scholarly journals 4464 Effect of Surface Topography on In Vitro and Mechanical Performance of 3D Printed Titanium

2020 ◽  
Vol 4 (s1) ◽  
pp. 130-130
Author(s):  
Bijan Abar ◽  
Cambre Kelly ◽  
Anh Pham ◽  
Nicholas Allen ◽  
Helena Barber ◽  
...  
Keyword(s):  
Cell Growth ◽  
Tensile Testing ◽  
Mechanical Performance ◽  
Quantitative Polymerase Chain Reaction ◽  
Fluorescent Microscopy ◽  
Cell Activity ◽  
Implant Fixation ◽  
Cell Viability Assay ◽  
3D Printed

OBJECTIVES/GOALS: The goal of the study is to understand how changing the surface roughness of 3D printed Titanium either by processing printed samples or artificially printing rough topography impacts the mechanical and biological properties of the Titanium. METHODS/STUDY POPULATION: Titanium dog bones and discs were printed via laser powder bed fusion. groups were defined as 1. polished, 2.blasted, 4.as built, 4.sprouts and 5.rough sprouts. Roughness was measured with line measurement using a confocal microscope. Tensile testing of dog bones produced stress strain curves. MC3T3 preosteoblast were seeded on discs. Samples were analyzed at 0, 2, and 4 weeks. A cell viability assay and confocal fluorescent microscopy assessed cell growth. Alkaline Phosphatase (ALP) assay and Quantitative Polymerase Chain Reaction (qPCR) examined cell differentiation. Extracellular matrix (ECM) was stained for collagen and calcium. Scanning Electron Microcopy (SEM) was done on sputter coated discs. RESULTS/ANTICIPATED RESULTS: Measured roughness defined by Rz, maximum peak to valley distance of the sample profile ranged from 2.6-65.1 µm. The addition of printed roughness in the sprouts and rough sprouts group significantly diminished ductility resulting in early strain to failure during tensile testing. Cells adhered and proliferated on discs regardless of roughness group. There was no statistical difference in ALP activity, but qPCR showed that rough groups (sprouts and rough sprouts) had diminished Osteocalcin gene expression at week 2 and 4. The ECM in the rough groups was more resistant to repeated washes and was more extensive with SEM. DISCUSSION/SIGNIFICANCE OF IMPACT: Printing roughness diminished mechanical properties without clear benefit to cell growth. Roughness features were on mesoscale, unlike samples in literature on microscale that increase cell activity. Printed topography may aid in implant fixation and not osseous integration as hypothesized. CONFLICT OF INTEREST DESCRIPTION: Dr. Samual Adams, Dr. Ken Gall and Cambre Kelly own stock and/or stock options in restor3d, Inc.

scholarly journals Influence of Topography on 3D printed Titanium Foot and Ankle Implants

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0001
Author(s):  
Bijan Abar ◽  
Cambre N. Kelly ◽  
Nicholas B. Allen ◽  
Helena Barber ◽  
Alexander P. Kelly ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Testing ◽  
Cellular Proliferation ◽  
Quantitative Polymerase Chain Reaction ◽  
Biological Properties ◽  
Titanium Implants ◽  
Foot And Ankle ◽  
Cell Viability Assay ◽  
Osseous Integration ◽  
3D Printed

Category: Basic Sciences/Biologics; Ankle; Trauma Introduction/Purpose Foot and ankle etiologies such as traumatic fractures, Charcot Arthropathy, nonunion after high risk arthrodesis and infectious debridement can result in critical sized bone defect (CSD). CSD is defined as bone loss greater than 1-2 cm in length or greater than 50% loss in circumference of bone. CSD remain a significant challenge in Orthopaedics. Custom 3D printed porous Titanium implants are currently being implemented when allograft is not an option. However, in a subset of cases, Titanium implants need to be removed due to infection or poor osseous integration where surrounding bone does not grow onto or through the scaffold. There is no one clear reason for poor osseous integration. This study explores effects of 3D printed topography on mechanical and biological properties. Methods: Titanium dog bones and discs were printed via laser powder bed fusion. Roughness groups were polished, blasted, as built, sprouts and rough sprouts. Roughness was measured with line measurement using a confocal microscope. To assess mechanical properties, tensile testing of samples from each roughness group produced stress strain curves. MC3T3 preosteoblast were seeded on discs. Samples were analyzed at 0, 2, and 4 weeks. A cell viability assay and confocal florescent microscopy assessed cell growth. Alkaline Phosphatase (ALP) assay and Quantitative Polymerase Chain Reaction (qPCR) examined cell differentiation. Extracellular matrix (ECM) was stained for collagen and calcium. Scanning Electron Microcopy (SEM) was done on sputter coated discs. Results: Rz, maximum peak to valley distance of the sample profile, for the polished, blasted, as built, sprouts and rough sprouts were 2.6, 22.6, 33.0, 41.4 and 65.1 µm respectively. The addition of printed roughness in the sprouts and rough sprouts group significantly diminished ductility resulting in early strain to failure during tensile testing. Cells adhered and proliferated on discs regardless of roughness group. There was no statically difference in ALP activity, but qPCR showed that rough groups (sprouts and rough sprouts) had diminished Osteocalcin gene expression at week 2 and 4. The ECM observed with SEM in the rough groups was more resistant to repeated washes and was more extensive compared to the less rough groups. Conclusion: The addition of 3D printed artificial roughness leads to inferior mechanical properties and confers no clear benefit regarding cellular proliferation. Printed topography increases the initiation of fractures resulting in diminished tensile strength and ductility. Concurrently, the resolution of LBF is not fine enough at this time to create surface features that enhance cell behavior. Therefore, data in this study suggest that artificially printing roughness is not an effective strategy to enhance osseous integration into Titanium implants for critical sized defects.

