Photo-Cross-linked Gelatin Methacryloyl Hydrogels Enable the Growth of Primary Human Endometrial Stromal Cells and Epithelial Gland Organoids.

three-dimensional (3D) models are better able to replicate the complexity of real organs and tissues than 2D monolayer models. The human endometrium, the inner lining of the uterus, undergoes complex changes during the menstrual cycle and pregnancy. These changes occur in response to steroid hormone fluctuations and elicit crosstalk between the epithelial and stromal cell compartments, and dysregulations are associated with a variety of pregnancy disorders.

Erratum: Effect of transdermal drug delivery patches on the stratum corneum: in vivo inspection with a handheld terahertz probe: publisher's note.

[This corrects the article on p. 3064 in vol. 15, PMID: 38855675.

Thermoreversible [2 + 2] Photodimers of Monothiomaleimides and Intrinsically Recyclable Covalent Networks Thereof.

The development of intrinsically recyclable cross-linked materials remains challenged by the inherently unfavorable chemical equilibrium that dictates the efficiency of the reversible covalent bonding/debonding chemistry. Rather than having to (externally) manipulate the bonding equilibrium, we here introduce a new reversible chemistry platform based on monosubstituted thiomaleimides that can undergo complete and independent light-activated covalent bonding and on-demand thermal debonding above 120 °C. Specifically, repeated bonding/debonding of a small-molecule thiomaleimide [2 + 2] photodimer is demonstrated over five heat/light cycles with full conversion in both directions, thereby regenerating its initial monothiomaleimide constituents.

Effect of transdermal drug delivery patches on the stratum corneum: inspection with a handheld terahertz probe.

Transdermal drug delivery patches are a good alternative to hypodermic drug injection. The drug delivery efficiency depends strongly on the hydration of the skin under treatment, and therefore, it is essential to study the effects on the skin induced by the application of these medical-grade patches. Terahertz (THz) spectroscopy shows great promise for non-invasive skin evaluation due to its high sensitivity to subtle changes in water content, low power and non-ionizing properties.

Synthesis and Characterization of High Glycolic Acid Content Poly(glycolic acid--butylene adipate--butylene terephthalate) and Poly(glycolic acid--butylene succinate) Copolymers with Improved Elasticity.

Poly(glycolic acid) (PGA) is a biodegradable polymer with high gas barrier properties, mechanical strength, and heat deflection temperature. However, PGA's brittleness severely limits its application in packaging, creating a need to develop PGA-based copolymers with improved elasticity that maintain its barrier properties and hydrolytic degradability. In this work, a series of PGBAT (poly(glycolic acid--butylene) adipate--butylene terephthalate) copolymers containing 21-92% glycolic acid () with values of 46,700-50,600 g mol were synthesized via melt polycondensation, and the effects of altering the on PGBAT's thermomechanical properties and hydrolysis rate were investigated.

Influence of the Topology of Poly(L-Cysteine) on the Self-Assembly, Encapsulation and Release Profile of Doxorubicin on Dual-Responsive Hybrid Polypeptides.

Τhe synthesis of a series of novel hybrid block copolypeptides based on poly(ethylene oxide) (PEO), poly(l-histidine) (PHis) and poly(l-cysteine) (PCys) is presented. The synthesis of the terpolymers was achieved through a ring-opening polymerization (ROP) of the corresponding protected -carboxy anhydrides of --l-histidine and --butyl-l-cysteine, using an end-amine-functionalized poly(ethylene oxide) (PEO-NH) as macroinitiator, followed by the deprotection of the polypeptidic blocks. The topology of PCys was either the middle block, the end block or was randomly distributed along the PHis chain.

Photocrosslinking of Polyacrylamides Using [2 + 2] Photodimerisation of Monothiomaleimides.

The [2 + 2] photocycloaddition of monothiomaleimides (MTMs) has been exploited for the photocrosslinking of polyacrylamides. Polymer scaffolds composed of dimethylacrylamide and varying amounts of d,l-homocysteine thiolactone acrylamide (5, 10, and 20 mol %) were synthesized via free-radical polymerization, whereby the latent thiol functionality was exploited to incorporate MTM motifs. Subsequent exposure to UV light (λ = 365 nm, 15 mW cm) triggered intermolecular crosslinking via the photodimerization of MTM side chains, thus resulting in the formation of polyacrylamide gels.

Multifunctional Composite Hydrogels for Bacterial Capture, Growth/Elimination, and Sensing Applications.

