高通量微型生物反应器的研究进展

近年来,哺乳动物细胞培养技术发展迅猛,基于此技术的生物制药行业更是异军突起。在激烈的生物药市场竞争中,缩短研发时间和降低研发成本是制胜的关键。与传统的生物反应器相比,高通量微型生物反应器具有操作简单、运行通量高、实验重复性好等优点,可大大缩短研发周期,降低人力、物力成本,因此成为了生物制药行业最新的研究热点之一。目前,已成功应用于生物药物研发的微型生物反应器有Simcell ^TM、Ambr 15 ^TM、Ambr 250 ^TM等,分别适用于工艺开发中的不同阶段。以上述三种微型生物反应器为例,介绍高通量微型反应器在哺乳动物细胞培养工艺开发中的研究现状及发展前景。     

Designing a blueprint for next-generation stem cell bioprocessing development

The creation of a blueprint for stem cell bioprocess development that it is easily readable and shareable among those involved in the construction of the bioprocess is a necessary step toward full-fledged bioprocess integration. The blueprint provides the culturing tools and methodologies, designed to highlight knowledge gaps within biological sciences and bioengineering. This review highlights a blueprint for stem cell bioprocessing development using a landscape architecture approach that can aid the development of culture technologies and tools that satisfy the demands for stem cell-derived products for use in clinical and industrial applications. This work is intended to provide insights to cell biologists, geneticists, bioengineers, and clinicians seeking knowledge outside of their field of expertise and fosters a leap from a reductionist approach to one, that is, globally integrated in stem cell bioprocessing.     

Process analytics 4.0: A paradigm shift in rapid analytics for biologics development

Analytical testing of product quality attributes and process parameters during the biologics development (Process analytics) has been challenging due to the rapid growth of biomolecules with complex modalities to support unmet therapeutic needs. Thus, the expansion of the process analytics tool box for rapid analytics with the deployment of cutting-edge technologies and cyber-physical systems is a necessity. We introduce the term, Process Analytics 4.0; which entails not only technology aspects such as process analytical technology (PAT), assay automation, and high-throughput analytics, but also cyber-physical systems that enable data management, visualization, augmented reality, and internet of things (IoT) infrastructure for real time analytics in process development environment. This review is exclusively focused on dissecting high-level features of PAT, automation, and data management with some insights into the business aspects of implementing during process analytical testing in biologics process development. Significant technological and business advantages can be gained with the implementation of digitalization, automation, and real time testing. A systematic development and employment of PAT in process development workflows enable real time analytics for better process understanding, agility, and sustainability. Robotics and liquid handling workstations allow rapid assay and sample preparation automation to facilitate high-throughput testing of attributes and molecular properties which are otherwise challenging to monitor with PAT tools due to technological and business constraints. Cyber-physical systems for data management, visualization, and repository must be established as part of Process Analytics 4.0 framework. Furthermore, we review some of the challenges in implementing these technologies based on our expertise in process analytics for biopharmaceutical drug substance development.     

后基因组时代微生物天然产物高效发掘体系设计与展望

微生物天然产物具有丰富的化学结构多样性和诱人的生物活性,持续启迪着创新医药和农药的发现。近年来,随着高通量测序技术的快速发展,巨大的微生物基因组数据揭示了多样生物合成和新颖天然产物的潜能远高于以前的认知。然而,如何高效地激活隐性的生物合成基因簇 (BGCs) 并识别相应的化合物,以及避免已知代谢产物的重复发现等挑战依然严峻。本文描述了面对这些问题时基因组学、生物信息学、机器学习、代谢组学、基因编辑和合成生物学等新技术在发现药用先导化合物过程中提供的机遇;总结并论述了在潜力菌株优选、BGCs的生物信息学预测、沉默 BGCs的高效激活以及目标产物的识别和跟踪方面的新见解;提出了基于潜力菌株选择和多组学挖掘技术从微生物天然产物中高效发现先导结构的系统线路 (SPLSD),并讨论了未来天然产物药用先导发现的机遇和挑战。     

Light it up: highly efficient multigene delivery in mammalian cells

Multigene delivery and expression systems are emerging as key technologies for many applications in contemporary biology. We have developed new methods for multigene delivery and expression in eukaryotic hosts for a variety of applications, including production of protein complexes for structural biology and drug development, provision of multicomponent protein biologics, and cell-based assays. We implemented tandem recombineering to facilitate rapid generation of multicomponent gene expression constructs for efficient transformation of mammalian cells, resulting in homogenous cell populations. Analysis of multiple parameters in living cells may require co-expression of fluorescently tagged sensors simultaneously in a single cell, at defined and ideally controlled ratios. Our method enables such applications by overcoming currently limiting challenges. Here, we review recent multigene delivery and expression strategies and their exploitation in mammalian cells. We discuss applications in drug discovery assays, interaction studies, and biologics production, which may benefit in the future from our novel approach.     

