OBJECTIVES: To investigate the effect of orexin-A-mediated regulation of ionotropic glutamate receptors for promoting motor function recovery in rats with spinal cord injury (SCI). METHODS: Thirty-six newborn SD rats (aged 7-14 days) were randomized into 6 groups (n=6), including a normal control group, a sham-operated group, and 4 SCI groups with daily intrathecal injection of saline, DNQX, orexin-A, or orexin-A+DNQX for 3 consecutive days after PCI. Motor function of the rats were evaluated using blood-brain barrier (BBB) score and inclined plane test 1 day before and at 1, 3, and 7 days after SCI. For patch-clamp experiment, spinal cord slices from newborn rats in the control, sham-operated, SCI, and SCI+orexin groups were prepared, and ventral horn neurons were acutely isolated to determine the reversal potential and dynamic indicators of glutamate receptor-mediated currents under glutamate perfusion. RESULTS: At 3 and 7 days after SCI, the orexin-A-treated rats showed significantly higher BBB scores and grip tilt angles than those with other interventions. Compared with those treated with DNQX alone, the rats receiving the combined treatment with orexin and DNQX had significantly higher BBB scores and grip tilt angles on day 7 after PCI. In the patch-clamp experiment, the ventral horn neurons from SCI rat models exhibited obviously higher reversal potential and greater rise slope of glutamate current with shorter decay time than those from sham-operated and orexin-treated rats. CONCLUSIONS Orexin-A promotes motor function recovery in rats after SCI possibly by improving the function of the ionotropic glutamate receptors.
Animals ; Spinal Cord Injuries/drug therapy* ; Rats ; Rats, Sprague-Dawley ; Receptors, Ionotropic Glutamate/metabolism* ; Recovery of Function/drug effects* ; Orexins/pharmacology* ; Male ; Female ; Animals, Newborn ; Neuropeptides/pharmacology* ; Intracellular Signaling Peptides and Proteins/pharmacology*

To characterize the genomes of different emm-type group A Streptococcus (GAS), their virulence genes and drug resistance profiles in Tianjin City from 2011 to 2024. After PCR, a total of 42 strains with different years and emm types were selected for whole genome sequencing and multi-locus sequence typing (MLST), and the core genomes were used to generate a phylogenetic tree, after which the virulence genes and resistance genes were identified and analyzed, followed by the drug susceptibility test. In this study, the GAS strains were dominated by emm1 (50.0%) and emm12 (40.4%), and the MLST phenotypes were categorized into six types: ST36 (40.4%), ST1274 (26.1%), ST28 (23.8%), ST921 (4.7%), ST46 (2.3%), and ST403 (2.3%). There was a high consistency between their emm-types and ST types. A total of 68 virulence genes were detected in the genomes of 42 GAS strains, involving functional genes encoding exotoxin, bacterial adhesion, extracellular enzymes, etc. The virulence genes they carried were significantly different between emm1-type and emm12-type strains, such as speA. At the same time, the carrying rates of some virulence genes in the same emm-type strains changed with time, such as hyl. The resistance genes were basically the same among different emm-type strains except for the vanSE gene detected in all emm12 strains. The results of drug sensitivity showed that the GAS strains isolated in Tianjin City from 2011 to 2024 were sensitive to penicillin, cefazolin, chloramphenicol, vancomycin, and levofloxacin, while the resistance rates to erythromycin, azithromycin, clarithromycin, and clindamycin ranged from 88.5% to 100.0%, and there was a certain degree of consistency between the resistance phenotypes and the detected resistance genes. Overall, the main emm types and evolutionary features of GAS in Tianjin City from 2011 to 2024 were consistent with the dominant types in China, and the carrying rate of virulence genes and drug resistance genes differed significantly among different emm-type strains, and there were continuous evolution and variation in the prevalence of virulence genes in GAS.

