Conditioned medium from human dental pulp stem cells treats spinal cord injury by inhibiting microglial pyroptosis

Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.

RPLP0/TBP are the most stable reference genes for human dental pulp stem cells under osteogenic differentiation

BACKGROUND Validation of the reference gene(RG)stability during experimental analyses is essential for correct quantitative real-time polymerase chain reaction(RT-qPCR)data normalisation.Commonly,in an unreliable way,several studies use genes involved in essential cellular functions[glyceraldehyde-3-phosphate dehydro-genase(GAPDH),18S rRNA,andβ-actin]without paying attention to whether they are suitable for such experimental conditions or the reason for choosing such genes.Furthermore,such studies use only one gene when Minimum Information for Publication of Quantitative Real-Time PCR Experiments guidelines recom-mend two or more genes.It impacts the credibility of these studies and causes dis-tortions in the gene expression findings.For tissue engineering,the accuracy of gene expression drives the best experimental or therapeutical approaches.We cultivated DPSCs under two conditions:Undifferentiated and osteogenic dif-ferentiation,both for 35 d.We evaluated the gene expression of 10 candidates for RGs[ribosomal protein,large,P0(RPLP0),TATA-binding protein(TBP),GAPDH,actin beta(ACTB),tubulin(TUB),aminolevulinic acid synthase 1(ALAS1),tyro-sine 3-monooxygenase/tryptophan 5-monooxygenase activation protein,zeta(YWHAZ),eukaryotic translational elongation factor 1 alpha(EF1a),succinate dehydrogenase complex,subunit A,flavoprotein(SDHA),and beta-2-micro-globulin(B2M)]every 7 d(1,7,14,21,28,and 35 d)by RT-qPCR.The data were analysed by the four main algorithms,ΔCt method,geNorm,NormFinder,and BestKeeper and ranked by the RefFinder method.We subdivided the samples into eight subgroups.RESULTS All of the data sets from clonogenic and osteogenic samples were analysed using the RefFinder algorithm.The final ranking showed RPLP0/TBP as the two most stable RGs and TUB/B2M as the two least stable RGs.Either theΔCt method or NormFinder analysis showed TBP/RPLP0 as the two most stable genes.However,geNorm analysis showed RPLP0/EF1αin the first place.These algorithms’two least stable RGs were B2M/GAPDH.For BestKeeper,ALAS1 was ranked as the most stable RG,and SDHA as the least stable RG.The pair RPLP0/TBP was detected in most subgroups as the most stable RGs,following the RefFinfer ranking.CONCLUSION For the first time,we show that RPLP0/TBP are the most stable RGs,whereas TUB/B2M are unstable RGs for long-term osteogenic differentiation of human DPSCs in traditional monolayers.

Self-assembly of differentiated dental pulp stem cells facilitates spheroid human dental organoid formation and prevascularization

BACKGROUND The self-assembly of solid organs from stem cells has the potential to greatly expand the applicability of regenerative medicine.Stem cells can self-organise into microsized organ units,partially modelling tissue function and regeneration.Dental pulp organoids have been used to recapitulate the processes of tooth development and related diseases.However,the lack of vasculature limits the utility of dental pulp organoids.AIM To improve survival and aid in recovery after stem cell transplantation,we demonstrated the three-dimensional(3D)self-assembly of adult stem cell-human dental pulp stem cells(hDPSCs)and endothelial cells(ECs)into a novel type of spheroid-shaped dental pulp organoid in vitro under hypoxia and conditioned medium(CM).METHODS During culture,primary hDPSCs were induced to differentiate into ECs by exposing them to a hypoxic environment and CM.The hypoxic pretreated hDPSCs were then mixed with ECs at specific ratios and conditioned in a 3D environment to produce prevascularized dental pulp organoids.The biological characteristics of the organoids were analysed,and the regulatory pathways associated with angiogenesis were studied.RESULTS The combination of these two agents resulted in prevascularized human dental pulp organoids(Vorganoids)that more closely resembled dental pulp tissue in terms of morphology and function.Single-cell RNA sequencing of dental pulp tissue and RNA sequencing of Vorganoids were integrated to analyse key regulatory pathways associated with angiogenesis.The biomarkers forkhead box protein O1 and fibroblast growth factor 2 were identified to be involved in the regulation of Vorganoids.CONCLUSION In this innovative study,we effectively established an in vitro model of Vorganoids and used it to elucidate new mechanisms of angiogenesis during regeneration,facilitating the development of clinical treatment strategies.

