Thiol-ene Reaction Research Articles

Biobased Sulfur- and Phosphate-Containing High-Refractive-Index Polymers: Substituent Effects on Optical Properties of Polymers.

Four biobased phosphate-containing aryl monomers with methoxy, allyl, and vinyl groups as substituents have been successfully synthesized. Copolymerizing these monomers with thiophenol or mercaptans via the photoclick thiol-ene reaction gives the polymers with refractive indices (nD) of 1.63-1.70 and Abbe numbers (vD) of 12.8-38.5. An investigation of the relationship of the vD values with the substituents on the benzene rings of the monomers indicates that methoxy and vinyl groups can collectively increase the vD values. In comparison with allyl groups, vinyl groups endow the polymers with both higher nD and vD. Moreover, these polymers also display high transmittance, high thermostability, and low haze values in the visible-light region, suggesting that these biobased functional monomers are satisfactory precursors used in the fabrication of optical devices.

Modified castor oil-based UV/thermal dual-curing polyurethane acrylate coatings with outstanding comprehensive properties

Due to the fact that single UV-cured coatings frequently fail to fulfill the requirements in terms of depth and chroma, and do not reach the ideal state in terms of comprehensive performance. In order to solve these pain-points more effectively, the sulfhydryl-modified castor oil (COME) was successfully synthesized by introducing β-mercaptoethanol onto the plant-based material castor oil (CO) through the thiol-ene clink reaction. Subsequently, the synthesized polyurethane acrylate prepolymer (COPUA), monomer, photoinitiator and thermocuring agent were used as A component, and COME was used as B component. The two were mixed evenly according to a certain proportion, and the modified castor oil based polyurethane acrylate (COMEPUA) coatings were fabricated by UV/thermal dual-curing technology. Based on a series of performance test outcomes, the coating demonstrates excellent comprehensive properties, encompassing mechanical properties (where the shear strength, tensile strength, elongation at break, and hardness can respectively reach 5.26MPa, 9.92MPa, 132.55%, and 47.77 Shore D), coating properties (where the absorption rates after 72h immersion in water, ethanol, 10wt% HCl, and 10wt% NaOH solvents are respectively 0.66, 17.98, 1.89, and 0.71%, and the volume resistivity and breakdown voltage are respectively 1.74×1016 Ω·cm and 10 KV) and curing properties (where the curing depth can reach 9.82mm, which is significantly higher than 3.51mm of single UV curing, and the colored curing is complete). It can exert protective functions such as anti-corrosion, anti-fouling, and insulation on circuit boards, electronic packaging, and device surfaces, and holds great potential in the application of coating materials.

Scalable synthesis of sulfonium and selenonium peptides for selective methyllysine reader crosslinking

Lysine methylation readers are an important class of proteins that bind site-specifically methylated proteins for downstream regulation. Chemical probes that crosslink lysine methylation readers are highly desired to investigate the proteins from cellular samples. We recently reported NleS+me2 (norleucine-ε-dimethylsulfonium) as dimethyllysine mimic selectively crosslinks corresponding methyllysine readers. Although the sulfonium tools exhibited great promise, the synthetic availability may limit broad applications. In order to incorporate the unnatural amino acid, l-Fmoc-NleSme-OH (Fmoc: fluorenyl methoxycarbonyl) was synthesized as an important building block for solid-phase peptide synthesis (SPPS) in the previous synthetic route. It took six steps with resolution of racemic mixture and radical mediated thiol-ene reaction. As a result, the synthesis was not scalable with only 4.4 % overall yield. Here we report a much-improved synthesis method so that diverse NleS+me2 peptides could be readily prepared. In addition, the new method enables preparation of selenonium peptides for methyllysine reader crosslinking. We thus believe this synthetic method will be widely used to prepare sulfonium and selenonium probes for site-selective crosslinking.

