Macroporous thin membranes for cell transplant in regenerative medicine

The aim of this paper is to present a method to produce macroporous thin membranes made of poly (ethyl acrylate-co-hydroxyethyl acrylate) copolymer network with varying cross-linking density for cell transplantation and prosthesis fabrication. The manufacture process is based on template techniques and anisotropic pore collapse. Pore collapse was produced by swelling the membrane in acetone and subsequently drying and changing the solvent by water to produce 100 microns thick porous membranes. These very thin membranes are porous enough to hold cells to be transplanted to the organism or to be colonized by ingrowth from neighboring tissues in the organism, and they present sufficient tearing stress to be sutured with surgical thread. The obtained pore morphology was observed by Scanning Electron Microscope, and confocal laser microscopy. Mechanical properties were characterized by stress–strain experiments in tension and tearing strength measurements. Morphology and mechanical properties were related to the different initial thickness of the scaffold and the cross-linking density of the polymer network. Seeding efficiency and proliferation of mesenchymal stem cells inside the pore structure were determined at 2 h, 1, 7, 14 and 21 days from seeding.     

Long-term follow-up of camouflage effects following resin infiltration of post orthodontic white-spot lesions in vivo

Objectives:To reassess the long-term camouflage effects of resin infiltration (Icon, DMG, Hamburg, Germany) of white spot lesions (WSL) and sound adjacent enamel (SAE) achieved in a previous trial. The null hypothesis was tested that there were no significantly different CIE-L*a*b*-ΔE-values between WSL and SAE areas of assessment after at least 24 months (T24) compared to those at baseline (T0).Materials and Methods:Of twenty subjects who received previous resin infiltration treatment of n_teeth = 111 nonrestored, noncavitated postorthodontic WSL after multibracket treatment during a randomized controlled trial and were contacted 20 months after baseline, eight subjects (trial teeth n_teeth = 40; m/f ratio 1/7; age range (mean; SD) 12–17 [15.25; 2.12] years); response rate: 40%) were available for follow-up after at least 24 months (T24). CIE-L*a*b* differences between summarized color and lightness values (ΔE_WSL/SAE) of WSL and SAE were assessed using a spectrophotometer and compared to baseline data assessed prior to infiltration (T0), and those after 6 (T6), and 12 (T12) months using paired t tests at a significance level of α = 5%.Results:T24 assessments were performed after a mean 33.86 (SD: 8.64; Min: 24; Max: 45) months following T0. Mean (SD) ΔE_WSL/SAE units of available teeth were 8.76 (5.33) at baseline; 5.5 (2.75) at T6; 5.2 (2.41) at T12; and 5.57 (2.6) at T24. Comparisons of T6, T12, and T24 with T0 yielded highly significant differences, whereas T6–T24 and T12–T24 differences were found to be not significant.Conclusions:Assimilation of infiltrated WSL to the color of adjacent enamel by resin infiltration is considered to be suitable for the long-term improvement in the esthetic appearance of postorthodontic WSL.     

Estenia瓷树脂复合体制作冠桥的强度测试

目的:探讨Estenia瓷树脂复合体的强度,并与其他几种树脂材料进行比较,为临床选择冠桥树脂材料提供参考。方法:采用Estenia瓷树脂复合体体外模拟下颌第一磨牙单冠和第一磨牙缺失3个单位固定桥的形态,测试单冠的抗压强度和固定桥的抗弯强度,并与Artglass、Solidex、Targis3种树脂材料在相同实验方法下测试得到的结果作比较。结果:Estenia瓷树脂单冠的折裂最大载荷均值为600.20N,Estenia瓷树脂桥的折裂最大载荷均值为302.53N。结论:Estenia瓷树脂复合体的强度高于Artglass﹑Solidex和Targis树脂复合体。     

用于牙科复合树脂的具有固位力外形的无机填料的研究

本文介绍了一类微细的复合式无机填料。由于具有特殊的表面结构，这类填料与复合树脂中的树脂基质之间有良好的结合力，因此称之为“具有固位力外形的无机填料”。用此类填料配制的试验性复合树脂，不仅其磨耗性能有明显的改善，而且其它机械性能也有不同程度的提高。     

Expansion of human nasal chondrocytes on macroporous microcarriers enhances redifferentiation

Articular cartilage has a limited capacity for self-repair. To overcome this problem, it is expected that functional cartilage replacements can be created from expanded chondrocytes seeded in biodegradable scaffolds. Expansion of chondrocytes in two-dimensional culture systems often results in dedifferentiation. This investigation focuses on the post-expansion phenotype of human nasal chondrocytes expanded on macroporous gelatin CultiSpher G microcarriers. Redifferentiation was evaluated in vitro via pellet cultures in three different culture media. Furthermore, the chondrogenic potential of expanded cells seeded in polyethylene glycol terephthalate/ polybuthylene terephthalate (PEGT/PBT) scaffolds, cultured for 14 days in vitro, and subsequently implanted subcutaneously in nude mice, was assessed.

