A first-in-class POLRMT specific inhibitor IMT1 suppresses endometrial carcinoma cell growth.

Exploring novel molecularly-targeted therapies for endometrial carcinoma is important. The current study explored the potential anti-endometrial carcinoma activity by a first-in-class POLRMT (RNA polymerase mitochondrial) inhibitor IMT1. In patient-derived primary human endometrial carcinoma cells and established lines, treatment with IMT1 potently inhibited cell viability, proliferation, cell-cycle progression and motility, while inducing robust caspase-apoptosis activation. Treatment with the PLORMT inhibitor impaired mitochondrial functions, leading to mtDNA (mitochondrial DNA) transcription inhibition, mitochondrial membrane potential decline, reactive oxygen species formation, oxidative stress and ATP loss in the endometrial carcinoma cells. Similarly, POLRMT depletion, through shRNA-induced silencing or CRISPR/Cas9-caused knockout (KO), inhibited primary endometrial carcinoma cell proliferation and motility, and induced mitochondrial dysfunction and apoptosis. Importantly, IMT1 failed to induce further cytotoxicity in POLRMT-KO endometrial carcinoma cells. Contrarily, ectopic overexpression of POLRMT further augmented proliferation and motility of primary endometrial carcinoma cells. In vivo, oral administration of a single dose of IMT1 substantially inhibited endometrial carcinoma xenograft growth in the nude mice. mtDNA transcription inhibition, oxidative stress, ATP loss and apoptosis were detected in IMT1-treated endometrial carcinoma xenograft tissues. Together, targeting PLORMT by IMT1 inhibited endometrial carcinoma cell growth in vitro and in vivo.

Ferroptosis in Cancer Progression: Role of Noncoding RNAs.

Ferroptosis is a novel form of programmed cell death, and it is characterized by iron-dependent oxidative damage, lipid peroxidation and reactive oxygen species accumulation. Notable studies have revealed that ferroptosis plays vital roles in tumor occurrence and that abundant ferroptosis in cells can inhibit tumor progression. Recently, some noncoding RNAs (ncRNAs), particularly microRNAs, long noncoding RNAs, and circular RNAs, have been shown to be involved in biological processes of ferroptosis, thus affecting cancer growth. However, the definite regulatory mechanism of this phenomenon is still unclear. To clarify this issue, increasing studies have focused on the regulatory roles of ncRNAs in the initiation and development of ferroptosis and the role of ferroptosis in progression of various cancers, such as lung, liver, and breast cancers. In this review, we systematically summarized the relationship between ferroptosis-associated ncRNAs and cancer progression. Moreover, additional evidence is needed to identify the role of ferroptosis-related ncRNAs in cancer progression. This review will help us to understand the roles of ncRNAs in ferroptosis and cancer progression and may provide new ideas for exploring novel diagnostic and therapeutic biomarkers for cancer in the future.

Keap1-targeting microRNA-941 protects endometrial cells from oxygen and glucose deprivation-re-oxygenation via activation of Nrf2 signaling.

BACKGROUND: Mimicking ischemia-reperfusion injury, oxygen and glucose deprivation (OGD)-re-oxygenation (OGDR) applied to endometrial cells produces significant oxidative stress and programmed necrosis, which can be inhibited by nuclear-factor-E2-related factor 2 (Nrf2) signaling. MicroRNA (miRNA)-induced repression of Keap1, a Nrf2 suppressor protein that facilitates Nrf2 degradation, is novel strategy to activate Nrf2 cascade. METHODS: MicroRNA-941 (miR-941) was exogenously expressed in HESC and primary human endometrial cells, and the Nrf2 pathway examined by Western blotting and real-time quantitative PCR analysis. The endometrial cells were treated with OGDR, cell programmed necrosis and apoptosis were tested. RESULTS: MiR-941 is a novel Keap1-targeting miRNA that regulates Nrf2 activity. In T-HESC cells and primary human endometrial cells, ectopic overexpression of miR-941 suppressed Keap1 3'-UTR (untranslated region) expression and downregulated its mRNA/protein expression, leading to activation of the Nrf2 cascade. Conversely, inhibition of miR-941 elevated Keap1 expression and activity in endometrial cells, resulting in suppression of Nrf2 activation. MiR-941 overexpression in endometrial cells attenuated OGDR-induced oxidative stress and programmed necrosis, whereas miR-941 inhibition enhanced oxidative stress and programmed necrosis. MiR-941 overexpression and inhibition were completely ineffective in Keap1-/Nrf2-KO T-HESC cells (using CRISPR/Cas9 strategy). Restoring Keap1 expression, using an UTR-depleted Keap1 construct, abolished miR-941-induced anti-OGDR activity in T-HESC cells. Thus Keap1-Nrf2 cascade activation is required for miR-941-induced endometrial cell protection. CONCLUSIONS: Targeting Keap1 by miR-941 activates Nrf2 cascade to protect human endometrial cells from OGDR-induced oxidative stress and programmed necrosis. Video Abstract.