MoS2 nanosheet assisted poly vinyl alcohol cross-linked with carboxylated acryl-amido-2-methyl-1-propanesulfonic acid in medium temperature proton exchange membrane fuel cell application

ABSTRACT Initially, the carboxylated-acryl amido propane sulfonic acid (C-AMPSA) was synthesized through the thiol-ene reaction using 2-acrylamido-2-methylpropane sulfonic acid and 3-mercapto propane sulfonic acid monomers. The C-AMPSA was cross-linked with polyvinyl alcohol to create a non-perfluorinated membranes were of these acid group-containing monomers. Using a cross-linking technique, a poly vinyl alcohol cross-linked C-AMPSA (PVA-C-AMPSA) polymer was prepared. Following that, the MoS2 nanosheets (NSs) were synthesized through the one-pot hydrothermal method, and their phase purity, functionality, and morphology were evaluated by p-XRD, FT-IR, and FE-SEM analyses. These nanosheets were then incorporated into PVA-C-AMPSA polymer nanocomposite membranes at various concentrations (0%, 1%, 2%, 3%, and 5% by weight). In addition, the physicochemical properties of bare and MoS2 nanosheets incorporated PVA-C-AMPSA polymer nanocomposite membranes were assessed, including water uptake, swelling ratio, and ion-exchange capacity. Remarkably, the membrane with 5% of MoS2 NSs in PVA-C-AMPSA displayed an ion-exchange capacity of 1.13 mmol g−1 and a proton conduction of 1.8 × 10−3 S cm−1 at 110°C. The Arrhenius plot indicated that the proton transport was involved in both Grotthuss and vehicular mechanisms. In the fuel cell testing, the PVA-C-AMPSA polymer nanocomposite membrane containing MoS2 NSs demonstrated superior performance, achieving a peak power density (PD) exceeding 0.7 W cm−2 and an open-circuit voltage (OCV) surpassing 0.93 V at 110°C. In contrast, the pure PVA-C-AMPSA membrane exhibited a peak PD of over 0.4 W cm−2 and an OCV of around 0.6 V at the same temperature. Additionally, the 5% of MoS2 NSs incorporated PVA-C-AMPSA polymer nanocomposite membrane exhibited outstanding oxidative stability with 87.7% of degradation when exhibited to a Fenton reagent at 80°C for 8 h.

One-Pot Syntheses of [c2]Daisy-Chain Rotaxane Networks via Thiol-Ene Reaction and Its Application to Gel Electrolyte for Secondary Battery

One-Pot Syntheses of [c2]Daisy-Chain Rotaxane Networks via Thiol-Ene Reaction and Its Application to Gel Electrolyte for Secondary Battery

Multifunctional Polymer Synthesis via Sequential Postpolymerization Modification Using a Single Aldehyde Repeat Unit: Allylation and Orthogonal Esterification and Thiol-ene Reaction.

Herein, we present a highly efficient method for synthesizing multifunctional polymers. This method involves the sequential postpolymerization modification (PPM) of a highly reactive aldehyde polymer. We introduce an allylic alcohol functionality into the polymer backbone via Barbier-type allylation, a process facilitated by easy-to-handle indium(0) powder. This step enables the formation of orthogonal pendants, secondary alcohol, and terminal alkene, which can be further functionalized through esterification and thiol-ene click reactions. All of these processes are carried out under mild conditions, ensuring high efficiency and a wide range of functional groups. Our study underscores PPM's operational simplicity and versatility in developing advanced polymer materials and expanding the scope of multifunctional polymer design.

