METHODS AND SYSTEM FOR REAL TIME ANALYSIS OF PROTEIN AGGREGATION
Publication Date: 2016-Apr-25
The IP.com Prior Art Database
A method and system for selective real-time analysis of protein aggregation in the presence of variable background such as salt concentration, pH, total concentration of protein, and other types of ambient environmental noise contributions is disclosed. The system includes a sensor, which is a inductor-capacitor-resistor (LCR) resonator. Impedance spectrum of the sensor is measured either via inductive coupling between a pick up coil and the sensor or directly by connecting the sensor to a sensor reader. Electrical response of the sensor is translated into impedance changes of the sensor. Non-limiting examples of response or signal changes of an individual sensor include combined and simultaneous impedance change, resistance change, and capacitance change. The system described herein enhances sensing ability by contacting sample fluid with the sensor between electrodes that constitute a resonant circuit of the sensor.
The present disclosure relates generally to biopharmaceutical manufacturing and more particularly to a method and system for real time analysis of protein aggregation.
Generally, for production of high quality biopharmaceuticals, critical manufacturing parameters are monitored using in-line sensors and at-line analytical systems. Key parameters that are required to be continuously monitored, include temperature, conductivity, pressure, pH, glucose, dissolved oxygen, cell mass, and are similar in single-use and in conventional stainless steel manufacturing systems. Some other parameters such as protein aggregation, cell viability, lactate, glutamine, osmolality, pyruvate, amino acids, product purity, and trace elements are measured at line using laboratory analytical instruments. Unfortunately, not all manufacturing parameters that are critical can be monitored with conventional sensors.
Monitoring protein aggregation is critical for producing high quality and safe biopharmaceuticals. However, conventional methods for the real time in-line detection of protein aggregation present multiple challenges. The key challenges are inability to perform accurate measurements over diverse environmental conditions and in the presence of numerous interferences, and the need to use auxiliary reagents to visualize aggregation.
It would be desirable to have an efficient method and system for real time analysis of protein aggregation in biopharmaceuticals manufacturing.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 depicts principle of measurements of protein aggregation in the presence of variable background. (A) Sensing region where resistance and capacitance of a sensing region change as a function of sample composition. (B) Protein aggregates predictably affect electric field of the sensing region.
Figure 2 depicts operating principle of passive radio-frequency identification (RFID) sensors. Measured impedance spectrum (real part Zre(f) and imaginary part Zim(f) of impedance) and calculated parameters from the measured Ž(f) spectra that includes the frequency position Fp and magnitude Zp of Zre(f), and resonant F1 and antiresonant F2 frequencies, their impedance magnitudes Z1 and Z2 of Zim(f), and zero-reactance frequency FZ of Zim(f).
Figure 3 depicts quantitation of protein aggregation according to an embodiment of the method described herein. (A) Resonant spectra and (B) Calibration curve.
Figure 4 depicts calibration curves for quantitation of protein aggregation according to an embodiment, in samples containing (A) 20 mM of NaCl salt and (B) 200 mM of NaCl salt, and with variable IgG concentration and pH levels.
Figure 5 is a graph depicting effects for various IgG concentrations, NaCl concentrations, pH levels, and protein aggregation levels versus sensor signal change.
Figure 6 is an interaction graph for various IgG concentrations, NaCl concentrations, pH levels, and p...