الملخص
El tratamiento con implantes dentales hoy en día es un procedimiento clínico de rutina que permite rehabilitar a los pacientes con prótesis fijas. En este caso presentamos un tratamiento complejo de implantación inmediata del sector anterior con pérdida parcial de la cortical vestibular en el que se realizó una regeneración ósea guiada y provisionalización en un tiempo quirúrgico en un paciente con patología renal. Complementamos el estudio con una revisión de la efectividad de las técnicas utilizadas y las posibles respuestas celular asociadas a la patología renal.
Treatment with dental implants nowadays is a routine clinical procedure that allows patient rehabilitation with fixed prostheses. In this case we present a complex treatment of immediate implantation of the anterior sector with partial loss of the vestibular cortex, in which guided bone regeneration and provisionalization was performed in surgical time in a patient with kidney pathology. The study was complemented with a review of the effectiveness of the techniques used and the possible cellular responses associated with kidney pathology.
الملخص
SUMMARY: Tissue engineering aims to fabricate a scaffold that exhibits a suitable surface topography for a desired cellular response. Therefore, a study analyzing the characteristics of bone grafts is important for future research directions. This work aims to analyze the physical-chemical characteristics of commercially available bone grafts of human and bovine origin for dental use, using morphological analysis of the surface and chemical composition by variable pressure scanning electron microscope (VP-SEM) and energy-dispersive x-ray (EDX) spectrometry. In addition, pore diameter and surface area were analyzed by degassing method using a porosimeter, and particle size by laser diffraction. The analyzed allograft and xenograft particles differ in morphological characteristics and chemical composition. The allograft particles present a cuboidal and prismatic geometric morphology with angled edges and the absence of macropores. On the contrary, the xenograft particles present an irregular morphology with macropores in their structure. There is a statistically significant difference in C, P, and Ca between the xenograft and allografts (p < 0,05). The analyzed composition of allografts showed mainly the presence of C and O. In contrast, the composition of the xenograft was mainly Ca. These differences could influence the osteogenic properties of allografts and xenografts. This analysis provides basic information to understand the physicochemical properties of allografts and xenografts that facilitate cell-graft interaction.
La ingeniería de tejidos tiene como objetivo fabricar un andamio que muestre una topografía de superficie adecuada para una respuesta celular deseada. Por tanto, un estudio que analice las características de los injertos óseos es importante para futuros enfoques de investigación. Este trabajo tiene como objetivo analizar las características físico-químicas de injertos óseos de origen humano y bovino disponibles comercialmente para uso odontológico, mediante análisis morfológico de la superficie y composición química mediante microscopio electrónico de barrido de presión variable (VP-SEM) y x-dispersivo de energía. espectrometría de rayos (EDX). Además, el diámetro de los poros y el área superficial se analizaron mediante el método de desgasificación utilizando un porosímetro y el tamaño de las partículas mediante difracción láser. Las partículas de aloinjerto y xenoinjerto analizadas difieren en características morfológicas y composición química. Las partículas del aloinjerto presentan una morfología geométrica cúbica y prismática con bordes angulados y ausencia de macroporos. Por el contrario, las partículas de xenoinjerto presentan una morfología irregular con macroporos en su estructura. Existe una diferencia estadísticamente significativa en C, P y Ca entre el xenoinjerto y los aloinjertos (p < 0,05). La composición analizada de los aloinjertos mostró principalmente la presencia de C y O. Por el contrario, la composición del xenoinjerto fue principalmente Ca. Estas diferencias podrían influir en las propiedades osteogénicas de los aloinjertos y xenoinjertos. Este análisis proporciona información básica para comprender las propiedades fisicoquímicas de aloinjertos y xenoinjertos que facilitan la interacción célula-injerto.
الموضوعات
Humans , Animals , Cattle , Allografts/anatomy & histology , Allografts/chemistry , Spectrometry, X-Ray Emission , Bone Regeneration , Microscopy, Electron, Scanning , Porosity , Bone Transplantation , Heterografts/anatomy & histology , Heterografts/chemistryالملخص
Los quistes de los maxilares son las lesiones óseas más comunes en la región maxilofacial. La enucleación de las lesiones y el cierre primario de los defectos, son en conjunto, el tratamiento óptimo hoy en día. En algunas ocasiones el defecto óseo resultante puede ser de un tamaño tan grande que afecta la estabilidad de dientes vecinos, comprometa la indemnidad del hueso o produce un retraso cicatrizal que incluso puede impedir una regeneración ósea completa. Se considera que esta falta de regeneración expone al paciente a riesgos de infección tardía, retraso de los tratamientos rehabilitadores en zonas de alta demanda estética y pérdida de vitalidad dentaria. Para disminuir el riesgo de alteraciones en la regeneración ósea completa de cavidades quísticas, se ha propuesto la posibilidad de que tras la enucleación del quiste se rellenen estos defectos con injertos óseos u otras técnicas de preservación alveolar para favorecer la cicatrización. Teóricamente el uso de estos injertos mejora la calidad y disminuye el tiempo de cicatrización ósea, permitiendo que el paciente recupere rápidamente las funciones habituales del componente dentoalveolar, acortando el periodo de cuidados postoperatorios que restringen la alimentación, los deportes o la rehabilitación oral. El actual trabajo tiene como objetivo realizar una revisión de la literatura respecto a los beneficios del uso de injertos óseos en el tratamiento quirúrgico de los quistes maxilares y presentar un caso clínico con los detalles quirúrgicos de esta técnica.
