BACKGROUND:Exosomes are nanoscale extracellular vesicles secreted by various types of cells,with advantages such as high bioavailability,low toxicity,low immunogenicity,and good biocompatibility.However,natural exosomes have certain limitations in clinical therapy.By using bioengineering techniques to modify and engineer exosomes,the engineered exosomes not only improve their original therapeutic effects but also exhibit excellent biostability and targeting specificity,showing great potential for application in the field of tissue repair.OBJECTIVE:To summarize the various strategies for engineering exosomes,including functional loading and surface modification,outline the research progress of engineered exosomes in different tissue repairs,and explore the therapeutic potential of engineered exosomes in tissue repair.METHODS:PubMed database was searched for relevant literature published between 2010 and 2024 using the search terms"engineered exosomes,tissue repair,biomaterials,tissue engineering,wound healing,parenchyma,bone regeneration,cartilage,neural,myocardial,hepatic."Studies that were not closely related to the article's theme,of poor quality,repetitive,or outdated were excluded.A total of 115 articles met the inclusion criteria.RESULTS AND CONCLUSION:(1)Functional loading is used to combine therapeutic molecules with exosomes to obtain additional properties or to enhance the original physiological function of the exosome,among which ultrasonication and extrusion are simple to operate and can obtain higher drug loading capacity at the same time.(2)Surface modification can make exosomes express desired proteins or enhance their targeting,including genetic engineering and chemical modification.Genetic engineering is complicated,poorly reproducible,and the end product is poorly controllable.Chemical modification,on the other hand,is relatively simple and versatile,and is more suitable for designing highly targeted and functionally specific engineered exosomes.(3)Among the techniques for pre-treating cells to obtain engineered exosomes,hypoxic pre-treatment is more widely used because of its simplicity and clearer mechanism,which can activate glycolysis to promote cell proliferation,and regulate the vascular endothelial growth factor receptor signaling pathway through the generation of hypoxia-inducible factors to promote angiogenesis.(4)The function of exosomes is affected by various factors such as cell source,cell state,synthesis process,and extracellular environment.If the engineering strategy is complicated,it is more difficult to ensure the functional consistency of the final engineered exosomes,so the relatively simple and reliable engineering strategy is more suitable for its clinical application.(5)Engineered exosomes combined with biomaterials or scaffolds can be used to treat complex wounds of skin soft tissue,such as infected wounds and diabetic ulcers.This approach enhances exosome delivery and controls their release,promotes tissue repair,controls infection,and regulates the local microenvironment of the wound.(6)A single mechanism of engineered exosomes is often ineffective due to the specificity of the bone tissue fracture,so dual or even multi-functional engineered exosomes are needed to promote fracture repair while anti-inflammatory or remodeling the vascular system.(7)The source of exosomes has a significant impact on neural tissue repair.Exosomes derived from different neural cells promote neural repair through different effects.In addition,the combination of stents and engineered exosomes for traumatic brain injury has obvious advantages,the stent itself provides hemostasis and support,combined with the engineered exosomes itself to promote the repair effect,can obtain better therapeutic effect.(8)In cardiac and hepatic tissue repair,it is needed to develop anti-fibrotic engineered exosomes to resist the abnormal repair of cardiac and hepatic tissues themselves,which will require further research in the future.

BACKGROUND:Dental pulp stem cells,which derived from the dental pulp tissue,are one type of dental-derived mesenchymal stem cells,possess significant properties of self-renewal and multi-lineage differentiation.In recent years,series of researches focus on dental pulp stem cells and their derivatives such as extracellular vesicles,conditioned medium,and decellularized extracellular matrix,those have positive effects on the repair and regeneration of pulp tissue injury,showing an attractive clinical application.OBJECTIVE:To systematically review the researches and applications of dental pulp stem cells and their derivatives in dental pulp tissue engineering.METHODS:Literature searches were conducted in PubMed,China Biology Medicine(CBM),and China National Knowledge Infrastructure(CNKI)databases for articles published from January 2005 to June 2023.The search terms included"dental pulp stem cells,extracellular vesicles,exosomes,apoptotic bodies,conditioned medium,decellularized matrix,regeneration"in Chinese and English.After screening the titles and abstracts,duplicate and irrelevant studies were excluded.Finally,103 studies closely related to dental pulp regeneration were included for review and analysis.RESULTS AND CONCLUSION:Dental pulp stem cells and their derivatives are rich in lots of bioactive factors that can effectively promote odontogenic,angiogenic,and neurogenic differentiation,exhibiting significant potential in the formation of the pulp-dentin complex.However,the clinical translation of dental pulp stem cells and their derivatives still faces several challenges.Future researches should focus on optimizing preparation protocols,elucidating the underlying mechanisms of action,and refining safety assessments to provide novel therapeutic strategies for the repair of dental pulp injury.

