scholarly journals Design of Highly Porous Hydroxyapatite Scaffolds by Conversion of 3D Printed Gypsum Structures – A Comparison Study

Procedia CIRP ◽  
2016 ◽  
Vol 49 ◽  
pp. 55-60 ◽  
Author(s):  
Alan C.S. Dantas ◽  
Debora H. Scalabrin ◽  
Roberta De Farias ◽  
Amanda A. Barbosa ◽  
Andrea V. Ferraz ◽  
...  
2021 ◽  
Author(s):  
Md Towhidul Islam ◽  
Laura Macri-Pellizzeri ◽  
Virginie Sottile ◽  
Ifty Ahmed

This paper reports on the rapid development of porous hydroxyapatite (HA) microspheres with large external pores and fully interconnected porosity.


Author(s):  
Michelle P. Browne ◽  
James Dodwell ◽  
Filip Novotny ◽  
Sonia Jaśkaniec ◽  
Paul R. Shearing ◽  
...  

In academic labs, most oxygen evolution reaction studies are carried out in conventional three-electrode cell set-ups; however, this configuration may not accurately represent conditions experienced under practical electrolyser conditions.


2019 ◽  
Vol 39 (15) ◽  
pp. 4680-4687 ◽  
Author(s):  
Haize Jin ◽  
Zhihua Yang ◽  
Jing Zhong ◽  
Delong Cai ◽  
Hailiang Li ◽  
...  

2019 ◽  
Vol 101-B (7_Supple_C) ◽  
pp. 40-47 ◽  
Author(s):  
S. Sporer ◽  
L. MacLean ◽  
A. Burger ◽  
M. Moric

AimsOur intention was to investigate if the highly porous biological fixation surfaces of a new 3D-printed total knee arthroplasty (TKA) achieved adequate fixation of the tibial and patellar components to the underlying bone.Patients and MethodsA total of 29 patients undergoing primary TKA consented to participate in this prospective cohort study. All patients received a highly porous tibial baseplate and metal-backed patella. Patient-reported outcomes measures were recorded and implant migration was assessed using radiostereometric analysis.ResultsPatient function significantly improved by three months postoperatively (p < 0.001). Mean difference in maximum total point motion between 12 and 24 months was 0.021 mm (-0.265 to 0.572) for the tibial implant and 0.089 mm (-0.337 to 0.758) for the patellar implant. The rate of tibial and patellar migration was largest over the first six postoperative weeks, with no changes in mean tibia migration occurring after six months, and no changes in mean patellar migration occurring after six weeks. One patellar component showed a rapid rate of migration between 12 and 24 months.ConclusionBiological fixation appears to occur reliably on the highly porous implant surface of the tibial baseplate and metal-backed patellar component. Rapid migration after 12 months was measured for one patellar component. Further investigation is required to assess the long-term stability of the 3D-printed components and to determine if the high-migrating components achieve fixation. Cite this article: Bone Joint J 2019;101-B(7 Supple C):40–47


2010 ◽  
Vol 63 ◽  
pp. 408-413 ◽  
Author(s):  
Hrvoje Ivankovic ◽  
Sebastijan Orlic ◽  
Dajana Kranzelic ◽  
Emilija Tkalcec

Highly porous hydroxyapatite (Ca10(PO4)6(OH)2, HA) was prepared through hydrothermal (HT) transformation of aragonitic cuttlefish bones (Seppia Officinalis L. Adriatic Sea) in the temperature range from 140°C to 220°C for 20 minutes to 48 hours. Mechanism of hydrothermal transformation of bones was investigated by DTA/TG analyzer coupled online with FTIR spectrometric gas cell equipment (DTA-TG-EGA-FTIR analysis), X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). DTA-TG-EGA-FTIR analysis have shown the release of CO2 at about 400°C, 680°C and 990°C. The first release could be attributed to organics not completely removed from the heat treated bones, and the second release to decomposition of unconverted aragonite, whereas, the third one could be attributed to CO3 2– groups incorporated in the structure of HA. The interconnecting porous morphology of the starting material (aragonite) was maintained during the HT treatment. The formation of dandelion-like HA spheres with diameter from 3 to 8 μm were observed, which further transformed into nanoplates and nanorods with an average diameter of about 200-300 nm and an average length of about 8-10 μm.


2020 ◽  
Author(s):  
Yang Li ◽  
Xinguang Wang ◽  
Hua Tian

Abstract Background: The reconstruction of massive bone defects is one of the main challenges in revision total knee arthroplasty (RTKA). Although several methods are available, each of them has its prominent shortcomings. The purpose of this study is to review the clinical outcomes of RTKA with massive proximal tibial bone defects using patient-customized three-dimensional (3D)-printed highly porous metaphyseal cones.Methods: We retrospectively reviewed seven RTKAs with Anderson Orthopaedic Research Institute (AORI) type III tibial defects using patient-customized 3D-printed highly porous metaphyseal cones, which have been performed at a single institution between 2016 and 2018. Results: The mean age at diagnosis of the patients was 68 years old (61-77). The mean length of follow-up was 25.3 months (19-36). At the latest follow-up, no aseptic loosening or prosthetic joint infection has been determined. The mean HSS increased from 49 (39-63) to 78 (70-83) (P<0.01); the mean WOMAC increased from 59 (46-73) to 26 (12-38) (P<0.01). All patients obtained the range of motion and mechanical alignment improvement postoperatively.Conclusion: The patient-customized 3D-printed metaphyseal cone could be a promising technique in addressing severe tibial defects in RTKA. Our study shows encouraging short-term clinical and radiological outcomes with no aseptic loosening, periprosthetic infection, or fracture. Nevertheless, further follow-up and the expansion of sample size are needed to demonstrate the advantage of this innovative technique fully.


Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6127
Author(s):  
Nguyen Van Hoa ◽  
Nguyen Cong Minh ◽  
Hoang Ngoc Cuong ◽  
Pham Anh Dat ◽  
Pham Viet Nam ◽  
...  

Dye and heavy metal contaminants are mainly aquatic pollutants. Although many materials and methods have been developed to remove these pollutants from water, effective and cheap materials and methods are still challenging. In this study, highly porous hydroxyapatite/graphene oxide/chitosan beads (HGC) were prepared by a facile one-step method and investigated as efficient adsorbents. The prepared beads showed a high porosity and low bulk density. SEM images indicated that the hydroxyapatite (HA) nanoparticles and graphene oxide (GO) nanosheets were well dispersed on the CTS matrix. FT-IR spectra confirmed good incorporation of the three components. The adsorption behavior of the obtained beads to methylene blue (MB) and copper ions was investigated, including the effect of the contact time, pH medium, dye/metal ion initial concentration, and recycle ability. The HGC beads showed rapid adsorption, high capacity, and easy separation and reused due to the porous characteristics of GO sheets and HA nanoparticles as well as the rich negative charges of the chitosan (CTS) matrix. The maximum sorption capacities of the HGC beads were 99.00 and 256.41 mg g−1 for MB and copper ions removal, respectively.


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