碱性成纤维细胞生长因子对许旺细胞在小肠黏膜下层支架上黏附及增殖的影响

背景:许旺细胞复合小肠黏膜下层是构建人工神经的可行方法,碱性成纤维细胞生长因子有促进许旺细胞增殖的作用。目的:验证碱性成纤维细胞生长因子对许旺细胞在小肠黏膜下层支架材料表面的细胞增殖及黏附状态的影响。方法:将体外分离培养的2代SD乳鼠许旺细胞接种于小肠黏膜下层支架材料上并加入50μg/L的碱性成纤维细胞生长因子复合培养为实验组,以单纯的许旺细胞复合小肠黏膜下层作为对照组,分别用MTT法测定细胞增殖能力,细胞黏附率检测细胞在支架上的黏附情况,用流式细胞仪测定细胞分裂周期,并用苏木精-伊红染色及描电镜观察细胞形态及与材料的贴附情况。结果与结论:MTT显示实验组的细胞增殖吸光度值明显高于对照组(P0.05),实验组的细胞黏附率为(69.47±3.17)%,对照组为(44.58±1.76)%(P0.05),细胞周期显示实验组比对照组的G2/M+S期细胞百分含量高(P0.05),培养7d后的苏木精-伊红染色及扫描电镜显示实验组比对照组材料上聚集的细胞数量多,细胞形态伸展更明显,细胞贴附力更好。因此碱性成纤维细胞生长因子可明显地改善许旺细胞在小肠黏膜下层上的增殖及黏附能力,能促进许旺细胞与小肠黏膜下层支架的复合而构建人工神经导管。     

丝素蛋白/羟基磷灰石支架对成骨诱导脂肪干细胞活性及成骨性能的影响

背景：成骨诱导后的脂肪干细胞与可降解丝素蛋白/羟基磷灰石支架复合,可望研制出一种具有良好生物相容性及成骨性能的新型骨融合材料。 目的：探讨丝素蛋白/羟基磷灰石支架对成骨诱导脂肪干细胞增殖活性及成骨性能的影响。 方法：获取大鼠脂肪干细胞后体外贴壁培养、扩增,将第3代细胞用条件培养液进行成骨方向的定向诱导培养、扩增,然后接种到预湿的丝素蛋白/羟基磷灰石材料上作为实验组,以相同条件下置入盖玻片和脂肪干细胞培养作为对照组。倒置相差显微镜观察细胞在材料中的生长情况,MTT法检测材料对细胞增殖活性的影响,碱性磷酸酶活性测定评价其成骨能力。 结果与结论：成骨诱导后的脂肪干细胞在丝素蛋白/羟基磷灰石材料上能够良好地黏附和增殖。实验组和对照组细胞增殖活性及碱性磷酸酶活性比较,差异无显著性意义(P > 0.05),证实脂肪干细胞活性及成骨性能不受材料影响,说明丝素蛋白/羟基磷灰石复合材料具有良好的细胞相容性。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Bio-Gide胶原膜对兔骨髓间充质干细胞增殖和成骨分化的影响

背景：相关实验表明Bio-Gide胶原膜与细胞有良好的生物相容性,但有关与其复合培养干细胞成骨分化能力的报道少见。 目的：观察Bio-Gide胶原膜对骨髓间充质干细胞增殖及成骨分化的影响。 方法：全骨髓贴壁法体外分离培养兔骨髓间充质干细胞,将第3代兔骨髓间充质干细胞分别接种于覆盖Bio-Gide胶原膜的培养板(实验组)与单纯培养板(对照组)培养。于培养1,4,7,14 d利用CCK-8试剂盒检测细胞增殖;成骨分化诱导培养1,4,7,14 d收集细胞培养液上清,检测细胞碱性磷酸酶活性。 结果与结论：两组细胞数量均随着培养时间的增加而不断增加,对照组培养7 d细胞数量明显多于实验组(P < 0.05),其他时间点组间比较差异无显著性意义。两组细胞碱性磷酸酶活性均随着培养时间的增加而不断增加,实验组成骨诱导14 d细胞碱性磷酸酶活性高于对照组(P < 0.05),其他时间点组间比较差异无显著性意义。表明Bio-Gide胶原膜可促进兔骨髓间充质干细胞的增殖及成骨分化。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

