Effects of annealing on density, glass transition temperature and structure of tellurite, silicate and borate glasses

Kaur, Amarjot; Khanna, Atul; Kaur, Amandeep; Hirdesh,; Gónzález-Barriuso, Marina; González, F.

doi:10.1016/j.jnoncrysol.2018.08.035

Cited by 17 publications

(7 citation statements)

References 53 publications

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“…The increase in the T g may be due to thermal annealing at the higher temperature. This phenomenon has been observed in other solid materials, even when the storage temperature was below the T g 25‐27 . XRD data (Figure 4 and Figure S1) showed that all the phage powders stored at <25°C/15% RH remained partially crystalline with diffraction peaks from crystalline leucine at 6°, 19°, and 34° 1,2 .…”

Section: Resultssupporting

confidence: 65%

Inhalable bacteriophage powders: Glass transition temperature and bioactivity stabilization

Chang

Kwok

Khanal

et al. 2020

Bioengineering & Transla Med

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Recent heightened interest in inhaled bacteriophage (phage) therapy for combating antibacterial resistance in pulmonary infections has led to the development of phage powder formulations. Although phages have been successfully bioengineered into inhalable powders with preserved bioactivity, the stabilization mechanism is yet unknown. This paper reports the first study investigating the stabilization mechanism for phages in these powders. Proteins and other biologics are known to be preserved in dry state within a glassy sugar matrix at storage temperatures (T s ) at least~50 C below the glass transition temperature (T g ). This is because at (T g − T s ) >50 C, molecules are sufficiently immobilized with reduced reactivity. We hypothesized that this glass stabilization mechanism may also be applicable to phages comprising mostly of proteins. In this study, spray dried powders of Pseudomonas phage PEV20 containing lactose and leucine as excipients were stored at 5, 25 or 50 C and 15 or 33% relative humidity (RH), followed by assessment of bioactivity (PEV20 stability) and physical properties. PEV20 was stable with negligible titer loss after storage at 5 C/15% RH for 250 days, while storage at 33% RH caused increased titer losses of 1 log 10 and 3 log 10 at 5 and 25 C, respectively. The plasticizing effect of water at 33% RH lowered the T g by 30 C, thus narrowing the gap between T s and T g to 19-28 C, which was insufficient for glass stabilization. In contrast, the (T g − T s ) values were higher (range, 46-65 C) under the drier condition of 15% RH, resulting in the improved stability which corroborated with the vitrification hypothesis. Furthermore, phage remained stable (≤1 log 10 ) when the (T g − T s ) value lay between 26-48 C, but became inactivated as the value fell below 20 C. In conclusion, this study demonstrated that phage can be sufficiently stabilized in spray dried powders by keeping Abbreviations: DSC, differential scanning calorimetry; RH, relative humidity; TGA, thermal gravimetric analysis.; XRD, X-ray diffraction pattern.

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Section: Resultssupporting

confidence: 65%

Inhalable bacteriophage powders: Glass transition temperature and bioactivity stabilization

Chang

Kwok

Khanal

et al. 2020

Bioengineering & Transla Med

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“…They are easily reduced to powder. For the first option, the liquid mixture is poured into a mold preheated at Tg (glass transition temperature) and then placed in an oven at Tg for 1 h. This last step allows to shape the liquid mixture while limiting the presence of intrinsic mechanical constraints inside the glass [54]. The size and shape of the mold used determine the macroscopicity of the glass.…”

