骨科假体表面涂层技术现状

由植入物界面处的相互作用可能引起无菌性松动和假体周围感染。而无菌性松动和假体周围感染仍然是一个难以治疗的问题,并且最终可能导致假体植入失败,引起严重后果。理想的植入物应能促进骨整合,防止细菌粘附,减少细菌感染。骨科植入技术主要基于生物材料的开发和使用,随着材料科学和细胞生物学的发展,已可以用新的植入物表面涂层的进展来解决这些问题。本文回顾总结了时下骨科常见的假体涂层设计和相关问题,以期为进一步研究提供借鉴。     

壳聚糖-HCG缓释制剂对鱼类生殖内分泌机能的影响

以壳聚糖为原料制备壳聚糖-HCG缓释制剂,进行激素埋植实验,间隔一定时间检测雌和雄鱼性腺发育、血清主要性激素含量和繁殖内分泌相关基因表达特征。结果表明:在埋植壳聚糖-HCG缓释激素后,雌鱼性成熟系数（GSI）、血清睾酮（T）水平、血清雌二醇（E2）水平在630d内较对照组效果明显;雄鱼GSI仅在第6天显著高于对照组,血清T水平在第2、第14天高于对照组。血清E2水平在实验期间与对照组无显著差异。RT-PCR结果显示:性腺型P450芳香化酶（CYP19A）在性腺中表达丰富,心脏中最少。雌鱼性腺P450芳香化酶（CYP19A）基因mRNA相对表达量在第2、第6天显著高于对照组,雄鱼在第6天显著高于对照,雌鱼性腺雌激素受体（ER）基因mRNA相对表达量在1430d显著高于对照组,雄鱼在第6至第21天显著高于对照组。研究表明,壳聚糖-HCG缓释制剂一次埋植后可在21d内稳定持久地释放激素,对调节鱼类的生殖机能具有良好的促进效果。       

高压蒸汽灭菌对钛合金内植入物的疲劳的影响

分析了制约骨折手术成功的因素,一是钛合金内植人物经受长期反复高压蒸汽灭菌造成材料疲劳引起断裂;二是AO手术的引起应力集中和疲劳断裂。提出了发展骨内固定植入物的建议。     

蛋白药物涂层支架的制备表征与体外释放研究

目的:探讨将蛋白大分子药物以较高的担载量涂层于心脏支架,并在不发生蛋白聚集的前提下实现数周之久缓释的方法.方法:将牛血清白蛋白通过稳定的水相-水相乳液技术制备成多糖玻璃体颗粒,并将多糖玻璃体颗粒分散于聚乳酸溶液中喷涂于支架表面制成蛋白涂层支架,在37°CPBs中进行体外释放动力学研究,用SEC-HPLC比较了蛋白涂层支架制备前后蛋白的聚集情况,并用扫描电镜等对蛋白涂层支架表面进行了表征.结果:蛋白涂层支架在电镜观察下外观圆整,表面光滑,制剂过程中未产生蛋白聚集,且能从涂层中缓慢释放达50天以上.结论:稳定的水相-水相乳液技术及其基础上制备的蛋白多糖玻璃体颗粒应用于心脏支架涂层上,能在有效保护蛋白构象的同时实现蛋白的缓释,为具有抗再狭窄活性蛋白应用于心脏支架提供了技术平台.     

PLA／PLGA及其嵌段共聚物就地成形植入装置的研究进展

介绍了就地成形载药装置概念、形成机制和应用前景并以PLA／PLGA及PLA／PLGA与PEG的三嵌段共聚物为基质的就地成形植入物,在其形成机理、制备条件、降解特性方面的研究进展进行了综述。结论是由这两类聚合物制备的就地成形植入物在药物缓释方面有着许多优良特性,但同时也有各自不足之处,它们是处于进一步研究发展阶段的新型药物缓释装置。     

