Preparation of protein nanoparticle by dynamic aggregation and ionizing-induced crosslinking

ACHILLI, ESTEFANIA; GONZALO CASAJUS; MACARENA SIRI; CONSTANZA FLORES; KADłUBOWSKI, S.; SILVIA ALONSO; MARIANO GRASSELLI

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 486 p. 161 - 171

0927-7757

Globular proteins can be considered as nanotools useful toperform a variety of chemical reactions. These biological macromoleculeshave very complex and detailed topological characteristics responsiblefor their several functions, which can be used for technologicalapplications.Albumin is one of the few commercially available proteins with potentialuse in the preparation of nanomaterials by the bottom-up strategy.Albumin nanoparticles (NPs) can be prepared by several methods, but thepreservation of the structure of the native protein in the finalstructure has not yet received too much attention.Our research group has recently reported the use of ionizing radiation toobtain albumin NPs. The irradiation of an ethanol solution of bovineserum albumin (BSA) allows obtaining protein NPs in the size range of 20to 40 nm. However, a plausible mechanism to explain the process ofpreparation of protein-based NPs has not yet been described. In thiswork, we performed a series of experiments to prepare protein based NPsin two independent steps: (i) dynamic aggregation of BSA by ethanol and(ii) radiation-induced cross-linking by gamma or electron beamirradiation. Dynamic Light Scattering (DLS), Circular Dichroism (CD),Fourier Transform Infrared Spectroscopy (FT-IR) and UV spectroscopymeasurements provided additional information about the conformation ofBSA. No spectroscopy signal changes of aromatic amino acids were detectedby UV and a loss of 20% of the alpha helix secondary structure wasdetermined by CD. Drug-carrier functions were studied by binding andreleasing assays of Merocyanine 540. BSA-NPs showed a drug-carrierbehavior similar to that of BSA. Finally, we evaluated the possibility toprepare protein NPs containing more than one protein using the sameprocedure. Bi-protein NPs were prepared from Lysozyme and BSA. The biproteinNP showed enzymatic activity of Lysozyme, which confirms thefunctionality of the NP prepared by this novel method.