Use of pyrazoles as ligands greatly enhances the catalytic activity of titanium iso-propoxide for the ring-opening polymerization of l-lactide: a cooperation effect

Using TiOⁱPr₄ with a pyrazole ligand for one-pot LA polymerization improved catalytic activity compared with using TiOⁱPr₄ only. At 60 °C, TiOⁱPr₄ with ^furPz exhibited a higher catalytic activity (approximately 3-fold) than TiOⁱPr₄. At room temperature, TiOⁱPr₄ with ^BuPz exhibited a higher catalytic activity (approximately 17-fold) than TiOⁱPr₄. High molecular mass PLA (M_nGPC = 51 100, and Đ = 1.10) could be produced by using TiOⁱPr₄ with ^furPz in melt polymerization ([TiOⁱPr₄] : [^furPz] = 1000 : 1 : 1 at 100 °C, 240 min). The crystal structure of ^MePz₂Ti₂OⁱPr₇ revealed the cooperative activation between two Ti atoms during LA polymerization.

Using TiOⁱPr₄ with a pyrazole ligand for one-pot LA polymerization improved catalytic activity compared with using TiOⁱPr₄ only.     

Anomalous boron isotope effects on electronic structure and lattice dynamics of CuB2O4

Copper metaborate had a unique crystal structure and exhibited noteworthy magnetic phase transitions at 21 and 10 K. The electronic structure and lattice dynamics of copper metaborate Cu¹¹B₂O₄ single crystals were investigated and compared with the optical properties of CuB₂O₄, to assess the boron isotope effect. The optical absorption spectrum at room temperature revealed two charge-transfer bands at approximately 4.30 and 5.21 eV with an extrapolated direct optical band gap of 3.16 ± 0.07 eV. Compared with the data on CuB₂O₄, the electronic transitions were shifted to lower energies upon the replacement of a heavier boron isotope. The band gap was also determined to be lower in Cu¹¹B₂O₄. Anomalies in the temperature dependence of the optical band gap were observed below 21 K. Furthermore, 38 Raman-active phonon modes were identified in the room-temperature Raman scattering spectrum of Cu¹¹B₂O₄, which were also observed in CuB₂O₄ with a shift to lower frequencies. No broadening caused by isotopic changes was observed. As the temperature decreased, phonon frequencies shifted to higher wavenumbers and the linewidth decreased. Anomalous softening in the Raman peaks below 21 K was also revealed.

Copper metaborate had a unique crystal structure and exhibited noteworthy magnetic phase transitions at 21 and 10 K.     

Parameter control and property analysis in the preparation of platinum iodide nanocolloids through the electrical spark discharge method

This study employed the electrical spark discharge method to prepare platinum iodide nanocolloids at normal temperature and pressure. Wires composed of 99.5% platinum were applied as the electrodes, and 250 ppm liquid iodine was employed as the dielectric fluid. An electric discharge machine was applied to generate cyclic direct current pulse power between the electrodes. Five sets of turn-on and turn-off time (T_on–T_off) parameters, namely 10–10, 30–30, 50–50, 70–70, and 90–90 μs, were implemented to identify the optimal nanocolloid preparation conditions. An ultraviolet-visible spectroscope, a Zetasizer, and a transmission electron microscope were used to examine the nanocolloids'' properties. The results revealed that the T_on–T_off parameter set of 10–10 μs was the most ideal setting for platinum iodide nanocolloid preparation. With this parameter set, the characteristic wavelengths of the nanocolloid were 285 and 350 nm, respectively; its absorbance values were 0.481 and 0.425, respectively; and its zeta potential and particle size were −30.3 mV and 61.88 nm, respectively. This parameter set yielded maximized absorbance, satisfactory suspension stability, and minimized nanoparticle sizes for the nanocolloid.

This study employed the electrical spark discharge method to prepare platinum iodide nanocolloids at normal temperature and pressure.     

Ultrasound-mediated delivery of RGD-conjugated nanobubbles loaded with fingolimod and superparamagnetic iron oxide nanoparticles: targeting hepatocellular carcinoma and enhancing magnetic resonance imaging

Nanobubbles (NBs) are considered to be a new generation of ultrasound-responsive nanocarriers that can effectively target tumors, accurately release multi-drugs at desired locations, as well as simultaneously perform diagnosis and treatment. In this study, we designed theranostic NBs (FTY720@SPION/PFP/RGD-NBs) composed of RGD-modified liposomes as the shell, and perflenapent (PFP), superparamagnetic iron oxide nanoparticles (SPION), and fingolimod (2-amino-2[2-(4-octylphenyl)ethyl]-1,3-propanediol, FTY720) encapsulated as the core. The prepared FTY720@SPION/PFP/RGD-NBs were black spheres with a diameter range of 160–220 nm, eligible for enhanced permeability and retention (EPR) effects. The calculated average drug loading efficiency (LE) and encapsulation efficiency (EE) of the FTY720@SPION/PFP/RGD-NBs were 9.18 ± 0.61% and 88.26 ± 2.31%, respectively. With the promotion of low-intensity focused ultrasound (LIFU), the amount and the rate of FTY720 released from the prepared NB complex were enhanced when compared to the samples without LIFU treatment. In vitro magnetic resonance imaging (MRI) trials showed that the prepared FTY720@SPION/PFP/RGD-NBs had a high relaxation rate and MRI T2-weighted imaging (T2WI) scanning sensitivity conditions. The cell viability studies demonstrated that both HepG2 and Huh7 cells co-cultured with FTY720@SPION/PFP/RGD-NB (100 μg mL⁻¹) + LIFU treatment had the lowest survival rate compared with the other groups at 24 h and 48 h, showing that FTY720@SPION/PFP/RGD-NB had the strongest anti-tumor efficiency among the prepared NBs. The cytotoxicity study also demonstrated that the prepared NBs had low toxicity to normal fibroblast 3T3 cells. Cellular uptake studies further indicated that both LIFU treatment and RGD modification could effectively improve the tumor-targeted effects, thereby enhancing the antitumor efficacy. The qRT-PCR results indicated that LIFU-mediated FTY720@SPION/PFP/RGD-NB could significantly cause the activation of Caspase3, Caspase9 and p53 compared to the control group, inducing HepG2 apoptosis. These results together indicated that FTY720@SPION/PFP/RGD-NBs combined with LIFU may serve as a multifunctional drug delivery platform for hepatocellular carcinoma treatment and provide a new strategy for tumor visualization by MRI.