Multiple pulp stones emerge across all teeth during mixed dentition:A case report

BACKGROUND This paper reports a rare presentation of multiple pulp stones(PSs)emerging in all teeth during mixed dentition.It offers valuable insights into the clinical diagnosis,treatment,and prognosis of multiple PSs,shedding light on their occurrence during the mixed dentition period.CASE SUMMARY A 10-year-old girl presented with repeated pain in the mandibular right posterior teeth.Intraoral examination revealed carious lesions,abnormal tooth shapes,and anomalies in tooth number.Radiographic examinations showed multiple PSs with diverse shapes,sizes,and quantities in all teeth,alongside anomalies in tooth shape and number.Root canal therapy was initiated,but the patient initially lacked timely follow-up.Upon return for treatment completion,an extracted tooth revealed irregular calculus within the pulp cavity.CONCLUSION This case underscores the importance of considering multiple PSs in mixed dentition,necessitating comprehensive evaluation and management strategies.

Optimizing hemicelluloses pre-extraction in eucalyptus kraft pulping:A pathway towards enhancing pulp mill biorefineries

A critical pathway towards enhancing pulp mill biorefineries is to integrate the extraction and utilization of hemicelluloses into the pulping processes.Hence,an industrial pre-extraction strategy for hemicelluloses targeting eucalyptus kraft pulping process was developed.Alkaline solution or pulping white liquor was used to pre-extract hemicelluloses before the actual pulping process.The response surface methodology(RSM)technique was applied to investigate the most suitable conditions to maximize the yield of these hemicelluloses while simultaneously minimizing the damage to pulp yields and properties.Temperature(105 to 155℃),alkali concentration(3%to 8%),sulfidity(20%to 30%)and retention time(19 to 221 min)were combined to evaluate their effects on hemicellulose yields and chemical structures.The optimal pre-extraction conditions identified in this work(5.75%NaOH concentration,25%sulfidity at 135℃for 60 min)successfully allowed recovering 4.8%of hemicelluloses(based on the wood dry mass)and limited damages to pulp yields and properties.The cellulose content in pulp can even be increased by about 10%.Hemicellulose emulsification properties were also evaluated,which were comparable to synthetic emulsifiers.This study provides an industrial pathway to effectively separate and utilize wood hemicelluloses from the pulping process,which has the potential to improve the economy and material utilization of pulp and paper mills.

Adrenaline in pulp capping treatment of reversible pulpitis

BACKGROUND The role of epinephrine in the treatment of pulp capping in patients with reversible pulpitis is not clear.AIM To explore the role of epinephrine in the treatment of pulp capping in patients with reversible pulpitis.METHODS A total of 100 patients with reversible pulpitis who were treated in Anhui Jieshou People's Hospital from January 2020 to December 2021 were included in the study.They were categorized into an observation group(n=50;treatment with adrenaline)and a control group(n=50;treatment with zinc oxide eugenol paste).The 24-h postoperative pain,regression time of gingival congestion and redness,clinical efficacy,and incidence of adverse reactions were compared between the groups.Patients were further categorized into the ineffective and effective treatment groups based on clinical efficacy.Logistic multiple regression analysis explored factors affecting the efficacy of pulp capping treatment.RESULTS A significant difference in 24-h postoperative pain was observed between the groups(P<0.05),with a higher proportion of grade I pain noted in the observation group than in the control group(P<0.01).The regression time of gingival congestion and swelling was lower in the observation group(2.61±1.44 d and 2.73±1.36 d,respectively)than in the control group(3.85±1.47 d and 4.28±1.61 d,respectively)(P<0.05).The 2-wk postoperative total effective rate was lower in the control group(80.00%)than in the observation group(94.00%)(P<0.05).The incidence of adverse reactions was not significantly different between the control(14.00%)and observation(12.00%)groups(P>0.05).The proportion of adrenaline usage was lower(P<0.05)and that of anaerobic digestion by Streptococcus and Fusobacterium nucleatum was higher in the ineffective treatment group than in the effective treatment group(P<0.05).Logistic multiple regression analysis revealed adrenaline as a protective factor(P<0.05)and anaerobic digestion by Streptococcus and F.nucleatum as risk factors for pulp capping in reversible pulpitis(P<0.05).CONCLUSION Adrenaline demonstrated therapeutic efficacy in pulp capping treatment for reversible pulpitis,reducing pain and improving clinical symptoms safely.It is a protective factor for pulp capping,whereas Streptococcus and F.nucleatum are risk factors.Targeted measures can be implemented to improve clinical efficacy.