骨髓间充质干细胞与不同基质修饰的纳米晶胶原基骨体外生物相容性研究

研究大鼠骨髓间充质干细胞(MSCs)诱导培养后与不同基质修饰的纳米晶胶原基骨(nanoHydroxyapatite/collagen,nHAC)的生物相容性,为骨组织工程提供一种新型复合支架材料。SD大鼠MSCs经成骨诱导培养、扩增,进行成骨细胞表征后,种植与支架材料体外复合培养。实验分为4组:实验组A,纤维蛋白(FB)和纤维连接蛋白(FN)修饰的纳米晶胶原基骨((FB FN)-nHAC);实验组B,纤维蛋白修饰的纳米晶胶原基骨(FB-nHAC);实验组C,纤维连接蛋白修饰的纳米晶胶原基骨(FN-nHAC);对照组D,单纯的纳米晶胶原基骨(nHAC)。通过检测支架材料的细胞黏附率、不同时间点(3、7、10、14d)支架材料中细胞数、碱性磷酸酶活性以及扫描电镜观察细胞在材料上的生长状况,比较分析不同支架材料与细胞生物相容性差异。大鼠MSCs经诱导培养14d后,碱性磷酸酶细胞化学染色、I型胶原免疫荧光染色及矿化沉积茜素红染色均为阳性;细胞与支架材料黏附率A组最高为74.4%;支架材料中细胞数量均随培养时间延长而增长,且A组细胞数增加较快,与相同时相点其他各组材料中细胞数差异有显著性(P<0.05);各时相点细胞碱性磷酸酶活性表达A组最高,差异亦有显著性(P<0.05)。电镜观察发现4组材料上均有细胞生长,但A组的细胞生长状况明显好于其他组。大鼠MSCs经成骨诱导培养,可表达成骨细胞表型,(FB FN)-nHAC在体外实验中表现出与细胞优良的生物相容性,可作为较理想的新型复合支架应用于骨组织工程。     

纳米晶胶原基骨/血管内皮生长因子缓释支架对人骨髓间充质干细胞体外粘附增殖的影响

研制纳米晶胶原基骨(nHAC)/血管内皮生长因子(VEGF)缓释支架,了解VEGF体外缓释效果及对人骨髓间充质干细胞(human mesenchymal stem cells,hMSCs)成骨诱导后粘附、增殖的影响,为骨组织工程寻求一种新型复合支架材料.利用生物学方法将VEGF负载于nHAC,制备具有VEGF缓释效果的复合支架;hMSCs经体外培养、扩增、成骨诱导后种植于VEGF缓释支架上行体外增殖.分为四组:实验组A:nHAC、纤维连接蛋白(fibronectin,FN)、肝索(heparin,HP)和VEGF(nHAC-FN-HP-VEGF);对照组B:nHAC、FN和VEGF(nHAC-FN-VEGF);对照组C,nHAC、HP和VEGF(nHAC-HP-VEGF);对照组D:nHAC和VEGF(nHAC-VEGF).通过检测支架材料上VEGF的释放量和持续时间,及种植细胞后细胞的黏附率、不同时间点(3、7、10、14 d)支架材料中细胞数、碱性磷酸酶活性以及扫描电镜观察细胞在材料上的生长状况,比较分析不同复合支架材料对细胞粘附、增殖的影响.人第三代MSCs 经诱导培养14 d后,碱性磷酸酶细胞化学染色、Ⅰ型胶原免疫荧光染色均为阳性;实验组A的VEGF缓释量最高,持续时间最长(可达14 d),细胞黏附率最高,为61.8%;各组支架中的细胞数量均随培养时间延长而增长,实验组A的细胞数增加较快,与相同时间点其他各组材料中细胞数差异有显著性(P<0.05);各时间点细胞碱性磷酸酶活性表达实验组最高,差异亦有显著性(P<0.05).电镜打描发现4组材料上均有细胞生长,实验组A的细胞增殖、分化状况明显好于其他组.hMSCs经诱导培养后可具有成骨细胞特性,hHAC-FN-HP-VEGF缓释支架具有较好的VEGF缓释效果,能显著提高细胞的粘附和增殖,可作为较理想的新型复合支架应用于骨组织工程.     