Section: Shaping By Quenching Fusion Processmentioning

confidence: 99%

The Challenge of 3D Bioprinting of Composite Natural Polymers PLA/Bioglass: Trends and Benefits in Cleft Palate Surgery

et al. 2021

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Cleft lip and palate is the fourth most common congenital malformation. Its prevalence is about 1 in 750 to 1 in 2000 live births. The consequences of this malformation are major: maxillary growth deficit, unaesthetic appearance, phonation disorders, difficulty in eating, and psycho-social disorders. Cleft palate repair establishes the division between the oral and nasal cavities. The alveolar bone graft is a key step. Different sites of autogenous bone harvesting are used, the most common being the iliac crest. Nevertheless, the large number of complications associated with harvesting has led to the use of substitute biomaterials. Bioactive glasses, discovered in 1969, are a group of synthetic silica-based materials with bone-bonding properties. Although 45S5 granular composition is commonly used in bone surgery to repair critical defects, it is only rarely used in the repair of cleft palates because this galenic form is only moderately adapted. However, advances in bone tissue engineering allow the shaping of three-dimensional scaffolds, which support colonization by host cells. Recent advances in computer-aided design/computer-aided manufacturing (CAD/CAM) have even led to the 3D printing of scaffolds combining 45S5 bioglass with a natural and biocompatible poly-lactic acid matrix. The shape of the parts is customized and adapted to the particular shape of the critical bone defects. The objective of this literature review is to highlight the particularities of alveolar defects subsequent to facial clefts, then to detail the characteristics of the materials and technologies used to elaborate 3D matrices by bioprinting. Finally, we will explore research directions regarding their use in reconstructive surgery of cleft palates.

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“…In TeO 4 unit, four oxygen atoms are coordinated with one tellurium atom to form a trigonal bipyramid (tbp) with one of the equatorial oxygen positions unoccupied [5,16,23,24]. In the trigonal pyramid structure, there are two bridging oxygen sites and one non-bridging oxygen (NBO) which is a Te = O double bond [5,16,25]. This is a unique structural characteristic of TeO 2 glass, distinct from other network-forming glasses; e.g., silicates, phosphates and germanates in which only the NBO and bridging oxygen exist as a part of the structural unit [5,16,[26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Influence of barium oxide on glass-forming ability and glass stability of the tellurite–phosphate oxide glasses

Leśniak

Szal

Starzyk

et al. 2019

J Therm Anal Calorim

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The effect of BaO content on the glass-forming ability, glass stability and structure of tellurite-phosphate oxide glasses in the 70TeO 2-10P 2 O 5-(20-x)ZnO-xBaO (x = 0, 5 and 10 mol%) system has been discussed. From the differential scanning calorimetry, the glass transition (Tg), crystallization (Tc) and the melting (Tm) temperatures were estimated. The decrease in reduced glass transition temperature (Tr g) and glass-forming tendency parameter (K h (Tc 1)) with addition and increasing BaO caused a decrease in the glass-forming ability of glasses. It was also found that the thermal stability of these glasses against crystallization decreased with increase in BaO concentration into chemical composition of base glass, i.e., glass without barium oxide. The FTIR spectra were measured to understand the structure of the obtained tellurite-phosphate oxide glasses. The results have shown that phosphorous and tellurium ions were taken part in the formation of the glass network of the studied glasses. The addition of BaO caused significant changes in the FTIR spectra of glasses. More and more TeO 3 and TeO 3?d units and PO 4 2groups (Q 1 units) were created when the BaO was added into the chemical composition of the base glass. Increasing barium ions content into the chemical composition of glasses caused depolymerization of the tellurite-phosphate oxide glass network. Keywords Tellurite-phosphate oxide glasses Á BaO Á Glass-forming stability Á Glass stability Á Structure

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Effects of annealing on density, glass transition temperature and structure of tellurite, silicate and borate glasses

Cited by 17 publications

References 53 publications

Inhalable bacteriophage powders: Glass transition temperature and bioactivity stabilization

Inhalable bacteriophage powders: Glass transition temperature and bioactivity stabilization

The Challenge of 3D Bioprinting of Composite Natural Polymers PLA/Bioglass: Trends and Benefits in Cleft Palate Surgery

Influence of barium oxide on glass-forming ability and glass stability of the tellurite–phosphate oxide glasses

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