Performance of Bioactive Hydroxyapatite Coating after Soaking in Simulated Body Fluid

2010 ◽  
Vol 93-94 ◽  
pp. 59-62 ◽  
Author(s):  
Waraporn Suvannapruk ◽  
Kitiya Wasoontararat ◽  
Jintamai Suwanprateeb

In this study, in vitro acellular bioactivity and tensile bonding strength of hydroxyapatite (HA) coating synthesized by sol-gel technique after long-term storage in simulated body fluid (SBF) for up to 32 days were studied. After soaking in SBF, it was observed that new bone-like apatite layer was formed on the coating indicating the bioactive nature. Bonding strength of sol-gel coated rods was found to decrease with soaking times, from 55 to 30 MPa. In comparison to adhesive bonded titanium rods which were used as control specimens, the values were found to be equal or even greater in certain soaking periods. Debonding at adhesive-titanium interface was the failure mode indicating that the coating is still intact. Therefore, it could be concluded that this sol-gel coating is bioactive and the coating adhesion to substrate is sufficiently strong.

2016 ◽  
Author(s):  
S. A. Syed Nuzul Fadzli ◽  
S. Roslinda ◽  
Firuz Zainuddin ◽  
Hamisah Ismail

2016 ◽  
Vol 9 (3) ◽  
pp. 379-388 ◽  
Author(s):  
N. De Clercq ◽  
G. Vlaemynck ◽  
E. Van Pamel ◽  
D. Colman ◽  
M. Heyndrickx ◽  
...  

Penicillium expansum is the principal cause of blue mould rot and associated production of patulin, a weak mycotoxin, in apples worldwide. P. expansum growth and patulin production is observed during improper or long-term storage of apples. We have investigated the extent to which each successive step during long-term storage contributes to patulin production in various P. expansum isolates. Fungal isolates collected on apples from several Belgian orchards/industries were identified to species level. Random amplification of polymorphic DNA (RAPD) analysis and β-tubulin gene sequencing identified P. expansum and Penicillium solitum as the most prevalent Penicillium species associated with Belgian apples. All 27 P. expansum isolates and eight reference strains were characterised for their patulin production capacity on apple puree agar medium for five days under classical constant temperature and atmosphere conditions. Under these conditions, a large range of patulin production levels was observed. Based on this phenotypic diversity, five P. expansum isolates and one reference strain were selected for in vitro investigation of patulin production under representative conditions in each step of long-term apple storage. Patulin accumulation seemed highly strain dependent and no significant differences between the storage steps were observed. The results also indicated that a high spore inoculum may lead to a strong patulin accumulation even at cold temperatures (1 °C) combined with controlled atmosphere (CA) (3% O2, 1% CO2), suggesting that future control strategies may benefit from considering the duration of storage under CA conditions as well as duration of deck storage.


2005 ◽  
Vol 480-481 ◽  
pp. 21-26 ◽  
Author(s):  
L.J. Skipper ◽  
F.E. Sowrey ◽  
D.M. Pickup ◽  
R.J. Newport ◽  
K.O. Drake ◽  
...  

The formation of a carbonate-containing hydroxyapatite, HCAp, layer on bioactive calcium silicate sol-gel glass of the formula (CaO)0.3(SiO2)0.7 has been studied in-vitro in Simulated Body Fluid (SBF). Extended X-ray Absorption Fine Structure (EXAFS), X-ray Absorption Near Edge Structure (XANES), X-ray diffraction (XRD), and solid state nuclear magnetic resonance (NMR) measurements have been performed with results showing the formation of a significantly amorphous HCAp layer after less than 5 hours in solution.


2011 ◽  
Vol 7 (2) ◽  
pp. 829-840 ◽  
Author(s):  
J.J. Blaker ◽  
S.N. Nazhat ◽  
V. Maquet ◽  
A.R. Boccaccini

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1655
Author(s):  
Soňa Felšöciová ◽  
Przemysław Łukasz Kowalczewski ◽  
Tomáš Krajčovič ◽  
Štefan Dráb ◽  
Miroslava Kačániová

