Etiología y evolución de la anemia en pacientes sometidos a cirugía cardiovascular / Etiology and evolution of anemia in patients submitted to cardiovascular surgery

Resumen Objetivo: El objetivo del presente estudio es evaluar en nuestro medio la prevalencia de anemia en el preoperatorio de la cirugía cardiovascular, su incidencia postoperatoria y su evolución durante el primer mes. Métodos: Se realizó un estudio de cohorte prospectivo en el que se incluyeron todos los pacientes sometidos a cirugía cardiovascular central intervenidos durante el periodo del 01/09/2021 al 01/09/2022 en un hospital universitario. Se realizó seguimiento clínico y de laboratorio previo a la cirugía, al quinto y al día treinta del postoperatorio. Se comparó a los grupos con y sin anemia preoperatoria. Resultados: La prevalencia de anemia en el preoperatorio fue del 32.1%. La incidencia de anemia en el postoperatorio fue del 96% en el grupo de pacientes sin anemia previa. Al mes de la cirugía un 73 y un 90% de los pacientes, con y sin anemia preoperatoria respectivamente, persistían anémicos. Los pacientes con anemia preoperatoria tuvieron una menor recuperación de sus valores de hemoglobina al mes. Se observó una tendencia a mayor mortalidad y una mayor necesidad de derivación a centros de rehabilitación postegreso hospitalario en aquellos con anemia preoperatoria. Conclusiones: En este trabajo se evidenció una alta prevalencia e incidencia de anemia en el perioperatorio de las cirugías cardiovasculares. Así como su subtratamiento y elevada persistencia durante el mes posterior a la cirugía.

Abstract Objective: The aim of this study is to evaluate the prevalence of anemia in the preoperative period of cardiovascular surgery, its postoperative incidence and its evolution during the first month in our setting. Methods: A prospective cohort study was carried out in which all patients undergoing central cardiovascular surgery operated during the period 09/01/2021-09/01/2022 in a university hospital were included. Clinical and laboratory follow-up was carried out prior to surgery, on the fifth and on the 30th postoperative day. Groups with and without preoperative anemia were compared. Results: The prevalence of anemia in the preoperative period was 32.1%. The incidence of anemia in the postoperative period was 96% in the group of patients without previous anemia. One month after surgery, 73 and 90% of the patients, with and without preoperative anemia, respectively, remained anemic. Patients with preoperative anemia had less recovery of their hemoglobin values at one month. A trend towards higher mortality and a greater need for referral to post-hospital discharge rehabilitation centers was observed in those with preoperative anemia. Conclusions: In this work, a high prevalence and incidence of anemia in the perioperative period of cardiovascular surgeries was evidenced. As well as its subtreatment and high persistence during the month after surgery.

Hepcidin and inflammation associated with iron deficiency in childhood obesity - A systematic review

Abstract Objectives: This paper aims to review data on the association of obesity and iron deficiency in children and adolescents, exposing the possible involvement of hepcidin and interleukin-6 (IL-6), obesity's inflammation biomarkers. Data source: Articles from PUBMED and WEB OF SCIENCE database with no chronological limit were reviewed to write this systematic review. Keywords such as children, obesity, iron deficiency, and hepcidin were used. After deleting duplicated and review articles, 91 were screened, and 39 were selected as eligible. Sixteen articles were included because they involved serum hepcidin levels in obese children and adolescents as outcomes. Summary of findings: Finally, those 16 articles were organized in two tables: one includes therapeutic interventions, and the other does not. As hepcidin was discovered in 2000, the first articles that presented serum hepcidin's quantification in obese children and adolescents, homeostasis iron markers, and their possible association with obesity's inflammatory environment began to be published in 2008. Conclusions: Obesity's chronic inflammation state leads to the production of IL-6, which acts as a signaling molecule for hepcidin synthesis, resulting in iron deficiency, which is common in obese children and adolescents who respond inadequately to iron supplementation. On the other hand, that population responds adequately to therapeutic intervention programs that lead to weight loss, guaranteeing iron homeostasis improvement. Therefore, perhaps it is time to discuss serum hepcidin level quantification as part of evaluating children and adolescents with iron deficiency, which could guide clinical choices that might lead to better therapeutic outcomes.

Factores asociados a anemia ferropénica en lactantes y preescolares / Factors associated with iron deficiency anemia in infants and preschoolers

Introducción: La anemia se define como una afección en la cual el número de glóbulos rojos o la concentración de hemoglobina dentro de estos se encuentran por debajo del límite inferior, 11 gr/dl para menores entre 6 a 59 meses. La OMS calcula que a nivel mundial la anemia presenta una prevalencia del 42% en los niños menores de 5 años. Objetivos: Realizar una revisión panorámica de diversas publicaciones científicas acerca de los factores asociados a la anemia ferropénica en preescolares. Materiales y métodos: La revisión se realizó a través de la búsqueda electrónica de diversos artículos científicos relacionados con el tema. Se utilizó la pregunta PEO: ¿Cuáles son los factores asociados a anemia ferropénica en lactantes y preescolares? Se seleccionaron los artículos publicados desde el 2017 hasta el 2022. Resultados: De los 48 artículos encontrados en la revisión, 33 fueron descartados por no cumplir con nuestros criterios de selección, quedando 15 artículos para esta revisión. Basado en 12 artículos revisados, se halló que los factores que se asocian a anemia en menores de 5 años eran por problemas socioeconómicos, déficit de micronutrientes altos en hierro en dieta, madre con antecedente de anemia, la edad materna, falta de educación, entre otros. Conclusión: Los factores predisponentes para la presencia de anemia ferropénica en los menores de 5 años más importantes fueron los relacionados con la edad materna, el nivel socioeconómico y educativo de la madre que conllevan el déficit de hierro del menor.