猪蛔虫感染对小鼠肺部免疫病理反应的动态观察

目的：动态观察感染猪蛔虫后,小鼠肺组织的病理变化及肺泡灌洗液中相关细胞因子的变化,从而了解蛔虫感染对肺脏的侵害过程。方法：温箱孵育猪蛔虫受精卵至含蚴卵,用灌胃法感染小鼠,分别在感染后第0、7、14、45天处死小鼠,观察肺组织的病理改变,并通过ELISA方法检测肺泡灌洗液（bronchoalveolarlavagefluid,BALF）中IL-4、IFN-γ、IL-10和TGF-β1含量的动态变化。结果：感染14天组,肺组织的病理改变最为严重：大量炎症细胞浸润,嗜酸性粒细胞增多,严重者支气管狭窄,肺泡塌陷;感染45天组,小鼠肺组织病理变化比前者显著减轻。BALF中IL-4含量在感染7天、14天后分别为（169．20±34．61pg／m1）,（381．33±57．39pg／m1）,均明显高于未感染组（38．03±6．09pg／m1）;在感染45天后降低（98．49±25．33pg／m1）,但仍高于未感染组。IL-10水平在感染后降低;但感染45天组,IL-10水平却有所增高（179．78±21．33pg／m1）,并高于感染前。IFN-γ、TGF-β1,含量在感染后也有明显降低。结论：猪蛔虫感染初期,小鼠肺部损伤严重,小鼠BALF中促炎症细胞因子占主导地位;但在感染后期,BALF中促炎症细胞因子含量降低,炎症抑制因子IL-10有所增高,炎症缓和。     

猪蛔虫感染对小鼠肺部免疫病理反应的动态观察

目的:动态观察感染猪蛔虫后,小鼠肺组织的病理变化及肺泡灌洗液中相关细胞因子的变化,从而了解蛔虫感染对肺脏的侵害过程。方法:温箱孵育猪蛔虫受精卵至含蚴卵,用灌胃法感染小鼠,分别在感染后第0、7、14、45天处死小鼠,观察肺组织的病理改变,并通过ELISA方法检测肺泡灌洗液（bronchoalveolar lavage fluid,BALF）中IL-4、IFN-γ、IL-10和TGF-β₁含量的动态变化。结果:感染14天组,肺组织的病理改变最为严重:大量炎症细胞浸润,嗜酸性粒细胞增多,严重者支气管狭窄,肺泡塌陷;感染45天组,小鼠肺组织病理变化比前者显著减轻。BALF中IL-4含量在感染7天、14天后分别为（169.20±34.61pg/ml）,（381.33±57.39pg/ml）,均明显高于未感染组（38.03±6.09 pg/ml）;在感染45天后降低（98.49±25.33 pg/ml）,但仍高于未感染组。IL-10水平在感染后降低;但感染45天组,IL-10水平却有所增高（179.78±21.33 pg/ml）,并高于感染前。IFN-γ、TGF-β₁含量在感染后也有明显降低。结论:猪蛔虫感染初期,小鼠肺部损伤严重,小鼠BALF中促炎症细胞因子占主导地位;但在感染后期,BALF中促炎症细胞因子含量降低,炎症抑制因子IL-10有所增高,炎症缓和。     

碳/碳材料含硅羟基磷灰石涂层体外成骨细胞相容性研究

目的:成骨细胞在碳/碳复合材料表面羟基磷灰石涂层上有良好的长入,该实验在羟基磷灰石(hydroxyapatite HA)涂层中掺入硅后,研究成骨细胞对该涂层的生物活性,为临床骨科应用提供实验基础。方法:本研究采用化学液相气化沉积/水热法在碳/碳材料表面制备了含硅羟基磷灰石(silicon-hydroxyapatite Si-HA)涂层。在体外成骨细胞相容性的研究中,以HA涂层为对照,通过甲基噻唑基四唑(methylthiazolyl tetrazolium MTT)法测定细胞增殖反应和对细胞毒性反应,碱性磷酸酶(alkaline phosphatase ALP)测定细胞的分化,扫描电镜观察细胞生长形态,免疫荧光显影技术测定细胞的长入。结果:在HA涂层中引入硅后,Si-HA涂层和HA涂层在第2天、第4天的成骨细胞增殖实验表明前者的细胞长入数较后者多,两者的差异有统计学意义,而Si-HA涂层浸泡液中的ALP活性下降较HA涂层而言更明显,两者的差异有统计学意义,电镜扫描及荧光染色均提示在Si-HA涂层中成骨细胞的增值数更多。结论:在HA涂层中引入硅后,改变了涂层自身的晶体结构及表面电荷,同时诱导成骨细胞分泌胶原,使得成骨细胞更好的贴壁生长和增殖,成骨能力增加。在临床骨科植入物表面涂层改性上有很好的应用前景。     

