One-Step Surface Immobilization of Protein A on Hydrogel Nanofibers by Core-Shell Electrospinning for Capturing Antibodies

Nanofibers (NFs) are potential candidates as filter materials for affinity separation owing to their high liquid permeability based on their high porosity. Multiple and complex processes were conventionally performed to immobilize proteins for modifying NF surfaces. A simple method must be developed to immobilize proteins without impairing their biological activity. Herein, we succeeded in fabricating NFs with a core of cellulose acetate and a shell of hydrophilic polyvinyl alcohol immobilized with staphylococcal recombinant protein A by a one-step process based on core-shell electrospinning. A total of 12.9 mg/cm3 of antibody was captured in the fiber shell through high affinity with protein A immobilized in an aqueous environment of the hydrogel. The maximum adsorption site and dissociation constant evaluated by the Langmuir model were 87.8 µg and 1.37 µmol/L, respectively. The fiber sheet withstood triplicate use. Thus, our NF exhibited high potential as a material for membrane chromatography.

Perspectives, Tendencies, and Guidelines in Affinity-Based Strategies for the Recovery and Purification of PEGylated Proteins

In recent years, the effective purification of PEGylated therapeutic proteins from reaction media has received particular attention. Although several techniques have been used, affinity-based strategies have been scarcely explored despite the fact that, after PEGylation, marked changes in the molecular affinity parameters of the modified molecules are observed. With this in mind, future contributions in the bioseparation of these polymer-protein conjugates are expected to exploit affinity in chromatographic and nonchromatographic techniques which will surely derive in the integration of different operations. However, this will only occur as novel ligands which are simultaneously found. As it will be mentioned, these novel ligands may be screened or designed. In both cases, computer-aided tools will support their identification or development. Additionally, ligand discovery by high-throughput screening (HTS) is believed to become a fast, economic, and informative technology that will aid in the mass production of ligands along with genetic engineering and related technologies. Therefore, besides analyzing the state of the art in affinity separation strategies for PEGylated molecules, this review proposes a basic guideline for the selection of adequate ligands to provide information and prospective on the future of affinity operations in solving this particular bioengineering problem.

Affinity separation and subsequent terminal differentiation of acute myeloid leukemia cells using the human transferrin receptor (CD71) as a capture target

The microfluidic detection of myeloblasts in bloodviathe human transferrin receptor (CD71) can serve as a diagnostic marker for acute myeloid leukemia (AML).