软骨素酶ABC处理化学去细胞异体神经后的形态学观察

[目的]观察软骨素酶ABC处理化学去细胞异体神经后,硫酸软骨素蛋白多糖(CSPG)去除效果以及对活性成分层粘蛋白(Laminin)的影响.[方法]取12根新鲜猪坐骨神经,每段长60 mm,应用7%脱氧胆酸钠与7%Triton X-100制备化学去细胞异体神经后,随机分为两组.实验组(n=6):软骨素酶ABC处理组,将6根去细胞异体神经浸泡在包软骨素酶ABC(2 U/ml)的PBS(pH 7.4);对照组(n=6)为PBS液浸泡.两组处理时间均为16 h 37℃水浴.分别对两组神经行HE染色以及CSPG、Laminin免疫荧光染色观察.[结果]实验组与对照组HE纵切片均未能观察到细胞,红染的神经基底膜呈波浪状纵形排列,轴突消失而形成管柱状空隙;对照中CSPG免疫荧光染色阳性,经软骨素酶ABC处理后CSPG免疫荧光染色阴性;而实验组和对照组基底膜管成分层粘蛋白免疫荧光染色显示为阳性.[结论]经软骨素酶ABC处理的去细胞异体神经特异性降解了不利于神经生长的成分CSPG,而对去细胞神经中促神经生长成分Laminin无影响,可能是修复周围神经缺损的良好的移植物.     

去细胞猪主动脉瓣膜基质支架材料体外降解的初步观察

目的 观察去细胞猪主动脉瓣膜基质支架材料的体外降解方式和过程。方法 将制备好的去细胞猪主动脉瓣膜基质支架材料90片随机分为3组，胶原酶组、弹性蛋白酶组和水解对照组，每组30片，分别用0．05mg／ml胶原酶Ⅰ、0．05mg／ml弹性蛋白酶和磷酸盐缓冲液（PBS）作为降解液在体外处理去细胞猪主动脉瓣膜。于处理后第3、6、9、12、15和30d从每组取出5个平行样本观察瓣膜组织形态学改变，测定降解失重率、降解液中蛋白含量、羟脯氨酸含量等指标。结果 胶原酶组和弹性蛋白酶组去细胞瓣膜基质支架材料均随降解时间延长逐渐变得菲薄、韧性差、组织疏松、纤维网孔变大、断裂，降解液外观变浑浊，瓣膜失重率增加，降解液蛋白含量和羟脯氨酸含量增加（P〈0．01）；胶原酶组较弹性蛋白酶组对去细胞猪主动脉瓣膜基质支架材料的降解作用强。结论 胶原酶和弹性蛋白酶对去细胞猪主动脉瓣膜基质支架材料均有降解作用，且前者的降解作用强于后者。     

异种骨移植材料制备及其骨诱导活性实验研究

目的 采用酶处理法去除猪骨组织中的主要异种抗原--α-半乳糖抗原(α-Gal),探讨不同处理方式对其力学性能和骨诱导活性的影响.方法 取新鲜猪髂骨用α-半乳糖苷酶处理去除α-Gal,冷冻干燥后辐照灭菌.根据处理方法不同,将猪髂骨分为:A组新鲜骨、B组去抗原骨、C组冻干去抗原骨及D组冻干辐照去抗原骨.取B组骨扫描电镜观察,Smile View软件测量骨髓腔大小;采用ELISA法检测A、B及D组骨块α-Gal含量:检测A、B、C及D组力学性能;将去抗原脱矿骨(实验组)及脱矿骨(对照组),植入Wistar大鼠股部肌袋,于术后3、4、5、6周取出植入骨行组织学观察及ALP活性检测.结果 制备的B组骨呈三维网状结构,与人松质骨类似,骨髓腔大小为150～600μm.A、B、D组α-Gal吸光度值分别为0.358±0.027、0.191±0.011和0.190±0.009,组间差异有统计学意义(P<0.05).A、B、C、D组间力学性能比较差异无统计学意义(P>0.05).实验组植入3周,骨内长入的间充质细胞转变成软骨细胞并开始分泌软骨基质,4周骨内形成软骨组织,6周骨边缘成骨活跃,形成类骨质,骨内可见成熟软骨组织:对照组植入3～6周显示植入骨吸收,未见成骨迹象.实验组植入3～6周的ALP活性均显著高于对照组,差异有统计学意义(P<0.05).结论 酶处理法能有效去除猪骨组织中的主要异种抗原,保留了其力学性能与骨诱导活性,有望成为一种骨移植替代材料.     