CHEMICAL MODIFICATION AND BIOLOGICAL ACTIVITY OF ALGINATE-BASED HYDROGELS

In recent years, the problem of wound infection has risen dramatically. Infectious complications of surgical wounds have increased significantly, often leading to severe sepsis. Gram-negative bacteria and microorganisms, which are immune to virtually all currently available antimicrobials, are the main culprits. In this regard, the development and implementation of innovative drugs and wound dressings, purulent and chronic wound treatment methods is an urgent problem of many domestic and foreign researchers. Brown algae are extracted using an alkaline solution to produce the ionic polysaccharide sodium alginate. It still holds one of the top positions among water-soluble polymers of natural origin as a result of various highly useful practical characteristics. Based on alginate hydrogels, it is possible to create new materials for biotechnological, pharmaceutical and medical purposes, as they have high moisture retention capacity, non-toxicity and self-decomposing ability. After reviewing the literature, we concluded that cefepime is a new antibiotic researched for wound dressing using IV generation cephalosporins as an antibacterial agent. It is highly resistant to hydrolysis by most beta-lactamases and quickly penetrates the cells of gram-negative bacteria. Inside the bacterial cell, it targets penicillin-binding proteins. To obtain new derivatives of sodium alginate with special properties, a chemical method, in particular, thiolene reactions, was used. It should be noted that click chemistry refers to a set of chemical reactions for the rapid and reliable synthesis of compounds by the uniform addition of individual components. Thiolene reactions offer significant advantages, includingversatile reaction conditions (including radical reactions and catalytic processes) and the ability to use a wide range of substrates with different unsaturated bonds such as acrylates, methacrylates and ethers. To monitor the rate and efficiency of UV activation, we used a sol-gel assay technique that allowed us to quantify insoluble (spatially cross-linked) and soluble polymers. After UV activation, samples with different ratios of thiol derivative (S-H bond) showed low viscosity, indicating the predominant degradation of polymer molecules in these systems. Since alginate-polymer derivatives primarily exhibit deconstructive behavior, the dominant process in alginate molecules is the breaking of bonds rather than their formation. The size of the gel fraction reflects the efficiency of polymer cross-linking, which in turn affects the efficiency of immobilization of the drug in the hydrogel matrix and its release rate. This study presents an experimental characterization of photocrosslinked hydrogels aimed at evaluating and elucidating the physicochemical and biological properties of the antibiotic cefepime in an alginate polymer. The obtained kinetic parameters of the swelling-dissolving process show that the synthesized alginate hydrogel is capable of providing a diffused and prolonged release of drugs. In addition, the synthesized hydrogel effectively delivers cefepime to the tested bacterial strains, showing high antibacterial activity without toxicity. However, further in vivo studies are needed to evaluate the fate and toxicity of the alginate-based hydrogel before definitive conclusions can be drawn regarding the usefulness of the synthesized drugs. These preliminary results can be the basis for the development of medical products.

Synthesis of vinyl functionalized polyurethane acrylate oligomers and their photopolymerization via thiol-ene click reaction

Functional polyvinylethylene glycols (PVEGs) with different central structures were synthesized by Pd/B synergistic catalysts and reacted with isophorone diisocyanate (IPDI) and 2-hydroxyethyl methacrylate(HEMA) to prepared pendent vinyl-functional polyurethane acrylates (VFPUAs). The photopolymerization of the obtained VFPUAs with pentaerythritol tetra(3-mercaptopropionate) (PETMP) in the presence of a photoinitiator proceeded smoothly via thiol-ene photo-click reaction to give a series of crosslinked materials by the variation of the chemical structure of VFPUAs and a ratio of thiols and enes. The curing behavior was studied by FT-IR and the properties of crosslinked materials were characterized by the test of gel content, swelling ratio and water absorption. The dynamic mechanical properties, mechanical properties, thermogravimetry and surface properties of the crosslinked materials were investigated and the performance of coating for the crosslinked film materials was also characterized. The crosslinked film materials can be further functionalized by post-crosslinking modification through thiol-ene photo-click reaction.

UV-crosslinked SBS block copolymers via thiol-ene reaction for efficient absorption and removal of oil/organic solvents from water