Reproducible culture and differentiation of mouse embryonic stem cells using an automated microwell platform

The use of embryonic stem cells (ESCs) and their progeny in high throughput drug discovery and regenerative medicine will require production at scale of well characterized cells at an appropriate level of purity. The adoption of automated bioprocessing techniques offers the possibility to overcome the lack of consistency and high failure rates seen with current manual protocols. To build the case for increased use of automation this work addresses the key question: “can an automated system match the quality of a highly skilled and experienced person working manually?” To answer this we first describe an integrated automation platform designed for the ‘hands-free’ culture and differentiation of ESCs in microwell formats. Next we outline a framework for the systematic investigation and optimization of key bioprocess variables for the rapid establishment of validatable Standard Operating Procedures (SOPs). Finally the experimental comparison between manual and automated bioprocessing is exemplified by expansion of the murine Oct-4-GiP ESC line over eight sequential passages with their subsequent directed differentiation into neural precursors. Our results show that ESCs can be effectively maintained and differentiated in a highly reproducible manner by the automated system described. Statistical analysis of the results for cell growth over single and multiple passages shows up to a 3-fold improvement in the consistency of cell growth kinetics with automated passaging. The quality of the cells produced was evaluated using a panel of biological markers including cell growth rate and viability, nutrient and metabolite profiles, changes in gene expression and immunocytochemistry. Automated processing of the ESCs had no measurable negative effect on either their pluripotency or their ability to differentiate into the three embryonic germ layers. Equally important is that over a 6-month period of culture without antibiotics in the medium, we have not had any cases of culture contamination. This study thus confirms the benefits of adopting automated bioprocess routes to produce cells for therapy and for use in basic discovery research.     

Antibody informatics for drug discovery

More and more antibody therapeutics are being approved every year, mainly due to their high efficacy and antigen selectivity. However, it is still difficult to identify the antigen, and thereby the function, of an antibody if no other information is available. There are obstacles inherent to the antibody science in every project in antibody drug discovery. Recent experimental technologies allow for the rapid generation of large-scale data on antibody sequences, affinity, potency, structures, and biological functions; this should accelerate drug discovery research. Therefore, a robust bioinformatic infrastructure for these large data sets has become necessary. In this article, we first identify and discuss the typical obstacles faced during the antibody drug discovery process. We then summarize the current status of three sub-fields of antibody informatics as follows: (i) recent progress in technologies for antibody rational design using computational approaches to affinity and stability improvement, as well as ab-initio and homology-based antibody modeling; (ii) resources for antibody sequences, structures, and immune epitopes and open drug discovery resources for development of antibody drugs; and (iii) antibody numbering and IMGT. Here, we review “antibody informatics,” which may integrate the above three fields so that bridging the gaps between industrial needs and academic solutions can be accelerated. This article is part of a Special Issue entitled: Recent advances in molecular engineering of antibody.     

Chemoselective biosensors

New opportunities for biosensors are now appearing in clinical and genetic diagnostics, genomics, environmental protection, food processing and safety, drug discovery and bioprocess monitoring. Concerns about the cost, stability and selectivity of previous sensor technologies are being addressed by developing new recognition systems and their integration into transducers, micro- and nanofabricated devices, array technologies and novel magnetic, acoustic and optical transduction systems.     

Drugs derived from phage display: From candidate identification to clinical practice

Phage display, one of today’s fundamental drug discovery technologies, allows identification of a broad range of biological drugs, including peptides, antibodies and other proteins, with the ability to tailor critical characteristics such as potency, specificity and cross-species binding. Further, unlike in vivo technologies, generating phage display-derived antibodies is not restricted by immunological tolerance. Although more than 20 phage display-derived antibody and peptides are currently in late-stage clinical trials or approved, there is little literature addressing the specific challenges and successes in the clinical development of phage-derived drugs. This review uses case studies, from candidate identification through clinical development, to illustrate the utility of phage display as a drug discovery tool, and offers a perspective for future developments of phage display technology.     

