Study and evaluation of mechanisms of dual targeting drug delivery system with tumor microenvironment assays compared with normal assays

A dual targeting delivery system was developed to completely conquer the two barriers that glioma treatment faces: the blood–brain barrier (BBB) and the brain–glioma barrier. Recently, a system comprising AS1411 aptamer (for glioma targeting) and TGN peptide (for BBB targeting) modified nanoparticles (AsTNPs) was developed, which can effectively target brain glioma and improve the survival of glioma-bearing mice. However, the in vitro models currently used are far too different from the in vivo tumor microenvironment that the glioma targeting delivery system actually faces. In this study, the pharmacology mechanisms of AsTNPs were explored in several models that imitated the tumor microenvironment. AsTNPs can be selectively taken up by endothelial and glioma cells, effectively penetrating the BBB and brain–glioma barriers to reach glioma cells and display their anti-glioma effect. The cell monolayers, tumor spheroids and coculture systems were more suitable in vitro models for the pharmacology evaluation of targeted drug delivery systems.     

Porous polyvinyl alcohol hydrogel composite prepared and studied initially for biocompatibility]

OBJECTIVE: To investigate the feasibility of porous polyvinyl alcohol hydrogel (PVA-H) composite, for tissue engineering scaffold. METHODS: The approach of emulsifier-foaming, freeze-drying and surfactant-cleaning method was developed to gain three kinds of porous scaffolds: porous polyvinyl alcohol (PVA), porous polyvinyl alcohol/nano-hydroxyapatite (PVA/n-HA) and porous polyvinyl alcohol/chitosan (PVA/Cs). We checked the physical features of the above three kinds of materials and further investigated their biocompatibility by SEM image analysis, mechanics test, MTT and muscle implanting. RESULTS: Three kinds of materials had the similar character of high porosity (80%), but the PVA/n-HA had the smallest mean pore size (154.5 microm) and the PVA had the biggest tensile strength (0.60 Mpa). MTT assay demonstrated three kinds of materials to have no toxicity, furthermore, PVA had better absorbance, compared with cell control group (P < 0.05). After muscle implantation, there were many muscular tissues growing into pores of PVA/Cs at the 4th week, although PVA/Cs had stronger inflammatory reaction. Other two kinds of materials had very small inflammatory reaction and there were many fibrous tissues growing into pores at the 1st, 4th, 12th week. CONCLUSION: The features of materials are changed after adding n-HA or Cs, moreover, porous PVA/Cs seems to have the activity of inducing muscle growth. Porous PVA and its composites may be applied to tissue engineering as a long-term or permanent scaffold due to their good biocompatibility, elasticity and hydrophilicity.     

脊索细胞促进髓核软骨样细胞增殖及表型维持

目的分离纯化兔髓核中的细胞成分，观察脊索细胞形态及对软骨样细胞增殖及细胞表型的影响。方法6只4周龄新西兰兔胸腰段脊柱，获取髓核，0．2％Ⅱ型胶原酶消化法及不连续密度梯度法分离纯化脊索细胞及软骨样细胞。实验分为单纯软骨样细胞培养组（A组）及脊索细胞、软骨样细胞（1：1）共培养组（B组）。倒置相差显微镜观察两组细胞生长情况，测定两组原代及传代细胞成活率，MTT法测定两组第2代细胞增殖曲线，并以甲苯胺蓝染色和免疫细胞化学染色鉴定两组原代及传代细胞蛋白多糖及Ⅱ型胶原的表达。结果成功分离、纯化脊索细胞和软骨样细胞。细胞培养观察，原代脊索细胞直径10～15gm，胞浆内富含大小不等的囊泡；原代软骨样细胞直径4～6gm，胞浆内无囊泡。各代细胞成活率A组为89．0％～95．3％，B组为91_3％～96．3％，各代细胞成活率两组间比较差异无统计学意义（P〉0．05）。A组细胞培养3～4d进入对数生长期，B组细胞培养2d后进入对数生长期；培养4d后，B组细胞增殖能力高于A组，差异有统计学意义（P〈0．05）。A组3代以内细胞表达蛋白多糖及Ⅱ型胶原，B组细胞表型维持至5代。结论脊索细胞能促进髓核软骨样细胞的增殖及表型维持；脊索细胞可能在防止椎间盘退变中具有重要意义。     

大鼠成骨细胞增殖及护骨素蛋白含量与甲状旁腺激素的调节效应

目的:体外观察甲状旁腺激素对大鼠成骨细胞增殖和护骨素分泌的调节作用。方法:实验于2005-06/2006-05在四川大学华西医院生物治疗国家重点实验室干细胞与组织工程研究室完成。采用酶消化法和骨组织块法联合分离培养新生SD大鼠颅骨成骨细胞,间歇加药方法将不同浓度0,10-6,10-7,10-8,10-9mol/L甲状旁腺激素作用于大鼠成骨细胞(0mol/L作为空白对照组),经碱性磷酸酶染色及钙结节茜素红染色证实培养的成骨细胞后,采用四甲基偶氮唑盐比色法检测细胞增殖能力,蛋白免疫印迹测定护骨素的分泌量。结果:①成骨细胞的形态变化:倒置相差显微镜下可见培养的成骨细胞呈短梭形、三角形和多边形。碱性磷酸酶染色光镜下可见成骨细胞胞浆中分布特征性蓝紫色细颗粒;成骨细胞的钙结节在镜下可见部分细胞聚集一起呈"集落状"生长。②成骨细胞增殖率:10-6～10-9mol/L浓度甲状旁腺激素对成骨细胞增殖均显示刺激作用,与空白对照组相比,差异显著(P<0.05),增殖率以10-8mol/L甲状旁腺激素组最高。③成骨细胞护骨素的表达:甲状旁腺激素下调成骨细胞中护骨素的分泌,与空白对照组相比,10-6mol/L甲状旁腺激素组抑制作用最明显(P<0.01),无显著剂量依赖性。结论:甲状旁腺激素对体外培养成骨细胞的增殖具有明显促进作用,通过下调成骨细胞中护骨素的分泌,促进破骨细胞生成、活化,促进骨吸收。     

