ObjectiveCerebral ischemic injury triggers a complex pathological cascade characterized by excessive reactive oxygen species (ROS) accumulation, persistent oxidative stress, and sustained neuroinflammation in the injured brain microenvironment. These events collectively drive mitochondrial dysfunction, microglial overactivation, pro-inflammatory cytokine release, and progressive neuronal apoptosis, ultimately leading to severe and irreversible neurological deficits. However, conventional therapeutic strategies face critical limitations, including poor blood-brain barrier penetration, insufficient local drug concentration, uncontrolled drug release, and off-target systemic side effects. To address this pathological process, we rationally designed and fabricated an injectable ROS-responsive hydrogel loaded with polydopamine nanoparticles (PDA NPs) for spatiotemporally controlled antioxidation, anti-inflammation, and neuroprotection in the ischemic injury microenvironment. The present study aimed to systematically characterize the physicochemical properties, ROS-responsive drug release behavior, biocompatibility, and neuroprotective efficacy of this composite hydrogel system in vitro. MethodsPDA NPs were fabricated via oxidative self-polymerization. The ROS-responsive hydrogel was cross-linked using N1-(4-boronobenzyl)-N3-(4-boronophenyl)-N1,N1,N3,N3-tetramethylpropane-1, 3-diaminium (TSPBA) and polyvinyl alcohol (PVA). Morphology, particle size, Zeta potential, and structure of PDA NPs were characterized by dynamic light scattering (DLS), Zeta potential analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Microstructure, rheological properties, shear-thinning behavior, and ROS-triggered release profiles of the hydrogel were examined by SEM and rheometry. Biocompatibility was evaluated using HT22 mouse hippocampal neurons with CCK-8 and live/dead staining. An oxygen-glucose deprivation/reoxygenation (OGD/R) model was established to simulate ischemic injury in vitro. ROS levels and neuronal apoptosis were detected by DHE staining and TUNEL assay. Microglial polarization and pro-inflammatory cytokine expression were analyzed using immunofluorescence and RT-qPCR in BV-2 microglia. Transwell co-culture was used to verify the indirect neuroprotection mediated by modulated microglia. ResultsCharacterization results confirmed that the as-prepared PDA NPs were monodispersed spherical nanoparticles with uniform diameter and negative surface potential, demonstrating favorable dispersibility and robust ROS-scavenging activity. The TSPBA-PVA hydrogel exhibited a highly porous interconnected network, suitable mechanical strength, and obvious shear-thinning behavior, supporting its application as an injectable implant. More importantly, the hydrogel displayed typical ROS-responsive degradation and on-demand PDA NP release in a ROS-concentration-dependent manner. In vitro cellular experiments demonstrated that the PDA NP-loaded hydrogel possessed excellent biocompatibility with HT22 cells. In the OGD/R model, the hydrogel significantly reduced intracellular ROS accumulation and markedly suppressed neuronal apoptosis. Furthermore, the composite hydrogel effectively redirected BV-2 microglia from the pro-inflammatory M1 toward the anti-inflammatory M2 phenotypes, downregulated the expression of pro-inflammatory cytokines including TNF-α, IL-1β, and IL-6, and reduced inflammatory damage. Transwell co-culture assays further validated that M2-polarized microglia mediated by the hydrogel significantly enhanced the survival of OGD/R-injured HT22 neurons and attenuated apoptosis. ConclusionIn this study, we successfully developed a novel injectable ROS-responsive hydrogel loaded with PDA NPs for synergistic antioxidative and anti-inflammatory neuroprotection. This intelligent hydrogel system enables ROS-triggered on-demand release of PDA NPs, efficiently scavenges excessive ROS, inhibits oxidative stress injury, modulates microglial polarization, and suppresses neuroinflammation, thereby exerting robust neuroprotective effects in vitro. This biomaterial platform provides a promising strategy for the targeted and controlled delivery of bioactive nanomaterials in the central nervous system diseases and establishes a solid experimental foundation for the development of in situ injectable therapies for ischemic brain injury.