From observational to actionable: rethinking omics in biologics production

As the era of omics continues to expand with increasing ubiquity and success in both academia and industry, omics-based experiments are becoming commonplace in industrial biotechnology, including efforts to develop novel solutions in bioprocess optimization and cell line development. Omic technologies provide particularly valuable ‘observational’ insights for discovery science, especially in academic research and industrial R&D; however, biomanufacturing requires a different paradigm to unlock ‘actionable’ insights from omics. Here, we argue the value of omic experiments in biotechnology can be maximized with deliberate selection of omic approaches and forethought about analysis techniques. We describe important considerations when designing and implementing omic-based experiments and discuss how systems biology analysis strategies can enhance efforts to obtain actionable insights in mammalian-based biologics production.     

CHO细胞株开发技术策略探讨

主要介绍了单克隆抗体药物工业生产中宿主细胞选择、表达载体构建、转染方法、筛选技术、细胞培养工艺技术方法以及最后选定细胞株的标准等,结合单抗药物CHO细胞株开发和培养工艺的经验,对当前我国单抗CHO细胞株开发技术策略进行了探讨。     

Rapid whole monoclonal antibody analysis by mass spectrometry: An Ultra scale‐down study of the effect of harvesting by centrifugation on the post‐translational modification profile

With the trend towards the generation and production of increasing numbers of complex biopharmaceutical (protein based) products, there is an increased need and requirement to characterize both the product and production process in terms of robustness and reproducibility. This is of particular importance for products from mammalian cell culture which have large molecular structures and more often than not complex post‐translational modifications (PTMs) that can impact the efficacy, stability and ultimately the safety of the final product. It is therefore vital to understand how the operating conditions of a bioprocess affect the distribution and make up of these PTMs to ensure a consistent quality and activity in the final product. Here we have characterized a typical bioprocess and determined (a) how the time of harvest from a mammalian cell culture and, (b) through the use of an ultra scale‐down mimic how the nature of the primary recovery stages, affect the distribution and make up of the PTMs observed on a recombinant IgG₄ monoclonal antibody. In particular we describe the use of rapid whole antibody analysis by mass spectrometry to analyze simultaneously the changes that occur to the cleavage of heavy chain C‐terminal lysine residues and the glycosylation pattern, as well as the presence of HL dimers. The time of harvest was found to have a large impact upon the range of glycosylation patterns observed, but not upon C‐terminal lysine cleavage. The culture age had a profound impact on the ratio of different glycan moieties found on antibody molecules. The proportion of short glycans increased (e.g., (G0F)₂ 20–35%), with an associated decrease in the proportion of long glycans with culture age (e.g., (G2F)₂ 7–4%, and G1F/G2F from 15.2% to 7.8%). Ultra scale‐down mimics showed that subsequent processing of these cultures did not change the post‐translational modifications investigated, but did increase the proportion of half antibodies present in the process stream. The combination of ultra scale‐down methodology and whole antibody analysis by mass spectrometry has demonstrated that the effects of processing on the detailed molecular structure of a monoclonal antibody can be rapidly determined early in the development process. In this study we have demonstrated this analysis to be applicable to critical process design decisions (e.g., time of harvest) in terms of achieving a desired molecular structure, but this approach could also be applied as a selection criterion as to the suitability of a platform process for the preparation of a new drug candidate. Also the methodology provides means for bioprocess engineers to predict at the discovery phase how a bioprocess will impact upon the quality of the final product. Biotechnol. Bioeng. 2010;107: 85–95. © 2010 Wiley Periodicals, Inc.     

Micro- and nanotechnology in cell separation

This review describes recent work in cell separation using micro- and nanoscale technologies. These devices offer several advantages over conventional, macroscale separation systems in terms of sample volumes, low cost, portability, and potential for integration with other analytical techniques. More importantly, and in the context of modern medicine, these technologies provide tools for point-of-care diagnostics, drug discovery, and chemical or biological agent detection. This review describes work in five broad categories of cell separation based on (1) size, (2) magnetic attraction, (3) fluorescence, (4) adhesion to surfaces, and (5) new emerging technologies. The examples in each category were selected to illustrate separation principles and technical solutions as well as challenges facing this rapidly emerging field.     

