BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

BACKGROUND:Socket-shield technique can effectively maintain labial soft and hard tissues,but the incidence of postoperative complications such as exposure and displacement of root shield is relatively high.It is speculated that the root shield may be exposed and displaced due to excessive load after long-term function of dental implants. OBJECTIVE:Through three-dimensional finite element analysis,we aim to study the influence of varying root shield thicknesses on the stress distribution,equivalent stress peaks,and displacement in the root shield,periodontal ligaments,implant,and surrounding alveolar bone under normal occlusal loading.We also attempt to analyze the correlation between the thickness of the root shield and occurrence of mechanical events such as root shield exposure,displacement,and fracture. METHODS:Cone-beam CT data of a patient who met the indication standard of socket-shield technique for maxillary central incisor were retrieved from database.Reverse engineering techniques were used to build models of the maxillary bone and root shield,while forward engineering was used to create models for the implant components based on their parameters.Models depicting various root shield thicknesses(0.5,1.0,1.5,and 2.0 mm)were created using Solidworks 2022 software.ANSYS Workbench 2021 software was then used to simulate and analyze the effects of varying root shield thicknesses on stress distribution,equivalent stress peaks,and displacement of the root shields,periodontal ligaments,implants,and surrounding alveolar bone under normal occlusion. RESULTS AND CONCLUSION:(1)In all root shield models,the stress was concentrated on the palatal cervical side,both sides of the edges and the lower edge of the labial side.As the thickness of the root shield increased,the equivalent stress peak and displacement showed a decreasing trend.The 0.5 mm thickness model produced a stress concentration of 176.20 MPa,which exceeded the yield strength(150 MPa)of tooth tissue.(2)The periodontal ligament stress in each group was concentrated in the neck margin and upper region.With the increase of root shield thickness,the equivalent stress peak and displacement of periodontal ligament showed a decreasing trend.(3)Implant stress in all models was concentrated in the neck of the implant and the joint of the implant-repair abutment,and the labial side was more concentrated than the palatal side.With the increase of root shield thickness,the equivalent stress peak of the implant in the model showed an increasing trend.(4)In each group of models,stress of cortical bone concentrated around the neck of the implant and the periphery of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the equivalent stress peak around the root shield decreased;the peak value of the equivalent stress of the bone around the neck of the implant showed an increasing trend.In the model,the stress of cancellous bone was mainly concentrated around the neck of the lip of the implant,the top of the thread,the root tip and the lower margin of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the peak value of the equivalent stress of the bone around the root shield in the model showed a decreasing trend.The minimum principal stress of cortical bone in each group of models was concentrated around the neck of the implant,exhibiting a fan-shaped distribution.As the thickness of the root shield increased,the minimum principal stress of cortical bone showed an increasing trend.(5)These results indicate that different thicknesses of the root shield have different biomechanical effects.The root shield with a thickness of 0.5 mm is easy to fracture.For patients with sufficient bone width,the root shield with a thickness of 2.0 mm is an option to reduce the risk of complications such as root shield exposure,fracture,and displacement.Meanwhile,it should be taken into account to protect the periodontal ligament in the preparation process,and rounding treatments ought to be carried out on both sides and the lower edge of the root shield.

