Compared with conventional transdermal drug delivery systems, dissolving microneedles significantly enhance drug bioavailability by penetrating the stratum corneum barrier and achieving intradermal drug delivery. In order to improve the transdermal bioavailability of dexmedetomidine hydrochloride, in this study, a novel microneedle delivery system was developed for dexmedetomidine hydrochloride based on 3D printing combined with micro-molding. By systematically optimizing the microneedle geometrical parameters, array arrangement, and preparation process parameters, we determined the optimal ratio of drug-carrying matrix as 15% PVP (polyvinyl pyrrolidone) K90. The microneedles exhibited significant drug loading gradients, with mean content of (209.99±27.56) μg/patch, (405.31±30.31) μg/patch, and (621.61±34.43) μg/patch. They showed a regular pyramidal structure under SEM and handheld electron microscopy, and their mechanical strength allowed effective penetration into the stratum corneum. The surface contact angles were all < 90°, indicating excellent hydrophilicity. The microneedles dissolved completely within 10 min after skin insertion, achieving a cumulative release rate of 90% (Higuchi model, r=0.996) during 2 hours of in vitro transdermal permeation. The cytotoxicity test and hemolysis test verified good biocompatibility. Pharmacodynamic evaluation showed that the microneedle group demonstrated pain-relieving effect within 15 min, with the pain threshold at the time point of 60 min being 3 times that in the transdermal cream group. The microneedle system developed in this study not only offers an efficient drug delivery option for patients but also establishes an innovative platform for rapid percutaneous delivery of hydrophilic drugs, demonstrating significant potential in perioperative pain management.
Dexmedetomidine/pharmacokinetics* ; Printing, Three-Dimensional ; Needles ; Drug Delivery Systems/methods* ; Administration, Cutaneous ; Animals ; Microinjections/instrumentation* ; Skin Absorption ; Skin/metabolism*

OBJECTIVE To establish an ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method for determination of dexmedetomidine(DEX)in plasma of beagle dogs and evaluate the pharmacokinetics and sedation after nasal,buccal and sublingual mucosal admin-istration.METHODS A UPLC-MS/MS method was established and validated for dertermination of DEX in plasma of beagle dogs.DEX was administered to the nasal cavity,buccal and sublingual mucous membranes of beagle dogs,respectively.Blood samples were collected at different time points.The plasma concentration of DEX was measured by the established UPLC-MS/MS method.Pharmacokinetic parameters were fitted by Phoenix software and the sedative effect at different mucous membrane sites was evaluated in conjunction with behavioral and Ramsay scores.RESULTS The linearity of DEX was fine within the range of 0.05-100 μg·L-1(r>0.999),which was validated methodologically to meet the requirements of quantitative detection.The plasma concentration of the drug peaked the fastest with nasal administration.Tmax was 0.25 h,Cmax(4.43±1.19)μg·L-1,and the AUC0-6h was(8.92±2.07)μg·h·L-1,compared with 0.92 and 1 h,(2.87±0.69),(2.70±0.41)μg·L-1,and(7.99±1.77),(7.01±2.09)μg·h·L-1 with buccal and sublingual administration.Nasal administration had the fastest onset at 7 min,with a Ramsay score of 4,and sedation lasted for 36 min,compared with 33 and 35 min,and 38 and 37 min for buccal and sublingual administration.CONCLUSION The proposed method is sensitive,reliable and applicable to quantitative analysis of DEX in plasma of beagle dogs.Administration of DEX to the nasal cavity mucosa has a faster onset and a better sedative effect than to the buccal and sublingual mucosa.

OBJECTIVE To establish an ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method for determination of dexmedetomidine(DEX)in plasma of beagle dogs and evaluate the pharmacokinetics and sedation after nasal,buccal and sublingual mucosal admin-istration.METHODS A UPLC-MS/MS method was established and validated for dertermination of DEX in plasma of beagle dogs.DEX was administered to the nasal cavity,buccal and sublingual mucous membranes of beagle dogs,respectively.Blood samples were collected at different time points.The plasma concentration of DEX was measured by the established UPLC-MS/MS method.Pharmacokinetic parameters were fitted by Phoenix software and the sedative effect at different mucous membrane sites was evaluated in conjunction with behavioral and Ramsay scores.RESULTS The linearity of DEX was fine within the range of 0.05-100 μg·L-1(r>0.999),which was validated methodologically to meet the requirements of quantitative detection.The plasma concentration of the drug peaked the fastest with nasal administration.Tmax was 0.25 h,Cmax(4.43±1.19)μg·L-1,and the AUC0-6h was(8.92±2.07)μg·h·L-1,compared with 0.92 and 1 h,(2.87±0.69),(2.70±0.41)μg·L-1,and(7.99±1.77),(7.01±2.09)μg·h·L-1 with buccal and sublingual administration.Nasal administration had the fastest onset at 7 min,with a Ramsay score of 4,and sedation lasted for 36 min,compared with 33 and 35 min,and 38 and 37 min for buccal and sublingual administration.CONCLUSION The proposed method is sensitive,reliable and applicable to quantitative analysis of DEX in plasma of beagle dogs.Administration of DEX to the nasal cavity mucosa has a faster onset and a better sedative effect than to the buccal and sublingual mucosa.

