Peptide nanocarriers co-delivering an antisense oligonucleotide and photosensitizer elicit synergistic cytotoxicity.

Combination therapies demand co-delivery platforms with efficient entrapment of distinct payloads and specific delivery to cells and possibly organelles. Herein, we introduce the combination of two therapeutic modalities, gene and photodynamic therapy, in a purely peptidic platform. The simultaneous formation and cargo loading of the multi-micellar platform is governed by self-assembly at the nanoscale. The multi-micellar architecture of the nanocarrier and the positive charge of its constituent micelles offer controlled dual loading capacity with distinct locations for a hydrophobic photosensitizer (PS) and negatively charged antisense oligonucleotides (ASOs). Moreover, the nuclear localization signal (NLS) sequence built-in the peptide targets PS + ASO-loaded nanocarriers to the nucleus. Breast cancer cells treated with nanocarriers demonstrated photo-triggered enhancement of radical oxygen species (ROS) associated with increased cell death. Besides, delivery of ASO payloads resulted in up to 90 % knockdown of Bcl-2, an inhibitor of apoptosis that is overexpressed in more than half of all human cancers. Simultaneous delivery of PS and ASO elicited synergistic apoptosis to an extent that could not be reached by singly loaded nanocarriers or the free form of the drugs. Both, the distinct location of loaded compounds that prevents them from interfering with each other, and the highly efficient cellular delivery support the great potential of this versatile peptide platform in combination therapy.

Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data.

The Large Area Telescope on board the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10^{-3}. We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. The present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

Intrauterine administration of hCG immediately after oocyte retrieval and the outcome of ICSI: a randomized controlled trial.

STUDY QUESTION: Does the intrauterine administration of hCG immediately after oocyte retrieval in antagonist cycles with ICSI and fresh embryo transfer (ET) influence the implantation rate or chemical and clinical pregnancy rates? SUMMARY ANSWER: The intrauterine administration of hCG after oocyte retrieval increases the implantation rate and chemical and clinical pregnancy rates. WHAT IS KNOWN ALREADY: Over half of IVF/ICSI cycles fail due to implantation failure. Intrauterine administration of hCG, a few minutes before ET, increased the implantation and pregnancy rates in most but not in all studies. The effect of intrauterine administration of hCG, after oocyte retrieval, has not yet been studied. STUDY DESIGN, SIZE, DURATION: The study was a parallel, triple-blind randomized clinical trial (RCT) performed from September 2015 to February 2016, in a university hospital. We recruited women undergoing antagonist ovarian stimulation, ICSI and ET. For an effect size of 0.2, power of 80% at a significance level of 0.05, we needed 150 participants. Accounting for a 7% dropout rate, a total of 160 women was considered appropriate. A computer-generated randomization list with a block size of 4, with 1:1 allocation was used. The treatment allocation was placed in a sealed, opaque, envelope and picked up consecutively. Immediately after oocyte retrieval, patients in the intervention and control groups were treated with intrauterine injection of hCG and saline, respectively. Participants underwent ET on Day 3. A beta-hCG test was done at 2 weeks. If positive, three transvaginal-ultrasonographies (TVSs) were done at 3, 4 and 10 weeks after ET. The participants were called up thereafter and questioned about the continuity of their pregnancy. PARTICIPANTS/MATERIALS, SETTING, METHOD: Of 1990 women attending the infertility clinic of our university hospital, 508 were IVF/ICSI candidates during the study period, and 245 of the patients on an antagonist cycle met the criteria to be invited into our trial. Inclusion criteria were normal ovarian reserve, age ≤41, undergoing ICSI, and fresh ET and normal TSH and prolactin. Uncontrolled chronic disease, severe hydrosalpinx, severe endometriosis, morphologic embryo deficiencies, non-obstructive azospermia and high risk of severe ovarian hyperstimulation syndrome were criteria for exclusion. After taking an informed consent, a total of 158 participants were recruited, of which 80 were randomly allocated to receive intrauterine 500 IU hCG in up to 0.5 ml normal saline and 78 to receive intrauterine 0.5 ml normal saline immediately after oocyte retrieval, during general anaesthesia. ICSI was performed conventionally. The 4-8 cell embryos were transferred on the third day after oocyte retrieval. Implantation rate, chemical and clinical pregnancy rates were analysed and compared between the two groups. MAIN RESULTS AND THE ROLE OF CHANCE: Patients' demographic and baseline characteristics were comparable. The clinical results showed statistically significant differences between the two groups regarding the biochemical pregnancy rate (59.2 versus 31.3%; P = 0.001; odds ratio (OR) = 1.88; 95% CI, 1.26-2.82; risk difference (RD) = 27.8; 95% CI, 11.2-42.3), implantation rate (37 versus 17%; P = 0.012; OR = 2.29; 95% CI, 1.02-5.14; RD = 20.2; 95% CI, 5.4-33.8), clinical pregnancy rate (50.7 versus 16.4%; P < 0.001; OR = 3.08; 95% CI, 1.71-5.55; RD = 34.3; 95% CI, 18.7-47.6) and ongoing pregnancy rate (40.1 versus 13.4%; P = 0.001; OR = 3.04; 95% CI, 1.55-5.93; RD = 27.4; 95% CI, 12.7-40.6). The abortion and ectopic pregnancy rates were not statistically different between the two groups. LIMITATIONS, REASONS FOR CAUTION: The insertion of an intrauterine insemination catheter and the injection of a small amount of saline into the uterine cavity (without hCG) may also have some impact on implantation. This effect could be studied by comparing this intervention with another study group without any intrauterine injection.There are no specific side effects mentioned in the literature for the intrauterine administration of hCG, neither were any observed in our study, but it is best to be cautious about probable side effects, because this type of intervention is relatively new and experimental, and deserves more studies before being entered into routine clinical practice. WIDER IMPLICATIONS OF THE FINDINGS: Intrauterine administration of hCG immediately after oocyte pick up increases its effectiveness; however, further investigations are required before this procedure can be recommended for clinical practice. STUDY FUNDING/COMPETING INTERESTS: This study was supported by the Women's Health Research Center, Tabriz University of Medical Sciences, Iran. No external funds were used. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: IRCT201206165485N4. TRIAL REGISTRATION DATE: 2 September 2015. DATE OF FIRST PATIENT'S ENROLMENT: 2 September 2015.

