3D microgels to quantify tumor cell properties and therapy response dynamics.

Tumors contain heterogeneous and dynamic populations of cells that do not all display the fast-proliferating properties that traditional chemotherapies target. There is a need therefore, to develop novel treatment strategies that target diverse tumor cell properties. Identifying therapy combinations is challenging however. Current approaches have relied on cell lines cultured in monolayers with treatment response being assessed using endpoint metabolic assays, which although enable large-scale throughput, do not capture tumor heterogeneity. Here, a 3D in vitro tumor model using micro-molded hydrogels (microgels), the Gels for Live Analysis of Compartmentalized Environments (GLAnCE) platform, is adapted into a 96-well plate format (96-GLAnCE) that integrates patient-derived organoids (PDOs) and is combined with longitudinal automated imaging to address these limitations. Using 96-GLAnCE, two measures of tumor aggressiveness are quantified, tumor cell growth and in situ regrowth after drug treatment, in both cell lines and PDOs. The use of longitudinal image-based readouts enables the identification of tumor cell phenotypes with cell population and subpopulation resolution that cannot be detected by standard bulk-soluble assays. 96-GLAnCE is a versatile and robust platform that combines 3D-ECM based models, PDOs, and real-time assay readouts, to provide an additional tool for pre-clinical anti-cancer drug discovery for the identification of novel targets with translatable clinical significance.

A new field test to estimate the aerobic and anaerobic thresholds and maximum parameters.

Evaluation of cardiorespiratory parameters is important in athletic population in order to monitor the training status and define training intensities. The aim of this study was to validate an easy-to-perform running test called RABIT® (Running Advisor Billat Training) for detecting aerobic (AerT) and anaerobic (AnT) threshold and maximum parameters. Fifteen trained runners completed a graded (GRAD) and RABIT test (four self-selected pace steps: (i) 10 minutes at free warm-up pace, (ii) 5 minutes at medium pace, (iii) 3 minutes at hard pace, (iv) 10 minutes at easy pace). We compared the cardiorespiratory parameters and running speed of the RABIT with those corresponding to AerT, AnT or maximum parameters obtained by the GRAD. The ⩒O2max, HRmax, RERmax and running speed max measured during the 3-minute hard pace of the RABIT were not statistically different from the maximum parameters measured during GRAD (p > 0.05). The ⩒O2, HR and RER measured during the medium and easy pace of the RABIT were not significantly different from the AnT and AerT parameters measured during GRAD. In conclusion, RABIT was validated for all the maximum parameters and for most of Ant- and AerT-related parameters and then it might be used for detecting training zones in athletes.