Keratinocyte growth factor protects endometrial cells from oxygen glucose deprivation/re-oxygenation via activating Nrf2 signaling.

Oxygen and glucose deprivation (OGD)-re-oxygenation (OGDR) exposure to endometrial cells mimics ischemia-reperfusion injury. The present study tests the potential effect of keratinocyte growth factor (KGF) on the process. We show that KGF receptor KGFR is expressed in human endometrial T-HESC cells and primary murine endometrial cells. KGF pre-treatment protected endometrial cells from OGDR, inhibiting cell viability reduction and cell death. KGF attenuated OGDR-induced programmed necrosis in endometrial cells. Significantly, KGF activated Nrf2 signaling, causing Nrf2 Ser-40 phosphorylation, protein stabilization, nuclear translocation to promote anti-oxidant gene (HO1, NOQ1 and GCLC) expression. Nrf2 silencing (by targeted shRNAs) or CRISPR/Cas9 knockout almost abolished KGF-induced endometrial cell protection against OGDR. Furthermore, KGF activated Akt-mTOR signaling in endometrial cells. Whereas Akt-mTOR inhibitors (LY294002, AZD2014 and RAD001) abolished KGF-induced Nrf2 activation and anti-OGDR cytoprotection. Together, KGF protects endometrial cells from OGDR via activating Akt-mTOR-Nrf2 signaling.

Analogous ß-Carboline Alkaloids Harmaline and Harmine Ameliorate Scopolamine-Induced Cognition Dysfunction by Attenuating Acetylcholinesterase Activity, Oxidative Stress, and Inflammation in Mice.

The analogous ß-carboline alkaloids, harmaline (HAL) and harmine (HAR), possess a variety of biological properties, including acetylcholinesterase (AChE) inhibitory activity, antioxidant, anti-inflammatory, and many others, and have great potential for treating Alzheimer's disease (AD). However, studies have showed that the two compounds have similar structures and in vitro AChE inhibitory activities but with significant difference in bioavailability. The objective of this study was to comparatively investigate the effects of HAL and HAR in memory deficits of scopolamine-induced mice. In the present study, mice were pretreated with HAL (2, 5, and 10 mg/kg), HAR (10, 20, and 30 mg/kg) and donepezil (5 mg/kg) by intragastrically for 7 days, and were daily intraperitoneal injected with scopolamine (1 mg/kg) to induce memory deficits and then subjected to behavioral evaluation by Morris water maze. To further elucidate the underlying mechanisms of HAL and HAR in improving learning and memory, the levels of various biochemical factors and protein expressions related to cholinergic function, oxidative stress, and inflammation were examined. The results showed that HAL and HAR could effectively ameliorate memory deficits in scopolamine-induced mice. Both of them exhibited an enhancement in cholinergic function by inhibiting AChE and inducing choline acetyltransferase (ChAT) activities, and antioxidant defense via increasing the antioxidant enzymes activities of superoxide dismutase and glutathione peroxidase, and reducing maleic diadehyde production, and anti-inflammatory effects through suppressing myeloperoxidase, tumor necrosis factor α, and nitric oxide as well as modulation of critical neurotransmitters such as acetylcholine (ACh), choline (Ch), L-tryptophan (L-Trp), 5-hydroxytryptamine (5-HT), γ-aminobutyric acid (γ-GABA), and L-glutamic acid (L-Glu). Furthermore, the regulations of HAL on cholinergic function, inflammation, and neurotransmitters were more striking than those of HAR, and HAL manifested a comparable antioxidant capacity to HAR. Remarkably, the effective dosage of HAL (2 mg/kg) was far lower than that of HAR (20 mg/kg), which probably due to the evidently differences in the bioavailability and metabolic stability of the two analogs. Taken together, all these results revealed that HAL may be a promising candidate compound with better anti-amnesic effects and pharmacokinetic characteristics for the treatments of AD and related diseases.

