scholarly journals Functional Properties of Low-Modulus PMMA Bone Cements Containing Linoleic Acid

2021 ◽  
Vol 12 (1) ◽  
pp. 5
Author(s):  
Céline Robo ◽  
David Wenner ◽  
S. J. Kumari A. Ubhayasekera ◽  
Jöns Hilborn ◽  
Caroline Öhman-Mägi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Linoleic Acid ◽  
Functional Properties ◽  
Setting Time ◽  
Bone Cements ◽  
High Modulus ◽  
Promising Alternative ◽  
High Stiffness ◽  
Screw Augmentation ◽  
Low Modulus

Acrylic bone cements modified with linoleic acid are a promising low-modulus alternative to traditional high-modulus bone cements. However, several key properties remain unexplored, including the effect of autoclave sterilization and the potential use of low-modulus cements in other applications than vertebral augmentation. In this work, we evaluate the effect of sterilization on the structure and stability of linoleic acid, as well as in the handling properties, glass transition temperature, mechanical properties, and screw augmentation potential of low-modulus cement containing the fatty acid. Neither 1H NMR nor SFC-MS/MS analysis showed any detectable differences in autoclaved linoleic acid compared to fresh one. The peak polymerization temperature of the low-modulus cement was much lower (28–30 °C) than that of the high-modulus cement (67 °C), whereas the setting time remained comparable (20–25 min). The Tg of the low-modulus cement was lower (75–78 °C) than that of the high-stiffness cement (103 °C). It was shown that sterilization of linoleic acid by autoclaving did not significantly affect the functional properties of low-modulus PMMA bone cement, making the component suitable for sterile production. Ultimately, the low-modulus cement exhibited handling and mechanical properties that more closely match those of osteoporotic vertebral bone with a screw holding capacity of under 2000 N, making it a promising alternative for use in combination with orthopedic hardware in applications where high-stiffness augmentation materials can result in undesired effects.

ARAMID–NYLON 6.6 HYBRID CORDS AND INVESTIGATION OF THEIR PROPERTIES

2012 ◽  
Vol 85 (2) ◽  
pp. 180-194 ◽  
Author(s):  
Berrin Yilmaz
Keyword(s):  
Mechanical Properties ◽  
Linear Density ◽  
Thermally Stable ◽  
High Modulus ◽  
Synthetic Yarn ◽  
Product Property ◽  
High Fatigue ◽  
High Elongation ◽  
Low Modulus ◽  
Twist Level

Abstract Hybrid cords of two different polyamide yarns, poly(p-phenylene terephthalamide; aramid) and poly(hexamethylene adipamide; nylon 6.6) have been investigated. Aramid is a high-tenacity, high-modulus, low-elongation, and thermally stable yarn material. Nylon 6.6 is a high-elongation, low-modulus, high-fatigue-resistant, and good adhering synthetic yarn. The combination of these two different synthetic yarns enables hybrid cords with a diversified range of mechanical properties. The hybrid cord product property diversification is achieved by proper combination of different cord-forming properties of individual plies, such as linear densities, twist levels, ply numbers, treating conditions, and so forth. The effect of linear densities, twist level of plies, and twist level of cabled cord and ply number on the cord properties and also cord performance have been summarized. Aramid yarn having an 1100 linear density has been combined with nylon 6.6 yarn with a different linear density, ranging from 940 to 2100, to form hybrid cord structures. Twisting of aramid and nylon 6.6 yarns has been kept between 150 and 450 twists per meter, while the ply number of aramid and nylon 6.6 yarns has been varied as one and two plies by keeping the total ply number of the cord as three.

scholarly journals Acrylic Bone Cements Modified with Graphene Oxide: Mechanical, Physical, and Antibacterial Properties

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1773 ◽  
Author(s):  
Mayra Eliana Valencia Zapata ◽  
Lina Marcela Ruiz Rojas ◽  
José Herminsul Mina Hernández ◽  
Johannes Delgado-Ospina ◽  
Carlos David Grande Tovar
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Bacterial Infections ◽  
Setting Time ◽  
Antibacterial Properties ◽  
Physical And Mechanical Properties ◽  
Maximum Temperature ◽  
Bone Cements ◽  
Gram Negative ◽  
Total Joint Replacements