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*

Synthetic biology is a crucial tool for the development of the bio-industry and bio-economy, representing a significant aspect of new quality productive forces. As a core course for graduate students in bioengineering, Synthetic Biology plays a vital role in ensuring the supply of essential talents for the development of the bio-industry in the new era. To better serve regional economic development and provide high-level talents for China's progress in the bio-industry, we analyzed typical issues encountered in the past teaching activities, set up a multi-disciplinary teaching team, optimized the course contents, adjusted the teaching mode, and mobilized students' learning interest. With the application of scientific research project as the starting point, we guided students to think and discuss deeply through the simulation of application writing and project defense, which improved students' critical thinking and innovative thinking. With industrialization as a focus, we explored a new training model combining production, education, and research through the joint practice base of the university and enterprises introduced typical cases of biomanufacturing to encourage students to engage in scientific research. The teaching reform significantly enhances the comprehensive abilities and national sentiments of graduate students. This paper hopes to serve as a reference for colleagues engaged in teaching in this field.
Synthetic Biology/education* ; Teaching ; China ; Humans

ObjectivesTo summarize the clinical and pathological features of patients with congenital liver fibrosis （CHF）， and to investigate the differences in clinical and pathological features between patients in different age groups. MethodsA retrospective analysis was performed for the clinicopathological data of 26 patients with pathologically confirmed CHF in China-Japan Friendship Hospital from August 2005 to June 2023， and the patients were stratified by age to investigate the clinical and pathological features of patients in different age groups. ResultsAmong the 26 patients， there were 12 male patients and 14 female patients， with an age of onset of 4 — 61 years. There were 19 patients with portal hypertension type （73.08%）， 2 patients with cholangitis type （7.69%）， 4 patients with mixed type （15.38%）， and 1 patient with occult type （3.85%）. Of all 26 patients， 4 had unknown clinical symptoms， and among the 22 patients with clear clinical symptoms， 10 （45.45%） attended the hospital due to upper gastrointestinal bleeding caused by portal hypertension. Pathological manifestations included roughly normal liver parenchyma separated by fibrous septa in the portal area， with the presence of abnormal reactive bile duct hyperplasia. Denser fibrous septa and a lack of portal veins with the corresponding caliber were observed in 4 pediatric patients with disease onset before the age of 10 years， with a significant reduction or even disappearance of compensatory thin-walled blood vessels. ConclusionPortal hypertension-type CHF is the most common type in clinical practice. Patients with an early age of onset have certain histopathological features of the liver， with the presence of serious complications associated with portal hypertension. Therefore， liver biopsy should be performed for patients suspected of CHF in clinical practice， and genetic testing should be performed when necessary. Early identification and diagnosis are of great importance for improving the prognosis of patients.

Uncontrolled hemorrhage is the leading cause of potentially survivable combat casualty death,dominated by non-compressible hemorrhage in the torso and junctional areas.Rapid hemostasis using war trauma dressings is the mainstay of treatment for such casualties.The article reviews the research progress of novel hemostatic dressings for war trauma,including novel improved dressings,multifunctional dressings,electrospinning wound dressings,and smart dressings in order to provide references for the research on war trauma dressings.

Poloxamer， as a non-ionic surfactant， exhibits a unique triblock [polyethylene oxide-poly （propylene oxide）-polyethylene oxide] structure， which endows it with broad application potential in various fields， including solid dispersion technology， nanotechnology， gel technology， biologics， gene engineering and 3D printing. As a carrier， it enhances the solubility and bioavailability of poorly soluble drugs. In the field of nanotechnology， it serves as a stabilizer etc.， enriching preparation methods. In gel technology， its self-assembly behavior and thermosensitive properties facilitate controlled drug release. In biologics， it improves targeting efficiency and reduces side effects. In gene engineering， it enhances delivery efficiency and expression levels. In 3D printing， it provides novel strategies for precise drug release control and the production of high-quality biological products. As a versatile material， poloxamer holds promising prospects in the pharmaceutical field.

