3D-printed porous Ti6Al4V alloys with silver coating combine osteocompatibility and antimicrobial properties

Electrospinning is a frequently used method to prepare air and water filters. Electrospun nanofiber mats can have very small pores, allowing for filtering of even the smallest particles or molecules. In addition, their high surface-to-volume ratio allows for the integration of materials which may additionally treat the filtered material through photo-degradation, possess antimicrobial properties, etc., thus enhancing their applicability. However, the fine nanofiber mats are prone to mechanical damage. Possible solutions include reinforcement by embedding them in composites or gluing them onto layers that are more mechanically stable. In a previous study, we showed that it is generally possible to stabilize electrospun nanofiber mats by 3D printing rigid polymer layers onto them. Since this procedure is not technically easy and needs some experience to avoid delamination as well as damaging the nanofiber mat by the hot nozzle, here we report on the reversed technique (i.e., first 3D printing a rigid scaffold and subsequently electrospinning the nanofiber mat on top of it). We show that, although the adhesion between both materials is insufficient in the case of a common rigid printing polymer, nanofiber mats show strong adhesion to 3D printed scaffolds from thermoplastic polyurethane (TPU). This paves the way to a second approach of combining 3D printing and electrospinning in order to prepare mechanically stable filters with a nanofibrous surface.

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Utilization of Antibacterial Nanoparticles in Photocurable Additive Manufacturing of Advanced Composites for Improved Public Health

Polymers ◽

10.3390/polym13162616 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2616

Author(s):

Christopher Billings ◽

Changjie Cai ◽

Yingtao Liu

Keyword(s):

Public Health ◽

Tensile Strength ◽

Additive Manufacturing ◽

Abrasion Resistance ◽

Antimicrobial Properties ◽

Digital Light Processing ◽

Antimicrobial Function ◽

3D Printed ◽

Commercial Applications ◽

Antibacterial Nanoparticles

This paper presents the additive manufacturing and characterization of nanoparticle-reinforced photocurable resin-based nanocomposites with a potential antimicrobial function for improved public health applications. Two types of photocurable resins are reinforced by titanium dioxide (TiO2) or zinc oxide (ZnO) nanoparticles with average diameters in the 10–30 nm range to provide antimicrobial properties. The developed nanocomposites can be additively manufactured using the digital light processing method with an outstanding surface quality and precise geometrical accuracy. Experimental characterizations are conducted to investigate key mechanical properties of the 3D printed nanocomposites, including Young’s Modulus, tensile strength, and abrasion resistance. Specimens produced were observed to demonstrate the following characteristics during testing. Tensile strength increased by 42.2% at a maximum value of 29.53 MPa. The modulus of elasticity increased by 14.3%, and abrasion resistance increased by 15.8%. The proper dispersion of the nanoparticles within the cured resin is validated by scanning electron images. The wettability and water absorption testing results indicate that the developed nanocomposites have an outstanding water resistance capability. The pairing of digital light processing with these novel nanocomposites allows for the creation of complex composite geometries that are not capable through other manufacturing processes. Therefore, they have the potential for long-term usage to improve general public health with antimicrobial functionality. The pairing of an unmodified photocurable resin with a 1% ZnO concentration demonstrated the most promise for commercial applications.

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Three-Dimensional Printed Antimicrobial Objects of Polylactic Acid (PLA)-Silver Nanoparticle Nanocomposite Filaments Produced by an In-Situ Reduction Reactive Melt Mixing Process

Biomimetics ◽

10.3390/biomimetics5030042 ◽

2020 ◽

Vol 5 (3) ◽

pp. 42 ◽

Cited By ~ 2

Author(s):

Nectarios Vidakis ◽

Markos Petousis ◽

Emmanouel Velidakis ◽

Marco Liebscher ◽

Lazaros Tzounis

Keyword(s):