Introduction: Anemia is defined as a condition in which the number of red blood cells or the hemoglobin concentration within red blood cells is below the lower limit, 11 g/dL for children aged 6-59 months. The WHO estimates that worldwide anemia has a prevalence of 42% in children under 5 years of age. Objectives: To perform an overview review of various scientific publications on the factors associated with iron deficiency anemia in preschoolers. Materials and methods: The review was carried out through an electronic search of various scientific articles related to the subject. The PEO question was used: What are the factors associated with iron deficiency anemia in infants and preschoolers? Articles published from 2017 to 2022 were selected. Results: Of the 48 articles found in the review, 33 were discarded for not meeting our selection criteria, leaving 15 articles for this review. Based on 12 articles reviewed, it was found that the factors associated with anemia in children under 5 years of age were socioeconomic problems, deficiency of micronutrients high in iron in the diet, mothers with a history of anemia, maternal age, lack of education, among others. Conclusion: The most important predisposing factors for the presence of iron deficiency anemia in children under 5 years of age were those related to maternal age, socioeconomic and educational level of the mother that lead to iron deficiency in the child.

Riesgos y beneficios de la profilaxis con sulfato ferroso en lactantes nacidos a término con niveles de hemoglobina y ferremia desconocidos / Risks and benefits of iron supplementation in full-term infants with unknown hemoglobin and ferritin levels

La seguridad y eficacia de los programas de suplementación con hierro a lactantes, está actualmente en discusión. El objetivo de esta revisión fue identificar estudios sobre riesgos y beneficios de la suplementación con hierro profiláctico en lactantes menores de un año, nacidos a término, con niveles de hemoglobina (Hb) y ferremia desconocidos. Se realizó una búsqueda en Pubmed y Cochrane, identificando 3 revisiones sistemáticas y metaanálisis. Estos estudios arrojaron resultados que indican mejoras en los niveles séricos de hierro y hemoglobina como resultado de la suplementación con hierro. Sin embargo, no se observó un beneficio significativo en el desarrollo cognitivo de los lactantes. Los efectos adversos más reportados son los gastrointestinales, efectos en el crecimiento (menor ganancia de talla y peso) y menor absorción de zinc. En resumen, la evidencia en cuanto a la profilaxis con hierro en lactantes es limitada, lo que nos lleva a recomendar un seguimiento cercano de los lactantes que reciben suplementos de hierro, con el objetivo de detectar posibles eventos adversos. Es fundamental evaluar cuidadosamente los riesgos y beneficios de esta intervención antes de su implementación (AU)

The safety and efficacy of iron supplementation programs for infants are currently under discussion. The objective of this review was to identify studies on the risks and benefits of prophylactic iron supplementation in infants under one year of age, born at term, with unknown hemoglobin (Hb) and serum iron levels. The search was conducted on Pubmed and Cochrane, identifying three systematic reviews and meta-analyses. The results indicate improvements in serum iron and hemoglobin levels as a result of iron supplementation. However, a significant benefit in infant cognitive development was not observed. The most reported adverse effects were gastrointestinal, effects on growth (reduced height and weight gain), and reduced zinc absorption. In summary, the evidence regarding iron prophylaxis in infants is limited, leading us to recommend close monitoring of infants receiving iron supplements to detect potential adverse events. It is crucial to carefully assess the risks and benefits of this intervention before implementation (AU)

Características de los niños hospitalizados que recibieron transfusiones de sangre desplasmatizada durante el 2019: Hospital Pediátrico-Centro Hospitalario Pereira Rossell / Characteristics of hospitalized children who received deplasmatized blood transfusions during 2019: Hospital Pediátrico-Centro Hospitalario Pereira Rossell / Características das crianças hospitalizadas que receberam transfusões de sangue desplasmatizado durante 2019: Hospital Pediátrico-Centro Hospitalario Pereira Rossell

Introducción: la terapia transfusional es un procedimiento terapéutico que ha contribuido a disminuir la mortalidad, y mejorar la calidad de vida de pacientes con diversas patologías. La utilización de guías en la práctica transfusional, contribuye a la utilización racional de las mismas. Objetivo: describir las características de los niños de 1 mes a 14 años 11 meses hospitalizados en el Centro Hospitalario Pereira Rossell durante el 2019 que recibieron transfusión de sangre desplasmatizada. Metodología: estudio descriptivo retrospectivo. Se incluyeron los niños entre 1 mes y 14 años 11 meses asistidos en emergencia, unidad de reanimación, cuidados moderados, intermedios e intensivos del Centro Hospitalario Pereira Rossell. Variables: edad, sexo, área de asistencia, motivo de ingreso, indicación de transfusión, cifras de Hb pre y post-transfusión, clasificación de la anemia, dosis. Resultados: se incluyeron 160 transfusiones correspondientes a 97 pacientes, 56% eran de sexo masculino. Media de edad 3 años, 52% < 1 año. El motivo de ingreso más frecuente fue patología respiratoria infecciosa 37%. El 79% fueron transfundidos en unidad de cuidados intermedios e intensivos. Media Hb pre-transfusión 7,45 g/dL y post-transfusión de 10,1 g/dL. Predominó la anemia moderada, normocítica-normocrómica, pura. La dosis media de sangre desplasmatizada transfundida fue 12 cc/kg. Conclusiones: en esta serie predominaron los pacientes de sexo masculino y menores a un año que ingresaron principalmente por patología respiratoria infecciosa. La mayoría de los pacientes transfundidos estaban en cuidados intensivos. Futuros estudios, de diseño prospectivo, que incluyan pacientes de todos los escenarios asistenciales y de otros prestadores de salud, contribuirán a continuar el estudio de los pacientes transfundidos y a la elaboración de recomendaciones o protocolos locales.

