Development of a Novel Bioactive Glass Suitable for Osteosarcoma-Related Bone Grafts

In this study, zinc borate-based glasses with increasing gallium content (0, 2.5, 5, 10, and 15 wt % Ga) were synthesized and their effect on the viability and proliferation of preosteoblasts and osteosarcoma cancer cells were investigated. Methyl thiazolyl tetrazolium (MTT) cell viability assays using glass degradation extracts revealed that the extracts from glasses with lower Ga contents could enhance the viability of preosteoblasts, while extracts from the glass composition with 15 wt % Ga caused statistically significant reduction of their viability. MTT cell viability assays using the extracts and osteosarcoma cells showed that only extracts from the glass composition with 5 wt % Ga (G3) did not cause a statistically significant increase in the viability of cancer cells for all degradation periods (1 day, 7 days, and 28 days). G3 was selected as the most suitable composition for the osteosarcoma-related graft operations as it could improve the viability of preosteoblasts without increasing the viability of cancer cells. The viability of preosteoblasts and osteosarcoma cells in contact with the glass powders were also investigated using MTT assays. The results showed that the G3 powders could enhance the viability of preosteoblasts while decreasing the viability of osteosarcoma cells. Finally, live/dead assays revealed that suppression of proliferation appeared to be the mechanism causing the observed reductions in the viability of osteosarcoma cells exposed to G3 powders. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1186–1193, 2018

A Novel Tantalum-Containing Bioglass. Part II. Development of a Bioadhesive for Sternal Fixation and Repair

With over a million median sternotomy surgeries performed worldwide every year, sternal wound complications have posed a serious risk to the affected patients. A rigid therapeutic sternal fixation device has therefore become a necessity. In this work, the incorporation of up to 0.5 mol% of tantalum pentoxide (Ta2O5), in exchange for zinc oxide (ZnO), into the SiO2-ZnO-CaO-SrO-P2O5 glass system is presented. The effect of Ta incorporation on the physical, chemical and biological properties of the glass polyalkenoate cements (GPCs) prepared from them have been presented in this manuscript. The data obtained have confirmed that Ta2O5 incorporation into the reference glass system results in increased working times, radiopacity, ion solubility, and long-term mechanical stability. The formulated glass systems have also shown clear antibacterial and antifungal activity against both Gram-negative (Escherichia coli) and Gram-positive prokaryotes (Staphylococcus aureus and Streptococcus epidermidis), as well as eukaryotes (Fusarium solani). Cytotoxicity testing showed that Ta incorporation results in no toxicity effect and may simulate osseo-integration when tested in animal models. These new metallic-containing biomaterial adhesives have been developed for sternal fixation and repair. As a permanent implant, the formulated adhesives can be used in conjunction with sternal cable ties to offer optimal fixation for patients and reduce post-operative complications such as bacterial infection and pain from micro-motion

Personal Inner Values – A Key to Effective Face-to-Face Business Communication

Effective face-to-face oral communication is crucial for organizational performance. Managers must communicate effectively with their subordinates, their peers and superiors to link organizational direction to those at all levels of the organization. In addition, face-to-face oral communications are fundamental to the messaging process between business entities, whether a person is acting for oneself or representing his/her company. Face-to-face oral communication that builds empathic trust and mutual confidence is essential in business, especially in light of the recent “crisis in trust” caused by the 2008 financial market “meltdown” and the widely publicized ethical failures in business that have occurred in the past decade. This need is now being successfully addressed and taught to business executives using the neuro-scientifically based technique of compassionate communication, in which two or more people speak slowly and briefly as they remain in a deep state of relaxation and nonjudgmental attentiveness. The twelve components of compassionate communication are reviewed along with the supporting research of earlier studies, with emphasis on a unique inner values exercise that appears to be a key to its successful use in business situations

Comparative Evaluation of Two Glass Polyalkenoate Cements: An in Vivo Pilot Study using a Sheep Model