BACKGROUND:Currently,treatment method for knee osteoarthritis includes oral medicine,joint cavity drug injection,and physiotherapy,but the curative effect is limited.Existing studies have confirmed that silicon-based bioceramics can promote cartilage and subchondral bone repair and vascular regeneration.OBJECTIVE:To explore the effect of different concentrations of silicon-based bioceramics injected into the knee joint cavity in the treatment of knee osteoarthritis in rats.METHODS:Silicon-based bioceramics-calcium silicate was prepared.Twenty-five SD rats were randomly divided into five groups,with five rats in each group.The healthy group did not receive any intervention,and the modeling group,low-dose calcium silicate group,high-dose calcium silicate group,and saline group used anterior cruciate ligament transection to establish bilateral knee osteoarthritis models.Four weeks after modeling,0.05 mL of 50 and 100 mg/mL calcium silicate solution were injected into the knee joint cavity in the low-dose calcium silicate group and high-dose calcium silicate group,respectively,and 0.05 mL of saline was injected into the knee joint cavity in the saline group,once a week for 4 consecutive weeks.In the fifth week of administration,bilateral knee joint Micro-CT detection,knee joint cartilage hematoxylin-eosin staining,and modified Mankin score were performed.RESULTS AND CONCLUSION:(1)Micro-CT quantitative analysis showed that compared with the healthy group,the volume fraction and number of trabeculae of the medial tibial plateau in the modeling group decreased(P＜0.05),and the separation of trabeculae increased(P＜0.05).Compared with the modeling group,the volume fraction and number of trabeculae of the medial tibial plateau in the low-dose calcium silicate group and the saline group increased(P＜0.05),and the separation of trabeculae decreased(P＜0.05).(2)Hematoxylin-eosin staining showed that the cartilage surface of the healthy group and the low-dose calcium silicate group was relatively smooth and flat,the chondrocytes were evenly distributed,without clustered chondrocytes,the tide line was complete,and the staining was uniform;the cartilage surface of the high-dose calcium silicate group was slightly uneven,the middle and deep cells were disordered,with a small number of clustered chondrocytes,the tide line was discontinuous,and the staining was uneven;the cartilage surface of the saline group and the modeling group was obviously rough,the cells were disordered,with a large number of clustered chondrocytes,the tide line disappeared,and the staining was uneven.The modified Mankin score of the healthy group was lower than that of the high-dose calcium silicate group,the saline group,and the modeling group(P＜0.05).The modified Mankin score of the high-dose calcium silicate group and the low-dose calcium silicate group was lower than that of the saline group and the modeling group(P＜0.05).(3)The results show that calcium silicate knee joint injection has a certain effect in the treatment of knee osteoarthritis.Compared with 100 mg/mL calcium silicate solution,50 mg/mL calcium silicate solution can promote the recovery of subchondral bone and cartilage.

BACKGROUND:Bone remodeling is the biological basis of orthodontic tooth movement.Type 2 diabetes mellitus leads to metabolic changes in the jaw and alveolar bone,so it is hypothesized that tooth mobility characteristics may be altered in a high-sugar environment.OBJECTIVE:To explore the impact of type 2 diabetes mellitus on orthodontic tooth movement in rats within one tooth movement cycle.METHODS:Seventy-two Sprague-Dawley rats were selected.Forty rats were randomly chosen and fed with a high-fat diet to construct a type 2 diabetes mellitus model.Thirty-two rats that were successfully modeled were randomly divided into a type 2 diabetes mellitus group(n=16)and a diabetic orthodontic group(n=16).The remaining 32 rats were randomly divided into a control group(n=16)and an orthodontic group(n=16).The rats in the orthodontic group and the diabetic orthodontic group were equipped with nickel-titanium coil spring orthodontic force application devices to move the unilateral maxillary first molars mesially with a force of 50 g.The rats were anesthetized and sacrificed on the 3rd,7th,14th,and 21st days after orthodontic treatment,and Micro-CT was used to measure the mesial displacement of the first molars and detect the changes in the bone microstructure parameters on the tension side.RESULTS AND CONCLUSION:There were significant differences in the tooth movement distances among the four groups of rats on the 3rd,7th,14th,and 21st days of orthodontic treatment(P＜0.05).There were significant differences in bone mineral density,bone volume fraction and trabecular bone separation on the tension side among the four groups on the 7th,14th,and 21st days of orthodontic treatment(P＜0.05).There were differences in the trabecular thickness among the four groups on the 3rd and 14th days of orthodontic treatment(P＜0.05).The diabetic orthodontic group had the smallest tension-side alveolar bone mineral density,bone volume fraction,and trabecular thickness,and the largest tooth movement distance and trabecular separation on the 21st day of orthodontic treatment.The above results indicate that type 2 diabetes mellitus adversely affects bone microstructural parameters on the tension side in orthodontic tooth movement in rats,suggesting the occurrence of an osteoporotic state.