Mono Ethanol Amine (MEA) Pulping of Wheat Straw: An Environmentally Friendly Suggestion for the Fluff Pulp Production

This research aimed to investigate the effect of pulping conditions and refining intensities of wheat straw to be recommended for fluff pulp production.For this purpose,mono ethanol amine(MEA)was selected as a de-lignification agent at three levels of 50:50,25:75,and 15:85(MEA/water,W/V%),and soda-AQ 14 W/V%was used as a reference pulping.To investigate the optimal refining intensity,the obtained pulp was passed through a single disk laboratory refiner from 0 to 6 times and in two different consistencies(1.5 and 2.5 W/V%).Total yield,kappa number,ash content,and the Schopper-Riegler(SR°)freeness of the prepared pulps were investigated.Finally,hand sheets with a targeted basic weight of 70 g/m^(2) were made according to the related standards.The hand sheets were characterized using Fourier transform infrared(FTIR)spectroscopy and a field emission scanning electron microscope(FE-SEM).Sheet density,brightness,and mechanical properties such as burst,tensile,and tear indices were also investigated.The FE-SEM photographs showed that the texture of the hand sheet became denser as the refining intensity increased.External fibrillation on the surface of the fibers was also observed,especially on those refined with 2.5%consistency.The results of the chemical composition of wheat straw indicated that wheat straw containing a high percentage of holocellulose is an excellent candidate for the production of fluff pulp.The total yield and kappa number of MEA pulps increased with the decrease in MEA concentration.FTIR results indicated the presence of a peak related to amino groups in the pulp related to MEA pulp.The results also indicated that the mechanical properties of the papers,except for the tear index,were enhanced as the intensity of refining and the pulp consistency during refining increased.

Formulation of Infant Flours Based on Fonio Enriched with Bambara Groundnut Anacardium (Cashew) and African Locust Bean Fruit Pulp

Infant malnutrition is a significant issue in Côte d’Ivoire, and this study aims to address it by formulating infant flours using local ingredients. Fermentation, germination, and malting methods were used to enhance the quality of six formulated flours, all based on Fonio and supplemented with Bambara groundnut, African locust bean fruit pulp, and cashew kernels. Results showed that Fonio had the highest carbohydrate content, while Bambara groundnut and Cashew kernels were rich in protein and lipid content. African locust bean fruit pulp was rich in fiber and Vitamin C, with a high β-carotene value. The cashew kernel had the highest energy value. Regarding mineral composition, African locust bean fruit pulp had the highest potassium content, while Bambara groundnut and African locust bean fruit pulp were rich in sodium. Cashew kernel and Fonio had higher iron and calcium content. Bambara groundnut had a higher zinc content, while cashew kernel had a higher magnesium content. The formulated flours made from fermented Fonio grains and enriched with Bambara groundnut, African locust bean fruit pulp, and cashew kernel had varying protein, fiber, carbohydrate, ash, and fat contents. The flour formulated with sprouted Fonio and enriched with the same ingredients had higher protein content and energy value than the other fermented seed-based flours. The mixed flours produced with fermented seeds and the flour produced from sprouted seeds met international standards. Overall, these findings offer valuable insights into the nutritional composition of the formulated flours and their potential to combat infant malnutrition in Côte d’Ivoire.

Reducing Effect of Parkia biglobosa (Jacq.) R. Br. ex G. Don Fruit Pulp on Food Intake in Healthy NMRI Mice

