Quality Control Of Biological Products Research Articles

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.

Evaluation of BHK-21 Cell Line for Specific Viruses by Two Different PCR Methods.

The selection of suitable cell cultures for use in the biological industry as well as research and diagnostic studies is critical. One of the factors affecting cell culture that can affect the results of studies is the contamination with viral agents. Therefore, efforts to preserve the health of cell cultures from contamination sound logical, and the use of virus-free cells is vital in research and diagnostic studies as well as in the manufacturing industries. For this purpose, it is crucial to use fast and correct diagnostic methods to detect the presence of critical viral contaminants in cells. Moreover, the use of susceptible diagnostic methods is also doubly important, especially in the case of contaminants that may remain hidden. Therefore, in this study, the BHK-21C5 cell line, one of the most widely used cells in the production and quality control of biological products and virological studies, was examined in terms of contamination with the most important viruses such as BVD and BLV. Detection of possible contaminants by using two-step RT-PCR to detect the 5' UTR portion of the BVD virus. Moreover, Nested PCR was carried out to detect the BLV virus using the gp51 env gene region. Also, an Flk cell line and Hela cell line that were consistently contaminated with the BLV virus were used as positive controls in Nested PCR. Due to the absence of bands in the BHK-21C5 cell column and the bandwidth observed in the positive control column (BVDV) in the range of 283 bp, non-contaminating of the cell clone with the BVD virus was proved. Also, no band was observed in well related to BHK-21C5 cell, and no cell clone contamination with BLV was confirmed, and in wells related to the positive controls (Flk and Hela cells), the bands have seen in the range 444bp. So, the results showed that no obvious or covert viral contamination effect was observed in the cell clone studied. Hence, the use of this cell line seems unobstructed in the quality control and production of biological products and research and diagnostic studies.

Identification of Iranian BHK-21-C5 Cell Line by Two Steps Polymerase Chain Reaction.

Authentication of animal cell lines in cell banks is one of the most important programs regulated during cell culture and storage. This operation provides a thorough and beneficial document which can be advantageous for the functional use of animal cell lines. Therefore, various procedures are used to prevent misidentified cells, cross-contamination to other cell lines, and mislabeling errors leading to incorrect assessment. These contaminants can result in major financial disadvantages. One of the practical methods in this field is a molecular procedure which can demonstrate more accurate results. In the present study, the BHK-21 (C5) was characterized, and it was tried to determine the identity of BHK-21 (C5) as a continuous cell line by Polymerase chain reaction (PCR) molecular procedure in Iran. The cytochrome c oxidase I (CO1) gene was selected as a prevalent DNA fragment for the authentication of the BHK-21 (C5) cell line, along with six cell lines, including Chinese hamster ovary, Lamb kidney, Razi Bovine Kidney, Medical Research Council cell strain 5, Monkey Green Kidney, and Goat Lymphocyte. After amplification, PCR products were analyzed by agarose gel electrophoresis to ensure their accuracy. The results of characterization were indicated, cell viability was estimated to be about 92%, and a uniform cell culture was obtained. The doubling time and µ ratio equivalent were obtained at 20.5 h and 0.03, respectively. Sterility tests revealed that the cell seed was free of bacterial, mycoplasma, and mycobacterial infections. The results of molecular identification revealed that the identification of this cell line was approved and can be used in studies, diagnosis, production, and quality control of biological products.

Flow-Cytometric Method for Viability Analysis of Mycoplasma gallisepticum and Other Cell-Culture-Contaminant Mollicutes.

Mycoplasma is the smallest self-replicating bacteria, figuring as common contaminant of eukaryotic cell cultures. Production inputs and operator's manipulation seem to be the main sources of such contamination. Many analytical approaches have been applied for mycoplasma detection in cell cultures and also in biological products. However, unless they were validated, only indicator cell culture and bacteriological culture are considered as compendial methods for quality control of biological products. Nano-flow cytometry has been pointed out as an alternative technique for addressing prokaryotic and eukaryotic cell viability being a substantial tool for reference material production. In this study, a viability-flow-cytometry assay was standardized for M. gallisepticum and then applied to other cell-culture-contaminant mycoplasmas. For this, M. galliseticum's growth rate was observed and different treatments were evaluated to establish low viability cultures (cell death-induced control). Distinct viability markers and their ideal concentrations (titration) were appraised. Ethanol treatment showed to be the best death-inducing control. CFDA and TOPRO markers revealed to be the best choice for detecting live and dead mycoplasma frequencies, respectively. The standardized methodology was applied to Mycoplasma arginini, M. hyorhinis, M. orale, Spiroplasma citri and Acholeplasma laidlawii. Significant statistical difference was observed in the percentage of viable cells in comparison to ethanol treatment for A. laidlawii in CFDA and in both markers for M. gallisepticum, M. hyorhinis and S. citri. In summary, we standardized a flow cytometry assay for assessing M. gallisepticum - and potentially other species - viability and ultimately applied for reference material production improving the quality control of biological products.