Objective:To assess the status of undernutrition and appropriate catch-up growth in extremely preterm infants within 24 months of corrected age (CA).Methods:A retrospective cohort study was conducted. A total of 422 extremely preterm infants born at Shenzhen Maternity and Child Healthcare Hospital, Women and Children's Medical Center, Southern Medical University from January 2017 to December 2022 and followed up until 24 months of CA were enrolled. The extremely preterm infants were grouped by gestational age at birth (<25, 25-26, 27 weeks), birth weight (<500, 500-749, 750-999,≥1 000 g), weight for gestational age (large for gestational age (LGA), appropriate for gestational age (AGA), small for gestational age (SGA)) and sex. Weight data within 24 months of CA were collected every 3 months. Nutritional insufficiency, growth rate, and achievement of adequate catch-up growth were analyzed during the period from 0 to 24 months of CA. Z-score method was used to analyze data. Fenton 2013 preterm growth charts (Fenton 2013) were used before 40 weeks of corrected gestational age, and World Health Organization child growth standards (2009) fitted Z-scores were applied from 40 weeks of CA. Changes in weight Z-scores of extremely preterm infants from 0 to 24 months of CA were observed and compared, the occurrence of moderate to severe malnutrition and growth retardation was determined, nutritional insufficiency was assessed, and growth rate as well as the achievement of appropriate catch-up growth were analyzed. The Lambda-mu-sigma method combined with the Z-score fitting model was used to fit and analyze the distribution characteristics of weight percentiles in extremely preterm infants. The Chi-square test was used to compare differences among groups.Results:A total of 422 extremely preterm infants were included, with a gestational age at birth of 26.3(25.4, 27.2) weeks and a birth weight of (880±177) g. Among them, 238 were males and 184 were females; 36 cases (8.5%) were LGA, and 16 cases (3.8%) were SGA. During follow-up within 24 month of CA, 89 cases (21.1%) developed moderate to severe malnutrition. When compared separately among different birth weight and gestational age at birth groups, there had both statistically differences in the incidence of moderate to severe malnutrition ( χ2=42.94 and 9.17, both P<0.05). The incidence was the highest in the birth weight of CA<500 g group and the <25 weeks gestational age at birth group, while it was the lowest in the birth weight of CA≥1 000 g group and the 27 weeks gestational age at birth group in their respective groups. Growth retardation occurred in 5.2% (22/422). However, there had statistically differences in the incidence of growth retardation among different birth weight and gestational age at birth groups, in each grouped time interval ( χ2=21.61 and 4.30, both P<0.05). The proportions of rapid growth were relatively high in the 0-3 months and 3-6 months of CA groups, which were 96 cases (27.4%) and 98 cases (26.6%), respectively. Overall, appropriate catch-up growth was achieved in 341 cases (80.8%) from 0 to 24 months of CA. There had statistically differences in the completion rate of appropriate catch-up growth among different birth weight and gestational age at birth groups ( χ2=23.65 and 7.08, both P<0.05). The completion rate was the highest in the birth weight of CA<500 g group and the <25 weeks of gestational age at birth group, while it was the lowest in the birth weight of CA≥1 000 g group and the 27 weeks of gestational age at birth group. Conclusions:The lower the birth weight and gestational age of extremely preterm infants, the higher the incidence of moderate to severe malnutrition and the lower the achievement rate of adequate catch-up growth within 24 months of CA. The period of 0-6 months of CA is the critical window for catch-up in extremely preterm infants.