n-HA/PA66生物材料修复骨巨细胞瘤骨缺损效果的临床研究

目的观察颗粒型纳米羟基磷灰石/聚酰胺66(n-HA/PA66)修复骨巨细胞瘤骨缺损的生物安全性和临床效果。方法选取2007年12月至2011年5月于我院行病灶刮除、颗粒型n-HA/PA66填充植骨术的骨巨细胞瘤患者48例,术前及术后做血常规、肝肾功、钙磷及免疫相关检查,术后1周,1、3、6、12月及以后每6月行影像学检查。将1例复发患者再手术时取出的含有n-HA/PA66复合生物材料的骨组织行组织学检查。结果 3例失访,45例获得随访。患者术前、术后的血常规、肝肾功、钙磷、免疫指标均无明显变化。除1例复发外,余影像学示材料颗粒随时间逐渐融合,植骨区密度逐渐增高,与宿主骨界限逐渐模糊。术后1年,植骨区密度接近正常骨密度。组织学检查示:成骨细胞爬入材料的孔隙内,周围钙盐沉着明显,大量骨细胞镶嵌于材料中,材料与新生骨及周围组织结合紧密。结论 n-HA/PA66具有良好的生物安全性和组织相容性,良好的骨传导性及成骨活性,是一种理想的骨修复材料。     

Mid-term results using a cementless hip prosthesis in young Chinese patients: a five- to seven-year follow-up study

A retrospective study was undertaken to evaluate the clinical and radiographic outcomes of 74 cementless total hip arthroplasties (THA) in 69 young Chinese patients. The Asian size and MMA AML stems with smoothly tapered tip were used, and the patients were followed up for at least five years. The mean Harris hip score was 45.4 preoperatively and 95.3 at the last follow-up. The incidence of thigh pain was 5.4%, and was related to the short stature of the patient (<160 cm) (P = 0.030). Six patients (6 hips, 8.1%) had acetabular osteolysis in zone 2; reoperation was performed in one patient because of osteolysis and wear of the polyethylene liner. The survival rate of the metal acetabular and femoral components was 100% (95% confidence interval, 0.95–1.0). Primary THA with this AML prosthesis had an acceptable mid-term result in young Chinese patients.     

软骨素酶ABC促进大鼠脊髓损伤后轴突再生和功能恢复的初步研究

目的探讨软骨素酶ABC（ChABC）对大鼠脊髓横断损伤（SCI）后轴突再生和功能恢复的影响。方法SD大鼠随机分为实验组（SCI＋ChABC）,对照组（SCI＋NS）及正常组。采用T2-8脊髓完全横断模型,术后2周和10周脊髓标本分别行OBT、GFAP、NSE及NF免疫组化染色,术后1、2、3、4、5、6、8、10周进行行为学评分。结果行为学评分,术后3周实验组评分高于对照组（P〈0．05）,同时实验组疤痕中OBT和GFAP染色低于对照组（P〈0．05）,GFAP和NF染色高于对照组（P〈0．05）。结论ChABC能有效降低损伤部位硫酸软骨素蛋白多糖（CSPGs）的活性,从而促进SCI大鼠感觉、运动功能的恢复和轴突的再生。     

Coflex棘突间动力重建术与360°融合术治疗单节段腰椎退变性疾病的成本-效用分析

目的 从卫生经济学角度对Coflex棘突间动力重建术与360°融合术治疗单节段腰椎退变性疾病进行成本-效用分析,为临床医生及单节段腰椎退变性疾病患者选择最佳治疗方案提供参考.方法 对2008年10月至2010年11月期间,四川大学华西医院骨科采用后路减压联合Coflex棘突间动力重建术(A组)与椎间及后外侧360°植骨融合术(B组)治疗的腰4～5节段退变性疾病患者进行前瞻性非随机对照研究,以SF-36量表调查患者生活质量并计算质量调整生命年(QALY),同时收集治疗成本,比较两组的成本-效用比.结果 共纳入60例患者,其中A组29例,B组31例,平均随访16.4(12～23)月.其中A组男20例,女9例,年龄45.1(21～67)岁;B组男16例,女15例,年龄56.2(32～86)岁.A、B组医疗成本分别为51509.9:1:2422.9元、57409.7±9072.9元,生活质量分别较术前改善42.60%、42.82%,成本效用比分别为69 165.6± 716.0元/QALY、77 976.7±12 757.4元/QALY,A组每提高一个QAlY较B组可节约12.74%的成本.结论 Coflex棘突间动力重建术与360°融合术治疗单节段腰椎退变性疾病短期疗效相当.但比后者治疗成本低,更符合卫生经济学要求.