Synthesis of ultra-high molecular weight poly(methyl methacrylate) initiated by the combination of copper nanopowder with organic halides.

In this study, organic halides, such as 2-bromobutane (CHBr), ethyl α-bromophenylacetate (BPA), ethyl 2-bromoisobutyrate (EBiB), and ethyl 2-bromopropionate (EBP) are utilized in conjunction with copper nanopowder (Nano-Cu) to initiate the polymerization of methyl methacrylate (MMA). Among these, BPA combined with nano-Cu exhibits the highest reactivity, resulting in the production of poly(methyl methacrylate) (PMMA) with a number-average molecular weight (M) of 1.91 × 10 Da, a weight-average molecular weight (M) of 3.

Lithium -butoxide-mediated efficient transesterification of -hydroxyphthalimide esters toward oxime functionalization.

We report an efficient lithium -butoxide (LiOBu)-mediated transesterification of -hydroxyphthalimide (NHPI) esters with oximes to afford oxime esters under mild conditions. This transition-metal-free method exhibits high chemoselectivity, broad substrate scope, and excellent yields (up to 99%) in acetonitrile (CHCN). Reaction optimization and scalability studies confirm its practical applicability.

Synthesis of Furan-Tethered Benzocyclobutenes via Protonic Acid-Catalyzed 1,4-Sulfinate Migration-Annulation.

A protonic acid-catalyzed cascade of conjugated enynones was realized for synthesizing multisubstituted furans containing benzocyclobutene with high yields and simple procedures. Employing inexpensive sulfanilic acid as a catalyst, this method features a key 1,4-sulfinate migration and avoids the use of transition metal catalysts. Substrates that are unreactive under metal-mediated catalysis are applicable due to proton transfer processes.

Electrochemical trifluoromethylation of alkenyl oximes for the synthesis of isoxazolines and cyclic nitrones radical annulation.

A highly efficient and environmentally friendly approach to access fluorine-containing isoxazoline and cyclic nitrone derivatives without any oxidant addition is reported. In this electrochemical system, sodium trifluoromethanesulfonate (CFSONa) serves as a practical and inexpensive trifluoromethyl source, enabling electrochemically induced radical addition and oxidative cyclization with a variety of β,γ- or γ,δ-alkenyl oxime substrates. This protocol proceeds smoothly under mild conditions and exhibits broad substrate compatibility, tolerating both electron-donating and electron-withdrawing substituents.

Recent advances in oxidative radical difunctionalization of -arylacrylamides enabled by carbon radical reagents.

The field of radical-mediated functionalization of -arylacrylamides has experienced considerable advancements in recent years, particularly in the domain of oxidative radical difunctionalization reactions employing carbon radical reagents. This approach provides a powerful and versatile strategy for the concurrent introduction of two distinct functional groups across the double bond of -arylacrylamides, facilitating the rapid construction of complex molecular architectures. This review aims to summarize the diverse strategies for inducing intramolecular transformations of -arylacrylamides using various carbon radical reagents, including methods initiated by photonic, thermal, or electrochemical processes, which have been extensively investigated by researchers.

Predicting Dinitrogen Activation by Boron Radical Cations.

Activation of dinitrogen (N) under mild conditions has been a particularly challenging project for decades, owing to the highly strong N≡N triple bond. In recent years, the main group species have emerged as a prominent strategy in the field of dinitrogen activation, but the reported examples remain particularly rare compared with transition metal complexes. Herein, we performed a comprehensive density functional theory (DFT) calculation of N activation by boron radical cations.

Two-pronged reversal of chemotherapy resistance by gold nanorods induced mild photothermal effect.

Chemotherapy treatment outcomes are severely restricted by multidrug resistance (MDR), in which tumors develop a multiple cross-resistance toward drug involving the pump and nonpump resistance mechanisms, resulting in drug efflux and defending against drug toxicity. Herein, we constructed a pH and near infrared (NIR) light responsive nanomedicine DOX@FG based on gold nanorods (GNRs) that demonstrated the potential to improve chemotherapy outcomes by overcoming MDR. DOX@FG was constructed by conjugating folic acid (FA) and doxorubicin (DOX) derivatives onto GNRs, where the DOX derivatives possessed an acid-labile hydrazone bond.

Rhodium-catalyzed intramolecular cyclization for synthesizing thiodihydropyrans.

Addressing the challenge of constructing multi-substituted dihydropyrans, we present an efficient synthesis method for oxygen-containing heterocycles. Using thiones and metal carbenes, we employed xanthate and triazole to intramolecularly synthesize dihydropyran or dihydrofuran compounds. 1,2-Hydride migration was inhibited, and thiodihydropyrans were obtained in excellent yields.

