Synthesis of Biocompatible Gelatin-functionalised Graphene Nanosheets For Drug Delivery Applications

2014 ◽  
Vol 67 (10) ◽  
pp. 1532 ◽  
Author(s):  
Guangxin Chen ◽  
Congde Qiao ◽  
Yang Wang ◽  
Jinshui Yao
Keyword(s):  
Graphene Nanosheets ◽  
Drug Loading ◽  
Aqueous Dispersion ◽  
Controlled Drug Release ◽  
Reaction Conditions ◽  
Release Process ◽  
Good Ability ◽  
Optimum Reaction ◽  
Good Biocompatibility ◽  
Neutral Conditions

Gelatin-functionalised graphene nanosheets (gelatin-GNS) with good biocompatibility were successfully synthesised using gelatin as a reductant. Factors that affect the reduction of graphene oxide (GO), such as the ratio of gelatin to GO, pH, and temperature, were investigated to establish optimum reaction conditions. We found that GO was efficiently reduced by gelatin at a comparatively low temperature and a stable gelatin-GNS aqueous dispersion was formed. The as-obtained biocompatible gelatin-GNS displayed a high methotrexate (MTX) drug loading capacity and a good ability for controlled drug release. The pH-dependent release behaviour of MTX from MTX@gelatin-GNS showed that the release amount under acid conditions was much higher than that under neutral conditions, indicating a gelatin-mediated sustained release process.

Graphene Oxide Reduced and Dispersed by Polysaccharide

2013 ◽  
Vol 341-342 ◽  
pp. 233-236 ◽  
Author(s):  
Yong Qiang He ◽  
Ru Qiang Li ◽  
Di Wu ◽  
Yong Li Zhang ◽  
Jian Ping Gao ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Low Temperature ◽  
Reduce Graphene Oxide ◽  
Aqueous Dispersion ◽  
Reducing Agent ◽  
Reaction Conditions ◽  
Green Method ◽  
Stabilizing Agent ◽  
Optimum Reaction

An green method to reduce graphene oxide (RGO) was developed by using polysaccharide as both a reducing agent and a stabilizing agent. The RGO was characterized and the factors that affect the reduction of graphene oxide (GO) were explored to obtain optimum reaction conditions. Analysis shows that GO can be reduced at a comparatively low temperature by polysaccharide and forms a stable RGO aqueous dispersion owing to the dispersion of polysaccharide. This approach provides a new green method for GO reduction that has great value for graphene applications.

scholarly journals Tris (2-aminoethyl) Amine Functionalized Nanoporous Silica SBA-15 as a Potential Drug Carrier for Citalopram

2019 ◽  
Vol 4 (4) ◽  
pp. 155-162
Author(s):  
Fatemeh Dalayi ◽  
Leila Hajiaghababaei ◽  
Alireza Badiei ◽  
Elham Boorboor Azimi ◽  
Mohammad Reza Ganjali ◽  
...  
Keyword(s):  
Drug Release ◽  
Release Rate ◽  
Ph Value ◽  
Drug Carrier ◽  
Drug Loading ◽  
Controlled Drug Release ◽  
Nanoporous Silica ◽  
Release Process ◽  
Functionalized Mesoporous Silica ◽  
Amine Functionalized

Introduction: Ordered nanoporous silica such as SBA-15 has a great potential for application in controlled drug release systems. Chemical modification of the silanol groups of SBA-15 allows better control over drug loading and release. Therefore, tris(2-aminoethyl) amine-functionalized mesoporous silica SBA-15 was evaluated as a potential carrier for the delivery of citalopram. Methods: Tris (2-aminoethyl) amine-functionalized SBA-15 was synthesized and characterized by various methods. Citalopram was loaded on the functionalized SBA-15 and drug release into simulated body fluid (SBF) solution and phosphate buffers was investigated. Results: The optimal condition for loading of the citalopram was obtained at pH = 9 after stirring for 5 minutes. The release profile of citalopram was monitored in phosphate buffers with three different pH values of 5, 7, and 8. A faster release rate at lower pH value was observed, suggesting a weaker interaction because of the protonation of the amino group of the functionalized SBA15. The average release rate of citalopram from each gram of functionalized SBA-15 was 12 µg h-1 in the SBF. Conclusion: The results showed that loading amount and release rate of citalopram depended on pH value and the release process showed a very slow release pattern. Therefore, tris (2-aminoethyl) amine-functionalized SBA-15 is a suitable carrier for controlled release of citalopram and has a great potential for disease therapy.

