骨髓基质干细胞在中空多孔金属试件内诱导成骨的研究

目的:观察体外培养犬骨髓基质干细胞(BMSCs)在中空多孔金属试件与脱钙骨基质内、外的分化生长情况以及成骨的可能性.方法:按中空多孔金属试件的中空部分是否填充DBM,以及所选择成骨诱导培养液和rhBMP-2培养液的不同进行分组,共四组,每组四枚.体外培养BMSCs,诱导分化,借助相差显微镜、免疫染色、扫描电镜观察中空多孔金属试件内BMSCs的分化、增殖及成骨情况,并隔天测定各组的骨特异性ALP浓度.结果:体外BMSCs经诱导向成骨细胞分化,并可在中空多孔金属试件内的空间结构中形成组织块.以骨特异性ALP为指标比较成骨诱导培养液和rhBMP-2培养液的诱导成骨功效,证明成骨诱导液更为明显,但两者无显著差异(P＞0.05).结论:中空多孔金属试件中BMSCs可经诱导成骨.     

微弧氧化后锆铜铝银非晶合金的细胞相容性研究

目的:探讨微弧氧化(micro-arc oxidation,MAO)后的Zr46(Cu4.5/5.5Ag1/5.5)46Al8(at%)(本文简称Zr-Cu-Al-Ag非晶合金)的细胞相容性。方法:按照国家标准制备300 V、350 V和400 V电压MAO处理的Zr-Cu-Al-Ag非晶合金、铸态Zr-Cu-Al-Ag非晶合金以及TI6Al4V合金试件的浸提液用于培养L929细胞,阴性组的L929细胞用含10%小牛血清的DMEM溶液培养,阳性组的L929细胞用含64 g/L苯酚和10%小牛血清的DMEM溶液培养,通过四唑盐(MTT)比色法分析试件的细胞相容性。结果:MAO处理的Zr-Cu-Al-Ag非晶合金细胞毒性评级为0,其浸提液中的L929细胞状态良好,细胞增殖曲线呈上升趋势,三个MAO组的吸光度值高于铸态Zr-Cu-Al-Ag非晶合金组、TI6Al4V合金组和阳性对照组(P0.05),但与阴性对照组无明显差别(P0.05)。结论:MAO提高了Zr-Cu-Al-Ag非晶合金表面的细胞相容性。     

人脐静脉内皮细胞在D,L-聚乳酸基形状记忆聚合物上的黏附和增殖行为研究

生物可降解的形状记忆聚合物兼具生物可降解性和形状记忆特性,作为医疗器械植入人体,在完成功能后能够在体液的作用下发生降解,对人体无毒无害,避免了二次手术对病人造成的痛苦以及避免医疗器械长期植入体内存在带来的安全隐患。作为医疗器械植入体,需要具有良好的细胞相容性。实验将D,L-聚乳酸基形状记忆聚合物与人脐静脉内皮细胞在体外复合培养,以考察细胞在材料上的增殖能力。实验中观察了细胞形态(HE染色观察),采用了铺膜法和浸提液法评价了细胞的增殖能力。结果表明：与对照组聚乳酸相比,铺膜法和浸提液法评价细胞的增殖能力所得结论具有一致性,形状记忆材料在细胞黏附和增殖表现良好。     

新一代医用刚质聚合物外科植入动物实验研究

目的:研究新一代医用刚质聚合物的植入动物后的变化情况,方法:根据美国材料协会(ASTM)标准中有关用于外科植入的聚合物材料相容性评价实施标准,对新一代医用刚质聚合物进行外科植入动物试验。结果:试验样品和对照样品周围组织出现的变化同步。结果:新一代刚质聚合物与已在临床上应用的聚合物具有相同的生物相容性。同样可作为人工材料应用于临床。     