Poly(methyl methacrylate) (PMMA) is used to manage bone loss in revision total knee arthroplasty (rTKA). However, the application of PMMA has been associated with complications such as volumetric shrinkage, necrosis, wear debris, and loosening. Glass polyalkenoate cements (GPCs) have potential bone cementation applications. Unlike PMMA, GPC does not undergo volumetric shrinkage, adheres chemically to bone, and does not undergo an exothermic setting reaction. In this study, two different compositions of GPCs (GPCA and GPCB), based on the patented glass system SiO2-CaO-SrO-P2O5-Ta2O5, were investigated. Working and setting times, pH, ion release, compressive strength, and cytotoxicity of each composition were assessed, and based on the results of these tests, three sets of samples from GPCA were implanted into the distal femur and proximal tibia of three sheep (alongside PMMA as control). Clinical CT scans and micro-CT images obtained at 0, 6, and 12 weeks revealed the varied radiological responses of sheep bone to GPCA. One GPCA sample (implanted in the sheep for 12 weeks) was characterized with no bone resorption. Furthermore, a continuous bone–cement interface was observed in the CT images of this sample. The other implanted GPCA showed a thin radiolucent border at six weeks, indicating some bone resorption occurred. The third sample showed extensive bone resorption at both six and 12 weeks. Possible speculative factors that might be involved in the varied response can be: excessive Zn2+ ion release, low pH, mixing variability, and difficulty in inserting the samples into different parts of the sheep bone

Titanium addition influences antibacterial activity of bioactive glass coatings on metallic implants

© 2017 The Authors In an attempt to combat the possibility of bacterial infection and insufficient bone growth around metallic, surgical implants, bioactive glasses may be employed as coatings. In this work, silica-based and borate-based glass series were synthesized for this purpose and subsequently characterized in terms of antibacterial behavior, solubility and cytotoxicity. Borate-based glasses were found to exhibit significantly superior antibacterial properties and increased solubility compared to their silica-based counterparts, with BRT0 and BRT3 (borate-based glasses with 0 and 15 mol% of titanium dioxide incorporated, respectively) outperforming the remainder of the glasses, both borate and silicate based, in these respects. Atomic Absorption Spectroscopy confirmed the release of zinc ions (Zn2+), which has been linked to the antibacterial abilities of glasses SRT0, BRT0 and BRT3, with inhibition effectively achieved at concentrations lower than 0.7 ppm. In vitro cytotoxicity studies using MC3T3-E1 osteoblasts confirmed that cell proliferation was affected by all glasses in this study, with decreased proliferation attributed to a faster release of sodium ions over calcium ions in both glass series, factor known to slow cell proliferation in vitro

Effects of an 8-week meditation program on mood and anxiety in patients with memory loss.

Abstract Background: This study assesses changes in mood and anxiety in a cohort of subjects with memory loss who participated in an 8-week Kirtan Kriya meditation program. Perceived spirituality also was assessed. Previous reports from this cohort showed changes in cognitive function and cerebral blood flow (CBF). The purpose of this analysis was to assess outcome measures of mood and affect, and also spirituality, and to determine whether or not results correlated with changes in CBF. Methods: Fifteen (15) subjects (mean age 62±7 years) with memory problems were enrolled in an 8-week meditation program. Before and after the 8-week meditation, subjects were given a battery of neuropsychologic tests as well as measures of mood, anxiety, and spirituality. In addition, they underwent single photon emission computed tomography scans before and after the program. A region-of-interest template obtained counts in several brain structures that could also be compared to the results from the affect and spirituality measures. Results: The meditation training program resulted in notable improvement trends in mood, anxiety, tension, and fatigue, with some parameters reaching statistical significance. All major trends correlated with changes in CBF. There were nonsignificant trends in spirituality scores that did not correlate with changes in CBF. Conclusions: An 8-week, 12 minute a day meditation program in patients with memory loss was associated with positive changes in mood, anxiety, and other neuropsychologic parameters, and these changes correlated with changes in CBF. A larger-scale study is needed to confirm these findings and better elucidate mechanisms of change

Effect of TiO2 Doping on Degradation Rate, Microstructure and Strength of Borate Bioactive Glass Scaffolds

