Predicting DNA toehold-mediated strand displacement rate constants using a DNA-BERT transformer deep learning model.

Dynamic DNA nanotechnology is driving exciting developments in molecular computing, cargo delivery, sensing and detection. Combining this innovative area of research with the progress made in machine learning will aid in the design of sophisticated DNA machinery. Herein, we present a novel framework based on a transformer architecture and a deep learning model which can predict the rate constant of toehold-mediated strand displacement, the underlying process in dynamic DNA nanotechnology.

Immuno-Modulatory Effects of Microparticles Formulated from Degradable Polystyrene Analogue.

Environmental accumulation of non-degradable polystyrene (PS) microparticles from plastic waste poses potential adverse impact on marine life and human health. Herein, microparticles from a degradable PS analogue (dePS) are formulated and their immuno-modulatory characteristics are comprehensively evaluated. Both dePS copolymer and microparticles are chemically degradable under accelerated hydrolytic condition.

Backbone degradable poly(acrylic acid) analogue via radical ring-opening copolymerization and enhanced biodegradability.

Degradable poly(acrylic acid) has been prepared via free radical ring-opening copolymerization of tert-butyl acrylate and 2-methylene-1,3-dioxepane followed by tert-butyl deprotection, under acidic conditions. The resulting degradable poly(acrylic acid) analogue possesses ester groups within the backbone, which facilitate environmental hydrolysis into short chain oligomers, which subsequently undergo biodegradation. The degradable poly(acrylic acid) reported displays a significant degree of biodegradability (27.

A general strategy for degradable single-chain nanoparticles via cross-linker mediated chain collapse of radical copolymers.

Radical ring-opening copolymerization (rROP) between 2-methylene-1,3-dioxepane (MDO) and methacrylic acid N-hydroxysuccinimide ester (NHSMA) furnishes a reactive polyester-based linear copolymer precursor. Subsequent cross-linker mediated chain collapse affords degradable single-chain nanoparticles (DSCNPs). This methodology is an experimentally robust and straightforward route to main-chain degradable polymeric nanoparticles in the sub-30 nm size range.

Perylene Diimide Nanoprobes for In Vivo Tracking of Mesenchymal Stromal Cells Using Photoacoustic Imaging.

Noninvasive bioimaging techniques are critical for assessing the biodistribution of cellular therapies longitudinally. Among them, photoacoustic imaging (PAI) can generate high-resolution images with a tissue penetration depth of ∼4 cm. However, it is essential and still highly challenging to develop stable and efficient near-infrared (NIR) probes with low toxicity for PAI.

Unraveling the History and Revisiting the Synthesis of Degradable Polystyrene Analogues via Radical Ring-Opening Copolymerization with Cyclic Ketene Acetals.

Degradable analogues of polystyrene are synthesized via radical ring-opening (co)polymerization (rROP) between styrene and two cyclic ketene acetals, namely 2-methylene-1,3-dioxepane (MDO) and 5,6-benzo-2-methylene-1,3-dioxepane (BMDO). This approach periodically inserts ester bonds throughout the main chain of polystyrene, imparting a degradation pathway via ester hydrolysis. We discuss the historical record of this approach, with careful attention paid to the conflicting findings previously reported.

A Roadmap towards Successful Nanocapsule Synthesis via Vesicle Templated RAFT-Based Emulsion Polymerization.

Vesicle templated emulsion polymerization is a special form of emulsion polymerization where the polymer is grown from the outside of the vesicle, leading to nanocapsules. Cost effective nanocapsules synthesis is in high demand due to phasing out of older methods for capsule synthesis. Although the first indications of this route being successful were published some 10 years ago, until now a thorough understanding of the parameters controlling the morphologies resulting from the template emulsion polymerization was lacking.

Formation of hydrophobic drug nanoparticles via ambient solvent evaporation facilitated by branched diblock copolymers.

Hydrophobic drug nanoparticles have been prepared by ambient solvent evaporation from ethanol at room temperature. Poly(ethylene glycol)-b-(N-isopropylacrylamide) (PEG-b-PNIPAm) branched diblock copolymers are employed to prevent drug crystallization during solvent evaporation and to stabilize the drug nanoparticles once suspended in aqueous media. After the initial solvent evaporation the dry materials obtained exhibit excellent stability during storage and can be readily dissolved in water to produce aqueous drug nanoparticles suspensions.