Chondrocytes remained viable during microcarrier culture and yielded doubling times (1.07±0.14 days) comparable to T-flask expansion (1.20±0.36 days). Safranin-O staining from pellet culture in different media demonstrated that production of GAG per cell was enhanced by microcarrier expansion. Chondrocyte–polymer constructs with cells expanded on microcarriers contained significantly more proteoglycans after subcutaneous implantation (288.5±29.2 μg) than those with T-flask-expanded cells (164.0±28.7 μg). Total collagen content was similar between the two groups.

This study suggests that macroporous gelatin microcarriers are effective matrices for nasal chondrocyte expansion, while maintaining the ability of chondrocyte differentiation. Although the exact mechanism by which chondrocyte redifferentiation is induced through microcarrier expansion has not yet been elucidated, this technique shows promise for cartilage tissue engineering approaches.     

正交设计法优化黄连提取液大孔树脂洗脱条件

目的：选择大孔树脂纯化黄连提取液的最佳洗脱条件。方法：以洗脱液中季铵碱的含量作指标，选择洗脱液乙醇浓度、用量、盐酸浓度3个因素，用L9(3^4)正交表安排实验，优化了洗脱条件。结果：对黄连季铵碱从大孔树脂上洗脱效率，洗脱液用量(B)具有非常显的影响，洗脱液乙醇浓度(A)的影响显，盐酸浓度(C)的影响无显性意义；A2B3C1为优选出的最佳洗脱条件。结论：本实验条件下选定的洗脱条件能够完全洗脱吸附在大孔树脂上的黄连季铵碱。     

高效液相色谱法测定参芍颗粒中芍药苷的含量

目的　建立参芍颗粒中芍药苷的含量测定方法。方法　高效液相色谱法 (HPL C) ,VP- ODS柱 ,流动相甲醇 - 0 .5 m ol/L磷酸二氢钾溶液 -醋酸 -异丙醇 (6 7∶ 1 73∶ 4∶ 4 ) ,检测波长 2 30 nm。结果　芍药苷在 0 .2 4μg～ 1 .2 0μg呈良好的线性关系 ,r=0 .9998,平均回收率 97.98% ,RSD 1 .6 7 (n=9)。结论　本法简便、准确、灵敏度高、重复性好 ,可用于该制剂成分的含量测定     

刺五加提取物大孔树脂精制试验

目的　为了提高异嗪皮啶活性成分含量 ,采用大孔树脂 ,考察刺五加提取物精制过程。方法　采用大孔树脂为材料 ,吸附刺五加提取物 ,70 %乙醇溶液洗脱提取物 ;用HPLC法测定精制前后异嗪皮啶含量。结果　刺五加提取物经过大孔树脂精制后 ,其活性成分之一异嗪皮啶含量提高了 5倍。结论　大孔树脂在中药提纯过程中有重要应用价值     

大孔吸附树脂纯化断血流总皂苷工艺研究

目的:研究大孔吸附树脂纯化断血流总皂苷的工艺条件及参数.方法:以洗脱率、精制度等为指标,考察大孔吸附树脂对断血流总皂苷的吸附性能和洗脱参数.结果:11.4ml断血流总皂苷样品液(生药0.2g/ml)上大孔吸附树脂(φ15mm×H90mm,干重2.5g),用蒸馏水,30%、70%乙醇各3BV依次洗脱,断血流总皂苷富集于70%乙醇洗脱液部位.结论:采用大孔吸附树脂技术富集、纯化断血流总皂苷,其洗脱率为86.8%,精制度为153.2%,该法可较好地纯化断血流总皂苷.     

RP-HPLC制备色谱法分离淡豆豉中高纯度异黄酮苷元

淡豆豉经大孔树脂柱色谱初步分离纯化,采用RP-HPLC制备色谱法,乙腈-水-冰醋酸(35∶ 65∶ 1,v/v/v)为流动相,流速3.0 ml/min,检测波长260 nm.结果表明,在30 min内快速分离到大豆素、大豆黄素和染料木素,产物纯度均达到99%以上.