Charge heterogeneity is one of the commonly monitored quality attributes in biotherapeutics. It can impact the stability, efficacy, and safety of products, but it can also affect the pharmacokinetics, binding affinity, and overall biological activity of the molecules. Given the substantial size and complexity of antibodies, subtle variations or specific modifications that result in charge heterogeneity might be concealed when mAbs are analyzed under native conditions.
View Article and Find Full Text PDFMessenger RNA (mRNA) is rapidly growing as a therapeutic modality for vaccination and the treatment of a wide range of diseases. As a result, there is an increased demand for mRNA-based analytical methods capable of assessing purity and stability, which are considered critical quality attributes (CQAs). In recent decades capillary electrophoresis (CE) has emerged alongside liquid chromatography (LC) as an important tool for the assessment of purity and stability of mRNA therapeutics.
View Article and Find Full Text PDFThe 17 Workshop on Recent Issues in Bioanalysis (17 WRIB) took place in Orlando, FL, USA on 19-23 June 2023. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 17 WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week to allow an exhaustive and thorough coverage of all major issues in bioanalysis of biomarkers, immunogenicity, gene therapy, cell therapy and vaccines.
View Article and Find Full Text PDFHeightened interest in messenger RNA (mRNA) therapeutics has accelerated the need for analytical methodologies that facilitate the production of supplies for clinical trials. Forced degradation studies are routinely conducted to provide an understanding of potential weak spots in the molecule that are exploited by stresses encountered during bulk purification, production, shipment, and storage. Consequently, temperature fluctuations and excursions are often experienced during these unit operations and may accelerate mRNA degradation.
View Article and Find Full Text PDFMany methods using liquid chromatography-mass spectrometry (LC-MS) have been established for identifying residual host cell proteins (HCPs) to aid in the process development and quality control of therapeutic proteins. However, the use of MS-based techniques for adeno-associated virus (AAV) is still in its infancy, with few methods reported and minimal information available on potentially problematic HCPs. In this study, we developed a highly sensitive and effective differential digestion method to profile residual HCPs in AAV.
View Article and Find Full Text PDFThe 3' poly(A) tail is an important component of messenger RNA (mRNA). The length of the poly(A) tail has direct impact on the stability and translation efficiency of the mRNA molecule and is therefore considered to be a critical quality attribute (CQA) of mRNA-based therapeutics and vaccines. Various analytical methods have been developed to monitor this CQA.
View Article and Find Full Text PDFThe 16 Workshop on Recent Issues in Bioanalysis (16 WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines.
View Article and Find Full Text PDFAfter more than two decades of research and development, adeno-associated virus (AAV) has become one of the dominant delivery vectors in gene therapy. Despite the focused research, the cell entry pathway for AAV is still not fully understood. Universal AAV receptor (AAVR) has been identified to be involved in cellular entry of different AAV serotypes.
View Article and Find Full Text PDFHost cell proteins (HCPs) are process-related impurities that may copurify with biopharmaceutical drug products. Within this class of impurities there are some that are more problematic. These problematic HCPs can be considered high-risk and can include those that are immunogenic, biologically active, or enzymatically active with the potential to degrade either product molecules or excipients used in formulation.
View Article and Find Full Text PDFSoluble drug target in clinical study samples generated false positive results in anti-drug antibody (ADA) bridging assays due to target-mediated bridging. The combination of two target-blocking reagents and mild basic assay pH resulted in high tolerance to recombinant target protein and reduced levels of positivity in clinical study samples with pharmacokinetic profiles that did not indicate significant ADA response. Testing with low-affinity ADA positive serum from immunized rabbits and known ADA positive samples from nonclinical studies in rats confirmed the assay's ability to detect ADA positive samples and the minimal impact of basic pH and target-blocking reagents on ADA detection.
View Article and Find Full Text PDFThis study demonstrates that benzo[g]chrysene-11,12-dihydrodiol (B[g]C-11,12-dihydrodiol) derived from the fjord-region parent hydrocarbon B[g]C is oxidized by rat AKR1C9 with a k c a t/ K m 100 times greater than that observed with the commonly studied bay-region benzo[ a]pyrene-7,8-dihydrodiol (B[a]P-7,8-dihydrodiol). Conversely, despite its strikingly similar structure to B[ g]C-11,12-dihydrodiol, benzo[ c]phenanthrene-3,4-dihydrodiol (B[ c]Ph-3,4-dihydrodiol) is consumed by AKR1C9 at sluggish rates comparable to those observed with B[ a]P-7,8-dihydrodiol. CD spectroscopy revealed that only the (+)-B[ g]C-11,12-dihydrodiol stereoisomer was oxidized, while AKR1C9 oxidized both stereoisomers of B[a]P-7,8-dihydrodiol and B[ c]Ph-3,4-dihydrodiol.
View Article and Find Full Text PDFA unique multifunctional glycosyl hydrolase was discovered by screening an environmental DNA library prepared from a microbial consortium collected from cow rumen. The protein consists of two adjacent catalytic domains. Sequence analysis predicted that one domain conforms to glycosyl hydrolase family 5 and the other to family 26.
View Article and Find Full Text PDFRecombinant DNA technologies enable the direct isolation and expression of novel genes from biotopes containing complex consortia of uncultured microorganisms. In this study, genomic libraries were constructed from microbial DNA isolated from insect intestinal tracts from the orders Isoptera (termites) and Lepidoptera (moths). Using a targeted functional assay, these environmental DNA libraries were screened for genes that encode proteins with xylanase activity.
View Article and Find Full Text PDFDirected evolution technologies were used to selectively improve the stability of an enzyme without compromising its catalytic activity. In particular, this article describes the tandem use of two evolution strategies to evolve a xylanase, rendering it tolerant to temperatures in excess of 90 degrees C. A library of all possible 19 amino acid substitutions at each residue position was generated and screened for activity after a temperature challenge.
View Article and Find Full Text PDFPolycyclic aromatic hydrocarbons (PAH) are environmental pollutants and suspected human lung carcinogens. In patients with non-small cell lung carcinoma, differential display shows that aldo-keto reductase (AKR1C) transcripts are dramatically overexpressed. However, whether AKR1C isoforms contribute to the carcinogenic process and oxidize potent PAH trans-dihydrodiols (proximate carcinogens) to reactive and redox active o-quinones is unknown; nor is it known whether these reactions occur in human lungs.
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