Obesity is a chronic condition characterised by excess body fat that leads to increased body weight. One of the most effective ways to treat obesity is to use appetite suppressants to reduce food intake. This study aimed to evaluate in vivo reduction of food intake and weight gain caused by Parkia biglobosa (Pb) fruit pulp. Twenty-four healthy NMRI mice divided into four groups were used for the experiment. Group 1, considered the negative control, received distilled water. Groups 2, 3, and 4 were administered daily with 100, 250 and 500 mg/kg body weight of Pb fruit pulp powder suspension, respectively. The reduction in food intake was assessed in two phases: acute food intake for one day (24 h) and long-term food intake for seven weeks. Nutrient parameters and phenolic compounds in Pb fruit pulp were quantified. The results showed that Pb fruit pulp had a significant effect on reducing acute food intake. At a dose of 250 mg/kg, Pb had the best activity in reducing acute food intake, with an overall reduction rate of approximately 47.98% ± 1.17% compared to the control. Repeated daily administration inhibited food intake with all three doses for 13 days compared to control. Food intake was significantly decreased for up to 31 days by taking a 100 mg/kg dose of Pb (p = 0.0174). Weight gain was significantly lower (p = 0.0003) in mice treated with 100 mg/kg Pb than in controls at the end of 7 weeks. According to the nutritional composition study, Pb fruit pulp contains an abundance of total carbohydrates (68.81% ± 0.32%) and crude fiber (14.35% ± 0.21%). This study demonstrated that Pb fruit pulp effectively reduces food intake in healthy mice. Pb pulp’s richness in crude fiber and phenolic compounds makes it a potential aid in managing obesity.

Hepatocyte growth factor enhances the ability of dental pulp stem cells to ameliorate atherosclerosis in apolipoprotein E-knockout mice

BACKGROUND Atherosclerosis(AS),a chronic inflammatory disease of blood vessels,is a major contributor to cardiovascular disease.Dental pulp stem cells(DPSCs)are capable of exerting immunomodulatory and anti-inflammatory effects by secreting cytokines and exosomes and are widely used to treat autoimmune and inflam-mation-related diseases.Hepatocyte growth factor(HGF)is a pleiotropic cytokine that plays a key role in many inflammatory and autoimmune diseases.AIM To modify DPSCs with HGF(DPSC-HGF)and evaluate the therapeutic effect of DPSC-HGF on AS using an apolipoprotein E-knockout(ApoE-/-)mouse model and an in vitro cellular model.METHODS ApoE-/-mice were fed with a high-fat diet(HFD)for 12 wk and injected with DPSC-HGF or Ad-Null modified DPSCs(DPSC-Null)through tail vein at weeks 4,7,and 11,respectively,and the therapeutic efficacy and mechanisms were analyzed by histopathology,flow cytometry,lipid and glucose measurements,real-time reverse transcription polymerase chain reaction(RT-PCR),and enzyme-linked immunosorbent assay at the different time points of the experiment.An in vitro inflammatory cell model was established by using RAW264.7 cells and human aortic endothelial cells(HAOECs),and indirect co-cultured with supernatant of DPSC-Null(DPSC-Null-CM)or DPSC-HGF-CM,and the effect and mechanisms were analyzed by flow cytometry,RT-PCR and western blot.Nuclear factor-κB(NF-κB)activators and inhibitors were also used to validate the related signaling pathways.RESULTS DPSC-Null and DPSC-HGF treatments decreased the area of atherosclerotic plaques and reduced the expression of inflammatory factors,and the percentage of macrophages in the aorta,and DPSC-HGF treatment had more pronounced effects.DPSCs treatment had no effect on serum lipoprotein levels.The FACS results showed that DPSCs treatment reduced the percentages of monocytes,neutrophils,and M1 macrophages in the peripheral blood and spleen.DPSC-Null-CM and DPSC-HGF-CM reduced adhesion molecule expression in tumor necrosis factor-αstimulated HAOECs and regulated M1 polarization and inflammatory factor expression in lipopolysaccharide-induced RAW264.7 cells by inhibiting the NF-κB signaling pathway.CONCLUSION This study suggested that DPSC-HGF could more effectively ameliorate AS in ApoE-/-mice on a HFD,and could be of greater value in stem cell-based treatments for AS.

