Cats, owing to their physiological and immunological similarities with humans, have become increasingly valuable as model animals in virology research, drug development, and vaccine evaluation. They are irreplaceable in studies of feline immunodeficiency virus, feline coronavirus, and other related pathogens. However, cats are temperamentally sensitive, exhibit strong stress responses, and possess well-developed nervous systems as well as sharp claws and teeth. Consequently, the biosafety risks associated with infectious experiments using cats in animal biosafety level 2 laboratory (ABSL-2) are significantly higher than those encountered with conventional rodents. Drawing on long-term ABSL-2 operational experience, this article systematically reviews the entire workflow of infectious experiments in laboratory cats — from animal selection, pre-entry preparation, reception and quarantine, housing management, to infectious experimental procedures and incident response — identifying and addressing critical risk points at each stage. For strain selection, SPF-grade shorthair cats with defined genetic backgrounds and docile temperaments are recommended; sex and age should be scientifically matched to experimental objectives. During pre-entry preparation, emphasis is placed on dual-credential personnel management, health surveillance, standardized disinfection of environments and cages, feed and water standards, and robust record-keeping. During reception and quarantine, standardized protocols are established for transport control, appearance inspection, isolation quarantine, pathogen exclusion, and positive-reinforcement training. During infectious experimentation, a "three-fixed" husbandry principle is clearly implemented: dedicated caretakers, fixed feeding/cleaning times, and fixed cage positions. Disinfectant selection, autoclaving of waste, and daily veterinary rounds are rigorously enforced. Operational risk control includes detailed measures for graded personal protection, animal anesthesia and restraint, zoned operation within biosafety cabinets, and disposal of experimental waste. Contingency plans are formulated to address animal death, escape, personnel exposure, and spills of infectious materials. This study provides a reproducible and scalable technical pathway and operational standard for conducting infectious experiments in laboratory cats in ABSL-2 laboratories, offering a reference for other facilities undertaking similar work.

ObjectiveTo prepare rabbit anti-porcine inhibin polypeptide-keyhole limpet hemocyanin(KLH) conjugated polyclonal antibody and evaluate its effect on superovulation in C57BL/6J mice. MethodsNew Zealand white rabbits were immunized with a synthesized porcine inhibin polypeptide conjugated with KLH to produce anti-inhibin serum (AIS, i.e., inhibin polyclonal antibody). Female C57BL/6J mice received intraperitoneal injections of purified AIS in combination with pregnant mare serum gonadotropin (PMSG), followed by human chorionic gonadotropin (hCG) after 48 hours to induce superovulation. Oocytes obtained from superovulation were collected and counted 15 hours post-hCG administration, and the number of 2-cell embryos was assessed 24 hours after in vitro fertilization. ResultsAIS prepared by immunizing New Zealand White rabbits with KLH-conjugated porcine inhibin polypeptide was subjected to titer determination by indirect ELISA, showing titers reaching 1∶ 512 000. SDS-polyacrylamide gel electrophoresis analysis of ammonium sulfate-purified AIS revealed distinct 50 kDa and 25 kDa bands corresponding to the theoretical molecular weights of IgG antibody heavy and light chains, confirming successful production of porcine inhibin polyclonal antibody. Compared with conventional superovulation methods, AIS diluted 10-fold combined with PMSG significantly increased the number of oocytes obtained from superovulation in mice (P<0.05) by approximately 1.5-fold. ConclusionPorcine inhibin polyclonal antibody, as an improved superovulation reagent, can improve superovulation efficiency in C57BL/6J mice, and shows promising prospects for future applications.

BACKGROUND:Cell-free therapy is a research hotspot in the field of medical cosmetic anti-aging.It is still unknown for paracellular secretion of human umbilical cord mesenchymal stem cell-derived small extracellular vesicles loaded with the antiaging drug α-ketoglutaric acid to delay skin aging.OBJECTIVE:To investigate the effect of the anti-aging agent α-ketoglutarate engineered human umbilical cord mesenchymal stem cell-derived small extracellular vesicles in a D-galactose-induced model of dermal fibroblast senescence.METHODS:(1)Biological characteristics of primary human umbilical cord mesenchymal stem cells were identified by osteogenic-lipogenic differentiation staining and flow cytometry.(2)The small extracellular vesicles derived from human umbilical cord mesenchymal stem cell were obtained by using differential-ultracentrifugation.α-Ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles were constructed by electroporation,and biologically characterized by transmission electron microscopy and nanoparticle tracking analyzer,while the encapsulation rate was assessed using high-performance liquid chromatography.(3)The effect of α-ketoglutarate on the proliferative capacity of dermal fibroblasts was assessed by CCK-8 and Edu cell proliferation assay kits.(4)The effect of α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles on delaying the senescence of dermal fibroblasts was evaluated by reactive oxygen species detection kit,western blot assay,and cellular immunofluorescence.RESULTS AND CONCLUSION:(1)The obtained human umbilical cord mesenchymal stem cell and human umbilical cord mesenchymal stem cell-small extracellular vesicles were biologically compatible.(2)There was no toxic effect on dermal fibroblasts when α-ketoglutarate was used in the concentration range of 0.5-8 mmol/L.(3)D-gal induced senescence in dermal fibroblasts,while α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles treatment reduced the level of oxidative stress,DNA damage,and collagen loss,which was further verified that α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles could effectively slow down the skin aging process.