Production and Characterization of a Monoclonal Antibody Neutralizing Poliovirus Type 2

Monoclonal Antibodies (mAbs) are used for biomedical research, diagnosis, treatment, production, and the quality control of biological products. mAbs are also very helpful in poliovirus research studies because it is still one of the major public health problems in developing countries. The main objective of this study was the production of mAbs against Poliovirus Type 2 (PV2) to be prepared and respond to the re-emergence of this virus. After fusion of immunized B cells prepared from mice with myeloma tumor cells and screening of about 250 hybridoma colonies, 22 with the highest antibody titer and without cross-reaction with others types were selected and cloned by limiting dilution. In the end, two colonies capable of secreting mAbs against epitopes of PV2 were used to produce mAbs. The mAbs were characterized by antibody assays, isotyping, and epitopes analysis using western blotting test, the crossreactivity with other types, as well as stability, sterility, and mycoplasma tests. The results indicated that the produced mAbs had high specificity, sensitivity and stability against PV2 without any cross-reactivity and were of IgG1 Kappa chain with similar bands at 26 kDa during electrophoresis associated with viral protein VP3 neutralization. These mAbs were specific in serum neutralization tests for PV2 vaccine strain, and therefore, they are potentially valuable for routine polio research, diagnosis, isolation, production, and control of poliovirus vaccines.

An efficient direct competitive nano-ELISA for residual BSA determination in vaccines.

A simple, fast, and highly sensitive direct competitive enzyme-linked immunosorbent assay (ELISA) based on bovine serum albumin (BSA) antigen labeled amine-terminated silicon dioxide (SiO2-NH-BSA) nanoparticles was developed to determine residual BSA in vaccines. As nano-ELISA using nanomaterials with a very high surface-to-volume ratio has emerged as a promising strategy, SiO2-NH-BSA nanoparticles were prepared in this study by the coupling of BSA to SiO2 nanoparticles modified with amidogen, followed by the quantification of BSA via a direct competitive binding of BSA-antigen-labeled SiO2 nanoparticles to anti-BSA antibody conjugated with horseradish peroxidase. The validation study showed that the linear range of this method was from 1 to 90ng/mL (r = 0.998) and the limit of detection was 0.67ng/mL. The intra-assay and interassay coefficients of variation were less than 10% at three concentrations (10, 40, and 70ng/mL), and the recovery was 92.4%, indicating good specificity. As a proof of principle, this new method was applied in the analysis of residual BSA in five different vaccines. Bland-Altman plots revealed that there was no significant difference in the accuracy and precision between our new method and the most commonly used sandwich ELISA. From the results taken together, the new method developed in this study is more sensitive and facile with lower cost and thus demonstrated potential to be applied in the quality control of biological products. Graphical Abstract Illustration of the procedures of the direct competitive enzyme immunoassay.

673. Establishment of a National Reference Standard for Reverse Transcriptase Activity Assay and Its Applicability in Quality Control of Gene therapy Products

The reverse transcriptase (RT) activity assay is widely used in the quality control of biological products including gene therapy products for it can detect all infectious retroviruses in biological starting materials, cell banks and final products. But the lack of reference standard for RT activity results in significant systemic error and incomparability between laboratories. To standardize RT activity assay, this study established a sensitive real time PCR and developed the first national reference standard, which was prepared from a raw material of recombinant moloney murine leukemia virus reverse transcriptase. Our tests indicated that the candidate reference standard met relevant requirements of the national reference standard. The activity value of candidate RT standard was determined as 26.4 U per ampoule by a collaborative calibration among four laboratories, with the within-laboratory geometric coefficients of variation (GCVs) ranging from 2.7% to 9.6% and the between-laboratory GCV values being 9.8%. The thermal accelerated stability test showed that no loss of activity was observed when the candidate RT standard was stored at 4°C, 25°C and 37 °C compared with -20°C even after 9 months. The applicability study showed that the cell bank and viral bank of an adenovirus gene therapy product were positive and the final products were negative. As a conclusion, the candidate preparation was suitable to serve as a Chinese national standard for RT activity assay and can be used in the quality control of gene therapy products.

Microbiological monitoring of clean rooms in development of vaccines

The aim of the present work was to evaluate an environmental monitoring program for clean rooms, or classified environments, involved in the filling and quality control of biological products produced by Butantan Institute, Sao Paulo, Brazil. This monitoring established the quantification, characterization and seasonality of the microorganisms in air and operators and, moreover, determined the alert and action limits. The total detectable microbial number showed some contrasts in installed air purification systems and in the operational impact on adopted procedures. The typical microbial population consisted of Staphylococcus sp, Micrococcus sp, Bacillus sp and Penicillium sp. The highest microorganism concentration occurred during summer and springtime. The established internal alert and action limits supported the operational procedures. Therefore, the environmental monitoring program is recommended for other laboratories involved in the production of vaccines, hyperimmune sera and biopharmaceuticals.

Specific Quantitation of Genomic DNA in the Femtogram Range by Amplification of Repetitive Sequences

An assay was developed to specifically quantitate concentrations as low as 50 fg/ml genomic DNA based on the amplification of repetitive sequences. Reliable results were obtained by using internal standard molecules which were coextracted, coamplified, and coanalyzed with the nucleic acids of interest. Amplification was performed by the polymerase chain reaction in the presence of fluorescent dye-labeled primers followed by quantitation of fluorescence derived from the reaction products after separation by PAGE. Based on the known amount of added internal standard molecules and the intensities of the fluorescence of the reaction products, the primary results of the assay were obtained as copies per milliliter of sample. These were converted into mass units of DNA by applying an experimentally determined conversion factor. Chicken DNA has been used as an example for genomic DNA, and the sequences amplified were CR1 repetitive elements. This type of assay may be applied in cases where a sensitive and precise quantitation of genomic DNA is required, such as in the quality control of biological products.