Functionalized Caprolactone-Polyethylene Glycol Based Thermo-Responsive Hydrogels of Silibinin for the Treatment of Malignant Melanoma.

PURPOSE: Silibinin, is a natural compound, which has shown anticancer activity in various malignancies. In this study, we evaluated the anticancer effects of silibinin in B16-F10 melanoma cells and developed a novel thermoresponsive hydrogel for local delivery of this compound. METHOD: A thermoresponsive hydrogel loaded with silibinin was prepared using triblock copolymers of poly[(α-benzyl carboxylate-e-caprolactone)-co-(α-carboxyl-e-caprolactone)]ran-b-PEG-b-[(α-benzyl carboxylate-e-caprolactone) -co-(α-carboxyl-e-caprolactone)]ran (PCBCL-b-PEG-b-PCBCL), namely PolyGelTM, and compared with a Pluronic F-127 formulation of silibinin. Sol-gel transition temperature of hydrogels was measured by inverse flow method and modulated differential scanning calorimetry (MDSC). Silibinin loading efficiency was measured by HPLC. The MTT and clonogenic assays were used to assess the cytotoxicity and anti-proliferative effects of silibinin on B16-F10 melanoma cells. Flow cytotmetry was used to quantify the induced level of apoptosis and measure the intracellular level of activated STAT3 (pSTAT3) following silibinin treatment in B16.F10 cells. The effects of silibinin on the activation of oncogenic proteins were also evaluated by western blot. RESULTS: Silibinin inhibited cell proliferation (IC50 = 67 µM), provoked cell cycle arrest, induced apoptosis, suppressed key oncogenic pathways (i.e STAT3 and MEK/ERK), and enhanced the cytotoxic effects of doxorubicin in B16-F10 cells. Both PolyGelTM and Pluronic F-127 hydrogels were effective in loading silibinin. A lower drug release pattern within 24h, fitting first- order release kinetics, was observed for the release of silibinin from both gels compared to free drug.  PolyGelTM demonstrated enhanced percutaneous absorption of silibinin through increasing mouse skin intracellular lipid fluidity as documented by DSC of skin following PolyGelTM use. Silibinin loaded in PolyGel TM inhibited the growth of B16-F10 cells (IC50 = 30 µM) and effectively suppressed pSTAT3 activity in B16-F10 cells at 10 µM. CONCLUSION: Our results imply a great potential for PolyGel TM formulations of silibinin for local treatment of malignant melanoma. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's content page.

Microfabricated thermal conductivity sensor: a high resolution tool for quantitative thermal property measurement of biomaterials and solutions.

Obtaining accurate thermal properties of biomaterials plays an important role in the field of cryobiology. Currently, thermal needle, which is constructed by enclosing a manually winded thin metal wire with an insulation coating in a metallic sheath, is the only available device that is capable of measuring thermal conductivity of biomaterials. Major drawbacks, such as macroscale sensor size, lack of versatile format to accommodate samples with various shapes and sizes, neglected effects of heat transfer inside the probe and thermal contact resistance between the sensing element and the probe body, difficult to mass produce, poor data repeatability and reliability and labor-intense sensor calibration, have significantly reduced their potential to be an essential measurement tool to provide key thermal property information of biological specimens. In this study, we describe the development of an approach to measure thermal conductivity of liquids and soft bio-tissues using a proof-of-concept MEMS based thermal probe. By employing a microfabricated closely-packed gold wire to function as the heater and the thermistor, the presented thermal sensor can be used to measure thermal conductivities of fluids and natural soft biomaterials (particularly, the sensor may be directly inserted into soft tissues in living animal/plant bodies or into tissues isolated from the animal/plant bodies), where other more standard approaches cannot be used. Thermal standard materials have been used to calibrate two randomly selected thermal probes at room temperature. Variation between the obtained system calibration constants is less than 10%. By incorporating the previously obtained system calibration constant, three randomly selected thermal probes have been successfully utilized to measure the thermal conductivities of various solutions and tissue samples under different temperatures. Overall, the measurements are in agreement with the recommended values (percentage error less than 5%). The microfabricated thermal conductivity sensor offers superior characteristics compared to those traditional macroscopic thermal sensors, such as, (a) reduced thermal mass and thermal resistivity, (b) improved thermal contact between sensor and sample, (c) easy to manufacture with mass production capability, (d) flexibility to reconfigure sensor geometries for measuring samples with various sizes and shapes, and (e) reduced calibration workload for all sensors microfabricated from the same batch. The MEMS based thermal conductivity sensor is a promising approach to overcome the inherent limitations of existing macroscopic devices and capable of delivering accurate thermal conductivity measurement of biomaterials with various shapes and sizes.

[Comparative study on three kinds of microtube extraction devices in vitro].