组织工程角膜生物材料载体制备的比较性研究

目的 比较用不同的方法脱细胞处理异种（猪）角膜基质制备组织工程角膜支架材料，并对其生物相容性进行研究。方法 成年York猪角膜基质材料，以Triton联合0．25％胰酶，处理30min 3h为材料1；Triton联合DNA—RNA酶，处理8～14h为材料2；Triton联合0．25％胰酶、DNA—RNA酶，处理3～5h为材料3。3种材料用无水氯化钙脱水干燥保存。在材料上接种兔角膜基质成纤维细胞，观察细胞生长情况。新西兰大白兔24只，随机分为3组，每组8只。右眼为实验眼，左眼为空白对照眼。将材料植入兔眼角膜基质层中，术后每日裂隙灯检查术眼；1、4、8和12周分别随机取2只兔眼角膜作HE染色，观察材料的生物相容性。结果 材料1、2细胞脱出不完全，处理最佳时间分别是2hN10～12h，角膜基质网状间隙无明显增大；接种兔角膜基质成纤维细胞后，3～4d细胞死亡；植入兔角膜基质中有明显的免疫排斥反应。材料3脱出细胞完全，其脱细胞处理的最佳时间为4h，角膜基质纤维结构无破坏，呈三维网状结构，网状间隙明显增大；接种兔角膜基质成纤维细胞后，细胞在材料上贴附生长良好；将其植入兔角膜基质中无炎性及排斥反应，可逐渐降解吸收，有良好的生物相容性。结论 Triton联合0．25％胰酶、DNA—RNA酶法处理的异种（猪）角膜基质具有良好的生物相容性，可作为一种组织工程角膜的支架材料。     

胶原-透明质酸支架的制备及其与软骨细胞复合培养的实验研究

目的制备胶原-透明质酸支架,评价其与兔髁状突软骨细胞的生物相容性,探讨其应用于关节软骨组织工程的可行性。方法冷冻干燥法制备胶原-透明质酸复合多孔海绵支架材料,将其与碳化二亚胺[1-ethyl-3-（3-dimethyl aminopropyl）carbodiimide,EDC]进行化学交联。分别采用体积法和体外酶解实验测定支架材料孔隙率和降解率,扫描电镜观察交联前后支架材料的形态变化。取3周龄新西兰兔髁状突软骨细胞,体外培养5d后,甲苯胺蓝染色,倒置相差显微镜下观察行细胞鉴定。取消化后第2代软骨细胞接种至支架材料复合培养,倒置相差显微镜下观察细胞生长情况。复合培养1、3、5、7和10d后,PBS液清洗3次,置入24孔板并以0.25%胰酶和0.1%EDTA消化细胞,采集细胞进行细胞计数并绘制细胞生长曲线。另取部分样本继续培养5d,行组织学和扫描电镜观察。结果胶原-透明质酸支架材料经化学交联后,具有合适的三维多孔结构,孔隙率为83.7%,孔径100-120μm;交联后抗酶解能力显著增加。髁状突软骨细胞在其表面和内部贴附良好,形成细胞-材料复合体,细胞增殖实验显示,复合培养1d,材料中细胞数为3.7×104/支架,10d后增至8.2×104/支架。电镜观察见细胞周围有基质分泌。结论EDC交联后的胶原-透明质酸支架具有良好空间结构和生物相容性,可作为支架材料用于髁状突软骨组织工程的研究。     

门静脉回流、胰液肠内引流术式猪全胰十二指肠移植模型的建立

目的建立稳定的、符合生理的门静脉回流、空肠内引流术式猪全胰十二指肠移植模型。方法40头四川本地杂种猪分为供、受体两组(n=20)。采用UW液低温灌注的方法，整块切取供体全胰十二指肠，保留腹主动脉Carrel片和门静脉。UW液保存、修整后的胰腺十二指肠移植物用髂血管延长的动脉与供体腹主动脉段端-侧吻合；门静脉与供体肠系膜上静脉端-侧吻合；十二指肠与供体空肠侧-侧吻合。结果共完成猪全胰十二指肠移植手术20例。胰腺移植术后1例因麻醉过深，呼吸抑制而术后未能复苏；1例移植胰腺血栓形成、血管栓塞；另1例死于肠瘘导致的腹腔感染。17例术后第2天检测外周血血糖正常。结论猪全胰十二指肠移植门静脉回流、空肠内引流术式大动物模型稳定、可靠。     

