Toward Absolute Chemical Composition Distribution Measurement of Polyolefins by High-Temperature Liquid Chromatography Hyphenated with Infrared Absorbance and Light Scattering Detectors

Chemical composition distribution (CCD) is a fundamental metric for representing molecular structures of copolymers in addition to molecular weight distribution (MWD). Solvent gradient interaction chromatography (SGIC) is commonly used to separate copolymers by chemical composition in order to obtain CCD. The separation of polymer in SGIC is, however, not only affected by chemical composition but also by molecular weight and architecture. The ability to measure composition and MW simultaneously after separation would be beneficial for understanding the impact of different factors and deriving true CCD. In this study, comprehensive two-dimensional chromatography (2D) was coupled with infrared absorbance (IR5) and light scattering (LS) detectors for characterization of ethylene–propylene copolymers. Polymers were first separated by SGIC as the first dimension chromatography (D1). The separated fractions were then characterized by the second dimension (D2) size exclusion chromatography (SEC) with IR5 and LS detectors. The concentrations and compositions of the separated fractions were measured online using the IR5 detector. The MWs of the fractions were measured by the ratio of LS to IR5 signals. A metric was derived from online concentration and composition data to represent CCD breadth. The metric was shown to be independent of separation gradients for an “absolute” measurement of CCD breadth. By combining online composition and MW data, the relationship of MW as a function of chemical composition was obtained. This relationship was qualitatively consistent with the results by SEC coupled to IR5, which measures chemical composition as a function of logMW. The simultaneous measurements of composition and MW give the opportunity to study the SGIC separation mechanism and derive chain architectural characteristics of polymer chains

Additional file 2: Figure S2. of Radiotherapy enhances natural killer cell cytotoxicity and localization in pre-clinical canine sarcomas and first-in-dog clinical trial

Validation of ALDH as a CSC Marker in Dog PDX Tumors. A. A dog sarcoma PDX tumor was allowed to grow to ~ 20 mm in maximal dimension. The tumor was then excised and digested into single cell suspension. B. Tumor cells were sorted by flow cytometry into ALDHbright and ALDHdim populations. 2 × 105 purified cells were implanted subcutaneously into contralateral flanks of NSG mice (N = 4) and allowed to grow. ALDHbright cells established tumors faster and were more rapidly fatal. * P < 0.05 via one-way ANOVA with Tukey’s post-test. C. Representative photograph showing difference in tumor formation between ALDHbright and ALDHdim sarcoma PDX #465049 cells implanted subcutaneously in NSG mice. (TIFF 890 kb

Additional file 1: Figure S1. of Radiotherapy enhances natural killer cell cytotoxicity and localization in pre-clinical canine sarcomas and first-in-dog clinical trial

Canine Lymphokine Activated Killer Cells Respond to Human Cytokines and Can Target Dog Osteosarcoma Cells. Dog PBMCs were obtained from healthy dogs and laboratory beagles. Adherent lymphocytes were isolated by standard techniques and cultured with short term rhIL-12/15/18 for 24 h followed by co-culture with low dose rhIL-2 (100 IU/mL) for 7 days. Cells were assessed for expansion, viability, and cytotoxicity at various time points. A. From 4 donors, the mean number of ALAKs at day 0 was 12 × 106 ALAKs. After 7 days in culture, the mean number of recovered ALAKs was 23 ± 9.8 × 106 cells. B. After 7 days in culture, the mean fold expansion of ALAKs was 1.8 ± 0.3. C. Mean viability decreased from 97.7 ± 1.8% on day 0 to 92.3 ± 4.7% on day 7. D. Using PBMCs from a 4-year old healthy unknown breed, we observed that cytotoxicity against OSA-1 targets at day 7 was significantly greater after co-culture with recombinant human cytokines IL-12 (10 ng/mL), IL-15 (10 ng/mL), and IL-18 (10 ng/mL) compared to rhIL-2 alone (5000 IU/mL). E. Using ALAKS expanded with rhIL-12/15/18 from a healthy 7-year old Rat Terrier, we performed a 12–16 h killing assay at the indicated effector:target ratios with OSCA-32. Dose-dependent cytotoxicity was again observed. **** P < 0.0001 via one-way ANOVA with Tukey’s post-test. (TIFF 104 kb