Core-shell structure of Fe3O4@MTX-LDH/Au NPs for cancer therapy.

Nearly monodispersed magnetic Fe3O4@MTX-LDH/Au nanoparticles (NPs) containing the anticancer agent of methotrexate (MTX) were prepared via a coprecipitation-electrostatic interaction strategy. Firstly, layered double hydroxide (LDH) materials were deposited over the surface of Fe3O4 NPs by the coprecipitation method. Secondly, Au NPs were successfully conjugated onto the surface of LDH through electrostatic interaction. Herein, MTX was used both as the agent for surface modification and the anticancer drug for chemotherapy. These particles presented well-defined core-shell structure, strong magnetization and a high drug-loading capacity. Furthermore, the combined treatment of cancer cells by using Fe3O4@MTX-LDH/Au for synergistic hyperthermia ablation and chemotherapy was demonstrated to exhibit higher therapeutic efficacy than either single treatment alone, underscoring the great potential of the platform for cancer therapy.

Induction of Au-methotrexate conjugates by sugar molecules: production, assembly mechanism, and bioassay studies.

Au-methotrexate (Au-MTX) conjugates induced by sugar molecules were produced by a simple, one-pot, hydrothermal growth method. Herein, the Au(III)-MTX complexes were used as the precursors to form Au-MTX conjugates. Addition of different types of sugar molecules with abundant hydroxyl groups resulted in the formation of Au-MTX conjugates featuring distinct characteristics that could be explained by the diverse capping mechanisms of sugar molecules. That is, the instant-capping mechanism of glucose favored the generation of peanut-like Au-MTX conjugates with high colloidal stability while the post-capping mechanism of dextran and sucrose resulted in the production of Au-MTX conjugates featuring excellent near-infrared (NIR) optical properties with a long-wavelength plasmon resonance near 630-760 nm. Moreover, in vitro bioassays showed that cancer cell viabilities upon incubation with free MTX, Au-MTX conjugates doped with glucose, dextran and sucrose for 48 h were 74.6%, 55.0%, 62.0%, and 63.1%, respectively. Glucose-doped Au-MTX conjugates exhibited a higher anticancer activity than those doped with dextran and sucrose, therefore potentially presenting a promising treatment platform for anticancer therapy. Based on the present study, this work may provide the first example of using biocompatible sugars as regulating agents to effectively guide the shape and assembly behavior of Au-MTX conjugates. Potentially, the synergistic strategy of drug molecules and sugar molecules may offer the possibility to create more gold-based nanocarriers with new shapes and beneficial features for advanced anticancer therapy.

Novel morphologies of poly(allyamine hydrochloride)-methotrexate nanoassemblies for methotrexate delivery.

Poly(allylamine hydrochloride)-methotrexate (PAH-MTX) nanoassemblies with novel morphologies (i.e. nanostrips, nanorolls, nanosheets, and nanospheres) were achieved for the first time via supramolecular self-assembly directed by the synergistic action of various non-covalent interactions between PAH and MTX molecules in aqueous solution. Herein, MTX acted in a versatile manner as both a morphology-regulating agent and a small molecular hydrophobic anticancer drug. Moreover, different morphologies presented diverse drug release profiles, which may be caused by the distinctive interactions between PAH and MTX molecules. Synergistically non-covalent interactions, including electrostatic interactions, van der Waals forces, and hydrogen bonding, favored easier matrix corrosion and more rapid drug release of non-spherical structures (i.e. nanostrips, nanorolls, and nanosheets) through the ligand exchange process. On the other hand, the highly sealed encapsulation mode for hydrophobic MTX molecules made the nanospheres exhibit slower and better controlled release. In addition, in vitro bioassay tests showed that nanostrips displayed the most obvious suppression on the viability of cancer cells among other morphologies, especially after a longer duration. The strategy of using small molecular anticancer drugs not as passively delivered cargoes but as effective molecular building blocks, opens up a new way to develop self-delivering drugs for anticancer therapy.

