Author : Shiva Naseri
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (14 download)
Book Synopsis Highly Reactive Silver Doped Sol-gel-derived Borate Glasses for Wound Healing Applications by : Shiva Naseri
Download or read book Highly Reactive Silver Doped Sol-gel-derived Borate Glasses for Wound Healing Applications written by Shiva Naseri and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Bioactive and soluble glasses exhibit great potential in biomedical applications in both hard and soft tissue engineering. The rate at which these glasses generate a response, or their reactivity, is an important parameter for healing efficacy. Owing to their tetrahedral coordination, silicate-based glasses exhibit slow and incomplete solubility, which limit their application in soft tissue repair. Therefore, there is great interest in developing more soluble and reactive bioactive glass formulations based on the borate network forming oxide, which can be both trigonally and tetrahedrally coordinated. It has been shown that borate-based glasses have higher reactivity than silicate-based glasses attributed to their glass network structure. Limitations in conventional methods such as the lack of accuracy and time-consumption to examine reactivity/bioactivity and surface properties of bioactive and soluble glasses have led to an increased interest in finding and investigating new techniques, such as dynamic vapour sorption (DVS) and inverse gas chromatography (IGC). It was demonstrated that DVS has the ability to measure and predict the bioactivity/reactivity of silicate-, phosphate- and borate- based glasses with various specific surface areas/particle sizes or formulations. It was shown that DVS was able to measure and correlate the vapour isotherm values of melt-quench derived Bioglass® 45S5: (46.1)SiO2-(26.9)CaO-(24.4)Na2O-(2.6)P2O5 (mol %) of three different particle sizes (surface areas) with the reactivity, bioactivity and ions release rates of glasses. Higher surface area led to the higher vapour sorption and reactivity. Additionally, IGC was utilized to examine the surface properties of melt-quench derived phosphate glasses (PGs) doped with both SiO2 and TiO2 (50P2O5-40CaO-xSiO2-(10 − x) TiO2, where x = 7, 5, 3, and 0 mol%). It was shown that IGC was more accurate and sensitive than other conventional techniques such as contact angle measurement in determining the effect of silica content on the surface properties of PGs. In conclusion, this dissertation has assessed the potential complementarity of DVS and IGC in the characterization of aqueous reactivity and surface properties of bioactive and soluble glasses.Moreover, complications in the healing of chronic wounds in patients who are at constant risk of infections have led to a great demand for the development of biomaterial based wound dressing replacement. Borate-based glasses have recently been approved for wound repair which are melt-quench derived, yet borate glasses fabricated through the sol-gel process have the benefits of higher dissolution rate, which could potentially lead to the more rapid wound repair. However, the potential of sol-gel derived borate glasses, in particular, silver doped borate-based glasses (AgBGs) for soft tissue repair has so far not been investigated. In this thesis, anti-bacterial AgBGs in the B2O3Ag2O-CaO-P2O5 system were fabricated through optimization of sol-gel process and glass composition. Silver ion release rate and anti-bacterial activity were correlated and demonstrated dose dependent efficacy against Escherichia coli or Staphylococcus aureus and Pseudomonas aeruginosa bacteria. In addition, AgBGs were systematically examined to determine their effects on cellular functions such as metabolic activity, cell viability and migration through in vitro cell culture of human derived keratinocyte (HaCat) and mouse derived fibroblastic (NIH/3T3) cell lines. It was verified that silver release from AgBGs was not toxic to both cells at lower concentrations (
