Synthesis and Characterization of Graft Copolymers with Poly(ε-caprolactone) Side Chain Using Hydroxylated Poly(ß-myrcene-co-α-methyl styrene).

Graft copolymers have unique application scenarios in the field of high-performance thermoplastic elastomers, resins and rubbers. ß-myrcene (My) is a biomass monomer derived from renewable plant resources, and its homopolymer has a low glass transition temperature and high elasticity. In this work, a series of tapered copolymers P(My-co-AMS)k (k = 1, 2, 3) were first synthesized in cyclohexane by one-pot anionic polymerization of My and α-methyl styrene (AMS) using sec-BuLi as the initiator. PAMS chain would fracture when heated at high temperature and could endow the copolymer with thermal degradation property. The effect of the incorporation of AMS unit on the thermal stability and glass transition temperature of polymyrcene main chain was studied. Subsequently, the double bonds in the linear copolymers were partially epoxidized and hydroxylated into hydroxyl groups to obtain hydroxylated copolymer, which was finally used to initiate the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) to synthesize the graft copolymer with PCL as the side chain. All these copolymers before and after modifications were characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), thermogravimetry analysis (TGA), and differential scanning calorimeter (DSC).

ABC-Type, Bola-Form Giant Surfactants: Synthesis and Self-Assembly.

Due to the fast phase separation kinetics and small feature size, the self-assembly of giant molecules has attracted lots of attention. However, there is not much study on multicomponent giant surfactants. In this work, through a modular synthetic strategy, different polyhedral oligomeric silsesquioxane (POSS)-based molecular nanoparticles are installed with diverse functionalities (hydrophobic octavinyl POSS (VPOSS), hydrophilic dihydroxyl-functionalized POSS (DPOSS), and omniphobic perfluoroalkyl-chain-functionalized POSS (FPOSS)) on the ends of one polystyrene (PS) chain to build up a series of triblock bola-form giant surfactants denoted as XPOSS-PSn -FPOSS (X represents V or D). The target molecules are prepared by a combination of atom transfer radical polymerization (ATRP), esterification, as well as Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) and thiol-ene "click" reactions. These macromolecules are thoroughly characterized by combined technologies including nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses. It is revealed by small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) that VPOSS-PSn -FPOSS adopts a two-phase separation scenario where VPOSS and POSS are segregated in one phase. DPOSS-PSn -FPOSS with a third hydrophilic DPOSS shows a three-phase separation scenario, where highly ordered phase structures are difficult to develop owing to the competition of mutual phase separation processes and may be trapped in kinetically metastable states.

METTL3 Regulates Osteoclast Biological Behaviors via iNOS/NO-Mediated Mitochondrial Dysfunction in Inflammatory Conditions.

Excessive differentiation of osteoclasts contributes to the disruption of bone homeostasis in inflammatory bone diseases. Methyltransferase-like 3 (METTL3), the core methyltransferase that installs an N6-methyladenosine (m6A) modification on RNA, has been reported to participate in bone pathophysiology. However, whether METTL3-mediated m6A affects osteoclast differentiation in inflammatory conditions remains unelucidated. In this study, we observed that the total m6A content and METTL3 expression decreased during LPS-induced osteoclastogenesis. After knocking down METTL3, we found reduced levels of the number of osteoclasts, osteoclast-related gene expression and bone resorption area. A METTL3 deficiency increased osteoclast apoptosis and pro-apoptotic protein expression. RNA sequencing analysis showed that differentially expressed genes in METTL3-deficient cells were mainly associated with the mitochondrial function. The expression of the mitochondrial function-related genes, ATP production and mitochondrial membrane potential decreased after METTL3 knockdown. Moreover, the most obviously upregulated gene in RNA-Seq was Nos2, which encoded the iNOS protein to induce nitric oxide (NO) synthesis. METTL3 knockdown increased the levels of Nos2 mRNA, iNOS protein and NO content. NOS inhibitor L-NAME rescued the inhibited mitochondrial function and osteoclast formation while suppressing osteoclast apoptosis in METTL3-silenced cells. Mechanistically, a METTL3 deficiency promoted the stability and expression of Nos2 mRNA, and similar results were observed after m6A-binding protein YTHDF1 knockdown. Further in vivo evidence revealed that METTL3 knockdown attenuated the inflammatory osteolysis of the murine calvaria and suppressed osteoclast formation. In conclusion, these data suggested that METTL3 knockdown exacerbated iNOS/NO-mediated mitochondrial dysfunction by promoting a Nos2 mRNA stability in a YTHDF1-dependent manner and further inhibited osteoclast differentiation and increased osteoclast apoptosis in inflammatory conditions.