Study of antimicrobial effects of vancomycin loaded PLGA nanoparticles against enterococcus clinical isolates.

Researchers have demonstrated that antimicrobial agents in nanoparticle (NP) forms have better activities. Vancomycin (VCM), as a glycopeptide antibiotic with antimicrobial activity against gram positive bacteria, is poorly absorbed from the intestinal tract. Enterococcus is a genus of bacteria that became resistant to a wide range of antibiotics in last decades, and cause severe infections in hospitalized patients. This paper describes preparation of VCM--loaded poly (lactic-co-glycolic acid) (PLGA) NPs and compares the antimicrobial effects with drug solution against clinical Enterococcus isolates. VCM-loaded PLGA NPs were fabricated by W1/O/W2 solvent evaporation method. The comparison of obtained Minimum Inhibitory Concentration (MIC) values showed a significant decrease in the antimicrobial effect of VCM -loaded NPs. Results also indicated that the potency of the NPs against VCM resistant isolates of Enterococcus was less than VCM susceptible isolates. The reduced antimicrobial effect of formulated NPs in invitro condition is perhaps related to the strong electrostatic linkage between hydrophilic drug (VCM) and hydrophobic polymer (PLGA) that lead to the slow release of the antibiotic from polymeric NPs.

Human retinal cadmium accumulation as a factor in the etiology of age-related macular degeneration.