Immune Tolerance Effect in Mesenteric Lymph Node Lymphocytes of Geniposide on Adjuvant Arthritis Rats.

Rheumatoid arthritis (RA) is a systemic, Th1 cytokine-predominant autoimmune disease result in a chronic and inflammatory disorder. Geniposide (GE), an iridoid glycoside compound that is purified from Gardenia jasminoides Ellis, has antiinflammatory and other immunoregulatory effects, but its exact mechanism of actions on RA is unknown. The aim of this study was to elucidate antiinflammation effects of GE on adjuvant arthritis (AA) rats and its possible immune tolerance mechanisms. Male Sprague-Dawley rats were administered with GE (30, 60, and 120 mg/kg) orally from day 17 to 24 after immunization. Lymphocyte proliferation was assessed by MTT. Levels of interleukin-2 (IL-2), IL-4, and transforming growth factor-ß1 were tested by ELISA. The expression of ß2-AR, GRK2, and ß-arrestin-1 and ß-arrestin-2 was detected by western blot. Geniposide was found to relieve the secondary hind paw swelling and arthritis scores, along with attenuating histopathologic changes and decreasing IL-2 and increasing IL-4, transforming growth factor-ß1 in mesenteric lymph node (MLN) lymphocytes of AA rats. In addition, GE in vivo increased the expression of ß2-AR and decreased the expression of GRK2, ß-arrestin-1 and ß-arrestin-2, and level of cyclic adenosine monophosphate of MLN lymphocytes in AA rats. From these results, we can infer that GE on immune tolerance effects, ß2-AR desensitization, and ß2-AR-AC-cyclic adenosine monophosphate transmembrane signal transduction of MLN lymphocytes plays crucial roles in antiinflammatory and immunoregulatory pathogeneses of RA. Copyright © 2017 John Wiley & Sons, Ltd.

Novel morphology change of Au-Methotrexate conjugates: From nanochains to discrete nanoparticles.

A novel morphology change of Au-methotrexate (Au-MTX) conjugates that could transform from nanochains to discrete nanoparticles was achieved by a simple, one-pot, and hydrothermal growth method. Herein, MTX was used efficiently as a complex-forming agent, reducing agent, capping agent, and importantly a targeting anticancer drug. The formation mechanism suggested a similarity with the molecular imprinting technology. The Au-MTX complex induced the MTX molecules to selectively adsorb on different crystal facets of gold nanoparticles (AuNPs) and then formed gold nanospheres. Moreover, the abundantly binding MTX molecules promoted directional alignment of these gold nanospheres to further form nanochains. More interestingly, the linear structures gradually changed into discrete nanoparticles by adding different amount of ethylene diamine tetra (methylene phosphonic acid) (EDTMPA) into the initial reaction solution, which likely arose from the strong electrostatic effect of the negatively charged phosphonic acid groups. Compared with the as-prepared nanochains, the resultant discrete nanoparticles showed almost equal drug loading capacity but with higher drug release control, colloidal stability, and in vitro anticancer activity.

Equilibrium and kinetic modeling of iron adsorption and the effect by chloride, sulfate, and hydroxyl: evaluation of PVC-U drinking pipes.

