Infinite n200 pro microplate reader

Quantitative assessment of polymer adsorption to dental surfaces was performed in triplicate by incubation of 1 μM of Texas Red®-labeled polymers in PBS with dental surfaces for 1 hour at 37 °C. Note that the PBS used throughout this work was the following composition: 2.67 mM potassium chloride, 1.47 mM potassium phosphate monobasic, 137.9 mM sodium chloride, and 8.06 mM sodium phosphate dibasic, pH 7.2. The amount of adsorbed polymer was analyzed based on the difference in Texas Red® signal (Ex/Em: 550 nm/617 nm) before and after adsorption, as measured by an Infinite N200 PRO microplate reader (Tecan, Switzerland). Results were confirmed by confocal laser scanning microscopy imaging of HA, sHA, and gsHA surfaces that were incubated with 85 μM polymer solutions for 1 hour at 37 °C. Confocal images were analyzed for surface area coverage by polymers using ImageJ software (v. 1.47). Briefly, the images were transformed to 8 Bit and built-in thresholds (“Moments”) were applied to standardize the images. Five independent areas on each standardized image were selected for analysis. Binding of nanoparticles and p(DMAEMA) to hydroxyapatite (HA) at a range of pH (3.4–10.5) was also quantified to examine how protonation of the p(DMAEMA) tertiary amine residues affect adsorption.

Quantitative assessments of NPC binding to dental surfaces as a function of corona and core sizes and with increase in polymer concentrations were performed in triplicate by incubation of polymers with HA surfaces for 40 minutes at 37°C. The amount of bound polymer was analyzed based on the difference in absorption/emission of Fluorescein fluorescence (Ex/Em: 480 nm /530 nm) before and after incubation as NPC exhibit linear, concentration dependent increase in emission at 530 nm. The binding was measured by an Infinite N200 PRO microplate reader (Tecan, Switzerland) at optimal gain. Binding of p(DMAEMA) to HA versus molecular weight (DM1–4) was similarly.