scholarly journals Drug Leaching Properties of Vancomycin Loaded Mesoporous Hydroxyapatite as Bone Substitutes

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 826 ◽  
Author(s):  
Jayasingh Anita Lett ◽  
Suresh Sagadevan ◽  
Joseph Joyce Prabhakar ◽  
Nor Aliya Hamizi ◽  
Irfan Anjum Badruddin ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Pore Size ◽  
In Vitro Release ◽  
Phosphate Buffer Solution ◽  
Bone Substitutes ◽  
Organic Modifiers ◽  
Buffer Solution ◽  
Modern Health Care ◽  
Impregnation Technique

Infections after bone reconstructive surgery become an authentic therapeutic and economic issue when it comes to a modern health care system. In general; infected bone defects are regarded as contraindications for bone grafting. Since the pathogens develop a biofilm on the inner surface of the bone; local delivery of antibiotics becomes more important. The present work focuses on the synthesis of Mesoporous Hydroxyapatite (MPHAP) loaded with drug Vancomycin (Van) and to investigate its loading and leaching ability in phosphate buffer solution (PBS), to be used for post-operative infections. The effect of pore size on MPHAP was analyzed using different fatty acids as organic modifiers. The impacts of various fatty acids chain length on the morphology and pore size were studied. A simple impregnation technique with optimized conditions ensured a high antibiotic loading (up to 0.476 + 0.0135 mg/mL), with a complete in vitro release obtained within 50 h.

The Study of Albumin Release from Silica/Albumin as a Potential Drug Delivery Carrier

2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Shafiyah Pondi ◽  
Jon Efendi ◽  
Ho Chin Siong ◽  
Lai Sin Yuan ◽  
Sheela Chandren ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Fumed Silica ◽  
In Vitro Release ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Solution Ph ◽  
Drug Delivery Carrier ◽  
High Interaction ◽  
Uv Visible

The drug-delivery field has been an attractive as well as challenging area for research. With the emerging of new formulated drugs and pharmaceutical compounds, development of good drug-delivery system (DDS) is crucially required. This study aims to utilize albumin as the drug template in silica/albumin/drug (S/A/D) system. Prior to designing this system, the interaction between silica and albumin was investigated. It is hypothesized that high interaction between silica and albumin may result in slower drug release over time, which is preferred for a good DDS. Silica and albumin (S/A) materials were prepared by using fumed silica and tetraethyl orthosilicate (TEOS) as the silica precursors. Three different S/A samples were prepared; fumed silica with albumin (FS/A), fumed silica with pre-treated albumin by sodium borohydrate (FS/A-N), and silica sol (TEOS) with albumin (SS/A). In-vitro release of albumin in phosphate buffer solution (pH 7) was carried out to examine the interaction between albumin and silica. The concentration of albumin was detected at 280 nm by UV-visible spectrophotometer. All samples were characterized by diffuse reflectance-UV-visible spectrophotometer (DR-UV), Fourier transform infrared spectrophotometer (FTIR) dan thermogravimetric-differential thermal analysis (TG-DTA). DR-UV results show that SS/A exhibited the lowest absorption intensity at 280 nm, which indicates better interaction between silica and albumin. This result was supported by the presence of Si-O stretching band of silanol at 952 cm-1 from the FTIR spectrum. Release study of albumin demonstrated that the release of albumin from SS/A was slowest compared to those of FS/A and FS/A-N. 

scholarly journals In vitro dissolution and in vivo gamma scintigraphic evaluation of press-coated salbutamol sulfate tablets

2013 ◽  
Vol 63 (4) ◽  
pp. 545-551 ◽  
Author(s):  
Wei Li ◽  
Cai-Hong Shi ◽  
Yi-Ling Sheng ◽  
Ping Cui ◽  
Yu-Qing Zhao ◽  
...  
Keyword(s):  
In Vitro Release ◽  
Phosphate Buffer Solution ◽  
Gamma Scintigraphy ◽  
In Vitro Dissolution ◽  
Salbutamol Sulfate ◽  
Buffer Solution ◽  
Delayed Release ◽  
Vitro Release

Abstract The aim of this study was to investigate the in vitro and in vivo performance of salbutamol sulfate press-coated tablets for delayed release. The in vitro release behavior of press-coated tablets with the outer layer of PEG 6000/ Eudragit S100 blends (2:1) in pH 1.2 (0.1 mol L-1 HCl) and then pH 6.8 buffer solution was examined. Morphological change of the press-coated tablet during in vitro release was recorded with a digital camera. Release of salbutamol sulfate from press-coated tablets was less than 5 % before 3 h and was completed after 8 h in pH 6.8 phosphate buffer solution. In vivo gamma scintigraphy study carried out on healthy men indicated that the designed system released the drug in lower parts of the GI tract after a lag time of 5 hours. The results showed the capability of the system of achieving delayed release of the drug in both in vitro and in vivo gamma scintigraphy studies.