The update of pipeline was quick over the last few years and the plastic pipes were widely used in the drinking water distribution systems (DWDSs), especially in the small-diameter pipes. In this study, the iron adsorptive characteristics and the affecting factors in unplasticized poly(vinyl chloride) (PVC-U) pipe were investigated. Results showed that the average amount of iron in the 10-year-old PVC-U pipe's interior surface was 2.80 wt% which was almost 187 times larger than that in a new one. Goethite (α-FeOOH) and magnetite (Fe3O4) were the major iron compounds in the scales which covered on the old pipes' interior surface and showed loose and porous images under a scanning electron microscope. Moreover, the influence of the iron concentration on the adsorption amount and rate was discussed. The adsorption amount was significantly influenced by iron concentration, but similar adsorption rate was discovered. Notably, iron was quantitatively adsorbed by PVC-U pipe during the experimental period in accordance with the pseudo second order kinetic model. Meanwhile, regression model and response surface methodology were used to analyze the regular of iron adsorption in different concentrations of chloride (Cl-), sulfate (SO42-), and hydroxyl (OH-). It can be concluded that Cl- and OH- showed the strong ability of iron adsorption which were larger than SO42-.

Methotrexate intercalated calcium carbonate nanostructures: Synthesis, phase transformation and bioassay study.

The formation and stabilization of amorphous calcium carbonate (ACC) is an active area of research owing to the presence of stable ACC in various biogenic minerals. In this paper, the synthesis of calcium carbonate (CaCO3) under the participation of methotrexate (MTX) via a facile gas diffusion route was reported. The results indicated that the addition of MTX can result in the phase transformation of CaCO3, and then two kinds of hybrids, i.e., MTX-vaterite and stable MTX-ACC came into being. Interestingly, the functional agent MTX served as both the target anticancer drug loaded and effective complexation agents to modify and control the morphology of final samples. The examination of MTX-ACC biodegradation process revealed that the collapse of MTX-ACC nanoparticles was due to the synergistic effect of drug release and the phase transformation. Finally, our study also proved that MTX-ACC exhibited the most excellent suppressing function on the viability of cancer cells, especially after long-time duration.

Plasma miRNA-506 as a Prognostic Biomarker for Esophageal Squamous Cell Carcinoma.

BACKGROUND MicroRNAs (miRNAs) are responsible for regulating proliferation, differentiation, apoptosis, invasion, and metastasis in tumor cells. miRNA-506 is abnormally expressed in multiple tumors, indicating that it might be oncogenic or tumor-suppressive. However, little is known about the association between miRNA-506 expression and esophageal squamous cell carcinoma (ESCC). MATERIAL AND METHODS We examined the expression of miRNA-506 in the plasma of ESCC patients using quantitative real-time polymerase chain reaction (qRT-PCR) to determine the association between miRNA-506 expression and clinicopathological features of ESCC. ROC curves were produced for ESCC diagnosis by plasma miRNA-506 and the area under curve was calculated to explore its diagnostic value. RESULTS Average miRNA-506 expression levels were remarkably higher in the plasma of ESCC patients than in healthy volunteers (P<0.001). The expression of miRNA-506 in the plasma was closely associated with lymph node status (P=0.004), TNM stage (P=0.031), and tumor length (P<0.001). According to ROC curves, the area under the curve for plasma miRNA-506 was 0.835, indicating statistical significance for ESCC diagnosis by plasma miRNA-506 (P<0.001). Kaplan-Meier analysis showed that patients with high miRNA-506 expression had significantly shorter survival time than those with low miRNA-506 expression. Cox regression analysis demonstrated that T stage, N stage, tumor length, and miRNA-506 expression levels were significantly correlated with prognosis in ESCC patients. CONCLUSIONS miRNA-506 can serve as an important molecular marker for diagnosis and prognostic prediction of ESCC.

Detection of Circulating Tumor Cells by Fluorescent Immunohistochemistry in Patients with Esophageal Squamous Cell Carcinoma: Potential Clinical Applications.