AIM To study the effect of Zuogui Pills on improving ovarian function in rats with premature ovarian failure(POF)by regulating autophagy.METHODS Seven rats were randomly selected as the blank group,and the remaining rats were injected with cisplatin(4.0 mg/kg)intraperitoneally to establish POF model.The success of the model was evaluated by observing the changes of estrous cycle.Twenty-one successful model of rats were randomly divided into model group and estradiol group(0.01 mg/mL)and Zuogui Pills group(1.85 g/kg),with 7 rats in each group,the drug was administered continuously for 21 days.Serum E2,FSH and LH levels were detected by ELISA;HE staining was used to observe the pathological morphology of ovarian tissue;immunohistochemical(IHC)method was used to detect the protein expressions of LC3B,SIRT1 and FoxO1 in ovarian tissues;RT-qPCR method was used to detect the mRNA expressions of LC3B,Beclin-1 and Atg5 in ovarian tissues;the protein expressions of SIRT1,FoxO1 and Ac-FoxO1 in ovarian tissue was detected by Western blot.RESULTS Compared with the blank group,the ovarian index of the model group decreased(P＜0.01);serum FSH and LH levels increased(P＜0.01)and E2 level decreased(P＜0.01);the structure of ovary is disordered,especially atresia follicle;the mRNA expressions of LC3B,Beclin-1 and Atg5 in ovarian tissue increased(P＜0.01),while the protein expressions of LC3B and Ac-FoxO1 increased(P＜0.01),while the protein expressions of SIRT1 and FoxO1 decreased(P＜0.01).Compared with the model group,the ovarian index of rats in estradiol group and Zuogui Pills group increased(P＜0.01);serum FSH and LH levels decreased(P＜0.01)and E2 level increased(P＜0.01);the number of primordial follicles in ovary increased and the number of atresia follicles decreased;the mRNA expressions of LC3B,Beclin-1 and Atg5 in ovarian tissue decreased(P＜0.01),while the protein expressions of LC3B and Ac-FoxO1 decreased(P＜0.01),while the protein expressions of SIRT1 and FoxO1 increased(P＜0.01).CONCLUSION Zuogui Pills may inhibit autophagy by activating SIRT1/FoxO1 signaling pathway,thus improving the pathological state of POF rats,regulating the level of sex hormones in rats,restoring endocrine balance,enhancing ovarian reserve function,promoting the normal development of follicles and delaying the progress of POF.

Lentiviral vectors(LVs)are key gene delivery tools for integrating target genes into the host genome,but they may also pose risks of insertional mutagenesis.The vector copy number(VCN)in cells is critical for determining the safety of gene modification.However,the reliability and accuracy of its quantification process are influenced by multiple factors.Developing cell reference materials with specific vector copy numbers represents a viable approach to enhance the reliability and consistency of measurement results,enabling quality control of the quantification process and traceability of outcomes.However,the preparation of such reference materials faces challenges in cell sample design,preparation protocols,and advanced quantification techniques.In this study,T lymphocyte cell line Jurkat-based reference materials with LV gene copy numbers of 1 and 2 copy/cell were developed.A high-precision duplex digital polymerase chain reaction(dPCR)method was established to quantify the LV gene and endogenous genes simultaneously.Additionally,the results of dPCR were cross-validated through next-generation sequencing and flow cytometric analysis.Ultimately,confocal microscopy characterization results showed that the developed cell reference materials had intact morphology.The quantification result of VCN-1 was(1.07±0.11)copy/cell,and that of VCN-2 was(2.09±0.21)copy/cell.These cell reference materials demonstrated compliance with stability and homogeneity requirements,and could be applied for quality control throughout the VCN measurement workflow and metrological traceability,improving the accuracy,comparability,and validity of copy number measurements.

