808 nm photocontrolled UCL imaging guided chemo/photothermal synergistic therapy with single UCNPs-CuS@PAA nanocomposite

Recently, incorporating multiple components into one nanostructured matrix to construct a multifunctional nanomedical platform has attracted more and more attention for simultaneous anticancer diagnosis and therapy.

Controllable drug release system based on phase change molecules as gatekeepers for bimodal tumor therapy with enhanced efficacy

NIR- and pH-triggered DOX release in Cu₉S₅@mSiO₂-PEG@DOX@TD multifunctional drug delivery.

DNA-Hybrid-Gated Photothermal Mesoporous Silica Nanoparticles for NIR-Responsive and Aptamer-Targeted Drug Delivery

Near-infrared light is an attractive stimulus due to its noninvasive and deep tissue penetration. Particularly, NIR light is utilized for cancer thermotherapy and on-demand release of drugs by the disruption of the delivery carriers. Here we have prepared a novel NIR-responsive DNA-hybrid-gated nanocarrier based on mesoporous silica-coated Cu1.8S nanoparticles. Cu1.8S nanoparticles, possessing high photothermal conversion efficiency under a 980 nm laser, were chosen as photothermal agents. The mesoporous silica structure could be used for drug storage/delivery and modified with aptamer-modified GC-rich DNA-helix as gatekeepers, drug vectors, and targeting ligand. Simultaneously, the as-produced photothermal effect caused denaturation of DNA double strands, which triggered the drug release of the DNA-helix-loaded hydrophilic drug doxorubicin and mesopore-loaded hydrophobic drug curcumin, resulting in a synergistic therapeutic effect. The Cu1.8S@mSiO2 nanocomposites endocytosed by cancer cells through the aptamer-mediated mode are able to generate rational release of doxorubicin/curcumin under NIR irradiation, strongly enhancing the synergistic growth-inhibitory effect of curcumin against doxorubicin in MCF-7 cells, which is associated with a strong mitochondrial-mediated cell apoptosis progression. The underlying mechanism of apoptosis showed a strong synergistic inhibitory effect both on the expression of Bcl-2, Bcl-xL, Mcl-1, and upregulated caspase 3/9 activity and on the expression level of Bak and Bax. Therefore, Cu1.8S@mSiO2 with efficient synergistic therapeutic efficiency is a potential multifunctional cancer therapy nanoplatform.

No influence of CYP2D6*10 genotype and phenotype on the pharmacokinetics of nebivolol in healthy Chinese subjects

WHAT IS KNOWN AND OBJECTIVE

Nebivolol, a clinically important antihypertensive drug, mainly metabolized by cytochrome P450 (CYP) 2D6, shows wide interindividual variability in pharmacokinetics. The CYP2D6*10 allele (100C>T; rs1065852), present at a high frequency in the Chinese population, is associated with alteration in the pharmacokinetics of many drugs, but its effect on the pharmacokinetics of nebivolol is unknown. The aim of our study was to investigate whether the CYP2D6*10 genotype and phenotype are associated with changes in the pharmacokinetics of nebivolol in Chinese subjects.

METHODS

Twenty-four healthy subjects were divided into three groups according to CYP2D6*1/*1 (n = 7), CYP2D6*1/*10 (n = 5) and CYP2D6*10/*10 (n = 12) genotypes. The *1/*1 homozygotes and *1/*10 heterozygotes were C allele carriers. All subjects received oral single dose of nebivolol and dextromethorphan. Blood and urine samples were gathered at various times.

RESULTS

There were no statistically significant differences in the pharmacokinetics of nebivolol between the three CYP2D6*10 genotypes, and no gene-dose effect was seen. The pharmacokinetic parameters of CYP2D6*10/*10 subjects were also similar to those of CYP2D6*1 carriers. A weak relationship between CYP2D6 phenotype and nebivolol clearance was found.

WHAT IS NEW AND CONCLUSION

The CYP2D6*10 genotype and phenotype were not associated with significant alterations in the pharmacokinetics of nebivolol. CYP2D6*10 alone does not account for the large interindividual differences observed in the disposition of nebivolol among Chinese healthy subjects.

Effect of oleic acid supplementation on prostaglandin production in maternal endometrial and fetal allantochorion cells isolated from late gestation ewes

INTRODUCTION

Elevated circulating non-esterified fatty acids including oleic acid (OA) are associated with many pregnancy related complications. Prostaglandins (PGs) play crucial roles during parturition. We investigated the effect of OA supplementation on PG production using an in vitro model of ovine placenta.

METHODS

Maternal endometrium (ME) and fetal allantochorion (FC) were collected in late pregnancy (day 135). Confluent cells were cultured in serum-free medium supplemented with 0, 20 or 100 μM OA and challenged with control medium, oxytocin (OT, 250 nM), lipopolysaccharide (LPS, 0.1 μg/ml) or dexamethasone (DEX, 5 μM). Spent medium was harvested at 2 and 24 h after challenge for quantifying PGs.