壳聚糖-明胶-果胶膜对骨髓基质干细胞的细胞行为研究

目的 考察壳聚糖-明胶-果胶膜对骨髓基质干细胞（MSC）的作用,为组织工程提供一种新的可望用于组织工程的生物材料. 方法 将MSC接种到壳聚糖-明胶-果胶（CS-Gel-P）膜和壳聚糖-明胶（CS-Gel）膜上,观察其生长形态,用MTT法测定其细胞活性,并考察其碱性磷酸酶活性表达. 结果 在CS-Gel-P膜上接种的MSC表现出比在CS-Gel膜和组织培养板（TCPS）上更好黏附性能,同时在不同时间点的碱性磷酸酶表达也均高于CS-Gel膜,在两种不同膜上的MSC的细胞活性差异无统计学意义. 结论 果胶的加入可以促进MSC的黏附和生长,同时更能促进MSC诱导分化为成骨细胞.     

钛表面微弧氧化涂层的细胞生物活性

背景：微弧氧化技术可改善钛或钛合金的表面特征。 目的：研究纯钛表面微弧氧化涂层的表面性能及其对MC3T3-E1细胞早期黏附、增殖及成骨能力的影响。 方法：将46个直径10 mm、厚度2 mm圆盘状纯钛试件分为实验组和对照组。实验组置于含0.02 mol/Lβ-甘油磷酸二钠盐及0.2 mol/L乙酸钙的电解液中进行微弧氧化处理,对照组对试件进行机械抛光。扫描电子显微镜观察试件表面形貌,X射线能谱分析检测涂层表面钙磷比,X射线衍射分析检测涂层晶相构成。将MC3T3-E1细胞接种在两组试件表面,1,2,4 h电镜下观察细胞形态,在2,4,7 d通过CCK-8方法检测细胞增殖,并于7,14 d检测碱性磷酸酶活性。 结果与结论：经微弧氧化处理后,钛表面形成粗糙多孔的钙磷涂层,微弧氧化涂层主要元素为Ca、P、O及Ti,微弧氧化膜层主要由氧化钛、钛酸钙、磷酸钙及偏磷酸钙构成。电镜观察显示1 h 微弧氧化涂层表面细胞已伸出伪足,4 h呈现较典型的细胞形态。细胞在微弧氧化处理钛表面4,7 d的细胞增殖和7,14 d的碱性磷酸酶活性高于对照组。表明微弧氧化技术生成的粗糙多孔钙磷涂层能显著促进MC3T3-E1细胞的早期黏附、增殖及成骨活性。     

