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Efficient mucosal delivery remains a major challenge for the reason of the respiratory tract mucus act as a formidable barrier to nanocarriers by trapping and clearing foreign particulates. The surface property of nanoparticles determines their retention and penetration ability within the respiratory tract mucus. However, the interaction between nanoparticles and mucus, and how these interactions impact distribution has not been extensively investigated. In this study, polymeric nanoparticles loaded with a baicalein-phospholipid complex were modified with two kinds of polymers, mucoadhesive and mucus-penetrative polymer. Systematic investigations on the physicochemical property, mucus penetration, transepithelial transport, and tissue distribution were performed to evaluate the interaction of nanoparticles with the respiratory tract. Both nanoparticles had a similar particle size and good biocompatibility, exhibited a sustained-release profile, but showed a considerable difference in zeta potential. Interestingly, mucus-penetrative nanoparticles exhibited a higher diffusion rate in mucus, deeper penetration across the mucus layer, enhanced cellular uptake, increased drug distribution in airways, and superior local distribution and bioavailability as compared to mucoadhesive nanoparticles. These results indicate the potential of mucus-penetrative nanoparticles in design of a rational delivery system to improve the efficiency of inhaled therapy by promoting mucus penetration and increasing local distribution and bioavailability.
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Objective@#To develop the Chinese primipara social capital scale (C-PSCS), and to evaluate its validity and reliability.@*Methods@#The items of C-PSCS were developed based on Social Capital Scale by the World Bank and Social Network Scale. This scale was modified according to the characteristics of primiparas. We selected 10 experts who specialized in related field, and two rounds of seminars about content, cultural compatibility, primiparas' characteristics, and practicability. The finally C-PSCS included four dimensions: social trust, social reciprocity, social network, and social participation. Using purposive sampling to select 1 100 primiparas in their third trimesters (gestational weeks from 30 to 36 weeks). The validity analyses included content validity, construct validity and discriminant validity. The reliability analyses included Cronbach' α coefficient, and split-half reliability.@*Results@#1 035 questionnaires (94.09%) were qualified and the completion time was (13.23 ± 2.53) minutes. The total score of scale was 195.38 ± 45.98, and scores for social trust, social reciprocity, social network, and social participation were 30.26 ± 4.25, 22.84 ± 4.21, 34.23 ± 7.47, and 108.05 ± 41.96, respectively. The common factor cumulative variance contribution rates of each dimension were from 52.92% to 69.37%, which achieved more than 50% of the approved standard, and all the items held factor loading >0.5 in its relevant common factor, it had good construct validity. The scale had a good content validity, the r values between each dimensions and total scale were range from 0.57 to 0.81, P<0.01. For the high-score group, scores for social trust, social reciprocity, social network, and social participation dimensions were 32.89±3.19, 25.65±3.48, 38.27±6.59, 119.94±36.61, respectively, which were higher than low-score group (27.77±3.58, 20.18±2.91, 30.40±6.13, 96.76 ± 43.60), t-values were -24.23, -27.46, -19.90, and -9.24, respectively, P<0.001. It had good discriminant validity. The Cronbach'α coefficient for the total scale and four dimensions were from 0.76 to 0.86, and whose split-half reliability were from 0.68 to 0.84.@*Conclusion@#The validity and reliability of C-PSCS were excellent, and could be used to evaluate the social capital situation on the Chinese primiparas.
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OBJECTIVE:To establish a method for the separation and detection of related substances in baicalein,identify its structure and preliminarily explore the degradation mechanism. METHODS:HPLC was adopted to detect the baicalein,related impurities and forced destruction of degradation products in synthesis process:the column was ES Industries? FluoroSep-RP Phenyl with mobile phase of 0.3%formic acid-methanol-acetonitrile(gradient elution)at a flow rate of 1.0 mL/min,the detection wavelength was 275 nm,the column temperature was 10℃,and the injection volume was 10μL. LC-MS/MS was conducted to identify the related substances and conjecture degradation mechanism:the column was ES Industries? FluoroSep-RP Phenyl with mobile phase of 0.3%formic acid- methanol (gradient elution)at a flow rate of 1.0 mL/min,the detection wavelength was 275 nm,column temperature was 10℃,and the injection volume was 10μL;ion source was electrospray ion source,positive and negative ions,nebulizer pressure was 55 psi and the drying gas flow was 11 L/min,drying gas temperature was 350℃,capillary voltage was 4.0 kV,detection modes were full-scan first-order MS and selective ion full-scan second-order MS,scan ranges were m/z 100-1000 (first-order MS) and 50-500(second-order MS),ionization voltage was 80-135 eV,and the collision energy was 10-30 eV. RESULTS:The linear range of baicalein was 2.4-480μg/mL(r=0.9999);RSDs of precision,stability and reproducibility tests were lower than 2.0%;the limit of quantitation was 7.2 ng,the limit of detection was 2.4 ng. Baicalein was well separated with related substance and 3 major degradation products,the related substance was chemical synthesis precursor wood butterfly;the degradation products were 6,7-quinone derivatives and 7,8-quinone derivatives,which were isomers;oxidative degradation products were benzoic acid phenyl ester derivatives. CONCLUSIONS:The main mechanisms of alkali degradation and oxidative degradation of baicalein include pyran, reciprocal rearrangement and oxidation reaction;the established method is specific and sensitive,and can be used for the detection of related substances in baicalein.