BACKGROUND:Cell-free therapy is a research hotspot in the field of medical cosmetic anti-aging.It is still unknown for paracellular secretion of human umbilical cord mesenchymal stem cell-derived small extracellular vesicles loaded with the antiaging drug α-ketoglutaric acid to delay skin aging.OBJECTIVE:To investigate the effect of the anti-aging agent α-ketoglutarate engineered human umbilical cord mesenchymal stem cell-derived small extracellular vesicles in a D-galactose-induced model of dermal fibroblast senescence.METHODS:(1)Biological characteristics of primary human umbilical cord mesenchymal stem cells were identified by osteogenic-lipogenic differentiation staining and flow cytometry.(2)The small extracellular vesicles derived from human umbilical cord mesenchymal stem cell were obtained by using differential-ultracentrifugation.α-Ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles were constructed by electroporation,and biologically characterized by transmission electron microscopy and nanoparticle tracking analyzer,while the encapsulation rate was assessed using high-performance liquid chromatography.(3)The effect of α-ketoglutarate on the proliferative capacity of dermal fibroblasts was assessed by CCK-8 and Edu cell proliferation assay kits.(4)The effect of α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles on delaying the senescence of dermal fibroblasts was evaluated by reactive oxygen species detection kit,western blot assay,and cellular immunofluorescence.RESULTS AND CONCLUSION:(1)The obtained human umbilical cord mesenchymal stem cell and human umbilical cord mesenchymal stem cell-small extracellular vesicles were biologically compatible.(2)There was no toxic effect on dermal fibroblasts when α-ketoglutarate was used in the concentration range of 0.5-8 mmol/L.(3)D-gal induced senescence in dermal fibroblasts,while α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles treatment reduced the level of oxidative stress,DNA damage,and collagen loss,which was further verified that α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles could effectively slow down the skin aging process.

[Objective]To clarify the therapeutic effect of five groups of ascending and descending drugs on ulcerative colitis(UC),and to explore its different characteristics and potential regulatory pathways.[Methods]Sixty-four C57BL/6J male mice were randomly divided into normal control group,model control group,positive control group and five groups of ascending and descending drug groups,with 8 mice in each group.The UC model of mice was induced by dextran sulfate sodium(DSS).Except for the normal control group,the other groups of mice freely drank 2.5%DSS solution every day,and the mice in each drug group were given corresponding doses of drugs by gavage.During the modeling period,the state of the mice was observed every day,and the body weight,food intake,water intake and fecal morphology of the mice were recorded.At the end of the experiment,the disease activity index(DAI)score and colonic histopathological changes of mice in each group were compared.Transcriptome sequencing was used to analyze the differentially expressed genes in the colon of mice in each intervention group.Real-time quantitative polymerase chain reaction(RT-qPCR)was used to detect the expression level of node genes in key signaling pathway.[Results]Compared with normal control group,the DAI score of the mice in model control group was significantly increased(P<0.0001),the body weight was significantly decreased(P<0.05),the colon was significantly shortened(P<0.05),and a large number of inflammatory cell infiltration was observed.Compared with model control group,the diet of UC mice in Citri Reticulatae Pericarpium-Aurantii Fructus Immaturus group increased gradually;Platycodonis Radix-Armeniacae Semen Amarum group still had formed feces after modeling;the expression of estrogen signaling pathway-related genes closely related to pro-inflammatory response was down-regulated in Scutellariae Radix-Pinelliae Rhizoma Praeparatum Cum Zingibere Et Alumine group;the DAI index of UC mice in Atractylodis macrocephalae Rhizoma-Poria cocos group was significantly lower than that in other groups,and the liver index of UC mice in Atractylodis macrocephalae Rhizoma-Paeoniae Radix Alba group was significantly lower than that in model control group(P<0.01).The G protein-coupled receptors(GPCRs)signaling pathway was up-regulated in the Atractylodis macrocephalae Rhizoma-Poria cocos group and Atractylodis macrocephalae Rhizoma-Paeoniae Radix Alba group.[Conclusion]The five groups of ascending and descending drug pairs had different therapeutic characteristics in the treatment of UC induced by DSS.Among them,Citri Reticulatae Pericarpium-Aurantii Fructus Immaturus group,Atractylodis macrocephalae Rhizoma-Poria cocos group and Atractylodis macrocephalae Rhizoma-Paeoniae Radix Alba group had obvious improvement effects on colon tissue pathological damage and submucosal collagen deposition.The protective effect on colonic goblet cells was relatively obvious in Atractylodis macrocephalae Rhizoma-Poria cocos group and Atractylodis macrocephalae Rhizoma-Paeoniae Radix Alba group.The reduction of apolipoprotein A1(ApoA1)was most significant in Atractylodis macrocephalae Rhizoma-Poria cocos group,and the down-regulation of CXC chemokine ligand 10(CXCL10)gene expression was most obvious in Platycodonis Radix-Armeniacae Semen Amarum group.In general,the protective effect of Atractylodis macrocephalae Rhizoma-Poria cocos drug pair on UC was more comprehensive and worthy of further study.

