scholarly journals Measuring the Concentration of Protein Nanoparticles Synthesized by Desolvation Method: Comparison of Bradford Assay, BCA Assay, hydrolysis/UV Spectroscopy and Gravimetric Analysis

2020 ◽  
Author(s):  
Pavel Khramtsov ◽  
Tatyana Kalashnikova ◽  
Maria Bochkova ◽  
Maria Kropaneva ◽  
Valeria Timganova ◽  
...  
Keyword(s):  
Uv Spectroscopy ◽  
Method Comparison ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Nanoparticle Concentration ◽  
Gelatin Nanoparticles ◽  
Protein Nanoparticles ◽  
Bradford Assay ◽  
Analytical Approaches ◽  
Bca Assay

Research paper on sunthesis of protein nanoparticles<div><br><div><b>Abstract</b></div><div>The desolvation technique is one of the most popular methods for preparing protein nanoparticles for medicine, biotechnology, and food applications. We fabricated 11 batches of BSA nanoparticles and 2 batches of gelatin nanoparticles by desolvation method. BSA nanoparticles from 2 batches were cross-linked by heating at +70 °C for 2 h; other nanoparticles were stabilized by glutaraldehyde. We compared several analytical approaches to measuring their concentration: gravimetric analysis, bicinchoninic acid assay, Bradford assay, and alkaline hydrolysis combined with UV spectroscopy. We revealed that the cross-linking degree and method of cross-linking affect both Bradford and BCA assay. Direct measurement of protein concentration in the suspension of purified nanoparticles by dye-binding assays can lead to significant (up to 50-60%) underestimation of nanoparticle concentration. Quantification of non-desolvated protein (indirect method) is affected by the presence of small nanoparticles in supernatants and can be inaccurate when the yield of desolvation is low. The reaction of cross-linker with protein changes UV absorbance of the latter. Therefore pure protein solution is an inappropriate calibrator when applying UV spectroscopy for the determination of nanoparticle concentration. Our recommendation is to determine the concentration of protein nanoparticles by at least two different methods, including gravimetric analysis.<div><br></div></div></div>

scholarly journals Measuring the Concentration of Protein Nanoparticles Synthesized by Desolvation Method: Comparison of Bradford Assay, BCA Assay, hydrolysis/UV Spectroscopy and Gravimetric Analysis

2020 ◽  
Author(s):  
Pavel Khramtsov ◽  
Tatyana Kalashnikova ◽  
Maria Bochkova ◽  
Maria Kropaneva ◽  
Valeria Timganova ◽  
...  
Keyword(s):  
Uv Spectroscopy ◽  
Method Comparison ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Nanoparticle Concentration ◽  
Gelatin Nanoparticles ◽  
Protein Nanoparticles ◽  
Bradford Assay ◽  
Analytical Approaches ◽  
Bca Assay

Research paper on sunthesis of protein nanoparticles<div><br><div><b>Abstract</b></div><div>The desolvation technique is one of the most popular methods for preparing protein nanoparticles for medicine, biotechnology, and food applications. We fabricated 11 batches of BSA nanoparticles and 2 batches of gelatin nanoparticles by desolvation method. BSA nanoparticles from 2 batches were cross-linked by heating at +70 °C for 2 h; other nanoparticles were stabilized by glutaraldehyde. We compared several analytical approaches to measuring their concentration: gravimetric analysis, bicinchoninic acid assay, Bradford assay, and alkaline hydrolysis combined with UV spectroscopy. We revealed that the cross-linking degree and method of cross-linking affect both Bradford and BCA assay. Direct measurement of protein concentration in the suspension of purified nanoparticles by dye-binding assays can lead to significant (up to 50-60%) underestimation of nanoparticle concentration. Quantification of non-desolvated protein (indirect method) is affected by the presence of small nanoparticles in supernatants and can be inaccurate when the yield of desolvation is low. The reaction of cross-linker with protein changes UV absorbance of the latter. Therefore pure protein solution is an inappropriate calibrator when applying UV spectroscopy for the determination of nanoparticle concentration. Our recommendation is to determine the concentration of protein nanoparticles by at least two different methods, including gravimetric analysis.<div><br></div></div></div>

scholarly journals Fabrication and characterization of hexadecyl acrylate cross-linked phase change microspheres