Optimizing alginate dressings with allantoin and chemical modifiers to promote wound healing.

Wound healing requires diverse functionalities in dressings, and conventional materials often fall short in water absorption and moisture regulation. Natural sodium alginate is popular in wound dressings due to its excellent film-forming ability, biocompatibility, ionic crosslinking, and pH responsiveness. However, it has limitations in physical stability and solubility in aqueous environments.

Invasive metastatic tumor-camouflaged ROS responsive nanosystem for targeting therapeutic brain injury after cardiac arrest.

Drug transmission through the blood-brain barrier (BBB) is considered an arduous challenge for brain injury treatment following the return of spontaneous circulation after cardiac arrest (CA-ROSC). Inspired by the propensity of melanoma metastasis to the brain, B16F10 cell membranes are camouflaged on 2-methoxyestradiol (2ME2)-loaded reactive oxygen species (ROS)-triggered "Padlock" nanoparticles that are constructed by phenylboronic acid pinacol esters conjugated D-a-tocopheryl polyethylene glycol succinate (TPGS-PBAP). The biomimetic nanoparticles (BM@TP/2ME2) can be internalized, mainly mediated by the mutual recognition and interaction between CD44v6 expressed on B16F10 cell membranes and hyaluronic acid on cerebral vascular endothelial cells, and they responsively release 2ME2 by the oxidative stress microenvironment.

Tumor Microenvironment-Responsive Drug Delivery Based on Polymeric Micelles for Precision Cancer Therapy: Strategies and Prospects.

In clinical practice, drug therapy for cancer is still limited by its inefficiency and high toxicity. For precision therapy, various drug delivery systems, including polymeric micelles self-assembled from amphiphilic polymeric materials, have been developed to achieve tumor-targeting drug delivery. Considering the characteristics of the pathophysiological environment at the drug target site, the design, synthesis, or modification of environmentally responsive polymeric materials has become a crucial strategy for drug-targeted delivery.

Mitigation of Anti-Drug Antibody Production for Augmenting Anticancer Efficacy of Therapeutic Protein via Co-Injection of Nano-Rapamycin.

The induction of anti-drug antibody (ADA) is a formidable challenge for protein-based therapy. Trichosanthin (TCS) as a class of ribosome-inactivating proteins is widely studied in tumor treatment. However, the immunogenicity can induce the formation of ADA, which can cause hypersensitivity reactions and neutralize the efficacy of TCS, thus limiting its clinical application in cancer therapy.

cRGD-modified nanoparticles of multi-bioactive agent conjugate with pH-sensitive linkers and PD-L1 antagonist for integrative collaborative treatment of breast cancer.

Targeted co-delivery and co-release of multi-drugs is essential to have an integrative collaborative effect on treating cancer. It is valuable to use few drug carriers for multi-drug delivery. Herein, we develop cRGD-modified nanoparticles (cRGD-TDA) of a conjugate of doxorubicin as cytotoxic agent, adjudin as an anti-metastasis agent and D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) as a reactive oxygen species inducer linked with pH-sensitive bonds, and then combine the nanoparticles with PD-L1 antagonist to treat 4T1 triple-negative breast cancer.

Structural optimization and in vivo evaluation of a colorectal stent with anti-migration and anti-tumor properties.

Clinically, colorectal stents can only palliatively relieve obstruction caused by colorectal cancer (CRC), with a high incidence of stent migration and tumor-related re-obstruction. To overcome these shortcomings, we developed a colorectal stent composed of a structure-optimized nitinol braided stent and a tubular film including an inner layer of poly (ethylene-co-vinyl acetate) (EVA) and a segmental outer layer of EVA with paclitaxel (PTX). The braiding pattern, segment number, and end shape of the stent were optimized based on the mechanical properties, ex vivo and in vivo anti-migration performance, and tissue response of the stent.

The gelling behavior of gellan in the presence of different sodium salts.

It is well known that metal ions have great effects on gelling behaviors of gellan aqueous systems, however, the effects of their co-ions - anions have rarely been studied. Herein, we investigated the effects of four kinds of sodium salts with different anions (NaCl, CHCOONa, NaCO and NaCHO) on gelling behaviors of gellan aqueous systems in terms of gelling temperature and gel hardness. It was found that, when [Na] was low (20 mM), the salt with Cl or CHCOO favored the gelling of gellan aqueous systems, while the salt with CO or CHO took adverse effects probably because CO or CHO could react with divalent cations (Ca and Mg) in gellan to form precipitates or chelates and break their interactions with gellan (salt bridges).