高黏度温敏性几丁聚糖水凝胶的制备及特性初步研究

目的 改进制备工艺，提高几丁聚糖，甘油磷酸钠水凝胶（chitosan／glycerol phosphate。C／GP）的黏度，以期拓展其应用范围。方法采用改进的消毒方法，即将几丁聚糖单独进行高压蒸汽消毒，制备高黏度温敏性C／GP（highviscousC／GP,HV-C／GP）。并采用常规方法制备C／GP。Gemini流变仪动态检测HV-C／GP、C／GP流变学变化，评估黏度提高以后材料的初始黏度、胶凝温度和胶凝时间变化。将凝胶化的两种材料，放入PBS液中，于0、1、2、5、10和25d取出，干燥称重，计算失重率，比较两种材料的体外降解情况。采用扫描电镜观察两种材料的超微结构。结果脱乙酰度91％的C／GP初始黏度为1．81Pas，而HV-C／GP为17．24Pas，后者较前者提高了近10倍。C／GP的胶凝温度为37℃，HV-C／GP为34℃：在胶凝温度下，两者的胶凝时间约为5min。0．5mLHV-C／GP和C／GP凝胶化后第1天，失重率分别约为72．5％和55．4％，此后质量逐渐降低，至第25天分别为90．8％和78．2％。扫描电镜下两种材料均可以观察到多孔网络结构，C／GP孔径为50～100μm，HV-C／GP孔径为30～50μm，后者较前者明显缩小。结论通过改进消毒方法制备的HV-C／GP黏度明显提高，但温敏性变化不大；降解时间有所延长；扫描电镜观察可见多孔网络状结构，且孔径减小。     

比较不同处理方法对脱细胞真皮渗透性的影响

目的比较不同处理方法对猪脱细胞真皮渗透性的影响。方法对猪脱细胞真皮分别进行冷冻干燥、机械打孔、戊二醛交联三种处理，比较处理前后孔隙率的变化，并将100出浓度为1&#215;10^6／ml的成纤维细胞悬液分别接种于无处理脱细胞真皮基质（ADM）及经3种处理后ADM上，于1、3、5、7d用MTT法测定其OD值，每组各取接种1周后的复合皮行HE染色观察。结果猪脱细胞真皮的平均孔隙率为65．61％，冷冻干燥后为67．85％。机械打孔后为71．37％，经戊二醛交联后为66．11％。MTT试验的生长曲线图显示，成纤维细胞在打孔后ADM上黏附增殖优于其他组。切片HE染色显示，经打孔处理后，细胞可部分渗透至ADM内，其他组细胞仅在其表面爬行且膜片不完整。结论机械打孔法能提高猪脱细胞真皮的渗透性，可用于组织工程皮肤的构建。     

纳米结构PCL—b—PLLA材料特性及其与犬软骨细胞的生物相容性研究

目的探讨具有纳米结构的聚己内酯／左旋聚乳酸共聚物（PCL—b—PLIJA）作为半月板组织工程支架的可行性，及其与犬软骨细胞的体外生物相容性。方法开环聚合制备PCL-b-PLLA，液-液相分离技术制备纳米结构PCL—b—PLLA支架，固-液相分离技术制备PCL—b—PLLA支架，扫描电镜（SEM）观察材料结构；测定纳米结构支架体外降解率及力学强度。分离培养犬软骨细胞，取第3代软骨细胞接种于纳米结构PCL—b—PLIA（实验组）、PCL—b—PLLA（对照组）支架材料上进行三维培养6d，SEM观察软骨细胞的形态、粘附、生长状况；细胞支架复合培养3、6、12d后，Hoechst33258荧光法检测复合物中细胞DNA含量、BCA法测定蛋白质含量。结果实验组支架材料相对分子量150kD，压缩强度为72．6KPa，孔隙率为93％。SEM示实验组支架表面为多孔状，孔壁为纤维网状连接。其降解率起初始较慢，8周后降解速率明显加快。软骨细胞在实验组支架上粘附、增殖优于对照组。随时间延长细胞在支架材料上DNA和蛋白质含量逐渐增加，实验组DNA和蛋白质含量均明显高于对照组（P〈0．01，P〈0．05）。结论具有纳米结构的PCL-b—PILA支架具有良好的生物力学性能及可降解性，可显著促进细胞粘附、增殖及合成代谢，有望成为一种较为理想的半月板组织工程支架材料。     