籼型水稻原生质体再生植株

以在MSB培养基(MS无机盐,B 5有机成份附加2mg／L 2．4－D)中继代一年的87－l籼型花粉愈伤组织和由籼型水稻株系81－3在改良的RY一2培养基中继代半年的悬浮培养物游离原生质体,分别在RY 2和KPR培养基中进行液体浅层培养或琼脂糖包埋培养,并在琼脂糖包埋培养时饲喂以粳型广亲和材料02428的悬浮培养细胞或除去}王胞的调渗悬浮液。原生质体植板率达8．7％－12．5％。将3—4周后形成的肉眼可见的小愈伤组织转移到台o．5mg／L 2．4－D的N6固体培养基上增殖,待愈伤组织长到直径达2—3mm大小时,分别或串换使用三种不同激素水平的分化培养基,最终由籼型株系81－3的原生质体再生了植株,而87－1籼型花粉胚性愈伤组织原生质体只再生了愈伤组织。     

疣粒野生稻胚性悬浮细胞系的建立及其原生质体的培养和植株再生

云南疣粒野生稻的成熟种子经55℃温度处理3d打破休眠后,在诱导培养基上诱导出愈伤组织。挑选胚性愈伤组织置于液体培养基中振荡培养,经3个月的继代培养,建立胚性细胞悬浮系。悬浮细胞经酶解、去壁后获得大量原生质体,固体包埋后添加液体培养基进行原生质体培养。在培养过程中调节培养体系的渗透压,获得小愈伤组织;经增殖后在分化培养基上诱导产生胚状体,成功得到疣粒野生稻的原生质体再生植株。     

苏云金杆菌内毒素蛋白基因转入葡萄胚性愈伤组织细胞及转基因植株再生的研究

以葡萄的胚性愈伤组织作为农杆菌介导,Ti质粒转化材料,利用共培养法将苏云金杆菌内毒素蛋白基因转入葡萄胚性愈伤组织细胞,通过胚状体发生途径再生转基因植株。实验发现:80μmol/L的乙酰丁香酮诱导处理农杆菌和葡萄愈伤组织后可将转化效率提高50倍。OD值为0.8的农杆菌菌液稀释8—10信后与在G培养基预培养10天的胚性愈伤组织共培养2—3夭,Ti质粒对葡萄愈伤组织细胞的转化效率可达50%左右。筛选得到的转基因植株在含Km 30 mg/L的选择培养基上继代存活6个月,生长正常;提取叶片染色体DNA做Southern blot,杂交结果为阳性。将转基因植株各部分切段置于含Km 50 mg/L的选择培养基上,能够脱分化产生抗性愈伤组织并能增殖。     

许旺细胞复合改性PLA\PGA的体外生物学研究

目的：评价小鼠许旺细胞体外复合改性聚乳酸\聚羟基乙酸（PLA\PGA）的细胞活性及生物相容性。方法：转绿色荧光蛋白基 因（GFP）小鼠的许旺细胞传代培养至第2 代,然后通过MTT 检测在不同改性技术（H2O2、NaOH、NaClO4、K2CrO4及超声波）处理 的PLA\PGA 浸提液中许旺细胞的增殖情况,检测许旺细胞在PLA\PGA表面的黏附及其细胞形态。结果：于培养1 d,3 d测得在 不同改性技术处理的PLA\PGA浸提液OD值,1 天时,各浸提液组和对照组相比无显著性差异,许旺细胞的活力及增殖无影响。3 天时,经NaClO4及K2CrO4处理的PLA\PGA 与对照组相比具有统计学差异,影响许旺细胞的增殖,对许旺细胞有毒性;荧光显微 镜下观察到许旺细胞在改性PLA\PGA 表面逐渐伸展,形成伪足,最终粘附在材料表面。结论：经H2O2、NaOH 及超声波改性 PLA\PGA无细胞毒性,具有良好的生物相容性和黏附性,可以用于组织工程化神经的构筑。     

全身纤维结缔组织网络中的界面流体传输现象

纤维结缔组织在身体中的作用是支撑、连接和分隔不同的组织和器官。最近,人体断肢解剖研究证实,一种定向纤维结缔组织组成了一种长程液体传输通路。其解剖位置有两种:皮肤传输通路(包括真皮、皮下组织和脂肪小叶间隔)和血管周围传输通路(静脉和动脉周围纤维结缔组织)。这种纤维通路的三维空间内部结构是一种纵向分布、相互连接的纤维丝,在每一根纤维丝及其周围水凝胶之间形成了一种固液界面区;纤维结缔组织中的液体能够通过这种界面区传输,命名为"生物界面流体传输通路";存在于各种组织和器官纤维基质中的液体,很可能并没有被束缚在"组织凝胶"中,而是在尚未明确的某种物理机制的作用下,朝向一定的方向传输。这些研究结果为理解纤维结缔组织的功能提供了一个新的视角。     