Glucose-Sensitive Core-Cross-Linked Nanoparticles Constructed with Polyphosphoester Diblock Copolymer for Controlling Insulin Delivery.

This work aims to construct biocompatible, biodegradable core-cross-linked and insulin-loaded nanoparticles which are sensitive to glucose and release insulin via cleavage of the nanoparticles in a high-concentration blood glucose environment. First, a polyphosphoester-based diblock copolymer (PBYP-g-Gluc)-b-PEEP was prepared via ring-opening copolymerization (ROP) and the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) in which PBYP and PEEP represent the polymer segments from 2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane and 2-ethoxy-2-oxo-1,3,2-dioxaphospholane, respectively, and Gluc comes from 2-azidoethyl-ß-d-glucopyranoside (Gluc-N3) that grafted with PBYP. The structure and molecular weight of the copolymer were characterized by 1H NMR, 31P NMR, GPC, FT-IR, and UV-vis measurements. The amphiphilic copolymer could self-assemble into core-shell uncore-cross-linked nanoparticles (UCCL NPs) in aqueous solutions and form core-cross-linked nanoparticles (CCL NPs) after adding cross-linking agent adipoylamidophenylboronic acid (AAPBA). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to study the self-assembly behavior of the two kinds of NPs and the effect of different Gluc group contents on the size of NPs further to verify the stability and glucose sensitivity of CCL NPs. The ability of NPs to load fluorescein isothiocyanate-labeled insulin (FITC-insulin) and their glucose-triggered release behavior were detected by a fluorescence spectrophotometer. The results of methyl thiazolyl tetrazolium (MTT) assay and hemolysis activity experiments showed that the CCL NPs had good biocompatibility. An in vivo hypoglycemic study has shown that FITC-insulin-loaded CCL NPs could reduce blood glucose and have a protective effect on hypoglycemia. This research provides a new method for constructing biodegradable and glucose-sensitive core-cross-linked nanomedicine carriers for controlled insulin release.

Agonists of growth hormone-releasing hormone (GHRH) inhibit human experimental cancers in vivo by down-regulating receptors for GHRH.

The effects of the growth hormone-releasing hormone (GHRH) agonist MR409 on various human cancer cells were investigated. In H446 small cell lung cancer (SCLC) and HCC827 and H460 (non-SCLC) cells, MR409 promoted cell viability, reduced cell apoptosis, and induced the production of cellular cAMP in vitro. Western blot analyses showed that treatment of cancer cells with MR409 up-regulated the expression of cyclins D1 and D2 and cyclin-dependent kinases 4 and 6, down-regulated p27kip1, and significantly increased the expression of the pituitary-type GHRH receptor (pGHRH-R) and its splice-variant (SV1). Hence, in vitro MR409 exerts agonistic action on lung cancer cells in contrast to GHRH antagonists. However, in vivo, MR409 inhibited growth of lung cancers xenografted into nude mice. MR409 given s.c. at 5 µg/day for 4 to 8 weeks significantly suppressed growth of HCC827, H460, and H446 tumors by 48.2%, 48.7%, and 65.6%, respectively. This inhibition of tumor growth by MR409 was accompanied by the down-regulation of the expression of pGHRH-R and SV1 in the pituitary gland and tumors. Tumor inhibitory effects of MR409 in vivo were also observed in other human cancers, including gastric, pancreatic, urothelial, prostatic, mammary, and colorectal. This inhibition of tumor growth parallel to the down-regulation of GHRH-Rs is similar and comparable to the suppression of sex hormone-dependent cancers after the down-regulation of receptors for luteinizing hormone-releasing hormone (LHRH) by LHRH agonists. Further oncological investigations with GHRH agonists are needed to elucidate the underlying mechanisms.

Fabrication of Polymeric Ferrocene Nanoparticles for Electrochemical Aptasensing of Protein with Target-Catalyzed Hairpin Assembly.