Objective To investigate the value of extracellular volume fraction(ECV)based on CT for predicting macrotrabecular-massive hepatocellular carcinoma(MTM-HCC).Methods Data of 23 MTM-HCC(MTM-HCC group)and 56 non-MTM-HCC(nMTM-HCC group)patients were retrospectively analyzed,and CT manifestations were compared between groups.CT values of abdominal aorta(P-CTabdominal aorta,E-CTabdominal aorta),tumors(P-CTtumor,E-CTtumor)and non-tumor liver parenchyma(P-CTliver,E-CTliver)in plain phase(P)and enhancement equilibrium phase(E)CT were measured,then ECV of tumors and liver parenchyma were calculated,and ECV-related parameters were compared between groups.Receiver operating characteristic curves were drawn,and area under the curve(AUC)was calculated to evaluate the predictive efficacy of ECV-related parameters for predicting MTM-HCC.Results No significant difference of CT manifestations was found between groups(all P＞0.05).E-CTtumor,Δltumor(absolute enhancement CT value of the tumor area)and ECVtumor in MTM-HCC group were all lower than those in nMTM-HCC group(all P＜0.01).The AUC of E-CTtumor,Δtumor and ECVtumor for predicting MTM-HCC was 0.74,0.77 and 0.87,respectively,and the AUC of ECVtumor was higher than that of E-CTtumor and Δtumor(Z=2.271,2.557,P=0.023,0.011).Conclusion ECV based on CT could be used to effectively predict MTM-HCC.

Objective To investigate the correlation between amide proton transfer-weighted(APTw)value derived from APTw imaging and Ki-67 expression in hepatocellular carcinoma.Methods Sixty patients with hepatic occupations underwent preoperative upper abdominal MRI scanning,including APTw and diffusion weighted imaging(DWI)sequences.Thirty-two patients with hepatocellular carcinoma proved by pathological results were enrolled in the prospective study.The APTw and apparent diffusion coefficient(ADC)values of the lesions were measured from the corresponding APTw and ADC images,respectively.Mann-Whitney U test or independent sample t test was used to analyze the differences in APTw and ADC values between the high and low Ki-67 expression groups.Pearson correlation analysis was used to evaluate the correlation between APTw value,ADC value and Ki-67 expression level of hepatocellular carcinoma.The receiver operating characteristic(ROC)curve was used to evaluate the diagnostic efficacy of amide proton transfer(APT)parameter in differentiating high and low Ki-67 expression groups.Results The APTw values of high Ki-67 expression group(n=24)was higher than that of low Ki-67 expression group(n=8)[(1.33±0.77)％vs(0.64±0.58)％,P=0.026].There was no significant difference in ADC values between the two groups(0.82×10-3 mm2/s vs 0.86×10-3 mm2/s,P=0.679).The APTw values were positively correlated with Ki-67 expression(r=0.377,P=0.035),and the area under the curve(AUC)of APTw value＞1.24％for the diagnosis of high Ki-67 expression was 0.794,with a sensitivity of 67％and a specificity of 88％.Conclusion The APTw value of hepatocellular carcinoma is positively correlated with Ki-67 expression,which has certain diagnostic value for predicting the expression status of Ki-67.