Bacterial chemotaxis to fungal propagules in vitro and in soil

1983 ◽  
Vol 29 (9) ◽  
pp. 1104-1109 ◽  
Author(s):  
D. K. Arora ◽  
A. B. Filonow ◽  
J. L. Lockwood
Keyword(s):  
Sandy Loam ◽  
Phosphate Buffer Solution ◽  
Bacterial Chemotaxis ◽  
Macrophomina Phaseolina ◽  
Buffer Solution ◽  
Erwinia Herbicola ◽  
Cochliobolus Victoriae ◽  
Fungal Propagules ◽  
Loam Soil

Erwinia herbicola, Pseudomonas fluorescens, and P. putida were strongly attracted in vitro to substances exuded by conidia of Cochliobolus victoriae and sclerotia of Macrophomina phaseolina, but not to phosphate buffer solution. Numbers of bacteria attracted to propagules of C. victoriae or M. phaseolina in an unsterilized sandy loam soil were significantly (P = 0.05) greater than background populations occurring in soil saturated with buffer. Chemotactic response was greater to C. victoriae than to M. phaseolina both in vitro and in soil. Results suggest that living fungal propagules may act as attractants for motile bacteria in soil.

Surface Morphological Changes Accompanying Dissolution of Bioactive Glass: Effect of Residual Stress

2008 ◽  
Vol 47-50 ◽  
pp. 1302-1306 ◽  
Author(s):  
John A. Nychka ◽  
Ding Li
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Bioactive Glass ◽  
Morphological Changes ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Mechanochemical Effect ◽  
Dissolution Behaviour ◽  
Glass Surfaces

We report our observations concerning the time evolution of surface morphology occurring during the in vitro immersion of bioactive glass surfaces in contact with phosphate buffer solution. We compare regions under intentionally produced residual stresses via micro-indentation to those where no indentation was performed. The sign of the residual stress is shown to be important for predicting dissolution behaviour; compression retards dissolution, whereas tension enhances dissolution. We analyze our results with a simple model for the work of bond dissociation. We report that a highly constrained residual compressive stress state, such as in an indent, leads to a work deficit in comparison to tension, which accounts for the slower dissolution rate of compressed bioactive glass. Such a mechanochemical effect suggests that the presence of residual stresses from the manufacture of biomedical implants and devices could lead to accelerated or delayed dissolution and that careful control of residual stresses should be sought for predictable performance in dissolvable materials.

scholarly journals Absorption and metabolism of volatile fatty acids by rumen and omasum

2012 ◽  
Vol 36 (1) ◽  
pp. 93-99 ◽  
Author(s):  
João Luiz Pratti Daniel ◽  
João Chrysostomo de Resende Júnior
Keyword(s):  
Fatty Acids ◽  
Mitotic Index ◽  
Volatile Fatty Acids ◽  
Diffusion Chamber ◽  
Serosal Side ◽  
Buffer Solution ◽  
Mucosal Side ◽  
Over Time ◽  
Fractional Absorption

Volatile fatty acids (VFA) absorption and metabolic capacity of rumen and omasum were compared, in vitro. Fragments of rumen wall and omasum laminae were taken from eight adult crossbred bovines. An isolated fragment of the mucosa was fitted in a tissue diffusion chamber. Valeric acid and CrEDTA were added to ruminal fluid and placed on the mucosal side and buffer solution was placed on the serosal side. Fractional absorption rates were measured by exponential VFA:Cr ratio decay over time. Metabolism rate was determined as the difference between VFA absorbed and VFA which appeared on the serosal side over time. Mitotic index was higher in omasum (0.52%) than in rumen epithelium (0.28%). VFA fractional absorption rate was higher in omasum (4.6%/h.cm²) than in rumen (0.4%/h.cm²). Acetate, propionate, butyrate, and valerate showed similar fractional absorption rates in both fragments. Percentage of metabolized acetate and propionate was lower than butyrate and valerate in both stomach compartments. In the rumen, individual VFA metabolism rates were similar (mean of 7.7 , but in the omasum, valerate (90.0 was more metabolized than butyrate (59.6 propionate (69.8 and acetate (51.7 . Correlation between VFA metabolism and mitotic index was positive in the rumen and in the omasum. In conclusion, VFA metabolism and absorption potential per surface of the omasum is higher than that of the rumen. Variations on rumen and omasum absorption capacities occur in the same way, and there are indications that factors capable of stimulating rumen wall proliferation are similarly capable of stimulating omasum walls.