Herein we describe a novel isothermal and enzyme-free electrochemical aptasensor for protein detection via the employment of polymeric ferrocene nanoparticles (PFcNPs) and target-catalyzed hairpin assembly amplification. The synthesized PFcNPs not only load numerous Fc molecules for enhanced electrochemical output but also possess plenty of amino groups, which increase the water solubility and facilitate the conjugation with the aptamer toward the recognition of target protein. After the formation of an aptamer/protein complex, the conformation of the DNA probe changes, which further triggers hairpin assembly on top of DNA tetrahedral structures modified on the electrode interface. The process can be recycled, and multiple PFcNPs are localized on the electrode. Thus, an amplified electrochemical signal is able to be recorded, which is sufficient to achieve a demonstrated limit of detection as low as 67 fM. This developed aptasensor can also discriminate target protein from other interfering substances with a high selectivity. Furthermore, it has been successfully applied in diluted real blood serum samples. All of these features make the present methodology a promising candidate for ultratrace protein biosensors.

Efficient Click Synthesis of a Protonized and Reduction-Sensitive Amphiphilic Small-Molecule Prodrug Containing Camptothecin and Gemcitabine for a Drug Self-Delivery System.

Drug self-delivery systems consisting of small-molecule active drugs with nanoscale features for intracellular delivery without the need for additional polymeric carriers have drawn much attention recently. In this work, we proposed a highly efficient strategy to fabricate protonized and reduction-responsive self-assembled drug nanoparticles from an amphiphilic small-molecule camptothecin-ss-1,2,3-triazole-gemcitabine conjugate (abbreviated as CPT-ss-triazole-GEM) for combination chemotherapy, which was prepared via a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reaction. To obtain this drug-triazole-drug conjugate, we first prepared a CPT derivate containing a propargyl group linked with a disulfide group and a GEM derivate attached to an azide group. Subsequently, the two kinds of modified drugs were connected together through a CuAAC reaction between the alkynyl and azide groups to yield the CPT-ss-triazole-GEM prodrug. The characterizations of chemical structures of these intermediates and the final product were performed by 1H NMR, Fourier transform infrared, and liquid chromatography/mass spectrometry measurements. This amphiphilic small-molecule drug-triazole-drug conjugate displayed a high drug loading content, that is, 36.0% of CPT and 27.2% of GEM. This kind of amphiphilic small-molecule prodrugs could form spherical nanoparticles in an aqueous solution in the absence of any other polymeric carriers, in which the hydrophobic CPT formed the core of the nanoparticles, whereas the hydrophilic GEM and protonated 1,2,3-triazole group yielded the shell. In the tumor microenvironment, the prodrug nanoparticles could release both pristine drugs simultaneously. Under the conditions of pH 7.4, and pH 7.4 and 2 µM glutathione (GSH), the prodrug nanoparticles could maintain stability and only 7% of CPT was leaked. However, in a high-GSH environment (pH 7.4 and 10 mM GSH) with the same incubation time, the disulfide linkage would be dissociated and lead to about 34% of CPT release. The results of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test demonstrated that these prodrug nanoparticles showed a higher cytotoxicity toward HepG2 cells than free CPT and free GEM on both 48 and 72 h of incubation. Both in vitro cellular uptake and flow cytometry results implied that these prodrug nanoparticles could be internalized by HepG2 cells with efficient drug release inside cells. The pharmacokinetics and tissue distribution of the prodrug showed a moderate half-life in vivo, and the prodrug peak concentration in most of the collected tissues appeared at 0.25 h after administration. In addition, the CPT-ss-triazole-GEM prodrug could not cross the blood-brain barrier. Even more important is the fact that there is no accumulation in tissues and a rapid elimination of this small-molecule prodrug could be achieved. In brief, this protonized and reduction-sensitive prodrug simultaneously binds both antitumor drugs and has good self-delivery behavior through the donor-acceptor interaction of the H-bonding ligand, that is, the 1,2,3-triazole group. It provides a new method for combined drug therapy.

Geometry induced sequence of nanoscale Frank-Kasper and quasicrystal mesophases in giant surfactants.

