64 research outputs found

    Dissolution and drug release profiles of phosphate glasses doped with high valency oxides

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    This paper investigates phosphate glasses incorporating vanadium and molybdenum oxides for effective management of dissolution and drug release. These glass formulations are found to reduce the rate of dissolution from the glass surfaces. The drug functional groups of vancomycin molecules loaded by immersion showed stronger hydrogen bonding with Vanadium doped glasses and consequently lower rate of drug release over 2 weeks indicating better surface attachment with the drug molecules and slow drug release profiles. This can be explained by the strong adherence of drug molecules to glass surfaces compared with the molybdenum containing glasses (PM5 and PM10). The strong attachment relates to hydrogen bonding between the amino-functional groups of vancomycin and the hydrated P-O-H groups in the glass network. In conclusion, the rate of dissolution of doped glasses and the rate of drug release can be administered to deliver the drug molecules over weeks

    Design and Properties of Novel Substituted Borosilicate Bioactive Glasses and Their Glass-Ceramic Derivatives

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    Three novel borosilicate bioactive glasses (BBGs) of general formula of 0.05Na2O·0.35x·0.20B2O3·0.40SiO2 (molar ratio, where x = MgO or CaO or SrO) were prepared and used to investigate the effect of crystallization on their properties including cytotoxicity. The three postmelt compositions were determined using X-ray fluorescence spectroscopy, and crystallization events were studied using differential thermal analysis and X-ray diffraction. This information was used to determine heat treatments to prepare glass-ceramics by controlled crystallization. X-ray diffraction analysis and Fourier transform infrared spectroscopy showed that, after higher heat treatment temperatures (800–900 °C), borosilicate bioactive glass-ceramics (BBGCs) contained mainly borate and silicate crystalline phases. Specifically, BBG-Mg, BBG-Ca, and BBG-Sr glass-ceramics detected the presence of magnesium silicate-Mg2(SiO3)2 and magnesium borate-Mg2B2O5; wollastonite-2M-CaSiO3 and calcium borate-Ca(BO2)2; and strontium silicate-SrSiO3 and strontium borate-Sr2B2O5, respectively. In vitro cytotoxicity tests were performed using the mouse fibroblast cell line (L929). Glass and glass ceramic at concentrations lower than 50 mg/mL did not exhibit any level of cytotoxicity when compared with the control. However, quantitative evaluation indicated that greater cell growth occurred in the presence of materials with crystalline phases. Control of BBGs crystallization may therefore be used to influence the biocompatibility of these glass-ceramic systems

    Effects of Fe2O3 addition and annealing on the mechanical and dissolution properties of MgO- and CaO-containing phosphate glass fibres for bio-applications

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    This paper investigated the preparation of phosphate glass fibres (PGFs) in the following systems: i) 45P2O5-5B2O3-5Na2O-(29-x)CaO-16MgO-(x)Fe2O3and ii) 45P2O5-5B2O3-5Na2O-24CaO-(21-x)MgO-(x)Fe2O3(where x = 5, 8 and 11 mol%) for biomedical applications. Continuous fibres of 23 ± 1 ÎŒm diameter were prepared via a melt-draw spinning process. Compositions with higher Fe2O3content and higher MgO/CaO ratio required higher melting temperature and longer heating time to achieve glass melts for fibre pulling. The effects of Fe2O3 addition and annealing treatment on mechanical properties and degradation behaviours were also investigated. Adding Fe2O3 was found to increase the tensile strength from 523 ± 63 (Ca-Fe5) to 680 ± 75 MPa (Ca-Fe11), improve the tensile modulus from 72 ± 4 (Ca-Fe5) to 78 ± 3 GPa (Ca-Fe11) and decrease the degradation rate from 4.0 (Mg-Fe5) to 1.9 × 10-6kg m-2s-1(Mg-Fe11). The annealing process reduced the fibre tensile strength by 46% (Ca-Fe5), increased the modulus by 19.6% (Ca-Fe8) and decreased the degradation rate by 89.5% (Mg-Fe11) in comparison to the corresponding as-drawn fibres. Additionally, the annealing process also impeded the formation of precipitate shells and revealed coexistence of the precipitation and the pitting corrosion as fibre degradation behaviours

    An observational study to monitor the efficacy and tolerability of levofloxacin 500 mg once daily for treatment of chronic bacterial prostatitis in Saudi Arabia

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    Introduction: Chronic prostatitis is a common urological problem in men <50-year-old. Untypical uropathogens and an intact blood prostate barrier cause difficulty in using antibiotics to treat the infection. Patients and Methods: In this open-label, observational study, levofloxacin 500 mg was given once daily for 28 days for treatment of chronic prostatitis. The primary efficacy measurement was the disappearance of all pre-treatment symptoms. Efficacy analysis is based on the per protocol population (PPP), all other analyses use the intent to treat (ITT) population. Results: The ITT included 154 men and the PPP included 151 (results are for the ITT unless otherwise indicated). Mean age was 42 ΁ 9 years, common concomitant conditions were diabetes mellitus (7%) and hypertension (5%). All symptoms decreased at day 28. Notably, the rate of dysuria decreased from 86.1% to 10.6%, painful ejaculation from 71% to 2.6% and perineal discomfort from 60.3% to 7.3%. A cure of condition was identified in 58.9%. No treatment failures were reported. Physician-reported adherence to study medication was 96.8%. Conclusion: Levofloxacin appears to be an effective antibiotic for treating symptoms of chronic bacterial prostatitis. Levofloxacin was well-tolerated in this population

    Toughening of Li 2

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    Systematic review of hormone replacement therapy in the infertile man

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    Objectives: To highlight alternative treatment options other than exogenous testosterone administration for hypogonadal men with concomitant infertility or who wish to preserve their fertility potential, as testosterone replacement therapy (TRT) inhibits spermatogenesis, representing a problem for hypogonadal men of reproductive age. Materials and methods: We performed a comprehensive literature review for the years 1978–2017 via PubMed. Also abstracts from major urological/surgical conferences were reviewed. Review was consistent with the Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) criteria. We used Medical Subject Heading terms for the search including ‘testosterone replacement therapy’ or ‘TRT’ and ‘male infertility’. Results: In all, 91 manuscripts were screened and the final number used for the review was 56. All studies included were performed in adults, were written in English and had an abstract available. Conclusions: Exogenous testosterone inhibits spermatogenesis. Hypogonadal men wanting to preserve their fertility and at the same time benefiting from TRT effects can be prescribed selective oestrogen receptor modulators or testosterone plus low-dose human chorionic gonadotrophin (hCG). Patients treated for infertility with hypogonadotrophic hypogonadism can be prescribed hCG alone at first followed by or in combination from the start with follicle-stimulating hormone preparations. Keywords: Gonadotrophins, Hypogonadism, Infertility, Systematic review, Testosterone therap
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