新型纳米骨关节修复重建材料的生物活性及近期对机体钙磷代谢的影响

目的 研究新型骨关节修复重建材料纳米羟基磷灰石/聚酰胺66（n-HA/PA66）植入兔肌和骨内后材料表面的生物学变化及近期对兔机体钙磷代谢的影响,为临床应用提供参考资料.方法 参照GB/T16886.5-1997-ISO 10993-5：1992对医用植入材料的评价规定标准,将n-HA/PA66植入新西兰大白兔骶棘肌及股骨髁内,在术前1 d及术后4 d,1周,2周和4周等不同时相点抽血化验血清钙磷含量,并设置空白对照;术后1周,2周,3周,4周,8周取出植入材料,以扫描电镜（SEM）对材料表面及材料/受体骨的界面进行形貌分析;对植入骨内标本再进行组织学切片观察材料/受体骨界面新骨形成情况.所得数据以SPSS10.0软件包进行统计学分析.结果 n-HA/PA66植入兔体内4 d后血清磷含量较植入前显著增高（P＜0.05）;余各时相点材料植入组植入后、前两两比较及分别与假手术对照组两两比较,血清钙磷含量均无显著性差异（P＞0.05）;SEM检测显示n-HA/PA66植入体内能够在其表面形成新的磷灰石晶体,能与受体骨发生牢固键合.结论 n-HA/PA66在动物体内具有良好的生物活性;植入体内近期对兔血清钙磷代谢未发生明显影响.     

纳米羟基磷灰石／聚酰胺66骨填充材料修复肢体良性骨肿瘤术后骨缺损的疗效分析

目的初步评估和分析纳米羟基磷灰石／聚酰胺66（nano—hydroxyapatite polyamide66,n—HA／PA66）骨填充材料修复良性骨肿瘤术后骨缺损的临床效果和安全性,并初步确定其适应证。方法2007年11月至2009年4月,应用n-HA／PA66骨填充材料修复45例良性骨肿瘤术后骨缺损,男28例,女17例;年龄18～60岁,平均36岁;骨巨细胞瘤16例,骨囊肿8例,纤维结构不良8例,软骨母细胞瘤13例;股骨远端12例,股骨近端7例,胫骨近端15例,肱骨近端4例,跟骨2例,尺骨、桡骨、掌骨、指骨、距骨各1例;肿瘤刮除、灭活及人工骨植入25例,14例加用内固定,6例加用异体骨板和内固定。肿瘤范围为1．0cm×1．0cm×1．5cm～9．0cm×3．0cm×3．0cm,骨缺损范围为2．0cm×1．5cm×2．0cm～11．0cm×3．5cm×3．5cm。结果除5例失随访外,40例获得随访,随访时间3—17个月,平均7．2个月。伤口均I／甲愈合,无一例发生切口感染、非特异炎症反应和排斥反应;术前、术后的血常规和免疫检查均无明显异常;均无明显肝、肾功能损害。X线片和CT检查示：术后病灶区域填充良好,密度较松质骨稍低,材料与瘤壁边界清楚;术后1个月,病灶区密度逐渐升高,可见植骨周围与自体骨结合处模糊,开始有少量新生骨痂形成;术后3个月,病灶区密度明显升高,病灶区从颗粒植骨周围间隙开始向中心融合成片,更多新生骨痂影融合;术后6个月,病灶区密度明显升高,病灶区大量新生骨痂形成。临床骨愈合时间为术后2～6个月,平均2．8个月,愈合率为94．5％。结论n—HA／PA66骨填充材料的生物相容性良好,无明显排斥反应和非特异炎症反应,修复囊性良性骨肿瘤和瘤样病变效果良好。     