Jaw cysts are the most common bone lesions in the maxillofacial region. Enucleation of the lesions along with the primary closure of the defects are the optimal treatment nowadays. On some occasions, the resulting bone defect can be so large that it affects the stability of neighboring teeth, compromises the integrity of the bone, or produces a delayed healing that can even prevent complete bone regeneration. It is considered that the lack of regeneration exposes the patient to risk of infection, delay of rehabilitation treatments in areas of high aesthetic demand and loss of dental vitality. To reduce the risk of alterations in complete bone regeneration of cystic cavities, the possibility of filling these defects with bone grafts or other alveolar preservation techniques to promote healing, has been proposed after cyst enucleation. Theoretically, the use of these grafts improves the quality and decreases the bone healing time, allowing the patient to quickly recover the usual functions of the dentoalveolar component, limiting the period of postoperative care that restricts eating, sports or oral rehabilitation. The present work aims to carry out a review of the literature regarding the benefits of the use of bone grafts in the surgical treatment of maxillary cysts and to present a clinical case with the surgical details of this technique.
الملخص
El fibroma ameloblástico (FA) se describe como una neoplasia benigna de origen odontogénico mixto que suele presentarse entre la primera y segunda década de vida, frecuentemente en los molares permanentes inferiores. Por lo general es asintomático, pero las lesiones de gran tamaño suelen acompañarse con dolor e inflamación. Su tratamiento por lo regular es conservador. Se describe el caso de un fibroma ameloblástico en un paciente de 13 años de edad, que involucraba cuerpo y ángulo mandibular izquierdo, tratado de manera conservadora, se realiza extirpación del tumor, regeneración ósea guiada y rehabilitación con implante dental (AU)
Ameloblastic fibroma (AF) is described as a benign neoplasm of mixed odontogenic origin that usually presents between the first and second decade of life, frequently in lower permanent molars. It is usually asymptomatic, but large lesions are usually accompanied by pain and inflammation. His treatment is generally conservative. The clinical case of an ameloblastic fibroma in a 13-year-old patient is described, involving the left mandibular body and angle, treated conservatively, tumor removal, guided bone regeneration and rehabilitation with dental implants are performed (AU)
الموضوعات
Humans , Male , Adolescent , Bone Regeneration , Mandibular Neoplasms/surgery , Odontogenic Tumors/classification , Fibroma/surgery , Prognosis , Dental Implantation, Endosseous/methods , Diagnosis, Differential , Fibroma/rehabilitationالملخص
Abstract Bone regeneration is crucial for repairing bone tissue following various injuries. Research techniques that enable the study of metabolic changes in bone tissue under different conditions are important for understanding bone repair and remodeling. This study used bone scintigraphy to evaluate osteogenesis secondary to osteotomy in a preclinical model of New Zealand rabbits. For this purpose, we conducted a longitudinal, prospective, case-control study in which scintigraphic variables were measured in both the right forearm (case-operated) and the left forearm (control - non-operated). The study sample consisted of 10 rabbits subjected to osteotomy, followed by a 12-week postoperative evaluation period, divided into six imaging stages at 1, 2, 3, 4, 8, and 12 weeks. We observed that the operated forearm showed significantly higher external radiation than the control side, using the pinhole collimator, denoting an increase in the biodistribution and tropism of the radiopharmaceutical to the operated forearm. Among the three evaluated time points, osteoblastic activity was highest in the second week and presented a significant decline in the 8th and 12th weeks, denoting regeneration and resolution of the surgical injury; the control forearm was also influenced by the inactivity imposed by the operated forearm. This fact was notably evidenced by the reduction in the metabolic activity of osteoblasts in the left forearm. Our study suggested that bone scintigraphy was sensitive enough to semi-quantitatively differentiate the metabolic activity of osteoblasts in the operated forearm in the three temporal landmarks evaluated in the study.
