Monodispersed MnxZn1-xFe2O4 magnetic nanoparticles of 8 nm are synthesized and encapsulated in amphiphilic block copolymer for development of the hydrophilic magnetic nanoclusters (MNCs). These MNCs exhibit superparamagnetic characteristics, high specific absorption rate (SAR), large saturation magnetization (Ms), excellent stability, and good biocompatibility. MnFe2O4 and Mn0.6Zn0.4Fe2O4 are selected as optimum compositions for the MNCs (MnFe2O4/MNC and Mn0.6Zn0.4Fe2O4/MNC) and employed for magnetic fluid hyperthermia (MFH) in vitro. To ensure biosafety of MFH, the parameters of alternating magnetic field (AMF) and exposure time are optimized with low frequency, f, and strength of applied magnetic field, Happlied. Under optimized conditions, MFH of MnFe2O4/MNC and Mn0.6Zn0.4Fe2O4/MNC result in cancer cell death rate up to 90% within 15 min. The pathway of cancer cell death is identified as apoptosis, which occurs in mild hyperthermia near 43 °C. Both MnFe2O4/MNC and Mn0.6Zn0.4Fe2O4/MNC show similar efficiencies on drug-sensitive and drug-resistant cancer cells. On the basis of these findings, those MnxZn1-xFe2O4 nanoclusters can serve as a promising candidate for effective targeting, diagnosis, and therapy of cancers. The multimodal cancer treatment is also possible as amphiphilic block copolymer can encapsulate, in a similar fashion, different nanoparticles, hydrophobic drugs, and other functional molecules.

Low-dose corticosteroids may provide a favorable benefit/risk ratio for many therapeutic applications. However, the extremely low plasma drug concentrations achieved, in conjunction with the insufficient sensitivity/ selectivity of current analytical methods, renders the evaluation of corticosteroid pharmacokinetics (PK) a significant challenge under such conditions. Furthermore, targeted therapeutic strategies involving administration by inhalation or intraocular injection could result in very low but sustained systemic corticosteroid concentrations, which must be quantified to determine potential side effects. Here we describe a robust method for the ultrasensitive quantification of corticosteroids in plasma samples. This was achieved by the combination of a selective solid-phase extraction (SPE) with a highly sensitive capillary LC (microLC)-MS/MS analysis. SPE washing and elution conditions were optimized so that target drugs are selectively extracted from plasma. By eliminating most undesirable compounds from the sample matrix, this selective SPE procedure enabled a high sample loading volume on the microLC column without compromising chromatographic performance and operational robustness and helped to achieve ultralow detection limits for the corticosteroids in plasma. The effect of microLC separation on the signal-to-noise ratio of corticosteroid peaks in plasma samples was investigated. It was found that with sufficient microLC separation, sensitivity was improved because of a decrease in matrix effects and the removal of endogenous interferences. Detection limits of four clinically important corticosteroids (budesonide, dexamethasone, triamcinolone acetonide, and dexamethasone acetate) ranged from 0.2 to 1 pg/mL in plasma, and linearity was good for all drugs in the range of 5-5000 pg/mL. Accuracy was 88-107% and the variation (CV%) was 2.3-11.1%. A limit of quantification (LOQ) of 5 pg/mL was validated for all four compounds. We applied this method to quantify the low levels of triamcinolone acetonide (TACA) in porcine plasma following suprachoroidal administration, which is necessary to estimate systemic drug exposure resulting from this novel clinical approach for treating inflammatory diseases of the eye. TACA in plasma could be quantified at low pg/mL levels for up to 90 days posttreatment. To our knowledge, this is the first practical analytical approach that can monitor plasma corticosteroids after intraocular administration, given the ultralow plasma concentrations achieved. In summary, this strategy enables PK analysis of corticosteroids in treatment regimens that result in extremely low systemic concentrations, and the approach can be extended for the sensitive quantification of other drugs.

Retained placenta (RP), defined as fetal membranes not being expelled within 24 h after calving, is a costly disease in multiparous dairy cows that has been linked to immune suppression, infections, elevated lipid mobilization, and depleted status of antioxidants including α-tocopherol, and that increases the risk of other diseases (OD) in early lactation. Early detection of cows at increased risk of developing RP, OD, or both in early lactation could improve treatment success and result in improved milk production and reproductive performance. To identify risk indicators of RP, OD, or both, we used a nested case-control design and compared multiparous dairy cows that developed RP (n=32) with cows that remained healthy (H; n=32) or cows that developed OD (n=32) in early lactation. We compared peripartal body condition score (BCS) as well as serum concentrations of α-tocopherol, metabolites [β-hydroxybutyrate (BHBA), cholesterol, glucose, nonesterified fatty acids (NEFA), and urea N], haptoglobin, and macrominerals (i.e., calcium, magnesium, and phosphorus) on d -21, -14, -7, -3, -1, 0, 1, 3, 7, 14, 21, 28, 35, 42, and 49 postpartum. In addition, average serum concentrations were calculated for each cow for the last 3 wk prepartum, for 3 and 2 wk prepartum combined, for the last week prepartum, and for the morning after calving and compared between groups. The RP cows had lower BCS than the H or OD cows until 2 wk postpartum. During the prepartal periods, RP and OD cows had lower α-tocopherol concentrations (corrected or not for cholesterol concentration) and higher NEFA and BHBA concentrations than H cows. Thus, lower prepartal BCS could be an early predictor for RP risk, and lower α-tocopherol concentrations and higher NEFA and BHBA concentrations could be early predictors for disease.