Drug-loaded ultrafine poly(vinyl alcohol) fibre mats prepared by electrospinning

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Chunxue Zhang ◽  
Xiaoyan Yuan ◽  
Lili Wu ◽  
Jing Sheng
Keyword(s):  
Drug Release ◽  
Photoelectron Spectroscopy ◽  
Vinyl Alcohol ◽  
Phosphate Buffer Solution ◽  
Poly Vinyl Alcohol ◽  
High Porosity ◽  
Buffer Solution ◽  
Drug Molecules ◽  
Alcohol Fibre

AbstractSubmicron poly(vinyl alcohol) (PVA) fibre mats embedded with Aspirin and bovine serum albumin (BSA) were prepared by electrospinning of their aqueous solutions. Fibre morphology was investigated by scanning electron microscopy. The composition of the fibre mats was characterized by Fourier transform IR spectroscopy and X-ray photoelectron spectroscopy. The in vitro drug release was investigated by immersing the fibre mats in phosphate buffer solution at 37°C. Results indicated that the morphology of fibre mats was influenced by the amount of drug, and more beaded and irregularly shaped fibres were found with increasing drug amounts. There were drug molecules distributed on the surface of the PVA fibres. Studies of in vitro drug release showed that both Aspirin and BSA were released more quickly from PVA fibre mats than from PVA films because of the large surface area and high porosity of the fibre mats.

scholarly journals Essential oils effect on rumen fermentation and biohydrogenation under in vitro conditions

2014 ◽  
Vol 59 (No. 10) ◽  
pp. 450-459 ◽  
Author(s):  
M. Gunal ◽  
A. Ishlak ◽  
A.A. AbuGhazaleh ◽  
W. Khattab
Keyword(s):  
Fatty Acids ◽  
Essential Oils ◽  
Dose Level ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Rumen Fermentation ◽  
Buffer Solution ◽  
Cinnamon Oil ◽  
Tea Tree

The effects of adding essential oils (EO) at different levels (125, 250, 500 mg/l) on rumen fermentation and biohydrogenation were examined in a rumen batch culture study. Treatments were: control without EO (CON), control with anise oil (ANO), cedar wood oil (CWO), cinnamon oil (CNO), eucalyptus oil (EUO), and tea tree oil (TEO). Essential oils, each dissolved in 1 ml of ethanol, were added to the culture flask containing 40 ml of buffer solution, 2 ml of reduction solution, 10 ml of rumen fluid, 25 mg of soybean oil, and 0.5 g of the diet. After 24 h of incubation in a water batch at 39°C, three samples were collected from each flask and analyzed for ammonia-N, volatile fatty acids (VFA), and fatty acids (FA). Expect for CNO, the proportions of acetate, propionate, and acetate to propionate ratios were not affected (P > 0.05) by EO addition. Addition of CWO, CNO, and TEO reduced total VFA concentrations (P < 0.05) regardless of dose level. The ammonia-N concentration was greater in cultures incubated with EO regardless of dose level. Compared with the CON, the concentrations of C18:0 and trans C18:1 were reduced (P < 0.05) with EO addition regardless of dose level. Compared with the CON, the concentration of linoleic acid was greater (P < 0.05) when EO were added at 500 mg/l. EO tested in this study had no effects on VFA profile but significantly reduced the formation of biohydrogenation products (C18:0 and trans C18:1).

A Comparative Study of the Corrosion Resistance of Stainless Steels Obtained by Powder Metallurgy Techniques for Application in Dental Prosthesis

2010 ◽  
Vol 660-661 ◽  
pp. 617-622 ◽  
Author(s):  
Rogério Albuquerque Marques ◽  
Adonis M. Saliba-Silva ◽  
Sizue Ota Rogero ◽  
Maria de Fátima Montemor ◽  
Isolda Costa
Keyword(s):  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Stainless Steels ◽  
Electrochemical Techniques ◽  
Phosphate Buffer Solution ◽  
Dental Prosthesis ◽  
Powder Injection ◽  
Potential Candidate ◽  
Buffer Solution