الملخص
Oral diseases concern almost every individual and are a serious health risk to the popula-tion.The restorative treatment of tooth and jaw defects is an important means to achieve oral function and support the appearance of the contour.Based on the principle of"learning from the nature",Deng Xu-liang's group of Peking University School and Hospital of Stomatology has proposed a new concept of"microstructural biomimetic design and tissue adaptation of tooth/jaw materials"to address the worldwide problems of difficulty in treating dentine hypersensitivity,poor prognosis of restoration of tooth defects,and vertical bone augmentation of alveolar bone after tooth loss.The group has broken through the bottle-neck of multi-stage biomimetic technology from the design of microscopic features to the enhancement of macroscopic effects,and invented key technologies such as crystalline/amorphous multi-level assembly,ion-transportation blocking,and multi-physical properties of the micro-environment reconstruction,etc.The group also pioneered the cationic-hydrogel desensitizer,digital stump and core integrated restora-tions,and developed new crown and bridge restorative materials,gradient functionalisation guided tissue regeneration membrane,and electrically responsive alveolar bone augmentation restorative membranes,etc.These products have established new clinical strategies for tooth/jaw defect repair and achieved inno-vative results.In conclusion,the research results of our group have strongly supported the theoretical im-provement of stomatology,developed the technical system of oral hard tissue restoration,innovated the clinical treatment strategy,and led the progress of the stomatology industry.
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Objective:To investigate the characteristics and risk factors of perioperative hypertension during dental implant surgeries with bone augmentation.Methods:A retrospective cohort study was con-ducted.Seven hundred and twenty-eight cases underwent dental implant placement and bone augmenta-tion in Peking University School and Hospital of Stomatology from September 2021 to August 2022 were recruited in this study according to the inclusion and exclusion criteria.They were divided into different groups according to the exposure factors which were gender,age,surgical time,and surgical approach.The correlation between perioperative hypertension and the exposure factors was analyzed.Results:The average systolic blood pressure variability was 9.93％±6.63％(maximum 50.41％),the average dias-tolic blood pressure variability was 12.45％±8.79％(maximum 68.75％),and the average mean arte-rial pressure variability was 10.02％±6.61％(maximum 49.48％).The incidence rate of perioperative hypertension was 26.77％.Male,age ≥ 60 years,and surgical time＞60 minutes were risk factors for perioperative hypertension(P＜0.05),and the relative risks(95％CI)were 1.74(1.21-2.50),2.35(1.54-3.58),and 1.65(1.15-2.38),respectively.There was no significant difference in the inci-dence of perioperative hypertension among the guided bone regeneration,sinus floor elevation with transal-veolar approach,and sinus floor elevation with lateral window approach(P＞0.05).However,the risk factors varied according to bone augmentation approaches.For the patients underwent guided bone rege-neration,the risk factors for perioperative hypertension included male,age≥60 years,and surgical time＞60 minutes(P＜0.05).For the patients underwent maxillary sinus lift with transalveolar approach,the risk factor for perioperative hypertension was age ≥ 60 years(P＜0.05).For the patients underwent maxillary sinus lift with lateral window approach,male,age ≥60 years,and surgical time＞60 minutes were not risk factors for perioperative hypertension(P＞0.05).Conclusion:There was a certain risk of periopera-tive hypertension in oral implantation with bone augmentation.The influence of male,age ≥60 years and sur-gical time＞60 minutes on perioperative hypertension was related to the approach of bone augmentation.
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BACKGROUND:With the proven ability of traditional Chinese medicine such as icariin and berberine to promote bone regeneration by regulating various mechanisms and targets,researchers have combined active ingredients of traditional Chinese medicine with bone tissue engineering and found that they have unique advantages in treating bone defects. OBJECTIVE:Starting from the active ingredients of traditional Chinese medicines that promote bone formation,to screen cases of their effective combination with different drug-carrying scaffold materials,and summarize the active ingredients of traditional Chinese medicines that have the potential to be applied to bone tissue engineering. METHODS:CNKI,WanFang,PubMed,and Web of Science were searched for relevant literature published from 2000 to 2023,using the keywords of"bone tissue engineering,bone tissue-engineered scaffold materials,bone defect,bone repair,bone regeneration,traditional Chinese medicine"in Chinese and English.According to the inclusion and exclusion criteria,87 papers were finally included for review. RESULTS AND CONCLUSION:There are various kinds of active ingredients of traditional Chinese medicine to promote bone regeneration,mainly including flavonoids,non-flavonoid polyphenols,alkaloids,glycosides.These active ingredients have anti-inflammatory and analgesic effects,promote osteoblasts,inhibit osteoclasts and promote early angiogenesis.The combination of active ingredients of traditional Chinese medicine with bone tissue engineering is effective in anti-inflammation,accelerating collagen and bone formation,and promoting the expression of osteogenic genes,which provides a theoretical basis for the application of traditional Chinese medicine in bone tissue regeneration,and at the same time provides a new idea for the repair of bone defects.
الملخص
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.