Human dental pulp stem/stromal cells in clinical practice

Dental pulp stem/stromal cells(DPSCs)are fibroblast-like,neural crest-derived,and multipotent cells that can differentiate into several lineages.They are relatively easy to isolate from healthy and inflamed pulps,with little ethical concerns and can be successfully cryopreserved and thawed.The therapeutic effects of DPSCs derived from animal or human sources have been extensively studied through in-vitro and in-vivo animal experiments and the findings indicated that DPSCs are effective not only for dental diseases but also for systemic diseases.Understanding that translational research is a critical step through which the fundamental scientific discoveries could be translated into applicable diagnostics and therapeutics that directly benefit humans,several clinical studies were carried out to generate evidence for the efficacy and safety of autogenous or allogeneic human DPSCs(hDPSCs)as a treatment modality for use in cell-based therapy,regenerative medicine/dentistry and tissue engineering.In clinical medicine,hDPSCs were effective for treating acute ischemic stroke and human exfoliated deciduous teeth-conditioned medium(SHED-CM)repaired vascular damage of the corpus cavernous,which is the main cause of erectile dysfunction.Whereas in clinical dentistry,autologous SHED was able to rege-nerate necrotic dental pulp after implantation into injured teeth,and micrografts enriched with autologous hDPSCs and collagen sponge were considered a treatment option for human intrabony defects.In contrast,hDPSCs did not add a significant regenerative effect when they were used for the treatment of post-extraction sockets.Large-scale clinical studies across diverse populations are still lacking to provide robust evidence on the safety and efficacy of hDPSCs as a new treatment option for various human diseases including dental-related problems.

三氧化矿物凝聚体与氢氧化钙盖髓在成人不可复性牙髓炎活髓切断术中的应用效果比较

目的:比较三氧化矿物凝聚体与氢氧化钙盖髓在成人不可复性牙髓炎活髓切断术中的应用效果。方法:回顾性分析2020年12月至2023年12月该院收治的80例不可复性牙髓炎患者的临床资料,按照盖髓材料不同将其分为研究组和对照组各40例。两组均行活髓切断术治疗,对照组术中采用氢氧化钙盖髓,观察组术中采用三氧化矿物凝聚体盖髓。比较两组手术成功率,手术前后疼痛[视觉模拟评分法(VAS)]评分、龈沟液炎性因子[肿瘤坏死因子-α(TNF-α)、超敏C反应蛋白(hs-CRP)、白细胞介素-6(IL-6)]水平,以及并发症发生率。结果:观察组手术成功率为97.50%(39/40),高于对照组的75.00%(30/40),差异有统计学意义(P<0.05);术后3个月,两组VAS评分均低于术前,且观察组低于对照组,差异有统计学意义(P<0.05);术后3个月,两组龈沟液TNF-α、hs-CRP、IL-6水平均低于术前,且观察组低于对照组,差异有统计学意义(P<0.05);观察组并发症发生率为2.50%(1/40),低于对照组的22.50%(9/40),差异有统计学意义(P<0.05)。结论:三氧化矿物凝聚体盖髓应用于成人不可复性牙髓炎活髓切断术中可提高手术成功率,降低疼痛评分、龈沟液炎性因子水平和并发症发生率,效果优于氢氧化钙盖髓。

游离趾腓侧瓣与指背岛状皮瓣在手指末节指腹缺损修复中的应用对比

目的对比游离趾腓侧瓣与指背岛状皮瓣在手指末节指腹缺损修复中的应用效果。方法选取2022年1月至2024年1月在安阳市人民医院进行游离趾腓侧瓣与指背岛状皮瓣在手指末节指腹缺损修复的80例患者作为研究对象,其中40例患者采用游离趾腓侧瓣进行修复的患者纳入观察组;另选取40例采用指背岛状皮瓣进行修复的患者纳入对照组。比较两组术后患指较健侧短缩水平、皮瓣两点辨别觉、手功能恢复优良率、皮瓣外观感觉评分、皮瓣成活率。结果观察组患者患指较健侧短缩水平小于对照组,差异有统计学意义(P<0.05)。观察组患者在术后1个月、2个月、3个月后皮瓣两点辨别觉大于对照组,差异有统计学意义(P<0.05)。观察组术后6个月的手功能恢复优良率为85.00%,对照组术后6个月的手功能恢复优良率为82.50%,对比差异无统计学意义(P>0.05)。观察组患者的皮瓣外观感觉评分高于对照组,差异有统计学意义(P<0.05)。观察组术后皮瓣成活率为90.00%,对照组术后皮瓣成活率为72.50%,观察组高于对照组,差异有统计学意义(P<0.05)。结论在手指末节指腹缺损修复中,采用游离趾腓侧瓣具有患指较健侧短缩水平小、皮瓣外观感觉好、皮瓣成活率高的优点,但采用背岛状皮瓣在皮瓣两点辨别觉优于游离趾腓侧瓣,两种方式均有良好的手功能恢复优良率。

Preparation and application of cationized pulp fiber as a papermaking wet-end additive

Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF preparation were： 4% of 31441 （based on oven-dry pulp）, 80℃ and 30 rain. The CPF was characterized by FT-IR, SEM and XPS. Experimental results showed that the CPF improved the retention of precipitated calcium carbonate （PCC） filler significantly. With 0.9% CPF （based on oven-dry pulp）, the retention of PCC increased from 57.53% to 72.21%. The physical properties of paper were also slightly improved. The tensile strength and burst strength of the paper with CPF were higher than those with CPAM. CPF addition had no effect on the stock drainage.

