Real-Time Nanoplasmonic Sensor for IgG Monitoring in Bioproduction
PROCESSES
Authors: Tran, Thuy; Eskilson, Olof; Mayer, Florian; Gustavsson, Robert; Selegard, Robert; Lundstrom, Ingemar; Mandenius, Carl-Fredrik; Martinsson, Erik; Aili, Daniel
Abstract
Real-time monitoring of product titers during process development and production of biotherapeutics facilitate implementation of quality-by-design principles and enable rapid bioprocess decision and optimization of the production process. Conventional analytical methods are generally performed offline/at-line and, therefore, are not capable of generating real-time data. In this study, a novel fiber optical nanoplasmonic sensor technology was explored for rapid IgG titer measurements. The sensor combines localized surface plasmon resonance transduction and robust single use Protein A-modified sensor chips, housed in a flexible flow cell, for specific IgG detection. The sensor requires small sample volumes (1-150 mu L) and shows a reproducibility and sensitivity comparable to Protein G high performance liquid chromatography-ultraviolet (HPLC-UV). The dynamic range of the sensor system can be tuned by varying the sample volume, which enables quantification of IgG samples ranging from 0.0015 to 10 mg/mL, without need for sample dilution. The sensor shows limited interference from the sample matrix and negligible unspecific protein binding. IgG titers can be rapidly determined in samples from filtered unpurified Chinese hamster ovary (CHO) cell cultures and show good correlation with enzyme-linked immunosorbent assay (ELISA).
Study of different routes of immunization using outer membrane vesicles of Neisseria meningitidis B and comparison of two adjuvants
VACCINE
Authors: Brito, Luciana T.; Rinaldi, Fabiana M.; Gaspar, Emanuelle B.; Correa, Victor Araujo; Goncalves, Caroline A.; Portilho, Amanda Izeli; de Lima, Gabriela Trzewikoswki; De Gaspari, Elizabeth
Abstract
Outer membrane vesicles (OMVs) of Neisseria meningitidis contain important antigens to trigger an immune response against meningococci and have been studied as vaccines compounds. The immune response to a vaccine may be affected by its constitution and route of administration. Therefore, Swiss mice were immunized by different routes with OMVs of N. meningitidis B with dimethyl dioctadecyl ammonium bromide in bilayer fragments (DDA-BF) or aluminum hydroxide (AH) as adjuvants. The adjuvants and different routes were compared regarding the immune responses by ELISA, western blot, delayed type hypersensitivity (DTH) and histopathologic analysis. The antigenic preparation generated humoral and cellular immune responses. In quantitative analyzes, in general, AH was superior to DDA-BF. However, analysis such as IgG avidity index, bactericidal activity and immunoblot, revealed no important differences regarding the adjuvant or route of immunization. Regarding the parameters tested, it was not possible to define a superiority between the adjuvants and routes of immunization proposed by this study. (C) 2020 Elsevier Ltd. All rights reserved.