Additive manufacturing of polymer melts for implantable medical devices and scaffolds

Youssef, Almoatazbellah; Hollister, Scott J.; Dalton, Paul D.

doi:10.1088/1758-5090/aa5766

Cited by 168 publications

(122 citation statements)

References 221 publications

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“…Using air pressure, the melt is delivered to a charged nozzle where it is direct‐written onto a build plate as a molten fluid column, using an applied voltage to prevent Raleigh–Plateau instabilities . This permits large diameter nozzles to be used, for the production of fibers as small as 820 nm in diameter and as large as 140 µm, in planar or cylindrical rotating collector configurations out of various thermoplastic polymers . The direct‐writing of straight fibers is achieved when the speed is higher than a critical translation speed (CTS), which corresponds to the velocity of both the polymer jet and the collector (Figure B).…”

Section: The Effect Of Air Pressure On the Range Of Fiber Diameters Amentioning

confidence: 99%

Dimension‐Based Design of Melt Electrowritten Scaffolds

Hrynevich

Elçi

Haigh

et al. 2018

Small

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The electrohydrodynamic stabilization of direct-written fluid jets is explored to design and manufacture tissue engineering scaffolds based on their desired fiber dimensions. It is demonstrated that melt electrowriting can fabricate a full spectrum of various fibers with discrete diameters (2-50 µm) using a single nozzle. This change in fiber diameter is digitally controlled by combining the mass flow rate to the nozzle with collector speed variations without changing the applied voltage. The greatest spectrum of fiber diameters was achieved by the simultaneous alteration of those parameters during printing. The highest placement accuracy could be achieved when maintaining the collector speed slightly above the critical translation speed. This permits the fabrication of medical-grade poly(ε-caprolactone) into complex multimodal and multiphasic scaffolds, using a single nozzle in a single print. This ability to control fiber diameter during printing opens new design opportunities for accurate scaffold fabrication for biomedical applications.

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Section: The Effect Of Air Pressure On the Range Of Fiber Diameters Amentioning

confidence: 99%

Dimension‐Based Design of Melt Electrowritten Scaffolds

Hrynevich

Elçi

Haigh

et al. 2018

Small

Self Cite

193

234

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“…A major impact of this transformation is scalable customization, which facilitates rapid specialized part production. In this section, we provide an overview of current AM technologies, with an emphasis on techniques that advance the fabrication of precision biomaterials . In ref.…”

Section: Toolbox For Am Of Precision Biomaterialsmentioning

confidence: 99%

“…A limitation of common polymers employed in extrusion‐based AM of implantable biomaterials is their limited ability for biointegration . To improve cell adhesion and tissue integration, PCL, PLA, PLGA, and PEEK have been combined with inorganic additives that modify the chemical and physical properties of the implant surface that favor integration as well as modulate the mechanical properties of the final part . PCL has been combined with hydroxyapatite particles to generate goat femoral condyle replacements via FDM, which enabled homogeneous articular cartilage formation after 10 weeks in vivo .…”

Section: Toolbox For Am Of Precision Biomaterialsmentioning

confidence: 99%

Additive Manufacturing of Precision Biomaterials

2019

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Biomaterials play a critical role in modern medicine as surgical guides, implants for tissue repair, and as drug delivery systems. The emerging paradigm of precision medicine exploits individual patient information to tailor clinical therapy. While the main focus of precision medicine to date is the design of improved pharmaceutical treatments based on “‐omics” data, the concept extends to all forms of customized medical care. This includes the design of precision biomaterials that are tailored to meet specific patient needs. Additive manufacturing (AM) enables free‐form manufacturing and mass customization, and is a critical enabling technology for the clinical implementation of precision biomaterials. Materials scientists and engineers can contribute to the realization of precision biomaterials by developing new AM technologies, synthesizing advanced (bio)materials for AM, and improving medical‐image‐based digital design. As the field matures, AM is poised to provide patient‐specific tissue and organ substitutes, reproducible microtissues for drug screening and disease modeling, personalized drug delivery systems, as well as customized medical devices.

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“…The stiffness matching offers significantly better outcomes for patients and has been achieved by imposing specific levels and types of porosity on the NiTi parts. The use of additive manufacturing in the biomedical field is not limited to the fabrication of metallic parts, but it enables the fabrication of complex shapes for a wide range of materials, including polymers and polymer-based composites [29][30][31]. For example, Martorelli et al [32] used additive manufacturing to fabricate customized polymer-based composite mandibles that simulate the mechanical behavior of a human mandible.…”

Section: Introductionmentioning

confidence: 99%

In Vitro Corrosion Assessment of Additively Manufactured Porous NiTi Structures for Bone Fixation Applications

Ibrahim

Jahadakbar

Dehghan

et al. 2018

Metals

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NiTi alloys possess distinct functional properties (i.e., shape memory effect and superelasticity) and biocompatibility, making them appealing for bone fixation applications. Additive manufacturing offers an alternative method for fabricating NiTi parts, which are known to be very difficult to machine using conventional manufacturing methods. However, poor surface quality, and the presence of impurities and defects, are some of the major concerns associated with NiTi structures manufactured using additive manufacturing. The aim of this study is to assess the in vitro corrosion properties of additively manufactured NiTi structures. NiTi samples (bulk and porous) were produced using selective laser melting (SLM), and their electrochemical corrosion characteristics and Ni ion release levels were measured and compared with conventionally fabricated NiTi parts. The additively manufactured NiTi structures were found to have electrochemical corrosion characteristics similar to those found for the conventionally fabricated NiTi alloy samples. The highest Ni ion release level was found in the case of 50% porous structures, which can be attributed to their significantly higher exposed surface area. However, the Ni ion release levels reported in this work for all the fabricated structures remain within the range of most of values for conventionally fabricated NiTi alloys reported in the literature. The results of this study suggest that the proposed SLM fabrication process does not result in a significant deterioration in the corrosion resistance of NiTi parts, making them suitable for bone fixation applications.

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Additive manufacturing of polymer melts for implantable medical devices and scaffolds

Cited by 168 publications

References 221 publications

Dimension‐Based Design of Melt Electrowritten Scaffolds

Dimension‐Based Design of Melt Electrowritten Scaffolds

Additive Manufacturing of Precision Biomaterials

In Vitro Corrosion Assessment of Additively Manufactured Porous NiTi Structures for Bone Fixation Applications

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