Introduction: Transfusion therapy is a therapeutic procedure that has contributed to reducing mortality and improving the quality of life of patients with various pathologies. The use of guides in transfusion practice contributes to their rational use. Objective: To describe the characteristics of children from 1 month to 14 years 11 months who were hospitalized in the Centro Hospitalario Pereira Rossell during 2019 who received a red blood cell transfusion. Methodology: Retrospective descriptive study. Children aged 1 month to 14 years and 11 months assisted in the emergency, moderate, intermediate and intensive care of the Centro Hospitalario Pereira Rossell were included in the study. Variables: age, sex, area of care, reason for admission, indication for transfusion, Hb figures before and after transfusion, classification of anaemia, dose. The study protocol was approved by the Institutional Ethics Committee. Results:160 transfusions corresponding to 97 patients were included, 56% were male. Mean age 3 years, 52% <1 year. The most frequent reason for admission was infectious respiratory disease 37%. 79% were transfused in the intermediate and intensive care unit. Mean Hb pre-transfusion 7.45 g/dL and post- transfusion of 10.1 g/dL. Moderate, normocytic-normochromic, pure anaemia predominated. The mean dose of deplasmatized blood transfused was 12 cc/kg. Conclusions: In this series, male patients less than one year of age predominated, admitted mainly for infectious respiratory disease. Most of the transfused patients were in intensive care. Future studies of prospective design that include patients from all healthcare settings and from other healthcare providers, will contribute to continuing the study of transfused patients and to the development of local recommendations or protocols.

Introdução: a terapia transfusional é um procedimento terapêutico que tem contribuído para reduzir a mortalidade e melhorar a qualidade de vida de pacientes com diversas patologias. A utilização de diretrizes na prática transfusional contribui para o seu uso racional. Objetivo: descrever as características das crianças de 1 mês a 14 anos e 11 meses internadas no Centro Hospitalario Pereira Rossell durante o ano de 2019 que receberam transfusão de sangue desplasmatizado. Metodologia: estudo descritivo retrospectivo. Foram incluídas crianças com idade entre 1 mês e 14 anos e 11 meses atendidas na emergência, unidade de reanimação, cuidados moderados, intermediários e intensivos do Centro Hospitalario Pereira Rossell. Variáveis: idade, sexo, área de atendimento, motivo da admissão, indicação de transfusão, valores de Hb pré e pós-transfusão, classificação da anemia, dose. Resultados: foram incluídas 160 transfusões correspondentes a 97 pacientes, 56% eram do sexo masculino. A idade média foi de 3 anos, 52% < 1 ano. O motivo mais frequente de admissão foi pato- logia respiratória infecciosa (37%). 79% foram transfundidos na unidade de tratamento intermediário e intensivo. Hb média pré-transfusional de 7,45 g/dL e Hb pós-transfusional de 10,1 g/dL. Predominou a anemia moderada, normocítica-normocrômica e pura. A dose média de sangue desplasmatizado transfundida foi de 12 cc/kg. Conclusões: nesta série, houve uma predominância de pacientes do sexo masculino com menos de um ano de idade que foram admitidos principalmente por patologia respiratória infecciosa. A maioria dos pacientes transfundidos estava em tratamento intensivo. Estudos prospectivos futuros incluindo pacientes de todos os ambientes de atendimento e outros presta- dores de serviços de saúde, contribuirão para um estudo mais aprofundado dos pacientes transfundidos e para o desenvolvimento de recomendações ou protocolos locais.

Is Iron Overload Associated with Worse Outcomes in Patients with Chronic Liver Disease Undergoing Liver Transplantation?

ABSTRACT Background: Iron overload is frequent in patients with chronic liver disease, associated with shorter survival after liver transplantation in patients with hereditary hemochromatosis. Its effect on patients without hereditary hemochromatosis is unclear. The aim of the study was to study the clinical impact of iron overload in patients who underwent liver transplantation at an academic tertiary referral center. Methods: We performed a retrospective cohort study including all patients without hereditary hemochromatosis who underwent liver transplantation from 2015 to 2017 at an academic tertiary referral center in Mexico City. Explant liver biopsies were reprocessed to obtain the histochemical hepatic iron index, considering a score ≥ 0.15 as iron overload. Baseline characteristics were compared between patients with and without iron overload. Survival was estimated using the Kaplan-Meier method, compared with the log-rank test and the Cox proportional hazards model. Results: Of 105 patients included, 45% had iron overload. Viral and metabolic etiologies, alcohol consumption, and obesity were more frequent in patients with iron overload than in those without iron overload (43% vs. 21%, 32% vs. 22%, p = 0.011; 34% vs. 9%, p = 0.001; and 32% vs. 12%, p = 0.013, respectively). Eight patients died within 90 days after liver transplantation (one with iron overload). Complication rate was higher in patients with iron overload versus those without iron overload (223 vs. 93 events/100 person-months; median time to any complication of 2 vs. 3 days, p = 0.043), without differences in complication type. Fatality rate was lower in patients with iron overload versus those without iron overload (0.7 vs. 4.5 deaths/100 person-months, p = 0.055). Conclusion: Detecting iron overload might identify patients at risk of early complications after liver transplantation. Further studies are required to understand the role of iron overload in survival.

Research progress on the role of ferroptosis in the pathogenesis of non-alcoholic fatty liver disease / 基础医学与临床

Ferroptosis is a new type of cell death proposed in recent years,and its main characteristics are iron overload and lipid peroxidation.Ferroptosis is involved in the occurrence and development of non-alcoholic fatty liv-er disease(NAFLD).Iron overload can generate a large amount of reactive oxygen species through the Fenton reac-tion.Under the action of lipoxygenase,the unsaturated fatty acids on the liver cell membrane undergo lipid peroxi-dation,which induces liver cell death and leads to the occurrence of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis.Blocking ferroptosis may provide one of the therapeutic strategies to protect liver cells.