Frank-Kasper (F-K) and quasicrystal phases were originally identified in metal alloys and only sporadically reported in soft materials. These unconventional sphere-packing schemes open up possibilities to design materials with different properties. The challenge in soft materials is how to correlate complex phases built from spheres with the tunable parameters of chemical composition and molecular architecture. Here, we report a complete sequence of various highly ordered mesophases by the self-assembly of specifically designed and synthesized giant surfactants, which are conjugates of hydrophilic polyhedral oligomeric silsesquioxane cages tethered with hydrophobic polystyrene tails. We show that the occurrence of these mesophases results from nanophase separation between the heads and tails and thus is critically dependent on molecular geometry. Variations in molecular geometry achieved by changing the number of tails from one to four not only shift compositional phase boundaries but also stabilize F-K and quasicrystal phases in regions where simple phases of spheroidal micelles are typically observed. These complex self-assembled nanostructures have been identified by combining X-ray scattering techniques and real-space electron microscopy images. Brownian dynamics simulations based on a simplified molecular model confirm the architecture-induced sequence of phases. Our results demonstrate the critical role of molecular architecture in dictating the formation of supramolecular crystals with "soft" spheroidal motifs and provide guidelines to the design of unconventional self-assembled nanostructures.

One-Pot Synthesis of pH/Redox Responsive Polymeric Prodrug and Fabrication of Shell Cross-Linked Prodrug Micelles for Antitumor Drug Transportation.

Shell cross-linked (SCL) polymeric prodrug micelles have the advantages of good blood circulation stability and high drug content. Herein, we report on a new kind of pH/redox responsive dynamic covalent SCL micelle, which was fabricated by self-assembly of a multifunctional polymeric prodrug. At first, a macroinitiator PBYP- ss- iBuBr was prepared via ring-opening polymerization (ROP), wherein PBYP represents poly[2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane]. Subsequently, PBYP- hyd-DOX- ss-P(DMAEMA- co-FBEMA) prodrug was synthesized by a one-pot method with a combination of atom transfer radical polymerization (ATRP) and a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction using a doxorubicin (DOX) derivative containing an azide group to react with the alkynyl group of the side chain in the PBYP block, while DMAEMA and FBEMA are the abbriviations of N, N-(2-dimethylamino)ethyl methacrylate and 2-(4-formylbenzoyloxy)ethyl methacrylate, respectively. The chemical structures of the polymer precursors and the prodrugs have been fully characterized. The SCL prodrug micelles were obtained by self-assembly of the prodrug and adding cross-linker dithiol bis(propanoic dihydrazide) (DTP). Compared with the shell un-cross-linked prodrug micelles, the SCL prodrug micelles can enhance the stability and prevent the drug from leaking in the body during blood circulation. The average size and morphology of the SCL prodrug micelles were measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The SCL micelles can be dissociated under a moderately acidic and/or reductive microenvironment, that is, endosomal/lysosomal pH medium or high GSH level in the tumorous cytosol. The results of DOX release also confirmed that the SCL prodrug micelles possessed pH/reduction responsive properties. Cytotoxicity and cellular uptake analyses further revealed that the SCL prodrug micelles could be rapidly internalized into tumor cells through endocytosis and efficiently release DOX into the HeLa and HepG2 cells, which could efficiently inhibit the cell proliferation. This study provides a fast and precise synthesis method for preparing multifunctional polymer prodrugs, which hold great potential for optimal antitumor therapy.

Fabrication of Thermosensitive Cyclic Brush Copolymer with Enhanced Therapeutic Efficacy for Anticancer Drug Delivery.

Adaptation of cyclic brush polymer for drug delivery applications remains largely unexplored. Herein, cyclic brush copolymer of poly(2-hydroxyethyl methacrylate-g-poly(N-isopropylacrylamide-st-N-hydroxyethylacrylamide)) (cb-P(HEMA-g-P(NIPAAm-st-HEAAm))), comprising a cyclic core of PHEMA and thermosensitive brushes of statistical copolymer of P(NIPAAm-st-HEAAm), is designed and synthesized successfully via a graft-from approach using atom transfer free radical polymerization from a cyclic multimacroinitiator. The composition of the brush is optimized to endow the resulting cyclic brush copolymer with a lower critical solution temperature (LCST) slightly above the physiological temperature, but lower than the localized temperature of tumor tissue, which is suitable for the hyperthermia-triggered anticancer drug delivery. Critical aggregation concentration determination reveals better stability for the unimolecular nanoparticle formed by the cyclic brush copolymer than that formed by the bottlebrush analogue. The dramatically increased size with elevated temperatures from below to above the LCST confirms hyperthermia-induced aggregation for both formulations. Such structural destabilization promotes significantly the drug release at 40 °C. Most importantly, the drug-loaded cyclic brush copolymer shows enhanced in vitro cytotoxicity against HeLa cells than the bottlebrush counterpart. The better stability and higher therapeutic efficacy demonstrates that the thermosensitive cyclic brush copolymer is a better formulation than bottle brush copolymer for controlled drug release applications.

