Bovine Serum Albumin Entrapment Efficiency Research Articles

Entrapment of protein in chitosan-tripolyphosphate beads and its release in an in vitro digestive model.

This research sought to evaluate the entrapment and in vitro release behaviour of bovine serum albumin (BSA) in chitosan-tripolyphosphate (TPP) hydrogel beads. Beads were manufactured by extruding gel forming solutions containing varying concentrations of chitosan (1-2.5%w/w) and BSA (0.25-10%w/w) into TPP solutions ranging in concentration from 0.1 to 10%w/w and in ionic strength from 0.16 to 0.67M at pH values of 4, 5 and 9.4. Beads produced at a low TPP concentration of 0.4% w/w had the highest BSA entrapment efficiency (71.6±0.7%) and inhibited BSA release in simulated gastric fluid (SGF) to a greater extent. Increasing chitosan concentration resulted in a higher protein entrapment efficiency, but lowered the overall release. Increasing TPP concentration or the BSA concentration loaded, led to early release in SGF. The results indicate that the utilization of lower concentrations of TPP is a good approach to improve the protein retention ability of chitosan-TPP beads in a simulated gastric environment.

Development of ultrasmall chitosan/succinyl β‐cyclodextrin nanoparticles as a sustained protein‐delivery system

ABSTRACTIn this article, we introduce a new method for preparing ultrasmall chitosan (CS)/succinyl β‐cyclodextrin (SCD) nanoparticles (NPs) intended for loading bovine serum albumin (BSA) as a model protein. The proposed method is based on the complex coacervation technique followed by ionotropic gelation with tripolyphosphate. SCD, an anionic derivative of cyclodextrin, was synthesized and used in CS‐based NPs to enhance the entrapment efficiency of BSA. The results show that with this approach, ultrasmall, compact, and neutralized NPs with a mean particle size near 30 nm were obtained. A high degree of protein entrapment in the NPs led to a significant improvement in the BSA release profile with a low initial burst release (ca. 3% w/v of the initially loaded BSA) and a sustained release over time. This enabled a suitable nanocarrier for long‐term protein delivery (30% release over 120 h). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39648.

Entrapment enhancement of peptide drugs in niosomes

The objective of this study was to enhance the entrapment of various charged peptide drugs [(bacitracin (BCT), insulin and bovine serum albumin (BSA)] in niosomes by modifying the vesicular charge compositions. Cationic, anionic and neutral niosomes were prepared from sorbitan monostearate (Span 60) or polyoxyethylene sorbitan monostearate (Tween 61), cholesterol (CHL), dimethyldioctadecylammonium bromide (DDAB) and/or dicetyl phosphate (DP) in distilled water, by freeze dried empty liposome (FDEL) method. Morphology and vesicular sizes of the vesicles were investigated by optical microscope, TEM, X-ray diffractometry and dynamic light scattering. The entrapment efficiency of the peptides in niosomes was determined by gel electrophoresis and gel documentation. After reconstitution of the empty niosomal powder in phosphate buffer pH 7.0 containing the peptide drugs, they were oligolamellar membrane structure, with the sizes of 40–60 nm, except the neutral niosomes entrapped with insulin and cationic niosomes entrapped with BSA which showed the sizes of 0.1–1.3 µm and 100–150 nm, respectively. The zeta potential values of neutral, cationic and anionic niosomes entrapped with BSA, insulin and BCT were −22.3 ± 1.52, −30.7 ± 2.92 and +22.68± 1.31 mV, respectively. The entrapment efficiency of BSA, BCT and insulin in neutral niosomes (Tween 61/CHL at 1 : 1 molar ratio) was 72.94, 69.89 and 10.26%, in cationic niosomes (Tween 61/CHL/DDAB at 1 : 1 : 0.05 molar ratio) was 84.54, 32.85 and 87.15% and in anionic niosomes (Tween 61/CHL/DP at 1 : 1 : 0.05 molar ratio) was 50.13, 90.88 and 44.31%, respectively. The highest entrapment efficiency of BSA, BCT and insulin at 72.94, 90.88 and 87.15 was observed in neutral, anionic and cationic niosomes, respectively. The results from this study has suggested the appropriate niosomal formulation to entrap the peptides with different charges and polarity for pharmaceutical application.