Bacterial infections are a common complication after total joint replacements (TJRs), the treatment of which is usually based on the application of antibiotic-loaded cements; however, owing to the increase in antibiotic-resistant microorganisms, the possibility of studying new antibacterial agents in acrylic bone cements (ABCs) is open. In this study, the antibacterial effect of formulations of ABCs loaded with graphene oxide (GO) between 0 and 0.5 wt.% was evaluated against Gram-positive bacteria: Bacillus cereus and Staphylococcus aureus, and Gram-negative ones: Salmonella enterica and Escherichia coli. It was found that the effect of GO was dependent on the concentration and type of bacteria: GO loadings ≥0.2 wt.% presented total inhibition of Gram-negative bacteria, while GO loadings ≥0.3 wt.% was necessary to achieve the same effect with Gram-positives bacteria. Additionally, the evaluation of some physical and mechanical properties showed that the presence of GO in cement formulations increased wettability by 17%, reduced maximum temperature during polymerization by 19%, increased setting time by 40%, and increased compressive and flexural mechanical properties by up to 17%, all of which are desirable behaviors in ABCs. The formulation of ABC loading with 0.3 wt.% GO showed great potential for use as a bone cement with antibacterial properties.

Acrylic Bone Cements: New Insight and Future Perspective

2017 ◽  
Vol 745 ◽  
pp. 39-49 ◽  
Author(s):  
Simona Cavalu
Keyword(s):  
Mechanical Properties ◽  
Bone Cement ◽  
Bone Growth ◽  
Setting Time ◽  
Ceramic Composites ◽  
Future Perspective ◽  
Bone Cements ◽  
Main Function ◽  
Suture Materials ◽  
Artificial Joint Replacement

The history of acrylic bone cement comprise a long period of time, Sir John Charnley being considered the founder of modern artificial joint replacement, as he started to develop the cementing in the late 1950s. Acrylic bone cements (ACB) are polymer-ceramic composites based on polymethyl metacrylate (PMMA), widely used in orthopaedics as suture materials and fixation devices. The main features of these materials are: 1) biocompatibility and ability to support new bone growth (osteoconductive) and 2) bioactivity (ability to form a calcium phosphate layer on its surface). The main function of the cement is to serve as interfacial phase between the high modulus metallic implant and the bone, thereby assisting to transfer and distribute loads. During years of follow up, cemented prosthesis with acrylic bone cements (ABC) demonstrated a good primary fixation and load distribution between implant and bone, along with the advantage of fast recovery of the patient. However, several problems are still persisting, as the orthopedic acrylic bone cements have to meet several medical requirements, such as low values of maximum cure temperature in order to avoid thermal necrosis of the bone tissue during the setting time, appropriate setting time (so that cement does not cure too fast or too slowly) and high values of compressive strength in order to withstand the compressive loads involved by normal daily activities. Generally, the improvement mechanical properties can be realized in three directions: 1) by searching alternative material to PMMA acrylic bone cements; 2) chemical modification of PMMA; and 3) the reinforcement of PMMA by adding different bioactive particles, antimicrobials, vitamins. The aim of this rewiew is to explore the development of bone cements in the last decade, to highlight the role of bone cement additives with respect to mechanical properties and limitations of polymethylmethacrylate in orthopaedic surgery. The behavior of antibiotic-loaded bone cement is discussed, compared with other alternative additives including nanofillers, together with areas of research that are now open to explore new insights and applications of this well known biomaterial.

scholarly journals Experimental Drillable Magnesium Phosphate Cement Is a Promising Alternative to Conventional Bone Cements