Hydrogels are cross-linked networks of hydrophilic polymer chains with a three-dimensional structure. Owing to their unique features, the application of hydrogels for bacterial/antibacterial studies and bacterial infection management has grown in importance in recent years. This trend is likely to continue due to the rise in bacterial infections and antimicrobial resistance.

Polymerization of Myrcene in Both Conventional and Renewable Solvents: Postpolymerization Modification via Regioselective Photoinduced Thiol-Ene Chemistry for Use as Carbon Renewable Dispersants.

Polymeric dispersants are useful materials used in many different industries and often derived from oil-based chemicals, for example, in automotive fluids so as to prevent particulates from precipitation and causing potential damage. These are very often polyisobutene derivatives, and there is a growing need to replace these using chemicals using renewable resources such as the use of naturally occurring myrcene. Polymyrcene (PMy), with an ordered microstructure, has been successfully synthesized via both anionic and radical polymerization in different solvents and subsequently subjected to functionalization via photoinduced thiol-ene click reactions with a number of thiols, methyl thioglycolate, 3-mercaptopropionic acid, 3-mercapto-1-hexanol, 2-mercaptoethanol, and 1-thioglycerol, using 2,2-dimethoxy-2-phenylacetophenone as a photoinitiator under UV irradiation (λ = 365 nm) at ambient temperature.

Photoinduced Controlled/Living Polymerizations.

The application of photochemistry in polymer synthesis is of interest due to the unique possibilities offered compared to thermochemistry, including topological and temporal control, rapid polymerization, sustainable low-energy processes, and environmentally benign features leading to established and emerging applications in adhesives, coatings, adaptive manufacturing, etc. In particular, the utilization of photochemistry in controlled/living polymerizations often offers the capability for precise control over the macromolecular structure and chain length in addition to the associated advantages of photochemistry. Herein, the latest developments in photocontrolled living radical and cationic polymerizations and their combinations for application in polymer syntheses are discussed.

Monitoring the Effect of Transdermal Drug Delivery Patches on the Skin Using Terahertz Sensing.

Water content of the skin is an important parameter for controlling the penetration rate of chemicals through the skin barrier; therefore, for transdermal patches designed for drug delivery to be successful, the effects of the patches on the water content of the skin must be understood. Terahertz (THz) spectroscopy is a technique which is being increasingly investigated for biomedical applications due to its high sensitivity to water content and non-ionizing nature. In this study, we used THz measurements of the skin (in vivo) to observe the effect of partially and fully occlusive skin patches on the THz response of the skin after the patches had been applied for 24 h.

Controlled Synthesis of Well-Defined Polyaminoboranes on Scale Using a Robust and Efficient Catalyst.

The air tolerant precatalyst, [Rh(L)(NBD)]Cl () [L = κ-(PrPCHCH)NH, NBD = norbornadiene], mediates the selective synthesis of -methylpolyaminoborane, (HBNMeH), by dehydropolymerization of HB·NMeH. Kinetic, speciation, and DFT studies show an induction period in which the active catalyst, Rh(L)H (), forms, which sits as an outer-sphere adduct as the resting state. At the end of catalysis, dormant Rh(L)HCl () is formed.

Block Copolymers Based on Ethylene and Methacrylates Using a Combination of Catalytic Chain Transfer Polymerisation (CCTP) and Radical Polymerisation.

Two scalable polymerisation methods are used in combination for the synthesis of ethylene and methacrylate block copolymers. ω-Unsaturated methacrylic oligomers (MMA ) produced by catalytic chain transfer (co)polymerisation (CCTP) of methyl methacrylate (MMA) and methacrylic acid (MAA) are used as reagents in the radical polymerisation of ethylene (E) in dimethyl carbonate solvent under relatively mild conditions (80 bar, 70 °C). Kinetic measurements and analyses of the produced copolymers by size exclusion chromatography (SEC) and a combination of nuclear magnetic resonance (NMR) techniques indicate that MMA is involved in a degradative chain transfer process resulting in the formation of (MMA) -b-PE block copolymers.

Synthesis of Poly(Lactic Acid--Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening Polymerisation.

The rise in demand for biodegradable plastic packaging with high barrier properties has spurred interest in poly(lactic acid--glycolic acid) (PLGA) copolymers with a relatively high glycolide content. In this work, we examined how reaction conditions affect the synthesis of PLGA25 (L:G 25:75) through the ring-opening polymerisation of d-l-lactide (L) and glycolide (G), using tin 2-ethylhexanoate (Sn(Oct)) as the catalyst and 1-dodecanol as the initiator. The effects of varying the initiator concentration, catalyst concentration, reaction time, and temperature on the molecular weight, monomer conversion, and thermal properties of PLGA25 were investigated.