11份可可种质果实性状及品质综合评价

为筛选果实性状、果肉和可可豆品质均优异的可可育种材料,对11份可可种质的果实质量、果壳质量、果长、果宽、种子鲜质量、果肉含量、可溶性糖、总酸、pH、糖酸比、果肉感官评价(香气、酸甜感、接受度)、可可脂、可可碱、咖啡因和多酚17个指标进行测定,并通过主成分分析和聚类分析对不同可可种质果实的17个指标进行综合评价。结果表明:17个指标的变异系数为4.16%~52.91%,平均为16.73%,其中咖啡因的变异系数最大。果肉含量、总酸、糖酸比、咖啡因的变异系数均在20%以上,11份可可种质在果实性状和品质上均存在较大差异,具有丰富的遗传多样性。对可可果肉的感官评价中,香可16号的测评分数最高,其次是TAS420、TAS1413;此外,测评者的接受度主要与果肉的酸甜有关。相关性分析表明,果实性状与果肉品质间主要呈正相关关系,而可可豆品质性状与它们主要呈负相关关系。主成分分析中,共提取出5个特征值大于1的主成分,累计贡献率为89.521%;基于各指标的主成分得分进行综合排名,TAS420、香可16号、TAS414的综合评分最高,在果实性状、果肉和可可豆品质上表现均优异。主成分1和主成分2在综合评价中起到关键作用,其中pH、糖酸比、感官评价、果实质量、果壳质量、果宽的指标对可可果实的贡献率较大。依据聚类分析,将11份可可种质细分为4个类群,第一类群仅有TAS1413,其果实性状和果肉品质均较为优异,但可可豆品质最差;第二、第三类群为综合排名前四的种质,综合指标较为优异,是培育优良品种的重要材料。剩下的6份种质为第四类群,其果实性状和品质较为一般。本研究为可可优良品种培育提供基础,有助于可可产业的多元化发展。

光交联复合水凝胶支架中人牙髓干细胞的成骨/成牙分化能力

背景:甲基丙烯酸酐改性明胶(gelatin-methacryloyl,Gel-MA)与经处理牙本质基质(treated dentin matrix,TDM)在一定比例下经过紫外线交联后形成的复合水凝胶支架具有良好的孔隙率、机械性能、溶胀性能及生物降解率,这为临床上年轻恒牙的牙髓再生提供了新的思路和方法。目的:探究1∶2质量比Gel-MA/TDM复合光交联水凝胶支架对人牙髓干细胞增殖能力及成骨/成牙本质分化能力的影响。方法:将第3代牙髓干细胞接种至1∶2质量比Gel-MA/TDM复合水凝胶支架中,采用CCK-8实验检测人牙髓干细胞在复合水凝胶支架中的增殖能力。将第3代牙髓干细胞接种至1∶2质量比Gel-MA/TDM复合水凝胶支架中并进行成骨诱导,采用碱性磷酸酶染色及茜素红染色观察矿化结节的形成情况,采用RT-PCR检测成牙相关因子(牙本质基质蛋白1、牙本质涎磷蛋白)和成骨相关因子(骨钙素、Runt相关转录因子2)的基因表达。结果与结论:①CCK-8检测结果显示,前7 d的牙髓干细胞增殖能力明显升高,第10天时速度减缓;②碱性磷酸酶染色及茜素红染色结果显示,Gel-MA/TDM复合水凝胶组牙髓干细胞的碱性磷酸酶活性及矿化结节生成强于单纯Gel-MA水凝胶组(P<0.05);③RT-PCR结果显示,Gel-MA/TDM复合水凝胶组牙髓干细胞中牙本质基质蛋白1、牙本质涎磷蛋白、骨钙素、Runt相关转录因子2的基因表达量明显高于单纯Gel-MA水凝胶组(P<0.05),且14 d基因表达量明显高于7 d(P<0.05)。结果表明,培养在1∶2 Gel-MA/TDM复合水凝胶支架上的牙髓干细胞表现出较好的增殖能力,能够强化牙髓干细胞的成骨、成牙本质分化能力。

