ObjectiveThis study aims to investigate the regulatory effects of microcapsules with different matrix stiffness on the survival, proliferation, adhesion, and osteogenic differentiation of mesenchymal stem cells (MSCs), to further explore the relationship between matrix stiffness and MSCs osteogenic behavior, and to evaluate the in vivo histological responses and osteogenic-related protein expression of the microcapsules using an animal subcutaneous implantation model. MethodsIn this study, three-dimensional carbon nanofiber (CNF)/sodium alginate (SA) microcapsules with different matrix stiffness were constructed. By adjusting the CNF content, three groups of microcapsules with stiffness values of 27.05, 35.90, and 52.40 kPa were prepared, and their physicochemical properties, including morphology, mechanical properties, particle size, chemical structure, and degradation properties, were characterized. The effects of these microcapsules with different stiffness on the survival, adhesion, and osteogenic differentiation of MSCs were evaluated. Live/dead staining was used to observe cell survival and distribution in the microcapsules, while alkaline phosphatase (ALP) activity and the expression of osteopontin (OPN) and osteocalcin (OCN) were examined to assess osteogenic differentiation. Immunofluorescence staining was further performed to observe the expression of Yes-associated protein (YAP) and integrin β1 under different stiffness conditions. In addition, a rat subcutaneous implantation model was used to evaluate the in vivo tissue compatibility of the microcapsules. Histological staining and immunohistochemical analysis were carried out to examine local tissue responses and the expression of osteogenic-related proteins. ResultsThe results showed that all three groups of microcapsules exhibited regular and uniform morphology and similar particle size, and all groups showed good degradability. Except for the differences in mechanical properties, no obvious differences were found in the other physicochemical properties among the three groups. Live/dead staining indicated that all groups of microcapsules had good cytocompatibility. MSCs in the low-stiffness group were mostly round, whereas cells in the medium- and high-stiffness groups showed more obvious spreading. Higher matrix stiffness was more favorable for MSC adhesion, growth, and survival. ALP staining and quantitative analysis showed that ALP activity increased significantly with increasing matrix stiffness. The expression of the osteogenic-related proteins OPN and OCN also increased with increasing stiffness, and the high-stiffness group showed the strongest positive signals. Immunofluorescence results further indicated that YAP and integrin β1 fluorescence signals tended to increase in MSCs with increasing matrix stiffness, suggesting that matrix stiffness may influence MSC osteogenic differentiation through stiffness-related cell adhesion and mechanotransduction. In vivo experiments showed that all three groups of microcapsules exhibited good histocompatibility after subcutaneous implantation, although different degrees of degradation and local tissue response were observed. Immunohistochemical analysis showed that the expression levels of OPN and OCN increased with increasing matrix stiffness, and the high-stiffness group exhibited higher expression of these osteogenic-related proteins. ConclusionCNF endows SA microcapsules with tunable matrix stiffness. While maintaining good biocompatibility, the high-stiffness microenvironment can effectively promote the adhesion and osteogenic differentiation of MSCs, accompanied by increased ALP activity and enhanced OPN and OCN expression. The increased YAP and integrin β1 fluorescence signals in the high-stiffness group further indicate that matrix stiffness is closely related to cellular mechanical responses. These findings provide a three-dimensional cell carrier with potential application value for MSC delivery and bone tissue regeneration based on mechanical microenvironment regulation.