Cadmium is a naturally occurring, highly toxic, metallic element. It pollutes the environment as a result of industrial activity and accumulates in human tissues with a long biological half-life. Cadmium content has been demonstrated to increase in human retinal tissues as a function of age and tobacco smokers have approximately twice as much cadmium in retinal tissues than non-smokers. Smoking is also a key environmental risk factor for the retinal disease age-related macular degeneration (AMD). Recent studies have shown that urinary cadmium levels (a measure of Cd body burden) are higher in smokers who have AMD. We now report the Cd measurements in human retinal tissues from eyes afflicted with AMD compared to non-diseased eyes (controls) from age-matched donors. Human donor eyes frozen under argon gas were assessed for AMD severity using color stereoscopic fundus photographs and the Minnesota Grading System. Cadmium, zinc and, copper levels were measured in retinal tissues (neural retina, retinal pigment epithelium and choroid) using inductively coupled plasma mass spectrometry and graphite furnace spectrophotometry and values were normalized to tissue protein levels. Higher Cd levels were found in the neural retina and RPE for eyes afflicted with AMD compared to controls in males, differences were not statistically significant in females. The results indicate that higher retinal cadmium burdens are associated with the presence of AMD at least in males and suggest possible gender differences in the metabolism of metals in the human retina.

Steric restrictions on the binding of large metal ions to serum transferrin.

Apotransferrin in 0.1 M N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid at 25 degrees C and pH 7.4 was titrated with acidic solutions of Lu3+, Tb3+, and Eu3+. Metal binding at the two specific metal-binding sites of transferrin was followed from changes in the difference UV spectra at 245 nm. The binding of Tb3+ was also followed from changes in the fluorescence emission spectrum at 549 nm. Apotransferrin was titrated with solutions containing varying ratios of the metal ion and the competitive chelating agent nitrilotriacetic acid, and metal-transferrin binding constants were calculated by nonlinear least-squares fits of the absorbance as a function of titrant added. The sequential carbonate-independent equilibrium constants for the binding of two metal ions are log KM1 = 11.08 and log KM2 = 7.93 for Lu3+, log KM1 = 11.20 and log KM2 = 7.61 for Tb3+, and log KM1 = 9.66 and log KM2 = 7.27 for Eu3+. Titrations of both C-terminal and N-terminal monoferric transferrins indicate that all of these metal ions bind more strongly to the C-terminal binding site. The trend in log K values as a function of the lanthanide ionic radius has been evaluated both by plots of log K versus the metal ion charge/radius ratio and by linear free-energy relationships in which binding constants for complexes of the larger lanthanides are plotted versus the binding constants for complexes with the smallest lanthanide, Lu3+. Both methods indicate that there is a sharp drop in the binding constants for the C-terminal binding site for metals larger than Tb3+. This decrease is attributed to a steric hindrance to the binding of the larger cations. The steric effect is not as strong for metal binding at the N-terminal site. As a result, the selectivity for binding to the C-terminal site, which is quite high for the smaller lanthanides, drops sharply on going from Tb3+ to Nd3+.

Binding of monovalent anions to human serum transferrin.

Serum transferrin is the protein whose primary function is to bind iron and transport it through the blood. Apotransferrin has two specific metal-binding sites that bind a variety of metal ions in addition to the ferric ion. The distinguishing feature of the transferrins is that a "synergistic" bicarbonate anion is bound along with the metal ion to form a stable Fe(3+)-CO3-Tf ternary complex. Previous research has shown that apotransferrin will also bind divalent anions such as phosphate and sulfate. Difference UV spectroscopy has now been used to show that a series of monovalent anions bind weakly to apotransferrin. Equilibrium constants for the binding of chloride, perchlorate, bromide, fluoride and Hepes have been calculated. A reaction scheme for the binding of anions is proposed which predicts that the binding of the nonsynergistic anions to apotransferrin will interfere with metal binding by competing directly with the binding of the synergistic bicarbonate anion. Difference UV data are presented which demonstrate this type of competition between nonsynergistic anions and Tb3+. Competition from the nonsynergistic anions follows the order HPO4(2-) > SO4(2-) approximately F- > ClO4- approximately Cl- approximately Br-. Speciation calculations have been performed to determine the concentrations of anion-apotransferrin complexes in Hepes and Tris buffers and in human serum and to estimate the extent to which competition from anions in the buffer will interfere with metal-binding to apotransferrin.