RESULTS

In ME cells OA increased PGE2 production moderately but attenuated PGF2α production leading to a doubling of the PGE2:PGF2α ratio (E:F) (P < 0.01). Without OA, both OT and LPS stimulated PG production for about 3-fold (P < 0.01) without changing the E:F ratio. In the ME cells challenged with OT, OA decreased both PGE2 and PGF2α production by up to 70% (P < 0.01) whereas in LPS treated cells OA increased the E:F ratio. In FC cells PGE2 production at 2 h was stimulated by 100 μM OA (P < 0.05). In these cells LPS caused a 3-fold increase in PGE2 (P < 0.01), an effect which was completely inhibited by DEX.

DISCUSSION

OA supplementation favours basal PGE2 production in both ME and FC. In ME OA increased E:F ratios and antagonized the stimulatory effect of OT on PG production. This suggests that raised circulating OA may affect both the initiation and progression of parturition.

Caesarean Sections in Beijing, China - Results from a Descriptive Study

OBJECTIVE

Caesarean section rates are increasing dramatically in China. The predominant contributor to the increase in China was the unnecessary Caesarean section. The objective of this study was to estimate the excess economic burden caused by unnecessary Caesarean sections vs. vaginal delivery for Beijing and all China.

METHODS

The 33 476 obstetric medical case files from randomly selected 17 hospitals of Beijing in 2011 were taken for our descriptive approach. Based on the individual medical files and on a definition of what necessary and unnecessary Caesarean sections are, we sampled also the data for costs and length of stay for comparisons with vaginal deliveries. The Mann-Whitney U test and Pearson chi-square test statistics were used to test for significant difference in the analysis.

RESULTS

The Caesarean section rate was 58.5% among all deliveries and that rate of unnecessary Caesarean sections was 71.5% among all the Caesarean sections but 41.8% among all deliveries in Beijing. The hospitalisation expenses of unnecessary Caesarean sections were 472 US$ higher than that of a vaginal delivery on average. The total excess economic burden caused by unnecessary Caesarean sections can be estimated to 38.97 million US$ for Beijing and to 3.29 billion US$ all over China in 2011. This is equivalent to the annual health expenditure of over 139 575 residents in Beijing and of 11 783 120 residents in China, respectively.

CONCLUSION

Socio-economic factors are possible reasons for the increase of unnecessary Caesarean section in China and more analytical attention should be paid to that problem in order to propose fitting practical reactions.

UV-emitting upconversion-based TiO2 photosensitizing nanoplatform: near-infrared light mediated in vivo photodynamic therapy via mitochondria-involved apoptosis pathway

Photodynamic therapy (PDT) is a promising antitumor treatment that is based on the photosensitizers that inhibit cancer cells by yielding reactive oxygen species (ROS) after irradiation of light with specific wavelengths. As a potential photosensitizer, titanium dioxide (TiO2) exhibits minimal dark cytotoxicity and excellent ultraviolet (UV) light triggered cytotoxicity, but is challenged by the limited tissue penetration of UV light. Herein, a novel near-infrared (NIR) light activated photosensitizer for PDT based on TiO2-coated upconversion nanoparticle (UCNP) core/shell nanocomposites (UCNPs@TiO2 NCs) is designed. NaYF4:Yb(3+),Tm(3+)@NaGdF4:Yb(3+) core/shell UCNPs can efficiently convert NIR light to UV emission that matches well with the absorption of TiO2 shells. The UCNPs@TiO2 NCs endocytosed by cancer cells are able to generate intracellular ROS under NIR irradiation, decreasing the mitochondrial membrane potential to release cytochrome c into the cytosol and then activating caspase 3 to induce cancer cell apoptosis. NIR light triggered PDT of tumor-bearing mice with UCNPs@TiO2 as photosensitizers can suppress tumor growth efficiently due to the better tissue penetration than UV irradiation. On the basis of the evidence of in vitro and in vivo results, UCNPs@TiO2 NCs could serve as an effective photosensitizer for NIR light mediated PDT in antitumor therapy.

Multifunctional hollow CaF2:Yb(3+)/Er(3+)/Mn(2+)-poly(2-Aminoethyl methacrylate) microspheres for Pt(IV) pro-drug delivery and tri-modal imaging

Combining the multi-modal medical imaging with cancer therapy in one single system has attracted the great interests for theranostic purpose. In this paper, CaF2:Yb(3+)/Er(3+)/Mn(2+)-poly(2-Aminoethyl methacrylate) (UCHNs-PAMA) hybrid microspheres were successfully fabricated. The synthetic route to the nanocomposite based on a facile hydrothermal method for fabrication of hollow upconversion (UC) nanospheres at first and then post-filling the PAMA interiorly through photo-initiated polymerization. The UCHNs showed orange fluorescence under 980 nm near infrared (NIR) laser excitation, which provided the upconverting luminescence (UCL) imaging modality. Meanwhile, the presence of functional Mn(2+) and Yb(3+) offered the enhanced T1-weighted magnetic resonance (MR) and computed tomography (CT) imaging, respectively. Thanks to introducing amine groups-containing PAMA inside the hollow nanospheres, the Pt(IV) pro-drug, c,c,t-Pt(NH3)2Cl2(OOCCH2CH2COOH)2 (DSP), can be conveniently bonded on the polymer network to construct a nanoscale anti-cancer drug carrier. The UCHNs-PAMA-Pt(IV) nanocomposite shows effective inhibition for Hela cell line via MTT assay. In contrast, Pt(IV) pro-drug and UCHNs-PAMA microspheres behave little cytotoxicity to Hela cells. This should be attributed the fact that the anti-cancer ability can be recovered only when Pt(IV) pro-drug was reduced to Pt(II)-drug in cellular environment. Furthermore, the in vivo experiments on small mice also confirm that the hybrid microspheres have relatively low toxic side effects and high tumor inhibition rate. These findings show that the multifunctional hybrid microspheres have potential to be used as UCL/MR/CT tri-modal imaging contrast agent and anti-cancer drug carriers.