类木质素母体小分子对甲酸蒸煮纸浆性能的影响

本研究构建了类木质素母体小分子协同甲酸的蒸煮体系,在蒸煮过程中,利用类木质素母体小分子与木质素碳正离子的亲核反应,抑制木质素分子间的缩合,从而提高木质素去除率,探究类木质素母体小分子对纸浆白度和纸张强度性能的影响。结果表明,甲酸分别与对羟基苯甲醛、对羟基苯甲酸、香草醛、愈创木酚、紫丁香醇、水杨酸和苯甲醛组成蒸煮体系对杨木和松木进行组分分离,所得杨木浆白度(70.2%)高于松木浆(57.6%)。相比单一甲酸蒸煮体系,添加愈创木酚和紫丁香醇后获得的杨木浆白度由41.5%分别提升至70.2%和69.4%;同时,杨木浆中纤维素含量高于90%,木质素含量低于2%,制备纸张的撕裂、耐破和抗张指数显著提升,分别达3.16 mN·m^(2)/g、1.03 kPa·m^(2)/g和31.5 N·m/g。

Pulpdent Multi-Cal用于年轻恒前牙活髓切断术的临床研究

目的:研究Pulpdent Multi-Cal(PMC)盖髓剂用于活髓切断术的临床可操作性和疗效,为临床应用提供参考依据。方法:对因冠折露髓到北京大学口腔医院急诊科就诊患者的上颌年轻恒前牙25颗(20例患者)进行活髓切断术,用PMC盖髓剂作为活髓保存剂,观察临床可操作性和操作时间,术后对患牙进行定期随访观察,复诊时记录患牙的临床检查和X线片检查情况,并与采用北京大学口腔医院自制制剂进行活髓切断术的患牙进行比较。结果:随访6～15个月(中位时间12个月),25颗患牙(20例患者)均于1～3个月间在X线片上观察到钙化桥的形成并持续增厚,牙根继续发育,无根内外吸收和根管钙化出现。应用PMC盖髓剂活髓切断术中操作时间显著缩短(P<0.01),术后牙根长度的发育与正常的中切牙差异无统计学意义(P>0.05)。结论:使用PMC盖髓剂进行活髓切断术取得了较满意的疗效,可以作为一种成品制剂应用于临床活髓切断术的常规治疗,有助于缩短临床操作时间、控制感染,也可为研究年轻恒牙活髓保存技术和新型盖髓剂提供统一的参照标准。

负载骨形态发生蛋白2水凝胶诱导牙髓干细胞的成骨分化

背景:前期研究证明,甲基丙烯酸酐改性明胶/经处理牙本质基质复合水凝胶支架可促进人牙髓干细胞的增殖及分化。水凝胶负载骨形态发生蛋白2被认为是骨修复中有前景的材料。目的:观察负载不同质量浓度骨形态发生蛋白2的甲基丙烯酸酐改性明胶/经处理牙本质基质复合水凝胶对人牙髓干细胞成骨向分化的诱导作用。方法:制备含0,50,100,200μg/mL骨形态发生蛋白2的甲基丙烯酸酐改性明胶/经处理牙本质基质复合水凝胶,分别记为GelMA/TDM、BMP-2(50 ng/mL)GelMA/TDM、BMP-2(100 ng/mL)GelMA/TDM、BMP-2(200 ng/mL)GelMA/TDM,检测复合水凝胶对骨形态发生蛋白2的体外缓释性能。采用改良组织块酶消化法提取人牙髓干细胞,分别接种于4种水凝胶表面,采用CCK-8法检测细胞增殖,DAPI染色检测细胞黏附;对各组水凝胶表面的人牙髓干细胞进行成骨诱导,进行碱性磷酸酶染色、碱性磷酸酶活性检测与茜素红染色,采用RT-PCR法检测相关成骨基因(Runx2、骨形态发生蛋白2、骨桥蛋白、骨钙素、Ⅰ型胶原)表达。结果与结论:①甲基丙烯酸酐改性明胶/经处理牙本质基质复合水凝胶可持续释放骨形态发生蛋白2长达21 d,在第3-6天释放较快,第6天之后释放趋于平稳;②4种水凝胶均可促进人牙髓干细胞的增殖,其中以BMP-2(100 ng/mL)-GelMA/TDM复合水凝胶的作用最明显;相较于GelMA/TDM复合水凝胶,BMP-2-GelMA/TDM复合水凝胶可促进人牙髓干细胞的黏附,其中以BMP-2(200 ng/mL)-GelMA/TDM复合水凝胶的作用最明显;③相较于GelMA/TDM复合水凝胶,BMP-2-GelMA/TDM复合水凝胶可提升碱性磷酸酶活性、钙结节含量与相关成骨基因表达,综合分析显示BMP-2(100 ng/mL)-GelMA/TDM复合水凝胶的作用更明显;④结果表明,BMP-2(100 ng/mL)-GelMA/TDM复合水凝胶促进牙髓干细胞成骨向分化的能力更明显。