ObjectivePeripheral nerve injury is a common clinical condition that can impair the regulatory function of target organs, leading to functional disability; severe injuries may even result in lifelong disability. Therefore, how to effectively promote the morphological and functional reconstruction of injured peripheral nerves has become a critical scientific issue that urgently needs to be addressed. This study biomimicked the highly oriented structure and electrophysiological properties of peripheral nerves and investigated the feasibility and effectiveness of combining electrical stimulation (ES) with oriented conductive substrates for the repair of injured peripheral nerves at the cellular level. MethodsPolydimethylsiloxane (PDMS) substrates with oriented microgroove structures of varying widths (0, 5, 10, and 20 μm) were fabricated using silicon wafers with micropatterned grooves as templates. Graphene-based conductive patterned substrates (GCPSs) with oriented microgrooves were then constructed via soft lithography and designated as GCPS 0, GCPS 5, GCPS 10, and GCPS 20 according to the groove width. The GCPSs were prepared from collagen/polycaprolactone (PCL) matrices containing 1.0 wt% graphene, and their morphology, wettability, and conductivity were characterized. Mesenchymal stem cells (MSCs) viability, proliferation, adhesion, and orientation on the substrates were evaluated before ES treatment. Then, ES at a frequency of 2 Hz and field strengths of 10, 20, or 50 mV/cm were applied to the cells for 10 min daily, over 3 or 7 consecutive days. Neural differentiation was assessed by morphological observation, immunofluorescence staining, and analysis of neural lineage-related markers. ResultsThe oriented microgroove PDMS substrates supported long-term MSCs growth, guided cells to align along the groove direction, and promoted a morphological transition toward neural-like cells, exhibiting the capacity to induce MSCs differentiation toward the neural lineage. Microgroove structures effectively guided the alignment of MSCs and promoted the development of a more elongated, neural-like morphology, with the most pronounced morphological changes observed on grooves of 10 and 20 μm in width. Meanwhile, the incorporation of graphene endowed the GCPSs with favorable electrical conductivity, though the groove width did not significantly affect the conductive performance. The GCPSs showed good cytocompatibility with MSCs, and cell proliferation on these substrates exhibited a time-dependent pattern, with no significant effect observed from groove width. The inductive effect of ES combined with GCPSs on MSCs differentiation toward specific neural lineages was co-regulated by ES intensity (0, 10, 20, and 50 mV/cm) and microgroove width. ES at 10 mV/cm and 20 mV/cm promotes MSCs differentiation toward neurons on microgrooved substrates of various widths (5, 10, and 20 μm); under the same ES intensities, microgrooves with widths of 5 μm and 10 μm are more favorable for MSCs differentiation toward glial cells/SCs. Notably, low-intensity ES (10 or 20 mV/cm) combined with GCPS 10 significantly enhanced the neural differentiation of MSCs. Neurotrophic factor secretion levels by MSCs cultured on various GCPS substrates after 3 d of ES application was further detected. There were no significant differences in nerve growth factor‑β (NGF‑β) and brain-derived neurotrophic factor (BDNF) concentrations among the GCPS 5, GCPS 10, and GCPS 20 substrates, and these levels were not affected by variations in ES intensity. Under ES at 10 mV/cm, the glial cell line-derived neurotrophic factor (GDNF) concentration in each GCPS substrate was higher than that in the corresponding non-ES group on the same substrate. However, as ES intensity increased, the GDNF concentration decreased to varying degrees. ConclusionThis study demonstrates that the combined strategy of “oriented topographical structure+ES” can effectively promote the neural differentiation of MSCs and holds promise for accelerating the repair process of peripheral nerve injuries.

ObjectiveTo examine the influencing mechanisms and regional differences in accessible facility utilization behavior among residents in eastern and central-western China. MethodsData were collected through the online questionnaire administered to residents across China using snowball sampling. Descriptive analysis and chi-square tests were conducted to compare the basic characteristics of respondents between the two regions. Welch's t test was used to compare accessible facility utilization behavior and its influencing factors. Multigroup structural equation modeling (SEM) was applied to compare the influencing mechanisms of accessible facility utilization behavior between eastern and central-western China. ResultsA total of 1 039 valid responses were obtained, including 604 from the eastern region and 435 from the central-western region. Residents in eastern regions scored significantly higher than those in central-western regions on both facility-seeking (t = 4.057, P < 0.001) and actual-using (t = 4.551, P < 0.001) behavior. The structural equation models for both regions showed identical and satisfactory goodness-of-fit indices (GFI = 0.950, AGFI = 0.932, IFI = 0.947, CFI = 0.947, RMSEA = 0.028), and all measurement and structural invariance tests met the recommended criteria. Facility configuration showed no significant direct effect on utilization behavior in eastern China, whereas a negative direct effect was observed in central-western China (β = -0.171, P = 0.047), with its influence mainly exerted indirectly through social cognition and user experience. Social cognition and user experience had significant positive effects on utilization behavior (P < 0.001). Meanwhile, social cognition indirectly influences utilization behavior through the mediating path of usage experience. The direct effects of social cognition (β = 0.406) and user experience (β = 0.510) in central-western China were greater than those in eastern China (β = 0.369 and β = 0.335, respectively). The chain mediation effect of "configuration-cognition-experience-behavior" was statistically significant in both regions (P < 0.05), with larger indirect effects observed in central-western China. ConclusionFacility configuration has a limited direct effect on accessible facility utilization, whereas social cognition and user experience play a central role, particularly in central-western China. It is recommended that the construction and renovation of accessible facility be guided by population needs, accompanied by strengthened promotion of accessibility concepts and policies, and that a transition from hardware-oriented construction to service- and management-oriented governance of accessible environments should be promoted in central-western China.