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BACKGROUND:In the construction of guided bone regeneration membrane with biological function,a single material cannot meet the clinical needs due to its insufficient function,so the composite of multiple materials has become a trend of tissue repair engineering. OBJECTIVE:To prepare silk fibroin/bioactive glass composite fiber membranes by electrospinning technology,and to characterize the physicochemical properties and biocompatibility in vitro. METHODS:The solution of electrospinning was prepared by dissolving 0.8 g silk fibroin protein in 10 mL hexafluoro-isopropanol alcohol,and the nanofiber membrane of silk fibroin protein was prepared by electrospinning technology(denoted as SF fiber membrane).0.1,0.3,0.5,and 0.8 g of bioactive glass were added to the electrospinning solution,and the silk fibroin/bioactive glass composite fiber membrane was prepared by electrospinning technology(recorded as SF/1BG,SF/3BG,SF/5BG,and SF/8BG fiber membrane in turn).The physicochemical properties and biocompatibility of five groups of fiber membranes were characterized. RESULTS AND CONCLUSION:(1)The scanning electron microscopy results showed that nanofibers of the prepared composite membrane were smooth,continuous and uniform and had no beaded structure.There was no obvious adhesion between the silk fibers,and they all showed random arrangement of disordered porous structures.The fiber diameter of the fiber membrane decreased after the addition of bioactive glass.Fourier infrared spectroscopy and X-ray diffraction detection results showed that the chemical structure of silk fibroin protein and bioactive glass in fiber membrane was stable.The water contact angles of SF,SF/1BG,SF/3BG,SF/5BG,and SF/8BG were 105.02°,72.58°,78.13°,79.35°,and 72.50°,respectively.(2)Bone marrow mesenchymal stem cells were inoculated on five groups of fiber membranes.CCK-8 assay results showed that SF/1BG,SF/3BG,and SF/5BG fiber membranes could promote the proliferation of bone marrow mesenchymal stem cells compared with SF and SF/8BG.Live cell/dead cell staining showed that the cell vitality on the surface of the five groups of fiber membranes was better,and the number and distribution of cells on the surface of SF/5BG fiber membrane were more uniform.Rhodamine phalloidin staining and scanning electron microscopy exhibited that compared with SF fiber membrane,the SF/5BG fiber membrane was more favorable to the adhesion of bone marrow mesenchymal stem cells.Bone marrow mesenchymal stem cells were inoculated on the fiber membrane of the five groups for osteogenic induction differentiation,and the alkaline phosphatase activity of the SF/3BG and SF/5BG groups was higher than that of the other three groups(P＜0.05,P＜0.01,P＜0.001).Alizarin red staining showed that the formation of calcium nodules in fiber membrane increased after the addition of bioactive glass,and the formation of calcium nodules in the SF/5BG group was the most.(3)The results show that silk fibroin/bioactive glass composite fiber membrane has good biosafety and biocompatibility.
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BACKGROUND:Artificially synthesized hydroxyapatite ceramic granules are widely used in clinical practice to repair large-volume bone defects.However,the osteogenic effect of hydroxyapatite ceramic granules prepared by high-temperature sintering is limited by their low degradability and bioactivity. OBJECTIVE:To prepare biomimetically precipitated nanocrystalline calcium phosphate granules by a novel low-temperature deposition technique,and to characterize their physicochemical properties and cytocompatibility. METHODS:Biomimetically precipitated nanocrystalline calcium phosphate granules were prepared using a modified supersaturated calcium phosphate mineralization solution and a repeated settling and decantation washing method.Hydroxyapatite bioceramic granules were used as the control.The morphology and phase composition of the granules were characterized by scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy.The specific surface area,porosity distribution,hardness and hydrophilicity of the granules were characterized by BET-N2 method,hardness test,and contact angle test.The adsorption properties of the granules for bovine serum albumin and fetal bovine serum protein were determined by bicinchoninic acid assay.The two kinds of granules or granule extracts were co-cultured with human umbilical cord mesenchymal stem cells,and the cell proliferation was detected by MTT assay. RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that the surface of the two kinds of particles was slightly rough and accompanied by tiny particles,the surface of the hydroxyapatite bioceramic particles was dense and smooth,and the biomimetically precipitated nanocrystalline calcium phosphate granules were mainly composed of needle/plate crystals with non-uniform nanometer size,and formed a nanopore structure between the crystals.X-ray diffraction and Fourier transform infrared spectroscopy exhibited that compared with hydroxyapatite bioceramic granules,biomimetically precipitated nanocrystalline calcium phosphate granules had smaller crystalline particles,lower crystallinity,and more binding water and carbonic acid groups.Compared with hydroxyapatite bioceramic granules,biomimetically precipitated nanocrystalline calcium phosphate granules had higher specific surface area,better hydrophilicity,lower hardness,and higher protein adsorption capacity.(2)The results of MTT assay showed that the two kinds of granule extracts had no cytotoxicity,human umbilical cord mesenchymal stem cells survived well on the surface of the two kinds of granules,and the biomimetically precipitated nanocrystalline calcium phosphate granules had stronger cell proliferation activity.(3)These findings indicate that compared with hydroxyapatite bioceramic granules,biomimetically precipitated nanocrystalline calcium phosphate granules have better physicochemical properties and cytocompatibility.