表皮细胞悬液自体移植治疗节段型白癜风

目的：为节段型白癜风的治疗建立一种更为简便，有效的手段。方法：采用滚轴取皮刀切取表皮，经胰酶消化后制备表皮细胞悬液，采用水疱内注入法自体移植治疗节段型白癜风。结果：所治患者均取得了较为满意的临床疗效，平均色素恢复率大于80％。结论：表皮细胞悬液自体移植为白癜风的治疗又提供了一种简易而有效的方法。     

新型可降解人工泪小管的制备与表征

目的研制一种可生物降解的胶原．壳聚糖．聚乙烯醇[poly（vinyl alcoh01），PVA]复合人工泪小管，用于治疗因泪道阻塞导致的溢泪症。方法按照一定比例均匀混合胶原、壳聚糖、医用PVA溶液，通过反复的冻融过程使其形成弹性凝胶，再依次经过清洗、造孔、脱水、剪切后即得T1、T2和T3组的可降解人工泪小管。光镜下观察表面形貌和测量内、外直径。扫描电镜观察T2组人工泪小管凝胶态和干态的断口形貌，以及是否存在相分离现象。通过吸水溶胀性能测试计算3组人工泪小管的吸水率和膨胀率。采用体外降解实验初步观察3组人工泪小管的降解情况。结果通过物理交联成胶的方法成功制备出内径0．5～0．7mm，外径0．9～1．5mm，长度≥20mm的胶原-壳聚糖-PVA复合人工泪小管。扫描电镜观察到液氮脆断的人工泪小管内部成分分布均匀，内外壁表面平整，冷冻干燥的人工泪小管断口呈凝胶态的互穿网络结构。3组不同成分的人工泪小管在PBS溶液中浸泡30min后均快速吸水溶胀，外径扩大100％～120％，内径扩大20％～30％，并且随胶原含量增高，溶胀速度增快，平衡溶胀率增大。3组人工泪小管在37℃含2mg／mL溶菌酶的PBS液中浸泡1个月后，表面有部分细小絮状物，管口开裂，管壁变薄，透明度增加。在70℃PBS溶液中加速降解2d后，该小管成白色糊状。结论制备的新型可降解人工泪小管具有良好的力学性能和吸水溶胀性，便于手术操作，可支撑泪道，利于泪液的流诵，防止泪小管粘连，有望成为一种治疗泪道阻塞的新材料。     

In vitro elution of antibiotic from antibiotic-impregnated biodegradable calcium alginate wound dressing.

OBJECTIVE: The authors investigated the calcium alginate dressing as a drug-delivery system for the treatment of various surgical infections. METHODS: Cytotoxicity of the calcium alginate dressing to fibroblasts and HeLa cells was evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MITT) colorimetric assay. The calcium alginate dressing was mixed with vancomycin, and lyophilized or not lyophilized to form two types of antibiotic dressings. The antibiotic dressings were placed in 2 mL of phosphate buffered saline (PBS) or in PBS containing 0.01% calcium ions, and incubated at 37 degrees C. The PBS was changed daily, and the removed solutions were stored at -70 degrees C until the antibiotic concentration in each sample was determined by high performance liquid chromatography assay. RESULTS: The results suggested that the antibiotic dressings present no obvious toxic risk to their use as a drug-delivery system. The concentration of vancomycin in each sample was well above the breakpoint sensitivity concentration (the antibiotic concentration at the transition point between bacterial kill. ing and resistance to the antibiotic) for more than 14 days. The release was most marked during the first 48 hours. The concentration of calcium ions in PBS and the lyophilization of the manufacture process of antibiotic dressings prolonged the antibiotic diffusion duration. The diameter of the sample inhibition zone ranged from 10 to 11 mm, and the relative activity of vancomycin ranged from 62.88% to 92.18%. CONCLUSION: All antibiotic dressings released bactericidal concentrations of the antibiotics in vitro for the period of time needed to treat surgical infections. This study offers a convenient method to meet the specific antibiotic requirement for different patients.     