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1925
Author(s):  
Philipp Heilig ◽  
Phoebe Sandner ◽  
Martin Cornelius Jordan ◽  
Rafael Gregor Jakubietz ◽  
Rainer Heribert Meffert ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Phytic Acid ◽  
Mechanical Performance ◽  
Setting Time ◽  
High Strength ◽  
Magnesium Phosphate ◽  
Bone Cements ◽  
Promising Alternative ◽  
Phytic Acid Content ◽  
With Screws

Clinically used mineral bone cements lack high strength values, absorbability and drillability. Therefore, magnesium phosphate cements have recently received increasing attention as they unify a high mechanical performance with presumed degradation in vivo. To obtain a drillable cement formulation, farringtonite (Mg3(PO4)2) and magnesium oxide (MgO) were modified with the setting retardant phytic acid (C6H18O24P6). In a pre-testing series, 13 different compositions of magnesium phosphate cements were analyzed concentrating on the clinical demands for application. Of these 13 composites, two cement formulations with different phytic acid content (22.5 wt% and 25 wt%) were identified to meet clinical demands. Both formulations were evaluated in terms of setting time, injectability, compressive strength, screw pullout tests and biomechanical tests in a clinically relevant fracture model. The cements were used as bone filler of a metaphyseal bone defect alone, and in combination with screws drilled through the cement. Both formulations achieved a setting time of 5 min 30 s and an injectability of 100%. Compressive strength was shown to be ~12–13 MPa and the overall displacement of the reduced fracture was <2 mm with and without screws. Maximum load until reduced fracture failure was ~2600 N for the cements only and ~3800 N for the combination with screws. Two new compositions of magnesium phosphate cements revealed high strength in clinically relevant biomechanical test set-ups and add clinically desired characteristics to its strength such as injectability and drillability.

scholarly journals Photoluminescent Eu3+-Doped Calcium Phosphate Bone Cement and Its Mechanical Properties

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1610 ◽  
Author(s):  
Annemarie Oesterle ◽  
Anne Boehm ◽  
Frank Müller
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Bone Cement ◽  
Setting Time ◽  
Bone Cements ◽  
X Ray ◽  
Novel Approach ◽  
Calcium Phosphate Bone Cement ◽  
Negative Effect ◽  
Healing Processes

Calcium phosphate cements (CPC) are well-established bone replacement materials that have been used in dentistry and orthopedics for more than 25 years. The monitoring of bone cements and the associated healing processes in the human body is difficult and so far has often been achieved using cytotoxic X-ray contrast agent additives. These additives have a negative effect on the mechanical properties and setting time of the bone cement. In this paper, we present a novel approach to prepare contrastive CPC by the incorporation of luminescent Eu3+-doped hydroxyapatite (Eu:HAp) nanoparticles. Eu-doped CPC (Eu:CPC) exhibited enhanced mechanical properties compared to pure CPC. Furthermore, the red photoluminescence of Eu:CPC may allow the observation of CPC-related healing processes without the use of harmful ionizing radiation.

scholarly journals In Vitro and In Vivo Response to Low-Modulus PMMA-Based Bone Cement

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Elin Carlsson ◽  
Gemma Mestres ◽  
Kiatnida Treerattrakoon ◽  
Alejandro López ◽  
Marjam Karlsson Ott ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Immune Cells ◽  
Castor Oil ◽  
In Vitro Cytotoxicity ◽  
Bone Cements ◽  
Human Osteoblast ◽  
Flow Cytometry Analysis ◽  
Low Modulus

The high stiffness of acrylic bone cements has been hypothesized to contribute to the increased number of fractures encountered after vertebroplasty, which has led to the development of low-modulus cements. However, there is no data available on the in vivo biocompatibility of any low-modulus cement. In this study, the in vitro cytotoxicity and in vivo biocompatibility of two types of low-modulus acrylic cements, one modified with castor oil and one with linoleic acid, were evaluated using human osteoblast-like cells and a rodent model, respectively. While the in vitro cytotoxicity appeared somewhat affected by the castor oil and linoleic acid additions, no difference could be found in the in vivo response to these cements in comparison to the base, commercially available cement, in terms of histology and flow cytometry analysis of the presence of immune cells. Furthermore, the in vivo radiopacity of the cements appeared unaltered. While these results are promising, the mechanical behavior of these cements in vivo remains to be investigated.