Polylactic Acid ◽

Silver Nanoparticle ◽

Antimicrobial Properties ◽

P Value ◽

In Situ Reduction ◽

Fused Filament Fabrication ◽

Melt Mixing ◽

3D Printed ◽

Reactive Melt

In this study, an industrially scalable method is reported for the fabrication of polylactic acid (PLA)/silver nanoparticle (AgNP) nanocomposite filaments by an in-situ reduction reactive melt mixing method. The PLA/AgNP nanocomposite filaments have been produced initially reducing silver ions (Ag+) arising from silver nitrate (AgNO3) precursor mixed in the polymer melt to elemental silver (Ag0) nanoparticles, utilizing polyethylene glycol (PEG) or polyvinyl pyrrolidone (PVP), respectively, as macromolecular blend compound reducing agents. PEG and PVP were added at various concentrations, to the PLA matrix. The PLA/AgNP filaments have been used to manufacture 3D printed antimicrobial (AM) parts by Fused Filament Fabrication (FFF). The 3D printed PLA/AgNP parts exhibited significant AM properties examined by the reduction in Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria viability (%) experiments at 30, 60, and 120 min duration of contact (p < 0.05; p-value (p): probability). It could be envisaged that the 3D printed parts manufactured and tested herein mimic nature’s mechanism against bacteria and in terms of antimicrobial properties, contact angle for their anti-adhesive behavior and mechanical properties could create new avenues for the next generation of low-cost and on-demand additive manufacturing produced personal protective equipment (PPE) as well as healthcare and nosocomial antimicrobial equipment.

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Studies on the cytocompatibility, mechanical and antimicrobial properties of 3D printed poly(methyl methacrylate) beads

Bioactive Materials ◽

10.1016/j.bioactmat.2018.01.006 ◽

2018 ◽

Vol 3 (2) ◽

pp. 157-166 ◽

Cited By ~ 15

Author(s):

David K. Mills ◽

Uday Jammalamadaka ◽

Karthik Tappa ◽

Jeffery Weisman

Keyword(s):

Methyl Methacrylate ◽

Antimicrobial Properties ◽

Poly Methyl Methacrylate ◽

3D Printed

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Incorporation of graphene oxide into poly(ɛ-caprolactone) 3D printed fibrous scaffolds improves their antimicrobial properties

Materials Science and Engineering C ◽

10.1016/j.msec.2019.110537 ◽

2020 ◽

Vol 109 ◽

pp. 110537 ◽

Cited By ~ 2

Author(s):

Sofia F. Melo ◽

Sara C. Neves ◽

Andreia T. Pereira ◽

Inês Borges ◽

Pedro L. Granja ◽

...

Keyword(s):

Graphene Oxide ◽

Antimicrobial Properties ◽

Fibrous Scaffolds ◽

3D Printed

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A New 4 × 4 Rectangular Waveguide Short-Slot Coupler in 3D Printed Technology at Ku-Band

Electronics ◽

10.3390/electronics9040610 ◽

2020 ◽

Vol 9 (4) ◽

pp. 610

Author(s):

Raúl V. Haro-Baez ◽

Jorge A. Ruiz-Cruz ◽

Juan Córcoles ◽

José R. Montejo-Garai ◽

Jesús M. Rebollar

Keyword(s):

3D Printing ◽

Rectangular Waveguide ◽

High Performance ◽

Low Cost ◽

Silver Coating ◽

Compact Structure ◽

Coupling Region ◽

3D Printed ◽

Good Trade ◽

Novel Design

This paper presents a novel design of an eight-port directional coupler with a very compact structure and simple manufacturing, working in the Ku frequency band. One of the main goals of the design was to ease the manufacturing with a simple structure: the coupler consisted of four rectangular waveguide input ports, four rectangular waveguide output ports, and a central coupling region with only H-plane variation. A prototype was fabricated using additive manufacturing, with a combination of 3D printing and silver coating metallization. The obtained performance showed a theoretical bandwidth of 6.6% with 20 dB return loss for the input/output ports. Good agreement between simulations and measurements was obtained, validating the proposed coupler as a good trade-off for low cost 3D printing, compactness, and high performance for systems requiring a high number of ports as in phase arrays or Butler matrices.

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Antibacterial Performance Evaluation of Silver Coated River Sand for Water Decontamination Application

Defence Life Science Journal ◽

10.14429/dlsj.6.16031 ◽

2021 ◽

Vol 6 (3) ◽

pp. 214-221

Author(s):

Rama Dubey ◽

Swagata Goswami ◽

Sonika Sharma ◽

Dhiraj Dutta ◽

Sanjai Kumar Dwivedi

Keyword(s):

