Tumors are the second leading cause of death worldwide. Exosomes are a type of extracellular vesicle secreted from multivesicular bodies, with particle sizes ranging from 40 to 160 nm. They regulate the tumor microenvironment, proliferation, and progression by transporting proteins, nucleic acids, and other biomolecules. Compared with other drug delivery systems, exosomes derived from different cells possess unique cellular tropism, enabling them to selectively target specific tissues and organs. This homing ability allows them to cross biological barriers that are otherwise difficult for conventional drug delivery systems to penetrate. Due to their biocompatibility and unique biological properties, exosomes can serve as drug delivery systems capable of loading various anti-tumor drugs. They can traverse biological barriers, evade immune responses, and specifically target tumor tissues, making them ideal carriers for anti-tumor therapeutics. This article systematically summarizes the methods for exosome isolation, including ultracentrifugation, ultrafiltration, size-exclusion chromatography (SEC), immunoaffinity capture, and microfluidics. However, these methods have certain limitations. A combination of multiple isolation techniques can improve isolation efficiency. For instance, combining ultrafiltration with SEC can achieve both high purity and high yield while reducing processing time. Exosome drug loading methods can be classified into post-loading and pre-loading approaches. Pre-loading is further categorized into active and passive loading. Active loading methods, including electroporation, sonication, extrusion, and freeze-thaw cycles, involve physical or chemical disruption of the exosome membrane to facilitate drug encapsulation. Passive loading relies on drug concentration gradients or hydrophobic interactions between drugs and exosomes for encapsulation. Pre-loading strategies also include genetic engineering and co-incubation methods. Additionally, we review approaches to enhance the targeting, retention, and permeability of exosomes. Genetic engineering and chemical modifications can improve their tumor-targeting capabilities. Magnetic fields can also be employed to promote the accumulation of exosomes at tumor sites. Retention time can be prolonged by inhibiting monocyte-mediated clearance or by combining exosomes with hydrogels. Engineered exosomes can also reshape the tumor microenvironment to enhance permeability. This review further discusses the current applications of exosomes in delivering various anti-tumor drugs. Specifically, exosomes can encapsulate chemotherapeutic agents such as paclitaxel to reduce side effects and increase drug concentration within tumor tissues. For instance, exosomes loaded with doxorubicin can mitigate cardiotoxicity and minimize adverse effects on healthy tissues. Furthermore, exosomes can encapsulate proteins to enhance protein stability and bioavailability or carry immunogenic cell death inducers for tumor vaccines. In addition to these applications, exosomes can deliver nucleic acids such as siRNA and miRNA to regulate gene expression, inhibit tumor proliferation, and suppress invasion. Beyond their therapeutic applications, exosomes also serve as tumor biomarkers for early cancer diagnosis. The detection of exosomal miRNA can improve the sensitivity and specificity of diagnosing prostate and pancreatic cancers. Despite their promising potential as drug delivery systems, challenges remain in the standardization and large-scale production of exosomes. This article explores the future development of engineered exosomes for targeted tumor therapy. Plant-derived exosomes hold potential due to their superior biocompatibility, lower toxicity, and abundant availability. Furthermore, the integration of exosomes with artificial intelligence may offer novel applications in diagnostics, therapeutics, and personalized medicine.

[Objective] To establish a cryopreservation protocol for small-volume (≤1 mL) red blood cells (RBCs) and to evaluate the reactivity and stability of blood group antigens after cryopreservation, so as to explore its potential application in immunohematology reference laboratories. [Methods] Small-volume RBCs were cryopreserved for 120 days, followed by thawing and deglycerolization to restore the RBC components. The quality of the RBCs was assessed. Serum antibodies were serially diluted and reacted with RBCs before and after cryopreservation, and agglutination scores were recorded to quantitatively evaluate the reactivity and stability of blood group antigens such as Rh, Duffy, Lewis, Kidd, M, and H. Flow cytometry was used to analyze the percentage and mean fluorescence intensity of ABO antigen expression on RBCs before and after cryopreservation to assess the usability of cryopreserved RBCs in flow immunophenotyping and blood group subtype studies. [Results] The hemolysis rate of thawed and deglycerolized RBCs was (0.27±0.10)%, with a supernatant free hemoglobin level of (0.52±0.14) g/L, and the RBC recovery rate was (69.12±7.91)%. The direct antiglobulin test (DAT) was negative for all thawed RBCs. There was no difference in the reactivity of blood group antigens before and after cryopreservation, and no difference in the percentage and mean fluorescence intensity of A and B antigen expression on RBCs before and after cryopreservation. [Conclusion] The small-volume RBC cryopreservation protocol can be applied to immunohematology analysis in reference laboratories and is expected to be widely used in blood group identification, antibody screening, identification, and blood group-related research.