呼吸机相关性肺炎鲍氏不动杆菌感染的临床特征分析

目的：研究呼吸机相关性肺炎鲍氏不动杆菌感染的临床特征。方法：选取2010 年1 月到2015 年1 月我院收治的应用呼吸 机患者130 例,根据是否合并肺炎鲍氏不动杆菌感染将患者分为研究组（86 例）和对照组（44 例）,分析呼吸机相关性肺炎鲍氏不 动杆菌的临床特征,然后根据药敏实验选择应用药物进行治疗,并观察治疗效果。结果：呼吸机相关性肺炎鲍氏不动杆菌感染的 分布科室主要以ICU 为主,大约为76.74％,神经外科次之,大约为8.14％;研究组呼吸机应用时间（18.72± 3.15）天显著长于对照 组（6.18± 0.02）天,两组比较差异具有统计学意义（P＜0.05）;研究组经舒巴坦联合左氧氟沙星或者亚胺培南治疗后总有效率为 91.86％。结论：呼吸机相关性肺炎鲍氏不动杆菌多发生于ICU,且感染者呼吸机应用时间较长,联合治疗效果显著。     

潘生丁治疗呼吸道合胞病毒肺炎机制的探讨

ＢＡＬＢ／Ｃ小鼠５５只,经鼻滴入呼吸道合胞病毒悬液１００μｌ（１０６ＰＦＵ）引起小鼠肺炎。用潘生丁（５０ｍｇ／ｋｇ·ｄ）于不同时间（感染前１天、感染同时及感染后１天）和不同剂量（１００、２５、１２．５ｍｇ／ｋｇ·ｄ）灌胃,共３天。通过病理学和组织化学方法观察鼠肺和脾脏,发生感染后１天（５０ｍｇ／ｋｇ·ｄ）给药组肺泡炎最轻,上皮细胞内病毒颗粒少,浆细胞数量多,脾动脉周围淋巴鞘Ｔ淋巴细胞增殖最轻。提示适量口服潘生丁通过抑制炎症早期Ｔ淋巴细胞增殖,促进分泌特异性抗体的浆细胞生成,减轻免疫损伤使病情改善。     

Titanium Surface Priming with Phase-Transited Lysozyme to Establish a Silver Nanoparticle-Loaded Chitosan/Hyaluronic Acid Antibacterial Multilayer via Layer-by-Layer Self-Assembly

Objectives

The formation of biofilm around implants, which is induced by immediate bacterial colonization after installation, is the primary cause of post-operation infection. Initial surface modification is usually required to incorporate antibacterial agents on titanium (Ti) surfaces to inhibit biofilm formation. However, simple and effective priming methods are still lacking for the development of an initial functional layer as a base for subsequent coatings on titanium surfaces. The purpose of our work was to establish a novel initial layer on Ti surfaces using phase-transited lysozyme (PTL), on which multilayer coatings can incorporate silver nanoparticles (AgNP) using chitosan (CS) and hyaluronic acid (HA) via a layer-by-layer (LbL) self-assembly technique.

Methods

In this study, the surfaces of Ti substrates were primed by dipping into a mixture of lysozyme and tris(2-carboxyethyl)phosphine (TCEP) to obtain PTL-functionalized Ti substrates. The subsequent alternating coatings of HA and chitosan loaded with AgNP onto the precursor layer of PTL were carried out via LbL self-assembly to construct multilayer coatings on Ti substrates.

