scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Three-Dimensional Printing: A Catalyst for a Changing Orthopaedic Landscape.

01 Feb 2020-Jbjs reviews (Ovid Technologies (Wolters Kluwer Health))-Vol. 8, Iss: 2, pp 0076
TL;DR: Three-dimensional (3D) printing is an emerging tool in provider and patient education, surgical planning, and the design and implementation of medical devices and implants.
Abstract: Three-dimensional (3D) printing is an emerging tool in provider and patient education, surgical planning, and the design and implementation of medical devices and implants.Recent decreases in the cost of 3D printers along with advances in and cost reduction of printable materials have elevated 3D pr
Citations
More filters
Journal ArticleDOI
TL;DR: This study demonstrated that the printed blood vessels with two distinct cell layers of VECs and VSMCs could be potential candidates for clinical small-diameter blood vessel replacement applications.
Abstract: Blood vessel damage resulting from trauma or diseases presents a serious risk of morbidity and mortality. Although synthetic vascular grafts have been successfully commercialized for clinical use, they are currently only readily available for large-diameter vessels (>6 mm). Small-diameter vessel (<6 mm) replacements, however, still present significant clinical challenges worldwide. The primary objective of this study is to create novel, tunable, small-diameter blood vessels with biomimetic two distinct cell layers [vascular endothelial cell (VEC) and vascular smooth muscle cell (VSMC)] using an advanced coaxial 3D-bioplotter platform. Specifically, the VSMCs were laden in the vessel wall and VECs grew in the lumen to mimic the natural composition of the blood vessel. First, a novel bioink consisting of VSMCs laden in gelatin methacryloyl (GelMA)/polyethylene(glycol)diacrylate/alginate and lyase was designed. This specific design is favorable for nutrient exchange in an ambient environment and simultaneously improves laden cell proliferation in the matrix pore without the space restriction inherent with substance encapsulation. In the vessel wall, the laden VSMCs steadily grew as the alginate was gradually degraded by lyase leaving more space for cell proliferation in matrices. Through computational fluid dynamics simulation, the vessel demonstrated significantly perfusable and mechanical properties under various flow velocities, flow viscosities, and temperature conditions. Moreover, both VSMCs in the scaffold matrix and VECs in the lumen steadily proliferated over time creating a significant two-cell-layered structure. Cell proliferation was confirmed visually through staining the markers of alpha-smooth muscle actin and cluster of differentiation 31, commonly tied to angiogenesis phenomena, in the vessel matrices and lumen, respectively. Furthermore, the results were confirmed quantitatively through gene analysis which suggested good angiogenesis expression in the blood vessels. This study demonstrated that the printed blood vessels with two distinct cell layers of VECs and VSMCs could be potential candidates for clinical small-diameter blood vessel replacement applications.

61 citations

Journal ArticleDOI
TL;DR: Results indicated that RNTKs are a promising type of nanotubes for promoting chondrogenic differentiation, and the present 3D printed three-layer gradient GelMA-PEGDA-RNTK scaffold shows considerable promise for future cartilage repair and regeneration.
Abstract: Cartilage damage caused by aging, repeated overloading, trauma, and diseases can result in chronic pain, inflammation, stiffness, and even disability. Unlike other types of tissues (bone, skin, muscle, etc.), cartilage tissue has an extremely weak regenerative capacity. Currently, the gold standard surgical treatment for repairing cartilage damage includes autografts and allografts. However, these procedures are limited by insufficient donor sources and the potential for immunological rejection. After years of development, engineered tissue now provides a valuable artificial replacement for tissue regeneration purposes. Three-dimensional (3D) bioprinting technologies can print customizable hierarchical structures with cells. The objective of the current work was to prepare a 3D-printed three-layer gradient scaffold with lysine-functionalized rosette nanotubes (RNTK) for improving the chondrogenic differentiation of adipose-derived mesenchymal stem cells (ADSCs). Specifically, biologically inspired RNTKs were utilized in our work because they have unique surface chemistry and biomimetic nanostructure to improve cell adhesion and growth. Different ratios of gelatin methacrylate (GelMA) and poly(ethylene glycol) diacrylate (PEGDA) were printed into a three-layer GelMA-PEGDA gradient scaffold using a stereolithography-based printer, followed by coating with RNTKs. The pores and channels (∼500 μm) were observed in the scaffold. It was found that the population of ADSCs on the GelMA-PEGDA-RNTK scaffold increased by 34% compared to the GelMA-PEGDA scaffold (control). Moreover, after 3 weeks of chondrogenic differentiation, collagen II, glycosaminoglycan, and total collagen synthesis on the GelMA-PEGDA-RNTK scaffold significantly respectively increased by 59%, 71%, and 60%, as compared to the control scaffold. Gene expression of collagen II α1, SOX 9, and aggrecan in the ADSCs growing on the GelMA-PEGDA-RNTK scaffold increased by 79%, 52%, and 47% after 3 weeks, compared to the controls, respectively. These results indicated that RNTKs are a promising type of nanotubes for promoting chondrogenic differentiation, and the present 3D-printed three-layer gradient GelMA-PEGDA-RNTK scaffold shows considerable promise for future cartilage repair and regeneration.