对比不同生物支架用于年轻恒牙牙髓血运重建效果的贝叶斯网状Meta分析

目的:临床中用于牙髓血运重建的生物支架多种多样,不同支架材料之间的疗效差异存在争议。采用贝叶斯网状Meta分析方法评价9种生物支架在牙髓血运重建术中的效果。方法:检索中国知网、维普、万方、中国生物医学文献服务系统、PubMed、Cochrane Library、Web of Science、Embase、Scopus数据库,收集各数据库建库至2024-04-01符合纳入标准的关于不同生物支架用于年轻恒牙牙髓血运重建治疗的随机对照试验。由2位研究者筛选文献,独立完成数据的收集和整理提取,并对纳入的文献质量进行偏倚风险评价,使用R 4.2.0软件的BUGSnet 1.1.1包进行网状Meta分析。结果:共纳入22篇研究,包含926例患牙数和9种不同的干预措施,网状Meta分析结果显示:①临床成功率(一级目标):富血小板纤维蛋白优于血凝块[OR=1.45,95%CI(0.32,2.69)],等级概率排序结果前3为:浓缩生长因子(82.77%)>富血小板纤维蛋白(75.38%)>改良富血小板纤维蛋白(62.39%);②牙根长度增加(二级目标):随访1-6个月时,7种生物支架之间比较无差异(P>0.05),等级概率排序结果前3为:浓缩生长因子(86.25%)>富血小板血浆(53.76%)>富血小板纤维蛋白(51.11%);随访>6个月且≤12个月时,浓缩生长因子优于血凝块[MD=9.59,95%CI(0.52,18.40)],等级概率排序结果前3为:浓缩生长因子(92.42%)>富血小板血浆(56.03%)>富血小板纤维蛋白(55.76%);随访大于12个月时,浓缩生长因子优于改良富血小板纤维蛋白[MD=11.01,95%CI(0.02,22.72)],等级概率排序结果前3为:浓缩生长因子(86.95%)>富血小板纤维蛋白(68.61%)>血凝块联合胶原蛋白(52.5%);③根壁厚度增加(二级目标):随访1-6个月时,富血小板纤维蛋白优于血凝块[MD=11.37,95%CI(4.74,17.71)],等级概率排序结果前3为:富血小板纤维蛋白(93.66%)>浓缩生长因子(63.11%)>改良富血小板纤维蛋白(50.48%);随访>6个月且≤12个月时,6种生物支架之间比较无差异(P>0.05),等级概率排序结果前3为:改良富血小板纤维蛋白(73.63%)>富血小板纤维蛋白(62.36%)>浓缩生长因子(56.25%);随访大于12个月时,9种生物支架之间比较无差异(P>0.05),等级概率排序结果前3为:血凝块联合胶原蛋白(81.9%)>富血小板血浆(62.67%)>改良富血小板纤维蛋白(59.49%);④牙髓活力(三级目标):6种生物支架之间比较无差异(P>0.05),等级概率排序结果前3为:血凝块联合胶原蛋白(84.22%)>浓缩生长因子(67.71%)>富血小板纤维蛋白(48.79%)。结论:现有证据表明,不同支架在牙髓血运重建术中的临床成功率均较高,其中富血小板纤维蛋白优于血凝块;牙根长度和根壁厚度增加综合比较方面,浓缩生长因子在随访1-6个月与>6个月且≤12个月时间段中表现最佳,而随访大于12个月后血凝块联合胶原蛋白表现最佳;浓缩生长因子在各级目标中表现突出,相对其他支架可能更有利于牙根的继续发育,在牙髓再生治疗中有巨大潜力。受限于文献质量及数量,上述结论仍需更多高质量研究予以验证。