Sonodynamic therapy（SDT）has garnered significant attention in cancer treatment modalities due to its superior tissue penetration capabilities，non-invasive approach，and controllability. SDT operates by utilizing sonosensitizers and ultrasound-responsive devices to induce the production of reactive oxygen species（ROS）under ultrasound stimulation，thereby eliciting immunogenic cell death（ICD）in tumor cells and the release of damage-associated molecular patterns，which in turn trigger an immune response against the tumor.However，the tumor microenvironment often results in a relatively weak immune response post-cancer treatment. To address this issue，extensive research is being conducted on combining SDT with immunotherapy，particularly focusing on immune checkpoint blockade（ICB）therapies. This review synthesizes the mechanisms of SDT，its integration with immunotherapy，especially ICB therapies，and the current state of research，with the objective of providing strategic guidance for the advancement of sonodynamic immunotherapy.

BACKGROUND:Topical administration of tranexamic acid can be used for anti-skin pigmentation,but its large polarity makes it difficult to break through the cuticle barrier and cell membrane when administered topically,and the subcutaneous accumulation concentration is not easy to reach the effective therapeutic concentration.OBJECTIVE:To design functionalized self-assembled micelles to enhance the anti-pigmentation effect of tranexamic acid.METHODS:The plant polyphenol derivative epigallocatechin gallate palmitate and metformin were used as carrier materials.The self-assembled micelles with synergistic anti-pigging activity and enhanced drug permeability were prepared by hydrogen bonding and electrostatic interaction.The nanoscale properties and stability of self-assembled drug-loaded micelles were tested,and their transdermal permeability was evaluated,and their biocompatibility and cellular effects were investigated.RESULTS AND CONCLUSION:(1)Functional self-assembled drug-carrying micelles with average particle size of(176.27±5.23)nm,polydispersity coefficient of 0.23±0.02,and the Zeta potential of(-25.67±0.98)mV had good stability.The mass concentrations of tranexamic acid and metformin in the self-assembled drug-carrying micelles were(20.03±0.12)and(6.67±0.08)mg/mL,respectively.The drug loadings of tranexamic acid and metformin in the self-assembled drug-carrying micelles were(19.97±0.12)％and(6.65±0.08)％,respectively.(2)In vitro transdermal results showed that the self-assembled drug-carrying micelles had higher penetration and intradermal retention per unit skin area,and could penetrate and diffuse to deeper parts of the skin.(3)MTT assay results demonstrated that undrug-loaded self-assembled micelles containing tranexamic acid 50-250 μg/mL had no toxic effects on mouse fibroblasts and mouse skin melanoma cells.The self-assembled drug-carrying micelles containing tranexamic acid 500 μg/mL had a slight toxic effect on mouse skin melanoma cells.The self-assembled drug-carrying micelles containing 50-500 μg/mL of tranexamic acid did not cause hemolysis and had good biological safety.(4)In vitro cell culture results showed that self-assembled drug-carrying micelles containing 500 μg/mL tranexamic acid could significantly inhibit the tyrosinase activity and melanin release of mouse skin melanoma cells,and the inhibitory effect was stronger than that of tranexamic acid solution or metformin solution alone.These results indicated that functionalized self-assembled micelles could synergize with tranexamic acid to inhibit tyrosinase activity,reduce melanin synthesis,and enhance the anti-skin pigmentation effect of tranexamic acid.

