Friday, August 5, 2016

PLGA-PEG-PLGA from PolySciTech used for assaying nanoparticle interactions with proteins

PolySciTech division of Akina, Inc. (www.polyscitech.com) provides a wide variety of block copolymers including PLGA-PEG-PLGA. Recently, PLGA-PEG-PLGA from Akina, Inc. was purchased (PolyVivo Catalog#: AK032 and Catalog#: AK017) and used for testing Albumin interaction with these nanoparticles. They confirmed the importance of PEG’s steric hinderance for preventing protein adsorption to nanoparticle. Read more: Geskovski, Nikola, Simona Dimchevska, Rozafa Koliqi, Gjorgji PetruĆĄevski, Marina Chacorovska, Sonja Ugarkovic, and Katerina Goracinova. "A spectroscopic insight into the albumin structure on the nano-bio interface." Your hosts Macedonian Pharmaceutical Association and Faculty of Pharmacy, Ss Cyril and Methodius University in Skopje: 367. https://www.researchgate.net/profile/Irina_Mladenoska/publication/304577752_Effect_of_glucose_concentration_on_glucose_oxidase_activity_in_a_minimal_model_must/links/5773d3e908aeb9427e241721.pdf#page=367


“Synopsis (* quotes compiled from paper sections): It is becoming clear that, when placed into a biological environment, nanoparticles initiate a cascade of interactions with the biomacromolecules resulting in the formation of the ‘protein corona’ (a layer(s) of proteins adsorbed on the nanoparticles surface) (Monopoli et al., 2011). These interactions can alter the secondary structure of the adsorbed proteins promoting instability and/or exposure of new epitopes at the protein surface, thus giving rise to unexpected biological responses (Calzolai et al., 2010). PLGA-PEO-PLGA (Mw 148KDa and Mw 22KDa) was purchased from Akina Inc (USA). Nanoparticle formulations were prepared from PLGAPEO-PLGA (Mw 70,000:8,000:70,000Da) – NP1 and PLGA-PEO-PLGA (Mw 6,000:10,000:6,000Da) – NP2, using the nanoprecipitation method, as described previously All samples were diluted to concentration of 2mg/ml and subsequently 1ml from each formulation was mixed with 1ml of 2mg/mL BSA solution in phosphate buffer (pH 7.4). The NP dispersions with BSA were incubated for 1h at 37°C in a water bath with horizontal shaking at 100 min- 1. After the incubation, the samples were concentrated to 1mL using ultrafiltration tubes with pore size of 1000 kDa, and washed with phosphate buffer pH 7.4. Blank (BSA free) and control sample (without nanoparticles) were also used in the experiment. The amount of adsorbed BSA was indirectly quantified using the Bradford protein assay. The results from the quantitative BSA adsorption studies revealed that 24.6±1.9 and 13.1±0.9% of BSA were adsorbed on the surface of NP1 and NP2, respectively. The results unambiguously point to the effect of the hydrophilic outer nanoparticle layer as a steric barrier for nanoparticle-BSA interactions.”

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