In vivo safety assessment, biodistribution and toxicology of polyvinyl alcohol microneedles with 160-day uninterruptedly applications in mice.

Dissolving microneedles (DMNs) are widely used in drug delivery systems since they are based on one-step application, which is simple and convenient for patients, especially for the patients such as diabetes who need daily or long-term self-administration. In general, the matrix materials of DMNs are water-soluble materials that can release the encapsulated drugs gradually by dissolving in the skin without generating sharp needle waste. However, the matrix materials of DMNs will also leave in the skin after application. Thus, it is vital to evaluate whether the matrix material of DMNs dissolved in the skin will cause health risks such as toxicity to the body or some skin-related complications to patients who frequent or long-term administration. In this work, PVA, as one of the typical matrix materials of DMNs, was selected to prepare the DMNs to research the safety of PVA-based MNs to the body after being dissolved in the skin. Briefly, in a 160 - days trial, the healthy mice were daily administrated by PVA MNs. The results showed that PVA materials mainly accumulated in the skin tissues of mice after dissolving and the concentration of PVA in the insertion sites gradually decreased and was almost undetectable at 6 days after administration. The observation of general conditions, blood hematological analysis and histological examinations of the mice demonstrated that the PVA-based MNs do not cause appreciable toxicity to the healthy mice after daily insertion in a 160 - days trial. Altogether, these results encourage further studies of PVA MNs for biomedical applications and support translation of PVA-based DMNs from pre-clinical development into clinical trials.

The relationship between demands for lung cancer screening and the constructs of health belief model: a cross-sectional survey in Hefei, China.

The aim of investigation is to explore the relationship between demands for lung cancer screening (LCS) and the constructs derived from the health belief model (HBM) in Hefei. The study collected data about socio-demographics, health beliefs in and demands for LCS during early June to later July 2015. By constructing a LCS demands HBM constructs, it calculated indices of demands for LCS (DSI) and HBM constructs, which include perceived risk (PR) and seriousness (PS) of the cancers; and perceived effectiveness (PE), benefits (PB) and difficulties (PD) of the screening. It also performed descriptive and multivariate regression analysis of the demands and the HBM constructs. The amount of 823 respondents participated and completed the survey. 6.4% of them had ever undertaken LCS, whereas 60.1% of them expressed willingness to accept the service of LCS if it is free. In multiple regression analysis which used weights in calculating the HBM construct indices, education displayed significant positive associations with DSI (p = .044), and most of HBM constructs indices (PSI, PRI, PBI, and PDI) were statistically significant with DSI (p < .05). HBM-based constructs regarding LCS have important effects on demands for the service, and may provide effective paths to cancer screening promotion.

In vitro and in vivo assessment of polymer microneedles for controlled transdermal drug delivery.

Microneedles (MNs) system for transdermal drug delivery has the potential to improve therapeutic efficacy, proving an approach that is more convenient and acceptable than traditional medication systems. This study systematically researched dissolving polymer MNs fabricated from various common FDA-approved biocompatible materials, including gelatine, chitosan, hyaluronic acid (HA) and polyvinyl alcohol (PVA). Upon application of MN patches to the porcine cadaver skin, the MNs effectively perforated the skin and delivered drugs to subcutaneous tissue on contact with the interstitial fluid. Both the in vitro and in vivo drug release tests showed the similar trends but different release rates among the prepared MNs. Interestingly, the drug-release kinetics of PVA MNs were able to be altered by changing the molecular weight. To evaluate the feasibility using the proposed MNs for treating diabetes, an in vivo insulin absorption study in diabetic mice was performed. The results showed different insulin release properties of MNs fabricated from various kinds of polymer, leading to different decrease in blood glucose levels. We made a systematic and comprehensive study of some drug-loaded polymer MNs, and anticipated that dissolving polymer MNs have potential to improve therapeutic efficacy through controlled drug release.

Spectral CT imaging as a new quantitative tool? Assessment of perfusion defects of pulmonary parenchyma in patients with lung cancer.

OBJECTIVE: This study investigated the capability of dual-energy spectral computed tomography (CT) to quantitatively evaluate lung perfusion defects that are induced by central lung cancer. METHODS: Thirty-two patients with central lung cancer underwent CT angiography using spectral imaging. A univariate general linear model was conducted to analyze the variance of iodine concentration/CT value with three factors of lung fields. A paired t-test was used to compare iodine concentrations and CT values between the distal end of lung cancer and the corresponding area in the contralateral normal lung. RESULTS: Iodine concentrations increased progressively in the far, intermediate and near ground sides in the normal lung fields at 0.60±0.28, 0.93±0.27 and 1.25±0.38 mg/mL, respectively (P<0.001). The same trend was observed for the CT values [-(840.64±49.08), -(812.66±50.85) and -(760.83±89.17) HU, P<0.001]. The iodine concentration (0.70±0.42 mg/mL) of the lung field in the distal end of lung cancer was significantly lower than the corresponding area in the contralateral normal lung (1.19±0.62 mg/mL) (t=-7.23, P<0.001). However, the CT value of lung field in the distal end of lung cancer was significantly higher than the corresponding area in the contralateral normal lung [-(765.29±93.34) HU vs. -(800.07±76.18) HU, t=3.564, P=0.001]. CONCLUSIONS: Spectral CT imaging based on the spectral differentiation of iodine is feasible and can quantitatively evaluate pulmonary perfusion and identify perfusion defects that are induced by central lung cancer. Spectral CT seems to be a promising technique for the simultaneous evaluation of both morphological and functional lung information.