OBJECTIVE: This study aims to compare the efficiency of three kinds of microtube extraction devices, namely, instrument removal system (IRS), micro-retrieve and repair (MR&R) system, and MR&R system using modified microtube in removing separated instruments with different exposure lengths. METHODS: After a cross-section platform model was established, the IRS, MR&R, and MR&R modified microtube system with sidewall window reduced to 0.20 mm were used to retrieve various separated instrument models, and the differences in extraction effects were statistically analyzed by Chi-square test. The separated instrument models were divided into two groups: stainless steel and nickel-titanium instrument groups. In total, 23 instruments were tested for three times each. RESULTS: When the exposed length of separated instrument was 0.50 mm, the removal efficiency of the modified MR&R system group was significantly higher than those of the IRS and MR&R system groups (P<0.001). When the broken end of the fracture instrument was up to 1.00 mm, the success rates of the MR&R system and modified MR&R groups were significantly higher than that of the IRS group (P<0.01). No difference was observed among these three devices when the exposure length of separated instruments was 1.50 mm or higher. CONCLUSIONS: The MR&R and modified MR&R systems have good removal effect when the exposed length of separated instrument is small.

Development of a Uricase-Free Colorimetric Biosensor for Uric Acid Based on PPy-Coated Polyoxometalate-Encapsulated Fourfold Helical Metal-Organic Frameworks.

Developing a new cost-effective and reliable approach used for the detection of uric acid (UA) with no requirement of uricase is still very challenging. Herein, an easily realized, cost-effective, and uricase-free approach is reported for selective colorimetric biosensing of UA utilizing polypyrrole (PPy)-coated polyoxometalate-encapsulated fourfold helical metal-organic frameworks Ag5[bimt]2[PMo12O40]·2H2O (Ag5PMo12) as a monolithic peroxidase mimic. It is demonstrated that the as-obtained Ag5PMo12@PPy possesses excellent peroxidase-like activity originated from the synergistic effect to induce catalytic oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to green oxTMB in the presence of H2O2. Then, the green oxTMB can be selectively converted to colorless TMB induced by UA; thus, UA can inhibit the catalytic oxidation of TMB. Based on these results, a uricase-free colorimetric biosensor for UA is achieved with a linear detection range of 1-50 µM and a detection limit of 0.47 µM. More importantly, the developed biosensor is suited for simple-operated and good reliable UA detection in clinical samples, showing promising application ability in clinical diagnosis and relative fields.

Biosynthesis and characterization of 3-hydroxyalkanoate terpolyesters with adjustable properties by Aeromonas hydrophila.

Polyhydroxyalkanoates (PHA) terployesters P(3HB-co-3HV-co-3HHx) consisting of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 3-hydroxyhexanoate (3HHx) were produced by wild-type Aeromonas hydrophila 4AK4, its recombinant harboring PHA synthesis genes phaPCJ encoding PHA binding protein phasin, PHA synthase, and enoyl-CoA hydratase, and another its recombinant harboring phaAB encoding beta-ketothiolase and acetoacetyl-CoA reductase, respectively, when grown in lauric acid and/or valerate. The terpolyesters produced by A. hydrophila 4AK4 (phaAB) grown in velarate were found to produce copolymers P(3HB-co-3HV) containing high 3HV fractions with a maximum of 99 mol% 3HV. In terpolyesters, 3HV ranged from 9 to 32 mol% depending on the valerate concentration and strain used. A maximal terpolyester P(3HB-co-3HV-co-3HHx) content in dry cells was 71 wt%. Transmission electron microscopy study of A. hydrophila 4AK4 harboring phaPCJ revealed the full occupation of terpolyester P(3HB-co-3HV-co-HHx) in the cellular spaces. Terpolyesters with various monomer compositions showed changing thermal and mechanical properties. Those with higher 3HV fractions demonstrated an improved property over the lower HV containing ones.

[Study on DNA methylation profiles in non-syndromic cleft lip/palate based on bioinformatics].

PURPOSE: To study DNA methylation patterns of non-syndromic cleft lip/palate(NSCL/P) using bioinformatic methods, including methylated positions and regions. METHODS: Whole blood DNA methylation data of NSCL/P samples was download from Gene Expression Omnibus(GEO) database, including 67 NSCL/P cases and 59 controls without birth defects. Data analysis included ①data cleaning, such as probes filtering, quality control and normalization; ②differential methylation analysis, including methylated positions and regions; ③Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis on differential methylated genes. R 3.4.3 software was used for data cleaning, differential methylated positions and regions analysis. DAVID6.8 tool was used for GO and KEGG analysis. RESULTS: 814 differential methylated positions were detected (adjusted P＜0.001，|Δß|＞0.125）, of which 178 were hypermethylated in NSCL/P patients, and 636 were hypomethylated. In addition, 386 differential methylated regions were identified (P＜0.05), of which 204 were hypermethylation regions and 182 were hypomethylation regions. GO analysis showed that 38 differential methylated genes were involved in 7 kinds of biological processes, 163 differential methylated genes were involved in 3 kinds of molecular functions, and 114 differential methylated genes were involved in 3 kinds of cellular components (P＜0.01). KEGG analysis showed that 59 differential methylated genes were involved in 9 kinds of signal pathways. CONCLUSIONS: Abnormal DNA methylation patterns of NSCL/P might be an important epigenetic mechanism affecting the development of NSCL/P. This study might contribute to the identification of identification of biomarkers and targeted interventions of NSCL/P.

