Liquid–liquid phase separation between aqueous solutions containing two incompatible polymers, a polymer and a salt, or a polymer and a surfactant, has been exploited for a wide variety of biotechnology applications throughout the years. While many applications for aqueous two‐phase systems fall within the realm of separation science, the ability to partition many different materials within these systems, coupled with recent advances in materials science and liquid handling, has allowed bioengineers to imagine new applications. This progress report provides an overview of the history and key properties of aqueous two‐phase systems to lend context to how these materials have progressed to modern applications such as cellular micropatterning and bioprinting, high‐throughput 3D tissue assembly, microscale biomolecular assay development, facilitation of cell separation and microcapsule production using microfluidic devices, and synthetic biology. Future directions and present limitations and design considerations of this adaptable and promising toolkit for biomolecule and cellular manipulation are further evaluated.

Summary Lycopene exhibits strong antioxidant activity due to its unsaturated molecular bonds, which also contributes to its susceptibility for degradation. Encapsulation techniques can reduce lycopene degradation, increasing its potential applications in functional foods and nutraceuticals. The objective of this study was to optimise the encapsulation of lycopene from watermelon in alginate microparticles using the inverse gelation method. Box–Behnken design was used for the optimisation of three variables: concentrations of alginate (w/v %) and CaCl2 (g L−1), and gelation time (min). Two types of alginate were investigated (low viscosity and high viscosity) and optimised separately using encapsulation efficiency and loading capacity as responses. Results indicated that the models had a good fit to the experimental data and the optimal conditions varied depending on the type of alginate. In general, particles prepared with low‐viscosity alginate exhibited higher encapsulation efficiency and loading capacity and could be used for further research.

SH‐SY5Y and LUHMES cell lines are widely used as model systems for studying neurotoxicity. Most of the existing data regarding the sensitivity of these cell lines to neurotoxicants have been recorded from cells growing as two‐dimensional (2D) cultures on the surface of glass or plastic. With the emergence of 3D culture platforms designed to better represent native tissue, there is a growing need to compare the toxicology of neurons grown in 3D environments to those grown in 2D to better understand the impact that culture environment has on toxicant sensitivity. Here, a simple 3D culture method was used to assess the impact of growth environment on the sensitivity of SH‐SY5Y cells and LUHMES cells to MPP+, tunicamycin, and epoxomicin, three neurotoxicants that have been previously used to generate experimental models for studying Parkinson's disease pathogenesis. SH‐SY5Y cell viability following treatment with these three toxicants was significantly lower in 2D cultures as compared to 3D cultures. On the contrary, LUHMES cells did not show significant differences between growth conditions for any of the toxicants examined. However, LUHMES cells were more sensitive to MPP+, tunicamycin, and epoxomicin than SH‐SY5Y cells. Thus, both the choice of cell line and the choice of growth environment must be considered when interpreting in vitro neurotoxicity data.

Background: Leukopenia occurs frequently following kidney transplantation and is associated with adverse clinical outcomes including increased infectious risk. In this study we sought to characterize the causes and complications of leukopenia following kidney transplantation. Methods: In a cohort of adult patients (≥18 years) who underwent kidney transplant from Jan 2006-Dec 2017, we used univariable Cox proportional Hazards models to identify predictors of post-transplant leukopenia (WBC < 3500 mm3). Factors associated with post-transplant leukopenia were then included in a multivariable backwards stepwise selection process to create a prediction model for the outcome of interest. Cox regression analyses were subsequently used to determine if post-transplant leukopenia was associated with complications. Results: Of 388 recipients, 152 (39%) developed posttransplant leukopenia. Factors associated with leukopenia included antithymocyte globulin as induction therapy (HR 3.32, 95% CI 2.25-4.91), valganciclovir (HR 1.84, 95% CI 1.25-2.70), tacrolimus (HR 3.05, 95% CI 1.08-8.55), prior blood transfusion (HR 1.17 per unit, 95% CI 1.09- 1.25), and donor age (HR 1.02 per year, 95% CI 1.00-1.03). Cytomegalovirus infection occurred in 26 patients with leukopenia (17.1%). Other than cytomegalovirus, leukopenia was not associated with posttransplant complications. Conclusion: Leukopenia commonly occurred posttransplant and was associated with modifiable and non-modifiable pretransplant factors.

