scholarly journals Microwell Plate-Based Dynamic Light Scattering as a High-Throughput Characterization Tool in Biopharmaceutical Development

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 172
Author(s):  
Katharina Dauer ◽  
Stefania Pfeiffer-Marek ◽  
Walter Kamm ◽  
Karl G. Wagner

High-throughput light scattering instruments are widely used in screening of biopharmaceutical formulations and can be easily incorporated into processes by utilizing multi-well plate formats. High-throughput plate readers are helpful tools to assess the aggregation tendency and colloidal stability of biological drug candidates based on the diffusion self-interaction parameter (kD). However, plate readers evoke issues about the precision and variability of determined data. In this article, we report about the statistical evaluation of intra- and inter-plate variability (384-well plates) for the kD analysis of protein and peptide solutions. ANOVA revealed no significant differences between the runs. In conclusion, the reliability and precision of kD was dependent on the plate position of the sample replicates and kD value. Positive kD values (57.0 mL/g, coefficients of variation (CV) 8.9%) showed a lower variability compared to negative kD values (−14.8 mL/g, CV 13.4%). The variability of kD was not reduced using more data points (120 vs. 30). A kD analysis exclusively based on center wells showed a lower CV (<2%) compared to edge wells (5–12%) or a combination of edge and center wells (2–5%). We present plate designs for kD analysis within the early formulation development, screening up to 20 formulations consuming less than 50 mg of active pharmaceutical ingredient (API).

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1656
Author(s):  
Nataliya E. Kuz’mina ◽  
Sergey V. Moiseev ◽  
Mikhail D. Khorolskiy ◽  
Anna I. Lutceva

The authors developed a 1H qNMR test procedure for identification and quantification of impurity A present in gabapentin active pharmaceutical ingredient (API) and gabapentin products. The validation studies helped to determine the limit of quantitation and assess linearity, accuracy, repeatability, intermediate precision, specificity, and robustness of the procedure. Spike-and-recovery assays were used to calculate standard deviations, coefficients of variation, confidence intervals, bias, Fisher’s F test, and Student’s t-test for assay results. The obtained statistical values satisfy the acceptance criteria for the validation parameters. The authors compared the results of impurity A quantification in gabapentin APIs and capsules by using the 1H qNMR and HPLC test methods.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Salman Sohrabi ◽  
Danielle E. Mor ◽  
Rachel Kaletsky ◽  
William Keyes ◽  
Coleen T. Murphy

AbstractWe recently linked branched-chain amino acid transferase 1 (BCAT1) dysfunction with the movement disorder Parkinson’s disease (PD), and found that RNAi-mediated knockdown of neuronal bcat-1 in C. elegans causes abnormal spasm-like ‘curling’ behavior with age. Here we report the development of a machine learning-based workflow and its application to the discovery of potentially new therapeutics for PD. In addition to simplifying quantification and maintaining a low data overhead, our simple segment-train-quantify platform enables fully automated scoring of image stills upon training of a convolutional neural network. We have trained a highly reliable neural network for the detection and classification of worm postures in order to carry out high-throughput curling analysis without the need for user intervention or post-inspection. In a proof-of-concept screen of 50 FDA-approved drugs, enasidenib, ethosuximide, metformin, and nitisinone were identified as candidates for potential late-in-life intervention in PD. These findings point to the utility of our high-throughput platform for automated scoring of worm postures and in particular, the discovery of potential candidate treatments for PD.


Marine Drugs ◽  
2018 ◽  
Vol 16 (11) ◽  
pp. 417 ◽  
Author(s):  
Ying Fu ◽  
Cheng Li ◽  
Shuai Dong ◽  
Yong Wu ◽  
Dongting Zhangsun ◽  
...  

Cone snail venoms provide an ideal resource for neuropharmacological tools and drug candidates discovery, which have become a research hotspot in neuroscience and new drug development. More than 1,000,000 natural peptides are produced by cone snails, but less than 0.1% of the estimated conotoxins has been characterized to date. Hence, the discovery of novel conotoxins from the huge conotoxin resources with high-throughput and sensitive methods becomes a crucial key for the conotoxin-based drug development. In this review, we introduce the discovery methodology of new conotoxins from various Conus species. It focuses on obtaining full N- to C-terminal sequences, regardless of disulfide bond connectivity through crude venom purification, conotoxin precusor gene cloning, venom duct transcriptomics, venom proteomics and multi-omic methods. The protocols, advantages, disadvantages, and developments of different approaches during the last decade are summarized and the promising prospects are discussed as well.