Preparation, characterization and primary evaluation of trilayered biliary stent films for anti-cholangiocarcinoma and anti-biofilm formation.

Excessive growth of tumor within biliary wall and formation of biofilm on inner surface of stent can cause restenosis or even obstruction after stent implantation. Therefore, it is important and valuable to develop a new biliary stent for anti-cholangiocarcinoma and anti-biofilm formation. Herein, we designed, prepared and primarily evaluated a new trilayered film for biliary stents consisting of one poly (lactic acid) (PLA) layer loaded with anti-tumor paclitaxel (PTX layer), one middle PLA isolation layer (isolation layer) and one PLA layer loaded with antimicrobial ofloxacin (OFLX layer).

Self-Assembled Micelles of Amphiphilic PEGylated Drugs for Cancer Treatment.

Generally, poor solubility and imprecise delivery of chemotherapeutic drugs can compromise their efficacies for clinical cancer treatment. In order to address such concerns, poor water-soluble drugs are conjugated with poly(ethylene glycol) (PEG) to obtain PEGylated drugs, which have improved water solubility and can also self-assemble in an aqueous solution to form micelles (PEGylated drug micelles). The surface PEG layer enhances the micelles' colloidal stability and reduces the interaction with physiological surroundings.

Moisture sorption and desorption properties of gelatin, HPMC and pullulan hard capsules.

The moisture sorption and desorption properties of hard capsules have a great influence on the quality of capsule products. However, studies on them have rarely been reported. Herein, we studied the moisture sorption and desorption properties of three kinds of hard capsules (gelatin, hydroxypropyl methyl cellulose (HPMC) and pullulan capsules) in terms of hygroscopicity, crystallinity, thermal behaviors and so on.

Effects of κ-carrageenan on pullulan's rheological and texture properties as well as pullulan hard capsule performances.

κ-Carrageenan (κ-Ca) is often used to facilitate gelling of aqueous solutions of polysaccharides. However, studies on its effects on pullulan's rheological and texture properties and pullulan (PUL) hard capsule performances have rarely been reported. Herein, effects of κ-Ca on PUL solutions, hydrogels, films and hard capsules were investigated.

Improved antibacterial properties of collagen I/hyaluronic acid/quaternized chitosan multilayer modified titanium coatings with both contact-killing and release-killing functions.

Implant infection is one of the most severe complications after orthopedic surgery. The construction of an antibacterial coating on orthopedic implants with release-killing or contact-killing is one of the most efficient strategies to prevent implant-related infections. Here we reported a hydroxypropyltrimethyl ammonium chloride chitosan (HACC) based multilayer modified plasma-sprayed porous titanium coating generated via the layer-by-layer covalent-immobilized method.

Tailor-made ternary nanopolyplexes of thiolated trimethylated chitosan with pDNA and folate conjugated cis-aconitic amide-polyethylenimine for efficient gene delivery.

To overcome the different extra-/intracellular barriers in gene delivery, tumor-targeted and pH/redox-responsive ternary polyplexes with charge-conversional properties were prepared through a modular self-assembly strategy. Firstly, the thiolated trimethylated chitosan (TMC-SH) was synthesized to crosslink and condense pDNA through electrostatic interaction and disulfide formation, which obtained the TMC-SS/pDNA binary polyplexes with redox-responsive gene release. To further endow the binary polyplexes with tumor targeting and endo/lysosomal pH-triggered charge-reversal properties, a folate conjugated cis-aconitic amide-polyethylenimine (FA-PEI-AcO) was synthesized to shield the positive TMC-SS/pDNA, generating the FA-PEI-AcO/TMC-SS/pDNA ternary polyplexes with a size of ~190 nm and negative surface-charges.

NIR-triggered release of DOX from sophorolipid-coated mesoporous carbon nanoparticles with the phase-change material 1-tetradecanol to treat MCF-7/ADR cells.

To prevent premature drug release from nanoparticles, it is vital to design and prepare controlled and site-specific drug release systems. We investigated a new controllable drug release mesoporous carbon nanoparticle (MCN)-based nano-system with the advantages of enhanced permeability and retention effect (EPR) to target tumors followed by the NIR-induced heat-triggered release of a chemotherapeutic drug to show anti-tumor effects. The pores of MCN with photo-thermal effects were filled with the chemotherapeutic agent doxorubicin (DOX) and the phase change material (PCM) 1-tetradecanol was used as a gatekeeper to trap DOX inside the pores of the mesoporous carbon nanoparticles and the release of DOX inside tumor cells was triggered using NIR irradiation.