Adventitious agent detection methods in bio-pharmaceutical applications with a focus on viruses, bacteria, and mycoplasma

Rapid and sensitive Mycoplasma detection in antibody bioprocessing via RPA-CRISPR/Cas12a

Mycoplasma species are prevalent microbial contaminants in the production of biological products, such as monoclonal antibodies, posing significant threats to the safety and efficacy of these products. Current regulatory guidelines as well as pharmacopoeias mandate the demonstration of the absence of Mycoplasma in the cell culture and further downstream processing to ensure product safety. Despite recent advancements in sensitive detection techniques for Mycoplasma in eucaryotic expression systems, these methods remain complex and time-consuming. There is a pressing need for a rapid, simple, and sensitive process analytical technology (PAT) for Mycoplasma detection. Here, we report the first development and application of a recombinase polymerase amplification (RPA)-assisted CRISPR-Cas12a (RPA-CRISPR/Cas12a) system spcifically tailored for Mycoplasma detection in biopharmaceutical production. This system combines the high-sensitivity isothermal nucleic acid amplification capabilities of RPA with the trans-cleavage activity of CRISPR-Cas12a reporter probes, enabling the rapid and accurate detection of Mycoplasma, accommodating various experimental requirements and application scenarios. By designing RPA universal primers and crRNA targeting the highly conserved sequences of Mycoplasma 16S rRNA and optimizing reaction conditions, we achieved dual-specific recognition with unprecedented efficiency in bioprocessing samples. All tested Mycoplasma specimens were detectable with limits between 10 and 0.1 copies/μL, with the whole process taking less than 1 hour. We further evaluated the feasibility of this method in detecting Mycoplasma in the cell culture of antibody products and further downstream processing samples. This method reduces the risk of false-positive signals due to non-specific amplification, enhancing detection sensitivity and specificity while significantly reducing analysis, representing the first PAT-compatible method for rapid Mycoplasma monitoring in antibody manufacturing, thereby providing robust assurance for the quality and safety of biological products.

Analytical control strategy for biologics. Part I: Foundations

Biologic therapeutics encompass different modalities with vastly different molecular profiles. Despite these differences, all products follow a similar approach to Pharmaceutical Development, which includes an integrated control strategy that relies on a clinical target product profile (TPP), a quality target product profile (QTPP), biophysical, biochemical and biological characterization, elucidation of critical quality attributes (CQAs), and development of an analytical control strategy. Technical and regulatory requirements for biologics development are established in numerous regulatory guidance documents issued by ICH, FDA, EMA, and other bodies. While there is substantial published knowledge on specific studies needed for development of a product, there is no specific guidance on establishing a comprehensive analytical control strategy as part of a modern integrated control strategy. This commentary is Part I of a two-part commentary series on analytical control strategy. In this part we present the foundations that are essential for developing an analytical control strategy to enable efficient lifecycle management across different biologic protein-based therapeutic modalities. In Part II, we will present a stage-appropriate roadmap to implementing an analytical control strategy from discovery research through the commercial life of the biologic.

A fluidic device for continuous on-line inductive sensing of proteolytic cleavages

Proteases, an important class of enzymes that cleave proteins and peptides, carry a wealth of potentially useful information. Devices to enable routine and cost effective measurement of their activity could find frequent use in clinical settings for medical diagnostics, as well as some industrial contexts such as detecting on-line biological contamination. In particular, devices that make use of readouts involving magnetic particles may offer distinct advantages for continuous sensing because material they release can be magnetically captured downstream and their readout is insensitive to optical properties of the sample. Bioassays based on giant magnetoresistance sensors that detect the binding or release of magnetic materials have been widely explored for these reasons, but they typically require expensive consumables. Here, we develop a simpler protease sensor based on inductive detection of particle release with pulsed magnetic fields, leveraging a design that incorporates both the pulse coil and gradiometer coils into a printed circuit board. Our fluidic chips are formed from casts of 3D printed molds, such that both the sensor and the consumable components could be relatively easy to mass produce. Using pulses ranging up to 10 s of mT, we show that our device has a limit of detection below 1 μg of iron and that its duty cycle can be varied to control temperature through Joule heating. By chemically functionalizing the glass surface of our fluidic chips with zwitterionic polymer and incorporating a PEG block co-polymer into the PDMS component, we are able to suppress the nonspecific binding of albumin by 7.8 times inside the chips. We demonstrate a layer-by-layer approach for covalently linking magnetic nanoparticles to the chips via cleavable peptide substrates. Finally, we observe the release of the magnetic particles from the chips under conditions of proteolytic cleavage and measure resulting changes in inductive signals, demonstrating a detection sensitivity for chymotrypsin in the hundreds of nM. The methods we establish here have the potential to aid progress toward sensors comprised of disposable fluidic chips measured by inexpensive detection devices that may one day facilitate ubiquitous protease activity monitoring.

