OBJECTIVE To investigate the absorption characteristics and tissue distribution of silybin （Sy） nanocrystals prepared by two methods in different intestinal segments of rats. METHODS Sy nanocrystals （i.e. Sy-NS-G and Sy-NS-F） with comparable particle sizes were prepared using high-pressure homogenization and anti-solvent precipitation methods， respectively. Rats were randomly divided into three groups： Sy raw drug group， Sy-NS-G group， and Sy-NS-F group. Each group was further divided into three subgroups with low， medium， and high （60， 120， 180 μg/mL） mass concentrations （calculated based on Sy）， with 3 rats in each subgroup. The absorption rate constant （Ka） and apparent absorption coefficient （Papp） of Sy raw drug， Sy-NS-G and Sy-NS-F in different intestinal segments were investigated by using the in vivo one-way intestinal perfusion experiment. Additionally， the rats were divided into three groups: Sy raw drug group， Sy-NS-G group， and Sy-NS-F group， with 20 rats in each group. Rats in each group were administered a single intragastric dose of 50 mg/kg （calculated based on Sy）. They were sacrificed at 0.3， 1， 4， 10， and 24 hours post-administration respectively， to investigate the tissue distribution of Sy raw drug， Sy- NS-G， and Sy-NS-F in the heart， liver， spleen， lungs， kidneys， brain and intestines. RESULTS In duodenum and jejunum， the Ka and Papp of the nanocrystals prepared by the two methods remained unchanged with the increase of Sy concentration， and there was no significant difference （P＞0.05）； the absorption of Sy-NS-F in the duodenum was greater than that of Sy-NS-G； the absorption sites of Sy-NS-G and Sy raw drug were mainly in the ileum， while those of Sy-NS-F were mainly in the duodenum and ileum. The concentrations of Sy-NS-G and Sy-NS-F in different tissues of rats were different； Sy-NS-G peaked in most tissues at 1 h， and the distribution concentration was as follows： intestine＞spleen＞heart＞lungs＞liver≈brain＞kidneys. Sy-NS-F reached its peak at 1 h， and the distribution concentration was in the order of intestine＞spleen＞kidney＞lung＞heart≈liver＞brain. CONCLUSIONS The absorption mode of Sy nanocrystals in the duodenum and ileum is mainly passive diffusion. In the duodenum， the absorption of Sy-NS-F is greater than that of Sy-NS-G； there are significant differences in the tissue distribution of Sy-NS-G and Sy-NS-F in rats.

OBJECTIVE To explore in vitro dissolution and in vivo pharmacokinetics of Luteolin solid dispersion in Beagle dogs. METHODS The dissolution of Luteolin solid dispersion was investigated according to the second method （paddle method） of the “dissolution determination method” in the 2020 edition of Chinese Pharmacopoeia （Part Ⅳ）. UPLC-MS/MS method was established to determine the concentration of luteolin in the plasma of Beagle dogs. Twelve Beagle dogs were randomly divided into luteolin group and Luteolin solid dispersion group， with 6 dogs in each group. They were given relevant medicine orally at the dose of 10 mg/kg luteolin. Blood was collected before medication （0 h）， at 5， 10， 15， 30， 45 min and 1， 2， 4， 6， 8， 10， 12， 24， 48 h after administration. After protein precipitation with acetonitrile， the blood concentration of luteolin in Beagle dogs was determined by UPLC-MS/MS and the major pharmacokinetic parameters were calculated with non-compartmental models by using DAS 3.2.8 pharmacokinetic software. RESULTS The dissolutions of Luteolin solid dispersion in purified water and 0.1% sodium dodecyl sulfate solution was significantly higher than those of luteolin； the dissolution rate reached 95% in 0.1% sodium dodecyl sulfate solution for 120 minutes. The peak concentration （cmax） of luteolin in the Luteolin solid dispersion group of Beagle dogs was 5.62 times higher than the luteolin group， and the relative bioavailability was 348%. Compared with luteolin group， cmax and the area under the drug time curve of luteolin in the Luteolin solid dispersion group of Beagle dogs were significantly increased， while the apparent distribution volume was significantly reduced （P＜0.05）. CONCLUSIONS Luteolin solid dispersion can improve in vitro dissolution and bioavailability of luteolin in Beagle dogs.

