Are Randomized Trials Better? Comparison of Baseline Covariate Balance of a Propensity Score-Balanced Lumbar Spine IDE Trial and Comparable RCTs.

Study Design: Prospective Observational Propensity Score.

Objectives: Randomization may lead to bias when the treatment is unblinded and there is a strong patient preference for treatment arms (such as in spinal device trials). This report describes the rationale and methods utilized to develop a propensity score (PS) model for an investigational device exemption (IDE) trial (NCT03115983) to evaluate decompression and stabilization with an investigational dynamic sagittal tether (DST) vs decompression and Transforaminal Lumbar Interbody Fusion (TLIF) for patients with symptomatic grade I lumbar degenerative spondylolisthesis with spinal stenosis.

Investigating the Formation of Polymer-Nanoparticle Complex Coacervate Hydrogels Using Polymerization-Induced Self-Assembly-Derived Nanogels with a Succinate-Functional Core.

This paper reports polymer-nanoparticle-based complex coacervate (PNCC) hydrogels prepared by mixing anionic nanogels synthesized by polymerization-induced self-assembly (PISA) and cationic branched poly(ethylenimine) (bPEI). Specifically, poly(3-sulfopropyl methacrylate)--poly(2-(methacryloyloxy)ethyl succinate) (PKSPMA-PMES) nanogels were prepared by reversible addition-fragmentation chain-transfer (RAFT)-mediated PISA. These nanogels swell on increasing the solution pH and form free-standing hydrogels at 20% w/w and pH ≥ 7.

Pyrene-functionalized poly(methacrylic acid) acts as an efficient stabilizer for graphene nanoplatelets and facilitates their use in waterborne latex formulations.

Hypothesis: Pyrene derivatives are effective motifs when designing graphene-philic surfactants, enabling the use of hydrophobic graphene-based nanomaterials in waterborne formulations. Hence, novel pyrene end-functionalized polymeric stabilizers show promise for stabilizing aqueous graphene nanomaterial dispersions, and offer benefits over traditional small molecule surfactants.

Experiments: Pyrene end-functionalized poly(methacrylic acid) (Py-PMAA, where n = 68 to 128) was synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization of MAA using a pyrene-containing RAFT chain-transfer agent.

pH-Responsive Nanogels Generated by Polymerization-Induced Self-Assembly of a Succinate-Functional Monomer.

Colloidal nanogels formed from a pH-responsive poly(succinate)-functional core and a poly(sulfonate)-functional corona were prepared via a previously unreported reversible addition-fragmentation chain-transfer (RAFT)-mediated aqueous emulsion polymerization-induced self-assembly (PISA) route. Specifically, a poly(potassium 3-sulfopropyl methacrylate) (PKSPMA) macromolecular chain-transfer agent (macro-CTA) was synthesized via RAFT solution polymerization followed by chain-extension with a hydrophobic, carboxylic acid-functional, 2-(methacryloyloxy) ethyl succinate (MES) monomer at pH 2. Colloidal nanoparticles with tunable diameters between 66 to 150 nm, depending on the core composition, and narrow particle size distributions were obtained at 20% w/w solids.

Multifunctional Self-Assembled Block Copolymer/Iron Oxide Nanocomposite Hydrogels Formed from Wormlike Micelles.

This article reports the preparation of multifunctional magnetic nanocomposite hydrogels formed from wormlike micelles. Specifically, iron oxide nanoparticles were incorporated into a temperature responsive block copolymer, poly(glycerol monomethacrylate)--poly(2-hydroxypropyl methacrylate) (PGMA--PHPMA), and graphene oxide (GO) dispersion at a low temperature (∼2 °C) through high-speed mixing and returning the mixture to room temperature, resulting in the formation of nanocomposite gels. The optimal concentrations of iron oxide and GO enhanced the gel strength of the nanocomposite gels, which exhibited a strong magnetic response when a magnetic field was applied.