[Immunotoxicologic assessment of genetically modified drought-resistant wheat T349 with GmDREB1].

OBJECTIVE: To assess the immunotoxicologic effects of genetically modified drought resistant wheat T349 with GmDREB1 gene. METHODS: A total of 250 female BALB/c mice (6-8 week-old, weight 18-22 g) were divided into five large groups (50 mice for each large group) by body weight randomly. In each large group, the mice were divided into five groups (10 mice for each group) by body weight randomly, which were set as negative control group, common wheat group, parental wheat group, genetically modified wheat group and cyclophosphamide positive control group, respectively. Mice in negative control and positive control group were fed with feedstuff AIN-93G, mice in common wheat group, non-genetically modified parental wheat group and genetically modified wheat group were fed with feedstuffs added corresponding wheat (proportion up to 76%) for 30 days, then body weight, organ coefficient of spleen and thymus, peripheral blood lymphocytes phenotyping, serum cytokine, serum immunoglobulin, antibody plaque-forming cell (PFC), serum 50% hemolytic value (HC50), mitogen-induced splenocyte proliferation, delayed-type hypersensitivity (DTH) reaction and phagocytic activities of phagocytes were detected respectively. RESULTS: After 30 days raise, among negative control group, common wheat group, non-genetically modified parental wheat group, genetically modified wheat group and cyclophosphamide positive control group, mice body weight were (21.0±0.3), (20.4±0.7), (21.1±1.0), (21.1±1.0), (19.4±1.0) g, respectively (F=7.47, P<0.01); organ coefficient of spleen were (0.407±0.047)%, (0.390±0.028)%, (0.402±0.042)%, (0.421±0.041)%, (0.304±0.048)%, respectively (F=12.41, P<0.01); organ coefficient of thymus were (0.234±0.032)%, (0.246±0.028)%, (0.249±0.040)%, (0.234±0.034)%, (0.185±0.039)%, respectively (F=5.58, P<0.01); the percentage of T cell in peripheral blood were (70.43±4.44)%, (68.33±5.37)%, (73.04±2.68)%, (74.42±2.86)%, (90.42±1.66)%, respectively (F=57.51, P<0.01); the percentage of B cell were (13.89±3.19)%, (15.34±4.84)%, (13.06±4.22)%, (12.93±2.36)%, (3.01±0.96)%, respectively (F=12.79, P<0.01); the percentage of Th cell were (55.87±3.80)%, (55.24±4.60)%, (57.92±3.70)%, (59.57±2.54)%, (77.37±2.31)%, respectively (F=68.58, P<0.01);the Th/Ts ratio were 4.16±0.29, 4.73±0.96, 4.19±0.78, 4.52±0.40, 6.34±0.73, respectively (F=17.57, P<0.01);the serum IgG were (1046.38±210.67), (1065.49±297.22), (1517.73±299.52), (1576.67±241.92), (1155.88±167.05) µg/ml, respectively (F=10.53, P<0.01); the serum IgM were (333.83±18.97), (327.73±27.72), (367.47±27.18), (363.42±46.14), (278.71±24.42) µg/ml, respectively (F=12.11, P<0.01); the serum IgA were (51.69±10.10), (42.40 ± 8.35), (32.11±4.22), (37.12±4.90), (41.45±8.89) µg/ml, respectively (F=8.25, P<0.01); the PFC were (29.2±14.6), (28.0±20.0), (34.8±30.9), (33.2±25.1), (4.8±5.3) per 10(6) splenocyte, respectively (F=3.33, P<0.05); the HC50 were 82.3±6.5, 79.7±4.6, 75.8±4.1, 74.9±3.6, 70.8±2.1, respectively (F=9.99, P<0.01);the LPS-induced splenocyte proliferation were 0.21±0.10, 0.21±0.14, 0.26±0.12, 0.25±0.14, 0.07±0.06, respectively (F=4.18, P<0.05). CONCLUSION: The genetically modified drought-resistant wheat T349 was substantially equivalent to parental wheat in the effects on immune organs and immunologic functions of mice, and it didn't show immunotoxicity.