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BACKGROUND:Polylactic acid has good biocompatibility and biodegradability,and has become a new orthopedic fixation material.However,the lack of cell recognition signal of this material is not conducive to cell adhesion and osteogenic differentiation,which limits its application in biomaterials. OBJECTIVE:3D-printed polylactic acid-nano-hydroxyapatite(nHA)/chitosan(CS)scaffold to evaluate its drug sustained-release and biological properties. METHODS:The porous polylactic acid scaffold(recorded as PLA scaffold)with interporous pores was printed by fused deposition modeling technique,and the scaffold was soaked in dopamine solution to prepare polylactic acid-dopamine scaffold(recorded as PLA-DA scaffold).Nano-hydroxyapatite was immersed in chitosan solution,and then the PLA-DA scaffold was immersed in it to prepare polylactic acid-nano-hydroxyapatite/chitosan scaffold(recorded as PLA-nHA/CS scaffold).The micro-morphology,porosity,water contact angle,and compressive strength of the three scaffolds were characterized.PLA-nHA/CS scaffold loaded with doxycycline(recorded as PLA-nHA/CS-DOX scaffold)was prepared by freeze-drying method,and its drug release was characterized.PLA,PLA-DA,PLA-nHA/CS,and PLA-nHA/CS-DOX scaffolds were co-cultured with MC3T3-E1 cells,separately,to detect cell proliferation and osteogenic differentiation.Staphylococcus aureus suspensions of different concentrations were co-cultured with four groups of scaffolds.The antibacterial performance of scaffolds was detected by inhibition zone test. RESULTS AND CONCLUSION:(1)Under scanning electron microscopy,the surfaces of PLA and PLA-DA scaffolders were dense and smooth,and nHA particles were observed on PLA-nHA/CS scaffolders.The porosity of PLA,PLA-DA and PLA-nHA/CS scaffolds decreased gradually,and the compressive strength increased gradually.The elastic modulus of PLA-nHA/CS scaffolds met the requirements of cancelous bone.The water contact angle of PLA-DA and PLA-nHA/CS brackets was smaller than that of PLA scaffolds.The PLA-nHA/CS scaffold sustainably released drugs in vitro for 8 days.(2)CCK-8 assay showed that the proliferation of MC3T3-E1 cells was not significantly affected by the four groups of scaffolds.The activity of alkaline phosphatase in PLA-DA group,PLA-nHA/CS group,and PLA-nHA/CS-DOX group was higher than that in PLA group.Alizarin red staining showed that compared with PLA group,the cells in PLA-nHA/CS group and PLA-nHA/CS-DOX group showed higher mineralized water level.(3)Inhibition zone test exhibited that PLA and PLA-DA scaffolds had no antibacterial properties.PLA-nHA/CS scaffolds had certain antibacterial properties.PLA-nHA/CS-DOX scaffolds had super antibacterial properties.(4)The results showed that the PLA-nHA/CS-DOX scaffold had good drug release performance,cell compatibility,osteogenic properties,and antibacterial properties.
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BACKGROUND:Bone has bioelectric effects.However,bone defects can lead to loss of endogenous bioelectricity in bone.The implantation of bone tissue engineering scaffolds with bioelectric effect into bone defects will replenish the missing electrical signals and accelerate the repair of bone defects. OBJECTIVE:To introduce the bioelectric effect of bone tissue and expound the repair effect of electrical stimulation on bone defects,summarize the research progress of bioelectric effect applied to bone tissue engineering,in order to provide new ideas for the research of bone tissue engineering. METHODS:Relevant articles were searched on CNKI,WanFang,PubMed,Web of Science and ScienceDirect databases,using"bioelectrical effect,bioelectrical materials,electrical stimulation,bone tissue engineering,bone scaffold,bone defect,bone repair,osteogenesis"as the English and Chinese search terms.Finally,87 articles were included for analysis. RESULTS AND CONCLUSION:(1)Bioelectrical effect combined with ex vivo electrical stimulation to design bone tissue engineering scaffolds is an ideal and feasible approach,and the main materials involved include metallic materials,graphene materials,natural bio-derived materials,and synthetic biomaterial.At present,the most widely used conductive material is graphene material,which benefits from its super conductivity,large specific surface area,good biocompatibility with cells and bones,and excellent mechanical properties.(2)Graphene materials are mainly introduced into the scaffold as modified materials to enhance the conductivity of the overall scaffold,while its large surface area and rich functional groups can promote the loading and release of bioactive substances.(3)However,there are still some major challenges to overcome for bioelectrically effective bone tissue engineering scaffolds:not only electrical conductivity but also the overall performance of the bracket needs to be considered;lack of uniform,standardized preparation of bioelectrically effective bone tissue engineering scaffolds;extracorporeal electrical stimulation intervention systems are not yet mature enough;lack of individualized guidance on stent selection to enable the selection and design of the most appropriate stent for patients with different pathologies.(4)When designing conductive scaffolds,researchers have to deeply consider the comprehensive effects of the scaffolds,such as biocompatibility,mechanical properties,and biodegradability.This combination of properties can be achieved by combining multiple materials.(5)Beyond that,clinical translation should be the ultimate consideration for conductive stent design.On the basis of evaluating the safe current threshold for electrical stimulation to act on the human body and facilitate the repair of bone defects,animal experiments as well as basic experiments are designed and then applied to the clinic to achieve the ultimate goal of applying bioelectrical effect bone tissue engineering scaffolds in the clinic.
