Polyurethane Based Materials for the Production of Biomedical Materials

Polyurethanes (PUs) composed by hard and soft segments have been extensively used in the manufacturing of biocompatible prosthesis and medical devices. A broad variety of PUs can be obtained by modifying the balance between both segments. In the present work, different basically-flexible PUs have been prepared by employing different combinations of aliphatic hexamethylene diisocyanate, poly(ethylene glycol) (Mw 400 Da), poly(ϵ-caprolactone) diol (Mw 530 Da), and 1,4-butanediol. Thermal analysis of the synthesized PUs demonstrated high thermal stability and the assumption of glassy state well below room temperature, in agreement with their marked flexibility. Morphological characterization of PUs films indicated that films prepared by spin coating were smoother and more homogeneous than those obtained by casting. Biological assays performed by using 3T3/BALB-C mouse embryo fibroblast cell line confirmed the absence of toxicity and hence the biocompatibility of PU-films.     

Seasonal Changes in Essential Oil Constituents of Cystoseira compressa: First Report

Marine macroalgae are well known to release a wide spectrum of volatile organic components, the release of which is affected by environmental factors. This paper aimed to identify the essential oil (EO) compounds of the brown algae Cystoseira compressa collected in the Adriatic Sea monthly, from May until August. EOs were isolated by hydrodistillation using a Clavenger-type apparatus and analyzed by gas chromatography coupled with mass spectrometry (GC–MS). One hundred four compounds were identified in the volatile fraction of C. compressa, accounting for 84.37–89.43% of the total oil. Samples from May, June, and July were characterized by a high share of fatty acids (56, 69, and 34% respectively) with palmitic acid being the dominant one, while in the August sample, a high content of alcohols (mainly phytol and oleyl alcohol) was found. Changes in the other minor components, which could be important for the overall aroma and biological activities of the algal samples, have also been noted during the vegetation periods. The results of this paper contribute to studies of algal EOs and present the first report on C. compressa EOs.     

A New Kid on the Block: Sacituzumab Govitecan for the Treatment of Breast Cancer and Other Solid Tumors

Human trophoblast cell-surface antigen-2 (Trop-2) is a membrane glycoprotein involved in cell proliferation and motility, frequently overexpressed in epithelial tumors. Thus, it represents an attractive target for anticancer therapies. Sacituzumab govitecan (SG) is a third-generation antibody-drug conjugate, consisting of an anti-Trop-2 monoclonal antibody (hRS7), a hydrolyzable linker, and a cytotoxin (SN38), which inhibits topoisomerase 1. Specific pharmacological features, such as the high antibody to payload ratio, the ultra-toxic nature of SN38, and the capacity to kill surrounding tumor cells (the bystander effect), make SG a very promising drug for cancer treatment. Indeed, unprecedented results have been observed with SG in patients with heavily pretreated advanced triple-negative breast cancer and urothelial carcinomas, and the drug has already received approval for these indications. These results are coupled with a manageable toxicity profile, with neutropenia and diarrhea as the most frequent adverse events, mainly of grades 1–2. While several trials are exploring SG activity in different tumor types and settings, potential biomarkers of response are under investigation. Among these, Trop-2 overexpression and the presence of BRCA1/2 mutations seem to be the most promising. We review the available literature concerning SG, with a focus on its toxicity spectrum and possible biomarkers of its response.     

Amphiphilic pentablock copolymers and their blends with PDMS for antibiofouling coatings

Well‐defined amphiphilic pentablock copolymers Siy‐(EGx‐FAz)₂ composed of polysiloxane (Si), polyethylene glycol (EG), and perfluorohexylethyl polyacrylate (FA) blocks are synthesized by ATRP of FA monomer starting from a difunctional bromo‐terminated macroinitiator. Diblock copolymers EGx‐FAz are also synthesized as model systems. The block copolymers are used, either alone or blended with a PDMS matrix in varied loadings, to prepare antibiofouling coatings. Angle‐resolved XPS and contact angle measurements show that the coating surface is highly enriched in fluorine content but undergoes reconstruction after contact with water. Protein adsorption experiments with human serum albumin and calf serum highlight that diblock copolymers resist protein adhesion better than do pentablock copolymers. Blending of the pentablock copolymer with PDMS results in increased protein adsorption. By contrast, the PDMS‐matrix coatings show high removal percentages of sporelings of the green fouling alga Ulva linza. © 2015 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 2015 , 53, 1213–1225     

Effective computational modeling of erythrocyte electro-deformation

Due to its crucial role in pathophysiology, erythrocyte deformability represents a subject of intense experimental and modeling research. Here a computational approach to electro-deformation for erythrocyte mechanical characterization is presented. Strong points of the proposed strategy are: (1) an accurate computation of the mechanical actions induced on the cell by the electric field, (2) a microstructurally-based continuum model of the erythrocyte mechanical behavior, (3) an original rotation-free shell finite element, especially suited to the application in hand. As proved by the numerical results, the developed tool is effective and sound, and can foster the role of electro-deformation in single-cell mechanical phenotyping.     

Linear polarization scans for resonant X‐ray diffraction with a double‐phase‐plate configuration

An in‐vacuum double‐phase‐plate diffractometer for performing polarization scans combined with resonant X‐ray diffraction experiments is presented. The use of two phase plates enables the correction of some of the aberration effects owing to the divergence of the beam and its energy spread. A higher rate of rotated polarization is thus obtained in comparison with a system with only a single retarder. Consequently, thinner phase plates can be used to obtain the required rotated polarization rate. These results are particularly interesting for applications at low energy (e.g. 4 keV) where the absorption owing to the phase plate(s) plays a key role in the feasibility of these experiments. Measurements by means of polarization scans at the uranium M₄ edge on UO₂ enable the contributions of the magnetic and quadrupole ordering in the material to be disentangled.