Structure and Properties of Sulfonated Pentablock Terpolymer Films as a Function of Wet–Dry Cycles

The structure and properties of poly­(<i>tert-</i>butylstyrene-<i>b</i>-hydrogenated isoprene-<i>b</i>-sulfonated styrene-<i>b</i>-hydrogenated isoprene-<i>b</i>-<i>tert-</i>butylstyrene) (tBS-HI-SS-HI-tBS) films were investigated as a function of “wet–dry cycles”, where one “cycle” is defined as a 24 h soak in deionized water followed by a 24 h drying period in air. Films were characterized with a variety of complementary measurements that include X-ray scattering, infrared spectroscopy, water uptake, impedance spectroscopy, and tensile tests. We find that cycling drives a structural transition toward increasingly interconnected SS domains, which is favorable for water and ion transport. However, cycling can also induce mechanical deformations that reduce ductility, swelling, and water uptake. The significance of this trade-off is illustrated by comparing the properties for two film thicknesses as a function of cycle number: The ductility of thinner films (15 μm) is lost after four cycles, an effect that is correlated with the appearance of macroscale buckles, and the extent of swelling is also reduced. Therefore, the transport properties reflect a balance between the increased SS domain interactions and reduced water content. The ductility in thick films (30 μm) also declines with cycling, but to a lesser extent, and these systems retain their ability to swell through six cycles. Therefore, the transition to a network-like SS structure enhances both water uptake and transport. These systematic studies demonstrate that successive wet–dry cycles can lead to complex changes in the performance of amphiphilic block copolymer films, which may complicate their design for applications in water treatment or proton-conducting layers in electrochemical devices

Application of a Drug-Induced Apoptosis Assay to Identify Treatment Strategies in Recurrent or Metastatic Breast Cancer

<div><p>Background</p><p>A drug-induced apoptosis assay has been developed to determine which chemotherapy drugs or regimens can produce higher cell killing in vitro. This study was done to determine if this assay could be performed in patients with recurrent or metastatic breast cancer patients, to characterize the patterns of drug-induced apoptosis, and to evaluate the clinical utility of the assay. A secondary goal was to correlate assay use with clinical outcomes.</p><p>Methods</p><p>In a prospective, non-blinded, multi institutional controlled trial, 30 evaluable patients with recurrent or metastatic breast cancer who were treated with chemotherapy had tumor samples submitted for the MiCK drug-induced apoptosis assay. After receiving results within 72 hours after biopsy, physicians could use the test to determine therapy (users), or elect to not use the test (non-users).</p><p>Results</p><p>The assay was able to characterize drug-induced apoptosis in tumor specimens from breast cancer patients and identified which drugs or combinations gave highest levels of apoptosis. Patterns of drug activity were also analyzed in triple negative breast cancer. Different drugs from a single class of agents often produced significantly different amounts of apoptosis. Physician frequently (73%) used the assay to help select chemotherapy treatments in patients, Patients whose physicians were users had a higher response (CR+PR) rate compared to non-users (38.1% vs 0%, p = 0.04) and a higher disease control (CR+PR+Stable) rate (81% vs 25%, p<0.01). Time to relapse was longer in users 7.4 mo compared to non-users 2.2 mo (p<0.01).</p><p>Conclusions</p><p>The MiCK assay can be performed in breast cancer specimens, and results are often used by physicians in breast cancer patients with recurrent or metastatic disease. These results from a good laboratory phase II study can be the basis for a future larger prospective multicenter study to more definitively establish the value of the assay.</p><p>Trial Registration</p><p>Clinicaltrials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT00901264" target="_blank">NCT00901264</a></p></div

In Vitro Drug Induced Apoptosis in Triple Negative Breast Cancer Patients.

<p>In Vitro Drug Induced Apoptosis in Triple Negative Breast Cancer Patients.</p

Patient Characteristics.

<p>Patient Characteristics.</p

In Vitro Drug Induced Apoptosis by Agent in all Patients.

<p>In Vitro Drug Induced Apoptosis by Agent in all Patients.</p

Time to recurrence in patients with recurrent or metastatic breast cancer.

<p>Blue curve, patients whose physician used the MiCK assay. Red curve, patients whose physician did not use the MiCK assay.</p

Correlation of Response with use of the Mick Assay.

<p>Correlation of Response with use of the Mick Assay.</p

CONSORT Flow Diagram.

<p>CONSORT Flow Diagram.</p

Dosimetry and analysis of wild dogs.

(a) 21/288 animals surveyed as part of the 2017 and 2018 programs had external contamination above the threshold (100 cpm on Ludlum 26-2, equivalent to 95 Bq per 100 cm2 area, 90Sr). The distribution of this contamination is shown here. (b) Scatter plot of the animal body-burden as a function of body mass for the 2017 (peach) and 2018 (purple) campaign. Animals in 2017 with activity less than 100 Bq/kg are excluded. Animals in 2018 with activity less than 30 Bq/kg are excluded. External contamination is shown in this plot using squares, the size of which is correlated to the reported measurement in counts per minute using the Ludlum 26-2 probe on contact.</p

Instances of internal activity detection as determined by the whole-body counting experiment.

Note that the 2017 experiment had a detection threshold of approximately 100 Bq/kg, whereas the 2018 revision was sensitive to approximately 30 Bq/kg.</p