Beneficial effects of growth hormone-releasing hormone agonists on rat INS-1 cells and on streptozotocin-induced NOD/SCID mice.

Agonists of growth hormone-releasing hormone (GHRH) have been previously reported to promote growth, function, and engraftment of islet cells following transplantation. Here we evaluated recently synthesized GHRH agonists on the proliferation and biological functions of rat pancreatic ß-cell line (INS-1) and islets. In vitro treatment of INS-1 cells with GHRH agonists increased cell proliferation, the expression of cellular insulin, insulin-like growth factor-1 (IGF1), and GHRH receptor, and also stimulated insulin secretion in response to glucose challenge. Exposure of INS-1 cells to GHRH agonists, MR-356 and MR-409, induced activation of ERK and AKT pathways. Agonist MR-409 also significantly increased the levels of cellular cAMP and the phosphorylation of cAMP response element binding protein (CREB) in INS-1 cells. Treatment of rat islets with agonist, MR-409 significantly increased cell proliferation, islet size, and the expression of insulin. In vivo daily s.c. administration of 10 µg MR-409 for 3 wk dramatically reduced the severity of streptozotocin (STZ)-induced diabetes in nonobese diabetic severe combined immunodeficiency (NOD/SCID) mice. The maximal therapeutic benefits with respect to the efficiency of engraftment, ability to reach normoglycemia, gain in body weight, response to high glucose challenge, and induction of higher levels of serum insulin and IGF1 were observed when diabetic mice were transplanted with rat islets preconditioned with GHRH agonist, MR-409, and received additional treatment with MR-409 posttransplantation. This study provides an improved approach to the therapeutic use of GHRH agonists in the treatment of diabetes mellitus.

Synthesis of PEGylated Ferrocene Nanoconjugates as the Radiosensitizer of Cancer Cells.

Radiation is one of the most widely used methods for cancer diagnosis and therapy. Herein, we report a new type of radiation sensitizer (Fc-PEG) by a facile one-step reaction of conjugating the hydrophilic PEG chain with hydrophobic ferrocene molecule. The chemical composition and structure of Fc-PEG have been thoroughly characterized by FT-IR, NMR, GPC, and MALDI-TOF mass spectrometry. This Fc-PEG conjugate could self-assemble in aqueous solution into spherical aggregates, and it was found that the exposure to 4 Gy of X-ray radiation have little influence on the shape and size of these aggregates. After the chemical bonding with PEG chains, the uptake level of Fe element could be enhanced via the formation of aggregates. The live/dead, CCK-8, as well as apoptosis assays, indicated that the death of cancer cells can be obviously increased by X-ray radiation after the incubation of these Fc-based nanoconjugates, which might be served as the radiation sensitizer toward cancer cells. We suggest that this radiosensitizing effect comes from the enhancement of reactive oxygen specimen (ROS) level as denoted by both flow cytometric and fluorescence microscopic analysis. The enhanced radiation sensitivity of cancer cells is contributed by the synergic effect of Fe-induced radiation-sensitizing and the increased uptake of nanoconjugates after polymeric grafting.

A nanomedicine composed of polymer-ss-DOX and polymer-Ce6 prodrugs with monoclonal antibody targeting effect for anti-tumor chemo-photodynamic synergetic therapy.

