新型可吸收材料PLLA/PLLA-gHA的生物相容性

目的：对新型可吸收材料PLLA/PLLA-gHA的生物相容性进行综合性评价。方法：依据IS0 10993系列标准和GB/T 16886系列标准,对新型可吸收材料PLLA/PLLA-gHA进行急性全身毒性实验、溶血实验、肌肉内种植实验和皮内反应实验。小鼠尾静脉注射新材料浸提液,观察注射后各时相点动物的一般状态、毒性表现等指标以评价急性全身毒性反应。在100g•L^-1新材料浸提液加入新鲜抗凝兔血,用分光光度计测取吸光度并计算溶血率。白兔背部皮下注射新材料浸提液,观测各注射点的红斑和水肿情况。将PLLA/PLLA-gHA板植入白兔竖脊肌内,于各时相点抽取兔静脉血检测血液学指标,在术后第14、 30、 60、 90、 180和360天取材,行大体标本和病理组织切片观察。结果：新型可吸收材料PLLA/PLLA-gHA组白兔一般状态良好,无急性全身毒性反应,实验组与对照组各期血液学指标AST、Scr,比较差异无显著性（P>0.05）,新材料浸提液的溶血率为1.22%,低于标准规定的5%;皮下反应实验,各时相点组织水肿极轻微,无红斑形成;肌内植入PLLA/PLLA-gHA板实验,其早期炎性细胞侵润变化规律与对照组类似,符合一般的炎症变化转归规律,材料周围的包膜随植入时间的延长逐渐变薄,术后第360天时纤维化囊壁向材料内长入,囊壁形成程度为Ⅰ级以下。结论：新型可吸收材料PLLA/PLLA-gHA具有良好的生物相容性和安全性。     

形状记忆输卵管避孕材料的急性毒性研究

目的 探明形状记忆输卵管避孕材料的急性毒性,为临床的安全使用提供依据和资料.方法 形状记忆输卵管避孕材料浸提液腹腔注射给药,以最大允许给药剂量为最高剂量,观察小鼠的死亡率和脏器的感官病理改变.连续观察14d.结果 给药后,各种剂量下均未见中毒症状,动物活动自如,皮毛光滑,未出现死亡.存活动物体质量无明显变化;肉眼未见脏器明显的病理改变.结论 形状记忆输卵管避孕材料急性单次接触条件下的生物安全性良好.     

聚内消旋乳酸椎间融合器的生物力学测试

目的 研制用聚内消旋乳酸(PDLLA)制成椎间融合器,通过动物实验,考察其生物力学变化情况,为进一步加以改进和临床应用提供动物实验的基础.方法 通过光镜观察椎间植骨融合情况.通过生物力学测试,检测脊柱融合的不同阶段,使用可降解椎间融合器引起的椎间融合的生物力学变化.结果 椎间植骨融合良好.材料本身的力学强度高于骨组织,因此,早期的力学结果显示其抗压、抗扭强度均明显高于对照组.后期随着材料的降解,其力学特性也随之改变,逐渐与对照组结果相近.结论 材料对植骨融合无负面影响.PDLLA材料在椎间植骨融合过程中,可提供足够的力学强度.保证植骨部位的融合,避免塌陷.     

Understanding peroral absorption: regulatory aspects and contemporary approaches to tackling solubility and permeability hurdles

Oral drug absorption is a process influenced by the physicochemical and biopharmaceutical properties of the drug and its inter-relationship with the gastrointestinal tract. Drug solubility, dissolution and permeability across intestinal barrier are the key parameters controlling absorption. This review provides an overview of the factors that affect drug absorption and the classification of a drug on the basis of solubility and permeability. The biopharmaceutical classification system (BCS) was introduced in early 90׳s and is a regulatory tool used to predict bioavailability problems associated with a new entity, thereby helping in the development of a drug product. Strategies to combat solubility and permeability issues are also discussed.     

气相色谱-质谱联用法同时测定工作场所空气中44种挥发性有机物

目的 建立了一种同时测定工作场所空气中44种挥发性有机物的溶剂解吸-气相色谱质谱联用法。方法 采用溶剂解吸型活性炭管对工作场所的空气采样,二硫化碳解吸后经HP-VOC石英毛细管色谱柱(60 m×0.20 mm×1.12μm)分离,质谱检测器检测,标准曲线法定量。结果 被测组分线性相关系数均大于0.99,检出限在0.10～0.95μg/ml之间,相对标准偏差小于9.80%,平均解析率为61.23%～118.50%。应用该方法对33份样品进行分析,结果分别检出19种挥发性有机物,含量在0.10～604.43 mg/m³之间,其中超出职业接触限值的有苯乙烯(62.32～114.54 mg/m³)、甲苯(50.11～604.43 mg/m³)和二甲苯(79.61 mg/m³和91.55 mg/m³)三种有机物;并对5种原料进行定性识别,两种结果相符。结论 该方法具有较高的灵敏度和精密度,各项指标均满足工作场所空气中44种挥发性有机物分析的要求。     