Controlled delivery of bovine serum albumin from carboxymethyl xanthan microparticles

Bovine serum albumin (BSA)-loaded carboxymethyl xanthan (CMX) microparticles were prepared following gelation of sodium carboxymethyl xanthan (SCMX) gum with different concentrations (1–5%) of aluminium chloride (AlCl3). The microparticles prepared using 1% AlCl3 were subsequently coated with 0.5% aqueous solution of either SCMX gum or sodium alginate. Both uncoated and coated microparticles were characterized for entrapment efficiency, surface morphology, particle size, in vitro release and protein stability. The uncoated microparticles became non-spherical and the mean diameter was found to increase with increasing AlCl3 concentration. Higher concentration of AlCl3 decreased BSA entrapment efficiency of the uncoated microparticles from 86–61%. Furthermore, BSA entrapment in coated microparticles was found lower (78–79%) than uncoated microparticles prepared using 1% AlCl3. Although, the uncoated microparticles released almost half of its content in NaCl-HCl buffer solution (pH 1.2) in 2 h, the alginate and xanthan coated microparticles did not liberate a substantial amount of entrapped protein within the same period and prolonged the release in PBS solution (pH 7.4) up to 10 and 12 h, respectively. The microparticles released the protein via diffusion and swelling of the polymer matrix. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that BSA integrity was well retained in the CMX microparticles.

Controlled release carrier of BSA made by W/O/W emulsion method containing PLGA and hydroxyapatite

This study relates to the Bovine Serum Albumin (BSA) protein-controlled release system with Poly(lactic-glycolic acid) (PLGA) biodegradable polymer. It also has special double emulsification carriers containing alkaline material of hydroxyapatite (HAp), which can carry the hydrophilic drug effectively and sustain a controlled substance release. The controlled release strategy is based on the HAp absorption ability, which will be trapped into the core of PLGA microsphere. Besides, the acidic degradation products of PLGA polymer and basic inorganic component of HAp can be used to control the dissolution of microsphere, then resulting in protein release. We have varied the HAp amount to observe its effect on microsphere characteristics such as the particle size, surface/internal morphology, BSA entrapment efficiency, microsphere degradation, BSA in vitro release behaviour, and cell toxicity etc.

Effect of formulation variables on entrapment efficiency and release characteristics of bovine serum albumin from carboxymethyl xanthan microparticles

AbstractXanthan gum was derivatized to sodium carboxymethyl xanthan (SCMX) gum with a view to prepare bovine serum albumin (BSA)‐loaded carboxymethyl xanthan (CMX) microparticles through interaction with metal ion in a completely aqueous environment. The effect of various formulation variables, such as a pH of SCMX gum solution, concentration of BSA and SCMX gum, and gelation time on BSA entrapment efficiency and release of the protein in different media were studied. While BSA entrapment efficiency was found to decrease with increase in gelation time and initial BSA loading, the same was found to increase with increase in concentration of SCMX gum. Although the release of BSA in acidic medium was almost equal to that in alkaline medium, as compared up to 2 hr, the release in alkaline medium was found to be prolonged to a different extent depending upon the formulation variables. Copyright © 2008 John Wiley & Sons, Ltd.

Heparin/chitosan nanoparticle carriers prepared by polyelectrolyte complexation

In this study, novel nanoparticles were prepared by polyelectrolyte complexation between heparin and chitosan on simple and mild conditions. The size, polydispersity, zeta potential, and morphology of the nanoparticles were characterized. Entrapment studies of the nanoparticles were conducted using bovine serum albumin (BSA) as a model protein. Specifically, the effects of the pH value of chitosan solution, chitosan molecular weight (MW), chitosan concentration, heparin concentration, and BSA concentration on the nanoparticle size, the nanoparticle yield, and BSA entrapment were studied in detail. We found that, the size and the yield of the nanoparticles were affected by the above factors. The nanoparticle yield played a crucial role in BSA entrapment, namely, more nanoparticles could encapsulate more BSA. At length, suitably high pH value of chitosan solution, moderate chitosan MW, increasing both heparin concentration and chitosan concentration at an optimal concentration ratio favored more nanoparticles formed and consequently a higher BSA entrapment efficiency.

Bovine Serum Albumin–Loaded Pectinate Beads as Colonic Peptide Delivery System: Preparation and In Vitro Characterization

Objective of this study was to prepare a drug delivery system for therapeutic peptides that are degraded in the upper part of the gastrointestinal tract due to degradation activity of the enzymes. Delivering peptide to the colon in which enzymatic activity is low is next hope for absorption of these agents. Pectin, a naturally occurring water soluble polysaccharide, as a matrix for peptide delivery was studied. Degradation of pectin by the colonic enzymes makes it suitable for colon-specific delivery of drugs. Bovine serum albumin (BSA) was used as a model peptide. Calcium pectinate beads were prepared by extruding BSA-loaded pectin solution to an agitating calcium chloride solution, and gelled spheres were formed instantaneously by an ionotropic gelation reaction. The effect of several factors such as concentration of pectin, concentration of calcium chloride, and total drug loading on the pattern of drug release in the dissolution medium was studied. Prepared beads showed good resistance in the release medium. The entrapment efficiency of the beads was high (between 63% and 99%). Entrapment efficiency of BSA was reversely dependent to the amount of the drug loaded in the beads. The amount of BSA loaded on the beads affects pattern of drug release. The concentration of the pectin showed the highest impact on the rate of drug release. Presence of the pectiolytic enzymes facilitated the drug release from the beads.