Aralia taibaiensi, widely distributed in western China, particularly in the Qinba Mountains, has been utilized as a folk medicine for treating diabetes, gastropathy, rheumatism, and cardiovascular diseases. Saponins from A. taibaiensis (sAT) have demonstrated protective effects against oxidative stress and mitochondrial dysfunction induced by ischemia/reperfusion (I/R). However, the underlying mechanisms remain unclear. In vivo, middle cerebral artery occlusion/reperfusion (MCAO/R) induced inflammatory infiltration, neuronal injury, cell apoptosis, mitochondrial dysfunction, and oxidative stress in the ischaemic penumbra, which were effectively mitigated by sAT. sAT increased the mRNA and protein expression levels of apelin and its receptor apelin/apelin receptors (ARs) both in vivo and in vitro. (Ala13)-Apelin-13 (F13A) and small interfering RNA (siRNA) abolished the regulatory effects of sAT on neuroprotection mediated by adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/protein kinase B (Akt). Furthermore, sAT induced apelin/AR expression by simultaneously inhibiting P38 mitogen-activated protein kinase (P38 MAPK)/activating transcription factor 4 (ATF4) and upregulating hypoxia-inducible factor-1α (HIF-1α). Our findings indicate that sAT regulates apelin/AR/AMPK by inhibiting P38 MAPK/ATF4 and upregulating HIF-1a, thereby suppressing oxidative stress and mitochondrial dysfunction.
Animals ; Reperfusion Injury/prevention & control* ; Aralia/chemistry* ; Saponins/administration & dosage* ; AMP-Activated Protein Kinases/genetics* ; Male ; Apelin/genetics* ; Signal Transduction/drug effects* ; Neuroprotective Agents/administration & dosage* ; Brain Ischemia/genetics* ; Rats, Sprague-Dawley ; Rats ; Oxidative Stress/drug effects* ; Apelin Receptors/genetics* ; Humans ; Apoptosis/drug effects* ; Mice

Objective:To explore the feasibility of using a simplified multiple sleep latency test (MSLT) for the diagnosis of narcolepsy type 1.Methods:Data from 158 patients with narcolepsy type 1 and 58 patients with non-type 1 narcolepsy who underwent overnight video-polysomnography (V-PSG) and MSLT in the Sleep Center, Department of Neurology, Xijing Hospital, Air Force Military Medical University from March 2019 to April 2024 were retrospectively collected. By reducing the number of naps in the MSLT, the diagnostic consistency between the simplified MSLT and the standard 5-nap MSLT was evaluated using the receiver operating characteristic (ROC) curve. The DeLong test was used to compare whether there was a statistically significant difference between the simplified MSLT and the standard 5-nap MSLT. Cohen′s Kappa statistical analysis was performed to compare the diagnostic consistency between the simplified MSLT and the standard 5-nap MSLT.Results:The age of the 216 patients who were ultimately enrolled was 17 (13, 30) years, including 152 male patients (70.4%). The Cohen′s Kappa between the simplified 3-nap MSLT and the standard 5-nap MSLT was 0.875, which was 0.903 between the simplified 4-nap MSLT and the standard 5-nap MSLT (Bonferroni-corrected, both P0.001), indicating high and statistically significant agreement for both simplified protocols with the standard test. However, the DeLong test revealed that the area under the curve of the standard 5-nap MSLT (0.900, 95% CI 0.863-0.938) differed significantly from that of the simplified 3-nap MSLT (0.860, 95% CI 0.817-0.904; P0.05), whereas no significant difference was observed between the standard 5-nap MSLT and the simplified 4-nap MSLT (0.876, 95% CI 0.834-0.918; P0.05). Consequently, performing only the first 4 naps was sufficient for diagnosing narcolepsy type 1. Conclusion:The simplified 4-nap MSLT, specifically the first to fourth naps, may be used for the diagnosis of narcolepsy type 1.

Glycosylation plays an important role in tumorigenesis and development. Mucoprotein-1 (MUC1), a transmembrane glycoprotein, is overexpressed in a variety of malignant tumors. The biochemical characteristics of tumor-specific short chain O-glycosylation (such as Tn/sialyl Tn (STn) antigens) are significantly different from those of normal tissue MUC1, which provides a molecular basis for precision diagnosis and treatment of tumors. This article systematically reviews the molecular design, clinical transformation progress and technical bottleneck of three types of probes targeting MUC1 glycosylation epitopes in tumors, including aptamers, peptides and monoclonal antibodies, focusing on their tumor uptake efficiency, targeting specificity and the potential of diagnosis and treatment integration, so as to provide theoretical basis for optimizing the clinical transformation path of MUC1 targeting probes.