Results

The results of SEM and XPS indicated that the necklace-like PTL and self-assembled multilayer were successfully immobilized on the Ti substrates. The multilayer coatings loaded with AgNP can kill planktonic and adherent bacteria to 100% during the first 4 days. The antibacterial efficacy of the samples against planktonic and adherent bacteria achieved 65%-90% after 14 days. The sustained release of Ag over 14 days can prevent bacterial invasion until mucosa healing. Although the AgNP-containing structure showed some cytotoxicity, the toxicity can be reduced by controlling the Ag release rate and concentration.

Conclusions

The PTL priming method provides a promising strategy for fabricating long-term antibacterial multilayer coatings on titanium surfaces via the LbL self-assembly technique, which is effective in preventing implant-associated infections in the early stage.     

Calcium Binding-Mediated Sustained Release of Minocycline from Hydrophilic Multilayer Coatings Targeting Infection and Inflammation

Infection and inflammation are common complications that seriously affect the functionality and longevity of implanted medical implants. Systemic administration of antibiotics and anti-inflammatory drugs often cannot achieve sufficient local concentration to be effective, and elicits serious side effects. Local delivery of therapeutics from drug-eluting coatings presents a promising solution. However, hydrophobic and thick coatings are commonly used to ensure sufficient drug loading and sustained release, which may limit tissue integration and tissue device communications. A calcium-mediated drug delivery mechanism was developed and characterized in this study. This novel mechanism allows controlled, sustained release of minocycline, an effective antibiotic and anti-inflammatory drug, from nanoscale thin hydrophilic polyelectrolyte multilayers for over 35 days at physiologically relevant concentrations. pH-responsive minocycline release was observed as the chelation between minocycline and Ca²⁺ is less stable at acidic pH, enabling ‘smart’ drug delivery in response to infection and/or inflammation-induced tissue acidosis. The release kinetics of minocycline can be controlled by varying initial loading, Ca²⁺ concentration, and Ca²⁺ incorporation into different layers, enabling facile development of implant coatings with versatile release kinetics. This drug delivery platform can potentially be used for releasing any drug that has high Ca²⁺ binding affinity, enabling its use in a variety of biomedical applications.     

In vitro and in vivo tests of hydrothermally synthesised hydroxyapatite coating

High pure and crystalline Hydroxyapatite (HA) coatings on titanium alloy were prepared by hydrothermal synthesis (HS) of plasma-sprayed (PS) precursors from brushite powders (HS-HA). In vitro and in vivo tests were done to evaluate its biological property. The HS-HA coating was compared with the current PS-HA coating. Cultures of the primary osteoblasts on these two HA coatings showed similar cell attachment, proliferation and alkaline phosphatase (ALP) expression. The cell morphology on the coatings was demonstrated by scanning electron microscopy (SEM). The cell spread well at 1 day after seeding culture and the extracellular matrix was secreted after 14 days culture. Histomorphometric analysis was conducted on samples implanted in femoral bone of four dogs for 1 and 3 months, and bone-implant contact percentage was evaluated by light microscopy. The calcium and phosphate distribution on the interface of bone-implant was analysed by SEM and electron dispersive X-ray (EDX) analysis. The results show the osteoconduction of HS-HA coated implants.     

Spray-dried poly(D,L-lactide) microspheres containing carboplatin for veterinary use: In vitro and in vivo studies

The aim of this study was the development of a veterinary dosage form constituted by injectable biodegradable microspheres designed for the subcutaneous release of carboplatin, a chemotherapeutic drug. Poly(D,L-lactide) (PDLLA) microspheres were prepared by an emulsification/spray-drying method, using the drug-to-polymer weight ratios 1∶9 and 1∶5; blank microspheres (1% w/v) were prepared as a comparison. Microparticles were characterized in terms of morphology, encapsulation efficiency, and in vitro drug release behavior. In vivo tests were conducted on rats by subcutaneous injection of microsphere aqueous suspensions. Levels of carboplatin were evaluated both in the skin and in serum. The microparticles obtained had a spherical shape; particle size ranged from 5 to 7 μm, dependent on drug loading. Microspheres were able to control the in vitro release of the drug: approximately 90% to 100% of the carboplatin was released over 30 days. In vivo results showed that the microspheres were able to release high drug amounts locally, and sustained serum levels of drug were also achieved. Based on these results, carboplatin-loaded PDLLA microspheres may be useful for local delivery of the antineoplastic drug to the tumor, avoiding tumor recurrence in small animals, and may decrease the formation of distant metastases. Published: September 20, 2005     

