Partition behavior of CD133+stem cells from human umbilical cord blood in aqueous two-phase systems: In route to establish novel stem cell primary recovery strategies

Generation of MCF-7 Spheroids in Polyethylene Glycol-Dextran Droplets for Cancer Niche Studies Using Aqueous Two-Phase System-3D Platforms

Cell-based aqueous two-phase system (ATPS) applications involve the construction of 3D cultures encapsulating cells in polyethylene glycol (PEG)-dextran (DEX) droplets due to their low interfacial tension. This technology has enabled cell patterning in a controlled-defined shape giving rise to specific cell microenvironments. The present work aims to encapsulate MCF-7 cancer cells in ATPS droplets evaluating four different compositions of PEG-DEX, construction Strategies A (droplet added), B (immersed), or C (covered), and two cell densities (5000 and 10,000 cells/µL) during a 24 h incubation time using 96-well plates. The smallest cell-containing DEX droplets showed a mid-range value of 1.05 ± 0.33 mm using Strategy C whereas the largest of 1.46 ± 0.49 mm in Strategy B. However, Strategy A was associated with higher rates of circularity. After 24 h, MCF-7 spheroids were formed in all PEG-DEX systems showing a diameter size ranging from 0.10 to 0.65 mm. Their circularity was higher in low cell densities. Higher rates of cell viability were obtained in PEG 35,000-DEX 500,000 systems for a period of 4 days showing tumor-specific traits compared to 2D control. This work demonstrates practical strategies for 3D model construction for cancer niche for future drug screening studies using basic laboratory equipment.

Past, Present, and Future of Affinity-based Cell Separation Technologies

Progress in cell purification technology is critical to increase the availability of viable cells for therapeutic, diagnostic, and research applications. A variety of techniques are now available for cell separation, ranging from non-affinity methods such as density gradient centrifugation, dielectrophoresis, and filtration, to affinity methods such as chromatography, two-phase partitioning, and magnetic-/fluorescence-assisted cell sorting. For clinical and analytical procedures that require highly purified cells, the choice of cell purification method is crucial, since every method offers a different balance between yield, purity, and bioactivity of the cell product. For most applications, the requisite purity is only achievable through affinity methods, owing to the high target specificity that they grant. In this review, we discuss past and current methods for developing cell-targeting affinity ligands and their application in cell purification, along with the benefits and challenges associated with different purification formats. We further present new technologies, like stimuli-responsive ligands and parallelized microfluidic devices, towards improving the viability and throughput of cell products for tissue engineering and regenerative medicine. Our comparative analysis provides guidance in the multifarious landscape of cell separation techniques and highlights new technologies that are poised to play a key role in the future of cell purification in clinical settings and the biotech industry. STATEMENT OF SIGNIFICANCE: Technologies for cell purification have served science, medicine, and industrial biotechnology and biomanufacturing for decades. This review presents a comprehensive survey of this field by highlighting the scope and relevance of all known methods for cell isolation, old and new alike. The first section covers the main classes of target cells and compares traditional non-affinity and affinity-based purification techniques, focusing on established ligands and chromatographic formats. The second section presents an excursus of affinity-based pseudo-chromatographic and non-chromatographic technologies, especially focusing on magnetic-activated cell sorting (MACS) and fluorescence-activated cell sorting (FACS). Finally, the third section presents an overview of new technologies and emerging trends, highlighting how the progress in chemical, material, and microfluidic sciences has opened new exciting avenues towards high-throughput and high-purity cell isolation processes. This review is designed to guide scientists and engineers in their choice of suitable cell purification techniques for research or bioprocessing needs.

Economic evaluation of the primary recovery of tetracycline with traditional and novel aqueous two-phase systems

Antibiotics are a key pharmaceutical to inhibit growth or kill microorganisms. They represent a profitable market and, in particular, tetracycline has been listed as an essential medicine by the WHO. Therefore it is important to improve their production processes. Recently novel and traditional aqueous two-phase systems for the extraction have been developed with positive results. The present work performs an economic analysis of the production and recovery of tetracycline through the use of several ATPS through bioprocess modeling using specialized software (BioSolve, Biopharm Services Ltd, UK) to determine production costs per gram (CoG/g). First, a virtual model was constructed using published data on the recovery of tetracycline and extended to incorporate uncertainties. To determine how the model behaved, a sensitivity analysis and Monte Carlo simulations were performed. Results showed that ATPS formed by cholinium chloride/K₃PO₄ was the best option to recover tetracycline, as it had the lowest CoG/g (US$ 672.83/g), offered the highest recovery yield (92.42%), second best sample input capacity (45% of the ATPS composition) and one of the lowest materials contribution to cost. The ionic liquid-based method of ATPS is a promising alternative for recovering tetracycline from fermentation broth.