Objective:To investigate the relationship between the single nucleotide polymorphisms (SNP) rs174575 and rs2845574 in the fatty acid desaturase 2 ( FADS2) gene and gestational diabetes mellitus (GDM). Methods:A total of 1 514 pregnant women who visited West China Second University Hospital, Sichuan University, between January 1, 2013, and December 31, 2021, were enrolled in this study. Among them, 583 were diagnosed with gestational diabetes mellitus (GDM group), and 931 had normal pregnancies (control group). The SNPs rs174575 and rs2845574 in the FADS2 gene were analyzed using Sanger DNA sequencing. Plasma levels, insulin (INS), apolipoprotein A1 (apoA1) and apolipoprotein B (apoB) levels were measured using enzymatic methods, chemiluminescence and immunoturbidimetry. This study was approved by Medical Ethics Committee of the West China Second University Hospital, Sichuan University (Ethics No. 2020-036). Results:① The main type of genotype at the rs174575 C/G and rs2845574 C/T polymorphic sites were CC in both GDM and control groups. No statistically significant differences were observed between the GDM and control groups regarding the genotype frequencies or allele frequencies of rs174575 and rs2845574 sites ( P>0.05). ② Among the GDM group, individuals with the GG genotype at the rs174575 site had lower plasma HDL-C levels compared to those with the CC genotype ( P<0.05), and had higher atherogenic indices (AI) than CC and CG genotype ( P<0.05; P<0.05). Individuals with the TT genotype at the rs2845574 site had higher AI than CT genotype ( P<0.05). Among the control group, individuals with the GG genotype had lower diastolic blood pressure (DBP) compared to those with the CC genotype ( P<0.05). ③ Additional subgroup analysis demonstrated that the rs174575 polymorphism was associated with AI levels in obesity subgroup of GDM, TG levels in non-obese subgroup of control and DBP levels in obese subgroup of control ( P<0.05; P<0.05; P<0.05). Conclusion:The FADS2 rs174575 and rs2845574 polymorphisms in GDM patients were associated wit HDL-C and AI levels, and the FADS2 rs174575 polymorphisms was also associated with DBP levels in normal pregnant women. The AI and DBP levels have BMI-dependent effect.

In this paper, a preliminary stress/strain analysis of the design structure of a nickel-titanium alloy patent foramen ovale occluder is conducted with the finite element simulation analysis method. In the analysis, solid structure modeling is carried out on three different specifications of domestic patent foramen ovale occluders. Referring to the test method of fatigue performance in inspection standard YY/T 1553-2017, an initial installation deformation is applied to the model, and then the fatigue displacement of 2 mm is applied to the sample to make the model fatigue deformation. The fatigue safety factors of each type of occluder are obtained by strain simulation analysis. The results indicate that the minimum fatigue safety factors of the three specifications of domestic patent foramen ovale occluders are 2.09, 2.35 and 2.06 respectively, which all meet the design of fatigue safety factor greater than 1. Among them, 1818 and 3030 specifications of patent foramen ovale occluders have close values in minimum fatigue safety factors, and both are lower than that of 1825 model. Therefore, it is recommended to carry out physical fatigue tests on both 1818 and 3030 specifications to further verify the fatigue performance of the products.
Finite Element Analysis ; Titanium ; Nickel ; Alloys ; Foramen Ovale, Patent ; Materials Testing ; Septal Occluder Device ; Stress, Mechanical