The concept of"musculoskeletal imbalance with soft tissue primacy"posits that tendon injury induced by intervertebral disc degeneration constitutes the core pathogenesis of spinal musculoskeletal imbalance.This study systematically elucidates the pathological mechanisms through which tendon injury leads to spinal instability by integrating traditional Chinese medicine(TCM)"musculoskeletal balance"theory with contemporary biomechanical research on disc degeneration.In the process of intervertebral disc degeneration,the change of stress distribution revealed by modern biomechanics is highly consistent with the TCM principle of"tendon impairment affecting bone".Finite element analysis revealing the"stability-instability-restabilization"process further validates the pathological progression from musculoskeletal imbalance to rebalance.This integrated TCM-Western medicine perspective establishes a novel theoretical framework for predicting disease progression and developing personalized therapeutic strategies,particularly in guiding clinical practice of"treating bone disorders through tendon regulation".

The concept of"musculoskeletal imbalance with soft tissue primacy"posits that tendon injury induced by intervertebral disc degeneration constitutes the core pathogenesis of spinal musculoskeletal imbalance.This study systematically elucidates the pathological mechanisms through which tendon injury leads to spinal instability by integrating traditional Chinese medicine(TCM)"musculoskeletal balance"theory with contemporary biomechanical research on disc degeneration.In the process of intervertebral disc degeneration,the change of stress distribution revealed by modern biomechanics is highly consistent with the TCM principle of"tendon impairment affecting bone".Finite element analysis revealing the"stability-instability-restabilization"process further validates the pathological progression from musculoskeletal imbalance to rebalance.This integrated TCM-Western medicine perspective establishes a novel theoretical framework for predicting disease progression and developing personalized therapeutic strategies,particularly in guiding clinical practice of"treating bone disorders through tendon regulation".

BACKGROUND:Topical administration of tranexamic acid can be used for anti-skin pigmentation,but its large polarity makes it difficult to break through the cuticle barrier and cell membrane when administered topically,and the subcutaneous accumulation concentration is not easy to reach the effective therapeutic concentration.OBJECTIVE:To design functionalized self-assembled micelles to enhance the anti-pigmentation effect of tranexamic acid.METHODS:The plant polyphenol derivative epigallocatechin gallate palmitate and metformin were used as carrier materials.The self-assembled micelles with synergistic anti-pigging activity and enhanced drug permeability were prepared by hydrogen bonding and electrostatic interaction.The nanoscale properties and stability of self-assembled drug-loaded micelles were tested,and their transdermal permeability was evaluated,and their biocompatibility and cellular effects were investigated.RESULTS AND CONCLUSION:(1)Functional self-assembled drug-carrying micelles with average particle size of(176.27±5.23)nm,polydispersity coefficient of 0.23±0.02,and the Zeta potential of(-25.67±0.98)mV had good stability.The mass concentrations of tranexamic acid and metformin in the self-assembled drug-carrying micelles were(20.03±0.12)and(6.67±0.08)mg/mL,respectively.The drug loadings of tranexamic acid and metformin in the self-assembled drug-carrying micelles were(19.97±0.12)％and(6.65±0.08)％,respectively.(2)In vitro transdermal results showed that the self-assembled drug-carrying micelles had higher penetration and intradermal retention per unit skin area,and could penetrate and diffuse to deeper parts of the skin.(3)MTT assay results demonstrated that undrug-loaded self-assembled micelles containing tranexamic acid 50-250 μg/mL had no toxic effects on mouse fibroblasts and mouse skin melanoma cells.The self-assembled drug-carrying micelles containing tranexamic acid 500 μg/mL had a slight toxic effect on mouse skin melanoma cells.The self-assembled drug-carrying micelles containing 50-500 μg/mL of tranexamic acid did not cause hemolysis and had good biological safety.(4)In vitro cell culture results showed that self-assembled drug-carrying micelles containing 500 μg/mL tranexamic acid could significantly inhibit the tyrosinase activity and melanin release of mouse skin melanoma cells,and the inhibitory effect was stronger than that of tranexamic acid solution or metformin solution alone.These results indicated that functionalized self-assembled micelles could synergize with tranexamic acid to inhibit tyrosinase activity,reduce melanin synthesis,and enhance the anti-skin pigmentation effect of tranexamic acid.