BACKGROUND Circulating tumor cells (CTCs) are tumor cells that leave the primary tumor site and enter the bloodstream, where they can spread to other organs; they are very important in the diagnosis, treatment, and prognosis of malignant tumors. However, few studies have investigated CTCs in esophageal squamous cell carcinoma (ESCC). The aim of this study was to investigate the CTCs in blood of ESCC patients and its potential relevance to clinicopathological features and prognosis. MATERIAL AND METHODS CTCs were acquired by a negative enrichment method that used magnetic activated cell sorting (MACSTM). Fluorescent immunohistochemistry (IHC) was used to identify the CTCs. Then, the positive CTC patients with ESCC were analyzed, after which the relationship between CTCs and clinicopathologic features was evaluated. RESULTS In the present study, 62 out of 140 (44.3%) patients with ESCC were positive for CTCs. The positive rate of CTCs was significantly related with stage of ESCC patients (P=0.013). However, there was no relationship between CTC status and age, sex, smoking tumor history, tumor location, differentiation of tumor, lymphatic invasion, or lymph venous invasion (P>0.05). Kaplan-Meier analysis showed that patients positive for CTCs had significantly shorter survival time than patients negative for CTCs. Multivariate analysis demonstrated that stage and CTC status were significant prognostic factors for patients with ESCC. CONCLUSIONS CTCs positivity is an independent prognostic biomarker that indicates a worse prognosis for patients with ESCC.

A novel platform designed by Au core/inorganic shell structure conjugated onto MTX/LDH for chemo-photothermal therapy.

A novel platform making up of methotrexate intercalated layered double hydroxide (MTX/LDH) hybrid doped with gold nanoparticles (NPs) may have great potential both in chemo-photothermal therapy and the simultaneous drug delivery. In this paper, a promising platform of Au@PDDA-MTX/LDH was developed for anti-tumor drug delivery and synergistic therapy. Firstly, Au NPs were coated using Layer-by-Layer (LbL) technology by alternate deposition of poly (diallyldimethylammonium chloride) (PDDA) and MTX molecules, and then the resulting core-shell structures (named as Au@PDDA-MTX) were directly conjugated onto the surface of MTX/LDH hybrid by electrostatic attraction to afford Au@PDDA-MTX/LDH NPs. Here MTX was used as both the agent for surface modification and the anti-tumor drug for chemotherapy. The platform of Au@PDDA-MTX/LDH NPs not only had a high drug-loading capacity, but also showed excellent colloidal stability and interesting pH-responsive release profile. In vitro drug release studies demonstrated that MTX released from Au@PDDA-MTX/LDH was relatively slow under normal physiological pH, but it was enhanced significantly at a weak acidic pH value. Furthermore, the combined treatment of cancer cells by using Au@PDDA-MTX/LDH for synergistic hyperthermia ablation and chemotherapy was demonstrated to exhibit higher therapeutic efficacy than either single treatment alone, underscoring the great potential of the platform for cancer therapy.

Antitussive, expectorant, and bronchodilating effects of quinazoline alkaloids (±)-vasicine, deoxyvasicine, and (±)-vasicinone from aerial parts of Peganum harmala L.

BACKGROUND: The aerial parts of Peganum harmala L. (APP) is a well-known and effective herbal medicine in China, and has been commonly used for treating various ailments, including cough and asthma. OBJECTIVES: To evaluate the antitussive, expectorant, and bronchodilating effects of the quinazoline alkaloids (±)-vasicine (VAS), deoxyvasicine (DVAS) (both isolated from the alkaloid fraction of APP) and (±)-vasicinone (VAO) (synthesized from VAS). METHODS: The three quinazoline alkaloids were tested as antitussive on cough models in mice and guinea pigs. VAO was synthesized from VAS via the oxidation of hydrogen peroxide. VAS, VAO, and DVAS were orally administered at dosages of 5, 15, and 45 mg/kg. Cough in these models was induced by ammonia, capsaicin, and citric acid. Phenol red secretion experiments in mice were performed to evaluate the expectorant activity of the alkaloids. Bronchodilating effects were evaluated by using a bronchoconstrictive induced by acetylcholine chloride and histamine in guinea pigs. RESULTS: In antitussive tests, VAS, VAO, and DVAS significantly inhibited coughing frequency and prolonged the cough latency period in animals. At the highest doses tested (45 mg/kg), they showed antitussive activities similar to codeine phosphate (30 mg/kg) in mice and guinea pigs. Expectorant evaluation showed that VAS, VAO, and DVAS could significantly increase phenol red secretion in mice by 0.54-, 0.79- and 0.97-fold, by 0.60-, 0.99-, and 1.06-fold, and by 0.46-, 0.73-, and 0.96-fold, respectively, at dosages of 5, 15, and 45 mg/kg compared with the control (0.5% CMC-Na, 20 ml/kg). Ammonium chloride at 1500 mg/kg increased phenol red secretion in mice by 0.97-fold compared with the control. Bronchodilation tests showed that VAS, VAO, and DVAS prolonged the pre-convulsive time for 28.59%, 57.21%, and 29.66%, respectively, at a dose of 45 mg/kg in guinea pigs, whereas aminophylline prolonged the pre-convulsive time by 46.98% compared with pretreatment. CONCLUSIONS: Quinazoline alkaloids VAS, VAO, and DVAS have significant antitussive, expectorant, and bronchodilating activities. VAS, VAO, and DVAS are the active ingredients in APP, which can be used to treat respiratory disease.