Drinking Water ◽

Health Hazard ◽

Antimicrobial Properties ◽

Microbial Reduction ◽

Fecal Coliforms ◽

Diffusion Method ◽

Silver Coating ◽

Contaminated Water ◽

River Sand ◽

Antibacterial Performance

The presence of microbes in drinking water is a serious health hazard demanding immediate attention. Silver is known for centuries for its highly effective antimicrobial properties against a variety of microorganisms. Sand is a natural filter media that is widely used in water purification systems for the removal of dirt and suspended matter from water. Hence the development of additional antimicrobial features in commonly used filter material i.e. sand by coating with silver is an alternative technology for providing a safe drinking-water free from microbes. The present study was performed to develop a cost-effective material with antimicrobial properties by coating locally available river sand with silver. The coated material was subsequently used for its antimicrobial performance by using standard methods. To perform the tests E.coli was isolated from wastewater by using standard microbiological protocols. Thereafter, a biochemical test and antibiotic sensitivity assay were performed. Synthesised silver-coated sand was tested for its antibacterial activity against E.coli through the agar well diffusion method. The results showed a zone of clearance ≥40 mm with 700 mg of synthesised sample. To further determine the efficacy of developed material against E.coli load in artificially contaminated water, experiments were conducted by passing contaminated water through the material stuffed inside a hollow tube filter. A colony count reduction of 86.67 per cent was observed on passing 1000 ml of 3x103 CFU/ml contaminated water through the filter. The present study suggests that additional functionality of microbial reduction can be introduced in the sand through the silver coating. The developed material can be effectively used for the removal of fecal coliforms (E.coli) present in water bodies at an effective cost in addition to the removal of traditional impurities like dirt and suspended materials.

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Surface finish of Additively Manufactured Metals: biofilm formation and cellular attachment

10.25518/esaform21.2089 ◽

2021 ◽

Author(s):

Paola Ginestra ◽

Leonardo Riva ◽

Elisabetta Ceretti ◽

David Lobo ◽

Sophie Mountcastle ◽

...

Keyword(s):

Surface Properties ◽

High Performance ◽

Antimicrobial Properties ◽

Region Of Interest ◽

Titanium Implants ◽

Surface Finishing ◽

Layer By Layer ◽

Post Processing ◽

3D Printed ◽

Manufacturing Technologies

Powder bed fusion techniques enable the production of customized and complex devices that meet the requirements of the end user and target application. The medical industry relies on these additive manufacturing technologies for the advantages that these methods offer to accurately fit the patients’ needs. Besides the recent improvements, the production process of 3D printed bespoke implants still requires optimization to achieve the optimal properties that can mimic both the chemical and mechanical characteristics of the anatomical region of interest. In particular, the surface properties of an implant device are crucial to obtain a strong interface and connection with the physiological environment. The layer by layer manufacturing processes lead to the production of complex and high-performance substrates but always require surface treatments during post-processing to improve the implant interaction with the natural tissues and promote a shorter assimilation for the fast recovery and wellness of the patient. Although the surface finishing can be tailored to enhance cells adhesion, proliferation and differentiation in contact with a metal implant, the same surface properties can have a different outcome when dealing with bacteria. This work aims to provide a preliminary analysis on how different post-processing techniques have distinct effects on cells and bacteria colonization of 3D printed titanium implants. The goal of the paper is to highlight the importance of the identification of an optimized methodology for the surface treatment of Ti6Al4V samples produced by Selective Laser Melting (SLM) that improves the implant antimicrobial properties and promotes the osseointegration in a long-term period.

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Enhanced Mechanical, Thermal and Antimicrobial Properties of Additively Manufactured Polylactic Acid with Optimized Nano Silica Content

Nanomaterials ◽

10.3390/nano11041012 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1012

Author(s):

Nectarios Vidakis ◽

Markos Petousis ◽

Emanuel Velidakis ◽

Nikolaos Mountakis ◽

Lazaros Tzounis ◽

...

Keyword(s):

Polylactic Acid ◽

Three Dimensional ◽

Antibacterial Properties ◽

Antimicrobial Properties ◽

Sio2 Nanoparticles ◽

International Standards ◽

Fused Filament Fabrication ◽

Melt Mixing ◽

Screening Process ◽

3D Printed

The scope of this work was to create, with melt mixing compounding process, novel nanocomposite filaments with enhanced properties that industry can benefit from, using commercially available materials, to enhance the performance of three-dimensional (3D) printed structures fabricated via fused filament fabrication (FFF) process. Silicon Dioxide (SiO2) nanoparticles (NPs) were selected as fillers for a polylactic acid (PLA) thermoplastic matrix at various weight % (wt.%) concentrations, namely, 0.5, 1.0, 2.0 and 4.0 wt.%. Tensile, flexural and impact test specimens were 3D printed and tested according to international standards and their Vickers microhardness was also examined. It was proven that SiO2 filler enhanced the overall strength at concentrations up to 1 wt.%, compared to pure PLA. Atomic force microscopy (AFM) was employed to investigate the produced nanocomposite extruded filaments roughness. Raman spectroscopy was performed for the 3D printed nanocomposites to verify the polymer nanocomposite structure, while thermogravimetric analysis (TGA) revealed the 3D printed samples’ thermal stability. Scanning electron microscopy (SEM) was carried out for the interlayer fusion and fractography morphological characterization of the specimens. Finally, the antibacterial properties of the produced nanocomposites were investigated with a screening process, to evaluate their performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

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