共查询到7条相似文献,搜索用时 5 毫秒
1.
Ma Rosario Rodríguez Niño Juan M. Rodríguez Patino 《Journal of the American Oil Chemists' Society》1998,75(10):1233-1239
The surface activity of bovine serum albumin (BSA) in water and aqueous solutions of ethanol (0.5, 1.0, and 2.0 M) and sucrose
(0.5 and 1.0 M) has been investigated over a range of protein concentrations (5–1.10−5, % w/w). The surface tension data were determined by the Wilhelmy plate method. Surface data at low protein concentrations
indicate a low surface activity, which rises to a plateau as the monolayer is saturated at higher protein concentrations.
The protein concentration and surface tension at the plateau depend on the aqueous phase composition. The effect of aqueous
phase composition on BSA-lipid interactions has been investigated by spreading an insoluble lipid (monostearin or monoolein)
on a film of BSA previously adsorbed on the interface. The existence of protein-lipid interactions depends on the protein/lipid
ratio. The surface activity of mixed BSA-lipid films is determined by the lipid because the surface pressure of the mixed
film is the same as the lipid equilibrium spreading pressure, and the monolayer is not saturated by BSA. However, the surface
activity of mixed BSA-lipid films is determined by BSA as the monolayer is saturated by the protein. 相似文献
2.
M. Rosario Rodríguez Niño Cecilio Carrera Sánchez Marta Cejudo Fernández Juan M. Rodríguez Patino 《Journal of the American Oil Chemists' Society》2001,78(9):873-879
The surface activity of β-casein, caseinate, and a whey protein isolate in aqueous solutions has been investigated over a
range of protein concentrations (1·10−5 to 5% w/w) at pH 5 and 7. The surface pressure data were determined by the Wilhelmy plate method. Surface pressure data at
low protein concentration indicate a low surface activity that rises to a plateau as the monolayer is saturated at higher
protein concentrations. The protein concentration and the surface pressure at the plateau depend on the pH and the type of
protein in the aqueous phase. Protein-monoglyceride interactions were investigated by spreading an insoluble monoglyceride
(monopalmitin, monoolein, or monolaurin) on a film of protein previously adsorbed on the interface at equilibrium. The existence
of protein-monoglyceride interactions depends on the interfacial composition and on the protein/monoglyceride ratio. The surface
activity of mixed protein-monopalmitin and protein-monoolein films is determined by the lipid as the surface pressure of the
mixed film is the same as the monoglyceride equilibrium spreading pressure, and the monolayer is not saturated by the protein.
However, the protein determines the surface activity of mixed protein-monopalmitin and protein-monoolein films as the protein
saturates the monolayer. For protein and monolaurin mixed films, protein determines the surface activity over the range of
protein-monolaurin compositions due to monolaurin dissolution in the bulk aqueous phase. 相似文献
3.
Measurements of the contact angle for water, glycerol, formamide, ethylene glycol, and diiodomethane on polymethyl methacrylate
covered by adsorptive bovine serum albumin (BSA) films were made. Adsorption was performed from solutions in the concentration
range 0–100 g/L. From the obtained contact angles the Lifshitz-van der Waals components and the values of the electron-acceptor
and electrondonor parameters of the acid-based components of the films were calculated for six triplets of liquids. The biggest
changes in the BSA film structure occurred under a monolayer coverage (i.e., at BSA concentrations of <2.5 g/L). On the basis
of the contact angles of glycerol, ethylene glycol, and formamide it was concluded that the density of BSA polar groups was
almost constant. The surface density of the hydrophobic part of the BSA film also seemed constant regardless of the concentration
of the solution from which the BSA adsorptive film was created. This conclusion could be drawn from the almost constant contact
angle of diiodomethane. 相似文献
4.
5.
Study of the adsorption process of bovine serum albumin on passivated surfaces of CoCrMo biomedical alloy 总被引:1,自引:0,他引:1
C. Valero Vidal 《Electrochimica acta》2010,55(28):8445-4801
Adsorption of bovine serum albumin (BSA) on CoCrMo surface was studied by electrochemical techniques in order to determine the mechanism of protein adsorption at different surface conditions (which are reached by considering different passivation times) in phosphate buffered solution (PBS). At open circuit potential (OCP), adsorption kinetic was influenced by surface passivation when passivation time was lower than 1 h, whereas, at higher passivation times, no apparent modification in the kinetic mechanisms of adsorption was observed. On the other hand, at a passive applied potential, the BSA addition decreased the passivation kinetics of the process at all the passivation times. 相似文献
6.
Alternate N-vinyl pyrrolidone/maleic anhydride (NVPMA) copolymers were obtained by radical solution polymerization in dioxane with various MA contents in the monomer feed. The conversion of each monomer was monitored by proton nuclear magnetic resonance spectroscopy (1H NMR), and the kinetics investigation showed that both monomers had identical polymerization rates if both monomers were present in the reaction mixture. The presence of excess NVP in the polymerization medium increased the kinetics of the polymerization and the molar masses of the resulting polymers. This increase was attributed to a cosolvent effect due to NVP, which is a better solvent for the polymer than dioxane. The hydrolysis rate constant of the polymers increased with pH, and NVPMA copolymers were more prone to hydrolysis (by a factor 10) than the methyl vinyl ether ones. Finally, the immobilization of bovin serum albumin (BSA) was investigated. A 25 mM phosphate buffer (pH 5.5) was the best medium to covalently bind 5 BSA molecules onto a 29 kDa NVPMA copolymer and 13 BSA molecules onto a 58 kDa sample, with grafting efficiencies > 90%. Noncovalent interactions with the hydrolyzed form of the polymer and BSA occured at pHs lower than the isoelectric point of BSA, and the resulting complexes were insoluble in water. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3327–3337, 2001 相似文献
7.
Daniel J. Siegwart Jung Kwon OhKrzysztof Matyjaszewski 《Progress in Polymer Science》2012,37(1):18-37
Atom Transfer Radical Polymerization (ATRP) is an effective technique for the design and preparation of multifunctional, nanostructured materials for a variety of applications in biology and medicine. ATRP enables precise control over macromolecular structure, order, and functionality, which are important considerations for emerging biomedical designs. This article reviews recent advances in the preparation of polymer-based nanomaterials using ATRP, including polymer bioconjugates, block copolymer-based drug delivery systems, cross-linked microgels/nanogels, diagnostic and imaging platforms, tissue engineering hydrogels, and degradable polymers. It is envisioned that precise engineering at the molecular level will translate to tailored macroscopic physical properties, thus enabling control of the key elements for realized biomedical applications. 相似文献