组织工程皮肤种子细胞的同期快速分离

目的 寻找一种快速可行的同期分离组织工程皮肤种子细胞——表皮细胞及成纤维细胞的方法。方法 取手术切除包皮，利用Ⅰ型胶原酶结合胰蛋白酶消化法，同期分离表皮细胞及成纤维细胞，观察细胞形态。对表皮细胞及表皮干细胞行PAN—FITC、K19-FITC荧光免疫染色及K19流式细胞仪鉴定；对成纤维细胞行波形蛋白FITC免疫荧光鉴定。并分别对两种细胞培养7d，观察其生长情况。结果 应用Ⅰ型胶原酶结合胰蛋白酶，在3h内快速分离得到表皮细胞及成纤维细胞，免疫荧光染色表皮细胞PAN—FITC染色均为阳性、K19-FITC染色部分阳性，流式细胞仪鉴定其K19阳性表达的细胞接近17％。表皮细胞培养48h开始呈克隆样增长，至7d生长停滞，向终末的角细胞分化。成纤维细胞体外培养7d可扩增100倍，波形蛋白FITC免疫荧光染色呈阳性。结论 利用胶原酶结合胰蛋白酶消化法可在3h内同期分离到用于构建复合型组织工程皮肤的种子细胞，为复合组织工程皮肤的快速构建提供了可能。     

Prolonged survival of murine thyroid allografts after 7 days of hyperbaric organ culture in the UW preservation solution at hypothermia

Organ culture of murine thyroid allografts in hyperbaric oxygen (95% O2 at 25 psi, 37 degrees C) for 48 hr, results in prolonged allograft survival. Endocrine tissues can be cultured at 37 degrees C--however, this method may not be applicable to vascularized organs at normothermia. The aim of this study was to apply hyperbaric oxygen culture (HOC) under organ preservation conditions (hypothermia, UW solution) that have been shown to be successful in clinical organ transplantation. B10BR/SGSNJ murine thyroid lobes were transplanted beneath the kidney capsule of C57BL/10J recipients. Thyroids were cultured in Eagle's MEM at 37 degrees C (controls) and at 5 degrees C, under hyperbaric conditions (95% O2:5% CO2, 25 psi). Alternatively, thyroids were cultured in UW solution (+/- allopurinol/GSH) at 5 degrees C, for up to 7 days. Graft survival was determined 21 days posttransplant by 125I uptake and by histology. In Eagle's MEM, HOC at 37 degrees C/48 hr and 5 degrees C/7 days, resulted in 93% and 20% allograft survivals, respectively. In UW solution (- allopurinol/glutathione [GSH]), HOC at 5 degrees C/7 days resulted in 83% allograft survival: immunoperoxidase staining showed a decrease of MHC class I alloantigen expression. Oxygen free radical scavenger (allopurinol/GSH) addition to the UW solution diminished this effect and suggested an oxygen free radical-mediated mechanism in immunoalteration. These results demonstrate that HOC for 7 days reduced the antigenicity and immunogenicity of murine thyroid grafts under conditions that simulate organ preservation. Hypothermic hyperbaric oxygen culture conditions require testing in a higher animal species and in vascularized grafts to determine if this method can be applied to whole-organ transplantation.     

曲拉通X-100对制备猪胸主动脉脱细胞血管基质影响的实验研究

目的为将内皮细胞和平滑肌细胞种植于脱细胞血管基质(Acellular Tissue Matrix,ACTM)上形成组织工程化血管提供实验依据.方法用曲拉通(Triton)X-100等试剂制备猪胸主动脉ACTM,并寻找曲拉通X-100的最佳浓度.取家猪的新鲜去除外膜胸主动脉56根,随机分成7组,每组分别浸入不同浓度的曲拉通 X-100中作用144 h～240 h.标本作HE弹力纤维染色,大体、光镜及透射电镜观察.结果经上述试剂处理后,光镜及透射电镜检查显示,制备出的猪胸主动脉脱细胞血管基质由胶原纤维、弹力纤维和某些不可溶的、变性细胞器构成.曲拉通 X-100最佳浓度为1%.时间为176.25 h±5.5 h.结论本方法可成功制备猪胸主动脉ACTM,1%曲拉通 X-100是制备血管ACTM的良好试剂.     

