Browsing by Author "Berman, Alycia"

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    Electrochemical Characteristics of AZ31 Magnesium Alloys with Microarc Oxidation Coating
    (Office of the Vice Chancellor for Research, 2013-04-05) Berman, Alycia; Zhang, Weijie; Zhang, Hanying; Hu, Xinyao
    When considering implantable biomaterials, one possible solution that has arisen in recent years is the use of magnesium alloys due to their excellent mechanical properties. Magnesium alloys have many properties comparable to bone, including strength-to-weight ratio, density, and yield strength. For those reasons, magnesium alloys have been viewed as a promising biomaterial. Unfortunately, magnesium alloys are also prone to corrosion attack. To decrease the corrosion, studies have been taken to find appropriate coatings. One possibility is microarc oxidation (MAO) coating. However, studies have yet to be conducted to determine the corrosion of magnesium alloys with MAO coating. In this study, both MAO-coated and uncoated magnesium alloys will be placed in 0.9% saline solution and simulated body fluid and a time study will be conducted. The corrosion properties will be measured through use of a computer-generated Tafel curve, as well as through optical microscopy of the corrosion over the course of time.When considering implantable biomaterials, one possible solution that has arisen in recent years is the use of magnesium alloys due to their excellent mechanical properties. Magnesium alloys have many properties comparable to bone, including strength-to-weight ratio, density, and yield strength. For those reasons, magnesium alloys have been viewed as a promising biomaterial. Unfortunately, magnesium alloys are also prone to corrosion attack. To decrease the corrosion, studies have been taken to find appropriate coatings. One possibility is microarc oxidation (MAO) coating. However, studies have yet to be conducted to determine the corrosion of magnesium alloys with MAO coating. In this study, both MAO-coated and uncoated magnesium alloys will be placed in 0.9% saline solution and simulated body fluid and a time study will be conducted. The corrosion properties will be measured through use of a computer-generated Tafel curve, as well as through optical microscopy of the corrosion over the course of time.
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    Zoledronate and Raloxifene combination therapy enhances material and mechanical properties of diseased mouse bone
    (Elsevier, 2019-10) Powell, Katherine M.; Skaggs, Cayla; Pulliam, Alexis; Berman, Alycia; Allen, Matthew R.; Wallace, Joseph M.; Biomedical Engineering, School of Engineering and Technology
    Current interventions to reduce skeletal fragility are insufficient at enhancing both the quantity and quality of bone when attempting to improve overall mechanical integrity. Bisphosphonates, such as Zoledronate (ZOL), are used to treat a variety of bone disorders by increasing bone mass to decrease fracture risk, but long-term use has been shown in some settings to compromise bone quality. Alternatively, Raloxifene (RAL) has recently been demonstrated to improve tissue quality and overall mechanical properties in a cell-independent manner by binding to collagen and increasing tissue hydration. We hypothesized that a combination of RAL and ZOL would improve mechanical and material properties of bone more than either monotherapy alone by enhancing both quantity and quality. In this study, wildtype (WT) and heterozygous (OIM+/−) male mice from the Osteogenesis Imperfecta (OI) murine model were treated with either RAL, ZOL, or both from 8 weeks to 16 weeks of age. Using the OIM model allows for investigation of therapeutic effects on a quality-based bone disease. Combination treatment resulted in higher trabecular architecture, cortical mechanical properties, and cortical fracture toughness in diseased mouse bone. Two fracture toughness properties, which are direct measures of the tissue's ability to resist the initiation and propagation of a crack, were significantly improved with combination treatment in OIM+/− compared to control. There was no significant effect on fracture toughness with either monotherapy alone in either genotype. Following the mass-based effects of ZOL, trabecular bone volume fraction was significantly higher with combination treatment in both genotypes. Combination treatment resulted in higher ultimate stress in both genotypes. RAL and combination treatment in OIM+/− also increased resilience compared to the control. In conclusion, this study demonstrates the beneficial effects of using combination drug treatments to increase bone mass while simultaneously improving tissue quality, especially to enhance the mechanical integrity of diseased bone. Combination therapies could be a potential method to improve bone health and combat skeletal fragility on both the microscopic and macroscopic levels.
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    Zoledronate and Raloxifene combination therapy enhances material and mechanical properties of diseased mouse bone
    (Elsevier, 2019-10-01) Powell, Katherine M.; Skaggs, Cayla; Pulliam, Alexis; Berman, Alycia; Allen, Matthew R.; Wallace, Joseph M.; Biomedical Engineering, School of Engineering and Technology
    Current interventions to reduce skeletal fragility are insufficient at enhancing both the quantity and quality of bone when attempting to improve overall mechanical integrity. Bisphosphonates, such as Zoledronate (ZOL), are used to treat a variety of bone disorders by increasing bone mass to decrease fracture risk, but long-term use has been shown in some settings to compromise bone quality. Alternatively, Raloxifene (RAL) has recently been demonstrated to improve tissue quality and overall mechanical properties in a cell-independent manner by binding to collagen and increasing tissue hydration. We hypothesized that a combination of RAL and ZOL would improve mechanical and material properties of bone more than either monotherapy alone by enhancing both quantity and quality. In this study, wildtype (WT) and heterozygous (OIM+/−) male mice from the Osteogenesis Imperfecta (OI) murine model were treated with either RAL, ZOL, or both from 8 weeks to 16 weeks of age. Using the OIM model allows for investigation of therapeutic effects on a quality-based bone disease. Combination treatment resulted in higher trabecular architecture, cortical mechanical properties, and cortical fracture toughness in diseased mouse bone. Two fracture toughness properties, which are direct measures of the tissue's ability to resist the initiation and propagation of a crack, were significantly improved with combination treatment in OIM+/− compared to control. There was no significant effect on fracture toughness with either monotherapy alone in either genotype. Following the mass-based effects of ZOL, trabecular bone volume fraction was significantly higher with combination treatment in both genotypes. Combination treatment resulted in higher ultimate stress in both genotypes. RAL and combination treatment in OIM+/− also increased resilience compared to the control. In conclusion, this study demonstrates the beneficial effects of using combination drug treatments to increase bone mass while simultaneously improving tissue quality, especially to enhance the mechanical integrity of diseased bone. Combination therapies could be a potential method to improve bone health and combat skeletal fragility on both the microscopic and macroscopic levels.