Author: Alexey Bersenev

Using aptamers for cell isolation

Aptamers are single-stranded RNA or DNA oligonucleotides, which could be screened and synthesized for specific target (including any cell type), using systematic evolution of ligands by exponential enrichment (SELEX) technology. Aptamers are known for more than two decades and have been used successfully for molecular diagnostics, targeted therapy, biomarkers discovery, as biosensensors for cell labeling and other applications. Cell-SELEX technology was used for aptamer-based isolation of cells in cancer and stem cell research (reviewed here). In cell therapy, aptamers could be used for (1) cell tracking (reviewed here) and (2) cell isolation. I’d like to focus on application of aptamers for cell isolation. In research, aptamers have been used for isolation of mesenchymal stromal cells, embryonic stem cells and immune cells. However, to my knowledge, there are no reports on use of aptamers in cell therapy clinical trials (for cell tracking or cell isolation purposes). I was able to find only one research paper, which experimentally assesses therapeutic value of aptamer-isolated cells. Aptamer-based cell isolation is very similar to antibodies. Compared to antibodies, multiple authors are indicating the following advantages of aptamers: small size allows wider bioavailability lack of immunogenicity easy chemical synthesis and scale-out manufacturing easy to modify high stability possibility of decoupling from the cells. Aptamers and antibodies have comparable specificity and result in similar cell yield after isolation. Potential disadvantages of aptamers in cell therapy are...

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New cell separation technologies in research

The current research market of cell separation is hugely dominated by three companies – Stem Cell Technologies (Canada), Miltenyi Biotec (Germany) and Thermo Fisher (Dynal brand). Everyone, who involved in cell research, knows these brands and use their products. After 2 decades, magnetic cell separation methods, developed by these companies, became “conventional” or standard in research. Today, I’d like to look beyond “conventional” brands and briefly overview new comers to the world of cell separation. New companies with new technologies are diversifying the market and offering some advantages. I’d like crowdsource here – please feel free to add new companies if I missed them. PluriSelectGerman company, which offers non-magnetic cell isolation kits and reagents for researchers. Competitive advantage of their technology is simultaneous and/ or sequential isolation of multiple cell populations.Learn more from video tutorials.Also, check this protocol: Cascade System for Simultaneous Separation of Multiple Cell Types Quad TechnologiesUS-based startup, which entered cell separation market last year. Company offers hydrogel-based technology for magnetic tag-free cell separation. Competitive advantages, listed by company. AkadeumUS-based company, founded in 2012. Akadeum offers new non-magnetic technology for cell separation – buoyancy-activated cell sorting (BACS). Buoyancy technology entails microscopic microbubbles, which float on a surface of the liquid after capturing targeted cells. Competitive advantages – simplicity, speed and magnet/ device independence. BioMagnetic SolutionsUS-based company, which offers improved magnetic cell isolation. Company makes ferrofliuds (nano-magnetic liquids)...

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Standardization of apheresis collections for consistent cell product manufacturing

With success and increasing interest to immunocellular therapies, apheresis became the most frequent incoming raw material for product manufacturing.  Everyone, who is involved in day-to-day processing of immunocellular therapy products, very familiar with a big variability of  apheresis collections. But, until now, professionals have not discussed openly manufacturing risks and potential solutions, related to variability of apheresis products. Speakers from two conferences that I’ve attended this week (see here and here), brought up these issues in relation to manufacturing of CAR T-cell products. While product manufacturing process becomes more and more defined, impact of external factors, such as incoming donor material and storage/ delivery (post-manufacturing logistics) are still poorly validated and standardized. These external factors, which have nothing to do with manufacturing, could totally kill your product. Why this issue is coming up more and more right now? While immunocellular therapy is developed in academic institution, the most (if not all) apheresis products get processed. However, significant fraction of patients with hematological malignancies have hugely abnormal hematopoiesis and peripheral blood profile. For example, apheresis product from CLL patient, contained 100 billion cells, could be composed of 99% leukemic blasts. This is extremely hard product to work with if you need to get very pure population of T-cells on day 0 of culture. To resolve apheresis collection variability problem, academics usually develop multiple processing pathways. Nonetheless, some products still may...

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Talks from recent conferences

Many great presentations from three recent conferences were recorded and publicly shared. Here is summary of links. 1. Cells: from Robert Hooke to Cell TherapyThis event was organized by British the Royal Society and took place on October 5-6 in London. Cell Therapy Catapult recorded some talks:Carl June (Upenn) on progress in CAR T-cell therapiesSven Kili (GSK) on involvement of GSK in cell/ gene therapiesBent Jakobsen (Adaptimmune) on cellular immunotherapy of cancerPhilippe Menasché (George Pompidou Hospital) – current state of cardiac cell therapySilviu Itescu (Mesoblast) on company’s progress in clinical trialsJames Shapiro (Alberta Diabetes Institute) on a progress in human islet transplantationAnders Lindahl (U of Gothenburg) – history of chondrocytes transplantation All talks are delivered by pioneers and leaders in their fields! Don’t miss! 2. Stem Cell Meeting on the Mesa 2015This is an annual event, which takes place in California every October. Co-organizer Alliance for Regenerative Medicine, recorder all industry-related talks and shared on their YouTube channel:Featured Speakers & Panels (11 videos)Company presentations (62 videos!)Workshops (4 videos) I’d highly recommend you to watch panels! 3. 2015 Gladstone Fall Symposium: From Stem Cells to CuresGladstone Institute in San Francisco is a magnet for the greatest stem cell scientists. Their Fall Symposium featured 2 speakers: Shinya Yamanaka and Blake Byers. Highly recommended to watch whole video! Tagged as: conference,...

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A protocol for manufacturing of GMP-compliant iPS cell lines

Yesterday, Stem Cell Reports published “must read” paper, which describes manufacturing of GMP-grade iPS cell line for potential clinical use. We saw a few very similar paper titles in in the past, but this one is special. Here is why: This is the first (as claimed by authors) fully GMP-compliant manufacturing protocol for generation of iPS cell master bank. “Fully” means a lot here, because previous protocols were lacking appropriate donor consents, determination of donor eligibility, appropriate process validation steps and quality control testing. It is in open access and it is the most detailed protocol ever published. Even though, the paper describes one process development, it gives a global framework to any cell product developer. Such general principles as donor eligibility, validation and engineering runs, in-process assays and quality control testing were greatly emphasized in the paper. As result of process development at Lonza, drug master file (DMF) was filed with FDA and available for developers. Ready to use DMF for clinical master cell bank means a lot, guys! You can save couple years of your time and tons of money for product and process development if use available iPS line with DMF. Take (buy) it and develop your own unique product from it! You can also hire Lonza to develop your specific master cell bank, using the same processes. This protocol was developed (partly) as “public good”...

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