Overexpression of P-glycoprotein(P-gp)is one of the major causes of therapeutic resistance to a variety of drugs,in-cluding antitumor drugs.P-gp has a wide range of substrates that are capable of expelling drugs from the cell via a twist-squeeze mechanism,leading to drug resistance.To address the problem of P-gp-mediated multidrug resistance,several inhibitors are being investigated.This article reviews the current small mole-cule compounds,natural source compounds and pharmaceutical excipients capable of inhibiting P-gp,and summarizes the cur-rent mechanisms of action of P-gp inhibitors,which are mainly competitive or non-competitive inhibition,stimulation of ATPase activity,down-regulation of expression,and metamorphic modu-lation.Currently,it is mainly the drug interactions and toxic re-actions that limit their clinical applications.

The purpose of this study was to investigate the damage mechanism of pathogenic E.coli on mouse brain microvascular endothelial cells(BMEC cells)and mouse alveolar macrophages(MH-S cells),as well as the lung and brain of healthy mice.In this study,BMEC cells and MH-S cells were infected with pathogenic E.coli strains,and cell morphological changes were observed.Plate counting method was used to detect the adhesion and invasion ability of the strains to cells and the number of bacteria in the lungs and brains of mice.RT-qPCR was used to detect the ex-pression of TNF-α,IL-1β and IL-6 genes in cells and mouse organs at different time periods.West-ern blot was used to detect the expression of p-NF-κB,p-JAK2 and p-STAT3 proteins related to inflammation in cells and mouse organs after infection.The results showed that the cell culture medium of the infection group was turbid,the cell vision became dark and blurred,some cells shrank and died,and more fragments were produced.The adhesion rate and invasion rate of BMEC cells at 3 h were significantly lower than those at 6 h(P＜0.050),and the adhesion rate and inva-sion rate of MH-S cells at 3 h were significantly higher than those at 6 h(P＜0.010).Infected mice had a large area of swelling and bleeding in the brain,and the lungs had different degrees of swell-ing and bleeding.The bacterial load in the brain and lung was the highest at 12 h.Compared with the control group,the mRNA expression levels of IL-1β,IL-6 and TNF-α in the infection group were significantly increased at 3 h and 6 h(P＜0.050),and the mRNA expression levels of inflam-matory factors in BMEC cells and MH-S cells were the highest at 6 and 3 h,respectively.The mR-NA expression of inflammatory factors in the brain and lung of infected mice showed a trend of in-creasing first and then decreasing with time,with the highest expression at 12 h after infection.The expression levels of p-NF-κB protein in BMEC cells,MH-S cells,lung and brain tissues of mice in the infection group were significantly higher than those in the control group(P＜0.001),and the expression levels of p-JAK2 protein and p-STAT3 protein were significantly lower than those in the control group(P＜0.050).The above results showed that pathogenic E.coli could adhere and invade BMEC cells and MH-S cells,colonize in lung and brain tissues of mice,promote the expres-sion of NF-κB protein in cells and tissues,inhibit the expression of JAK2 protein and STAT3 pro-tein,and then stimulate cells and tissues to produce inflammatory response.