Characterization of 3D pluripotent stem cell aggregates and the impact of their properties on bioprocessing

Pluripotent stem cells (PSCs) have been traditionally expanded on a two-dimensional (2D) surface and require substrates coated with extracellular matrix (ECM) proteins. Recently, PSCs have been successfully expanded in suspension as undifferentiated PSC aggregates, which offer a means for large-scale production. Toward lineage-specific differentiation, PSCs can form aggregate-like structures known as embryoid bodies (EBs). The morphology and size of EBs have been shown to significantly affect the differentiation into specific lineages and three-dimensional (3D) tissue development, thus efforts have been devoted to form size-controlled EBs. The integration of both PSC expansion and differentiation in suspension promotes PSC-derived cell production in bioreactors. However, the cellular organization and differentiation potential of PSC aggregates, as well as the role of the cues provided by the reactors to regulate EB fate, have yet to be fully understood. Despite these challenges, integrated PSC aggregate-based culture provides a platform for a simple, scalable bioprocess for the potential application of PSCs in regenerative medicine, disease modeling, and drug discovery.     

Chemical proteomics and its impact on the drug discovery process

Despite the rapid growth of postgenomic data and fast-paced technology advancement, drug discovery is still a lengthy and difficult process. More effective drug design requires a better understanding of the interaction between drug candidates and their targets/off-targets in various situations. The ability of chemical proteomics to integrate a multiplicity of disciplines enables the direct analysis of protein activities on a proteome-wide scale, which has enormous potential to facilitate drug target elucidation and lead drug verification. Over recent years, chemical proteomics has experienced rapid growth and provided a valuable method for drug target identification and inhibitor discovery. This review introduces basic concepts and technologies of different popular chemical proteomic approaches. It also covers the essential features and recent advances of each approach while underscoring their potentials in drug discovery and development.     

Concerted Antibody and Antigen Discovery by Differential Whole-cell Phage Display Selections and Multi-omic Target Deconvolution

Monoclonal antibody (mAb)-based biologics are well established treatments of cancer. Antibody discovery campaigns are typically directed at a single target of interest, which inherently limits the possibility of uncovering novel antibody specificities or functionalities. Here, we present a target-unbiased approach for antibody discovery that relies on generating mAbs against native target cell surfaces via phage display. This method combines a previously reported method for improved whole-cell phage display selections with next-generation sequencing analysis to efficiently identify mAbs with the desired target cell reactivity. Applying this method to multiple myeloma cells yielded a panel of >50 mAbs with unique sequences and diverse reactivities. To uncover the identities of the cognate antigens recognized by this panel, representative mAbs from each unique reactivity cluster were used in a multi-omic target deconvolution approach. From this, we identified and validated three cell surface antigens: PTPRG, ICAM1, and CADM1. PTPRG and CADM1 remain largely unstudied in the context of multiple myeloma, which could warrant further investigation into their potential as therapeutic targets. These results highlight the utility of optimized whole-cell phage display selection methods and could motivate further interest in target-unbiased antibody discovery workflows.     

Bridging the gap: Facilities and technologies for development of early stage therapeutic mAb candidates

Therapeutic monoclonal antibodies (mAbs) currently dominate the biologics marketplace. Development of a new therapeutic mAb candidate is a complex, multistep process and early stages of development typically begin in an academic research environment. Recently, a number of facilities and initiatives have been launched to aid researchers along this difficult path and facilitate progression of the next mAb blockbuster. Complementing this, there has been a renewed interest from the pharmaceutical industry to reconnect with academia in order to boost dwindling pipelines and encourage innovation. In this review, we examine the steps required to take a therapeutic mAb from discovery through early stage preclinical development and toward becoming a feasible clinical candidate. Discussion of the technologies used for mAb discovery, production in mammalian cells and innovations in single-use bioprocessing is included. We also examine regulatory requirements for product quality and characterization that should be considered at the earliest stages of mAb development. We provide details on the facilities available to help researchers and small-biotech build value into early stage product development, and include examples from within our own facility of how technologies are utilized and an analysis of our client base.Key words: monoclonal antibody, preclinical development, biologics, CHO cells, cell culture     

Applications of cell-based phage display panning to proteomic analysis

In the post-genomic era, proteomics together with genomic tools have led to powerful new strategies in basic and clinical research. These combined “omics” technologies are being integrated into the drug target discovery process. Unlike the genome, the proteome is a highly dynamic entity that requires techniques capable of analyzing on selected populations of proteins in specific biological conditions that reflect the proteins’ functional characteristics. Antibodies have become one of the most important reagents for the analysis of selected populations of proteins, and the application of phage-display antibody libraries to high-throughput antibody generation against large numbers of various antigens provides a tool for proteome-wide protein expression analysis. In this review, we will discuss the utility of phage-display antibodies in proteomics applications, specifically for the discovery of novel disease markers and therapeutic targets.