scholarly journals Injectable Hydrogel as a Unique Platform for Antitumor Therapy Targeting Immunosuppressive Tumor Microenvironment

2022 ◽  
Vol 12 ◽  
Author(s):  
Yushuai Liu ◽  
Yuanyuan Geng ◽  
Beilei Yue ◽  
Pui-Chi Lo ◽  
Jing Huang ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Cancer Immunotherapy ◽  
Drug Loading ◽  
Controlled Drug Release ◽  
Injectable Hydrogels ◽  
Convenient Synthesis ◽  
Immunosuppressive Tumor Microenvironment ◽  
Low Toxicity ◽  
Good Biocompatibility ◽  
Minimal Invasion

Cancer immunotherapy can boost the immune response of patients to eliminate tumor cells and suppress tumor metastasis and recurrence. However, immunotherapy resistance and the occurrence of severe immune-related adverse effects are clinical challenges that remain to be addressed. The tumor microenvironment plays a crucial role in the therapeutic efficacy of cancer immunotherapy. Injectable hydrogels have emerged as powerful drug delivery platforms offering good biocompatibility and biodegradability, minimal invasion, convenient synthesis, versatility, high drug-loading capacity, controlled drug release, and low toxicity. In this review, we summarize the application of injectable hydrogels as a unique platform for targeting the immunosuppressive tumor microenvironment.

Study on the Synthesis of Isoamyl Acetate Catalyzed by Strong Acidic Cation Exchange Resin

2011 ◽  
Vol 396-398 ◽  
pp. 2411-2415 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Cation Exchanger ◽  
Cation Exchange Resin ◽  
Isoamyl Acetate ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Reaction Conditions ◽  
Optimum Reaction

Isoamyl acetate was synthesized from isoamylol and glacial acetic acid with strong acidic cation exchanger as catalyst. The effects of reaction conditions such as acid-alcohol ratio, reaction time, catalyst dosage to esterification reaction have been investigated and the optimum reaction conditions can be concluded as: the molar ratio of acetic acid to isoamylol 0.8:1, reaction time 2h, 25 % of catalyst (quality of acetic acid as benchmark). The conversion rate can reach up to 75.46%. The catalytic ability didn’t reduce significantly after reusing 10 times and the results showed that the catalyst exhibited preferably catalytic activity and reusability.

scholarly journals Evaluation of wet air oxidation variables for removal of organophosphorus pesticide malathion using Box-Behnken design

2016 ◽  
Vol 75 (3) ◽  
pp. 619-628 ◽  
Author(s):  
Melike Isgoren ◽  
Erhan Gengec ◽  
Sevil Veli
Keyword(s):  
Removal Efficiency ◽  
Applied Pressure ◽  
Organophosphorus Pesticide ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Reaction Conditions ◽  
Efficient Treatment ◽  
Optimum Reaction

This paper deals with finding optimum reaction conditions for wet air oxidation (WAO) of malathion aqueous solution, by Response Surface Methodology. Reaction conditions, which affect the removal efficiencies most during the non-catalytic WAO system, are: temperature (60–120 °C), applied pressure (20–40 bar), the pH value (3–7), and reaction time (0–120 min). Those were chosen as independent parameters of the model. The interactions between parameters were evaluated by Box-Behnken and the quadratic model fitted very well with the experimental data (29 runs). A higher value of R2 and adjusted R2 (>0.91) demonstrated that the model could explain the results successfully. As a result, optimum removal efficiency (97.8%) was obtained at pH 5, 20 bars of pressure, 116 °C, and 96 min. These results showed that Box–Behnken is a suitable design to optimize operating conditions and removal efficiency for non-catalytic WAO process. The EC20 value of raw wastewater was measured as 35.40% for malathion (20 mg/L). After the treatment, no toxicity was observed at the optimum reaction conditions. The results show that the WAO is an efficient treatment system for malathion degradation and has the ability of converting malathion to the non-toxic forms.