Anticancer drugs used for systemic chemotherapy often exhibit off-target toxicity and uncontrolled drug release due to their lack of targeting. To improve the bioavailability of drugs and reduce side effects, we have developed a mixed micelle of nanomedicine composed of two prodrugs with surface modified monoclonal antibody for cancer therapy. In this system, Nimotuzumab was used as targeting ligands of the mixed micelles (named as DCMMs) that is composed of polymer-doxorubicin prodrug (abbreviated as PEG-b-P(GMA-ss-DOX)) and maleimide polyethylene glycol-chlorin e6 (abbreviated as Mal-PEG-Ce6). The mixed micelles modified with Nimotuzumab (named as NTZ-DCMMs) bind to overexpressed EGFR receptors on Hepatoma-22 (H22) cells. Disulfide bonds in PEG-b-P(GMA-ss-DOX) are disrupted in tumor microenvironment, inducing the reduction-responsive release of DOX and leading to tumor cell apoptosis. Simultaneously, Chlorin e6 (Ce6) produced plenty of singlet oxygen (1O2) under laser irradiation to kill tumor cells. In vivo biological distribution and antineoplastic effect experiments demonstrate that NTZ-DCMMs enhanced drug enrichment at tumor sites through targeting function of antibody, dramatically suppressing tumor growth and mitigating cardiotoxicity of drugs. All results prove that NTZ-DCMMs have the ability to actively target H22 cells and quickly respond to tumor microenvironment, which is expected to become an intelligent and multifunctional drug delivery carrier for efficient chemotherapy and photodynamic therapy of hepatoma. STATEMENT OF SIGNIFICANCE: Anticancer drugs used for systemic chemotherapy often exhibit off-target toxicity due to their lack of targeting. Therefore, it's necessary to develop effective, targeted, and collaborative treatment strategies. We construct a mixed micelle of nanomedicine based on two polymer prodrugs and modified with monoclonal antibody on surface for cancer therapy. Under the tumor cell microenvironment, the disulfide bonds of polymer-ss-DOX were broken, effectively triggering DOX release. The photosensitizer Ce6 could generate a large amount of ROS under light, which synergistically promotes tumor cell apoptosis. By coupling antibodies to the hydrophilic segments of polymer micelles, drugs can be specifically delivered. Compared with monotherapy, the combination of chemotherapy and photodynamic therapy can significantly enhance the therapeutic effect of liver cancer.

FTO regulates osteoclast development by modulating the proliferation and apoptosis of osteoclast precursors in inflammatory conditions.

Periodontitis is an oral inflammatory disease that causes alveolar bone destruction by activating osteoclast. FTO, a crucial demethylase of N6-methyladenosine(m6A), exerts essential function in maintaining bone homeostasis. However, the effects of FTO on periodontitis-related bone destruction remain unknown. To investigate its role in inflammatory osteoclastogenesis, we overexpressed FTO in osteoclast precursor cells; RNA-seq revealed that differentially expressed genes were mainly enriched in cell cycle, DNA replication, DNA damage response and apoptosis in FTO overexpression cells during RANKL and LPS-stimulated osteoclast differentiation. FTO overexpression upregulated the expression of S phase-related proteins (Cyclin A2, CDK2), and decreased the expression of DNA damage related proteins in osteoclast precursor cells. FTO promoted cell proliferation demonstrated by EdU and CCK8 assay, and reduced apoptotic rate and the expression of apoptosis-related proteins in osteoclast precursor cell. Conversely, FTO inhibitor FB23-2 produced the reverse effect. Mechanistically, FTO overexpression promoted the stability of CyclinA2 and CDK2 mRNA. These results were consistent in m6A binding protein YTHDF2 knockdown cells. Moreover, FB23-2 suppressed osteoclast-related gene expression, osteoclast formation and bone resorption ability. Treatment of FB23-2 reduced the alveolar bone loss in mice of experimental periodontitis. Collectively, our findings revealed that FTO enhanced the mRNA stability and expression of Cyclin A2, CDK2 in a YTHDF2-dependent manner in osteoclast precursor cells, promoted cell proliferation and inhibited cell apoptosis. FB23-2 reduced the formation of osteoclasts, resulted in alleviating the bone destruction in periodontitis mice. These findings indicated that FTO might be the potential target of the treatment of bone loss in periodontitis.

METTL3 promotes osteoblast ribosome biogenesis and alleviates periodontitis.