With the urgent need for oil/organic solvents spills disposal, the development of new sorbents with low cost, high sorption capacity, good selectivity and reusability is required. In the current work, three-dimensional structured absorbents have been rapidly fabricated by ultraviolet (UV)-crosslinking of styrene-block-butadiene-block-styrene (SBS) copolymers via thiol-ene reaction in 60 s, using poly-(mercaptopropyl)methylsiloxane (SMS) as crosslinker. The SBS-SMS absorbents were characterized by FT-IR, SEM, XRD, tensile strength, thermogravimetric, gel fraction and water contact angle analysis, which showed high tensile strength, good thermal stability, hydrophobicity, and acceptable gel content. The absorption capacity investigations were carried out in 7 types of organic liquids and 2 types of oils. The SBS-SMS0.005 exhibited the highest absorption performance in different organics, with the capacities of 74.6 g/g for dichloromethane, 20.1 g/g for kerosene, and 12.8 g/g for diesel oil, respectively. The impacts of sheet thickness on the absorption and desorption kinetics were studied, and the results showed that thinner absorbents illustrated faster absorption and desorption speed. Additionally, the SBS-SMS absorbents showed good selectivity and effectiveness in organic solvents/oil separation from water (separation efficiency > 93 %), well oil retention ability and oil desorption efficiency, floating properties, easy collection, as well as good reusability upon ten absorption-desorption cycles. The current SBS-SMS absorbents should have great potential in practical application for efficient oil/water separation as well as radioactive organic waste liquid treatment.

Ionic Polybenzimidazoles Crosslinked through Thiol-Ene Reactions for Anion Exchange Membranes

This research introduces a study outlining the synthesis and characteristics of innovative anion exchange membranes that utilize m-polybenzimidazole (m-PBI) as the polymer backbone structure. These membranes incorporate quaternary ammonium groups and alkene groups as side chains. These ionic m-PBI membranes were further crosslinked through thermal thiol-ene reactions. By adeptly manipulating the quantities of attached quaternary ammonium groups and alkene groups, the ion exchange capacity (IEC) values and crosslinking degrees were independently controlled. A comprehensive range of m-PBI based anion exchange membranes was developed, showcasing IEC values ranging from 1.51 to 2.50 mmol/g. This series of membranes demonstrated hydroxide conductivity levels ranging between 14 and 58 mS/cm at an operational temperature of 80 °C. Particularly noteworthy is the comparison between membranes with similar IEC values: the crosslinked membranes exhibited reduced water absorption while effectively maintaining a level of hydroxide conductivity comparable to that of uncrosslinked membranes. Moreover, the crosslinked membranes exhibited enhanced dimensional stability. An intriguing finding emerged from a crosslinked membrane with an IEC value of 2.46 mmol/g, which retained a remarkable 84% of its original hydroxide conductivity after being immersed in a 1.0 M sodium hydroxide solution at 60 °C for a duration of 720 hours. These membranes demonstrated mechanical strength even in their hydrated state, exhibiting tensile strengths ranging from 10.8 to 14.6 MPa. Given their heightened hydroxide conductivity, improved resistance to alkaline conditions, and favorable mechanical attributes, the crosslinked ionic m-PBIs emerge as promising candidates for anion exchange membranes in fuel cell applications. Keywords ; anion exchange membranes, crosslinking reaction, polybenzimidazole, back titration, mechanical strength.

A Facile One-Step Conversion of Biobased Magnolol (Honokiol) toward High Refractive Materials.

A series of polymers with both high refractive index and high Abbe number have been successfully synthesized through the photoclick thiol-ene reaction between the monomers derived from biobased magnolol (or honokiol) and commercial mercaptans and thiophenols. The polymer films not only exhibit a high refractive index and a high Abbe number but also display a transmittance of up to 90% in a range of wavelengths from 550 to 2000 nm and nearly 0% in the UV region. Moreover, these polymers also display low haze values in the visible-light region as well as exhibit good thermostability. These data indicate that they have potential applications for the fabrication of optical lenses and anti-UV coatings. In particular, this series of polymers are readily used for industrialization due to its excellent optical properties but low expense, simplicity, and efficiency of synthesis.