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Magnetothermally responsive drug-loaded micelles were designed and prepared for cancer therapy. These specially designed micelles are composed of the thermo-responsive star-block copolymer poly(ε-caprolactone)-block-poly(2-(2-methoxyethoxy)ethyl methacrylate-co-oligo(ethylene glycol)methacrylate) and Mn, Zn doped ferrite magnetic nanoparticles (MZF-MNPs). The thermo-responses of 6sPCL-b-P(MEO2MA-co-OEGMA) copolymers were shown to be dependent on the MEO2MA to OEGMA ratio. The lower critical solution temperature (LCST) of the star-block copolymers was controlled at 43 °C by adjusting the feed molar ratios of MEO2MA/OEGMA at 92 : 8. With the anti-tumor drug doxorubicin (DOX) self-assembling into the carrier system, the thermo-responsive micelles exhibited excellent temperature-triggered drug release behavior. In vitro cytotoxicity results showed high biocompatibility of the polymer micelles. Efficient cellular proliferation inhibition by the drug-loaded micelles was found on the HepG2 cells under different treatments. The thermo-responsive polymer micelles are promising for controlled drug delivery in tumor therapy under an alternating magnetic field.

This study aimed to investigate the effect of circ_0000950/miR-103 network on regulating neuron apoptosis, neurite outgrowth and inflammation in Alzheimer's disease (AD). Cellular AD model of rat pheochromocytoma cell line PC12 cells and cellular AD model of rat cerebral cortex neurons were constructed, and the effect of circ_0000950 on apoptosis, neurite outgrowth and inflammation in both cellular AD models was determined through upregulation and knockdown of circ_0000950 expression by transfection. Compensation experiments and luciferase assay were further performed to validate the sponging effect of circ_0000950 on miR-103 as well as the mechanisms of circ_0000950/miR-103 on regulating apoptosis, neurite outgrowth and inflammation in both cellular AD models. Circ_0000950 reduced miR-103 expression and increased prostaglandin-endoperoxide synthase 2 (PTGS2) expression in both two cellular AD models. And circ_0000950 overexpression promoted neuron apoptosis, suppressed neurite outgrowth and elevated IL-1β, IL-6 and TNF-α levels compared with overexpression control, whereas circ_0000950 knockdown inhibited neuron apoptosis, enhanced neurite outgrowth and lowered IL-1β, IL-6 and TNF-α levels compared with shRNA control in both two cellular AD models. Compensation experiments along with luciferase reporter assay validated that circ_0000950 promoted cell apoptosis, suppressed neurite outgrowth and elevated inflammatory cytokines levels via directly sponging miR-103. In conclusion, circ_0000950 promotes neuron apoptosis, suppresses neurite outgrowth and elevates inflammatory cytokines levels through directly sponging miR-103 in AD.

The magnetocaloric effects and lower critical solution temperature (LCST) were investigated in a magnetothermally-responsive nanocarrier for magnetothermal drug release under alternating magnetic field (AMF). The Mn(0.2)Zn(0.8)Fe(2)O(4) nanoparticles with low T(c) were dispersed in a polymeric matrix consisting of N-Isopropyl acrylamide (NIPAAm) and N-hydroxymethyl acrylamide (HMAAm). The magnetocaloric effects and LCST of the nanocarriers were characterized by using high-resolution electron transmission microscopy, thermogravimetric analyses, and vibrating sample magnetometer. The maximum self-heating temperature of 42.9 °C was achieved by optimizing the Mn(0.2)Zn(0.8)Fe(2)O(4) concentration in the polymer matrix. By adjusting the NIPAAm to HMAAm ratio, the LCST was controlled at an ideal level of 40.1 °C for efficient thermosensitive drug delivery. Magnetothermally responsive drug release of Doxorubicin, an anticancer drug, was significantly enhanced by application of an external AMF on the nanocarriers. The cytotoxicity experimental results in vitro show good biocompatibility and efficient therapeutic effects in cancer treatment.

BackgroundThe uteruses of most dairy cattle are easily infected by bacteria, especially gram-negative bacteria, following parturition. Macrophages are important cells of the immune system and play a critical role in the inflammatory response. In addition, cortisol levels become significantly increased due to the stress of parturition in dairy cattle, and cortisol is among the most widely used and effective therapies for many inflammatory diseases. In this study, we assessed the anti-inflammatory effects and potential molecular mechanisms of cortisol using a Lipopolysaccharide (LPS)-induced RAW264.7 macrophage cell line.ResultsCortisol significantly suppressed the production of prostaglandin E2 (PGE2) and decreased the gene and protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose-dependent manner. Moreover, cortisol inhibited the mRNA expression of pro-inflammatory cytokines including tumor necrosis factor alpha (TNFα), interleukin-1β (IL-1β), and interleukin-6 (IL-6) and decreased IL-1β secretion in an LPS-treated RAW264.7 macrophage cell line. Moreover, we found that cortisol suppressed nuclear factor-kappa B (NF-κB) signaling in RAW264.7 macrophages stimulated with LPS. This suppression was mediated by the inhibition of IκBα degradation and NF-κB p65 phosphorylation. In addition, cortisol also suppressed the phosphorylation of mitogen-activated protein kinases (MAPK) such as extracellular signal-regulated kinase (ERK1/2), p38 MAPK, and c-Jun N-terminal kinase/stress-activated protein kinase (JNK).ConclusionsThese results suggest that high cortisol levels can attenuate LPS-induced inflammatory responses in the RAW264.7 macrophage cell line by regulating the NF-κB and MAPK signaling pathways.