Detection of multiple specific adventitious viruses in viral gene therapy products using multiplex PCR coupled with capillary electrophoresis

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Vaccine process technology-A decade of progress

In the past decade, new approaches to the discovery and development of vaccines have transformed the field. Advances during the COVID-19 pandemic allowed the production of billions of vaccine doses per year using novel platforms such as messenger RNA and viral vectors. Improvements in the analytical toolbox, equipment, and bioprocess technology have made it possible to achieve both unprecedented speed in vaccine development and scale of vaccine manufacturing. Macromolecular structure-function characterization technologies, combined with improved modeling and data analysis, enable quantitative evaluation of vaccine formulations at single-particle resolution and guided design of vaccine drug substances and drug products. These advances play a major role in precise assessment of critical quality attributes of vaccines delivered by newer platforms. Innovations in label-free and immunoassay technologies aid in the characterization of antigenic sites and the development of robust in vitro potency assays. These methods, along with molecular techniques such as next-generation sequencing, will accelerate characterization and release of vaccines delivered by all platforms. Process analytical technologies for real-time monitoring and optimization of process steps enable the implementation of quality-by-design principles and faster release of vaccine products. In the next decade, the field of vaccine discovery and development will continue to advance, bringing together new technologies, methods, and platforms to improve human health.

Non-Microbiological Mycobacterial Detection Techniques for Quality Control of Biological Products: A Comprehensive Review

Mycobacteria can be one of the main contaminants of biological products, and their presence can have serious consequences on patients' health. For this reason, the European Pharmacopoeia mandates the specific testing of biological products for mycobacteria, a critical regulatory requirement aimed at ensuring the safety of these products before they are released to the market. The current pharmacopeial reference, i.e., microbial culture method, cannot ensure an exhaustive detection of mycobacteria due to their growth characteristics. Additionally, the method is time consuming and requires a continuous supply of culture media, posing logistical challenges. Thus, to overcome these issues, pharmaceutical industries need to consider alternative non-microbiological techniques to detect these fastidious, slow-growing contaminating agents. This review provides an overview of alternative methods, which could be applied within a quality control environment for biological products and underlines their advantages and limitations. Nucleic acid amplification techniques or direct measurement of mycobacteria stand out as the most suitable alternatives for mycobacterial testing in biological products.

Emerging bacterial factors for understanding pathogenesis of endometriosis

The pathogenesis of endometriosis is a complex process, and recent research has introduced novel hypotheses in this field. This review summarizes recent studies on the pathogenesis of endometriosis. We focused on several classical hypotheses, as well as their interactions with the microenvironment of hormonal dependence and immunosuppression. Furthermore, we highlighted the emergence of bacterial factors associated with endometriosis. Recent advances in next-generation sequencing (NGS) have revealed the presence and detailed distribution of these bacteria as well as the involvement of specific bacteria in pathogenesis. These factors alter the microenvironment in the early stages of endometriosis development, leading to lesion formation. Understanding the mechanisms underlying the early development of endometriosis from a new perspective would be helpful for the development of novel therapeutic agents for endometriosis.

Electrophoretic characterization of LNP/AAV-encapsulated nucleic acids: Strengths and weaknesses

The use of nucleic acids (NAs) has revolutionized medical approaches and ushered in a new era of combating various diseases. Accordingly, there is an increasing demand for accurate identification, localization, quantification, and characterization of NAs encapsulated in nonviral or viral vectors. The vast spectrum of molecular dimensions and intra- and intermolecular interactions presents a formidable obstacle for NA analytical development. Typically, the comprehensive analysis of encapsulated NAs, free NAs, and their spatial distribution poses a challenge that is seldom tackled in its complete complexity. The identification of appropriate physicochemical methodologies for large nonencapsulated or encapsulated NAs is particularly intricate and necessitates an evaluation of the analytical outcomes and their appropriateness in addressing critical quality attributes. In this work, we examine the analytics of non-encapsulated or encapsulated large NAs (>500 nucleotides) utilizing capillary electrophoresis (CE) and liquid chromatography (LC) methodologies such as free zone CE, gel CE, affinity CE, and ion pair high-performance liquid chromatography (HPLC). These methodologies create a complete picture of the NA's critical quality attributes, including quantity, identity, purity, and content ratio.