Zwitterionic channels within covalent organic frameworks facilitate proton-selective transport for flow battery membrane

Flow batteries demand for ion conductive membranes (ICMs) with high ion selectivity to achieve efficient energy conversion. Herein, we engineered a cysteine-modified covalent organic framework (Cys-COF) by a Thiol-ene click reaction. As a promising proton carrier, the incorporation of the Cys-COF with sulfonated poly(ether ketone) (SPEEK) yields advanced ICMs for vanadium flow batteries (VFBs). The zwitterionic cysteine groups anchored on the nanochannel walls simultaneously narrowed the pore size and ameliorated the protophilicity of Cys-COF, resulting in improved vanadium permeating resistance and proton conductivity. As a result, the optimal membrane demonstrated synchronized improvements in coulombic efficiency (95.01 %–98.84 %), voltage efficiency (95.15 %–77.84 %) and energy efficiency (90.41 %–76.94 %) with the current densities ranging from 40 to 200 mA cm−2. Regarding stability test, it achieved exceptional energy efficiency (∼84.3 %) over 1100 cycles and 550 h at the constant current density of 120 mA cm−2, outperforming pure polymer membrane and Nafion 212.

Synthesis of palm oil-based bio-polyol by thiol-ene reaction: Preliminary study of its potential as cationic waterborne polyurethane for coating application

Thailand has the world's third-largest planting area for oil palm. Palm oil can be chemically modified to obtain bio-polyol instead of petroleum-based polyol. In this research, a new bio-polyol based on modified palm oil (MPO) was successfully synthesized by thiol-ene click reaction using Darocur1173 as a photoinitator. The molar ratios 2-Mercaptoethanol (ME) to carbon‑carbon double bonds for MPO synthesis was studied. The kinetics of the thiol-ene click reaction was investigated by monitoring with 1H NMR technique. The chemical structure of MPO was confirmed by 1HNMR and FTIR spectroscopy. In addition, the average molecular weight (Mn) of a series of MPO was determined by GPC. The influence of N-methyl diethanolamine (NMDEA) content as an internal emulsifier on cationic waterborne polyurethane (cWPU) was investigated. The resulting cWPU based on MPO showed well-dispersed particles with a shelf life of >6 months and the zeta potential increased with increasing NMDEA content ranging from 5.6 % to 9.6 %wt. Moreover, the plywood with cWPU coatings had a shiny gloss surface, with increasing NMDEA content. The cWPU coating with NMDEA content lower than 7.6 %wt protected the plywood surface against QUV accelerated weathering for 48 h without cracking the cWPU film. The cWPU showed a high gloss value, decreased contact angle, and increased water absorption behavior. The hydrophilicity of cWPU film increased with increasing NMDEA content. Also, increasing the NMDEA content led to a higher ratio of hard segment to soft segment in the PU chain which improved the tensile strength and thermal stability. These results demonstrated an efficient synthesis procedure which offers an opportunity to use palm oil as bio-polyol to develop green cWPU that can be used as a binder in coating applications.

Stabilized Carbon-Centered Radical-Mediated Carbosulfenylation of Styrenes: Modular Synthesis of Sulfur-Containing Glycine and Peptide Derivatives.

Sulfur-containing amino acids and peptides play critical roles in organisms. Thiol-ene reactions between the thiol residues of L-cysteine and the alkenyl fragments in the designed coupling partners serve as primary tools for constructing C─S bonds in the synthesis of unnatural sulfur-containing amino acid derivatives. These reactions are favored due to the preference for hydrogen transfer from thiol to β-sulfanyl carbon radical intermediates. In this paper, the study proposes utilizing carbon-centered radicals stabilized by the capto-dative effect, generated under photocatalytic conditions from N-aryl glycine derivatives. The aim is to compete with the thiol hydrogen, enabling radical C─C bond formation with β-sulfanyl carbon radicals. This protocol is robust in the presence of air and water, offers significant potential as a modular and efficient platform for synthesizing sulfur-containing amino acids and modifying peptides, particularly with abundant disulfides and styrenes.