Objective To study the effect of storage duration on compressive mechanical properties of rabbit patellar, so as to provide references for in vitro ligament storage.Methods The compressive mechanical properties of rabbit patellar ligament storaged at -20 ℃ at different storage durations (in 36 d) were tested with the universal tensile test machine. The microscopic morphology of collagen fibers was observed under the scanning electron microscopy (SEM). The enthalpy and denaturation temperature of collagen fibers were measured with differential scanning calorimetry (DSC).Results With the increase of storage duration, the compressive stress of the patellar ligament at 40% strain increased from 19 kPa to 112 kPa and then decreased to 57 kPa. SEM observation showed that the cross-linking of collagen fibers was initially strengthened and then weakened. DSC results showed that the enthalpy increased from 59.47 J/g to 67.10 J/g and then decreased to 54.43 J/g. The denaturation temperature increased from 67.62 ℃ to 77.28 ℃ and then decreased to 64.10 ℃.Conclusions When rabbit patellar ligament is stored at -20 ℃, with the increase of storage duration, the compressive stress of rabbit patellar ligament at 40% strain increases at first and then decreases. This change may be due to the variation of cross-linking level of collagen fibers. The stronger the cross-linking of collagen fibers, the stronger the compressive mechanical properties will be.

Objective To explore the feasibility of the application of yak pericardium as anti-calcified heart valve materials in transcatheter aortic valve replacement (TAVR). Cattle pericardium and commercial Sino products were used as controls. Methods Yak and cattle pericardium was decellularized, and then the acellular extent was qualitatively and quantitatively analyzed with hematoxylin-eosin (HE) staining and DNA detection kit respectively. Two cross-linking agents, i.e. glutaraldehyde and genipin, were used to cross-link the acellular pericardium, respectively. After testing the mechanical property, thermodynamic stability and biocompatibility of the pericardium, the cross-linked pericardium was subcutaneously implanted in juvenile Wistar rats. After 2～4 weeks of the implantation, histological staining and tissue calcification analysis were conducted. Results The nuclei of the yak pericardium were almost invisible after decellularized treatment, and the DNA content decreased from (0.90±0.13)μg/mg to (0.09± 0.02)μg/mg that was significantly lower than that of Sino product (P<0.001). The mechanical strength of the acellular yak pericardium, glutaraldehyde or genipin cross-linked yak pericardium was higher than that of the cattle pericardium (all P<0.05). The maximum stress value, obtained in the glutaraldehyde cross-linked yak pericardium, was (8.44±2.61) MPa, which was higher than (7.92±1.81) MPa of the Sino product (P<0.05). The shrinkage temperature of non- and cross-linked yak pericardium was slightly higher than that of cattle pericardium, but difference was not statistically significant (all P>0.05). For the two cross-linked yak pericardium, the hemolysis rate and cell proliferation ratio was similar with that of cattle pericardium (all P>0.05), the tissue regeneration ability of subcutaneous implantations was inferior, and the calcification level was higher than that of cattle pericardium with an no statistically significant difference (all P>0.05). After 4 weeks of the subcutaneously implantation, the calcium content of the glutaraldehyde cross-linked pericardium was 32.62～65.49μg/mg. Conclusions Yak pericardium has better mechanical properties and thermodynamic stability than cattle pericardium, and the biocompatibility can meet the requirements of transcatheter aortic valve replacement.

Objective To investigate the protective effect of carbon monoxide release molecule-2 (CORM-2) on intestinal barrier injury in shock rats. Methods Thirty-two rats were equally and randomly divided into 4 groups: the sham operated group, shock group, carbon monoxide releasing molecule-2 (CORM-2) group and inactivated CORM-2 (iCORM-2) group. A modified Wiggers model was used in inducing hemorrhagic shock. In the CORM-2 group and iCORM-2 group, the animals were intraperitoneally injected CORM-2 (5 mg/kg) or iCORM-2 (5 mg/kg) 1 h before inducing shock. The ileum tissues were harvested 24 h after operation or 24 h after inducing shock, and the histopathologic changes and ultrastructure of the ileum were observed. The expressions of ZO-1, Occludin, and Claudin3 protein in ileum intestinal mucosa were determined by Western blot. TNF-α and D-lactic acid levels in the blood were measured by enzyme-linked immunosorbent assay (ELISA). Data of multi-groups were analyzed by one way variance (ANOVA) and inter-group comparisons were made by the least significant difference (LSD)-t tests. Kruskal Wallis rank sum test was used when homogeneity of variance were not met. The value of P<0.05 was considered statistically significant. Results (1) The pathological changes and ultrastructural damage of ileum mucosa in the shock group were obvious. CORM-2 can significantly improve the pathological morphology and ultrastructural integrity of intestinal mucosa in shock rats. (2) Compared with the sham operated group, the expressions of Claudin3, Occludin, and ZO-1 of ileum intestinal mucosa were significantly decreased in the shock group and iCORM-2 group(all P<0.05), but in the CORM-2 group, only the expression of Claudin3 and ZO-1 were decreased(P<0.05). The expression of these proteins in the CORM-2 group was higher than that in the shock group and iCORM-2 group. (3) Compared with the sham operated group, the levels of D-lactic acid and TNF-α in the shock group and iCORM-2 group were significantly higher[D-lactic acid(ng/mL): 139.49 ± 28.83, 135.75 ± 25.19 vs 65.09 ± 33.16; TNF-α(pg/mL):358.60(314.18, 395.73),312.25(275.75, 345.40) vs 65.85(47.82, 84.32); all P<0.05], TNF-α value and D-lactic acid level showed increased trend in CORM-2 group, but it's not statistically significant[ D-lactic acid(ng/mL): 75.65±34.14 vs 65.09±33.16; TNF-α(pg/mL): 104.00(93.10, 131.95) vs 65.85(47.82, 84.32); all P>0.05]. The levels of D-lactic acid and TNF-αin the CORM-2 group were lower than those in the shock group and iCORM-2 group (all P<0.05). Conclusions CORM-2 may reduce the intestinal barrier damage by anti-inflammatory effects and up-regulate the expression of tight junction proteins in the intestinal epithelium.