BACKGROUND: Periodontitis is a highly prevalent oral disease characterized by bacterium-induced periodontal inflammation and alveolar bone destruction. Osteoblast function is impaired in periodontitis with a global proteome change. METTL3 is the pivotal methyltransferase of N6-methyladenosine (m6A) that is recently proved to exert a crucial role in osteoblast differentiation. This study aims to investigate the role of METTL3 in osteoblast ribosome biogenesis in periodontitis progression. RESULTS: METTL3 was knocked down in osteoblasts, and the downregulated genes were enriched in ribosome and translation. METTL3 knockdown inhibited ribosome biogenesis and oxidative phosphorylation in LPS-stimulated osteoblasts, whereas METTL3 overexpression facilitated ribosomal and mitochondrial function. Mechanistically, METTL3 mediated osteoblast biological behaviors by activating Wnt/ß-catenin/c-Myc signaling. METTL3 depletion enhanced the mRNA expression and stability of Dkk3 and Sostdc1 via YTHDF2. In periodontitis mice, METTL3 inhibitor SAH promoted alveolar bone loss and local inflammatory status, which were partially rescued by Wnt/ß-catenin pathway activator CHIR-99021 HCl. CONCLUSIONS: METTL3 promoted ribosome biogenesis and oxidative phosphorylation by activating Wnt/ß-catenin/c-Myc signaling in LPS-treated osteoblasts and alleviated the inflammatory alveolar bone destruction in periodontitis mice.

Development of multifunctional ionogels derived from a dynamic deep eutectic solvent.

A new polymerizable and dynamic deep eutectic solvent (DES) consisting of choline chloride and α-lipoic acid is proposed. By virtue of thermally-initiated ring-opening polymerization (ROP) of cyclic disulfide and multiple dynamic interactions (disulfide, hydrogen, and coordination bonds), multifunctional ionogels with good comprehensive properties are developed and explored as potential flexible conductors.

Dextran-doxorubicin prodrug nanoparticles conjugated with CD147 monoclonal antibody for targeted drug delivery in hepatoma therapy.

Antibody-drug conjugates (ADCs) are a class of tumor cell-targeting drugs that have developed rapidly in recent years. From the perspective of further improving ADC targeting and developing natural macromolecules as drug carriers, it is still challenging and necessary to try new targeted drug delivery modalities. In this study, we have developed an antibody-modified prodrug nanoparticle based on biomacromolecule dextran (DEX) to delivery antitumour drug doxorubicin (DOX). Firstly, oxidized dextran (ODEX) and DOX were bonded to yield ODEX-DOX via Schiff base reaction, which can self-assemble into nanoparticles (NPs) carrying some aldehyde groups. Subsequently, the amino groups of CD147 monoclonal antibody were bound to the aldehyde groups on the surface of ODEX-DOX NPs, resulting in acid-responsive and antibody-modified CD147-ODEX-DOX NPs with relatively small particle size and high DOX loading. FT-IR, UV-Vis, HPLC, and 1H NMR were used to demonstrate the successful synthesis of polymer prodrug ODEX-DOX NPs and antibody-modified nanomedicine CD147-ODEX-DOX NPs. Dynamic light scattering (DLS) was used to evaluate the stability and the pH responsiveness of ODEX-DOX NPs in different media and tumour microenvironment. The in vitro total release content of DOX reached approximately 70% in PB 5.0 buffer solution after 103 h. Furthermore, the in vivo antitumour efficacy and biodistribution experiments confirmed that CD147-ODEX-DOX NPs could significantly inhibit the growth of HepG2 tumour. All of the results indicate that this acid-sensitive nanomedicine has higher safety and targeting effects. It promises to be an ideal strategy for future targeted drug delivery systems and anticancer therapies.

A CD326 monoclonal antibody modified core cross-linked curcumin-polyphosphoester prodrug for targeted delivery and cancer treatment.