体外构建组织工程骨-软骨复合组织

背景：设计一体化、具有过渡结构的双层支架材料,复合软骨细胞、骨髓间充质细胞,有利于新生的骨与软骨组织之间形成良好界面。 目的：模仿自然骨-软骨基质构建复合支架,以软骨细胞和骨髓间充质干细胞为种子细胞,体外观察复合组织的成软骨及成骨能力。 方法：制备明胶-硫酸软骨素-透明质酸及明胶-陶瓷化骨多孔复合支架,构建自然骨-软骨基质复合支架,复合兔软骨细胞与骨髓间充质干细胞,分未成骨诱导与成骨诱导两组培养,并进行MTT、糖胺多糖含量、碱性磷酸酶活性检测,以及苏木精-伊红染色检测。 结果与结论：未成骨诱导与成骨诱导两组骨髓间充质干细胞增殖及糖胺多糖含量差异无显著性意义。未成骨诱导组碱性磷酸酶活性缓慢上升,成骨诱导组诱导后碱性磷酸酶活性迅速上升,14 d时达到稳定状态。两组苏木精-伊红染色结果无明显区别,均已形成含有双层组织的类似骨-软骨样组织,其间可见未降解支架形态,但由于基质形成不完善及支架未完全降解,此种结构不成熟,细胞分布不均匀,支架内部可见散在无细胞区域。证实采用两种细胞与双层结构的支架经体外分层复合能够形成组织工程骨软骨复合组织。     

骨髓间充质干细胞在骨形态发生蛋白2/注射式硫酸钙载体上的成骨

背景：将生长因子复合到支架上构建复合材料可同时具备骨诱导和骨传导作用。 目的：观察骨形态发生蛋白2/注射式硫酸钙复合载体对大鼠骨髓间充质干细胞体外诱导成骨的影响。 方法：取生长状态良好的第2代SD大鼠骨髓间充质干细胞悬液,分3组培养：实验组将细胞悬液滴加到骨形态发生蛋白2/注射式硫酸钙复合材料表面,对照组在细胞悬液中加入骨形态发生蛋白2,空白对照组正常培养。 结果与结论：3组细胞随培养时间延长逐渐增多,实验组细胞数量最多,明显多于对照组及空白对照组(P < 0.05)。实验组培养不同时间点碱性磷酸酶活性高于对照组及空白对照组(P < 0.05)。体外实验显示骨形态发生蛋白2/注射式硫酸钙复合载体可促进骨髓间充质干细胞向成骨细胞分化。     

松质骨基质材料应用于牙周组织工程的可行性*☆

背景：松质骨基质材料具有骨诱导性和骨传导性双重特性,已被成功应用于骨再生及骨组织工程研究。 目的：分析松质骨基质材料的细胞相容性与毒性,探讨其应用于牙周组织工程的可行性。 方法：采用改良组织块法体外培养人牙周膜细胞,将其接种于松质骨基质三维支架上复合培养,采用细胞计数方法和扫描电镜观察人牙周膜细胞在松质骨基质支架上的附着、生长情况,并通过MTT测试法和碱性磷酸酶活性检测法观察松质骨基质浸提液对人牙周膜细胞增殖及功能表达的影响。 结果与结论：扫描电镜可见松质骨基质具有良好的多孔网状结构,人牙周膜细胞在松质骨基质上贴附紧密,生长旺盛,伸展充分,而人牙周膜细胞在不同浓度材料浸提液中的生长、增殖及碱性磷酸酶活性与阴性对照组相比差异无显著性意义。表明松质骨基质具有良好的三维空间结构和细胞相容性,且无细胞毒性,有望应用于牙周组织再生及牙周组织工程研究。     

Synergistic enhancement of ectopic bone formation by supplementation of freshly isolated marrow cells with purified MSC in collagen–chitosan hydrogel microbeads