[Oxidative stress and susceptibility of periodontal disease].

PURPOSE: To investigate the relationship between dietary antioxidant status and susceptibility of periodontal disease in humans. METHODS: Fifty patients with moderate-to-sever periodontal disease and 50 subjects without periodontal disease were enrolled in this study. Food frequency questionnaire and 72-hour diet recall were conducted to study the dietary pattern and antioxidant nutrients intake in patients and healthy subjects. Nutritional status including vitamins, mineral substance, and antioxidant enzymes in these 2 groups were analyzed in serum and saliva samples by liquid chromatography-mass spectrometry (LC-MS). SPSS 19.0 software package was used for paired t test. RESULTS: Compared with the control group, the chronic periodontal group had lower levels of potatoes, aquatic product, milk, soy, fresh vegetables, fruit and vitamin supplements intake(P<0.05). Through food components analysis we found that the intake of vitamin A, C, B2, E, calcium, magnesium, copper, selenium was significantly lower in the chronic periodontal disease group than that in the control group (P<0.05). Biochemical analysis demonstrated that antioxidant nutrient levels including antioxidant enzyme SOD in serum and saliva together with magnesium, calcium, manganese, zinc in saliva were significantly lower in disease periodontal group than in the control group (P<0.05). CONCLUSIONS: Oxidative stress plays an essential role in the occurrence and development of periodontal disease. The antioxidant nutrients may help to protect paradentium. Supported by Research Fund from Shanghai Municipal Health Bureau (20114103).

[The relationship between dietary factors and susceptibility of periodontal disease].

PURPOSE: A clinical survey was made on the life style and dietary behaviors of people with non-periodontal disease and people with periodontal disease for prevention and treatment of periodontal diseases. METHODS: 72-hour diet analysis and frequency analysis of dietary intake were performed in 60 patients with moderate-to-severe periodontal disease and 60 patients with healthy periodontal tissues randomly selected in the Ninth People's Hospital for dental treatment. The data was analyzed by Student's t test and Chi-square test with SPSS13.0 software package. RESULTS: There was significant difference (P<0.05) in vitamin C, flavonoids and ß-carotene dietary intake between control group and periodontal disease group; In periodontal disease group, dietary intake of selenium and zinc intake was different from the normal control, but the difference was not statistically significant (P>0.05). CONCLUSIONS: There is a close relationship between oral health and antioxidant nutrients. Lower dietary vitamin C content, flavonoid content and ß-carotene intake lead to destruction of periodontal tissue and higher incidence of periodontal disease.

[Effects of soluble microbial product on the performance of submerged membrane bioreactor].

The behaviors of soluble microbial products (SMP) and SMP effects on an operational process of submerged membrane bioreactor (SMBR) were studied. Within 90 days performance period, total organic carbon (TOC), molecular weight distributions (MWDs), specific oxygen uptake rate (SOUR)were periodically monitored. The dead-end filtration tests were used to indicate the SMP effect on membrane fouling. Experiment results showed that the concentration of SMP in SMBR supernatant obviously accumulated. As the operation time was prolonged, the concentrations of SMP with MW > 10,000 remarkably increased in SMBR supernatant. Compared with the SMP of MW < 1,000, the SMP with MW > 10,000 obviously affected sludge activity and membrane fouling, but did not significantly influence the SMBR effluent.

[Effect of aeration intensity on the filterability of mixed liquor in membrane bioreactor].

The influence of aeration intensity on membrane fouling in membrane bioreactors (MBR) was to investigate. Two lab-scale MBR with aeration intensity of 500 and 100 L/h were operated for 60 days at a constant permeate flux. The dead-end filtration tests were conducted to confirm the mixed sludge filterability under each condition. The effect of aeration intensity on relative molecular mass distributions of SMP, the particle size distributions (PSD) of flocs and the quantity of extracellular polymeric substances (EPS) in MBRs were also tested. The results show that large aeration intensity has a negative influence on the filterability of mixed sludge in MBR. Further research finds that the large aeration intensity results in the increase of soluble microbial products (SMP) with a relative molecular mass (M(r)) > 10 000 in supernatant, which obviously affects the filtration of mixed sludge. It is also found that small particles in the range of 1-10 microm and the concentration of EPS in flocs remarkably increase under high aeration intensity of 500 L/h.

[Comparison of sludge filtration characteristics between a membrane bioreactor and a conventional activated sludge process].

According to the filtration characteristics of sludge, a comparison between a membrane bioreactor (MBR) and a conventional activated sludge process(CAS) was carried out under similar conditions. Experiment results show that the filtration resistance in MBR was 2 to approximately 3 times of that in CAS. The contribution of supernatant resistance to filtration resistance was about 90% both in CAS and in MBR. The test on resistance distribution showed the cake resistance made up 87.30% and 94.18% of total resistance in CAS and MBR, respectively.