Polymer-nucleobase composites for chemotherapy drug capture.

Intravenous chemotherapy (, doxorubicin (DOX)) is standard treatment for many cancers but also leads to side effects due to off-target toxicity. To address this challenge, devices for removing off-target chemotherapy agents from the bloodstream have been developed, but the efficacy of such devices relies on the ability of the underlying materials to specifically sequester small-molecule drugs. Anion-exchange materials, genomic DNA, and DNA-functionalized iron oxide particles have all been explored as drug-capture materials, but cost, specificity, batch-to-batch variation, and immunogenicity concerns persist as challenges.

Enzyme-Triggered Chemodynamic Therapy via a Peptide-H S Donor Conjugate with Complexed Fe.

Inducing high levels of reactive oxygen species (ROS) inside tumor cells is a cancer therapy method termed chemodynamic therapy (CDT). Relying on delivery of Fenton reaction promoters such as Fe , CDT takes advantage of overproduced ROS in the tumor microenvironment. We developed a peptide-H S donor conjugate, complexed with Fe , termed AAN-PTC-Fe .

Characterizing Ion-Polymer Interactions in Aqueous Environment with Electric Fields.

Polymers make the basis of highly tunable materials that could be designed and optimized for metal recovery from aqueous environments. While experimental studies show that this approach has potential, it suffers from a limited knowledge of the detailed molecular interaction between polymers and target metal ions. Here, we propose to calculate intrinsic electric fields from polarizable force field molecular dynamics simulations to characterize the driving force behind Eu motion in the presence of poly(ethylenimine methylenephosphonate), a specifically designed metal chelating polymer.

Exploring the role of polymer hydrophobicity in polymer-metal binding thermodynamics.

Metal-chelating polymers play a key role in rare-earth element (REE) extraction and separation processes. Often, these processes occur in aqueous solution, but the interactions among water, polymer, and REE are largely under-investigated in these applications. To probe these interactions, we synthesized a series of poly(amino acid acrylamide)s with systematically varied hydrophobicity around a consistent chelating group (carboxylate).

Biodegradable Poly(Lactic Acid) Nanocomposites for Fused Deposition Modeling 3D Printing.

3D printing by fused deposition modelling (FDM) enables rapid prototyping and fabrication of parts with complex geometries. Unfortunately, most materials suitable for FDM 3D printing are non-degradable, petroleum-based polymers. The current ecological crisis caused by plastic waste has produced great interest in biodegradable materials for many applications, including 3D printing.

Effect of Copolymer Structure on Rare-Earth-Element Chelation Thermodynamics.

Rare-earth elements (REEs) are crucial to modern technology, leading to a high demand for materials capable of REE extraction and purification. Metal-chelating polymers (e.g.

Isothermal titration calorimetry: practical approaches and current applications in soft matter.

Isothermal Titration Calorimetry (ITC) elucidates the thermodynamic profile (ΔH, ΔS, ΔG, Ka, and stoichiometry) of binding and dissociation reactions in solution. While ITC has primarily been used to investigate the thermodynamics of interactions between biological macromolecules and small molecules, it has become increasingly common for measuring binding interactions between synthetic polymers and small molecules, ions, or nanoparticles. This tutorial review describes applications of ITC in studying synthetic macromolecules and provides experimental guidelines for performing ITC experiments.

Bulk and surface structural changes in high nickel cathodes subjected to fast charging conditions.

A layered oxide cathode, LiNi0.6Mn0.2Co0.

Drug capture materials based on genomic DNA-functionalized magnetic nanoparticles.

Chemotherapy agents are notorious for producing severe side-effects. One approach to mitigating this off-target damage is to deliver the chemotherapy directly to a tumor via transarterial infusion, or similar procedures, and then sequestering any chemotherapeutic in the veins draining the target organ before it enters the systemic circulation. Materials capable of such drug capture are yet to be fully realized.

Functionalized 3D Architected Materials via Thiol-Michael Addition and Two-Photon Lithography.

Fabrication of functionalized 3D architected materials is achieved by a facile method using functionalized acrylates synthesized via thiol-Michael addition, which are then polymerized using two-photon lithography. A wide variety of functional groups can be attached, from Boc-protected amines to fluoroalkanes. Modification of surface wetting properties and conjugation with fluorescent tags are demonstrated to highlight the potential applications of this technique.