Aptamer-mediated up-conversion core/MOF shell nanocomposites for targeted drug delivery and cell imaging

Multifunctional nanocarriers for targeted bioimaging and drug delivery have attracted much attention in early diagnosis and therapy of cancer. In this work, we develop a novel aptamer-guided nanocarrier based on the mesoporous metal-organic framework (MOF) shell and up-conversion luminescent NaYF4:Yb(3+)/Er(3+) nanoparticles (UCNPs) core for the first time to achieve these goals. These UCNPs, chosen as optical labels in biological assays and medical imaging, could emit strong green emission under 980 nm laser. The MOF structure based on iron (III) carboxylate materials [MIL-100 (Fe)] possesses high porosity and non-toxicity, which is of great value as nanocarriers for drug storage/delivery. As a unique nanoplatform, the hybrid inorganic-organic drug delivery vehicles show great promising for simultaneous targeted labeling and therapy of cancer cells.

Multifunctional polyelectrolyte multilayers coated onto Gd2O3:Yb3+,Er3+@MSNs can be used as drug carriers and imaging agents

Multifunctional polyelectrolyte multilayers coated Gd₂O₃:Yb³⁺,Er³⁺@MSNs were fabricated as potential drug delivery system with MRI, UCL, and pH-responsive release properties.

Current advances in lanthanide ion (Ln3+)-based upconversion nanomaterials for drug delivery

This review mainly focuses on the recent advances in various chemical syntheses of Ln³⁺-based upconversion nanomaterials, with special emphasis on their application in stimuli-response controlled drug release and subsequent therapy.

A cheap and facile route to synthesize monodisperse magnetic nanocrystals and their application as MRI agents

Monodisperse MnFe₂O₄ and CoFe₂O₄ nanocrystals (NCs) were synthesized by a facile thermal decomposition strategy, using very cheap polyisobutylene succimide and paraffin oil as a surfactant and solvent which was used as the effective T₂ contrast agent for MRI.

Efficient gene delivery and multimodal imaging by lanthanide-based upconversion nanoparticles

Nanoparticles have been explored as nonviral gene carriers for years because of the simplicity of surface modification and lack of immune response. Lanthanide-based upconversion nanoparticles (UCNPs) are becoming attractive candidates for biomedical applications in virtue of their unique optical properties and multimodality imaging ability. Here, we report a UCNPs-based structure with polyethylenimine coating for both efficient gene transfection and trimodality imaging. Cytotoxicity tests demonstrated that the nanoparticles exhibited significantly decreased cytotoxicity compared to polyethylenimine polymer. Further, in vitro studies revealed that the gene carriers are able to transfer the enhanced green fluorescence protein (EGFP) plasmid DNA into Hela cells in higher transfection efficiency than PEI. Gene silencing was also examined by delivering bcl-2 siRNA into Hela cells, resulting in significant downregulation of target bcl-2 mRNA. More importantly, we demonstrated the feasibility of upconversion gene carriers to serve as effective contrast agents for MRI/CT/UCL trimodality imaging both in vitro and in vivo. The facile fabrication process, great biocompatibility, enhanced gene transfection efficiency, and great bioimaging ability can make it promising for application in gene therapy.

Progesterone-induced cyclin G1 inhibits the proliferation of endometrial epithelial cell and its possible molecular mechanism

Under normal conditions, progesterone inhi-bits the estrogen-induced proliferation of endometrial epithelium. Our previous studies have shown that cyclin G1 was progesterone-dependent in mouse endometrial epithelium at peri-implantation, and exogenous cyclin G1 suppressed the proliferation of endometrial cancer cells. The objectives of this study are to determine whether cyclin G1, as a negative regulator of the cell cycle, is involved in the antiproliferative action of progesterone on endometrial epithelial cells, and to explore the possible molecular mechanism of cyclin G1 inhibition. The siRNA-mediated elimination of cyclin G1 attenuated the antiproliferative action of progesterone on endometrial epithelial cells. Immunoprecipitation showed that progesterone-induced cyclin G1 could interact with PP2A to mediate its phosphatase activity. The block of PP2A activity also attenuated the antiproliferative action of progesterone on endometrial epithelial cells and increased the phosphorylated Rb. In conclusion, progesterone-induced cyclin G1 mediates the inhibitory effect of progesterone on endometrial epithelial cell proliferation possibly through the recruitment of PP2A to dephosphorylate Rb.