深低温冻存组织工程化软骨在喉狭窄功能重建中的应用

目的：探讨低温保存组织工程化软骨在喉狭窄功能重建中的应用价值。方法：取3周龄新西兰兔关节软骨细胞,体外培养,取第2代对数生长期培养细胞,制成细胞悬液,调整软骨细胞悬液浓度约为5×10^7个／ml左右,接种于PGA三维支架材料上,复合物体外培养2周后冻存,冻存6个月后解冻复苏,再行体外培养观察,2周后接种于已建立的喉甲状软骨缺损模型的软骨缺损处,并设对照组。术后12周取材,行大体及组织学观察。结果：经低温冻存的组织工程化软骨生长良好,组织学观察有软骨形成,与周围软骨组织结合紧密,与非冻存组相比差异无统计学意义。结论：深低温冻存对组织工程化软骨的生物活性无明显的影响,低温冻存的组织工程化软骨可用于喉软骨缺损的修复,重建喉功能。     

A finite element model of the L4-L5 spinal motion segment: biomechanical compatibility of an interspinous device

The biomechanical compatibility of an interspinous device, used for the "dynamic stabilization" of a diseased spinal motion segment, was investigated. The behaviour of an implant made of titanium based alloy (Ti6Al4V) and that of an implant made of a super-elastic alloy (Ni-Ti) have been compared. The assessment of the biomechanical compatibility was achieved by means of the finite element method, in which suitable constitutive laws have been adopted for the annulus fibrosus and for the metal alloys. The model was aimed at simulating the healthy, the nucleotomized and the treated L4-L5 lumbar segment, subjected to compressive force and flexion-extension as well as lateral flexion moments. The computational model has shown that both the implants were able to achieve their main design purpose, which is to diminish the forces acting on the apophyseal joints. Nevertheless, the Ni-Ti implant has shown a more physiological flexural stiffness with respect to the Ti6Al4V implant, which exhibited an excessive stiffness and permanent strains (plastic strains), even under physiological loads. The computational models presented in this paper seems to be a promising tool able to predict the effectiveness of a biomedical device and to select the materials to be used for the implant manufacturing, within an engineering approach to the clinical problem of the spinal diseases.     

镍钛形状记忆合金环抱器内固定术对多发性肋骨骨折患者术后疼痛、呼吸功能及肺部感染的影响

目的:探讨多发性肋骨骨折患者采用镍钛形状记忆合金环抱器内固定术治疗的临床效果。方法:选取2016年1月-2018年1月期间我院收治的97例多发性肋骨骨折患者。按照不同的治疗方法将患者分为对照组(n=47)和研究组(n=50),对照组患者给予胸部护板外固定术,研究组患者给予镍钛形状记忆合金环抱器内固定术。比较两组患者术后7 d的临床疗效,比较两组术前、术后7 d疼痛程度及呼吸功能情况,记录两组术后并发症发生情况。结果:研究组患者治疗后总有效率为92.00%(46/50),高于对照组患者的76.60%(36/47)(P0.05)。两组患者术后7 d视觉疼痛模拟评分量表(VAS)评分均较术前降低,且研究组低于对照组(P0.05)。两组患者术后7 d最大自主通气量占预计值百分比(MVV%)较术前升高,且研究组高于对照组(P0.05);两组患者术后7 d第1秒用力呼气肺活量占预计值百分比(FEV1%)比较无差异(P0.05)。研究组患者术后并发症总发生率8.00%(4/50),低于对照组的23.40%(11/47)(P0.05)。结论:多发性肋骨骨折经镍钛形状记忆合金环抱器内固定术治疗安全、有效,可明显减轻患者术后疼痛及改善呼吸功能,临床应用价值较高。     