Aqueous two-phase systems (ATPSs) have numerous applications in separation science, and more recently, in bioassays enabled by the solution micropatterning of cells. The most frequently used ATPS in these applications is the polyethylene glycol (PEG)-dextran (Dex) system, as the polymers that form this ATPS have been extensively characterized in terms of their physicochemical properties. However, in addition to this well-known system, there exist many other ATPSs with properties that may be exploited to improve upon the PEG-dextran system for specific applications. One of these underexplored systems is the ATPS formed from PEG/polyethylene oxide (PEO) and albumin. In this article, we characterize the phase separation of PEG (35 kDa) and polyethylene oxide (PEO) (200, 900, and 4,000 kDa) with bovine serum albumin (BSA). We describe the microscopic emulsion behavior of these systems in the presence of NaCl and compounds (NaHCO 3 , NaH 2 PO 4 , and HEPES) commonly used in buffer solutions and cell culture media. We further demonstrate that PEG- and PEO-albumin systems can be used in place of the PEG-dextran system for confinement of suspension-cultured cells (Jurkat T cells and RPMI-8226 B cells). Cell viability and morphology are examined for various polymer formulations relative to the commonly used PEG 35 kDa-Dex 500 kDa system and polymer-free cell culture medium. In addition, we examine cell activation for various phase-separating medium components by measuring IL-2 and IL-6 secretion. We demonstrate that we can confine immune cells and cytokines in the PEG-BSA system, and that this system can be employed to screen immune responses by enzyme-linked immunospot (ELISpot) assay. This new system represents a promising ATPS formulation for applications where low levels of baseline cell activation are required, for instance, when culturing immune cells.

Conclusion: This study demonstrated that both PEG and Dex solutions can confine immune cells within polymer solution microreactors without significantly compromising cell viability, proliferation, and metabolic activity. Using this system to screen immunotherapy agents may facilitate the development of more effective vaccine adjuvants formulations and other immunotherapies.

Lista de AbreviaturasAAPH -2,2`-azobis(2-amidinopropano) dihidroclorado BHT -Butil-hidróxi-tolueno CCDC -Cromatografia em camada delgada comparativa CG-MS -Cromatografia gasosa acoplada ao detector de massas CLAE-UV -Cromatografia líquida de alta eficiência com detecção no ultravioleta CLAE-DAD -Cromatografia líquida de alta eficiência com detector de arranjo de diodos DBV-IB -Departamento de Biologia Vegetal -Instituto de Biologiade massas ESI-MS -Espectrometria de massa com injeção por eletron spray FCFRP -Faculdade de Ciências Farmacêuticas de Ribeirão Preto FCR -Folin-Ciocalteu reagent FL -Fluoresceína GAE -Ácido gálico equivalente IC 50 -Concentração que inibe 50% IV -Infravermelho LC-MS -Cromatografia líquida acoplada à espectrometria de massas MEV -Microscopia eletrônica de varredura MS -Espectrometria de massas NP/PEG -Natural Products-Polyethyleneglycolreagent ORAC -Oxygen radical absorbance capacity PEAD -Polietileno de alta densidade RMN 13 C -Ressonância magnética nuclear do 13 C RMN 1 H -Ressonância magnética nuclear do 1 H TE -Trolox equivalente TEAC -Trolox equivalent antioxidant capacity

An aqueous two-phase system was used to reduce reagent volumes and optical crosstalk for a low-cost single sandwich enzyme-linked immunoassay.