Albumin beads

There have been relatively few studies of the properties of the albumin beads or particles. Gupta and Haung (1989) demonstrated that beads made by the emulsification process at temperatures over the range of 105-150°C varied in the release of incorporated doxorubicin, rates decreasing with an increase of the denaturation temperature. This indicated that the beads themselves were becoming hard or more dense. 

Sheu M-T, Sokoloski TD. Entrapment of bioactive compounds within native albumin beads IB evaluation of parameters affecting drug release. / Parenter Sci Technol 1986 40 259—265. 

Rayment, R and Butler, M. F. Investigation of ionically crosslinked chitosan and chitosan-bovine serum albumin beads for novel gastrointestinal functionality. J. Appl. Polym. Sci. 108 (2008) 2876-2885. 

Lee, T.K., T.D. Sokoloski and G.P. Royer, Serum albumin beads an injectable, biodegradable system for the sustained release of drugs, Science, 213 (1981) 233-235. 

Proteins. A chiral stationary phase with immobilized a -acid glycoprotein on silica beads was introduced by Hermansson in 1983 [18, 19]. Several other proteins such as chicken egg albumin (ovalbumin), human serum albumin, and cellohy-drolase were also used later for the preparation of commercial CSPs. Their selectivity is believed to occur as a result of excess of dispersive forces acting on the more retained enantiomer [17]. These separation media often exhibit only modest loading capacity. 

Direct and indirect competition formats, illustrated in Figure 1, are widely used for both qualitative and quantitative immunoassays. Direct competition immunoassays employ wells, tubes, beads, or membranes (supports) on to which antibodies have been coated and in which proteins such as bovine semm albumin, fish gelatin, or powdered milk have blocked nonspecific binding sites. Solutions containing analyte (test solution) and an analyte-enzyme conjugate are added, and the analyte and antibody are allowed to compete for the antibody binding sites. The system is washed, and enzyme substrates that are converted to a chromophore or fluorophore by the enzyme-tracer complex are added. Subsequent color or fluorescence development is inversely proportionate to the analyte concentration in the test solution. For this assay format, the proper orientation of the coated antibody is important, and anti-host IgG or protein A or protein G has been utilized to orient the antibody. Immunoassays developed for commercial purposes generally employ direct competition formats because of their simplicity and short assay times. The price for simplicity and short assay time is more complex development needed for a satisfactory incorporation of the label into the antibody or analyte without loss of sensitivity. 

This observation needs to be compared to the few literature reports on the underlying factors that control the preparation of the albumin particles by the emulsification process. For example, it has been widely reported that parameters such as the variability in stirring rates and temperature had a significant influence on the size of the resulting beads and it has been concluded that the main process variables were controlled by the oil phase of the emulsion. 

For lasalocid assay, polyclonal antibodies were raised in sheep (98). These antisera were applied in an ELISA validated for chicken serum, liver, and muscle. Bridge homology in the ELISA was overcome by absorbing unspecific antisera onto a conjugate between salinomycin and chicken serum albumin, which was immobilized onto Biosilon beads. The assay was highly specific for lasalocid and was capable of detecting it at concentrations less than 0.15 ppb. 

Remove the MTBS from the magnet. Wash the beads with 1 mL TBS and resuspend the beads in the phage solution supplemented with 1% bovine serum albumin (BSA). 

Following the hydrophilic surface modification of the MIP beads, the retention factors of the various employed analytes were decreased, whereas similar or (in the case of (,S )-naproxen) even higher enantioselectivities were observed. Furthermore, the recovery of bovine serum albumin was complete on modified MIPs while it was only 10-40% on unmodified MIPs. Although the column efficiency of modified beads was lower, possibly due to mass transfer limitation by hydrophilic external layers in an aqueous-rich eluent, these preliminary results demonstrated the applicability of RAM-MIPs in direct serum injection assays [95]. 

Column Chromatography. Sepharose beads containing covalently linked gangliosides (0.2 ml packed volume) were placed into a pasteur pipette containing a small amount of glass wool. Columns were washed with HEM containing 50 ug/ml bovine serum albumin (3 ml). Interferon solutions in MEM-albumin (1 ml) were placed on the columns, which were eluted with MEM-albumin at a flow rate of no more than one drop per minute. Fractions of 1 ml were collected and interferon titers determined in each fraction after serial two-fold dilution. Columns onto which mouse fibroblast interferon had been loaded, were eluted with MEM-albumin first, then with 0.07 M N-acetylneuraminyl lactose at pH 2. 

Edwards-Levy, F. and Levy, M.-C. (1999) Serum albumin-alginate coated beads mechanical properties and stability. Biomaterials 20, 2069-2084... 

In order to determine if lectins affect the reactions of complement mediated hemolysis subsequent to binding of antibody to the lymphocyte we have employed a synthetic particulate antigen. This was accomplished by testing the ability of lectin to inhibit the fixation of complement by the complex of anti-human serum albumin (HSA) and HSA-conjugated aminoethyl Biogel beads. The HSA-conjugated aminoethyl Biogel beads may be considered to be cell-like particles coated with a carbohydrate-free protein. 

---