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BACKGROUND:Berberine has the potential to induce osteogenic differentiation of various mesenchymal stem cells under normal conditions and special conditions such as high glucose,infection and inflammation.It is a natural small molecule drug that can induce bone formation in seed cells instead of growth factors,and has great application prospect in bone tissue engineering. OBJECTIVE:To review and summarize the research progress in the osteogenic mechanism and efficacy of berberine,especially its osteogenic potential under high glucose,infection and inflammation conditions,and its biological safety,so as to provide theoretical basis for its development and application in bone tissue engineering. METHODS:PubMed,WanFang,and CNKI were searched for relevant literature using the keywords of"berberine,bone defects,bone repair,bone regeneration,osteoinductive,osteoporosis,osteoblast,osteoclast,bone tissue engineering,bone,high glucose,diabetes,inflam*,infect*"in English and Chinese,respectively.A total of 105 literatures were selected for review. RESULTS AND CONCLUSION:Berberine can be used to treat multiple diseases including bone diseases,and it has the ability to promote bone regeneration.This article systematically reviews the mechanism of berberine on bone regeneration and in vivo and in vitro studies.Studies have shown that it can play a role in bone repair by promoting osteogenesis,inhibiting osteoclast formation and activity,and preventing osteoporosis.It shows excellent osteogenic differentiation potential mainly via Wnt/β-catenin,PI3K/AKT,EGFR/MEK/p38MAPK,cAMP/PKA/CREB,ERK and other signaling pathways.Berberine can also relieve the inhibition of osteogenic differentiation caused by high glucose,infection and inflammation,which provides more possibilities for the treatment of bone defects in patients with diabetes or infection and inflammation in the bone defect site.Berberine also has the advantages of low toxicity,low price,easy access(currently it can be synthesized),which is a relatively ideal bone induction potential drug.In recent years,the application of berberine in the treatment of bone defect tends to be localized,mainly through the combination with bone tissue engineering technology to improve bioavailability,and has shown good bone repair effect and excellent biological safety in animal experiments.In addition,preclinical experiments have shown splendid bone regeneration potential in the conditions of diabetes,local infection and inflammation.In the future,more studies are needed to fully reveal the osteogenic mechanism and biological safety of berberine,and seek the most suitable controlled release loading system to make artificial bone replacement materials with good mechanical strength,efficacy and biological safety.
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Objective To investigate the clinical effect of apical microsurgery combined with guided bone regeneration(GBR)on refractory apical periodontitis and masticatory function.Methods A total of 82 patients with refractory apical periodontitis admitted to our hospital from June 2019 to September 2021 were selected as the study subjects,and they were divided into the control group and the com-bined group according to the random number table,with 41 cases in each group.The control group was treated with apical microsurgery,and the combined group was treated with apical microsurgery combined with GBR.The clinical efficacy,masticatory function and the levels of bone absorption markers[Wnt3a,osteoprotegerin(OPG),receptor activator of nuclear factor-κB ligand(RANKL)]of patients in the two groups were compared.Results The total effective rate of the combined group(100%)was higher than that of the control group(85.37%),the difference was statistically significant(P<0.05).The masticatory efficiency and bite force of patients in both groups increased gradually 3,6 and 12 months after operation(P<0.05),which were higher in the combined group compared with the control group(P<0.05).The tooth mobility of patients in both groups decreased gradually 3,6 and 12 months after operation,and the tooth mobility of patients 3 and 6 months after operation in the combined group were lower than those in the control group(P<0.05).The levels of Wnt3a and OPG of patients 1 week after operation in both groups increased,which were higher in the combined group compared with the control group(P<0.05).The RANKL level of gingival crevicular fluid of patients 1 week after operation in both groups decreased,and which was lower in the combined group compared with the control group(P<0.05).Conclusion The microapical surgery combined with GBR is effective for refractory apical periodontitis,which can effectively inhibit bone resorption,and improve masticatory function.
