Sperm banking before gonadotoxic treatment: is it worth the effort?

We aimed to compare the sperm quality in different cancer types and benign diseases before gonadotoxic treatment, and assess the usage rate of cryopreserved sperm for assisted reproductive treatment (ART). This retrospective study was conducted at two university clinics between January 2008 and July 2018. A total of 545 patients suffering from cancer or benign diseases were included in the study. The pretreatment sperm analyses were based on the World Health Organization (WHO) guidelines. Patients with testicular malignancy (TM) showed a significantly lower sperm count (median [interquartile range]: 18.7 × 106 [5.3 × 106-43.0 × 106] ml-1; P = 0.03) as well as total sperm count (42.4 × 106 [13.3 × 106-108.5 × 106] per ejaculate; P = 0.007) compared to other malignant and benign diseases. In addition, patients with nonseminomatous TM showed the lowest sperm count (14.3 × 106 [6.0 × 106-29.9 × 106] ml-1, vs seminomas: 16.5 × 106 [4.6 × 106-20.3 × 106] ml-1; P = 0.001). With reference to the WHO 2010 guidelines, approximately 48.0% of the patients with TM and 23.0% with hematological malignancies (HM) had oligozoospermia. During the observation period, only 29 patients (5.3%) used their frozen sperms for 48 ART cycles, resulting in 15 clinical pregnancies and 10 live births. The sperm quality varies with the type of underlying disease, with TM and HM patients showing the lowest sperm counts. Due to the observed low usage rate of cryopreserved sperm, further patient interviews and sperm analyses should be included in the routine oncologic protocols to avoid unnecessary storage expenses. However, sperm banking is worth the effort as it provides hope for men who cannot reproduce naturally after gonadotoxic treatment.

Experimental benchmark data and systematic evaluation of two a posteriori, polarizable-continuum corrections for vertical excitation energies in solution.

We report the implementation and evaluation of a perturbative, density-based correction scheme for vertical excitation energies calculated in the framework of a polarizable continuum model (PCM). Because the proposed first-order correction terms depend solely on the zeroth-order excited-state density, a transfer of the approach to any configuration interaction-type excited-state method is straightforward. Employing the algebraic-diagrammatic construction (ADC) scheme of up to third order as well as time-dependent density-functional theory (TD-DFT), we demonstrate and evaluate the approach. For this purpose, we assembled a set of experimental benchmark data for solvatochromism in molecules (xBDSM) containing 44 gas-phase to solvent shifts for 17 molecules. These data are compared to solvent shifts calculated at the ADC(1), ADC(2), ADC(3/2), and TD-DFT/LRC-ωPBE levels of theory in combination with state-specific as well as linear-response type PCM-based correction schemes. Some unexpected trends and differences between TD-DFT, the levels of ADC, and variants of the PCM are observed and discussed. The most accurate combinations reproduce experimental solvent shifts resulting from the bulk electrostatic interaction with maximum errors in the order of 50 meV and a mean absolute deviation of 20-30 meV for the xBDSM set.

Novel ultrathin poly(ethylene glycol) films as flexible platform for biological applications and plasmonics.

We present a novel approach to prepare ultrathin, biocompatible films based on cross-linking of multi-functionalized, star-branched poly(ethylene glycols) (STAR-PEGs) with tunable film thicknesses of 4-200 nm. A two-component mixture of amine- and epoxy-terminated four-arm STAR-PEGs (MN=2000 g/mol) was spin-coated on a flat substrate. Gentle heating induced an extensive chemical cross-linking of the macromonomers, resulting in a stable, hydrogel-like film with a density close to that of bulk PEG material. The cross-linking process could be monitored in situ, exhibiting the expected kinetics. The films revealed pronounced swelling behavior, which was fully reversible and could be precisely controlled. Additionally, they provided a high affinity to citrate-stabilized gold nanoparticles (AuNP) that could be adsorbed with high densities into the PEG matrix from an aqueous solution. These novel PEG/AuNP composite films offer interesting and potentially useful optical properties. The adsorption could also be performed in a lithographic fashion, resulting in AuNP patterns imbedded into the PEG matrix.