Blood plasma consists of water and its dissolved constituents including especially proteins which mainly serum kinds, that are known as important bearers for many bio active molecules in the blood between serum proteins, bovine serum albumin (BSA) has very engrossed due to its resemblance with human serum albumin, structural stability, solubility in water, low-cost, and facile availability . BSA is composed by the twenty essential amino acids with in a structure which consists of 583 units, These proteins can act as a buffer in aqueous solution. Bovine serum albumin (BSA) is widely used in different biochemical and immunological utilization, owing to its non aggressive stabilizing interaction with most proteins[4,5]. biopolymers are types of materials that are being applied for biomedical applications such as biosensors , enzyme immobilization, drug delivery, and artificial tissues. Therefore, adsorption of BSA on biopolymers can be considered as a facile method to evaluate the applicability of biopolymers in the biomedical application. Protein adsorption process is a complex phenomenon, that is Strongly relative to chemical and the physical properties of the protein and substrate.  the uptake of protein molecules on the surface of substrate is driven by the influence of types of interactions between protein molecules and substrate, involving: Vander Waals forces and Electrostatic interactions . The affecting factors for these interactions not only cover by the properties of protein such as, charge and Charge Density but also by the solution properties like initial protein concentration, solution pH and ion strength. Protein uptake onto various substrates such as, graphene, gold nanoparticles, silica and hydroxyapatite and magnetic-based materials have been reported.
Hydrogels are cross-linked polymer networks, that are swollen in biological fluids or water, they used for biomedical applications such as regenerative medicine, controlled drug delivery and tissue engineering[19,20]. Hydrogels could be prepared by chemical crosslinking of the polymers or by using physical methods ,the physical methods mostly freezing-thawing technique, which is non-aggressive for environment . because of biodegradability, biocompatibility, non-toxicity of biopolymers such as , alginate, chitosan cellulose  and Carrageenan used in the preparation of hydrogels. between them, Chitosan has found potential applications for many cases because of its very sensitive to pH, depending on the pH value can be in the form of a gel or dissolves , owing to the pH-responsive feature, Chitosan -based materials have been widely studied in molecular adsorption and enzyme immobilization [27,28].
Poly (vinyl alcohol) (PVA) is a water-soluble polyhydroxy synthetic polymer. due to its good biodegradability, easy preparation , mechanical properties and high hydrophilicity, It has been extensively used in pharmaceutical and biomedical industry[29,30]. PVA-based hydrogels could prepared by cyclic freezing/thawing method. PVA hydrogels prepared, base this technique have engrossed much attention due to it's the good mechanical stability and lack of any toxic cross-linkers .
Recently, many articles has been reported about the composition of poly(vinyl alcohol) by biopolymers with freezing-thawing technique,such as sodium alginate, kappa-carrageenan and chitosan .The use of hydrogels based on bio polymers due to their unsuitable Physical stability and strength of the gel, is limited. So the addition of very small amount of nanoparticles and nanoclays is a impressive procedure to improve the stability of hydrogels[34,35].many investigations have been reported on preparation of hydrogel nanocomposites based on nanoclays such as, hectorite, sepiolite, montmorillonite and laponite RD .
Magnetic hydrogels nanocomposites were prepared by embedded of magnetite nanoparticles such as, Fe3O4, Fe2O3 and NiFe2O4 in biopolymers[40,41]. because of the selectivity recover desired proteins from biological liquors by the magnetic separation technique, magnetic materials have been widely investigated in the protein separation.. Recently, many investigation have been reported to adsorption of albumin based magnetic adsorbent . for example, magnetic hydrogel beads based on PVA/sodium alginate/laponite RD, magnetic chitosan nanoparticles by a microemulsion system.
In the present study, magnetic hydrogel beads were prepared by the composition of chitosan and poly(vinyl alcohol) by the freezingâ€“thawing method. the magnetic Fe3O4 nanoparticles were synthesize through in situ coprecipitation of iron salts in the presence of laponite RD nanoclay. Then, the PVA-chitosan magnetic hydrogel beads were prepared by the incorporation of magnetic laponite RD. the obtained magnetic hydrogel beads were examined for adsorption of BSA protein. the structure of magnetic hydrogel beads were characterized byTEM, XRD, SEM FT-IR and VSM techniques . Finally, the isotherm and thermodynamics of adsorption process of BSA protein with magnetic hydrogel bead adsorbents were also investigated.
...(download the rest of the essay above)