ObjectiveTo investigate the material basis of the pathogenesis of cerebral ischemic injury with blood stasis and toxin syndrome and to explore the protective effects of Huayu Jiedu prescription （HYJDP） on neutrophil extracellular trap-related cell death （NETosis） in cerebral ischemic injury following acute cerebral infarction. MethodsSeventy-two Sprague-Dawley （SD） rats were randomly divided into six groups （n=12 per group）： sham operation （Sham） group， blood stasis and toxin model （Model） group， low-， medium-， and high-dose HYJDP groups （HYJDP-L， HYJDP-M， and HYJDP-H； 9， 18， and 36 g·kg^-1， respectively）， and butylphthalide （NBP） group （0.06 g·kg^-1）. Except for the Sham group， rats in all other groups were subjected to carrageenan/dry yeast combined with a modified intraluminal filament method to establish a focal cerebral ischemia model of the middle cerebral artery with blood stasis and toxin syndrome. Neurological function was evaluated at 24 h after modeling using the Zea-Longa neurological deficit score. Cerebral infarction rate was assessed by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Pathological morphology of brain tissue was observed using hematoxylin-eosin （HE） staining. Enzyme-linked immunosorbent assay （ELISA） was used to determine serum levels of interleukin-8 （IL-8）， myeloperoxidase-DNA complexes （MPO-DNA）， and citrullinated histone H3 （CitH3）. Protein expression of phosphorylated phosphatidylinositol 3-kinase （p-PI3K）， protein kinase B （p-Akt）， mammalian target of rapamycin （p-mTOR）， sequestosome 1 （p62）， and CitH3 in brain tissue was detected by Western blot. Immunofluorescence （IF） was used to detect the expression of neutrophil-specific marker Ly6G， CitH3， and neuron-specific nuclear protein （NeuN） in brain tissue. ResultsCompared with the Sham group， neurological deficit scores and cerebral infarction rates in the model group were significantly increased （P<0.01 for both）. HE staining showed varying degrees of neuronal degeneration and necrosis， characterized by blurred neuronal structures， nuclear pyknosis and fragmentation， cytoplasmic dissolution into a vacuolated reticular pattern， and mild glial cell proliferation. ELISA results showed that serum levels of IL-8， MPO-DNA， and CitH3 were significantly increased （P<0.01）. Western blot analysis demonstrated decreased expression of p-PI3K， p-Akt， p-mTOR， and p62， while CitH3 expression was significantly increased （P<0.01）. IF results showed an increased number of NETs⁺ cells and a significant decrease in NeuN⁺ cells （P<0.01）. Compared with the Model group， neurological deficit scores in the HYJDP-H group were significantly decreased （P<0.05）， and cerebral infarction rates in the HYJDP-H and NBP groups were significantly reduced （P<0.01）. HE staining showed that brain tissue damage was markedly alleviated in the HYJDP-H group. ELISA results showed that levels of IL-8， MPO-DNA， and CitH3 were significantly decreased in the HYJDP-M， HYJDP-H， and NBP groups （P<0.01）. Western blot analysis showed that expression of p-PI3K， p-Akt， p-mTOR， and p62 was significantly increased in the HYJDP-H and NBP groups， while CitH3 expression was significantly reduced in all drug intervention groups （P<0.01）. IF results showed that the number of NETs⁺ cells was significantly decreased and the number of NeuN⁺ cells was significantly increased in all drug intervention groups （P<0.01）. ConclusionNETs may be the material basis of the pathogenesis of cerebral ischemic injury characterized by blood stasis and toxin. HYJDP can regulate the PI3K/Akt/mTOR signaling pathway， reduce the release of pro-inflammatory mediators and NETosis-related products， alleviate cerebral ischemic injury caused by autophagy-dependent NETosis， and thereby exert a neuroprotective effect.

Intravascular large B-cell lymphoma(IVLBCL) is a rare and aggressive type of lymphoma with diverse and nonspecific clinical manifestations, often leading to misdiagnosis. This article reports a case of IVLBCL in a middle-aged male patient who initially presented with pulmonary arterial hypertension(PAH). The patient exhibited progressive hypoxemia and PAH, showing poor response to standard PAH therapy. Laboratory tests indicated a hyperinflammatory state and significantly elevated lactate dehydrogenase levels, while imaging revealed diffuse bilateral lung lesions. Random skin biopsy identified atypical B lymphocytes within subcutaneous capillaries, confirming the diagnosis of IVLBCL. Following treatment with the ZR-CHOP regimen, the patient's symptoms and laboratory parameters improved markedly. By reviewing relevant literature, this article systematically outlines the diagnostic and therapeutic process of this case, aiming to provide insights for the clinical recognition of such rare presentations.