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 69-75
Author(s):  
Haoran Yun ◽  
Xingxiang Zhang
Keyword(s):  
Phase Change ◽  
Smooth Surface ◽  
Bone Conduction ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Orthopedic Implant ◽  
Thermal Gravimetric ◽  
Fabrication And Characterization ◽  
Fast Release

AbstractMicrospheres with phase change properties were fabricated by polymerization of hexadecyl acrylate (HA) and different cross-linking agents. The samples were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA). The results show that, the samples that added cross-linking agents have a smooth surface and the latent heat of them is different. The experiments show that all of the cross-linked copolymer shells can be made into temperature controlled release microspheres. These materials can be potentially applied in the field of thermal energy storage. β-tricalcium phosphate was encapsulated in microspheres to obtain one with a fast release effect. It will effectively promote bone conduction when these microspheres were implanted into a bone defect. This microsphere can be used for orthopedic implant or coating of instrument in the future.

scholarly journals Uptake of Methylene Blue from Aqueous Solution by Pectin–Chitosan Binary Composites

2020 ◽  
Vol 4 (3) ◽  
pp. 95
Author(s):  
Dexu Kong ◽  
Lee D. Wilson
Keyword(s):  
Methylene Blue ◽  
Aqueous Media ◽  
Dye Adsorption ◽  
Adsorption Properties ◽  
Point Of Zero Charge ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Adsorption Sites ◽  
Biopolymer Composites

To address the need to develop improved hybrid biopolymer composites, we report on the preparation of composites that contain chitosan and pectin biopolymers with tunable adsorption properties. Binary biopolymer composites were prepared at variable pectin–chitosan composition in a solvent directed synthesis, dimethyl sulfoxide (DMSO) versus water. The materials were characterized using complementary methods (infrared spectroscopy, thermal gravimetric analysis, pH at the point-of-zero charge, and dye-based adsorption isotherms). Pectin and chitosan composites prepared in DMSO yielded a covalent biopolymer framework (CBF), whereas a polyelectrolyte complex (PEC) was formed in water. The materials characterization provided support that cross-linking occurs between amine groups of chitosan and the –COOH groups of pectin. CBF-based composites had a greater uptake of methylene blue (MB) dye over the PEC-based composites. Composites prepared in DMSO were inferred to have secondary adsorption sites for enhanced MB uptake, as evidenced by a monolayer uptake capacity that exceeded the pectin–chitosan PECs by 1.5-fold. This work provides insight on the role of solvent-dependent cross-linking of pectin and chitosan biopolymers. Sonication-assisted reactions in DMSO favor CBFs, while cross-linking in water yields PECs. Herein, composites with tunable structures and variable physicochemical properties are demonstrated by their unique dye adsorption properties in aqueous media.

Controlled formation of protein nanoparticles by enzymatic cross-linking of α-lactalbumin with horseradish peroxidase

2014 ◽  
Vol 36 ◽  
pp. 53-59 ◽  
Author(s):  
Surender K. Dhayal ◽  
Harry Gruppen ◽  
Renko de Vries ◽  
Peter A. Wierenga
Keyword(s):  
Horseradish Peroxidase ◽  
Cross Linking ◽  
Protein Nanoparticles

Preparation of N-Methylpolyborosilazane -Derived Bulk Si-B-N-C Ceramics by Warm-Pressing and Pressureless Pyrolysis

2012 ◽  
Vol 557-559 ◽  
pp. 1148-1151
Author(s):  
Zhen Quan Liu ◽  
Jing Zhang ◽  
Xian Xing Qiu ◽  
Yu Qing Peng ◽  
Ke Qing Han ◽  
...  
Keyword(s):  
High Temperature ◽  
Ceramic Body ◽  
Thermo Gravimetric Analysis ◽  
Amorphous Structure ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Green Body ◽  
Thermo Gravimetric ◽  
Temperature Resistance ◽  
Bulk Ceramic