Objective:A mineralized gelatin methacryloyl/hyaluronic acid methacryloyl (GelMA/HAMA) double network hydrogel was constructed, its performance was characterized, and its cell compatibility was studied.Methods:The hydrogel was constructed by photocrosslinking technology, and the biomimetic mineralized hydrogel was prepared by alternating mineralization with calcium and phosphorus solution. The hydrogel was mineralized for three times, for 24 h each time. The control groups were the non-mineralized groups, named the GelMA-0 group and GelMA/HAMA-0 group, respectively. The experimental groups were the mineralized treatment groups. The GelMA hydrogel and GelMA/HAMA double network hydrogel mineralized for 1, 2 and 3 times were named the GelMA-1, 2 and 3 group and GelMA/HAMA-1, 2 and 3 group, respectively. The microstructure of the mineralized hydrogel was characterized by scanning electron microscope and energy dispersive X-ray spectroscopy. The chemical composition of the mineralized hydrogel was characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The mineralization rate of the mineralized hydrogel was evaluated by the ashing method. The compressive strength of the mineralized hydrogel was evaluated by a compression test. The cell compatibility of bone marrow mesenchymal stem cells (BMSCs) on the mineralized hydrogel surface was evaluated by a cell counting kit-8 assay and living/dead cell staining experiment. The datas were analyzed by one-way analysis of variance and Tukey test.Results:With the increase in the number of mineralization cycles, the mineralized layer gradually thickened, and the mineral layer on the cross section of the hydrogel uniformly penetrated into the interior of the hydrogel, with the amount of internal mineral deposition increased. The microstructure of the hydrogel and the distribution of inorganic particles also changed. The surface of the GelMA-3 group and the GelMA/HAMA-3 group contained Ca and P elements, and the distribution was consistent. The inorganic particles generated by mineralization may be immature hydroxyapatite (HAP) crystal precursors. To further verify the chemical composition of inorganic particles, the GelMA-0 and 3 groups as well as the GelMA/HAMA-0 and 3 groups of hydrogels showed GelMA amide Ⅰ, Ⅱ and Ⅲ bands. The GelMA-3 group and GelMA/HAMA-3 group hydrogels contained phosphate, and the diffraction peaks confirmed that the inorganic particles are mainly HAP crystal precursors with low crystallinity. The mineralization rates of the GelMA-1, 2 and 3 groups were (12.48±1.06)%, (21.12±0.62)% and (27.31±0.45)%, while those of the GelMA/HAMA-1, 2 and 3 groups were (15.54±1.03)%, (23.39±0.25)% and (32.26±0.62)%, and the compressive elastic modulus of the GelMA-0, 1, 2 and 3 groups were (69.01±1.04, 91.76±2.05, 105.16±2.95, 131.65±2.21) kPa, and those of the GelMA/HAMA-0, 1, 2 and 3 groups were (270.76±4.56, 347.47±4.60, 388.98±6.96, 430.6±15.47) kPa. Under the same cyclic mineralization times, the mineralization rates and compressive elastic modulus of the GelMA/HAMA double network hydrogel were significantly higher than those of the GelMA hydrogel (all P<0.01). The cell proliferation rates of BMSCs on the GelMA/HAMA-0, 1, 2 and 3 hydrogel surfaces were (49.80±3.38)%, (52.32±1.28)%, (58.00±4.64)% and (62.46±2.74)% on the first day of culture, (58.86±3.36)%, (58.26±3.45)%, (73.08±2.61)% and (76.40±3.45)% on the third day of culture, and (85.89±4.23)%, (90.75±3.21)%, (103.35±4.11)% and (113.42±3.40)% on the fifth day of culture. The cell proliferation rates of the GelMA/HAMA-3 group were significantly higher than those of GelMA/HAMA-0 and 1 groups (all P<0.01). Living/dead cell staining experiment showed that BMSCs on the surface of the GelMA/HAMA-0, 1, 2 and 3 groups were dominated by living cells on the third and fifth days of culture. Conclusions:The mineralized GelMA/HAMA double network hydrogel was constructed, which significantly improved the mineralization rate, mechanical performance and cell compatibility of the biomimetic mineralized hydrogel.

In vivo, cells exist within the mechanical microenvironment of the extracellular matrix (ECM), and their biological processes are regulated by various mechanical factors. However, existing technology limits the direct study of the interaction between cells and ECM in vivo. Using hydrogel to mimic the natural ECM and to construct a suitable mechanical microenvironment for isolated cells, which indirectly reflects the cell-ECM interactions in real organisms through in vitro studies. Thus, in this review, the effects of mechanical factors in hydrogel on different types of cells were summarized, and the development of cell mechanical detection technology using hydrogel as carriers was introduced. Moreover, the future work of using hydrogel to study cell mechanical behavior and related detection technology, as well as standardized preparation, was discussed.