An improvement of double emulsion technique for preparing bovine serum albumin-loaded PLGA microspheres

A modified double emulsion technique was adopted to prepare bovine serum albumin (BSA) loaded poly (D,l-lactic-co-glycolic acid) (PLGA) microspheres. In the formulations, polysorbates (Tween) such as Tween20®, Tween40® or Tween80®, instead of frequently used poly (vinyl alcohol) (PVA), was used as the emulsifier. Microspheres with porous surface, large particle size, low microsphere yield (∼65.4%) and BSA entrapment efficiency (∼25.2%) were obtained when Tween80® aqueous solution alone was used as the outer aqueous phase. However, microspheres with smooth surface, high yield and BSA entrapment efficiency could be produced successfully by introducing sodium chloride or glucose into the outer aqueous phase. Adding 5.0%(w/v) sodium chloride into the continuous phase led to increase in microsphere yield and BSA entrapment efficiency from 65.4% and 25.2% to ∼100% and 76.6%, respectively. Microsphere yield and BSA entrapment efficiency increased from 64.5% and 25.2% to 97.2% and 89.3%, respectively, when 15.0%(w/v) glucose was added into the continuous phase. In constrast to the microspheres prepared in the presence of additive, a more marked burst release was observed for microspheres prepared without additive in the continuous phase, which may be attributed to the porous morphology of the latter.

A method for the preparation of polymeric nanocapsules without stabilizer

In this communication poly(l-lactide) (PLLA) nanocapsules containing bovine serum albumin (BSA) were prepared by means of a modified W/O/W double emulsion technology. A mixture of glycerin and water was used instead of the traditional stabilizer system in the preparation of polymeric nanocapsules. The preliminary results showed that the high viscosity of the mixture and the hydroxyl group of the glycerin were helpful to the formation of the nanocapsules. The prepared nanocapsules had a similar spherical form. By comparison of different polymers of poly(l-lactide) and polycaprolactone-poly(ethylene oxide) block copolymer (PCE), it was found that the entrapment efficiency of the BSA was strongly dependent on the hydrophilicity of the polymer. A lower entrapment efficiency of BSA and nanocapsules with smaller size were obtained when the relative hydrophilic PCE polymer was used as the entrapping material.

Use of an enzyme immunoassay for the evaluation of entrapment efficiency and in vitro stability in intestinal fluids of liposomal bovine serum albumin

The encapsulation efficiency of bovine serum albumin (BSA) within liposomes and its stability in physiological conditions were determined by a specific enzyme immunoassay (EIA) developed for this purpose. BSA was encapsulated within liposomes composed of soyabean phosphatidylcholine (PC), cholesterol (CH), phosphatidylglycerol (PG) (molar ratio 6:3:1) or distearoylphosphatidylcholine (DSPC), CH, PG, (molar ratio 6:3:1). Vesicles were prepared according to either the thin lipid film hydration or freeze-thawing methods. EIA was directly applicable to BSA encapsulated within liposomes without the usual need for sample preparation. The high sensitivity of the method allows high dilution of samples avoiding any interference with liposome formulation as was observed with high performance liquid chromatography (HPLC) method or colorimetric assay. Using this assay it was possible to evaluate that a high entrapment efficiency of BSA was obtained when the vesicles were composed of DSPC/CH/PG and prepared by the freeze-thawing method. Free BSA was stable upon incubation at 37°C for 2 h with acidic or basic buffers and in the presence of 10 mM TC, but was degraded in the presence of a mixture of pancreatin and TC. In the presence of pancreatin alone, BSA entrapped in PC/CH/PG liposomes was less stable than the BSA entrapped in DSPC/CH/PG liposomes. When TC was added to the pancreatin, the stability of BSA (free or encapsulated in PC/CH/PG liposomes) increased, suggesting that after solubilization by TC, phospholipids rearrange forming a new structure in which BSA is protected from degradation. In conclusion, EIA might be a useful tool for the direct evaluation of the encapsulation efficiency and stability of any antigen entrapped in liposomes, without the usual need for sample preparation.