Autonomous self-healing polyisoprene elastomers with high modulus and good toughness based on the synergy of dynamic ionic crosslinks and highly disordered crystals

2020 ◽  
Vol 11 (41) ◽  
pp. 6549-6558
Author(s):  
Yohei Miwa ◽  
Mayu Yamada ◽  
Yu Shinke ◽  
Shoichi Kutsumizu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Self Healing ◽  
High Modulus ◽  
Disordered Crystals ◽  
Ionic Crosslinks

We designed a novel polyisoprene elastomer with high mechanical properties and autonomous self-healing capability at room temperature facilitated by the coexistence of dynamic ionic crosslinks and crystalline components that slowly reassembled.

scholarly journals Effects of Steel Fiber Percentage and Aspect Ratios on Fresh and Harden Properties of Ultra-High Performance Fiber

2021 ◽  
Vol 2 (3) ◽  
pp. 501-515
Author(s):  
Rajib Kumar Biswas ◽  
Farabi Bin Ahmed ◽  
Md. Ehsanul Haque ◽  
Afra Anam Provasha ◽  
Zahid Hasan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
High Performance ◽  
Steel Fiber ◽  
Setting Time ◽  
Fiber Reinforced Concrete ◽  
Future Research ◽  
Manufacturing Cost ◽  
Aspect Ratios ◽  
High Performance Fiber

Steel fibers and their aspect ratios are important parameters that have significant influence on the mechanical properties of ultrahigh-performance fiber-reinforced concrete (UHPFRC). Steel fiber dosage also significantly contributes to the initial manufacturing cost of UHPFRC. This study presents a comprehensive literature review of the effects of steel fiber percentages and aspect ratios on the setting time, workability, and mechanical properties of UHPFRC. It was evident that (1) an increase in steel fiber dosage and aspect ratio negatively impacted workability, owing to the interlocking between fibers; (2) compressive strength was positively influenced by the steel fiber dosage and aspect ratio; and (3) a faster loading rate significantly improved the mechanical properties. There were also some shortcomings in the measurement method for setting time. Lastly, this research highlights current issues for future research. The findings of the study are useful for practicing engineers to understand the distinctive characteristics of UHPFRC.

scholarly journals Utilization of Solid Waste from Brick Industry and Hydrated Lime in Self-Compacting Cement Pastes

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1109
Author(s):  
Mati Ullah Shah ◽  
Muhammad Usman ◽  
Muhammad Usman Hanif ◽  
Iqra Naseem ◽  
Sara Farooq
Keyword(s):  
Mechanical Properties ◽  
Solid Waste ◽  
Manufacturing Industry ◽  
Setting Time ◽  
Hydrated Lime ◽  
Pozzolanic Reaction ◽  
Early Age ◽  
Cement Pastes ◽  
Brick Powder ◽  
High Degree

The huge amount of solid waste from the brick manufacturing industry can be used as a cement replacement. However, replacement exceeding 10% causes a reduction in strength due to the slowing of the pozzolanic reaction. Therefore, in this study, the pozzolanic potential of brick waste is enhanced using ultrafine brick powder with hydrated lime (HL). A total of six self-compacting paste mixes were studied. HL 2.5% by weight of binder was added in two formulations: 10% and 20% of waste burnt brick powder (WBBP), to activate the pozzolanic reaction. An increase in the water demand and setting time was observed by increasing the replacement percentage of WBBP. It was found that the mechanical properties of mixes containing 5% and 10% WBBP performed better than the control mix, while the mechanical properties of the mixes containing 20% WBBP were found to be almost equal to the control mix at 90 days. The addition of HL enhanced the early-age strength. Furthermore, WBBP formulations endorsed improvements in both durability and rheological properties, complemented by reduced early-age shrinkage. Overall, it was found that brick waste in ultrafine size has a very high degree of pozzolanic potential and can be effectively utilized as a supplementary cementitious material.

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