Objective To construct an aptamer-functionalized carboxylated graphene oxide(CGO)fluo-rescent sensor to achieve highly sensitive and specific detection of ketamine(KET)and its metabolite norketamine(NK)using an aptamer capable of simultaneously recognizing KET and NK.Methods A specific aptamer for simultaneous recognition of KET and NK was screened using graphene oxide-sys-tematic evolution of ligand by exponential enrichment(GO-SELEX)and molecular docking tech-niques.The aptamer,labeled with Cy5 fluorescence,was chemically conjugated to CGO to construct an aptamer-functionalized CGO fluorescent sensor.By optimizing detection conditions,including the mass concentration of CGO,aptamer concentration,reaction temperature,and incubation time,quantita-tive analysis of the target analytes was achieved using the ratio of fluorescence intensity changes be-fore and after target addition.The stability of the sensor in biological matrices was evaluated by moni-toring fluorescence intensity changes over incubation time in blank blood and urine,in comparison with the traditional physical adsorption-based CGO fluorescent sensor.Spiked recovery experiments in blank blood and urine were conducted to compare performance with that of HPLC-MS/MS.Results A specific aptamer A5 was selected and chemically conjugated with CGO to construct the aptamer-functionalized CGO fluorescent sensor.Under optimized conditions,the proposed fluorescent sensor ex-hibited a linear detection range of 1.0-5.0 ng/mL for KET,with a limit of detection(LOD)of 0.86 ng/mL;while for NK,the linear detection range was 1.0-5.0 ng/mL,with an LOD of 0.70 ng/mL.Com-pared with the CGO fluorescent sensor constructed via physical adsorption,this sensor demonstrated greater stability in blood and urine.The spiked recovery rates of KET and NK in blank blood and urine ranged from 81.50%to 110.03%,exhibiting detection performance comparable to that of HPLC-MS/MS.Conclusion The aptamer screening method offers a novel approach for selecting aptamers tar-geting drugs and their metabolites.The constructed aptamer-functionalized CGO fluorescent sensor pro-vides an efficient and reliable strategy for the high-performance detection of KET and NK.

Aim To elucidate the underlying mecha-nism by which total triterpenoids extracted from Hove-nia dulcis(H-TP)enhance the sensitivity of A549/DDP cells to cisplatin.Methods The ARE-Nrf2 lu-ciferase reporter assay was applied to investigate the impact of H-TP on Nrf2 expression.Western blot was used to detect the protein levels of Keap-1/Nrf2/HO-1,Nrf2-GPX4 signaling pathway,apoptosis-related proteins of Bcl-2 and Bax.Further validation of its effects on Nrf2 was conducted by using Nrf2 activator/inhibitor.Results H-TP could enhance the sensitivi-ty of A549/DDP cells to cisplatin by modulating the expression of apoptosis-related proteins Bax and Bcl-2,inhibiting the Keap-1/Nrf2/HO-1/GPX4 signating pathway in A549/DDP cells,and inducing ferroptosis.Conclusion H-TP enhances the sensitivity of A549/DDP cells to cisplatin by inducing the Nrf2-mediated ferroptosis pathway.

Cyclic GMP-AMP synthase(cGAS)is a congenital immune sensor that can recognize cytoplasm abnormal dsDNA.By catalyzing the second messenger cyclic GMP-AMP(cGAMP)formation,it activates stimulator of interferon genes(STING),releases type Ⅰ interferon and inflammatory cytokines,activates the host immune response,and participates in cerebral ischemia reperfusion injury(CIRI)cascade reaction.This article reviews the research progress of the mechanism of cGAS-STING signaling pathway participation in CIRI,hoping to provide ideas for its treatment.