Cleavage of C=N derivatives and Oxidation of Thiols in Water under Neutral Conditions with 1,4-dichloro-1,4-diazoniabicyclo[2,2,2]octane bischloride

2007 ◽  
Vol 2007 (8) ◽  
pp. 486-489 ◽  
Author(s):  
Mahmood Tajbakhsh ◽  
Setareh Habibzadeh
Keyword(s):  
Carbonyl Compounds ◽  
High Yield ◽  
Reaction Conditions ◽  
Neutral Conditions

1,4-Diazabicyclo[2,2,2]octane (DABCO) is easily chlorinated and gives a complex which efficiently converts aliphatic and aromatic oximes, phenylhydrazones and semicarbazones to their corresponding carbonyl compounds in water at 50°C in high yield. This reagent can also be used for conversion of thiols to their compounding disulfide under the same reaction conditions. DABCO is quantitatively recovered which can be rechlorinated and reused several times.

Preparation and Water Absorbency of Superabsorbent Kaolin/PAA-AM Composite

2013 ◽  
Vol 634-638 ◽  
pp. 1968-1976 ◽  
Author(s):  
Shi Han Shen ◽  
Yu Yu Zhang ◽  
Tian Bin Li ◽  
Qing Le Zeng
Keyword(s):  
Composite Material ◽  
Complex Structure ◽  
Water Absorbency ◽  
Solution Polymerization ◽  
Mass Ratio ◽  
Reaction Conditions ◽  
Superabsorbent Composite ◽  
Optimum Reaction ◽  
The Fourier Transform ◽  
Composite Variables

In this paper, a novel superabsorbent composite material based on acrylic acid (AA), acrylic amide (AM) and inorganic kaolin was synthesized via solution polymerization in aqueous medium with N,N’-methylene bisacrylamide (MBA) as crosslinker and potassium persulfate (KPS) as initiator. The effects of water absorbency of the composite variables, such as neutralization, kaolin concentration and MBA concentration, on the water absorbency were systematically optimized. Evidence of compositing was obtained by a comparison of the Fourier transform infrared spectra of the initial reactants with that of the superabsorbent composites, and its complex structure was confirmed with scanning electron microscope. The water absorbing mechanism was also discussed. The results indicated that the superabsorbent composite material was successfully synthesized and the optimum reaction conditions were as follows: the neutralization degree was 80%, the dosage of kaolin, crosslinker and initiator were 4%, 0.11%, and 0.9% respectively and the mass ratio of AA and AM was 3∶2. The optimum absorbency of the superabsorbent composite material in distilled water could reach 815.6g/g.

A Review of Water-Resistant Cellulose-Based Materials in Pharmaceutical and Biomedical Application

2021 ◽  
Vol 28 ◽  
Author(s):  
Bei He ◽  
Xinxin Liu ◽  
Shi Qi ◽  
Run Zheng ◽  
Minmin Chang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Biomedical Application ◽  
Drug Loading ◽  
Cellulose Fibers ◽  
Dip Coating ◽  
Wound Dressings ◽  
Attractive Alternative ◽  
Natural Polymers ◽  
Insoluble Drugs ◽  
Good Biocompatibility