高效液相色谱法对PHEMA液体栓塞材料中单体残留的超痕量分析

应用高效液相色谱法测定了聚甲基丙烯酸-β-羟乙酯(PHEMA)液体栓塞材料中的单体甲基丙烯酸-β-羟乙酯(HEMA)残留量。采用色谱柱Aichrom Bond-1 C18(4.6 mm×250 mm,5μm)进行分离,流动相为乙腈-水(30∶70);检测波长为220 nm;进样量为20μL。单体在质量浓度为0.1~4.0 mg/L的范围,峰面积与单体浓度线性关系良好,相关系数0.9992,检测下限为0.01 mg/L。当试样加标浓度为0.5,2.0,4.0 mg/L时,加标回收率在99.5%~102.0%之间,RSD≤2%。     

Case studies putting the decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping) into practice

Case studies covering carbonaceous nanomaterials, metal oxide and metal sulphate nanomaterials, amorphous silica and organic pigments were performed to assess the Decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping). The usefulness of the DF4nanoGrouping for nanomaterial hazard assessment was confirmed. In two tiers that rely exclusively on non-animal test methods followed by a third tier, if necessary, in which data from rat short-term inhalation studies are evaluated, nanomaterials are assigned to one of four main groups (MGs). The DF4nanoGrouping proved efficient in sorting out nanomaterials that could undergo hazard assessment without further testing. These are soluble nanomaterials (MG1) whose further hazard assessment should rely on read-across to the dissolved materials, high aspect-ratio nanomaterials (MG2) which could be assessed according to their potential fibre toxicity and passive nanomaterials (MG3) that only elicit effects under pulmonary overload conditions. Thereby, the DF4nanoGrouping allows identifying active nanomaterials (MG4) that merit in-depth investigations, and it provides a solid rationale for their sub-grouping to specify the further information needs. Finally, the evaluated case study materials may be used as source nanomaterials in future read-across applications. Overall, the DF4nanoGrouping is a hazard assessment strategy that strictly uses animals as a last resort.     

光固化3D打印软组织材料的性能研究进展

光固化3D打印技术具有成型速度快、精度高的特点,可以精确控制需打印软组织的大小、形状和强度等,完成所需替代软组织支架的高匹配定制,有效解决软组织替代物的巨大缺口。目前该技术的应用范围取决于光敏材料的性能,首先,需具备适当的黏度、固化时间和固化收缩率等,以执行光固化打印并能控制打印组织的精度;其次,打印组织还需满足机体使用的机械性能(如强度、硬度、韧性)和良好的生物相容性(如促细胞黏附、增殖及分化),而降解性质、孔隙率、血管化等直接影响打印组织的机械性能或生物相容性。综述软组织支架打印所需光敏材料的基本性能和特殊性能要求及目前改良材料性能的方法,并展望光敏材料的发展趋势,对软组织工程光敏打印材料的开发具有指导意义。     

Lateral alveolar ridge augmentation using a synthetic nano-crystalline hydroxyapatite bone substitution material (Ostim): preliminary clinical and histological results

OBJECTIVES: The purpose of this preliminary two-center clinical prospective study was to evaluate the tissue composition of augmented sites after the use of a nano-crystalline hydroxyapatite (ncHA) bone substitution material by clinical and histological examinations. MATERIAL AND METHODS: A synthetic ncHA augmentation material was used without any additives in 14 patients requiring lateral ridge augmentation 6-7 months before (10 patients) or at implant placement (four patients). The ncHA material was covered by a titanium mesh for space maintenance. Clinical and radiographic parameters were evaluated and bone biopsy cores, obtained 6-7 months following augmentation, were assessed histologically and histomorphometrically. RESULTS: One patient showed gingival swelling, redness and pain at the augmentation site requiring removal of the titanium mesh 6 weeks postoperatively. In seven patients, a premature exposure of the titanium mesh without any inflammatory symptoms was noted. The width of the fixed gingival and the alveolar ridge height did not change significantly at least 6 months following augmentation (P>0.5), whereas a significant gain in alveolar ridge width (P=0.01) was noted. After a median period of prosthetic loading of 24 months, no implant was considered to be a failure. Histology revealed ncHA remnants in peripheral and central parts of biopsy cores obtained from seven patients after at least 6 months without histological symptoms of inflammation, whereas histomorphometry of bone cores revealed no significant differences of the mean percentage area of ncHA in peripheral (23.4%) and central (15.1%) parts of biopsy cores (P=0.262). The mean percentage area of bone colonizing the defect was 52.3%. CONCLUSIONS: Small amounts of ncHA were found after at least 6 months in bone biopsies. The former defect space was filled with bone. The alveolar ridge width gain was found to be significant after lateral augmentation utilizing ncHA, providing a quantitatively and qualitatively sufficient site for primary stable implant placement.