Bovine Serum Albumin and Lysozyme Adsorption on Calcium Phosphate Particles

Abstract

Two model proteins that are oppositely charged at neutral pH – bovine serum albumin (BSA) and lysozyme, with acidic and alkaline isoelectric points, respectively – are used to investigate the protein adsorption behaviour of hydroxyapatite and beta‐tricalcium phosphate (β‐TCP) particles. Both calcium phosphate based particles are highly relevant for the fabrication of bioactive and resorbable bone implants. The investigations are carried out by combining zeta potential and Vis spectroscopy measurements. The changes of zeta potential and isoelectric point are determined as a function of added protein. Both proteins form a monolayer on β‐TCP, while on hydroxyapatite only semi‐monolayers were measured. For BSA, a side‐on adsorption mode is suggested, whereas end‐on adsorption appears to be most likely for lysozyme. The zeta potential curves as a function of adsorbed protein show that plateaus of the protein amounts adsorbed increase with charge saturation. In addition, the spatial charge distribution of both proteins is modelled to get a further understanding of the initial adsorption orientation of the biomolecules, supporting the findings from the experimental data. The reported findings can be transferred to the adsorption behaviour of a variety of proteins on calcium phosphate surfaces and are helpful for the fabrication of bone‐analogous calcium phosphate/protein nanocomposites.

Phase composition control of calcium phosphate nanoparticles for tunable drug delivery kinetics and treatment of osteomyelitis. I. Preparation and drug release

“…As demonstrated earlier, owing to alternation of charged Ca 2þ and PO 4 3À ions of CAP surface, the latter adsorbs both acidic and alkaline proteins, regardless of its actual f-potential and net charge. 48 Like BSA, fluorescein also exhibits negative charge at pH > 5 due to the presence of a carboxyl group (pK a % 5) and a phenol group (pK a % 6.4), 49 which favors its attraction to Ca 2þ ions on CAP surface.…”

Silber als antibakterielles Agens: Ion, Nanopartikel, Metall

“…[121] Alternative Methoden sind die Verfolgung fluoreszierender Nanopartikel durch konfokale Laserscanningmikroskopie [120,122] und Fluoreszenzmikroskopie, [123] oberflächenverstärkte Raman-Spektroskopie (SERS) [124] und Transmissionselektronenmikroskopie. [96] Die Silber-Nanopartikel werden dabei -wie alle Nanopartikel -in biologischen Medien schnell von einer Hülle ("Korona") aus Proteinen umhüllt, [125][126][127][128][129][130][131] was die Interaktion mit Zellen beeinflusst. [113,132] Metallisches Silber, Silber-Nanopartikel und schwerlçsli-che Silbersalze setzen beim Kontakt mit Wasser Silberionen frei, die das eigentliche biochemisch wirksame Agens sind.…”

Calcium Phosphate Nanocarriers Dual‐Loaded with Bovine Serum Albumin and Ibuprofen: Facile Synthesis, Sequential Drug Loading and Sustained Drug Release

“…[12][13][14][15] Generally, conventional CP materials are of limited use in drug delivery applications due to their low specific surface area, deficiency of organic functional groups on the surface, and low efficiency of drug encapsulation. [19][20][21] BSA is negatively charged in neutral water, and there is an electrostatic interaction between negative BSA molecules and positive Ca 2 + ions. Therefore, it is desirable to develop effective methods for the preparation of nanostructured composite drug delivery systems.…”

“…Therefore, it is desirable to develop effective methods for the preparation of nanostructured composite drug delivery systems. [16,18,20,21] However, studies on dual drug delivery systems obtained by Abstract: A simple and green strategy is reported for the preparation, drug loading, and release properties of a drug delivery system consisting of calcium phosphate (CP) nanocarriers dual-loaded with bovine serum albumin (BSA) and hydrophobic drug ibuprofen (IBU). [16,17] Thus, organic/CP hybrid drug delivery systems may have enhanced performances compared with the singlephase CP.…”

“…Bovine serum albumin (BSA), which is usually used as a model protein drug, can be easily adsorbed on CP materials. [19][20][21] BSA is negatively charged in neutral water, and there is an electrostatic interaction between negative BSA molecules and positive Ca 2 + ions. [22] Thus, BSA molecules can regulate the formation of CP nanostructures.…”