scholarly journals Elastomeric Electrospun Scaffolds of a Biodegradable Aliphatic Copolyester Containing PEG-Like Sequences for Dynamic Culture of Human Endothelial Cells

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1620
Author(s):  
Luca Fusaro ◽  
Chiara Gualandi ◽  
Diego Antonioli ◽  
Michelina Soccio ◽  
Anna Liguori ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Vascular Tissue ◽  
Mechanical Performance ◽  
Thrombus Formation ◽  
Cell Activity ◽  
Mechanical Tests ◽  
Cyclic Stretch ◽  
Biological Characterization ◽  
The Right

In the field of artificial prostheses for damaged vessel replacement, polymeric scaffolds showing the right combination of mechanical performance, biocompatibility, and biodegradability are still demanded. In the present work, poly(butylene-co-triethylene trans-1,4-cyclohexanedicarboxylate), a biodegradable random aliphatic copolyester, has been synthesized and electrospun in form of aligned and random fibers properly designed for vascular applications. The obtained materials were analyzed through tensile and dynamic-mechanical tests, the latter performed under conditions simulating the mechanical contraction of vascular tissue. Furthermore, the in vitro biological characterization, in terms of hemocompatibility and cytocompatibility in static and dynamic conditions, was also carried out. The mechanical properties of the investigated scaffolds fit within the range of physiological properties for medium- and small-caliber blood vessels, and the aligned scaffolds displayed a strain-stiffening behavior typical of the blood vessels. Furthermore, all the produced scaffolds showed constant storage and loss moduli in the investigated timeframe (24 h), demonstrating the stability of the scaffolds under the applied conditions of mechanical deformation. The biological characterization highlighted that the mats showed high hemocompatibility and low probability of thrombus formation; finally, the cytocompatibility tests demonstrated that cyclic stretch of electrospun fibers increased endothelial cell activity and proliferation, in particular on aligned scaffolds.

scholarly journals miR-320a/SP1 negative reciprocal interaction contributes to cell growth and invasion in colorectal cancer

2020 ◽  
Author(s):  
Wenjing Zhang ◽  
Haitao Yang ◽  
Zhongqiu Wang ◽  
Yanting Wu ◽  
Jingzhai Wang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Growth ◽  
Quantitative Polymerase Chain Reaction ◽  
Luciferase Reporter ◽  
Inhibitory Effects ◽  
Oncogenic Signaling ◽  
Reciprocal Interaction ◽  
Immunoblotting Assay

Abstract Background: It has demonstrated that transcription factors (TFs) could be engaged reciprocal regulative circuits with some miRNAs to maintain the cellular homeostasis. Disequilibrium of the reciprocities by certain tumor-related stimuli, may give rise to deregulation of downstream cellular signaling pathways, thus promoting malignant phenotypes in tumor.Methods: We performed bioinformatics analysis, quantitative polymerase chain reaction (qRT-PCR), immunoblotting, dual-luciferase reporter assay, and a series of functional assays in vitro and in vivo, to describe a novel SP1/miR-320a reciprocal interaction in colorectal cancer (CRC).Results: Firstly, we found that miR-320a was statistically downregulated in CRC tissues and cell lines. Consistent with findings in other cancers, miR-320a exhibited inhibitory effects on cell growth and invasion of CRC in vitro and in vivo. Moreover, we identified Specificity Protein 1 (SP1), a well-known transcription factor, as a target gene of miR-320a, and ectopic SP1 expression partly abolished miR-320a-induced inhibitory effects. Reversely, we confirmed SP1 to interact with miR-320a promoter thus leading to depression of miR-320a. It hence illustrated a double-negative feedback loop engaging miR-320a with SP1. Additionally, on the basis that SP1 promoted MACC1 transcription, we by immunoblotting assay dissect that, the oncogenic signaling MACC1/MET was inactivated in the context of miR-320a-induced SP1 downregulation. Conclusion: Taken together, our study newly describes the miR-320a/SP1 negative reciprocal interaction contributes to cell growth and invasion in CRC, through modulating MACC1/MET signaling pathway.