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@#Graphene family nanomaterials (GFNs) are highly popular in the field of bone tissue engineering because of their excellent mechanical properties, biocompatibility, and ability to promote the osteogenic differentiation of stem cells. GFNs play a multifaceted role in promoting the bone regeneration microenvironment. First, GFNs activate the adhesion kinase/extracellularly regulated protein kinase (FAK/ERK) signaling pathway through their own micromorphology and promote the expression of osteogenesis-related genes. Second, GFNs adapt to the mechanical strength of bone tissue, which helps to maintain osseointegration; by adjusting the stiffness of the extracellular matrix, they transmit the mechanical signals of the matrix to the intracellular space with the help of focal adhesions (FAs), thus creating a favorable physiochemical microenvironment. Moreover, they regulate the immune microenvironment at the site of bone defects, thus directing the polarization of macrophages to the M2 type and influencing the secretion of relevant cytokines. GFNs also act as slow-release carriers of bioactive molecules with both angiogenic and antibacterial abilities, thus accelerating the repair process of bone defects. Multiple types of GFNs regulate the bone regeneration microenvironment, including scaffold materials, hydrogels, biofilms, and implantable coatings. Although GFNs have attracted much attention in the field of bone tissue engineering, their application in bone tissue regeneration is still in the basic experimental stage. To promote the clinical application of GFNs, there is a need to provide more sufficient evidence of their biocompatibility, elucidate the mechanism by which they induce the osteogenic differentiation of stem cells, and develop more effective form of applications.
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@#The identification of suitable seed cells represents a critical scientific problem to be solved in the field of oral and maxillofacial bone tissue regeneration. The application of adipose-derived stem cells (ASCs) in tissue and organ repair and regeneration has been studied extensively. In recent years, dedifferentiated fat (DFAT) cells have also shown broad application prospects in the field of bone tissue engineering. DFAT cells express stem cell-related markers and have the potential to differentiate into adipocytes, osteoblasts, chondrocytes, nerve cells, cardiomyocytes and endothelial cells. In addition, DFAT cells also have the advantages of minimally invasive acquisition, strong proliferation and high homogeneity. Currently, all studies involving the application of DFAT cells in scaffold-based and scaffold-free bone tissue engineering can confirm their effectiveness in promoting bone regeneration. However, cytological research still faces some challenges, including relatively low cell culture purity, unclear phenotypic characteristics and undefined dedifferentiation mechanisms. It is believed that with the continuous development and improvement of isolation, culture, identification and directional induction of osteogenic differentiation methods, DFAT cells are expected to become excellent seed cells in the field of oral and maxillofacial bone tissue engineering in the future.
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Objective@#To investigate the osteogenic properties of a methacrylated gelatin (GelMA) / bone marrow mesenchymal stem cells (BMSCs) composite hydrogel applied to the skull defect area of rats and to provide an experimental basis for the development of bone regeneration biomaterials.@*Methods@#This study was approved by the Animal Ethics Committee of Nanjing University. A novel photocurable composite biohydrogel was developed by constructing photoinitiators [lthium phenyl (2,4,6-trimethylbenzoyl) phosphinate, LAP], GelMA, and BMSCs. The surface morphology and elemental composition of the gel were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The compressive strength of the gel was evaluated using an electronic universal testing machine. After in vitro culture for 1, 2, and 5 days, the proliferation of the BMSCs in the hydrogels was assessed using a CCK-8 assay, and their survival and morphology were examined through confocal microscopy. A 5 mm critical bone deficiency model was generated in a rat skull. The group receiving composite hydrogel treatment was referred to as the GelMA/BMSCs group, whereas the untreated group served as the control group. At the 4th and 8th weeks, micro-CT scans were taken to measure the bone defect area and new bone index, while at the 8th week, skull samples from the defect area were subjected to H&E staining, van Gieson staining, and Goldner staining to evaluate the quality of bone regeneration and new bone formation.@*Results@#SEM observed that the solidified GelMA showed a 3D spongy gel network with uniform morphology, the porosity of GelMA was 73.41% and the pore size of GelMA was (28.75 ± 7.13) μm. EDX results showed that C and O were evenly distributed in the network macroporous structure of hydrogel. The hydrogel compression strength was 152 kPa. On the 5th day of GelMA/BMSCs culture, the cellular morphology transitioned from oval to spindle shaped under microscopic observation, accompanied by a significant increase in cell proliferation (159.4%, as determined by the CCK-8 assay). At 4 weeks after surgery, a 3D reconstructed micro-CT image revealed a minimal reduction in bone defect size within the control group and abundant new bone formation in the GelMA/BMSCs group. At 8 weeks after surgery, no significant changes were observed in the control group's bone defect area, with only limited evidence of new bone growth; however, substantial healing of skull defects was evident in the GelMA/BMSCs group. Quantitative analysis at both the 4- and 8-week examinations indicated significant improvements in the new bone volume (BV), new bone volume/total bone volume (BV/TV), bone surface (BS), and bone surface/total bone volume (BS/TV) in the GelMA/BMSCs group compared to those in the control group (P<0.05). Histological staining showed continuous and dense formation of bone tissue within the defects in the GelMA/BMSCs group and only sporadic formation of new bone, primarily consisting of fibrous connective tissue, at the defect edge in the control group.@*Conclusion@#Photocuring hydrogel-based stem cell therapy exhibits favorable biosafety profiles and has potential for clinical application by inducing new bone formation and promoting maturation within rat skull defects.
