Chemometrics applications in biotech processes: a review

Biotech unit operations are often characterized by a large number of inputs (operational parameters) and outputs (performance parameters) along with complex correlations amongst them. A typical biotech process starts with the vial of the cell bank, ends with the final product, and has anywhere from 15 to 30 such unit operations in series. The aforementioned parameters can impact process performance and product quality and also interact amongst each other. Chemometrics presents one effective approach to gather process understanding from such complex data sets. The increasing use of chemometrics is fuelled by the gradual acceptance of quality by design and process analytical technology amongst the regulators and the biotech industry, which require enhanced process and product understanding. In this article, we review the topic of chemometrics applications in biotech processes with a special focus on recent major developments. Case studies have been used to highlight some of the significant applications.     

Chemometrics applications in biotech processes: assessing process comparability

A typical biotech process starts with the vial of the cell bank, ends with the final product and has anywhere from 15 to 30 unit operations in series. The total number of process variables (input and output parameters) and other variables (raw materials) can add up to several hundred variables. As the manufacturing process is widely accepted to have significant impact on the quality of the product, the regulatory agencies require an assessment of process comparability across different phases of manufacturing (Phase I vs. Phase II vs. Phase III vs. Commercial) as well as other key activities during product commercialization (process scale-up, technology transfer, and process improvement). However, assessing comparability for a process with such a large number of variables is nontrivial and often companies resort to qualitative comparisons. In this article, we present a quantitative approach for assessing process comparability via use of chemometrics. To our knowledge this is the first time that such an approach has been published for biotech processing. The approach has been applied to an industrial case study involving evaluation of two processes that are being used for commercial manufacturing of a major biosimilar product. It has been demonstrated that the proposed approach is able to successfully identify the unit operations in the two processes that are operating differently. We expect this approach, which can also be applied toward assessing product comparability, to be of great use to both the regulators and the industry which otherwise struggle to assess comparability.     

Guidance for performing multivariate data analysis of bioprocessing data: Pitfalls and recommendations

Biotech unit operations are often characterized by a large number of inputs (operational parameters) and outputs (performance parameters) along with complex correlations among them. A typical biotech process starts with the vial of the cell bank, ends with the final product, and has anywhere from 15 to 30 such unit operations in series. Besides the above‐mentioned operational parameters, raw material attributes can also impact process performance and product quality as well as interact among each other. Multivariate data analysis (MVDA) offers an effective approach to gather process understanding from such complex datasets. Review of literature suggests that the use of MVDA is rapidly increasing, fuelled by the gradual acceptance of quality by design (QbD) and process analytical technology (PAT) among the regulators and the biotech industry. Implementation of QbD and PAT requires enhanced process and product understanding. In this article, we first discuss the most critical issues that a practitioner needs to be aware of while performing MVDA of bioprocessing data. Next, we present a step by step procedure for performing such analysis. Industrial case studies are used to elucidate the various underlying concepts. With the increasing usage of MVDA, we hope that this article would be a useful resource for present and future practitioners of MVDA. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:967–973, 2014     

Fire and stone clearance in Iron Age agriculture: new insights inferred from the analysis of terrestrial macroscopic charcoal in clearance cairns in Hamneda,southern Sweden

Areas with ancient clearance cairns have been studied in Hamneda, Småland Uplands, southern Sweden, by archaeological and palaeoecological methods. Based on numerous radiocarbon dates and stratigraphical analyses, the local introduction of stone clearance is dated to the first century A.D. The clearance cairns reflect a system of semi-mobile cultivation that lasted until c. A.D. 900. Pollen and macrofossil analyses provide information on cereal growing and pastures in these clearance cairn areas, while charcoal analyses reveal details on the agrarian expansion dynamics and the use of fire in vegetation clearance. In the expansion phase, Quercus (oak) woodlands were cleared and transformed to open pastures and arable land, partly by the use of fire. A secondary succession of Betula (birch) and Corylus (hazel) was dealt with by fire clearances to keep pastures open and to prepare new arable plots. In the long run, Betula in particular was favoured by the land-use system. The mobility of the cultivation system is discussed together with the causes behind the introduction of stone clearance. A possible causal relationship with the introduction of hay mowing is also discussed.     

Functional aspects of PARylation in induced and programmed DNA repair processes: Preserving genome integrity and modulating physiological events

To cope with the devastating insults constantly inflicted to their genome by intrinsic and extrinsic DNA damaging sources, cells have evolved a sophisticated network of interconnected DNA caretaking mechanisms that will detect, signal and repair the lesions. Among the underlying molecular mechanisms that regulate these events, PARylation catalyzed by Poly(ADP-ribose) polymerases (PARPs), appears as one of the earliest post-translational modification at the site of the lesion that is known to elicit recruitment and regulation of many DNA damage response proteins.