Synthesis of nanostructured methotrexate/hydroxyapatite: Morphology control, growth mechanism, and bioassay explore.

In this study, a new structure of methotrexate/hydroxyapatite (MTX/HAp) nanorods via a facile hydrothermal route was reported. The as-synthesized samples were then characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric (TG) and differential scanning calorimetry (DSC) analysis. In order to explore the formation mechanism, the effects of reaction time, MTX concentrations and addition of ethylene glycol (PEG) were emphatically examined. The results indicated that, with the increase in reaction time, the fibrous nanoparticles turned to needle-like and then to rod-like. Our study also proved that reaction time of 12h was enough for the full-growth of the nanostructure. Drug-loading capacities (AIn) rose dramatically in the first 12h and reached a plateau afterwards. Importantly, MTX played a critical role in the longitudinal growth of MTX/HAp nanostructure and polyethylene glyco (PEG) was a good dispersing agent to improve the monodispersity. As expected, the functional agent of MTX was served as both the target anticancer drug loaded in HAp and effective complex agents to modify and control the morphologies of MTX/HAp. Lastly, in vitro bioassay tests gave us evidence that obvious tumor inhibition can be achieved when MTX was hybridized with HAp.

Methotrexate intercalated layered double hydroxides with the mediation of surfactants: Mechanism exploration and bioassay study.

Methotrexatum intercalated layered double hydroxides (MTX/LDHs) hybrids were synthesized by the co-precipitation method and three kinds of nonionic surfactants with different hydrocarbon chain lengths were used. The resulting hybrids were then characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). XRD and FTIR investigations manifest the successful intercalation of MTX anions into the interlayer of LDHs. TEM graphs indicate that the morphology of the hybrids changes with the variation of the chain length of the surfactants, i.e., the particles synthesized using polyethylene glycol (PEG-7) present regular disc morphology with good monodispersity, while samples with the mediation of alkyl polyglycoside (APG-14) are heavily aggregated and samples with the addition of polyvinylpyrrolidone (PVP-10) exhibit irregular branches. Furthermore, the release and bioassay experiments show that monodisperse MTX/LDHs present good controlled-release and are more efficient in the suppression of the tumor cells.

Methotrexatum intercalated layered double hydroxides: statistical design, mechanism explore and bioassay study.

A series of methotrexatum intercalated layered double hydroxide (MTX/LDH for short) hybrids have been synthesized by a mechanochemical-hydrothermal method, the statistical experiments are planned and conducted to find out the critical factor influencing the physicochemical properties. Four variables, i.e., addition of NaOH solution, grinding duration, hydrothermal temperature and time, are chosen to play as the examined factors in the orthogonal design. Furthermore, three respective levels, i.e., high, medium and low levels, are conducted in the design. The resulting hybrids are then characterized by X-ray diffraction (XRD) patterns, transmission electron microscope (TEM) graphs and Zeta potentials. XRD diffractions indicate that MTX anions have been successfully intercalated into LDH interlayers and the amount of NaOH solution can change the gallery height greatly. The information from TEM graphs and Zeta potentials state that the increase of alkali solution gives rise to regular morphology and the increase of Zeta potentials. As a result of the statistical analysis, addition of alkali solution is the major factor affecting the morphology and drug-loading capacity. At last, the mechanism of particle growth is explored emphatically, and the anticancer efficacy of some MTX/LDH hybrids is estimated by MTT assay on A549 cells as well.