To systematically analyzed the reporting status of core elements in publicly available clinical practice guideline(hereafter referred to as "guideline") protocols published domestically and internationally over the past decade, identified existing problems, and provided evidence to inform the standardized writing and publication of future guideline protocols.

Objective: To characterize perioperative dynamic changes in immune-cell phenotypes and inflammatory cytokines in patients undergoing CPB (cardiopulmonary bypass) cardiac surgery, and to explore their associations with postoperative outcomes. Methods: In this prospective cohort study, 120 adult patients who underwent elective cardiac surgery under CPB at West China Hospital from May 2022 to March 2023 were enrolled. Perioperative immune-cell phenotypes and concentrations of 40 inflammation-related cytokines were measured. The primary outcomes were the sequential organ failure assessment (SOFA) score at 24 h after surgery and ΔSOFA (the peak SOFA score within 48 h after surgery minus the preoperative SOFA score). Secondary outcomes included major adverse cardiovascular events (MACE), acute kidney injury (AKI), respiratory failure, severe liver injury, and infection. Results: The mean age of enrolled patients was 57±10 years. Of these, 52% (62/120) were male and 90% (108/120) underwent valve surgery. During the rewarming to the end of CPB, neutrophil counts rapidly increased (7.39×10 /L vs preoperative 3.07×10 /L, P<0.001), with significant upregulation of CD11b (7.30×10 /L vs preoperative 3.05×10 /L, P<0.001) and CD54 (7.15×10 /L vs preoperative 2.99×10 /L, P<0.001). Lymphocyte counts increased at the end of CPB (1.75×10 /L vs preoperative 1.12×10 /L, P<0.001) but decreased significantly at 24 h after surgery (0.59×10 /L vs preoperative 1.12×10 /L, P<0.001). Plasma analysis showed that multiple pro-inflammatory cytokines increased during CPB and remained elevated up to 24 h after surgery; five chemokines and the anti-inflammatory cytokine IL-10 peaked at the end of CPB. The SOFA score increased from 1 (1, 2) preoperatively to 7 (5, 10) at 24 h after surgery, with a ΔSOFA of 6 (4, 8). Within 30 days after surgery, 48 patients (40.0%) developed AKI, 17 (14.2%) developed infection, 4 (3.3%) developed severe liver injury, 3 (2.5%) developed respiratory failure, and 3 (2.5%) experienced MACE. During the 2-year follow-up, 8 patients (6.7%) experienced MACE and 5 (4.2%) died. Conclusion: Multi-organ dysfunction is common after cardiac surgery under CPB (median ΔSOFA, 6), accompanied by perioperative activation of multiple immune-cell subsets and upregulation of pro-inflammatory, anti-inflammatory, and chemotactic mediators. This study provides data-driven evidence and research clues for further investigation of the associations between CPB-related immune perturbations and postoperative organ dysfunction and clinical outcomes.

Objective To investigate the relationship of neutrophil to lymphocyte ratio (NLR) and homocysteine (Hcy) with risk of coronary artery lesion progression in patients with hypertension. Methods The data of 306 patients with hypertension who received coronary angiography from January 2020 to January 2025 were included for retrospective investigation. The patients were divided into a non-progression group (175 cases) and a progression group (131 cases) based on the 6-month Gensini progression rate. The relationship between NLR and Hcy and coronary artery lesion progression was analyzed. Results Binary logistic regression analysis was applied to control confounding factors. After adjusting for confounding factors using Model1, Model2, and Model3, it was found that NLR and Hcy at admission were independently associated with the progression of coronary artery lesion in hypertensive patients [adjusted OR (95% CI) = 1.77 (1.48-2.11), 4.26 (2.71-6.69), P<0.001]. Receiver operating characteristic (ROC) curve revealed that the area under the curve of the combination of Hcy and NLR was 0.814 in predicting the progression of coronary artery lesion in hypertensive patients, which was higher than that of Hcy or NLR (Z/P=5.328, 2.077/<0.05). Conclusion Cardiovascular disease risk factors NLR and Hcy are independently associated with coronary artery lesion progression in patients with hypertension. Early detection of NLR and Hcy is helpful to predict the progression of coronary artery lesion.