OBJECTIVE： To prepare insoluble anti-tumor drug-loading polymer micelles， and to increase inhibitive effect of insoluble anti-tumor drug. METHODS： Chitosan （CSO） and stearic acid （SA） were used to prepare blank micelles （CSO-SA）， then modified with mPEG and folic acid （FA） to prepare PEG-CSO-SA and FA-PEG-CSO-SA. Characteristic functional groups of CSO-SA， PEG-CSO-SA and FA-PEG-CSO-SA were detected by infrared spectroscopy. The morphology of micelles was observed by transmission electron microscopy. The particle size and Zeta potential of micelles were measured by laser particle size analyzer. Osthole （OST） was used as the model drug and drug-loading micelles （FA-PEG-CSO-SA/OST） were prepared by dialysis. MTT assay was used to detect the inhibitory rate of FA-PEG-CSO-SA， OST solution and FA-PEG-CSO-SA/OST to human liver cancer cell HepG2. Half inhibitory concentration （IC50） was calculated. RESULTS： FA-PEG-CSO-SA was successfully prepared. CSO-SA， PEG-CSO-SA， FA-PEG-CSO-SA were oval in shape； particle sizes were （96.01±5.99）， （112.93±1.06）， （216.01±4.76） nm （n＝3） and Zeta potentials were （39.30±1.75）， （38.03±2.91）， （15.17±2.10） mV （n＝3）， respectively. Encapsulation efficiency and drug-loading amount of OST in FA-PEG-CSO-SA were （84.47±2.07）％ and （16.01±0.90）％ （n＝3）， respectively. The inhibition rates of FA-PEG-CSO-SA to HepG2 cells were＜20％. IC50 of OST solution and FA-PEG-CSO-SA/OST to HepG2 cells were （62.08±5.21）， （27.49±0.50） μg/mL （n＝3）， respectively. CONCLUSIONS： Prepared FA-PEG-CSO-SA can significantly increase inhibitive effect of insoluble drug OST to HepG2 cells， and it is expected to become a new anti-tumor drug carrier.

OBJECTIVE:To prepare Baicalin monolithic osmotic pump tablets and investigate its in vitro drug release behavior. METHODS:Using accumulative release rate as evaluation index,baicalin solid dispersion was prepared to improve solubility,sin-gle factor test and orthogonal test were used to optimize preparation technology(the amount of penetrating agent and pore-forming agent,weight gaining of coating film) of monolithic osmotic pump tablets using baicalin solid dispersion as intermediate. Release rate and mechanism of samples prepared by optimized technology were investigated in 3 kinds of release medium (water,0.1 mol/L HCl,simulated gastric fluid). RESULTS:The optimal preparation technology was that penetrating agent sodium chloride was 30 mg;pore-forming agent polyethylene glycol 400 was 20% amount of excipient cellulose acetate;weight gaining of coating film was 2%. RSD of 12 h accumulative release rate was 1.06%(n=3)for 3 batches of Baicalin monolithic osmotic pump tablets pre-pared by optimized technology. 12 h accumulative release rate of them in 3 kinds of medium were similar to each other,being all more than 80%. Release equation was in line with zero-order drug release model (r=0.9985). CONCLUSIONS:Prepared Ba-icalin monolithic osmotic pump tablets after optimization can release drug at controlled rate.