Comparative investigation of alloplastic materials for hernia repair with improved methodology

Background: A variety of alloplastic materials are used for hernia repair. We discuss the long-term stability and possible shrinkage of these materials. In the past, measurement of pore sizes was used to study the physical properties of alloplastic meshes. The aim of this study was to evaluate the measurement of pore sizes with regard to its correlation to possible mesh alteration. Methods: The water absorption of different polypropylene (PP) and polyester (PE) mesh materials under defined conditions was studied. For shrinkage studies, meshes were stored in formaldehyde, distilled water, saline solution, trypsin solution, urea solution, and hydrogen peroxide. The measurement of the relation between material and pore was evaluated to investigate the potential shrinking and enlargement processes. This material–pore index (MPI) before as well as 1, 7, and 14 days after incubation was measured. Results: In comparison to measuring single pore sizes, MPI determination is the more efficient method to evaluate the possible shrinking or enlargement processes of alloplastic materials. With this technique, incorrect determination of pore sizes due to the dynamic textile structure of meshes and to shrinkage or enlargement, is excluded. All tested alloplastic materials showed an insignificant increase in water absorption under the condition of rehydration up to 0.4%. We did not observe variances in the material in shrinking or enlargement. Conclusions: MPI was found to be more reliable than measuring single pores to investigate possible external influences on polymer materials. Biomaterials such as PP and PE proved to be absolutely inert under various in vitro conditions.     

Antimicrobial endodontic compounds do not modulate alkylation-induced genotoxicity and oxidative stress in vitro.

OBJECTIVE: To investigate if formocresol, paramonochlorophenol, or calcium hydroxide modulate the genotoxic effects induced by the oxidatively damaging agent hydrogen peroxide (H2O2) or the alkylating agent methyl methanesulfonate (MMS) in vitro by using single cell gel (comet) assay. STUDY DESIGN: Chinese hamster ovary (CHO) cells in culture were exposed directly to formocresol, paramonochlorophenol, or calcium hydroxide (adjusted to 100 microg/mL) for 1 hour at 37 degrees C. Subsequently the cultures were incubated with increasing concentrations (0-10 micromol/L) of MMS in phosphate-buffered solution (PBS) for 15 minutes at 37 degrees C or of H2O2 at increasing concentrations (0-100 micromol/L) in distilled water for 5 minutes on ice. The negative control cells were treated with PBS for 1 hour at 37 degrees C. The parameter from the comet assay (tail moment) was assessed by the Kruskal-Wallis nonparametric test followed by a post hoc analysis (Dunn test). RESULTS: Clear concentration-related effects were observed for the genotoxin-exposed CHO cells. Increase of MMS-induced DNA damage was not significantly altered by the presence of the compounds tested. Similarly, no significant changes were observed when hydrogen peroxide was used with the endodontic compounds evaluated. CONCLUSION: Formocresol, paramonochlorophenol, and calcium hydroxide are not able to modulate alkylation-induced genotoxicity or oxidative DNA damage as depicted by the single cell gel (comet) assay.     

An articulated antibiotic spacer used for infected total knee arthroplasty: a comparative in vitro elution study of Simplex and Palacos bone cements.

For the staged management of infected total knee arthroplasty (TKA), antibiotic laden polymethylmethacrylate (PMMA) spacers have been recommended. Antibiotic-impregnated PMMA spacers target drug delivery, achieving high local levels while limiting the potential for host toxicity associated with parenteral antimicrobial therapy. This study examined the elution characteristics of an articulating PMMA TKA spacer that has been useful clinically. Tobramycin and vancomycin are both active against many organisms leading to joint infections. We used various combined antibiotic concentrations (maintaining a relative ratio of 55% tobramycin to 45% vancomycin w/w), and then assayed the elution profile of the TKA spacer in vitro. Additionally, the elution qualities of two brands of bone cement, Simplex and Palacos, were compared. Briefly, three groups of PMMA spacers, impregnated with different antibiotic loads, were fashioned from a mold replicating a femoral TKA component. The entire spacer surface area was immersed in sterile phosphate buffered saline (PBS) in a 1:6 ratio of grams of cement to milliliters of PBS and incubated at 37 degrees C for 24 h. After 24 h, aliquot eluates were taken, the PBS discarded, and replaced with fresh, sterile PBS. PBS was changed daily and an aliquot was taken at least weekly for nine weeks. Eluate samples were stored at -70 degrees C until assayed. Each spacer eluate sample's antibiotic concentration was determined by disc diffusion bioassay against Bacillus subtilis. Mean zone inhibition diameters were extrapolated from the standard curve to yield micrograms per milliliter of antibiotic in PBS. In all groups the Palacos spacers demonstrated higher elution levels, above the MIC for the organism used, for a longer period of time than those made with Simplex. Based on the observed elution profiles, antibiotic-impregnated Palacos bone cement may offer a more effective vehicle for local drug delivery during staged treatment of infected TKA.     