Stimuli-responsive cross-linked micelles (SCMs) are ideal nanocarriers for anti-cancer drugs. Compared with non-cross-linked micelles, SCMs exhibit superior structural stability. At the same time, the introduction of an environmentally sensitive crosslinker into a drug delivery system allows SCMs to respond to single or multiple stimuli in the tumor microenvironment, which can minimize drug leakage during the blood circulation process. In this study, curcumin (CUR) was modified as the hydrophobic core crosslinker by utilizing the bisphenol structure, and redox sensitive disulfide bonds were introduced to prepare the glutathione (GSH) stimulated responsive core crosslinker (abbreviated as N3-ss-CUR-ss-N3). In addition, amphiphilic polymer APEG-b-PBYP was prepared through the ring opening reaction, and reacted with the crosslinker through the "click" reaction. After being dispersed in the aqueous phase, core cross-linked nanoparticles (CCL NPs) were obtained. Finally, monoclonal antibody CD326 (mAb-CD326) was reduced and coupled to the hydrophilic chain ends to obtain the nanoparticles with surface modified antibodies (R-mAb-CD326@CCL NPs) for further enhancing targeted drug delivery. The structures of the polymer and crosslinker were characterized by 1H NMR, UV-Vis, FT-IR, and GPC. The morphology, size and stability of CCL NPs and R-mAb-CD326@CCL NPs were investigated by DLS and TEM. The in vitro drug release behavior of CCL NPs was also studied. The results showed that the CCL NPs exhibited reduction-responsiveness and were able to release the original drug CUR under 10 mM GSH conditions. Additionally, the CCL NPs exhibited excellent stability in both the simulated body fluid environment and organic solvents. Especially, R-mAb-CD326@CCL NPs can actively target tumor cells and showed better therapeutic efficacy in in vivo experiments with a tumor suppression rate of 78.7%. This work provides a new idea for the design of nano-drugs targeting breast cancer.

Unexpected mechanically robust ionic conductive elastomer constructed from an itaconic acid-involved polymerizable DES.

An ionic conductive elastomer with good comprehensive properties is constructed from a ternary polymerizable deep eutectic solvent (PDES) containing choline chloride, acrylic acid and itaconic acid (IA). The IA component is found to boost the synergetic hydrogen bonds and greatly improve the mechanical strength of elastomer.

A hybrid hydrogel constructed using drug loaded mesoporous silica and multiple response copolymer as an intelligent dressing for wound healing of diabetic foot ulcers.

Traditional wound dressings have poor mechanical properties and a single function, which cannot achieve rapid healing of diabetic wounds in a unique physiological microenvironment. In order to develop multifunctional hydrogel dressings with appropriate biological activity to accelerate wound healing and obtain better clinical therapeutic effects, herein we report a hybrid system based on drug loaded mesoporous silica and injectable polymer hydrogels mixed with hypoglycemic drug metformin (Met) as a dressing for diabetic wounds. Firstly, a copolymer with the phenylboronic acid group in the side group, poly(acrylamide-co-dimethylaminopropylacrylamide-co-methacrylamidophenylboronic acid) (abbreviated as PB), was prepared. PB was mixed with polyvinyl alcohol (PVA) to obtain an injectable hydrogel (named PP) with pH/glucose dual responsiveness, which was formed through the combination of the phenylborate group of PB and o-diol of PVA. In another reaction, polydopamine-modified mesoporous silica nanoparticles (MSN@PDA) were prepared and used to adsorb antibiotic tetracycline hydrochloride (TH) to obtain drug-loaded MSN@PDA-TH nanoparticles. Subsequently, the hybrid hydrogel dressing (abbreviated as PP/MSN@PDA-TH/Met) was obtained by mixing PB, PVA, Met and MSN@PDA-TH. The self-healing, rheological and adhesive properties of the hybrid hydrogel were characterized. The results show that the hydrogel dressing has good physical properties. Met and TH were released in vitro in different pH media and glucose environments. The results show that the hydrogel dressing has dual responsiveness towards pH and glucose, and can continuously release metformin and tetracycline, which is conducive to accelerating wound healing. The antimicrobial activity, ROS clearance ability and biocompatibility of the hydrogel dressing were evaluated. The results indicate that the hydrogel dressing was multifunctional. Finally, a full-thickness wound repair model of diabetic mice induced by streptozotocin (STZ) was established. The hybrid hydrogel dressing was applied to the wound surface of mice. The wound healing testing on diabetic mice confirmed that the wound covered with the hybrid hydrogel dressing was completely healed with the formation of the new skin and hair within 9 days to 12 days. Histological analysis indicates that, compared to the PBS control, the hydrogel dressing did not cause significant inflammation in the wound, and a large number of blood vessels, glands and hair follicles appeared. This study provides a good strategy for multi-drug synergistic treatment of diabetic foot ulcers.