In this study, we constructed a GLP-2R-HEK293 cell line and established a method for the determination of the in vitro biological activity of teduglutide based on HTRF, after optimizing experimental conditions and methodological verification. We also carried out relative potency detection of teduglutide pharmaceutical products using this method. The result showed that there was a quantitative-efficient relationship between the teduglutide activity and cAMP contents in GLP-2R-HEK293 cells, which conformed to four-parameter model. Method verification results of five concentrations of teduglutide (64%, 80%, 100%, 125% and 156%) met the requirements of the General Rules of Chinese Pharmacopoeia, 2020 edition, Volume IV (9401). We then analyzed the relative potency of three batches of teduglutide drug substances and three batches of drug products. The linearity, regression and parallelism of the obtained curves all fit the system suitability requirements. The relative potency of six batches of teduglutide was from 83% to 105%. In summary, the biological activity detection method established in this study was accurate, precise, simple and time-saving, which can be used for quality control of teduglutide pharmaceutical products.

Age-related sarcopenia is a progressive, systemic skeletal muscle disorder associated with aging. It is primarily characterized by a significant decline in muscle mass, strength, and physical function, rather than being an inevitable consequence of normal aging. Despite ongoing research, there is still no globally unified consensus among physicians regarding the diagnostic criteria and clinical indicators of this condition. Nonetheless, regardless of the diagnostic standards applied, the prevalence of age-related sarcopenia remains alarmingly high. With the global population aging at an accelerating rate, its incidence is expected to rise further, posing a significant public health challenge. Age-related sarcopenia not only markedly increases the risk of physical disability but also profoundly affects patients’ quality of life, independence, and overall survival. As such, the development of effective prevention and treatment strategies to mitigate its dual burden on both societal and individual health has become an urgent and critical priority. Skeletal muscle regeneration, a vital physiological process for maintaining muscle health, is significantly impaired in age-related sarcopenia and is considered one of its primary underlying causes. Skeletal muscle satellite cells (MSCs), also known as muscle stem cells, play a pivotal role in generating new muscle fibers and maintaining muscle mass and function. A decline in both the number and functionality of MSCs is closely linked to the onset and progression of sarcopenia. This dysfunction is driven by alterations in intrinsic MSC mechanisms—such as Notch, Wnt/β‑Catenin, and mTOR signaling pathways—as well as changes in transcription factors and epigenetic modifications. Additionally, the MSC microenvironment, including both the direct niche formed by skeletal muscle fibers and their secreted cytokines, and the indirect niche composed of extracellular matrix proteins and various cell types, undergoes age-related changes. Mitochondrial dysfunction and chronic inflammation further contribute to MSC impairment, ultimately leading to the development of sarcopenia. Currently, there are no approved pharmacological treatments for age-related sarcopenia. Nutritional intervention and exercise remain the cornerstone of therapeutic strategies. Adequate protein intake, coupled with sufficient energy provision, is fundamental to both the prevention and treatment of this condition. Adjuvant therapies, such as dietary supplements and caloric restriction, offer additional therapeutic potential. Exercise promotes muscle regeneration and ameliorates sarcopenia by acting on MSCs through various mechanisms, including mechanical stress, myokine secretion, distant cytokine signaling, immune modulation, and epigenetic regulation. When combined with a structured exercise regimen, adequate protein intake has been shown to be particularly effective in preventing age-related sarcopenia. However, traditional interventions may be inadequate for patients with limited mobility, poor overall health, or advanced sarcopenia. Emerging therapeutic strategies—such as miRNA mimics or inhibitors, gut microbiota transplantation, and stem cell therapy—present promising new directions for MSC-based interventions. This review comprehensively examines recent advances in MSC-mediated muscle regeneration in age-related sarcopenia and systematically discusses therapeutic strategies targeting MSC regulation to enhance muscle mass and strength. The goal is to provide a theoretical foundation and identify future research directions for the prevention and treatment of this increasingly prevalent condition.