Application of Ionic Liquids in Pot-in-Pot Reactions.

Pot-in-pot reactions are designed such that two reaction media (solvents, catalysts and reagents) are isolated from each other by a polymeric membrane similar to matryoshka dolls (Russian nesting dolls). The first reaction is allowed to progress to completion before triggering the second reaction in which all necessary solvents, reactants, or catalysts are placed except for the starting reagent for the target reaction. With the appropriate trigger, in most cases unidirectional flux, the product of the first reaction is introduced to the second medium allowing a second transformation in the same glass reaction pot--albeit separated by a polymeric membrane.

Aminobisphosphonate Polymers via RAFT and a Multicomponent Kabachnik-Fields Reaction.

Polyacrylamides containing pendant aminobisphosphonate groups are synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization and a multicomponent postpolymerization functionalization reaction. A Moedritzer-Irani reaction installs the phosphonic acid groups on well-defined, RAFT-generated polymers bearing a pendant amine. An alternate route to the same materials is developed utilizing a three-component Kabachnik-Fields reaction and subsequent dealkylation.

Synthesis of polymeric phosphonates for selective delivery of radionuclides to osteosarcoma.

Discussed in detail is the synthesis and primary structure characterization of two polymers aimed at advancing the treatment of pediatric osteosarcoma. These polymers are designed to systemically deliver radiometals specifically to osteosarcomas using the passive targeting mechanism of enhanced permeability and retention (the EPR effect). The approach begins with the synthesis of a polymer capable of binding radiometals, for which prior data show improved site-specific targeting of solid tumors.

Replacing -CH2CH2- with -CONH- does not significantly change rates of charge transport through Ag(TS)-SAM//Ga2O3/EGaIn junctions.

This paper describes physical-organic studies of charge transport by tunneling through self-assembled monolayers (SAMs), based on systematic variations of the structure of the molecules constituting the SAM. Replacing a -CH(2)CH(2)- group with a -CONH- group changes the dipole moment and polarizability of a portion of the molecule and has, in principle, the potential to change the rate of charge transport through the SAM. In practice, this substitution produces no significant change in the rate of charge transport across junctions of the structure Ag(TS)-S(CH(2))(m)X(CH(2))(n)H//Ga(2)O(3)/EGaIn (TS = template stripped, X = -CH(2)CH(2)- or -CONH-, and EGaIn = eutectic alloy of gallium and indium).

Solvent Effects in Alternating ADMET Polymerization.

Alternating AB copolymers were synthesized by exploiting the selectivity of the metathesis reaction between α,ω-dienes and α,ω-diacrylates. Unlike standard acyclic diene metathesis (ADMET) polymerizations, the copolymerization of dienes and diacrylates does not require high vacuum conditions. This work utilizes this unique characteristic to explore the effect of various solvents on ADMET polymerization.

Odd-even effects in charge transport across self-assembled monolayers.

This paper compares charge transport across self-assembled monolayers (SAMs) of n-alkanethiols containing odd and even numbers of methylenes. Ultraflat template-stripped silver (Ag(TS)) surfaces support the SAMs, while top electrodes of eutectic gallium-indium (EGaIn) contact the SAMs to form metal/SAM//oxide/EGaIn junctions. The EGaIn spontaneously reacts with ambient oxygen to form a thin (∼1 nm) oxide layer.

Sequential reactions with Grubbs catalyst and AD-mix-alpha/beta using PDMS thimbles.

Incompatible Grubbs catalyst and an osmium dihydroxylation catalyst were site-isolated from each other using polydimethylsiloxane thimbles. The Grubbs catalyst was added to the interior of the thimbles, and AD-mix-alpha/beta was added to the exterior. Organic substrates readily fluxed through the walls of the thimbles and reacted with each catalyst.

A materials approach to site-isolation of Grubbs catalysts from incompatible solvents and m-chloroperoxybenzoic acid.

The development of a method for site-isolation of Grubbs second-generation catalyst from MCPBA is described. In these reactions, Grubbs catalyst was dissolved in a solvent consisting of a mixture (1:1 v/v) of 1-butyl-3-methylimidazolium hexafluorophosphate and methylene chloride and completely encapsulated within a thimble fabricated from polydimethylsiloxane (PDMS). A series of molecules that react by cross metathesis or ring-closing metathesis were added to the interior of the thimble and allowed to react.