2018 ◽  
Vol 23 (6) ◽  
pp. 516-528 ◽  
Author(s):  
Yangjie Wei ◽  
Nicholas R. Larson ◽  
Siva K. Angalakurthi ◽  
C. Russell Middaugh

The goal of protein formulation development is to identify optimal conditions for long-term storage. Certain commercial conditions (e.g., high protein concentration or turbid adjuvanted samples) impart additional challenges to biophysical characterization. Formulation screening studies for such conditions are usually performed using a simplified format in which the target protein is studied at a low concentration in a clear solution. The failure of study conditions to model the actual formulation environment may cause a loss of ability to identify the optimal condition for target proteins in their final commercial formulations. In this study, we utilized a steady-state/lifetime fluorescence-based, high-throughput platform to develop a general workflow for direct formulation optimization under analytically challenging but commercially relevant conditions. A high-concentration monoclonal antibody (mAb) and an Alhydrogel-adjuvanted antigen were investigated. A large discrepancy in screening results was observed for both proteins under these two different conditions (simplified and commercially relevant). This study demonstrates the feasibility of using a steady-state/lifetime fluorescence plate reader for direct optimization of challenging formulation conditions and highlights the importance of performing formulation optimization under commercially relevant conditions.


Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 776 ◽  
Author(s):  
Erzsébet Illés ◽  
Márta Szekeres ◽  
Ildikó Tóth ◽  
Katalin Farkas ◽  
Imre Földesi ◽  
...  

For biomedical applications, superparamagnetic nanoparticles (MNPs) have to be coated with a stealth layer that provides colloidal stability in biological media, long enough persistence and circulation times for reaching the expected medical aims, and anchor sites for further attachment of bioactive agents. One of such stealth molecules designed and synthesized by us, poly(polyethylene glycol methacrylate-co-acrylic acid) referred to as P(PEGMA-AA), was demonstrated to make MNPs reasonably resistant to cell internalization, and be an excellent candidate for magnetic hyperthermia treatments in addition to possessing the necessary colloidal stability under physiological conditions (Illés et al. J. Magn. Magn. Mater. 2018, 451, 710–720). In the present work, we elaborated on the molecular background of the formation of the P(PEGMA-AA)-coated MNPs, and of their remarkable colloidal stability and salt tolerance by using potentiometric acid–base titration, adsorption isotherm determination, infrared spectroscopy (FT-IR ATR), dynamic light scattering, and electrokinetic potential determination methods. The P(PEGMA-AA)@MNPs have excellent blood compatibility as demonstrated in blood sedimentation, smears, and white blood cell viability experiments. In addition, blood serum proteins formed a protein corona, protecting the particles against aggregation (found in dynamic light scattering and electrokinetic potential measurements). Our novel particles also proved to be promising candidates for MRI diagnosis, exhibiting one of the highest values of r2 relaxivity (451 mM−1s−1) found in literature.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Annika Öhrfelt ◽  
Julien Dumurgier ◽  
Henrik Zetterberg ◽  
Agathe Vrillon ◽  
Nicholas J. Ashton ◽  
...  

Abstract Background Neurogranin (Ng) is a neuron-specific and postsynaptic protein that is abundantly expressed in the brain, particularly in the dendritic spine of the hippocampus and cerebral cortex. The enzymatic cleavage of Ng produces fragments that are released into cerebrospinal (CSF), which have been shown to be elevated in Alzheimer’s disease (AD) patients and predict cognitive decline. Thus, quantification of distinctive cleavage products of Ng could elucidate different features of the disease. Methods In this study, we developed novel ultrasensitive single molecule array (Simoa) assays for measurement of full-length neurogranin (FL-Ng) and C-terminal neurogranin (CT-Ng) fragments in CSF. The Ng Simoa assays were evaluated in CSF samples from AD patients (N = 23), mild cognitive impairment due to AD (MCI-AD) (N = 18), and from neurological controls (N = 26). Results The intra-assay repeatability and inter-assay precision of the novel methods had coefficients of variation below 7% and 14%, respectively. CSF FL-Ng and CSF CT-Ng median concentrations were increased in AD patients (6.02 ng/L, P < 0.00001 and 452 ng/L, P = 0.00001, respectively) and in patients with MCI-AD (5.69 ng/L, P < 0.00001 and 566 ng/L, P < 0.00001) compared to neurological controls (0.644 ng/L and 145 ng/L). The median CSF ratio of CT-Ng/FL-Ng were decreased in AD patients (ratio = 101, P = 0.008) and in patients with MCI-AD (ratio = 115, P = 0.016) compared to neurological controls (ratio = 180). CSF of FL-Ng, CT-Ng, and ratio of CT-Ng/FL-Ng could each significantly differentiate AD patients from controls (FL-Ng, AUC = 0.907; CT-Ng, AUC = 0.913; CT-Ng/FL-Ng, AUC = 0.775) and patients with MCI-AD from controls (FL-Ng, AUC = 0.937; CT-Ng, AUC = 0.963; CT-Ng/FL-Ng, AUC = 0.785). Conclusions Assessments of the FL-Ng and CT-Ng levels in CSF with the novel sensitive immunoassays provide a high separation of AD from controls, even in early phase of the disease. The novel Ng assays are robust and highly sensitive and may be valuable tools to study synaptic alteration in AD, as well as to monitor the effect on synaptic integrity of novel drug candidates in clinical trials.


Sign in / Sign up

Export Citation Format

Share Document