ABSTRACT

Purpose: Bone marrow-derived mesenchymal stem cells (MSC) can differentiate osteogenic lineages, but their tissue regeneration ability is inconsistent. The bone marrow mononuclear cell (BMMC) fraction of adult bone marrow contains a variety of progenitor cells that may potentiate tissue regeneration. This study examined the utility of BMMC, both alone and in combination with purified MSC, as a cell source for bone regeneration. Methods: Fresh BMMC, culture-expanded MSC, and a combination of BMMC and MSC were encapsulated in collagen–chitosan hydrogel microbeads for pre-culture and minimally invasive delivery. Microbeads were cultured in growth medium for 3 days, and then in either growth or osteogenic medium for 17 days prior to subcutaneous injection in the rat dorsum. Results: MSC remained viable in microbeads over 17 days in pre-culture, while some of the BMMC fraction were nonviable. After 5 weeks of implantation, microCT and histology showed that supplementation of BMMC with MSC produced a strong synergistic effect on the volume of ectopic bone formation, compared to either cell source alone. Microbeads containing only fresh BMMC or only cultured MSC maintained in osteogenic medium resulted in more bone formation than their counterparts cultured in growth medium. Histological staining showed evidence of residual microbead matrix in undifferentiated samples and indications of more advanced tissue remodeling in differentiated samples. Conclusions: These data suggest that components of the BMMC fraction can act synergistically with predifferentiated MSC to potentiate ectopic bone formation. The microbead system may have utility in delivering desired cell populations in bone regeneration applications.     

The effect of bone marrow‐ and adipose tissue‐derived mesenchymal stem cell transplantation on myocardial remodelling in the rat model of ischaemic heart failure

This study aimed to investigate the effect of bone marrow‐ and adipose tissue‐derived mesenchymal stem cell (BM‐MSC and AD‐MSC respectively) transplantation on left ventricular function and infarct area (IA) in the rat model of ischaemic heart failure. In anaesthetized Wistar rats, the left coronary artery (LCA) was occluded for 40 min with subsequent reperfusion for 7 days. Seven days following surgery, the animals with LCA occlusion/reperfusion were randomized into three groups: (i) Controls received intramyocardial injection of vehicle at three different locations within the peri‐infarct zone, (ii) BM‐MSC: cells were injected in the same way as in previous group (10⁶), (iii) AD‐MSC: using the same protocol as used in the BM‐MSC group. In addition there was also a sham‐treated group that had no injection. Two weeks following MSC transplantation, the hearts were isolated and perfused according to the Langendorff method followed by 30‐min global ischaemia and 90‐min reperfusion. After this IA was determined histologically. During Langendorff perfusion initial and postischaemic LV functions were the same in all groups although LV pressure at the 10th minute of reperfusion was higher in the AD‐MSC group compared to controls. However, LV pressure during 30‐min global ischaemia was significantly higher in BM‐MSC as compared to controls and AD‐MSC. The sham treated animals showed the same results as those seen with BM‐MSC. Thus, BM‐MSC transplantation, in contrast to transplantation of AD‐MSC, resulted in better preservation of the LV ability to contract during ischaemia. Furthermore, IA was significantly smaller in BM‐MSC group as compared to the controls and the AD‐MSC groups. Thus this study has demonstrated that treatment with BM‐MSC both ameliorates LV function and reduces histological scar size.     

The effect of platelet-rich plasma on healing in critical-size long-bone defects

The role of platelet-rich plasma (PRP) as a promoter of bone healing remains controversial. The hypothesis investigated was that PRP improves bone healing of a critical-size diaphyseal radius defect in a rabbit model. The bone defect was filled with a high-surface ceramic scaffold, calcium-deficient hydroxyapatite (CDHA), with the addition of allogenic PRP, mesenchymal stem cells (MSC) or both. PRP yielded better bone formation than the empty CDHA scaffold as determined by both histology and micro-computer tomography (p<0.05) after 16 weeks, whereas no difference was observed on biomechanical testing. Similar behavior was found in samples with MSC; however, the combination of MSC and PRP did not further improve bone healing. Furthermore, the resorption of CDHA was improved by the addition of PRP, MSC and MSC/PRP, but there were no differences between the groups. The areas of bone formation were greater in areas adjacent to the bone resection areas and towards the intact ulna. In conclusion, PRP improves bone healing in a diaphyseal rabbit model on CDHA and the combination of CDHA. This study supports the allogenic use of PRP for bone healing as an off-the-shelf therapy.     