Background and purpose:In breast cancer surgery,margin status assessment significantly impacts patient prognosis,with positive margins indicating higher recurrence and metastasis risks.Ensuring complete tumor resection is thus critical for surgical success.Indocyanine green(ICG)has garnered attention for its potential real-time imaging of breast cancer lesions under near-infrared light.This study employed ICG for intraoperative assessment of breast cancer lesion margin status and further explored the possibility of optimizing the safe margin distance surround the lesion in normal breast tissue.Methods:Clinical data of patients admitted to the Department of Thyroid and Breast Surgery,the Fourth Affiliated Hospital of Anhui Medical University(Affiliated Chaohu Hospital),from December 2021 to September 2022 were collected.A retrospective clinical study was conducted on breast cancer patients who were randomly assigned to either the ICG group or the conventional surgery group.Two to three hours before surgery,patients in the ICG group received a peripheral intravenous injection of 0.5 mg/kg ICG.Intraoperative fluorescence imaging was performed on the specimen before and after resection,as well as on the residual cavity.Near-infrared fluorescence imaging equipment was used to quantitatively measure fluorescence intensity of resected lesions at 4 directions(12,3,6,and 9 o'clock)and detect fluorescence in the residual cavity after lesion removal.Specimens were promptly sent to the pathology department for pathological examination,and safety margins of normal breast tissue in the 4 directions were recorded.The Strengthening the Reporting of Observational Studies in Epidemiology(STROBE)checklist was followed for this study.This study was approved by the Ethics Committee of the Fourth Affiliated Hospital of Anhui Medical University(Affiliated Chaohu Hospital)(No.KYXM-202310-46).Results:This study included 50 breast cancer patients,with 24 in the ICG group and 26 in the traditional surgery group.In the ICG group,fluorescence signals were detected at all lesion sites.Specifically,fluorescence density values at the lesion center,margin,and surrounding normal breast tissue were measured as 251.08±10.73,208.08±19.74,and 156.76±16.47,respectively,showing a gradual decrease from center outward with statistically significant differences(P＜0.05).Additionally,fluorescence ratios between the lesion center and margin,and center and surrounding normal tissue,were 1.22±0.13 and 1.62±0.19,respectively.After resection,abnormal fluorescence was observed in 2 of 24 cases in the residual cavity,with 1 case being invasive carcinoma with ductal carcinoma in situ and the other normal breast tissue.Ultimately,this study demonstrated that ICG achieved a sensitivity of 95.9%and a specificity of 97.9%in margin assessment.After specimen resection,the safety margins of normal glandular tissue surrounding the lesion were measured.The safety widths for the ICG group and the concurrent breast cancer surgery group were(8.36±6.42)mm and(15.08±4.75)mm,respectively.This difference was statistically significant(P＜0.05).Conclusion:ICG is a real-time,efficient,and cost-effective tracer that can be used to determine breast cancer margins,with excellent sensitivity and specificity.For early-stage breast cancer patients who are eligible for breast-conserving surgery,this tracer helps to reduce the amount of healthy breast tissue that is removed around the lesion.

Objective To evaluate the effectiveness of different tip positions applied to midline catheters(MC)and provide evidence-based evidence for venous catheter tip positioning in clinical practice.Methods Computerized searches of PubMed,Web of Science,Embase,Cochrane Library,CINAHL,CNKI,Wanfang Database,VIP,and CBM for studies on the effectiveness of applying MC with different tip positions were performed from the time of database construction to July 2024.Meta-analysis was performed using Rev Man 5.3 software after 2 investigators independently screened the studies,extracted the information and evaluated the quality of the included studies.Results A total of 9 studies with 2 302 hospitalized patients were included.The quality evaluation results of the included studies are all B-level.Meta-analysis showed that when the tip of the MC was located in the subclavian vein compared with the tip of the MC in the axillary vein,the rate of total catheter-related complications,phlebitis,blood leakage,infiltration,catheter occlusion,catheter dislocation,and catheter-associated thrombosis were lower,with a statistically significant difference(P＜0.05).When the tip of the MC was located in the subclavian vein compared with the tip of the MC in the axillary vein,the catheter retention time was longer,with a statistically significant difference(P=0.007).The descriptive analysis showed a lower rate of extubation due to complications when the tip of the MC was located in the subclavian vein compared with when the tip was located in the axillary vein(P＜0.05).Conclusion When the tip of the MC is located in the subclavian vein compared to when it is located in the axillary vein,the incidence of total catheter-related complications,phlebitis,blood leakage,infiltration,catheter occlusion,catheter dislocation,catheter-associated thrombosis,and the rate of catheter extractions due to complications were lower,and the catheter was left in place for a longer period of time.Due to the limitations of the quantity and quality of the included studies,more large-sample,high-quality studies are needed to further validate the effectiveness of different tip positions of MC.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.