Background::Sentinel lymph node (SLN) biopsy is gradually accepted as the standard of care in breast cancer patients with down-staged axillary disease after neoadjuvant chemotherapy (NAC). However, it is still difficult to precisely define pre-NAC clinical node-positive (cN1) and post-NAC clinical node-negative (ycN0). This prospective single-center trial was designed to evaluate the feasibility and accuracy of standard targeted axillary dissection (TAD) after NAC in highly selective pre-NAC cN1 patients (not considering ultrasound-based axillary ycN staging).Methods::This prospective trial included patients with initial pre-NAC cT1–3N1M0 invasive breast cancer but with a rigorous definition of cN1 from the Affiliated Cancer Hospital of Zhengzhou University. When NAC was effective (including complete and partial responses) and preoperative axillary palpation was negative, preoperative ultrasound-based axillary staging was not considered, and all patients underwent TAD followed by axillary lymph node (LN) dissection. The detection rate (DR) and false-negative rate (FNR) of TAD were calculated.Results::A total of 82 patients were included, and 77 of them were eligible for data analysis. The DR for TAD was 94.8% (73/77). There were 26 patients with one abnormal LN at the time of diagnosis based on ultrasound, 45 patients with two, and 2 patients with three. One patient had one TAD LN, four patients had two TAD LNs, and 68 patients had three or more TAD LNs. Preoperative axillary palpation yielded negative results for all 73 patients who successfully underwent TAD. Preoperative ultrasound-based ycN0 and ycN+ conditions were detected for 52 and 21 cases, respectively. The FNR was 7.4% (2/27) for standard TAD (≥3 SLNs), which was lower than that of all successful TAD (≥1 SLN; 10.0%, 3/30).Conclusions::In rigorously defined pre-NAC cN1 breast cancer patients, standard TAD is feasible for those with negative axillary palpation after NAC, and FNR is also less than 10%.Registration::chictr.org.cn, ChiCTR2100049093

Objective : To investigate the protective effect and related mechanisms of dexmedetomidine (Dex) on iron overload toxicity in mouse hippocampal neurons (HT22) induced by ferric ammonium citrate (FAC) . Methods: Selected HT22 cells in good condition were randomly divided into 4 groups: control group ( Ctrl group), FAC treatment group (FAC group), Dex treatment group (Dex group), ferroptosis inhibitor Fer⁃1 treatment group (Fer1 group) . The iron overload model was established by FAC⁃induced cells . Subsequently, the proliferation and survival rate of HT22 cells was detected by CCK⁃8 method; Western blot was used to detect the ferroptosis marker proteins prostaglandin⁃endoperoxide synthase 2 ( PTGS2 ) and acyl⁃CoA synthetase long⁃chain family member 4 (ACSL4) . The protein expressions of mammalian target of rapamycin ( mTOR), transferrin receptor 1 ( TFR1) and ferroportin (Fpn); the gene expression levels of PTGS2 and ACSL4 in HT22 cells were detected by qPCR; Reactive oxygen species (ROS) levels in HT22 cells was detected by DHE fluorescent probe; MDA detection kit was used to detect lipid oxidation levels in HT22 cells; Mito⁃FerroOrange—ferrous ion probe was used to detect ferrous ion levels in HT22 cells; electron microscopy was used to detect intracellular ultrastructural changes . Results: Dex group and Fer⁃1 group significantly decreased cell death rate after 2 h of pretreatment, the protein and gene expression levels of ferroptosis markers PTGS2 and ACSL4 significantly decreased . The degree of cell ultrastructural damage was significantly improved . The levels of ROS, lipid oxidation and Fe2 + were significantly lower than those of the FAC group (P < 0. 05) . Conclusion Dex pretreatment can attenuate FAC⁃induced iron overload toxicity in⁃ jury in HT22 cells, which may be related to the inhibition of ferroptosis .