Effect of temporally patterned TNF-α delivery on in vitro osteogenic differentiation of mesenchymal stem cells cultured on biodegradable polymer scaffolds

Recent insight into the critical role of pro-inflammatory cytokines, particularly tumor necrosis factor-α (TNF-α), in bone regeneration has heralded a new direction in the design of tissue engineering constructs. Previous studies have demonstrated that continuous delivery of 50?ng/ml TNF-α to mesenchymal stem cells (MSCs) cultured on three-dimensional (3D) biodegradable electrospun poly(?-caprolactone) (PCL) microfiber meshes stimulates mineralized matrix deposition, a marker of osteogenic differentiation. Since TNF-α exhibits a biphasic pattern of expression following bone fracture in vivo, this study aimed to investigate the effects of temporal patterns of TNF-α delivery on in vitro osteogenic differentiation of MSCs cultured on 3D electrospun PCL scaffolds. MSCs were cultured for 16?days and exposed to continuous, early, intermediate, or late TNF-α delivery. To further elucidate the effects of TNF-α on osteogenic differentiation, the study design included MSCs precultured both in the presence and absence of typically required osteogenic supplement dexamethasone. Mineralized matrix deposition was not observed in constructs with dexamethasone-naïve MSCs, suggesting that TNF-α is not sufficient to trigger in vitro osteogenic differentiation of MSCs. For MSCs precultured with dexamethasone, TNF-α suppressed alkaline phosphatase activity, an early marker of osteogenic differentiation, and stimulated mineralized matrix deposition, a late stage marker of MSC osteogenic differentiation. By elucidating the impact of temporal variations in TNF-α delivery on MSC osteogenic differentiation, our results offer insight into the regenerative mechanism of TNF-α and provide the design parameters for a novel tissue engineering strategy that rationally controls TNF-α signaling to stimulate bone regeneration.     

Enhancement of osteogenesis by concanavalin A in human bone marrow mesenchymal stem cell cultures

This study investigates concanavalin A (ConA) as a novel factor that may enhance osteogenesis of mesenchymal stem cells (MSCs) in vitro. Various factors, such as cytokine bone morphogenetic protein-2 (BMP-2), have been studied for their possible promotion of MSC osteogenesis in vivo and in vitro. However, the factor that might be safer, more effective, and less expensive than these has not been determined. We therefore cultured human MSCs in osteogenic medium in the presence or absence of ConA, and used calcium assays to compare the effects of ConA and BMP-2 on MSC calcification. We also used enzyme-linked immunosorbent assay (ELISA) and quantitative polymerase chain reaction (PCR) to evaluate the expression levels of bone-specific markers. ConA and BMP-2 enhanced calcification with comparable effectiveness. The combination of ConA and BMP-2 further enhanced calcification slightly but significantly. ConA also increased osteocalcin and BMP-2 protein levels in MSC culture medium. Furthermore, ConA increased osteocalcin, RUNX2, BMP-2, BMP-4, and BMP-6 mRNA expression levels. However, the gene expression pattern of ConA-stimulated MSCs was different from that of MSCs stimulated by BMP-2. Together, these results suggest that ConA and BMP-2 enhance MSC osteogenesis via different pathways. ConA-induced bone formation in MSC cultures may be useful in regenerative medicine or tissue engineering in clinical studies, as well as in basic research on bone formation.     

Bone tissue engineering with human mesenchymal stem cell sheets constructed using magnetite nanoparticles and magnetic force

An in vitro reconstruction of three-dimensional (3D) tissues without the use of scaffolds may be an alternative strategy for tissue engineering. We have developed a novel tissue engineering strategy, termed magnetic force-based tissue engineering (Mag-TE), in which magnetite cationic liposomes (MCLs) with a positive charge at the liposomal surface, and magnetic force were used to construct 3D tissue without scaffolds. In this study, human mesenchymal stem cells (MSCs) magnetically labeled with MCLs were seeded onto an ultra-low attachment culture surface, and a magnet (4000 G) was placed on the reverse side. The MSCs formed multilayered sheet-like structures after a 24-h culture period. MSCs in the sheets constructed by Mag-TE maintained an in vitro ability to differentiate into osteoblasts, adipocytes, or chondrocytes after a 21-day culture period using each induction medium. Using an electromagnet, MSC sheets constructed by Mag-TE were harvested and transplanted into the bone defect in the crania of nude rats. Histological observation revealed that new bone surrounded by osteoblast-like cells was formed in the defect area 14 days after transplantation with MSC sheets, whereas no bone formation was observed in control rats without the transplant. These results indicated that Mag-TE could be used for the transplantation of MSC sheets using magnetite nanoparticles and magnetic force, providing novel methodology for bone tissue engineering.     