聚酰胺-氨纳米微粒介导5-氟尿嘧啶联合小RNA-21抑制乳腺癌细胞生长的研究

目的 观察聚酰胺-氨(PAMAM)纳米微粒介导5-氟尿嘧啶(5-Fu)联合小RNA-21抑制乳腺癌细胞MCF-7生长的效果.方法 透析法制备5-Fu/PAMAM,孵育法同载miR-21抑制剂;透射电镜观察形貌;紫外分光光度计检测载药率和包封率;流式细胞仪检测转染效率及细胞凋亡;噻唑蓝(MTT)比色法检测细胞增殖;Transwell检测细胞侵袭能力变化.结果 5-Fu/PAMAM形貌规整,包封率为(66.21±4.11)%,载药率为(31.77±0.73)%,转染效率为(60.54±6.97)%;联合治疗组肿瘤细胞生长缓慢,在观察截止期时生存率(55.85±3.71)%;联合治疗组细胞凋亡率(18.32±2.42)%,与对照组比较明显增多(F=58.326,P<0.01);联合治疗组视野内细胞数目仅为(18.96±3.14)个,侵袭能力显著降低(F=16.409,P<0.01).结论 PAMAM可以实现5-Fu和miR-21的同载,并有效抑制乳腺癌细胞的体外生长.     

聚酰胺1010／聚乙烯—马来酸酐接枝共聚物共混物力学和热学性能研究

为了表明马来酸酐接枝聚烯烃后对聚酰胺的相容作用，本文研究了聚酰胺１０１０（ＰＡ１０１０）／聚乙烯－马来酸酐接枝共聚物（ＰＥ－ｇ－ＭＡＨ）共混物在不同ＭＡＨ接枝量下的结晶性与力学性能。研究表明，ＭＡＨ的存在导致ＰＥ－ｇ－ＭＡＨ－ｃｏ－ＰＡ１０１０共聚物的形成，而该共聚物在标题共混物中起着相容剂的作用。共混物的结晶性能变化显示了共混组分间存在一定程度的混溶性。在一定的ＭＡＨ含量内，标题共混物具有协同效应。     

Mechanical and thermal properties of polyamide versus reinforced PMMA denture base materials

PURPOSE

This in vitro study intended to investigate the mechanical and thermal characteristics of Valplast, and of polymethyl methacrylate denture base resin in which different esthetic fibers (E-glass, nylon 6 or nylon 6.6) were added.

MATERIALS AND METHODS

Five groups were formed: control (PMMA), PMMA-E glass, PMMA-nylon 6, PMMA-nylon 6.6 and Valplast resin. For the transverse strength test the specimens were prepared in accordance with ANSI/ADA specification No.12, and for the impact test ASTM D-256 standard were used. With the intent to evaluate the properties of transverse strength, the three-point bending (n=7) test instrument (Lloyd NK5, Lloyd Instruments Ltd, Fareham Hampshire, UK) was used at 5 mm/min. A Dynatup 9250 HV (Instron, UK) device was employed for the impact strength (n=7). All of the resin samples were tested by using thermo-mechanical analysis (Shimadzu TMA 50, Shimadzu, Japan). The data were analyzed by Kruskal-Wallis and Tukey tests for pairwise comparisons of the groups at the 0.05 level of significance.

RESULTS

In all mechanical tests, the highest values were observed in Valplast group (transverse strength: 117.22 ± 37.80 MPa, maximum deflection: 27.55 ± 1.48 mm, impact strength: 0.76 ± 0.03 kN). Upon examining the thermo-mechanical analysis data, it was seen that the E value of the control sample was 8.08 MPa, higher than that of the all other samples.

CONCLUSION

Although Valplast denture material has good mechanical strength, its elastic modulus is not high enough to meet the standard of PMMA materials.     

聚酰胺柱色谱分离纯化野菊花中黄酮苷研究

目的:研究聚酰胺柱色谱分离纯化野菊花中黄酮苷类-蒙花苷的工艺条件.方法:以野菊花中蒙花苷的解析率与纯度为指标,通过考察静态、动态吸附试验,优化聚酰胺分离纯化野菊花中蒙花苷的工艺条件.结果:聚酰胺对黄酮苷有良好的分离效果,其优化工艺为:最佳上柱样品溶液质量浓度2.0 mg· ml-1,吸附流速2 BV· h-1,10%乙醇除杂液和50%乙醇洗脱液分别以1 BV· h-1速度洗脱.蒙花苷动态饱和吸附量7.582 mg·g-1,蒙花苷动态解析率为91.27%,纯度达到12.63%.结论:聚酰胺对野菊花中蒙花苷分离纯化性能较高,纯度提高了5.2倍.可用于野菊花中黄酮苷类-蒙花苷的进一步分离与纯化.     

