatomical Structures ◽  
Computer Aided

Advances in craniofacial medical imaging has allowed the 3D reconstruction of anatomical structures for medical applications, including the design of patient specific implants based on computer-aided design and computer-aided manufacturing (CAD/CAM) platforms. This technology has provided new possibilities to visualize complex medical data through generation of 3–dimensional (3D) physical models via additive manufacturing that can be eventually utilised to assist in diagnosis, surgical planning, implant design, and patient management. Although the study on the construction of cranio-maxillofacial implant based on computer modelling and advanced biomaterial are growing rapidly from other parts of the world, however, in Malaysia is scanty, especially with open source application. For this reason, it leads us to embark in a study to produce a potential locally cranio-maxillofacial implant with equivalent standard as compared to the commercially available product applying open source software. As part of four sub-projects of USM Research University Team (RUT) project, the authors had investigated and applied open source software to perform image processing of CT data, to segment the region of interest of anatomical structures, to create virtual 3D models, and finally to convert the virtual 3D models to a format that compatible for additive manufacturing platform. Further research is ongoing to investigate on designing the cranio-maxillofacial implant using open source CAD software using suitable biomaterial.  

scholarly journals Additive Manufacturing of Prostheses Using Forest-Based Composites

2020 ◽  
Vol 7 (3) ◽  
pp. 103
Author(s):  
Erik Stenvall ◽  
Göran Flodberg ◽  
Henrik Pettersson ◽  
Kennet Hellberg ◽  
Liselotte Hermansson ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Industrial Applications ◽  
Layer By Layer ◽  
Biobased Materials ◽  
Fused Deposition ◽  
Custom Made ◽  
Transtibial Prosthesis

A custom-made prosthetic product is unique for each patient. Fossil-based thermoplastics are the dominant raw materials in both prosthetic and industrial applications; there is a general demand for reducing their use and replacing them with renewable, biobased materials. A transtibial prosthesis sets strict demands on mechanical strength, durability, reliability, etc., which depend on the biocomposite used and also the additive manufacturing (AM) process. The aim of this project was to develop systematic solutions for prosthetic products and services by combining biocomposites using forestry-based derivatives with AM techniques. Composite materials made of polypropylene (PP) reinforced with microfibrillated cellulose (MFC) were developed. The MFC contents (20, 30 and 40 wt%) were uniformly dispersed in the polymer PP matrix, and the MFC addition significantly enhanced the mechanical performance of the materials. With 30 wt% MFC, the tensile strength and Young´s modulus was about twice that of the PP when injection molding was performed. The composite material was successfully applied with an AM process, i.e., fused deposition modeling (FDM), and a transtibial prosthesis was created based on the end-user’s data. A clinical trial of the prosthesis was conducted with successful outcomes in terms of wearing experience, appearance (color), and acceptance towards the materials and the technique. Given the layer-by-layer nature of AM processes, structural and process optimizations are needed to maximize the reinforcement effects of MFC to eliminate variations in the binding area between adjacent layers and to improve the adhesion between layers.

Additive Manufacturing of Carbon Nanotube Reinforced Bioactive Glass Scaffolds for Bone Tissue Engineering

2021 ◽  
Author(s):  
Kartikeya Dixit ◽  
Niraj Sinha
Keyword(s):  
Tissue Engineering ◽  
Compressive Strength ◽  
Carbon Nanotube ◽  
Additive Manufacturing ◽  
Bioactive Glass ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Patient Specific ◽  
Polymer Foam ◽  
Native Bone

Abstract Scaffolds play an essential role in bone healing by providing temporary structural support to the native bone tissue and by hosting bone cells. To this end, several biomaterials and manufacturing methods have been proposed. Among the biomaterials, bioactive glasses have attractive properties as a scaffold material for bone repair. Simultaneously, additive manufacturing (AM) techniques have attracted significant attention owing to their capability of fabricating complex and patient specific scaffolds. Accordingly, borosilicate bioactive glass (BG-B30) has been used to fabricate the scaffolds using extrusion-based AM device in this study. Pluronic F-127 was used as an ink carrier that showed suitable shear thinning behavior for fabrication. The pure BG-B30 scaffold had a compressive strength of 23.30 MPa and was reinforced further with functionalized multi-walled carbon nanotube (MWCNT-COOH) to reduce its brittleness and enhance its compressive strength. When compared to the conventional polymer foam replication technique, the combination of MWCNT-COOH reinforcement and AM resulted in an enhancement of the compressive strength by ~646% (1.05 MPa to 35.84 MPa). Further, structural analysis using micro computed tomography revealed that the scaffolds fabricated using AM had better control over strut size and pore size in addition to better network connectivity. Finally, in vitro experiments demonstrated its bioactive behavior by formation of hydroxyapatite, and the cellular studies revealed good cell viability and osteogenesis initiation. These results are promising for the fabrication of patient-specific CNT-reinforced bioactive glass porous scaffolds for bone tissue engineering applications.