Mechanical properties of co-continuous network polymers packed with thiol-ene thermosets in epoxy monolith

Co-continuous network polymers (CNPs) as the new polymer composites are fabricated by filling the continuous pores of an epoxy monolith with a high glass transition temperature (Tg) using another kind of network polymer with a low Tg. In this study, we prepared sheet-like and cylindrical CNPs using thiol–ene thermosets as the second component with a low Tg. A thiol–ene reaction is suitable for the preparation of thermosets with a controlled network structure. Here, various thiols and acrylates including the different numbers of functional groups and/or oligo(ethylene oxide) spacers with different lengths are used for the fabrication of the second thermosetting component. We investigated the tensile and compression mechanical properties of the produced CNPs. Dynamic mechanical analysis (DMA) of the thiol–ene bulk thermosets (BTs) as the second component was also carried out in order to clarify the influence of the Tg and the crosslinking density on the mechanical and physical properties of the CNPs. The results of the mechanical tests were discussed on the functionality of the used acrylate and thiol compounds. In conclusion, we have revealed that the properties of CNPs are not only dependent on the crosslinking density, but also significantly affected by the detailed network structure of the second component.

Chitosan-based hydrogels: Influence of crosslinking strategy on rheological properties

The effect of two crosslink strategies on the preparation of chitosan-based covalent hydrogels was investigated employing the widely used thiol-ene reaction. This versatile “click” chemistry can be activated either photochemically or thermochemically. Initially, well-purified chitosan (CS, DA ∼4 %, Mw ∼580 kg mol−1) was separately functionalized with vinyl (CS-ene) or thiol (CS-SH) groups in aqueous media. Subsequently, two strategies were compared where thiol-ene reaction occurs respectively between: (S1) modified chitosans CS-ene and CS-SH, in a polymer – polymer strategy, and (S2) CS-ene and di(ethylene glycol) dithiol (dEG-(SH)2), in a polymer – molecule strategy.Both crosslinking strategies were evaluated through rheological measurements, starting with entangled chitosan solutions. The difference in diffusion of functional groups, whether attached to polymer chains or to free molecules, leads to faster gelation kinetics with S2. Consequently, stronger gels were obtained with S2, where the modulus was connected with the degree of functionalization, while S1 produced weaker gels closer to the percolation point, where crosslinked density was associated with the entanglement number derived from the initial concentration. Nevertheless, networks formed by both strategies were homogenous with minimal dissipative contributions to their rheological properties, indicating that structural defects are negligible.

One-step functionalization and polymer grafting potential of green silica derived from rice husk ash

Green silica has been synthesized from rice husk ash which exempts the landfilling of agricultural waste and the requirement of higher temperature for digestion, unlike the conventional mode of silica synthesis making the process of precipitation and functionalization sustainable. An energy-efficient method of functionalization has been optimized for the synthesis of functionalized silica from rice husk ash via co-condensation. The potential for providing better reinforcement leads silica to be used as filler in composite manufacturing. To obtain a better silica-polymer interaction, nitroxide functionalized silica has been synthesized over three different types of silica samples using different processes. The nitroxide functionalities were introduced by thiol-ene reaction between 4-acryloyloxy(2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and mercaptopropyl functionalized silica particles. The mercaptopropyl functionalized silica was synthesized by post-modification as well as co-condensation over commercial precipitated silica, commercial rice husk ash silica, and silica synthesized in the lab from sodium silicate obtained from rice husk ash. By comparing mercaptopropyl and nitroxide grafting density, it has been observed that the nitroxide loading highly depends on the method of functionalization and the co-condensed samples show higher nitroxide loading compared to the post-modified samples. The nitroxide functionalized samples were further subjected to polystyrene grafting, and the efficiency of surface nitroxide radicals in capturing the polymer radicals with respect to nitroxide loading was determined. The grafting density was observed to increase with the increase in conversion and the increase in the initiator-to-monomer ratio. However, the grafting density was observed to be saturated at some point despite having a higher surface area and surface nitroxide radicals. The study can be used to tune the surface nitroxide radical concentration and surface area for optimum polymer grafting for engineering applications.