Research Progress of Iron Death in Cardiomyopathy / 昆明医科大学学报

Cardiomyopathy is a group of heterogeneous myocardial diseases with a variety of specific phenotypes that can lead to cardiovascular death or progressive heart failure in severe cases.Because of the severity and complexity of these diseases,the search for new regulatory mechanisms to prevent and treat cardiomyopathy is particularly urgent.Iron death is a form of programmed cell death that differs from other forms of iron dependence and is characterized by the accumulation of iron-dependent lipid peroxides.Studies have shown that iron death can be involved in the occurrence and progression of cardiomyopathy through different signaling pathways.Therefore,targeted regulation of iron death is a new strategy to prevent cardiomyopathy.In this paper,the mechanism of iron death and its important role in cardiomyopathy were reviewed to find the potential relationship between iron death and cardiomyopathy and provide more ideas for the treatment of various cardiomyopathies in the future.

Research progress in ceruloplasmin regulation of lipid metabolism homeostasis / 上海交通大学学报（医学版）

Ceruloplasmin(Cp)is a crucial protein secreted by the liver and plays a vital role in regulating the distribution and transport of copper throughout the body,thereby maintaining copper homeostasis.Additionally,Cp functions as a significant enzyme known as ferroxidase,which is involved in iron metabolism within the body.Numerous studies have suggested a close relationship between Cp and metabolic disorders,such as diabetes and cardiovascular diseases.Recent research has also shed light on the involvement of Cp in the regulation of lipid metabolism.The various activities associated with lipid metabolism,including lipid synthesis,adipose hydrolysis,fatty acid oxidation,lipid transport,and absorption,collectively contribute to maintaining lipid homeostasis.Dysregulation of lipid metabolism can lead to metabolic disorders and cardiovascular complications.Cp regulates lipid metabolism through two main mechanisms.Firstly,Cp participates in the regulation of oxidative stress by modulating iron metabolism through its ferroxidase activity and involvement in redox reaction.Secondly,copper along with copper-dependent enzymes directly participates in the processes such as cholesterol metabolism,lipoprotein metabolism,and fatty acid synthesis.As a result,the role of Cp in maintaining the homeostasis of copper and iron allows it to regulate lipid metabolism by influencing copper or iron-dependent enzymes and related pathways.Although the correlation between Cp and lipid metabolism has been identified,an in-depth exploration of the precise mechanisms by which Cp governs lipid metabolism is warranted.This article provides an overview of the role of Cp in lipid metabolism and highlights the progress in related research,with the aim of providing new insights for the development and treatment of disorders related to lipid metabolism.

Quantitative evaluation of gender differences in supraclavicular fat related to fat metabolism with IDEAL-IQ in healthy young adults / 实用放射学杂志

Objective To evaluate the gender differences in fat water fraction(FWF)related to fat metabolism in supraclavicular region of neck with iterative decomposition of water and fat with echo asymmetry and least square estimation iron quantification(IDEAL-IQ)sequence quantitatively.Methods Twenty healthy female and twenty healthy male volunteers were selected for a MRI examination with IDEAL-IQ,then the FWF of R2*,brown adipose tissue(BAT)and white adipose tissue(WAT)were obtained by post-processing.The differences of FWF between the two groups were compared by Mann-Whitney U test.Results There was sig-nificant difference in the FWF of BAT and WAT between the two groups(P＜0.05).The FWF of BAT in the female was higher than that the male,and the FWF of WAT in the male was higher than that the female,there was no significant difference in the R2*between the two groups(P＞0.05).Conclusion IDEAL-IQ sequence can be used to evaluate the FWF in supraclavicular region of neck quantitatively,and classify BAT and WAT,then provide clinical according to the quantitative study of fat content.

Mechanism of iron death induced by high homocysteine via TRPC6/NF-κb in glomerular podiatocytes / 实用医学杂志

Objective To investigate the mechanism of iron death induced by TRPC6/NF-κB in glomerular podiocytes mediated by high homocysteine(Hcy).Methods Mouse glomerulopocytes were cultured in vitro and divided into Control group(0 μmol/L Hcy)and Hcy group(80 μmol/L Hcy).After 48h of intervention,Western blot was used to detect the expression levels of iron death related proteins GPX4 and SLC7A11 and TRPC6 and NF-κ B.Real-time quantitative fluorescence PCR(qRT-PCR)and immunofluorescence were used to detect the expression of TRPC6.The level of podocyte apoptosis was detected by flow cytometry.Malondialdehyde(MDA)assay kit was used to determine intracellular MDA levels.After transfection of TRPC6 interference fragment and TRPC6 negative control(NC),qRT-PCR was divided into Control,si-NC and si-TRPC6(Si-TRPC6-1,Si-TRPC6-2,Si-TRPC6-3).Western Blot was divided into Control,Hcy,si-NC+Hcy,si-TRPC6+Hcy.The expression of TRPC6 mRNA was detected by qRT-PCR.The expression levels of GPX4,SLC7A11,NF-κB and TRPC6 were detected by Western Blot.The level of podocyte apoptosis after interference was detected by flow cytometry.Results(1)Compared with Control group,the expression levels of iron death related proteins GPX4 and SLC7A11 in Hcy group were decreased,and the apoptosis rate was increased(P<0.05).(2)Compared with Control group,TRPC6 protein,mRNA levels and immunofluorescence expression were increased in Hcy group.The level of MDA and the expression of NF-κB signaling pathway protein increased in Hcy group,and the comparison between the two groups had statistical significance(P<0.05).(3)Compared with the si-NC group,the mRNA expression level of TRPC6 in si-TRPC6(Si-TRPC6-1,Si-TRPC6-2,Si-TRPC6-3)group was decreased,and the interference effect of Si-TRPC6-3 was the best(P<0.05).After transfecting TRPC6 NC and TRPC6 interference fragment and administering Hcy,there was no difference in GPX4,SLC7A11,NF-κB and TRPC6 expression in si-NC+Hcy group compared with Hcy group.Compared with the si-NC+Hcy group,the si-TRPC6+Hcy group had higher expression of iron death related proteins,GPX4 and SLC7A11,lower expression of NF-κB and TRPC6,and decreased apoptosis rate(P<0.05).Conclusion This study confirmed that TRPC6/NF-κB can regulate iron death of renal podocytes under the induc-tion of Hcy,which is one of the mechanisms leading to kidney injury.