scholarly journals Flexicaulin A, An ent-Kaurane Diterpenoid, Activates p21 and Inhibits the Proliferation of Colorectal Carcinoma Cells through a Non-Apoptotic Mechanism

2019 ◽  
Vol 20 (8) ◽  
pp. 1917 ◽  
Author(s):  
Yixuan Xia ◽  
Chu Shing Lam ◽  
Wanfei Li ◽  
Md. Shahid Sarwar ◽  
Kanglun Liu ◽  
...  
Keyword(s):  
Colorectal Carcinoma ◽  
Quantitative Polymerase Chain Reaction ◽  
Carcinoma Cells ◽  
Cell Viability Assay ◽  
Human Carcinoma ◽  
Viability Assay ◽  
Human Colorectal Carcinoma ◽  
Apoptotic Mechanism

Natural products, explicitly medicinal plants, are an important source of inspiration of antitumor drugs, because they contain astounding amounts of small molecules that possess diversifying chemical entities. For instance, Isodon (formerly Rabdosia), a genus of the Lamiaceae (formerly Labiatae) family, has been reported as a rich source of natural diterpenes. In the current study, we evaluated the in vitro anti-proliferative property of flexicaulin A (FA), an Isodon diterpenoid with an ent-kaurane structure, in human carcinoma cells, by means of cell viability assay, flow cytometric assessment, quantitative polymerase chain reaction array, Western blotting analysis, and staining experiments. Subsequently, we validated the in vivo antitumor efficacy of FA in a xenograft mouse model of colorectal carcinoma. From our experimental results, FA appears to be a potent antitumor molecule, since it significantly attenuated the proliferation of human colorectal carcinoma cells in vitro and restricted the growth of corresponsive xenograft tumors in vivo without causing any adverse effects. Regarding its molecular mechanism, FA considerably elevated the expression level of p21 and induced cell cycle arrest in the human colorectal carcinoma cells. While executing a non-apoptotic mechanism, we believe the antitumor potential of FA opens up new horizons for the therapy of colorectal malignancy.

3D-printed chitosan-based scaffolds: An in vitro study of human skin cell growth and an in-vivo wound healing evaluation in experimental diabetes in rats

2018 ◽  
Vol 199 ◽  
pp. 593-602 ◽  
Author(s):  
Claudio Intini ◽  
Lisa Elviri ◽  
Jaydee Cabral ◽  
Sonya Mros ◽  
Carlo Bergonzi ◽  
...  
Keyword(s):  
Wound Healing ◽  
Cell Growth ◽  
Human Skin ◽  
Experimental Diabetes ◽  
In Vitro Study ◽  
Vitro Study ◽  
Skin Cell ◽  
3D Printed

scholarly journals Enhanced osseointegration through direct energy deposition porous coating for cementless orthopedic implant fixation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dong Jin Ryu ◽  
Ara Jung ◽  
Hun Yeong Ban ◽  
Tae Yang Kwak ◽  
Eun Joo Shin ◽  
...  
Keyword(s):  
Energy Deposition ◽  
Cell Activity ◽  
Innovative Technology ◽  
Porous Coating ◽  
In Vitro Test ◽  
Implant Fixation ◽  
Direct Energy Deposition ◽  
Direct Energy ◽  
Joint Implants

AbstractDirect energy deposition (DED) is a newly developed 3D metal printing technique that can be utilized on a porous surface coating of joint implants, however there is still a lack of studies on what advantages DED has over conventional techniques. We conducted a systematic mechanical and biological comparative study of porous coatings prepared using the DED method and other commercially available technologies including titanium plasma spray (TPS), and powder bed fusion (PBF). DED showed higher porosity surface (48.54%) than TPS (21.4%) and PBF (35.91%) with comparable fatigue cycle. At initial cell adhesion, cells on DED and PBF surface appeared to spread well with distinct actin stress fibers through immunofluorescence study. It means that the osteoblasts bind more strongly to the DED and PBF surface. Also, DED surface showed higher cell proliferation (1.27 times higher than TPS and PBF) and osteoblast cell activity (1.28 times higher than PBF) for 2 weeks culture in vitro test. In addition, DED surface showed better bone to implant contact and new bone formation than TPS in in vivo study. DED surface also showed consistently good osseointegration performance throughout the early and late period of osseointegration. Collectively, these results show that the DED coating method is an innovative technology that can be utilized to make cementless joint implants.