- Ferromagnetic stainless steels (SS) produced by powder metallurgy (PM) techniques have been investigated as potential candidates for dental prosthesis applications in replacement of magnetic attachments made of noble and expensive alloys. Two SS were investigated: SS 17-4 PH produced by powder injection (PIM) and SS PM2000 obtained by mechanical alloying. In vitro cytotoxicity analysis of the two SS showed no cytotoxic effects. The magnetic retention force of both tested SS was also evaluated and they were comparable to noble commercially available material that is in use at the moment. The corrosion resistance of both SS was evaluated by electrochemical techniques in sodium phosphate buffer solution (PBS) at 37°C. The AISI 316L SS was also tested under the same conditions for comparison reasons. SS samples tested showed passive behaviour in the electrolyte, but they also presented susceptibility to pitting. The best pitting resistance was associated to the PM2000 whereas the 17-4PH PIM showed the highest pitting susceptibility among the tested steels. The results pointed out that the PM2000 SS might be considered a potential candidate for substitution of high cost magnetic alloys used in dental prosthesis.

scholarly journals Preparation, Characterization, and In Vitro Evaluation of Resveratrol-Loaded Cellulose Aerogel

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1624
Author(s):  
Lili Qin ◽  
Xinyu Zhao ◽  
Yiwei He ◽  
Hongqiang Wang ◽  
Hanjing Wei ◽  
...  
Keyword(s):  
High Speed ◽  
Drug Carrier ◽  
Phosphate Buffer Solution ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Oxidized Cellulose ◽  
Buffer Solution ◽  
Aggregation State ◽  
Cellulose Aerogel

Resveratrol is a natural active ingredient found in plants, which is a polyphenolic compound and has a variety of pharmaceutical uses. Resveratrol-loaded TEMPO-oxidized cellulose aerogel (RLTA) was prepared using a freeze-drying method, employing high speed homogenization followed by rapid freezing with liquid nitrogen. RLTAs were designed at varying drug–cellulose aerogel ratios (1:2, 2:3, 3:2, and 2:1). It could be seen via scanning electron microscopy (SEM) that Res integrated into TEMPO-oxidized cellulose (TC) at different ratios, which changed its aggregation state and turned it into a short rod-like structure. Fourier transform infrared (FTIR) spectra confirmed that the RLTAs had the characteristic peaks of TC and Res. In addition, X-ray diffraction (XRD) demonstrated that the grain size of RLTA was obviously smaller than that of pure Res. RLTAs also had excellent stability in both simulated gastric fluid and phosphate buffer solution. The drug release rate was initially completed within 5 h under a loading rate of 30.7 wt%. The results of an MTT assay showed the low toxicity and good biocompatibility of the RLTAs. TC aerogel could be a promising drug carrier that may be widely used in designing and preparing novel biomedicine.

scholarly journals Performance of Polyester-Based Electrospun Scaffolds under In Vitro Hydrolytic Conditions: From Short-Term to Long-Term Applications

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 786 ◽  
Author(s):  
Oscar Gil-Castell ◽  
José David Badia ◽  
Jordi Bou ◽  
Amparo Ribes-Greus
Keyword(s):  
Molar Mass ◽  
Pure Water ◽  
Phosphate Buffer Solution ◽  
Short Term ◽  
Buffer Solution ◽  
Electrospun Scaffolds ◽  
The Stability ◽  
Short Time

The evaluation of the performance of polyesters under in vitro physiologic conditions is essential to design scaffolds with an adequate lifespan for a given application. In this line, the degradation-durability patterns of poly(lactide-co-glycolide) (PLGA), polydioxanone (PDO), polycaprolactone (PCL) and polyhydroxybutyrate (PHB) scaffolds were monitored and compared giving, as a result, a basis for the specific design of scaffolds from short-term to long-term applications. For this purpose, they were immersed in ultra-pure water and phosphate buffer solution (PBS) at 37 °C. The scaffolds for short-time applications were PLGA and PDO, in which the molar mass diminished down to 20% in a 20–30 days lifespan. While PDO developed crystallinity that prevented the geometry of the fibres, those of PLGA coalesced and collapsed. The scaffolds for long-term applications were PCL and PHB, in which the molar mass followed a progressive decrease, reaching values of 10% for PCL and almost 50% for PHB after 650 days of immersion. This resistant pattern was mainly ascribed to the stability of the crystalline domains of the fibres, in which the diameters remained almost unaffected. From the perspective of an adequate balance between the durability and degradation, this study may serve technologists as a reference point to design polyester-based scaffolds for biomedical applications.

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