Iron overload regulates atherosclerotic activity of foam cells induced by oxLDL / 实用医学杂志

Objective To explore the roles of iron overload in pro-atherogenic activation of foam cells.Methods RAW264.7 and MOVAS cells were stimulated by oxLDL,ferrimine citrate and deferoxamine respectively.Prussian Blue and Oil Red O staining were used to detect iron deposition and foam cell.CCK-8 test,DHE probe,ELISA,RT-qPCR were performed to detect the cell death rate,reactive oxygen species(ROS)generation,lipid peroxidation molecules[glutathione peroxidase(GSH),glutathione peroxidase 4(GPX4),malondialdehyde(MDA)content]and the mRNA level of ATP binding cassette transporter A1(ABCA1),ATP binding cassette transporter G1(ABCG1),inductible nitris oxide synthase(iNOS),arginase-1(Arg-1),α-smooth muscle actin(α-SMA),smooth muscle 22 alpha(SM22a),osteopontin(OPN),Interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α).Results Iron overload could reduced reverse cholesterol transporters(ABCA1 and ABCG1),promote foam cells generation,increased cell death rate,induced the expression of lipid peroxidation molecules(GSH,GPX4,MDA),and promoted pro-inflammatory M1 marker of macrophage and synthetic marker expression of vascular smooth muscle cell(VSMC)and inflammatory cytokines(IL-1β,TNF-α).Conclusion Iron overload promotes the generation of foam cells derived from macrophages and smooth muscle cells and transform them into pro-atherosclerotic phenotype,aggravates cell lipid peroxidation and inflammatory reaction,which contributes to the progress of atherosclerosis.

Function and advantages of magnetically responsive hydrogel in bone tissue engineering / 中国组织工程研究

BACKGROUND:Magnetically responsive hydrogels have great advantages in bone tissue engineering,which is more conducive to the minimally invasive and efficient promotion of osteogenesis. OBJECTIVE:To review the application advances of magnetically responsive hydrogels in bone tissue engineering. METHODS:PubMed,Web of Science,WanFang and CNKI databases were used to search relevant literature.The English search terms were"Magnetic Hydrogels,Magnetic Nanoparticles,Superparamagnetic Nanoparticles,Fe3O4,SPIONs,Magnetic Fields,Bone Regeneration,Bone Repair,Bone Tissue Engineering".The Chinese search terms were"Magnetic Hydrogel,Magnetic Nanoparticles,Superparamagnetic Iron Oxide Nanoparticles,Magnetic Field,Iron Oxide Nanoparticles,Bone Regeneration,Bone Reconstruction,Bone Repair,Bone Tissue Engineering".After preliminary screening of all articles according to the inclusion and exclusion criteria,60 articles were finally retained for review. RESULTS AND CONCLUSION:(1)In recent years,due to the emergence of magnetic nanoparticles,more and more magnetic responsive scaffold materials have been developed.Among them,magnetic responsive hydrogels containing iron oxide nanoparticles and superparamagnetic iron oxide nanoparticles have outstanding mechanical properties and good biocompatibility.It can quickly respond to the external magnetic field and provide the magnetic-mechanical signals needed for seed cells to form bone.(2)Magnetic-responsive hydrogel can be used as a carrier to accurately regulate the release time of growth factors.(3)Under the three-dimensional microenvironment culture platform based on magnetically responsive hydrogel,the magnetic force at the interface between the magnetic response hydrogel and cells can activate cell surface sensitive receptors,enhance cell activity,and promote the integration of new bone and host bone.(4)The injectable magnetically responsive hydrogel can be used in the field of magnetic hyperthermia and biological imaging of bone tumors.(5)At present,magnetically responsive hydrogels are expected to mimic the anisotropic layered structure observed in natural bone tissue.However,most of the studies on magnetically responsive hydrogels focus on in vitro studies,and the mechanism of interaction between magnetically responsive hydrogels and the local microenvironment in vivo is still insufficient.(6)Therefore,based on the successful application of magnetic nanoparticles in magnetic resonance imaging,it is expected to optimize the properties of magnetic nanoparticles in the future to construct magnetic responsive hydrogels with suitable degradation properties,mechanical properties,and vascular functionalization,which can monitor changes in vivo in real time.

An insight into the mechanism of iron overload in knee osteoarthritis under the theory of blood stasis / 中国组织工程研究