随机、平行对照评价陶瓷膜室间隔缺损封堵器安全性和有效性

目的:随机、平行对照的临床试验验证先健科技(深圳)有限公司生产的TM陶瓷膜VSD封堵器治疗室间隔缺损的安全性及有效性。方法:根据试验的要求入选术前确诊为室间隔缺损的病人42例,随机分为实验组(A组)和对照组(B组),每组各21例,对A组病人植入CeraTM陶瓷膜VSD封堵器,对B组病人植入普通镍钛合金VSD封堵器,在超声心动图下或X线下观察室间隔缺损大小、位置、形态、类型,选择合适的封堵伞,经输送系统置入封堵器闭合VSD,分别于术前、术后24小时、术后30天、90天及术后180天进行随访,主要随访内容包括临床症状和体征、超声心动图、心电图、胸片、24小时动态心电图检查等。比较这两组患者的即刻手术成功率以及随访过程中终点事件发生率的不同。结果:试验组和对照组的成功率均为100%,残余分流率分别为0和4.8%,试验组的并发症发生率与对照组未见明显差异(P0.005)。结论:试验组与对照组安全性与疗效相当,应用国产陶瓷封堵器是安全、有效的。但由于该项技术是一项新技术,临床试验样本量较少,其安全性和疗效特别是中远期疗效仍需进一步观察。     

Computational studies of shape memory alloy behavior in biomedical applications

BACKGROUND: Nowadays, shape memory alloys (SMAs) and in particular Ni-Ti alloys are commonly used in bioengineering applications as they join important qualities as resistance to corrosion, biocompatibility, fatigue resistance, MR compatibility, kink resistance with two unique thermo-mechanical behaviors: the shape memory effect and the pseudoelastic effect. They allow Ni-Ti devices to undergo large mechanically induced deformations and then to recover the original shape by thermal loading or simply by mechanical unloading. METHOD OF APPROACH: A numerical model is developed to catch the most significant SMA macroscopic thermo-mechanical properties and is implemented into a commercial finite element code to simulate the behavior of biomedical devices. RESULTS: The comparison between experimental and numerical response of an intravascular coronary stent allows to verify the model suitability to describe pseudo-elasticity. The numerical study of a spinal vertebrae spacer where the effects of different geometries and material characteristic temperatures are investigated, allows to verify the model suitability to describe shape memory effect. CONCLUSION: the results presented show the importance of computational studies in designing and optimizing new biomedical devices.     

Effect of Tricalcium Magnesium Silicate Coating on the Electrochemical and Biological Behavior of Ti-6Al-4V Alloys

In the current study, a sol-gel-synthesized tricalcium magnesium silicate powder was coated on Ti-6Al-4V alloys using plasma spray method. Composition of feed powder was evaluated by X-ray diffraction technique before and after the coating process. Scanning electron microscopy and atomic force microscopy were used to study the morphology of coated substrates. The corrosion behaviors of bare and coated Ti-6Al-4V alloys were examined using potentiodynamic polarization test and electrochemical impedance spectroscopy in stimulated body fluids. Moreover, bare and coated Ti-6Al-4V alloys were characterized in vitro by culturing osteoblast and mesenchymal stem cells for several days. Results demonstrated a meaningful improvement in the corrosion resistance of Ti-6Al-4V alloys coated with tricalcium magnesium silicate compared with the bare counterparts, by showing a decrease in corrosion current density from 1.84 μA/cm² to 0.31 μA/cm². Furthermore, the coating substantially improved the bioactivity of Ti-6Al-4Valloys. Our study on corrosion behavior and biological response of Ti-6Al-4V alloy coated by tricalcium magnesium silicate proved that the coating has considerably enhanced safety and applicability of Ti-6Al-4V alloys, suggesting its potential use in permanent implants and artificial joints.     

Direct Epoxy Embedding for Vertical Sectioning of Cells Grown as a Monolayer on Millipore Filter

Cells cultured as a monolayer on MF-Millpore GSWP. 0.22 μ pore size, filter were fixed, dehydrated, and examined by phase-contrast microscopy with the filter immersed in a 1:1 mixture of xylene and the embedding medium. The membrane was cut into 2 × 20 mm strips, and each strip which was selected for desired cells was embedded vertically in a BEEM capsule. Thus direct embedding which allowed edgewise sectioning of cells was obtained without removing them from the culturing support.     