scholarly journals Poly(Vinyl Alcohol)-Based Nanofibrous Electrospun Scaffolds for Tissue Engineering Applications

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 7 ◽  
Author(s):  
Marta A. Teixeira ◽  
M. Teresa P. Amorim ◽  
Helena P. Felgueiras
Keyword(s):  
Tissue Engineering ◽  
Vinyl Alcohol ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Poly Vinyl Alcohol ◽  
Electrospinning Technique ◽  
Electrospun Scaffolds ◽  
Nanofibrous Scaffolds ◽  
The Stability ◽  
The Many

Tissue engineering (TE) holds an enormous potential to develop functional scaffolds resembling the structural organization of native tissues, to improve or replace biological functions and prevent organ transplantation. Amongst the many scaffolding techniques, electrospinning has gained widespread interest because of its outstanding features that enable the production of non-woven fibrous structures with a dimensional organization similar to the extracellular matrix. Various polymers can be electrospun in the form of three-dimensional scaffolds. However, very few are successfully processed using environmentally friendly solvents; poly(vinyl alcohol) (PVA) is one of those. PVA has been investigated for TE scaffolding production due to its excellent biocompatibility, biodegradability, chemo-thermal stability, mechanical performance and, most importantly, because of its ability to be dissolved in aqueous solutions. Here, a complete overview of the applications and recent advances in PVA-based electrospun nanofibrous scaffolds fabrication is provided. The most important achievements in bone, cartilage, skin, vascular, neural and corneal biomedicine, using PVA as a base substrate, are highlighted. Additionally, general concepts concerning the electrospinning technique, the stability of PVA when processed, and crosslinking alternatives to glutaraldehyde are as well reviewed.

Additive Manufacturing: Exploration of Porosity and Form Features Using Layer by Layer Deposition

2012 ◽  
Author(s):  
Devdas Shetty ◽  
Daniel Ly
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Raw Materials ◽  
High Strength ◽  
Complex Geometries ◽  
Layer By Layer ◽  
Monitoring And Control ◽  
Process Qualification ◽  
The Creation ◽  
Form Features

Aerospace companies use high-strength metal alloys like Inconel or Titanium which could be very difficult to fabricate using conventional methods. The current manufacturing techniques result in significant waste. Additive Manufacturing (AM), in its current state is not sufficiently understood, nor characterized such that conventional design practices and process qualification methodologies can be used. In addition, AM cannot be considered for the manufacture of aircraft components unless the process is stable and controlled. The mechanical properties of fabricated parts require to be characterized to demonstrate their invariability. The laser deposition using complex geometries is a challenge. In addition, the structural performances of AM parts have to be proved. Inherent in these requirements is the need to develop a process specification which requires the monitoring and control of key raw materials, consumables, and process parameters; the development of a fixed practice for each of the AM process. Several procedures are required in order to understand how additive manufacturing works using advanced and complex design models. The ability to adopt AM to the production of components is not only predicated on the ability of AM to be competitive with conventional manufacturing methods in terms of cost, but also on its ability to deliver parts with repeatable mechanical performance. The objective of this paper is to define and characterize the limitation of various complex geometries using additive manufacturing. The experimental research involved the creation of a number of specimens using direct metal laser sintering process, examination of their form features, documenting DMLS geometry limits for the form features and finally the creation of calibration models that can be used in aerospace design manuals.

Additive manufacturing of hydroxyapatite and its composite materials: A review

2020 ◽  
Vol 05 (03) ◽  
pp. 2030002
Author(s):  
Chunze Yan ◽  
Gao Ma ◽  
Annan Chen ◽  
Ying Chen ◽  
Jiamin Wu ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
Composite Materials ◽  
Computer Aided Design ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Research Field ◽  
Manufacturing Processes ◽  
Layer By Layer ◽  
Tissue Engineering Scaffolds

Hydroxyapatite (HA) is a promising biomaterial for tissue engineering scaffolds due to its similar performance and composition to natural bone. However, the brittleness and poor toughness of pure HA limit its clinical application. Therefore, a lot of HA composites have been prepared to improve their mechanical performance. Fabricating complex and customized tissue engineering HA scaffolds have a very high requirement for manufacturing processes. It is difficult to fabricate ideal HA porous structures for artificial bone implants using traditional manufacturing processes, such as plasma spraying–sintering, and injection forming. Additive manufacturing (AM) could make three-dimensional physical parts with complex structures directly from computer-aided-design (CAD) models in a layer-by-layer way, and therefore show unique advantages in fabricating bone tissue engineering scaffolds with complex external shape and internal microporous structures. This paper reviews the state of the art for the preparation and AM process of HA and its composite materials, and raises the prospects for this research field.

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