Curcumin has potent liver preservation properties in an isolated perfusion model

BACKGROUND: Curcumin has profound antioxidant and anti-inflammatory properties. This research assessed the effect of curcumin on liver preservation. METHODS: Sprague-Dawley rat livers were flushed with different preservation solutions [Euro-Collins solution (EC), phosphate buffer saline (PBS), University of Wisconsin solution (UW)] with or without curcumin (25-200 microM) and stored at 4 degrees C for 24-48 hours. Livers were then perfused for 120 minutes via the portal vein with oxygenated Krebs-Henseleit bicarbonate buffer solution at a pressure of 18 cm H2O in a perfusion apparatus. The livers in the normal (NL) group were flushed with EC, PBS, or UW, then immediately perfused (zero preservation time). RESULTS: We found that curcumin at 100 microM concentration had the optimal preservation characteristics. Portal flow rates and bile production were significantly higher and liver enzymes (alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase) were significantly lower in the EC+C livers and PBS+C livers than in the EC or PBS with optimum concentration of 100 microM of curcumin. Comparing UW+C vs. UW livers, at 24 hours there was no difference in these parameters; however, at 36 hours and 48 hours, portal flow rates and bile production were significantly higher in UW+C livers. CONCLUSIONS: We found that curcumin has inherent organ preservation quality as it enhanced liver preservation in PBS. In addition, curcumin enhanced the preservation quality of EC and UW solutions, thereby extending the preservation time while maintaining the organ quality.     

Comparison of meniscal allograft transplantation techniques using a preclinical canine model

Meniscal allograft transplantation (MAT) can be a safe, effective treatment for meniscal deficiency resulting in knee dysfunction, leading to osteoarthritis (OA) without proper treatment with 5‐year functional success rates (75%‐90%). While different grafts and techniques have generally proven safe and effective, complications include shrinkage, extrusion, progression of joint pathology, and failure. The objective of this study was to assess the functional outcomes after MAT using three different clinically‐relevant methods in a preclinical canine model. The study was designed to test the hypothesis that fresh meniscal‐osteochondral allograft transplantation would be associated with significantly better function and joint health compared with fresh‐viable or fresh‐frozen meniscus‐only allograft transplantations. Three months after meniscal release to induce meniscus‐deficient medial compartment disease, research hounds (n = 12) underwent MAT using meniscus allografts harvested from matched dogs. Three MAT conditions (n = 4 each) were compared: frozen meniscus–fresh‐frozen meniscal allograft with menisco‐capsular suture repair; fresh meniscus–fresh viable meniscal allograft (Missouri Osteochondral Preservation System (MOPS)‐preservation for 30 days) with menisco‐tibial ligament repair; fresh menisco‐tibial–fresh, viable meniscal‐tibial‐osteochondral allografts (MOPS‐preservation for 30 days) with menisco‐tibial ligament preservation and autogenous bone marrow aspirate concentrate on OCA bone. Assessment was performed up to 6 months after MAT. Pain, comfortable range of motion, imaging, and arthroscopic scores as well histological and cell viability findings were superior (P < .05) for the fresh menisco‐tibial group compared with the two other groups. Novel meniscal preservation and implantation techniques with fresh, MOPS‐preserved, viable meniscal‐osteochondral allografts with menisco‐tibial ligament preservation appears to be safe and effective for restoring knee function and joint health in this preclinical model. This has the potential to significantly improve outcomes after MAT.