胎儿骨髓间充质干细胞的分离培养及表面标志的检测

目的 建立胎儿骨髓间充质干细胞（mesenchymal stem cells,MSC)的分离培养方法，并对其表面标志进行检测。方法 采用体外细胞培养技术，分离培养胎儿骨髓MSC，用流式细胞术对其进行鉴定，并研究其增殖及生长特征。结果 流式细胞术证明，MSC具有间质细胞的特征。原代及传代培养显示，胎儿骨髓MSC具有活跃增殖的能力。结论 胎儿骨髓MSC作为组织工程重建的种子细胞具有较强的可行性。     

The effect of bioactive glass content on synthesis and bioactivity of composite poly (lactic-co-glycolic acid)/bioactive glass substrate for tissue engineering

Tissue engineering offers a promising new approach to bone tissue grafting. One material that has received attention in this regard is the polymer poly (lactic-co-glycolic acid) (PLGA). It has the advantage of controllable bioresorption and ease of processing. Another material of interest is bioactive glass (BG), which shows the ability to stimulate osteoblastic differentiation of osteoprogenitor cells. In this study, we reported on the optimal synthesis parameters and the kinetics of formation of calcium phosphate (Ca-P) phase at the surface of PLGA/BG composites. The formation of calcium phosphate layer was confirmed using scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDXA). PLGA-30%BG microspheres based porous scaffolds for bone tissue engineering were examined for their ability to promote osteogenesis of marrow stromal cells (MSC). This porous scaffold supported both MSC proliferation and promoted MSC differentiation into cells expressing the osteoblast phenotype. It therefore demonstrates significant potential as a bone replacement material.     

Influence of platelet-rich plasma on osteogenic differentiation of mesenchymal stem cells and ectopic bone formation in calcium phosphate ceramics

Platelet-rich plasma (PRP) contains a mixture of growth factors that play an important role in wound and fracture healing. While PRP enhanced bone formation by autogenous cancellous bone grafts, its influence in combination with different bone substitutes remained unknown. This study evaluated the effect of PRP on osteogenic differentiation and ectopic bone formation of human mesenchymal stem cells (MSC) in distinct resorbable calcium phosphate ceramics. Calcium-deficient hydroxyapatite (CDHA) blocks with a large specific surface area (48 m2/g) and beta-tricalcium phosphate (beta-TCP) with a low specific surface area (<0.5 m2/g) were loaded with 2 x 10(5) bone marrow-derived MSC. Half of the specimens were treated with 5-fold concentrated PRP. Biocomposites were implanted subcutaneously into SCID mice or kept under osteogenic culture conditions for 2 weeks before implantation. The addition of PRP increased the specific alkaline phosphatase (ALP) activity (p = 0.012) in undifferentiated MSC/CDHA composites but not in MSC/beta-TCP composites. Osteogenic preinduction was ineffective for CDHA and reduced ALP activity of beta-TCP composites significantly at explantation. Ectopic bone formation was stronger in MSC/CDHA (7/32) compared to MSC/beta-TCP (2/30) composites, but no influence of PRP was evident. In conclusion, the effect of PRP depended on the type of ceramic and the differentiation status of the MSC, and enhanced ALP activity of MSC on the high surface scaffold CDHA only, but PRP did not improve osteogenesis in our setting.