Unimolecular branched block copolymer nanoparticles in methanol for the preparation of poorly water-soluble drug nanoparticles.

Spherical unimolecular amphiphilic branched A-B block copolymer nanoparticles in methanol are fabricated via thermal annealing using the methanolic upper critical solution temperature (UCST) of the hydrophobic block segment. These polymer nanoparticles are then used to produce an aqueous poorly water-soluble drug nanoparticle suspension with a mass : drug ratio of 1 : 1 and 100% nanoparticle yield. The drug nanoparticles in the suspension are stabilized by multiple polymer nanoparticles.

Octreotide Functionalized Nano-Contrast Agent for Targeted Magnetic Resonance Imaging.

Reversible addition-fragmentation chain transfer (RAFT) polymerization has been employed to synthesize branched block copolymer nanoparticles possessing 1,4,7,10-tetraazacyclododecane-N,N,'N,″N,‴-tetraacetic acid (DO3A) macrocycles within their cores and octreotide (somatostatin mimic) cyclic peptides at their periphery. These polymeric nanoparticles have been chelated with Gd and applied as magnetic resonance imaging (MRI) nanocontrast agents. This nanoparticle system has an r relaxivity of 8.

Nanoformulation and encapsulation approaches for poorly water-soluble drug nanoparticles.

During the last few decades the nanomedicine sector has emerged as a feasible and effective solution to the problems faced by the high percentage of poorly water-soluble drugs. Decreasing the size of such drug compounds to the nanoscale can significantly change their physical properties, which lays the foundation for the use of nanomedicine for pharmaceutical applications. Various techniques have been developed to produce poorly water-soluble drug nanoparticles, mainly to address the poor water-soluble issues but also for the efficient and targeted delivery of such drugs.

Drug nanoparticles by emulsion-freeze-drying via the employment of branched block copolymer nanoparticles.

A large percentage of drug compounds exhibit low water solubility and hence low bioavailability and therapeutic efficacy. This may be addressed by preparation of drug nanoparticles, leading to enhanced dissolution rate and direct use for treatment. Various methods have been developed to produce drug nanocrystals, including wet milling, homogenization, solution precipitation, emulsion diffusion, and the recently developed emulsion freeze-drying.

Synthesis and in vivo magnetic resonance imaging evaluation of biocompatible branched copolymer nanocontrast agents.

Branched copolymer nanoparticles (D(h) =20-35 nm) possessing 1,4,7, 10-tetraazacyclododecane-N,N',N″,N‴-tetraacetic acid macrocycles within their cores have been synthesized and applied as magnetic resonance imaging (MRI) nanosized contrast agents in vivo. These nanoparticles have been generated from novel functional monomers via reversible addition-fragmentation chain transfer polymerization. The process is very robust and synthetically straightforward.

Templating a polymer-scaffolded dynamic combinatorial library.

A water soluble polymer-scaffolded dynamic combinatorial library whose members can interconvert through acylhydrazone exchange was prepared and shown to re-equilibrate in the presence of macromolecular templates.

pH triggered self-assembly of core cross-linked star polymers possessing thermoresponsive cores.

Core cross-linked star polymers possessing responsiveness to pH and temperature stimuli have been prepared, and we demonstrate how changes to pH and temperature can be used to trigger the release and uptake of a hydrophobic dye.

Reactive thermoresponsive copolymer scaffolds.

Thermoresponsive copolymer scaffolds containing reactive aldehyde functions were prepared and a selection of organic residues conjugated to these copolymer scaffolds through oxime/hydrazone formation. The conjugation of hydrophobic residues affords copolymers whose lower solution critical temperatures are in most cases higher than that of the parent copolymer scaffold.

The formation of core cross-linked star polymers containing cores cross-linked by dynamic covalent imine bonds.

Diblock copolymers possessing amino or aldehyde functions within one of their blocks were prepared using RAFT polymerization techniques. These polymers were shown to cross-link through dynamic imine bonds to form core cross-linked star polymers which display a size-dependency upon the concentration at which the cross-linking reactions are performed.