Ring-opening polymerization of six-membered cyclic hybrid dimers composed of an oxoester and thioester

Three cyclic oxoester-thioester hybrid monomers, 1 (3-methyl-1,4-oxathiane-2,5-dione), 2 (6-methyl-1,4-oxathiane-2,5-dione), and 3 (3,6-dimethyl-1,4-oxathiane-2,5-dione), were studied for anionic and cationic ring-opening polymerizations. These monomers are six-membered cyclic cross-dimers corresponding to combinations of glycolic and lactic acids with their thiol analogs. Anionic polymerizations using thiol as the initiator and 2,6-lutidine as the base catalyst were successful for the chemoselective cleavage of the thioester with the thiol propagating end. The polymerizability increased in the order of 3 < 1 < 2, which was in good agreement with the increasing ring strain order evaluated by Density Functional Theory calculations. The living character, to some extent, was suggested by the postpolymerization reactions, which involved a two-stage feed of the monomers and a thiol-ene terminal coupling reaction to form a block copolymer with PEG. Additionally, it was found that the polymerization took place in 2,6-lutidine without a thiol initiator and produced macrocyclic polymers. The cationic polymerizations took place with the aid of CF3SO3H and benzyl alcohol but involved side reactions with low chemoselective ring cleavage. The thioester unit caused the polymers to exhibit a lower Tg with greater thermal and photo degradability.

Construction of hyaluronic acid-functionalized magnolol nanoparticles for ulcerative colitis treatment

Oral targeted anti-inflammatory drugs have garnered significant interest in treating ulcerative colitis (UC) due to their potential in reducing medical costs and enhancing treatment efficacy. Magnolol (Mag), a natural anti-inflammatory compound, has demonstrated protective effects against UC. However, its application as an alternative therapeutic agent for UC is limited by poor gastrointestinal stability and inadequate accumulation at inflamed colonic lesions. This study introduces a novel nanoparticle (NPs) formulation based on Mag, functionalized with hyaluronic acid (HA) for targeted UC therapy. Bovine serum albumin (BSA) was modified with 2-thiamine hydrochloride to synthesize BSA·SH. Thiol-ene click reaction with Mag led to the formation of BSA·SH-Mag NPs, which were further modified with HA through dehydration condensation, regular spherical inflammation-targeting HA-BSA·SH-Mag nanoparticles with a charge of −23.6 mV and a particle size of 403 ± 4 nm were formed. In vitro studies revealed significant macrophage targeting and enhanced uptake by colon epithelial cells. Oral administration of HA-BSA·SH-Mag facilitated colon mucosal barrier repair by modulating pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), anti-inflammatory cytokines (IL-10), and tight junction proteins (ZO-1, Claudin, Occludin). Crucially, HA-BSA·SH-Mag was found to inhibit the JAK2/STAT3/NF-κB signaling pathway, reducing DSS-induced colon tissue inflammation. This research provides valuable insights into the oral use of natural compounds in UC therapy, highlighting the therapeutic potential of HA-BSA·SH-Mag NPs.

Self-healing photo-polymerized thiol-ene networks utilizing bio-based hexaallylated compounds derived from L-cystine and citric acid

Bio-based vitrimers have received considerable attention owing to their contributions to carbon neutrality and resource and energy savings. The photopolymerization of hexaallylated compounds (A6CST and A6UDC) derived from L-cystine and citric acid with disulfide-containing polyether dithiol (LP-12) and pentaerythritol-based tetrathiol (S4P) at an allyl:thiol ratio of 1:1 produced thiol-ene network films. Fourier-transform infrared spectroscopy of the cured films revealed that the thiol-ene reaction of the thiol and allyl groups was almost complete. Degrees of swelling of the cured films decreased with an increasing LP-12/S4P ratio. The A6CST- and A6UDC-cured films with higher flexible LP-12 fractions (i.e., higher disulfide contents) exhibited lower glass transition temperatures (Tgs), tensile strengths, and tensile moduli, and could be healed by treatment at a lower temperature and shorter time. The A6CST/S4P cured film was healed by treating at 100 ℃ for 24 h, whereas the A6UDC/S4P cured film without disulfide bond was not healed by the same treatment. The A6CST-based film with the highest LP-12/S4P ratio exhibited the highest healing efficiency (99 %) after treatment at room temperature for 10 h, and self-healed at least three times.