美洲大蠊提取物对3株人体呼吸系统肿瘤细胞的细胞毒性研究

目的通过2对美洲大蠊提取物的肿瘤细胞毒性测试,探讨美洲大蠊提取物的抗肿瘤作用。方法美洲大蠊醇提取物,通过聚酰胺柱层析分离划段得不同部位,采用MTT法对所得部位进行肿瘤细胞毒性测试。结果有多个部位样品的IC50值小于10μg/ml。结论通过样品与对照品细胞毒活性结果比较,表明美洲大蠊提取物中存在具有肿瘤细胞生长抑制作用的物质,值得对其进行进一步的研究。     

Posterior-Reversible-Encephalopathy Syndrome and Antepartum Eclampsia

Objectives

To compare the efficacy of three suture materials, i.e., poliglecaprone 25, polyglactin 910, and polyamide, as subcuticular skin stitches in post-cesarean women.

Study Design

This was a randomized clinical trial.

Population

The study was conducted in the department of obstetrics and gynecology of a tertiary institute, LTMMC, Sion, Mumbai, India. Only those women undergoing emergency cesarean section were included.

Methods

The study was conducted in the department of obstetrics and gynecology of a tertiary institute, LTMMC, Sion, Mumbai, India. 90 women undergoing emergency cesarean section were included and divided into three groups. In group 1, poliglecaprone 25 was used as subcuticular skin stitches; in group 2, polyglactin 910 was used as subcuticular skin stitches; and in group 3, polyamide was used as subcuticular skin stitches.

Results

Thirty percentage of the patients in group 3 had discomfort on day 10, while it was only 3.3 % in group 1. In group 1, 6.6 % patients had swelling and indurations, while it was 33.3 % in group 2 on day 4. Wound dehiscence was present in 3.3 % patients in group 1, 26.6 % in group 2, and 6.6 % in group 3. Regarding wound healing, 93.3 % patients had excellent wound healing in group 1, 66.6 % in group 2, and 86.6 % in group 3.

Conclusions

The results were almost similar with poliglecaprone and polyamide, except for discomfort which was present more in patients in group 3.     

Development of biomimetic nano-hydroxyapatite/poly(hexamethylene adipamide) composites

In this study, acicular nano-hydroxyapatite (n-HA) was used to make a new biomimetic composite with polyamide (poly hexamethylene adipamide) by a unique technique. The physical and chemical characteristics of the composites were tested. It was found that these synthesized n-HA crystals were similar to bone apatite in size, phase composition and crystal structure. The biomimetic n-HA crystals were uniformly distributed in the polymer matrix and its content can reach 65%, close to that in natural bone. Chemical binding between inorganic n-HA and polyamide was investigated and discussed. The mechanical properties of the composites were found to match well with those of natural bone.     

Cytocompatible Performance of Thermosensitive Poly(N-Isopropylacrylamide) Nanoparticles

Abstract

The development of biomedical materials with biocompatibility, especially cytocompatibility, is the frontal research field for material science, biology, medicine, pharmacology and related interdisciplines. We have successfully synthesized a new biomedical material, PNIPAM-g-P(NIPAMco-St) (PNNS) core-shell nanoparticles, and investigated its thermosensitive and fluorescent properties. In order to evaluate the cytocompatibility of the PNNS nanoparticles, the effect of the PNNS nanoparticles on the human ether-àgo-go-related gene (hERG) K⁺ channel in HEK-293 cells was investigated for the first time with the inverted fluorescence microscope and the whole-cell patch-clamp technique. The PNNS nanoparticles can be adsorbed on the surface of the cell membrane of HEK-293 cells, and cannot change the structure of HEK-293 cells. The low concentration of the PNNS nanoparticles can slightly inhibit the stable and tail current of the hERG K⁺ channel, left-shift the activation curve of the hERG K⁺ channel and decrease the deactivation time constant (τ)of the hERG K⁺ channel. However, in the presence of the high concentration of the PNNS nanoparticles, the changes mentioned above gradually return to the level in the absence of the PNNS nanoparticles. These results indicated that the PNNS nanoparticles can not damage the cells. Thus, the PNNS nanoparticles have a good cytocompatibility and might be applied as a biomedical material.