Contamination of malting barley grain and malt with micromycetes sampled at various periods post-harvest (3rd, 6th, and 9th month of storage) and types of storage (storage silo and floor warehouse) was investigated. Each of these barley grain samples was malted. This article reports on the changes in the fungal microbiome composition and their overall count in barley grain and malt. From the surface-disinfected barley grain samples collected immediately after harvest, there were eight genera isolated, with a predominance of Alternaria. A small increase of isolated microfungi was detected in barley stored in silo for 3 and 6 months (from 142 isolates to 149) and decreased below the number of isolates in barley before storage (133 isolates). Fungal count during storage gradually decreased up to 9 month in barley stored in floor warehouse (from 142 isolates to 84). The initial total count of microscopic fungi in malt before storage was the highest (112 isolates) with 7 genera detected, compared to malts prepared from barley stored for longer time (54 isolates, 7 genera, 9th month of storage). Alternaria was the most abundant and frequent genus. Quantitative representation of the filamentous microscopic fungi was lower compared to yeasts especially in barley and malt prepared from barley stored at third month of storage in both type of storage. Yeasts were identified from all grain samples and malt samples with mass spectrometry. Most attention was given to the widely distributed fungus Penicillium, 79% of strains produced at least one mycotoxin detected under in vitro assays using the TLC method (97% of them produced griseofulvin, 94% CPA, 79% patulin, 14% roquefortin C, and penitrem A was produced by two screening strains under laboratory conditions). It is therefore important to monitor the microflora throughout the production cycle of “barley to beer”.


1970 ◽  
Vol 10 ◽  
pp. 15-20
Author(s):  
Shambhu P. Dhital ◽  
Hira K. Manandhar ◽  
Hak T. Lim

Cryopreservation has been recognized as a practical and efficient tool for long-term storage of vegetatively propagated plants. This study was conducted to investigate the effects of sucrose concentration, hardening temperature and different cryopreservation methods on the survival rate of potato shoot tips after cryopreservation. Excised shoot tips of in vitro plantlets of potato cultivars, Atlantic and Superior were cryopreserved by vitrification, encapsulationvitrification and encapsulation-dehydration. Cryopreservation by vitrification method was used to determine the optimum concentration of sucrose and cold hardening temperature during sub-culturing period to the donor plantlets. Nine-percent sucrose gave 46.7% survival in Atlantic and 40% in Superior. The most optimum hardening temperature for 50% survival in Atlantic and 43.3% in Superior was 10°C. In the case of comparative study of three different cryopreservation methods, the highest survival (52%) as well as regeneration (46%) were observed when the shoot tips were cryopreserved by encapsulation-vitrification method, and the lowest survival (36%) and regeneration (28%) from the vitrification. Plant and tuber morphology of potato regenerated after cryopreservation were similar to those of the non-cryopreserved in vitro plantlets (control). Thus, this study demonstrated that encapsulation-vitrification method was the most effective one among other methods for higher survival as well as regeneration in in vitro shoot tips of potato.Key words: Cryopreservation; Dehydration; Encapsulation; Potato; Regeneration; VitrificationDOI: 10.3126/njst.v10i0.2804Nepal Journal of Science and Technology Volume 10, 2009 December Page: 15-20


2014 ◽  
Vol 41 (No. 2) ◽  
pp. 55-63 ◽  
Author(s):  
Dj. Ružić ◽  
T. Vujović ◽  
R. Cerović

In vitro-grown shoot tips of Gisela 5 (Prunus cerasus × Prunus canescens) cherry rootstock were tested for regrowth after cryopreservation using vitrification technique. Explants were precultured in the dark at 23°C, in a liquid MS medium with a progressively increasing sucrose concentration (0.3 M for 15 h, then 0.7 M for 5 h), and subsequently loaded in a solution containing 2 M glycerol and 0.4 M sucrose for 20 minutes. Shoot tips were dehydrated at 0°C using either the original PVS2 or modified PVS2 solution (PVS A3 – 22.5% sucrose, 37.5% glycerol, 15% ethylene glycol and 15% DMSO) for 30, 40 and 50 minutes. The survival and regrowth of the cryopreserved shoot tips dehydrated with the original PVS2 solution ranged between 36–54% and 8–17%, respectively. However, the dehydration with the PVS A3 solution resulted in considerably higher survival rates (81–92%), as well as higher regrowth rates (39–56%) after cryopreservation. These results prove the feasibility of the PVS A3-based vitrification technique for a long-term storage of this genotype.  


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