Additive-free bulk Si-B-N-C ceramics were prepared by pyrolysis of preceramic precursor (PBS-Me), which mainly involves cross linking, warm-pressing and pyrolysis. The density of crack-free bulk ceramic attains 1.94 g/cm3 when Calcined at 1300 °C. The shaped workpieces exhibit amorphous structure even be pyrolysised at 1400°C in N2, and there are some pores existing in the green body derived from warm-pressing and the resulting Si-B-N-C ceramic body, and these pores allow the gaseous byproducts be expeled from bodies. The pyrolyzed samples were studied by high temperature thermo gravimetric analysis, it shows that the Si-B-N-C body had an excellent high temperature resistance.

scholarly journals Construction of Cellulose/Carboxymethyl Chitosan Hydrogels for Potential Wound Dressing Application

2021 ◽  
Author(s):  
Yi Guo ◽  
Chuanyin Zhao ◽  
Chao Yan ◽  
Li Cui
Keyword(s):  
Wound Dressing ◽  
Thermo Gravimetric Analysis ◽  
Pore Wall ◽  
Carboxymethyl Chitosan ◽  
Cross Linking ◽  
Cellulose Content ◽  
Gravimetric Analysis ◽  
Composite Hydrogels ◽  
Equilibrium Swelling Ratio ◽  
Chitosan Hydrogels

Abstract In this study, novel cellulose/carboxymethyl chitosan (CMCS) composite hydrogels were constructed by blending cellulose and CMCS in LiOH/urea aqueous solutions, and then cross-linking with epichlorohydrin. The structure and morphology of the composite hydrogels were characterized by Fourier transform infrared spectroscopy (FT-IR), wide-angle X-ray diffraction (WXRD), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results revealed that the chemical cross-linking reaction between cellulose and CMCS occurred in the hydrogel, and CMCS contributed to the enhancement of pore size, whereas cellulose as a strong backbone in the hydrogel to support the pore wall. The mechanical strength of the composite hydrogels increased with the cellulose content, while the equilibrium swelling ratio and antibacterial activity increased with the CMCS content. The composite hydrogels had no cytotoxicity towards L929 cells, suggesting good biocompatibility. All these results indicate that cellulose/CMCS composite hydrogels can be effectively used as a material in wound dressing.

scholarly journals Heat-induced changes in cellulose nanocrystal/amino-aldehyde biocomposite systems

2020 ◽  
Vol 142 (6) ◽  
pp. 2371-2383
Author(s):  
Sebestyén Nagy ◽  
Erika Fekete ◽  
János Móczó ◽  
Krisztina Koczka ◽  
Emília Csiszár
Keyword(s):  
Heat Treatment ◽  
Elevated Temperatures ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Factors Affecting ◽  
Biocomposite Films ◽  
Ethylene Urea ◽  
Cellulosic Fibres ◽  
Induced Changes ◽  
Amino Aldehyde

AbstractCellulose nanocrystals (CNCs) were extracted from natural cellulosic fibres such as bleached cotton and flax with a controlled multi-step sulphuric acid hydrolysis. From the aqueous suspensions of CNCs, the biocomposite films were prepared by casting and evaporation, with an amino-aldehyde (AA) compound in a wide concentration range from 0 to 30%. The AA compound (dimethylol dihydroxy ethylene urea) was considered both as a cross-linker of the CNC and as a matrix polymer for the CNC-reinforced composite system. Two series of films were prepared using different polyols such as sorbitol and glycerol as plasticizers to improve tractability. Heat treatment of the films was performed at elevated temperatures ranging from 140 to 200 °C for 10 min. Results clearly proved that besides temperature, the factors affecting the response of CNC-based nanocomposites to heat treatment were the source of cellulose, the type of plasticizer and the amount of cross-linking agent. Films based on flax–CNC and plasticized with glycerol showed a higher increase in yellowness and a more significant decrease in haze than those derived from cotton–CNC and plasticized with sorbitol, respectively. The cross-linking agent (AA) had a moderating effect on the heat-induced changes of properties. Furthermore, thermal gravimetric analysis (TG) of films revealed that thermal stability of the CNC films improved considerably when AA was added and cross-linking occurred. The increase in Tmax was more significant for the flax–CNC films (from about 230 to 290 °C) than for the cotton–CNC ones (from about 250 to 280 °C).

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