47 citations

Journal ArticleDOI
TL;DR: 3D printed scaffolds were better to mimic tumor complexity and regulate cancer cell behavior than in vivo 2D culture models and provide strong evidence for the advantageous usage of 3D printed models, especially those which use GelMA-PEGDA hydrogels as the primary scaffold material for studying lung CSCs.

26 citations

Journal ArticleDOI
TL;DR: In this paper , the principles and processes of chemical, physical, and biological surface modification technologies on 3D printed titanium alloy implants are discussed in detail, and the challenges on antibacterial, osteogenesis, and mechanical properties of 3D-printed titanium alloy implant by surface modification are summarized.
Abstract: With the development of three-dimensional (3D) printed technology, 3D printed alloy implants, especially titanium alloy, play a critical role in biomedical fields such as orthopedics and dentistry. However, untreated titanium alloy implants always possess a bioinert surface that prevents the interface osseointegration, which is necessary to perform surface modification to enhance its biological functions. In this article, we discuss the principles and processes of chemical, physical, and biological surface modification technologies on 3D printed titanium alloy implants in detail. Furthermore, the challenges on antibacterial, osteogenesis, and mechanical properties of 3D-printed titanium alloy implants by surface modification are summarized. Future research studies, including the combination of multiple modification technologies or the coordination of the structure and composition of the composite coating are also present. This review provides leading-edge functionalization strategies of the 3D printed titanium alloy implants.

13 citations

Journal ArticleDOI
TL;DR: Budget 3D-printed endoprostheses are reported to be significantly cheaper than the popular counterparts manufactured from polypropylene polyester and to be perceived as a relatively safe procedure with a minimal complication rate.
Abstract: The high cost of biofabricated titanium mesh plates can make them out of reach for hospitals in low-income countries. To increase the availability of cranioplasty, the authors of this work investigated the production of polymer-based endoprostheses. Recently, cheap, popular desktop 3D printers have generated sufficient opportunities to provide patients with on-demand and on-site help. This study also examines the technologies of 3D printing, including SLM, SLS, FFF, DLP, and SLA. The authors focused their interest on the materials in fabrication, which include PLA, ABS, PET-G, PEEK, and PMMA. Three-dimensional printed prostheses are modeled using widely available CAD software with the help of patient-specific DICOM files. Even though the topic is insufficiently researched, it can be perceived as a relatively safe procedure with a minimal complication rate. There have also been some initial studies on the costs and legal regulations. Early case studies provide information on dozens of patients living with self-made prostheses and who are experiencing significant improvements in their quality of life. Budget 3D-printed endoprostheses are reliable and are reported to be significantly cheaper than the popular counterparts manufactured from polypropylene polyester.

10 citations

References
More filters
Journal ArticleDOI
TL;DR: The Mesenchymal and Tissue Stem Cell Committee of the International Society for Cellular Therapy proposes minimal criteria to define human MSC, believing this minimal set of standard criteria will foster a more uniform characterization of MSC and facilitate the exchange of data among investigators.

14,724 citations

Journal ArticleDOI
TL;DR: New fabrication techniques, such as solid-free form fabrication, can potentially be used to generate scaffolds with morphological and mechanical properties more selectively designed to meet the specificity of bone-repair needs.

5,470 citations

Journal ArticleDOI
TL;DR: An integrated tissue–organ printer (ITOP) that can fabricate stable, human-scale tissue constructs of any shape is presented and the incorporation of microchannels into the tissue constructs facilitates diffusion of nutrients to printed cells, thereby overcoming the diffusion limit of 100–200 μm for cell survival in engineered tissues.
Abstract: A challenge for tissue engineering is producing three-dimensional (3D), vascularized cellular constructs of clinically relevant size, shape and structural integrity. We present an integrated tissue-organ printer (ITOP) that can fabricate stable, human-scale tissue constructs of any shape. Mechanical stability is achieved by printing cell-laden hydrogels together with biodegradable polymers in integrated patterns and anchored on sacrificial hydrogels. The correct shape of the tissue construct is achieved by representing clinical imaging data as a computer model of the anatomical defect and translating the model into a program that controls the motions of the printer nozzles, which dispense cells to discrete locations. The incorporation of microchannels into the tissue constructs facilitates diffusion of nutrients to printed cells, thereby overcoming the diffusion limit of 100-200 μm for cell survival in engineered tissues. We demonstrate capabilities of the ITOP by fabricating mandible and calvarial bone, cartilage and skeletal muscle. Future development of the ITOP is being directed to the production of tissues for human applications and to the building of more complex tissues and solid organs.

1,960 citations

Journal ArticleDOI
TL;DR: In this review, recent advances in bone scaffolds are highlighted and aspects that still need to be improved are discussed.

1,737 citations

Journal ArticleDOI
TL;DR: The state-of-the-art of topological design and manufacturing processes of various types of porous metals, in particular for titanium alloys, biodegradable metals and shape memory alloys are reviewed.

1,393 citations