Early and extended erythropoietin monotherapy after hypoxic ischaemic encephalopathy:a multicentre double-blind pilot randomised controlled trial

Objective: To examine the feasibility of early and extended erythropoietin monotherapy after hypoxic ischaemic encephalopathy (HIE). Design: Double-blind pilot randomised controlled trial.Setting: Eight neonatal units in South Asia. Patients: Neonates (≥36 weeks) with moderate or severe HIE admitted between 31 December 2022 and 3 May 2023. Interventions: Erythropoietin (500 U/kg daily) or to the placebo (sham injections using a screen) within 6 hours of birth and continued for 9 days. MRI at 2 weeks of age. Main outcomes and measures: Feasibility of randomisation, drug administration and assessment of brain injury using MRI. Results: Of the 154 neonates screened, 56 were eligible; 6 declined consent and 50 were recruited; 43 (86%) were inborn. Mean (SD) age at first dose was 4.4 (1.2) hours in erythropoietin and 4.1 (1.0) hours in placebo. Overall mortality at hospital discharge occurred in 5 (19%) vs 11 (46%) (p=0.06), and 3 (13%) vs 9 (40.9%) (p=0.04) among those with moderate encephalopathy in the erythropoietin and placebo groups. Moderate or severe injury to basal ganglia, white matter and cortex occurred in 5 (25%) vs 5 (38.5%); 14 (70%) vs 11 (85%); and 6 (30%) vs 2 (15.4%) in the erythropoietin and placebo group, respectively. Sinus venous thrombosis was seen in two (10%) neonates in the erythropoietin group and none in the control group. Conclusions: Brain injury and mortality after moderate or severe HIE are high in South Asia. Evaluation of erythropoietin monotherapy using MRI to examine treatment effects is feasible in these settings. Trial registration number: NCT05395195

Polymeric nanoparticles synthesized via miniemulsion process as templates for biomimetic mineralization

In this work, polymeric nanoparticles synthesized via the miniemulsion process are employed as templates for the biomimetic mineralization of hydroxyapatite (the thermodynamically stable form of calcium phosphate) in the aqueous phase. As the versatile miniemulsion technique allows the fabrication of polymeric nanoparticles by the polymerization of respective monomers as well as by using the preformed polymers, the technique was exploited to produce nanoparticles from natural as well as synthetic polymers. While gelatin (a natural polymer) and aliphatic polyesters (synthetic biodegradable polymers) were used as preformed polymers, a copolymer comprising of poly(styrene-co-acrylic acid) was used as a biocompatible polymer for the formulation of nanoparticles. These formulated polymer nanoparticles were subsequently used as templates for the calcium phosphate mineralization in aqueous phase. As the gelatin nanoparticles by themselves have high potential to be used in the pharmaceutical field, the first part of the work deals with the synthesis and optimization of the gelatin nanoparticles using the miniemulsion process. The optimized stable nanoparticles were further used as templates for biomimetic mineralization of calcium phosphate in the second part. While gelatin nanoparticles were used as confined nano-environment to perform crystallization inside the particles, in the third part of the work, the surface-functionalized polymeric nanoparticles (poly(styrene-co-acrylic acid)) were exploited as templates to perform crystallization outside on the surface of the particles. In the fourth part, the polyester based nanoparticles comprising of the anionic functional groups distributed in the nanoparticle matrix were used as templates for calcium phosphate mineralization. The hybrid nanoparticles were characterized using TEM, HRSEM, and XRD. All these composite nanoparticles have high potential for tissue engineering applications

Conjugated Polymer Nanoparticles for Bioimaging

During the last decade, conjugated polymers have emerged as an interesting class of fluorescence imaging probes since they generally show high fluorescence brightness, high photostability, fast emission rates, non-blinking behavior and low cytotoxicity. The main concern related to most conjugated polymers is their lack of hydrophilicity and thereby poor bio-availability. This can, however, be overcome by the formulation of conjugated polymer nanoparticles in aqueous medium. This review provides an overview of the different techniques employed for the preparation of conjugated polymer nanoparticles, together with methods to improve their photoluminescence quantum yields. For selective targeting of specific cells, dedicated surface functionalization protocols have been developed, using different functional groups for ligand immobilization. Finally, conjugated polymer nanoparticles have recently also been employed for theranostic applications, wherein the particles are simultaneously used as fluorescent probes and carriers for anti-tumor drugs