BACKGROUND:Knee osteoarthritis is a common disease in middle-aged and elderly people.It is a kind of disease that seriously affects the quality of life of patients and even has the risk of disability.Therefore,the pathogenesis and treatment of knee osteoarthritis have become the focus of research.In Chinese medicine,knee osteoarthritis is often treated as"biness,"which is closely related to"biness"caused by blood stasis and blood vessels blocking collaterals in the theory of"blood stasis"in traditional Chinese medicine.Iron overload is a kind of pathological state caused by iron metabolism disorder,which highly coincides with the pathogenic characteristics and clinical manifestations of the"blood stasis"theory of traditional Chinese medicine,and is a risk factor that promotes the development of knee osteoarthritis. OBJECTIVE:Based on the"blood stasis"theory,to summarize the effects of iron overload on cartilage metabolism and subchondral bone reconstruction,to lay a new theoretical foundation for the treatment of knee osteoarthritis with traditional Chinese medicine,and to explore the therapeutic effect of traditional Chinese medicine for promoting blood circulation after interfering with bone tissue. METHODS:CNKI,WanFang database,PubMed and Web of Science databases were searched for relevant literature.The Chinese search terms were"ferroptosis,iron,iron overload,osteoarthritis,blood stasis"and the English search terms were"ferroptosis,iron,iron overload,osteoarthritis,TCM."In the end,76 articles were included for further review. RESULTS AND CONCLUSION:First of all,we explored the potential of the"blood stasis"theory in treating knee osteoarthritis,and found that"blood stasis"is a crucial part in the progress of knee osteoarthritis,indicating that the"blood stasis"theory is the key to the treatment of knee osteoarthritis in traditional Chinese medicine.Secondly,"blood stasis"and iron overload have a high degree of similarity in pathogenic factors,clinical manifestations,and pathogenic characteristics,suggesting the possibility of"blood stasis"theory in treating iron overload.This finding reminds us that iron overload may be an important mechanistic basis for the"blood stasis"theory in the treatment of knee osteoarthritis.The extracts of blood-activating drugs can relieve iron overload and treat knee osteoarthritis,but the specific mechanism is still unclear.Therefore,we believe that the relationship between"blood stasis"theory and iron overload and related mechanisms are important research directions for knee osteoarthritis in the future.The related mechanism of"blood stasis"theory to alleviate iron overload and then treat knee osteoarthritis also provides a theoretical basis for the modernization of traditional Chinese medicine,such as the development of new drugs and innovative usage,and has certain guiding significance for clinical practice.

Ferroptosis in bone diseases:therapeutic targets of osteoporosis / 中国组织工程研究

BACKGROUND:With the aging of the global population,the incidence rate of osteoporosis is also increasing.It is very important to further understand its pathogenesis and propose new therapeutic targets.Recent studies have shown that ferroptosis is closely related to the pathogenesis of some bone diseases,such as inflammatory arthritis,osteoporosis and osteoarthritis. OBJECTIVE:To summarize the previous studies on the mechanism of ferroptosis in osteoporosis,so as to provide new therapeutic ideas and potential therapeutic targets for osteoporosis. METHODS:The first author used the computer to search the documents published from 2000 to 2022 in CNKI,WanFang,VIP,PubMed and Web of Science with the key words of"ferroptosis,osteoporosis,osteoblasts,osteoclasts,iron chelators,reactive oxygen species,nuclear factor erythroid 2-related factor 2,heme oxygenase-1,glutathione peroxidase 4,review"in Chinese and English.A total of 70 articles were finally included according to the inclusion criteria. RESULTS AND CONCLUSION:Ferroptosis is significantly different from necrosis,apoptosis and autophagy.In terms of cell morphology and function,it does not have the morphological characteristics of typical necrosis,nor does it have the characteristics of traditional apoptosis,such as cell contraction,chromatin condensation,the formation of apoptotic bodies and the disintegration of cytoskeleton.Contrary to autophagy,ferroptosis does not form a classical closed bilayer membrane structure(autophagic vacuole).Morphologically,ferroptosis is mainly manifested by obvious contraction of mitochondria,increased membrane density,and reduction or disappearance of mitochondrial cristae,which are different from other cell death modes.Iron overload can destroy bone homeostasis by significantly inhibiting osteogenic differentiation and stimulating osteoclast formation,leading to osteoporosis.Iron overload interferes with the differentiation of stem cells to osteoblasts,leading to a weakened osteoblast function and further imbalance of bone metabolism in the body,which eventually leads to osteoporosis.Stimulated by iron overload,osteoclast bone resorption is enhanced and bone loss exceeds new bone formation.Iron chelators have been proved to have osteoprotective effects by inhibiting osteoclast activity and stimulating osteogenic differentiation of osteoblasts.Its potential mechanism is related to inhibiting osteoclast differentiation and promoting osteoblast differentiation.Antioxidants can prevent reactive oxygen species production and inhibit bone absorption,thus improving bone metabolism and effectively preventing osteoporosis.

Deferoxamine mesylate improves the repair of jaw bone defects in an ovariectomized rat model of osteoporosis / 中国组织工程研究