Background: Cellulose, huge reserves of natural polymers, have been widely applied in pharmaceutical and biomedicine fields due to its good biocompatibility, biodegradability, non-toxicity and excellent mechanical properties. At present, water-resistant metal-based and petroleum-based materials applied in medical field exists obvious problems of poor biocompatibility and high cost. Therefore, water-resistant cellulose-based materials with good biocompatibility and low price will become an attractive alternative. This review aims to summarize the preparation of water-resistant cellulose-based materials and their potential application in pharmaceutical and biomedical in recent years. Methods: Common hydrophobic treatments of cellulose fibers or paper were overviewed. The preparation, properties and applications of water-resistant cellulose-based materials in the pharmaceutical and biomedical fields were summarized. Results: Common hydrophobic treatments of cellulose fibers or paper were divided into chemical modification (graft polymerization, crosslinking, solution casting or dip-coating), physico-chemical surface modifications (plasma treatments, surface patterning, electrostatic spraying and electrowetting) and physical processing (electrostatic spinning, SAS process and 3D EHD printing). These hydrophobically processed cellulose fibers or paper could be prepared into various water-resistant cellulose-based materials and applied in pharmaceutical excipients, drug-loaded amphiphilic micelles, drug-loaded composite fibers, hydrophobic biocomposite film/coatings and paper-based detectors. They presented excellent water resistance and biocompatibility, low cytotoxicity and high drug loading ability, and stable drug release rate, etc., which could be used for water-insoluble drugs carriers, wound dressings, and medical testing equipment. Conclusion: Currently, water-resistant cellulose-based materials were mainly applied in water-insoluble drugs delivery carriers, wound dressing and medical diagnosis and presented great application prospects. However, the contradiction between hydrophobicity and mechanical properties of these reported water-resistant cellulose-based materials limited their wider application in biomedicine such as tissue engineering. In the future, attention will be focused on the higher hydrophobicity of water-resistant cellulose-based materials with excellent mechanical properties. In addition, clinical medical research of water-resistant cellulose-based materials should be strengthened.

scholarly journals Indirect spectrophotometric determination of gentamicin and vancomycin antibiotics based on their oxidation by potassium permanganate

2006 ◽  
Vol 4 (4) ◽  
pp. 708-722 ◽  
Author(s):  
Akram El-Didamony ◽  
Alaa Amin ◽  
Ahmed Ghoneim ◽  
Ayman Telebany
Keyword(s):  
Acid Medium ◽  
Potassium Permanganate ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Reaction Conditions ◽  
Subsequent Determination ◽  
Optimum Reaction ◽  
Acid Orange Ii ◽  
Sulphuric Acid Medium

AbstractFour simple, accurate, sensitive and economical procedures (A–D) for the estimation of gentamicin sulphate and vancomycin hydrochloride, both in pure form and in pharmaceutical formulations have been developed. The methods are based on the oxidation of the studied drugs by a known excess of potassium permanganate in sulphuric acid medium and subsequent determination of unreacted oxidant by reacting it with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. The reacted oxidant corresponds to the drug content. Regression analysis of Beer-Lambert plots showed good correlations in the concentration ranges 4–8, 3–8, 4–9 and 5–9 µg ml−1 with gentamicin and 4–8, 1.5–4, 1.5–4 and 3.5–5.5 µg ml−1 with vancomycin for methods A, B, C, and D, respectively. The molar absorptivity, sandell sensitivity, detection and quantification limits were calculated. The stoichiometric ratios for the cited drugs were studied. The optimum reaction conditions and other analytical parameters were evaluated. The influence of the substance commonly employed as excipients with these drugs were studied. The proposed methods were applied to the determination of these drugs in pharmaceutical formulations. The results have demonstrated that the methods are equally accurate and reproducible as the official methods.

scholarly journals Determination of Nickel in End-Fitting of Spoolable Reinforced Plastic Line Pipe

2018 ◽  
Vol 142 ◽  
pp. 01002
Author(s):  
Xiaodong Shao
Keyword(s):  
Ammonium Persulfate ◽  
Reaction Conditions ◽  
Line Pipe ◽  
Acid Gas ◽  
Determination Of Nickel ◽  
Reinforced Plastic ◽  
Relative Standard ◽  
Optimum Reaction ◽  
Fitting In

Spoolable reinforced plastic line pipe will be widely used in the exploitation of acid gas and oil wells. End-fitting is a mechanical device that forms the transition from the spoolable reinforced plastic line pipe to the connector. It was well known that nickel was an important element in the end-fitting. In this paper, a novel spectrophotometric method was described for determination of nickel in the end-fitting of spoolable reinforced plastic line pipe. The method was based on the color reaction between nickel and dimethylglyoxime, which was favored in an alkaline medium, producing a red compound in the presence of ammonium persulfate as an oxidant. Under the optimum reaction conditions the absorption value was proportional to the concentration of nickel in the range of 0.080~0.50% (R2 = 0.9999), and the relative standard deviation was less than 3.0% (n=5). The proposed method was applied successfully to determine nickel in end-fitting of spoolable reinforced plastic line pipe.

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