Assessing the toxicity of Pb- and Sn-based perovskite solar cells in model organism Danio rerio

Intensive development of organometal halide perovskite solar cells has lead to a dramatic surge in power conversion efficiency up to 20%. Unfortunately, the most efficient perovskite solar cells all contain lead (Pb), which is an unsettling flaw that leads to severe environmental concerns and is therefore a stumbling block envisioning their large-scale application. Aiming for the retention of favorable electro-optical properties, tin (Sn) has been considered the most likely substitute. Preliminary studies have however shown that Sn-based perovskites are highly unstable and, moreover, Sn is also enlisted as a harmful chemical, with similar concerns regarding environment and health. To bring more clarity into the appropriateness of both metals in perovskite solar cells, we provide a case study with systematic comparison regarding the environmental impact of Pb- and Sn-based perovskites, using zebrafish (Danio Rerio) as model organism. Uncovering an unexpected route of intoxication in the form of acidification, it is shown that Sn based perovskite may not be the ideal Pb surrogate

Photoinduced Sequence-Controlled Copper-Mediated Polymerization: Synthesis of Decablock Copolymers

Photoinitiated copper-mediated radical polymerization offers an one-pot and time efficient method of preparing a decablock copolymer PMA-PtBA-PMA-PDEGA-PMA-PtBA-PMA-PDEGA-PnBA-PDEGA with an overall molecular weight of 8500 g·mol^–1. The molecular weight is in close agreement with theoretical expectations and significantly narrow dispersities (<i>Đ</i> = 1.1–1.17) are achieved for the various block extensions. The <i>tert</i>-butyl group of the decadeblock was deprotected to form PMA-PAA-PMA-PDEGA-PMA-PAA-PMA-PDEGA-PnBA-PDEGA. The deprotection is confirmed by the disappearance of <i>tert</i>-butyl signal and the loss of molecular weight investigated by ¹H NMR and SEC, respectively. The carboxylic group of PAA is protonated in acidic solution (water insoluble) and deprotonated in basic solution (water-soluble). This enables a conformational change of PMA-PAA-PMA-PDEGA-PMA-PAA-PMA-PDEGA-PnBA-PDEGA in water/ethanol mixture (80/20%v/v), as is demonstrated by a turbid solution at pH 2 and transparent solutions at pH 10

Ionic strength dependent vesicle adsorption and phase behavior of anionic phospholipids on a gold substrate

The authors report on the effect of ionic strength on the formation of supported vesicle layers of anionic phospholipids 1,2-dimyristoyl-sn-glycero-3-phospho-rac-glycerol (DMPG) and dimyristoylphosphatidylserine (DMPS) onto gold. Using quartz crystal microbalance with dissipation monitoring the authors show that vesicle adsorption is mainly governed by NaCl concentration, reflecting the importance of electrostatic interactions in anionic lipids, as compared to zwitterionic 1,2-dimyristoyl-sn-glycero-3-phosphocholine. At low ionic strength, low or no adsorption is observed as a result of vesicle–vesicle electrostatic repulsion. At medium ionic strength, the negative charges of DMPG and DMPS are screened resulting in larger adsorption and a highly dissipative intact vesicle layer. In addition, DMPS exhibits a peculiar behavior at high ionic strength that depends on the temperature of the process.info:eu-repo/semantics/publishe

Ultrafast Self-Assembly Using Ultrasound: A Facile Route to the Rapid Fabrication of Well-Ordered Dense Arrays of Inorganic Nanostructures

A rapid and facile route allows the self-assembly of precursor micelles loaded with metal salts on an unprecedented short timescale. Micellar arrays can then be transformed into high-quality (metal or metal oxide) nanoparticle arrays. This promising route offers functionalization of surfaces by nanomaterials on industrially relevant timescales. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.status: publishe