OBJECTIVE:To develop a method for simultaneous determination of geniposide,baicalin,aloe-emodin,rhein, emodin,chrysophanol and physcion in Zhizi jinhua dispersible tablets. METHODS:HPLC method was adopted. The determination was performed on Dimonsil C18 column with mobile phase consisted of methanol-0.05%phosphoric acid(gradient elution)at the flow rate of 0.8 mL/min. The detection wavelength was set at 254 nm,and the column temperature was 25℃. The sample size was 20 μL. RESULTS:The linear ranges of geniposide,baicalin,aloe-emodin,rhein,emodin,chrysophanol and physcion were 0.0323-0.323 μg (r=0.9998),0.1374-1.374μg(r=0.9999),0.00372-0.0372μg(r=0.9997),0.0069-0.069μg(r=0.9995),0.00332-0.0332μg (r=0.9997),0.00864-0.0864 μg(r=0.9997) and 0.00122-0.0122 μg(r=0.9995),respectively. The limits of quantitation were 0.0321,0.1374,0.00372,0.0067,0.00330,0.00864,0.00122 μg,respectively. The limits of detection were 0.0095, 0.0041,0.0012,0.0020,0.0010,0.0026,0.0003 μg,respectively. RSDs of precision,stability and reproducibility tests were all lower than 3%. The average recoveries were 96.54%-99.52%(RSD=1.17%,n=6),97.23%-101.23%(RSD=1.36%,n=6), 97.22%-101.25%(RSD=1.83%,n=6),97.32%-100.23%(RSD=1.09%,n=6),97.99%-102.71%(RSD=1.73%,n=6), 96.99%-100.23%(RSD=1.21%,n=6),96.99%-103.01%(RSD=2.31%,n=6),respectively. CONCLUSIONS:The methods is simple and reproducible. It can be used for the content determination of 7 components in Zhizi jinhua dispersible tablets.

Objective To investigate the diagnostic value and characteristics of breast lesion in digital breast tomosynthesis (DBT) in combination with synthesized two-dimensional (2D) images. Methods The prospective study enrolled women older than 18 years with clinically suspected breast lesion.One hundred and sixty seven patients with 177 lesions confirmed by biopsy or surgery were included. All the patients underwent full-field digital mammography(FFDM)and DBT examinations,and synthesized 2D images(V-preview)were reconstructed from DBT.The images of FFDM,V-preview images and DBT plus FFDM, V-preview images were analyzed. The breast imaging reporting and data system (BI-RADS) and characteristic for predicting benign and malignant lesion were also evaluated.The average glandular dose for a single mammographic view between FFDM and DBT was recorded.The Nonparametric Z test was used to compare the differences among four different mammographic images in BI-RADS.The differential diagnostic performance among different mammography was evaluated by ROC analysis.Independent t test was used to compare the average glandular dose between FFDM and DBT.Results One hundred three benign lesions and 74 malignant lesions were confirmed. Compared with FFDM images alone or plus DBT,the diagnostic values of V-preview images alone/or plus DBT were not significantly different(Z=0.187 and 0.226,P=0.851 and 0.821), but compared with V-preview, the diagnostic values of V-preview images plus DBT revealed significant difference(Z=3.546,P<0.01).The area under ROC for V-preview plus DBT were 0.899,and the sensitivity,specificity,and accuracy were 90.5%,89.3%,and 89.3%,separately.For the average glandular dose, there was no significant difference between FFDM (1.48 ± 0.52) mGy and DBT (1.56 ± 0.39) mGy examination(t=1.714,P=0.087).Conclusion Synthesized 2D images from DBT,which may eliminate the need for FFDM,in combination with DBT can improve the diagnostic efficiency.

Objective To explore the effects of surface functionalized multi-walled carbon nanotubes (FMWCNTs) on the cytotoxicity of human peripheral blood mononuclear cell (PBMC).Methods Five different types of MWCNTs (hydroxylated,carboxylated,aminated,nickel-plated and pristine MWCNTs (P-MWCNTs)) with the same diameter and length were evaluated the dispersion and characterizations in physiological salt solution by transmission electron microscopy.PBMC were isolated by density gradient centrifugation from human peripheral blood,and 5 types of MWCNTs were ultrasonically dispersed in serum-containing medium respectively.After incubation with PBMC for 12,24,48 or 72 h,cytotoxicity was detected by CCK-8 kits.Results All the MWCNTs had well dispersion,especially the F-MWCNTs.Cytotoxicity results showed that all types of MWCNTs could induced PBMC death,and presented dose-dependence manner and a certain degree of time-dependence manner.Compared with the P-MWCNTs,F-MWCNTs changed cytotoxicity statistically,with the hydroxylated,carboxylated,aminated MWCNTs weakened,aminated MWCNTs significant (P＜0.05),nevertheless the nickel-plated MWCNTs increased.Compared with the P-MWCNTs (25 μg/ml),cell viability of PBMC after 24 and 48 h incubation with the same dose of nickelplated MWCNTs both decreased,and the differences was statistically significant (P＜0.01,P＜0.05).Conclusions The functional group modification affects not only the MWCNTs dispersion in medium,but also the cytotoxicity of the MWCNTs on PBMC.