Objective:To investigate the correlation of miR-155 expression with drug sensitivity of FLT3-ITD+acute myeloid leukemia(AML)cell line and its potential regulatory mechanism.Methods:By knocking out miR-155 gene in FLT3-ITD+AML cell line MV411 through CRISPR/Cas9 gene-editing technology,monoclonal cells were screened.The genotype of these monoclonal cells was validated by PCR and Sanger sequencing.The expression of mature miRNA was measured by RT-qPCR.The treatment response of doxorubicin,quizartinib and midostaurin were measured by MTT assay and IC50 of these drugs were calculated to identify the sensitivity.Transcriptome sequencing was used to analyze change of mRNA level in MV411 cells after miR-155 knockout,gene set enrichment analysis to analyze change of signaling pathway,and Western blot to verify expressions of key molecules in signaling pathway.Results:Four heterozygotes with gene knockout and one heterozygote with gene insertion were obtained through PCR screening and Sanger sequencing.RT-qPCR results showed that the expression of mature miR-155 in the monoclonal cells was significantly lower than wild-type clones.MTT results showed that the sensitivity of MV411 cells to various anti FLT3-ITD+AML drugs increased significantly after miR-155 knockout compared with wild-type clones.RNA sequencing showed that the mTOR signaling pathway and Wnt signaling pathway were inhibited after miR-155 knockout.Western blot showed that the expressions of key molecules p-mTOR,Wnt5α and β-catenin in signaling pathway were down-regulated.Conclusion:Drug sensitivity of MV411 cells to doxorubicin,quizartinib and midostaurin can be enhanced significantly after miR-155 knockout,which is related to the inhibition of multiple signaling pathways including mTOR and Wnt signaling pathways.

Objective:To screen interleukin(IL)-1β secretion-related membrane transporters by macrophage experiment in vitro and conventional knockout mice.Methods:THP-1 cell line was differentiated to obtain human THP-1-derived macrophages,and the primary macrophages were obtained from human peripheral blood.FVB wild-type mice with the same sex and age were used as the controls of MRP1 knockout mice.The macrophages in abdominal cavity and bone marrow of mice were cultivated.The cells were treated with ABCC1/MRP1,ABCG2/BCRP,ABCB1/P-gp,OATP1B1,and MATE transporter inhibitors,then stimulated by lipopolysaccharide and adenosine triphosphate.The secretion level of IL-iβ was detected by ELISA,Western blot,and immunofluorescence.Results:After inhibiting ABCC1/MRP1 transporter,the secretion of IL-1β decreased significantly,while inhibition of the other 4 transporters had no effect.In animal experiment,the level of IL-1 β secreted by macrophages in bone marrow of MRP1 knockout mice was significantly lower than control group(P＜0.05).Conclusion:ABCC1/MRP1 transporter is a newly discovered IL-1β secretion pathway,which is expected to become a new target for solving clinical problems such as cytokine release syndrome.

Objective:To detect the pharmacokinetic(PK)parameters of coagulation factor Ⅷ(FⅧ)in adult patients with severe hemophilia A,identify the potential factors influencing FⅧ PK,and optimize the use of FⅧ in individual prophylaxis regimens.Methods:PK characteristics of FⅧ were studied in a total of 23 severe hemophilia A adults.The correlation of patients'characteristics including age,von Willebrand factor antigen(vWF:Ag),blood group,weight,body mass index(BMI)and FⅧ genotype,with FⅧ PK were evaluated.Individual prophylaxis regimens were given based on FⅧ PK parameters.Results:The mean terminal half-life(t1/2)of FⅧ was 20.6±9.3 h,ranged from 11.47 h to 30.12 h.The age(r=0.580)and vWF:Ag(r=0.814)were significantly positively correlated with t1/2 of FⅧ.The mean area under the plasma concentration curve(AUC)of FⅧ was 913±399(328-1 878)IU h/dl,and the AUC of FⅧ was positively correlated with age(r=0.557)and vWF:Ag(r=0.784).The mean residence time(MRT)of FⅧ was 24.7±12.4(13.2-62.2)h,and the MRT of FⅧ was positively correlated with age(r=0.664)and vWF:Ag(r=0.868).The mean in vivo recovery(IVR)of FⅧ was 2.59±0.888(1.5-4.29)IU/dl per IU/kg,the mean clearance(CL)of FⅧ was 3±1.58(0.97-7.18)ml/(kg·h),and there was no significant correlation of IVR and CL with age and vWF:Ag.According to the individual PK parameters,ultra low-dose,low-dose and moderate-dose FⅧ were applied to 15,6,2 adults patients with severe hemophilia A for prophylaxis,respectively.Conclusion:There are significant individual differences in the FⅧ half-life of adult patients with severe hemophilia A.The older the patient,the higher the vWF:Ag level,and the longer the FⅧ half-life.Individual administration is required based on the FⅧ PK parameters to optimize prophylaxis treatment.