Nanobubbles (NBs) are considered to be a new generation of ultrasound-responsive nanocarriers that can effectively target tumors, accurately release multi-drugs at desired locations, as well as simultaneously perform diagnosis and treatment.     

Revolutionizing technologies of nanomicelles for combinatorial anticancer drug delivery

Archives of Pharmacal Research - Insufficient efficacy of current single drug therapy of cancers have led to the advancement of combination drug-loaded formulations. Specifically, polymeric...     

Massively parallel sequencing analysis of nondegraded and degraded DNA mixtures using the ForenSeq™ system in combination with EuroForMix software

Massively parallel sequencing (MPS) technologies enable the simultaneous analysis of short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs). MPS also enables the detection of alleles of the minor contributors in imbalanced DNA mixtures. In this study, 59 STRs (amelogenin, 27 autosomal STRs, 7 X-STRs, and 24 Y-STRs) and 94 identity-informative SNPs of 119 unrelated Taiwanese (50 men, 69 women) were sequenced using a commercial MPS kit. Forty-eight nondegraded and 44 highly degraded two-person artificial DNA mixtures with various minor to major ratios (1:9, 1:19, 1:29, 1:39, 1:79, and 1:99) were analyzed to examine the performance of this system for detecting the alleles of the minor contributors in DNA mixtures. Likelihood ratios based on continuous model were calculated using the EuroForMix for DNA mixture interpretation. The STR and SNP genotypes of these 119 Taiwanese were obtained. Several sequence variants of STRs were observed. Using EuroForMix software based on the sequence data of autosomal STRs and autosomal SNPs, 97.9% (47/48) and 97.7% (42/43) of minor donors were accurately inferred among the successfully analyzed nondegraded and degraded DNA mixtures, respectively. In conclusion, combined with EuroForMix software, this commercial kit is effective for assignment of the minor contributors in nondegraded and degraded DNA mixtures.

     

Changes in ADC and T2-weighted MRI-derived radiomic features in patients treated with focal salvage HDR prostate brachytherapy for local recurrence after previous external-beam radiotherapy

PurposeTo explore the changes in T2-weighted (T2w) and apparent diffusion coefficient (ADC) magnetic resonance imaging -derived radiomic features of the gross tumor volume (GTV) from focal salvage high-dose-rate prostate brachytherapy (HDRB) and to correlate with clinical parameters.Materials and MethodsEligible patients included those with biopsy-confirmed local recurrence that correlated with MRI (T2w, ADC). Patients received 27 Gy in 2 fractions separated by 1 week to a quadrant consisting of the GTV. The MRI was repeated 1 year after HDRB. GTVs, planning target volumes, and normal prostate tissue control volumes were identified on the pre- and post-HDRB MRIs. Radiomic features from each GTV were extracted, and principle component analysis identified features with the highest variance.ResultsPre- and post-HDRB MRIs were obtained from 14 trial patients. Principle component analysis showed that 18 and 17 features contributed to 93% and 86% of the variance observed in the T2w and ADC data, respectively. Sixteen T2w features and 1 ADC GTV feature were different from the control volumes in the pre-HDRB images (p < 0.05). Ten T2w and 7 ADC GTV post-HDRB features were different from those of pre-HDRB (p < 0.05).ConclusionsExploratory analysis reveals several radiomic features in the T2w and ADC image GTVs that distinguish the GTV from healthy prostate tissue and change significantly after salvage HDRB.     

Cutaneous applied nano-ZnO reduce the ability of hair follicle stem cells to differentiate

The ability of metal oxide nanoparticles to penetrate the skin has aroused a great deal of interest during the past decade due to concerns over the safety of topically applied sunscreens that contain physical UV-resistant metal particles, such as nano-Zinc oxide (nZnO). Previous studies demonstrate that metal oxide nanoparticles accumulate in skin furrows and hair follicles following topical application while little is known about the consequence of these nanoparticles on skin homeostasis. The current investigation tested the effects of nZnO (0.5?mg/day mouse) on hair follicle physiology. Topical application of Vaseline containing nZnO, bulk ZnO (bZnO), or ionized Zn to newborn mice vibrissa pad over a period of 7 consecutive days revealed that nZnO accumulated within hair follicles, and this induced the apoptosis of hair follicle stem cells (HFSCs). In vitro studies also indicated that nZnO exposure caused obvious DNA damage and induced apoptosis in HFSCs. Furthermore, it was found that nZnO exposure perturbed genes associated with HFSC apoptosis, cell communication, and differentiation. HFSCs transplantation assay demonstrated that the potential of HFSCs to differentiate was reduced. This investigation indicates a potential risk of topically applied ZnO nanoparticles on skin homeostasis.