BACKGROUND:Deferoxamine mesylate is a potential anti-osteoporosis drug with iron chelation,vascular regeneration,and antioxidant effects.Recent studies have shown that the application of deferoxamine mesylate can be extended to the field of tissue regeneration engineering. OBJECTIVE:To investigate whether deferoxamine mesylate can promote the repair effect of iron overload osteoporotic rats after bone grafting for mandibular bone defects by simulating the state of iron accumulation in patients with postmenopausal osteoporosis with high iron intervention in osteoporotic rats. METHODS:An iron accumulation ovariectomized osteoporosis model was firstly constructed.The model group underwent bilateral ovariectomy,and the intraperitoneal injection of ferric ammonium citrate(90 mg/kg,twice a week,for 11 weeks)was started in the 2nd week,while the sham-operated group had some fat around the ovaries removed and was given an equal amount of saline for 11 weeks.After the successful modeling,the experimental rats were divided into sham-operated group(n=6),high iron ovariectomtized group(n=6)and high iron ovariectomized deferoxamine mesylate treatment group(deferoxamine mesylate group,n=6).Bone defects of 5 mm in diameter were established in the rat's bilateral mandibles and implanted with Bio-Oss bone powder.Intraperitoneal injection of deferoxamine mesylate(100 mg/kg,3 times a week)was started on postoperative day 4 in the deferoxamine mesylate group,and equal volume of saline was given in the sham-operated and high iron ovariectomized groups.The bone samples of the mandible,liver and blood were taken at 2 and 12 weeks after bone grafting for Prussian blue staining of the jaw and liver and ELISA detection of serum ferritin to detect iron levels in various body tissues;hematoxylin-eosin staining and Masson staining were performed to observe inflammatory cell infiltration and early osteogenesis in the bone defect area;tartrate resistant acid phosphatase staining was performed to observe osteoclast differentiation;ELISA was performed to detect serum calcitonin and type I collagen C-terminal peptide levels;and Micro-CT and hematoxylin-eosin staining were performed to observe osteogenesis in the middle and late stages. RESULTS AND CONCLUSION:The number of tibial trabeculae was reduced and the trabeculae were sparsely arranged in the high iron ovariectomized group.Iron levels in the liver,jaw bone and serum were significantly higher in the high iron ovariectomized group than the sham-operated group at 2 weeks after bone grafting,while the iron levels were significantly decreased after deferoxamine mesylate intervention(P＜0.05).In the early stage of bone defect repair,more inflammatory cell infiltration,less new bone matrix and less type I collagen fiber production were observed in the high iron ovariectomized group than in the sham-operated group(P＜0.05);after deferoxamine mesylate treatment,inflammatory cell infiltration was reduced,a small amount of new bone matrix was produced and collagen fibers increased significantly(P＜0.05).In the middle and late stages of bone defect repair,Micro-CT results showed a reduction in new bone production in the high iron ovariectomized group compared with the sham-operated group and increased new bone matrix after deferoxamine mesylate treatment(P＜0.05).Compared with the sham-operated group,the osteoclast number,serum calcitonin level,and serum type I collagen C-terminal peptide level were increased in the high-iron ovariectomized group,while the osteoclast number was decreased and bone metabolic indexes were improved after treatment with deferoxamine mesylate.To conclude,in ovariectomized rats with high iron intervention,elevated iron levels can be seen in multiple tissues,accompanied by reduced new bone production in the mandibular bone defect area.Deferoxamine mesylate can improve bone metabolism and inhibit osteoclast activity by removing iron deposits in tissues,improve bone formation in iron-accumulated osteoporotic rats,and promote bone healing in the mandibular bone defect area.

Application of deferoxamine in bone tissue regeneration / 中国组织工程研究

BACKGROUND:Aside from iron chelating,deferoxamine is also considered as an effective hypoxia mimetic agent and hypoxia inducible factor-1α stabilizer.Deferoxamine has played a favorable effect on bone regeneration in both basic and clinical research recently.Deferoxamine solutions or deferoxamine loaded bio-scaffolds have been locally applied in bone tissue engineering,and their promotion of bone repair involves various functional properties and molecular mechanisms which have not been entirely clarified.Moreover,their advances in research of bone regeneration lack comprehensive summary as well. OBJECTIVE:To review the functional properties,relative merits and advances in basic research and clinical practice of deferoxamine applied in bone regeneration,attempting to provide references and strategies for further studies. METHODS:Relevant articles were searched with the key words of"deferoxamine OR desferrioxamine OR desferal OR DFO,""bone tissue engineering OR bone regeneration OR bone remodeling OR bone repair OR bone healing OR osteogenesis,""angiogenesis OR vascularized bone regeneration OR angiogenic-osteogenic coupling"in English and Chinese by using PubMed,WanFang and CNKI databases.Eventually,88 articles were selected for review. RESULTS AND CONCLUSION:Deferoxamine can recruit stem cells and regulate their function,activate relevant signaling pathways to advance hypoxia adaptation of the cells,exert anti-inflammatory and antioxidant properties to improve local inflammatory environment,and promote bone regeneration by coupling osteogenesis and angiogenesis as well as inhibiting bone resorption.Compared with growth factors or peptides loaded in conventional bone tissue engineering,deferoxamine has its unique advantages as a small molecule drug,while it also has toxic reactions and application limitations.Therefore,it is necessary to optimize its loading form and dosagey.The unique angiogenic-osteogenic coupling ability of deferoxamine can be used in different types of bone injuries including fractures,osteonecrosis,distraction osteogenesis,bone grafting,oral related osteogenesis,and bone defects.Due to the enhancement of angiogenesis,this ability enables deferoxamine to better adapt and solve the difficulties in bone repair caused by the complex and variable clinical situations and individual differences.However,it is also necessary to compare and optimize the application methods and safe dosage of deferoxamine to expand its application scope and enhance its clinical value.

Biological and physicochemical properties of bioactive ion modified brushite cements / 中国组织工程研究