Objective:To investigate the stability and feasibility of improved silent MRA technique based on hybrid-arterial spin labeling(ASL) for imaging intracranial arterial stenosis.Methods:From September 2019 to May 2020, totally 35 patients with suspected intracranial vascular stenosis in Department of Neurology of Northern Jiangsu People′s Hospital were enrolled in this study. Silent MRA and improved silent MRA based on hybrid-ASL technique were performed respectively. The acquisition noise (noise measurement and subjective score) of two kinds of MRA examination were evaluated respectively. Two neuroradiologists performed image quality scoring and signal-to-noise ratio (SNR) measurement of intracranial arteries (including internal carotid artery, vertebrobasilar artery, anterior cerebral artery, middle cerebral artery, and posterior cerebral artery) in the two kinds of MRA images using a double-blind, completely randomized method. Independent sample t-test was used to compare the image quality and SNR of two kinds of MRA images in each segment. Two experts assessed the degree of stenosis at the site of confirmed intracranial artery stenosis. Kappa test was used to assess interobserver and intermodel agreement. Results:There was no significant difference in acquisition noise between improved silent MRA and silent MRA ( P>0.05). In all five segments measured, the image quality scores of internal carotid artery [(4.40±0.49)scores], anterior cerebral artery[(4.30±0.33)scores] and middle cerebral artery [(4.46±0.34)scores] in improved silent MRA were higher than those in silent MRA images [(4.02±0.43)scores, (4.02±0.31)scores, (4.02±0.31)scores; t=2.825, 2.877, 1.683, all P<0.05)]. The SNR of internal carotid artery (9.11±1.23) and middle cerebral artery (8.77±1.87) in improved silent MRA images was higher than that in silent MRA images (7.83±1.33, 8.06±2.67, respectively; t=11.154, 3.268, both P<0.05). A total of 24 patients (38 lesions) with intracranial vascular stenosis were diagnosed by CTA. Improved silent MRA (Kappa=0.89, 95%CI 0.82-0.95) and silent MRA (Kappa=0.85, 95%CI 0.77-0.92) were highly consistent among observers in evaluating the degree of cerebrovascular stenosis.The results of improved silent MRA were highly consistent with those of CTA (Kappa=0.92, 95%CI 0.87-0.98), and those of silent MRA were highly consistent with those of CTA (Kappa=0.85, 95%CI 0.77-0.92). Conclusions:The improved silent MRA is feasible to improve the imaging quality and signal uniformity through efficient marking based on keeping the low noise features. In the diagnosis of intracranial stenosis and occlusive disease, the stability of improved silent MRA imaging improves the diagnostic efficiency of stenosis to a certain extent.

Objective: To investigate the expression of macrophage migration inhibitory factor (MIF) in pulmonary tissues from patients with chronic obstructive pulmonary disease (COPD) and the relationship with its clinical features. Methods: One hundred and eighty patients who underwent pulmonary bullectomy lobectomy due to pneumatocele from January 2015 to September 2018 in Longgang Central Hospital were enrolled and classified into patients without COPD (control group)and patients with COPD (COPD group), with 90 patients each group. According to the lung function parameters, 90 patients with COPD were divided into the mild COPD group, the moderate COPD group, and the severe COPD group. The levels of mRNA and protein of MIF were measured with RT-PCR, ELISA and Western blot. One-way ANOVA, Pearson correlation analysis and SNK-q test were used to analyze the results with SPSS 18.0, and P<0.05 was considered statistically significant. Results: The level of MIF in pulmonary tissues from the control group was obviously lower than those in the COPD group (P<0.05). The level of MIF in pulmonary tissues in the severe COPD group was obviously higher than those in pulmonary tissues in the mild COPD, moderate COPD and control groups (P<0.05). MIF was positively correlated with the lung function parameters (P<0.05). Conclusion The high expression of MIF in pulmonary tissues is closely related to the severity of COPD.

Objective To explore the value of single source dual energy CT for quantitative measurement of liver fat fraction in the rabbit model of nonalcoholic fatty liver disease(NAFLD).Methods Thirty male New Zealand rabbits were randomly divided into five groups.Six rabbits were fed with standard chow as a control group for 3 weeks.TwentyGfour rabbits were divided into four groups and fed with highGfat, highGcholesterol diet to reach different stage of NAFLD model for 1 ,3 ,4 and 8 weeks respectively before dualGenergy CT scanning.1 40 keV polychromatic CT values (QC),70 keV monochromatic CT values (Mono 70 keV),slope,effective atomic number (EffectiveGZ)and fat concentration based on dualGenergy CT fat decomposition (Fat/Water)were measured.Liver samples were obtained to measure the fat fraction and staged according to Burnt staging system.Correlations between different CT indexes and fat fraction were analyzed.ROC was used to evaluate the diagnosis efficacy of different parameters.Results Correlation between fat concentration based on dualGenergy CT fat decomposition and fat fraction (r＝0.936)was better than that between 140 keV polychromatic CT values (r＝－0.838)and 70 keV monochromatic CT values (r＝－0.906),as well as effective atomic number (r＝－0.858)and slope (r＝0.863).In terms of diagnostic performance of material decomposition fat imaging,the values of area under the curve were 0.944 (stage 0 vs.stage 1 or more severe),0.995 (stage 1 or less severe vs.stage 2 or more severe)and 1 (stage 2 or less severe vs.stage 3)with optimal cutoff values of 59.310,99.5 17 and 22 3.02 3 mg/cm3 ,respectively.Conclusion The dualGenergy CT can quantitatively measure liver fat concentration as a noninvasive surrogate bioGmarker in the rabbit model of nonalcoholic fatty liver disease.DualGenergy CT derived material decomposition fat images can provide more diagnostic information at the early stage of NAFLD.