Rapidly self-deoxygenating controlled radical polymerization in water disproportionation of Cu(i).

Rapidly Cu-RDRP in aqueous media is investigated. The disproportionation of Cu(i)/MeTren in water towards Cu(ii) and highly reactive Cu(0) leads to O-free reaction environments within the first seconds of the reaction, even when the reaction takes place in the open-air. By leveraging this significantly fast O-reducing activity of the disproportionation reaction, a range of well-defined water-soluble polymers with narrow dispersity are attained in a few minutes or less.

Cationic Glycopolymers with Aggregation-Induced Emission for the Killing, Imaging, and Detection of Bacteria.

Cationic glycopolymers with structures similar to those of typical poly(ionic liquid)s (PILs) were synthesized the quaternization reaction of poly(4-vinyl pyridine) with halogen-functionalized d-mannose and tetraphenylethylene units. Such postpolymerization modification provided PILs with aggregation-induced emission effect as well as specific carbohydrate-protein recognition with lectins such as concanavalin A. The interactions between cationic glycopolymers and different microorganisms, including Gram-positive and Gram-negative , were used for the killing, imaging, and detection of bacteria.

Self-healing and mechanical performance of dynamic glycol chitosan hydrogel nanocomposites.

The application of functional self-healing and mechanically robust hydrogels in bioengineering, drug delivery, soft robotics, etc., is continuously growing. However, fabricating hydrogels that simultaneously possess good mechanical and self-healing properties remains a challenge.

Synthesis and [2+2]-photodimerisation of monothiomaleimide functionalised linear and brush-like polymers.

[2+2]-Photodimerisation of monothiomaleimides has been demonstrated on functionalised linear and brush-like polymers. In water/acetonitrile (95 : 5) mixtures the rate of reaction is accelerated significantly by irradiation of the thiomaleimide end group (λmax = 350 nm) with UV light, reaching full conversion within 10 minutes.

Protein-polymer bioconjugates via a versatile oxygen tolerant photoinduced controlled radical polymerization approach.

The immense application potential of amphiphilic protein-polymer conjugates remains largely unexplored, as established "grafting from" synthetic protocols involve time-consuming, harsh and disruptive deoxygenation methods, while "grafting to" approaches result in low yields. Here we report an oxygen tolerant, photoinduced CRP approach which readily affords quantitative yields of protein-polymer conjugates within 2 h, avoiding damage to the secondary structure of the protein and providing easily accessible means to produce biomacromolecular assemblies. Importantly, our methodology is compatible with multiple proteins (e.

Defect-related luminescent nanostructured hydroxyapatite promotes mineralization through both intracellular and extracellular pathways.

Hydroxyapatite (HAP) is a widely used biomaterial for bone tissue substitution due to its chemical similarity with the natural bone. Defect-related luminescent HAP materials have the same chemical composition as normal HAP and excellent biocompatibility. However, only few works have focused on the defect-related luminescent HAP materials on bone regeneration.

Carboxylated Cy5-Labeled Comb Polymers Passively Diffuse the Cell Membrane and Target Mitochondria.

A detailed understanding of the cellular uptake and trafficking of nanomaterials is essential for the design of "smart" intracellular drug delivery vehicles. Typically, cellular interactions can be tailored by endowing materials with specific properties, for example, through the introduction of charges or targeting groups. In this study, water-soluble carboxylated -acylated poly(amino ester)-based comb polymers of different degree of polymerization and side-chain modification were synthesized via a combination of spontaneous zwitterionic copolymerization and redox-initiated reversible addition-fragmentation chain-transfer polymerization and fully characterized by H NMR spectroscopy and size exclusion chromatography.

Tandem Mass Spectrometry for Polymeric Structure Analysis: A Comparison of Two Common MALDI-ToF/ToF Techniques.

Tandem mass spectrometry is a powerful technique for investigating polymer architecture. However, in-depth studies of the technique for polymers is relatively lacking when compared to other areas of mass spectrometry (MS). This paper examines the use laser-induced dissociation and collision-induced dissociation (CID) in MALDI-LIFT-ToF/ToF experiments to compare the usage of the two techniques on a range of polymeric analytes.