BACKGROUND:The cryopreservation technology enables tissues/cells to be stored for a long time in a low-temperature environment while maintaining the integrity of their activity and function,which is of great significance for the construction of cell therapy,tissue engineering and biological sample banks.Cryoprotective agents often contain dimethyl sulfoxide and serum.To avoid the toxic side effects of dimethyl sulfoxide,the complexity of serum components and immune responses,although some finished cryoprotective agents have been marketed,they are faced with many difficulties such as high cost and limited application.Therefore,there is an urgent need to develop a cryoprotective agent with clear components and the ability to solve the above problems.OBJECTIVE:To evaluate the effects of a novel cryoprotectant on cryopreservation efficiency of different tissue and cell sources.METHODS:By applying the novel cryoprotectant as an experimental group with the commercially available and widely used cryoprotectant(control group)to umbilical cord Wharton's jelly tissue,umbilical cord mesenchymal stem cells,umbilical cord blood/peripheral blood mononuclear cells,NK and CIK cells,comparative analyses were conducted in terms of cell morphology,number,viability,surface markers,differentiation potential,and cell-killing toxicity assay before cryopreservation and after resuscitation thawing.We confirmed the cryopreservation effect of the new cryoprotectant and its potential application value.RESULTS AND CONCLUSION:(1)The novel cryoprotectant facilitated the normal growth of cryopreserved Wharton's jelly tissue upon recovery,exhibiting mesenchymal stem cell morphology.No significant differences were observed between the experimental and control groups in terms of cell recovery rate,surface markers,and differentiation potential.(2)There was no significant difference in the number and viability of cells between the experimental group and the control group after cryopreservation of cord blood/peripheral blood mononuclear cells,and the cryo-resuscitated cell numbers and viability of derived NK cells/CIK cells did not show significant difference between the experimental and control groups.(3)For NK cells derived and differentiated from cord blood/peripheral blood mononuclear cells,there was no significant difference in the proportion of CD56+CD16+cell subpopulations between the experimental group and the control group.For CIK cells derived and differentiated from cord blood/peripheral blood mononuclear cells,there was no significant difference in the proportions of CD3+CD8+and CD3+CD56+cell subpopulations between the experimental group and the control group.(4)In terms of cytotoxicity testing,when the effective-target ratio of immune cells and melanoma cell line Mel624 was 20:1,whether it was NK cells/CIK cells derived from cord blood or peripheral blood mononuclear cells,there was no significant difference in the tumoricidal activity of cells between the experimental group and the control group.These findings suggest that the novel cryoprotectant can replace existing commercially available and widely used cryoprotectants,and is applicable to Wharton's jelly tissue,umbilical cord mesenchymal stem cells,umbilical cord blood/peripheral blood mononuclear cells,as well as NK and CIK cells,providing a solid technical foundation for the scaling,standardization,and commercialization of universal cryoprotectants.

Objective To investigate the occurrence of hemodialysis events in patients who received maintenance hemodialysis in outpatient setting in Liangshan Yi Autonomous Prefecture of Sichuan Province,and provide basis for the formulation of infection prevention and control strategies in this area.Methods Based on the standards from Center for Disease Control and Prevention-National Healthcare Safety Network(CDC-NHSN)as well as the WS/T 312-2023 standards,four public hospitals(two secondary and two tertiary hospitals)in three counties and one city of Liangshan Yi Autonomous Prefecture were selected,and prospective surveillance method was adopted.A total of 826 patients(n=8 675 cases)who received maintenance hemodialysis on the first two working day of each month from March 2024 to March 2025 were surveilled.Data were collected with standardized form by infection control teams in dialysis centers.Statistical analysis was conducted.Results During the surveillance period,the incidence of hemodialysis events was 5.15％(447/8 675).The incidence(16.67％,36/216)and mortality(10.00％,4/40)of hemodialysis events in patients with non-tunneled catheters were the highest among patients with all types of ac-cess.Patients with tunneled-catheters had the highest hospitalization rate(42.86％).Systemic use of antimicrobial agents accounted for 82.33％(368/447).Upper respiratory tract infection was the main infection(38.32％).In-fection at the puncture site of vascular access accounted for 16.78％(75/447).Four cases(0.89％,4/447)had positive blood culture.Conclusion Systemic antimicrobial use and infection at vascular access puncture site is the most frequent events in patients who receive maintenance hemodialysis in outpatient setting in Liangshan Yi Autono-mous Prefecture of Sichuan Province.Patients with non-tunneled catheters have the highest rate of hemodialysis events.

Aim To elucidate the underlying mecha-nism by which total triterpenoids extracted from Hove-nia dulcis(H-TP)enhance the sensitivity of A549/DDP cells to cisplatin.Methods The ARE-Nrf2 lu-ciferase reporter assay was applied to investigate the impact of H-TP on Nrf2 expression.Western blot was used to detect the protein levels of Keap-1/Nrf2/HO-1,Nrf2-GPX4 signaling pathway,apoptosis-related proteins of Bcl-2 and Bax.Further validation of its effects on Nrf2 was conducted by using Nrf2 activator/inhibitor.Results H-TP could enhance the sensitivi-ty of A549/DDP cells to cisplatin by modulating the expression of apoptosis-related proteins Bax and Bcl-2,inhibiting the Keap-1/Nrf2/HO-1/GPX4 signating pathway in A549/DDP cells,and inducing ferroptosis.Conclusion H-TP enhances the sensitivity of A549/DDP cells to cisplatin by inducing the Nrf2-mediated ferroptosis pathway.