A titanium-containing borate glass series based on the system (52-X) B2O3–12CaO–6P2O5–14Na2O–16ZnO-XTiO2 with X varying from 0, 5 and 15 mol% of TiO2 incorporated, identified as BRT0, BRT1 and BRT3, respectively, were used in this study. Scaffolds (pore sizes, 165–230 μm and porosity, 53.51–69.51%) were prepared using a polymer foam replication technique. BRT3 scaffolds exhibited higher compressive strength (7.16 ± 0.22 MPa) when compared to BRT0 (6.02 ± 0.47 MPa) and BRT1 (5.65 ± 0.28 MPa) scaffolds with lower, or no, TiO2 content. The solubility of the scaffolds decreased as the TiO2 content increased up to 15 mol% when samples of each scaffold were immersed in DI water and the pH of all these extracts went up from 7.0 to 8.5 in 30 days. The cumulative ion release from the scaffolds showed significant difference with respect to TiO2 content; addition of 5 mol% TiO2 at the expense of borate (B2O3) decreased the ion release remarkably. Furthermore, it was found that for all three scaffolds, cumulative ion release increased with incubation time. The results indicate that the degradation rates and compressive strengths of borate bioactive glass scaffolds could be controlled by varying the amount of TiO2 incorporated, confirming their potential as scaffolds in TKA and rTKA

The role of poly(methyl methacrylate) in management of bone loss and infection in revision total knee arthroplasty: A review

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). Poly(methyl methacrylate) (PMMA) is widely used in joint arthroplasty to secure an implant to the host bone. Complications including fracture, bone loss and infection might cause failure of total knee arthroplasty (TKA), resulting in the need for revision total knee arthroplasty (rTKA). The goals of this paper are: (1) to identify the most common complications, outside of sepsis, arising from the application of PMMA following rTKA, (2) to discuss the current applications and drawbacks of employing PMMA in managing bone loss, (3) to review the role of PMMA in addressing bone infection following complications in rTKA. Papers published between 1970 to 2018 have been considered through searching in Springer, Google Scholar, IEEE Xplore, Engineering village, PubMed and weblinks. This review considers the use of PMMA as both a bone void filler and as a spacer material in two-stage revision. To manage bone loss, PMMA is widely used to fill peripheral bone defects whose depth is less than 5 mm and covers less than 50% of the bone surface. Treatment of bone infections with PMMA is mainly for two-stage rTKA where antibiotic-loaded PMMA is inserted as a spacer. This review also shows that using antibiotic-loaded PMMA might cause complications such as toxicity to surrounding tissue, incomplete antibiotic agent release from the PMMA, roughness and bacterial colonization on the surface of PMMA. Although PMMA is the only commercial bone cement used in rTKA, there are concerns associated with using PMMA following rTKA. More research and clinical studies are needed to address these complications

Cerebral blood flow differences between long-term meditators and non-meditators,”

a b s t r a c t We have studied a number of long-term meditators in previous studies. The purpose of this study was to determine if there are differences in baseline brain function of experienced meditators compared to non-meditators. All subjects were recruited as part of an ongoing study of different meditation practices. We evaluated 12 advanced meditators and 14 nonmeditators with cerebral blood flow (CBF) SPECT imaging at rest. Images were analyzed with both region of interest and statistical parametric mapping. The CBF of long-term meditators was significantly higher (p < .05) compared to non-meditators in the prefrontal cortex, parietal cortex, thalamus, putamen, caudate, and midbrain. There was also a significant difference in the thalamic laterality with long-term meditators having greater asymmetry. The observed changes associated with long-term meditation appear in structures that underlie the attention network and also those that relate to emotion and autonomic function

The 25th Anniversary of the Baby Doe Rules: Perspectives from the Fields of Law, Health Care, Ethics, and Disability Policy

A highly publicized and controversial case involving the withholding of medical treatment from a “Baby Doe” with Down syndrome gave rise in 1984 to the federal law known as the Baby Doe Rules, which went into effect the following year. The law conditions the grant of federal funds for any state’s child protective services program on the state’s assurance that it can respond to reports of medical neglect, which may include the withholding of medical treatment from disabled infants with life-threatening conditions. Leading scholars and practitioners from the fields of health care, law, ethics, and disability policy who are experts in the field of neonatal medicine and decision-making involving very premature and other medically at-risk infants gathered to provide thoughtful commentary and debate on the occasion of the 25th Anniversary of the Baby Doe Rules. The Georgia State University Law Review will publish a symposium volume on the topic in Fall 2009