In vitro study on cytotoxicity and intracellular formaldehyde concentration changes after exposure to formaldehyde and its derivatives

2013 ◽  
Vol 33 (8) ◽  
pp. 822-830 ◽  
Author(s):  
YJ Ke ◽  
XD Qin ◽  
YC Zhang ◽  
H Li ◽  
R Li ◽  
...  
Keyword(s):  
Cell Growth ◽  
Formic Acid ◽  
Hela Cells ◽  
Cell Activity ◽  
In Vitro Study ◽  
Formaldehyde Concentration ◽  
Low Concentrations ◽  
Formaldehyde Degradation ◽  
Concentration Changes

HeLa cells were exposed to formaldehyde and its metabolic derivatives, methanol, formic acid, and acetaldehyde, to investigate that the toxicity of formaldehyde is not caused by the chemical group. After 1 h of treatment with formaldehyde, mitochondrial assays showed that low concentrations (e.g. 10 μmol/L) of formaldehyde promoted growth of the HeLa cells, while higher concentrations (e.g. ≥62.5 μmol/L) inhibited cell growth; while all four chemicals at a concentration of 125 μmol/L affected cell growth, formaldehyde affected the largest. Reactive oxygen species concentration increased with the concentration of the exposure chemical. The endogenous formaldehyde content increased the most in the formaldehyde group, but in other three groups, it did not increase as the exposure concentration increased. Expression of dehydrogenase (formaldehyde dehydrogenase (FDH)) in the formaldehyde (10.40) and methanol (10.60) groups increased significantly compared with the control (1), while it was similar to the control in formic acid (0.90) and acetaldehyde (1.10) groups. Our results suggest that formaldehyde could affect cell activity and even enter cells. Exposure to formaldehyde changes the endogenous formaldehyde concentration in cells within 24 h, and this induces expression of FDH for formaldehyde degradation to maintain the formaldehyde balance. The toxicity of formaldehyde is not caused by the carbon atoms in the aldehyde, hydroxyl, or carboxyl groups. Formaldehyde is hypothesized to be an important signaling molecule in the regulation of cell growth and maintenance of the endogenous formaldehyde level.

Diving under a Microscope—A New Simple and Versatile In Vitro Diving Device for Fluorescence and Confocal Microscopy Allowing the Controls of Hydrostatic Pressure, Gas Pressures, and Kinetics of Gas Saturation

2013 ◽  
Vol 19 (3) ◽  
pp. 608-616 ◽  
Author(s):  
Qiong Wang ◽  
Marc Belhomme ◽  
François Guerrero ◽  
Aleksandra Mazur ◽  
Kate Lambrechts ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Real Time ◽  
Decompression Sickness ◽  
Fluorescent Microscopy ◽  
Cell Activity ◽  
Real Time Monitoring ◽  
Isolated Cells ◽  
Gas Saturation ◽  
Kinetics Of

AbstractHow underwater diving effects the function of the arterial wall and the activities of endothelial cells is the focus of recent studies on decompression sickness. Here we describe an in vitro diving system constructed to achieve real-time monitoring of cell activity during simulated dives under fluorescent microscopy and confocal microscopy. A 1-mL chamber with sapphire windows on both sides and located on the stage of an inverted microscope was built to allow in vitro diving simulation of isolated cells or arteries in which activities during diving are monitored in real-time via fluorescent microscopy and confocal microscopy. Speed of compression and decompression can range from 20 to 2000 kPa/min, allowing systemic pressure to range up to 6500 kPa. Diving temperature is controlled at 37°C. During air dive simulation oxygen partial pressure is optically monitored. Perfusion speed can range from 0.05 to 10 mL/min. The system can support physiological viability of in vitro samples for real-time monitoring of cellular activity during diving. It allows regulations of pressure, speeds of compression and decompression, temperature, gas saturation, and perfusion speed. It will be a valuable tool for hyperbaric research.

794: Valproic Acid Inhibits Prostate Cancer Cell Growth in Vitro and in Vivo

2006 ◽  
Vol 175 (4S) ◽  
pp. 257-257
Author(s):  
Jennifer Sung ◽  
Qinghua Xia ◽  
Wasim Chowdhury ◽  
Shabana Shabbeer ◽  
Michael Carducci ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Valproic Acid ◽  
Cell Growth ◽  
Cancer Cell ◽  
Prostate Cancer Cell ◽  
Cancer Cell Growth
Sign in / Sign up

Export Citation Format

Share Document