الملخص
Magnesium-doped calcium silicate (CS) bioceramic scaffolds have unique advantages in mandibular defect repair; however, they lack antibacterial properties to cope with the complex oral microbiome. Herein, for the first time, the CS scaffold was functionally modified with a novel copper-containing polydopamine (PDA(Cu2+)) rapid deposition method, to construct internally modified (*P), externally modified (@PDA), and dually modified (*P@PDA) scaffolds. The morphology, degradation behavior, and mechanical properties of the obtained scaffolds were evaluated in vitro. The results showed that the CS*P@PDA had a unique micro-/nano-structural surface and appreciable mechanical resistance. During the prolonged immersion stage, the release of copper ions from the CS*P@PDA scaffolds was rapid in the early stage and exhibited long-term sustained release. The in vitro evaluation revealed that the release behavior of copper ions ascribed an excellent antibacterial effect to the CS*P@PDA, while the scaffolds retained good cytocompatibility with improved osteogenesis and angiogenesis effects. Finally, the PDA(Cu2+)-modified scaffolds showed effective early bone regeneration in a critical-size rabbit mandibular defect model. Overall, it was indicated that considerable antibacterial property along with the enhancement of alveolar bone regeneration can be imparted to the scaffold by the two-step PDA(Cu2+) modification, and the convenience and wide applicability of this technique make it a promising strategy to avoid bacterial infections on implants.
الموضوعات
Animals , Rabbits , Copper/pharmacology , Tissue Scaffolds/chemistry , Bone Regeneration , Anti-Bacterial Agents/pharmacology , Osteogenesis , Calcium , Ions/pharmacologyالملخص
Objective@#To evaluate the bone repair effect of 3D-printed magnesium (Mg)-loaded polycaprolactone (PCL) scaffolds in a rat skull defect model.@*Methods@#PCL scaffolds mixed with Mg microparticles were prepared by using 3D printing technology, as were pure PCL scaffolds. The surface morphologies of the two scaffolds were observed by scanning electron microscopy (SEM), and the surface elemental composition was analyzed via energy dispersive spectroscopy (EDS). The physical properties of the scaffolds were characterized through contact angle measurements and an electronic universal testing machine. This study has been reviewed and approved by the Ethics Committee. A critical size defect model was established in the skull of 15 Sprague-Dawley (SD) rats, which were divided into the PCL group, PCL-Mg group, and untreated group, with 5 rats in each group. Micro-CT scanning was performed to detect and analyze skull defect healing at 4 and 8 weeks after surgery, and samples from the skull defect area and major organs of the rats were obtained for histological staining at 8 weeks after surgery.@*Results@#The scaffolds had a pore size of (480 ± 25) μm, a fiber diameter of (300 ± 25) μm, and a porosity of approximately 66%. The PCL-Mg scaffolds contained 1.0 At% Mg, indicating successful incorporation of Mg microparticles. The contact angle of the PCL-Mg scaffolds was 68.97° ± 1.39°, indicating improved wettability compared to that of pure PCL scaffolds. Additionally, compared with that of pure PCL scaffolds, the compressive modulus of the PCL-Mg scaffolds was (57.37 ± 8.33) MPa, demonstrating enhanced strength. The PCL-Mg group exhibited the best bone formation behavior in the skull defect area compared with the control group and PCL group at 4 and 8 weeks after surgery. Moreover, quantitative parameters, such as bone volume (BV), bone volume/total volume (BV/TV), bone surface (BS), bone surface/total volume (BS/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) and bone mineral density (BMD), of skull defects were better than those in the other groups, indicating the best bone regeneration effect. H&E, Goldner, and VG staining revealed more mineralized new bone formation in the PCL-Mg group than in the other groups, and H&E staining of the major organs revealed good biosafety of the material.@*Conclusion@#PCL-Mg scaffolds can promote the repair of bone defects and have clinical potential as a new scaffold material for the repair of maxillofacial bone defects.