脂肪干细胞与放射后成纤维细胞共培养模型的建立和lncRNA高通量测序

目的:探讨大鼠脂肪来源干细胞(adipose-derived stem cells,ADSCs)对放射后成纤维细胞(fibroblast,Fb)的影响。方法:体外原代培养SD大鼠ADSCs和真皮Fb,分别对两种细胞进行鉴定,Fb辐照后两种細胞建立共培养模型。将Fb分为3组,对其进行lncRNA和mRNA转录本高通量测序。结果:ADSCs高表达CD29和CD44,低表达CD31和CD45。大鼠Fb高表达波形蛋白。Fb单纯辐照和干細胞干预后转录水平有明显的差异。结论:ADSCs能使辐射后的Fb細胞lncRNA和mRNA转录水平明显的改变,提示多项生物学功能及信号通路在其中发挥作用。     

Development of silver-containing austenite antibacterial stainless steels for biomedical applications part I: microstructure characteristics, mechanical properties and antibacterial mechanisms

The as-quenched (AQ) microstructure of the Ag-containing alloys was found to be essentially a mixture of austenite (γ) and Ag phases. The Ag phase precipitates had a face-centered-cubic structure and lattice parameter a = 4.09 ?. When the alloy contained Ag ≥0.2 wt%, the mechanical properties were slightly enhanced because of the precipitate strengthening by the Ag phase precipitates. Moreover, the Ag-containing alloys exhibited ductile fracture after tensile testing. The results of an antibacterial test revealed that the Ag phase precipitates play a key role in the antibacterial mechanism of Ag-containing alloys: Ag(+) ions released from the Ag phase precipitates can kill bacteria. It is suggested that as AISI 316L alloy has an Ag content ≥0.2 wt%, it will have excellent antibacterial properties against both Staphylococcus aureus and Escherichia coli, with an antibacterial rate of nearly 100%.     

The dependence of the emotional state of 8- to 9-year-old children on the conditions of play]

Dependence was studied of emotional state of children, aged 8-9, on the terms of computer play: without additional instruction (with a strategy typical of the child), at time deficiency and at demonstration of techniques of play without limitation in time. Prior to and during the play the following parameters were recorded: heart rate (HR); frequency of basis tone (Fb.t.) and evaluation of frequency of the first formant (n(0] of the vowel "a" in the word "da" pronounced by the child during the play in response to acoustic signal; reaction time (RT) to acoustic signal; parameters of playing activity and also spontaneous verbal expressions of children. Increase of emotional stress during the play at time deficiency was accompanied by the most expressed changes of HR, RT, Fb.t., worsening of playing activity and the increase of the number of negative emotional reactions. When playing without additional instruction, the children showed the best results of playing activity, accompanied by the least expressed changes of HR and Fb.t. in comparison with the background at the greatest expressiveness of the n(0) change, and predominantly positive emotional reactions. The analysis of the correlation of the motivational and informational characteristics of the studied playing activity allowed to make a conclusion about preferential connection of HR and Fb.t. with the motivational and n(0) with informational components of the playing activity.     

Aceto-Orcein and Feulgen Stains for Anatomy and Cytology of Trematodes

Dicrocoelium dendriticum and Fasciola hepatica were killed in the extended condition without anesthetization by dropping them into 40% acetic acid or into aceto-orcein. By using aceto-orcein (La Cour, 1941), killing, fixing and staining were accomplished simultaneously: staining time 24 hr or more. Whole mounts were made by dehydrating, clearing and mounting in Canada balsam, or testes or the upper part of the uterus could be removed for squash preparations after as long as 2 mo in the fixing and staining fluid. For Feulgen staining, living specimens were placed in 40% acetic acid for 10—15 min and then transferred to either Gilson's fluid, for sections, or to acetic-ethanol (1:3) for squashes. Hydrolysis was either by 10% perchloric acid at 25°C for 12 hr or in 12V HCl at 60° for 10 min. The time for Feulgen staining (De Tomasi, 1936) was 1.5-4.0 hr. Squashes were made from testes and uterus in the same manner as after aceto-orcein or sections obtained after embedding in paraffin.