BACKGROUND:As a bone replacement and filling material,calcium phosphate stone bone cement has good biocompatibility,bone conductivity,and other advantages,especially its better biodegradability compared to other calcium phosphate bone cements.It has important application value in bone repair.However,due to its limitations such as insufficient mechanical properties,fast solidification reaction,and poor injection performance,it is currently only suitable for the repair of non weight-bearing bone. OBJECTIVE:To explore the modification of brushite cements with bioactive ions(metal and non metal ions)to expand its application range. METHODS:The author used PubMed,ScienceDirect,CNKI,and WanFang to search the literature published between 2018 and 2023 with the search terms"metal ion,iron,copper,strontium,magnesium,zinc,non-metal ion,modification,bone,brushite cements"in Chinese and"metal ion,iron,Fe,copper,Cu,strontium,Sr,magnesium,Mg,zinc,Zn,non-metal ion,modification,bone,brushite cements"in English.After reading titles and abstracts,the articles were initially screened,and irrelevant and duplicate articles were excluded.Finally,64 articles were included for review. RESULTS AND CONCLUSION:(1)Bioactive ions affect the hydration process of calcium phosphate bone cement.Different ions are substituted by ions and incorporated into the crystal structure of calcium phosphate bone cement,changing the crystal morphology of the cement and causing changes in physical and chemical properties such as setting time,injectability,and compressive strength.(2)Ionic modified calcium phosphate bone cement produces different ion release effects due to different crystal structures.Different types of ions have properties such as promoting angiogenesis/osteogenesis,antibacterial,anti-tumor,etc.In addition,calcium phosphate bone cement has good biodegradability,which has great advantages for the performance of various ions.(3)The physicochemical properties of calcium phosphate bone cement modified with different ions are as follows:iron,copper,strontium,magnesium,zinc,silver,and cobalt can prolong the setting time.Strontium,and magnesium can improve injection performance.Copper,strontium,magnesium,silver and silicon can enhance compressive strength.The ions that can simultaneously improve the three physical and chemical properties of calcium phosphate bone cement include strontium and magnesium.Good physical and chemical properties are a prerequisite for clinical application,so improving the setting time,injectability,compressive strength,and other properties of calcium phosphate bone cement with ions is of great significance for the research and application of bone cement.(4)The biological properties of calcium phosphate bone cement modified with different ions are as follows:copper,strontium,magnesium,zinc,cobalt,lithium,selenium,and silicon have promoting angiogenesis/osteogenic effects.Iron,copper,magnesium,zinc,and silver have antibacterial properties.Magnesium ions have anti-inflammatory properties.Copper and selenium have anti-tumor properties.(5)In summary,magnesium ions can improve the setting time,injectability,and compressive strength of calcium phosphate bone cement,while also promoting neovascularization/osteogenesis,antibacterial properties,and have good application prospects for the treatment of bone defects with concurrent infections.In addition,copper also has anti-tumor properties,so copper ions have great potential in the treatment of bone defects caused by infections and tumors.However,relevant research is still in the basic research stage,and the effects of different ion doping concentrations and synthesis conditions on the physicochemical properties of calcium phosphate bone cement need to be further explored.At the same time,the impact of biological properties also needs to be studied and observed for a longer period of time.

Overexpression of SMAD4 interferes with the expression of iron metabolism related proteins in osteoporotic rats / 中国组织工程研究

BACKGROUND:SMAD family member 4(SMAD4)can promote bone remodeling in osteoporotic rats,but it is unclear whether SMAD4 interferes with the expression of iron metabolism related proteins in osteoporotic rats. OBJECTIVE:To explore the effect of SMAD4 overexpression on the expression of iron metabolism related proteins in osteoporotic rats. METHODS:Rats were randomized into sham group,ovariectomy group,transfection control group and SMAD4 overexpression group.Animal models of osteoporosis were established in the latter three groups by ovariectomy,and only adipose tissue was removed in the sham group.One week later,adenovirus was injected into the femoral bone marrow cavity.SMAD4 overexpression group and transfection control group were injected with adenovirus overexpressing SMAD4 gene and control empty virus,respectively.Index detection was performed at 1 month after injection.Micro-CT,hematoxylin-eosin staining and tartrate resistant acid phosphatase staining were used to detect bone formation and bone resorption in osteoporotic rats.ELISA was used to detect serum ferritin and hepcidin levels.Immunohistochemical staining was used to detect alkaline phosphatase,osteocalcin,receptor activator for nuclear factor-κB ligand and tartrate resistant acid phosphatase levels in femoral tissue.RT-qPCR was used to detect SMAD4,hepcidin,divalent metal transporter 1,transferrin receptor1 and ferroportin1 mRNA levels in femoral tissue.Western blot was used to detect SMAD4,alkaline phosphatase,osteocalcin,osteoprotegerin,receptor activator for nuclear factor-κB ligand,tartrate resistant acid phosphatase,β-Crosslaps,hepcidin,divalent metal transporter 1,transferrin receptor 1,and ferroportin 1 protein levels. RESULTS AND CONCLUSION:In the sham group,bone trabeculae in femur tissue were intact,and almost no osteoclasts were found.In the ovariectomy and transfection control groups,the bone trabeculae were sparse and a large number of osteoclasts were present.In the SMAD4 overexpression group,the number of bone trabeculae was increased and the number of osteoclasts was decreased.Compared with the sham group,the ovariectomy group showed a significant reduction in the protein expression of SMAD4,alkaline phosphatase,osteocalcin,and osteoprotegerin in femoral tissue and hepcidin levels in serum and femoral tissue,while receptor activator for nuclear factor-κB ligand,tartrate resistant acid phosphatase,β-Crosslaps protein levels,divalent metal transporter 1,transferrin receptor1,ferroportin1 mRNA and protein levels were significantly increased(P＜0.05).Compared with the transfection control group,the SMAD4 overexpression showed a significant increase in SMAD4,alkaline phosphatase,osteocalcin,and osteoprotegerin protein levels in femoral tissue and hepcidin levels in serum and femoral tissue,while the expressions of receptor activator for nuclear factor-κB ligand,tartrate resistant acid phosphatase,β-Crosslaps protein levels,divalent metal transporter 1,transferrin receptor1,and ferroportin 1 at mRNA and protein levels were significantly decreased(P＜0.05).To conclude,overexpression of SMAD4 promotes bone remodeling in osteoporotic rats by interfering with the expression of iron metabolism related proteins.

Progress in ferroptosis and its inhibitors in central nervous system diseases / 中国医科大学学报

The etiology of central nervous system(CNS)diseases is complex and mostly unknown,and patients are often left with sequelae and poor prognosis.Recently,ferroptosis has emerged as a unique oxidative stress-induced cell death pathway and is important in various CNS diseases.It is an important mode of neuronal cell death.This article summarizes the molecular mechanism of ferroptosis,research progress of ferroptosis in CNS diseases,and application of ferroptosis inhibitors in CNS diseases to provide new targets and clini-cal references for CNS disease treatment.