Objective To explore the protective effect of 7,8-dihydroxyflavone(7,8-DHF)on the retina of diabetic rats and its mechanism.Methods A total of 18 SPF-grade male Sprague-Dawley(SD)rats were selected and randomly divided into three groups:the normal group,the model group,and the experimental group,with six rats in each group.Rats in the normal group were fed with a normal diet,while those in the remaining two groups were fed with a high-fat emulsion through oral gavage continuously for 2 weeks to establish a diabetes model.Rats in the experimental group were provided with 7,8-DHF(5 mg?kg-1)by continuous intraperitoneal injection,while those in the normal and model groups were provided with an equal volume of normal saline.The rats in all groups received intervention once a day for 2 weeks.The changes in the body mass and fasting blood glucose(FBG)were observed before and after modeling.Besides,the changes in the retina of rats in each group were observed by fundus fluorescence angiography(FFA)after 2 weeks.Moreo-ver,the changes and apoptosis of retinal neuronal cells were detected by hematoxylin and eosin(HE)staining,CD31 im-munofluorescence,and terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assays.Results After 2 weeks of continuous intervention,compared with the normal group,the body mass of rats in the model and experimental groups decreased(both P＜0.05),and the FBG increased significantly(both P＜0.05);compared with the model group,the experimental group showed an increase in the body mass(P＜0.05)and a decrease in the FBG(P＜0.05).The fundus photography and FFA of rats in the three groups did not reveal any fundus features of diabetic retinopathy.The HE staining results showed that the retina of rats in the normal and experimental groups was structurally intact,with neatly arranged cells and uniform thickness;the retinal structure of rats in the model group remained clear.However,the thickness of the inner layers of the retina of rats in the model group was thinner compared with the normal and experimental groups,exhibi-ting significant differences(both P＜0.05).The CD31 immunofluorescence assay results indicated that the CD31 immuno-fluorescence intensity values of rats in the three groups were roughly comparable,without significant differences(all P＞0.05).The TUNEL assay results suggested that the apoptosis of retinal neurons increased in rats in the model group com-pared with the normal group,exhibiting significant differences(P＜0.001);compared with the model group,the apoptosis of retinal neurons of rats in the experimental group decreased significantly,displaying significant differences(P＜0.001).Conclusion The apoptosis of retinal neurons in diabetic rats may precede vascular endothelial cell injury.7,8-DHF can improve the body mass,decrease the blood glucose level,and protect the retinal neurons in diabetic rats.

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 impact of lysosomal associated membrane protein 2b(Lamp2b)modification on the mucosal immune efficacy of engineered exosome-based vaccines.METHODS In vitro experiments:The murine dendritic cell line DC2.4 was transfected with a plasmid encoding the Lamp2b-RBD fusion protein.Real-time quantitative PCR and Western blotting were employed to assess Lamp2b-RBD expressions,flow cytometry was used to evaluate the proportion of Lamp2b-RBD-positive cells,and immunofluorescence staining was performed to determine their membrane localization.Exosomes were isolated via ultracentrifugation,and their morphology and particle size distribution were examined using transmission electron microscopy and nanoparticle tracking analysis.Western blotting was applied to confirm exosomal marker proteins[cluster of differentiation 9(CD9),CD63,ALG-2-interacting protein X(Alix),and Golgi marker GM130]and Lamp2b-RBD expression.In vivo experiments:① Female BALB/c mice were divided into the Lamp2b-RBD-Exo group and the lipid nanoparticle(LNP)group,and administered intratracheally for mucosal immunization.Pulmonary reten-tion was assessed by immunofluorescence staining.② Female BALB/c mice were divided into three groups:placebo group(PBS group),Lamp2b-RBD-Exo intratracheal administration group,and Lamp2b-RBD-Exo intramuscular injection group(im).Immunizations were performed on days 0 and 14,and on days 7 and 21.The titers of RBD-specific immunoglobulin G(IgG)in serum and RBD-specific IgA and IgG antibodies in bronchoalveolar lavage fluid were determined by enzyme-linked immunosor-bent assay(ELISA).RESULTS In vitro experiments:Lamp2b-RBD-positive cells accounted for 71.16％.Lamp2b-RBD mRNA levels were upregulated 1 979-fold compared with controls,with Lamp2b-RBD proteins localized on the cell membrane.Purified engineered exosomes displayed regular morphology,expressed CD9,CD63,and Alix but not GM130,had an average diameter of approximately 124 nm,and carried 3 009 pg of RBD protein per 1×109 exosomes.In vivo experiments:At 4 h after administra-tion,fluorescence signals were observed in the lung tissues of both the Lamp2b-RBD-Exo and LNPs groups.At 24 h,the fluorescence signal in the LNPs group shifted to the liver,while in the Lamp2b-RBD-Exo group,the fluorescence expanded from the trachea to the bronchioles and lung tissue,showing significantly better distribution and retention capacity than the LNPs group.Seven days after immuniza-tion,both the Lamp2b-RBD-Exo and Lamp2b-RBD-Exo(im)groups induced RBD-specific IgG antibody titers.At 21 days after immunization,Lamp2b-RBD-Exo elicited a higher level of RBD-specific immune response,with serum IgG titers reaching 1∶8 100 and bronchoalveolar lavage fluid(BALF)IgA titers reaching 1∶300.No RBD-specific IgA antibody titers were detected in the BALF of the Lamp2b-RBD-Exo(im)group.CONCLUSION Lamp2b-RBD modification enables efficient RBD protein loading and enhances pulmonary retention of engineered exosomes,thereby inducing potent antigen-specific mucosal immune responses.