一种白细胞介素-2缓释微球制备新方法及体外表征

目的：开发一种白细胞介素-2（m-2）长效缓释微球剂型。方法：采用S／O／W法制备了白介素-2因子多糖微粒的PLGA微球,考察了微球的表面形态、粒径分布等,并且运用ELISA方法考察了微球的体外释放效果。结果：本方法制备的白介素-2因子微球光滑圆整,粒径分布较均匀,体外缓释达32天,累积释放率近90％。结论：本方法制备的白介素-2因子微球,不仅具有有效地保护IL-2蛋白活性,同时实现长效缓释的目标,是一种可行的蛋白缓释方案。     

Self-protecting bactericidal titanium alloy surface formed by covalent bonding of daptomycin bisphosphonates

Infections are a devastating complication of titanium alloy orthopedic implants. Current therapy includes antibiotic-impregnated bone cement and antibiotic-containing coatings. We hypothesized that daptomycin, a Gram-positive peptide antibiotic, could prevent bacterial colonization on titanium alloy surfaces if covalently bonded via a flexible, hydrophilic spacer. We designed and synthesized a series of daptomycin conjugates for bonding to the surface of 1.0 cm2 Ti6Al4V foils through bisphosphonate groups, reaching a maximum yield of 180 pmol/cm2. Daptomycin-bonded foils killed 53 ± 5% of a high challenge dose of 3 × 10? cfu Staphylococcus aureus ATCC 29213.     

Bi-Functionalization of a Calcium Phosphate-Coated Titanium Surface with Slow-Release Simvastatin and Metronidazole to Provide Antibacterial Activities and Pro-Osteodifferentiation Capabilities

Coating the surface of titanium implants or other bone graft substitute materials with calcium phosphate (Ca-P) crystals is an effective way to enhance the osteoconduction of the implants. Ca-P coating alone cannot confer pro-osteodifferentiation and antibacterial capabilities on implants; however, it can serve as a carrier for biological agents which could improve the performance of implants and bone substitutes. Here, we constructed a novel, bi-functional Ca-P coating with combined pro-osteodifferentiation and antibacterial capabilities. Different concentrations of metronidazole (MNZ) and simvastatin (SIM) were integrated into biomimetic Ca-P coatings on the surface of titanium disks. The biological effects of this bi-functional biomimetic coating on human bone marrow mesenchymal stem cells (hBMMSCs), human adipose derived stromal cells (hASCs), and Porphyromonas gingivalis were assessed in vitro. We observed that Ca-P coatings loaded with both SIM and MNZ display favorable release kinetics without affecting cell proliferation or attachment. In the inhibition zone test, we found that the bi-functional coating showed lasting antibacterial effects when incubated with Porphyromonas gingivalis for 2 and 4 days. Moreover, the osteodifferentiation of hBMMSCs and hASCs were increased when cultured on this bi-functional coating for 7 and 14 days. Both drugs were loaded onto the Ca-P coating at specific concentrations (10⁻⁵ M SIM; 10⁻² M MNZ) to achieve optimal release kinetics. Considering the safety, stability and low cost of SIM and MNZ, this novel bi-functional Ca-P coating technique represents a promising method to improve the performance of metal implants or other bone substitute materials, and can theoretically be easily translated to clinical applications.     

内毒素和降钙素原在妇科术后尿路感染中的鉴别诊断价值

目的评价中段尿内毒素和血清降钙素原在妇科术后不同种类细菌尿路感染中的鉴别诊断价值。方法收集临床1205例妇科术后患者中段尿进行细菌培养及内毒素检测,同时对患者进行血清降钙素原检测,比较结果对尿路感染的鉴别诊断价值。结果1205份标本中尿培养出阳性350例,感染率为29．04％,其中298例为均存在留置导尿管,而在剩余400例尿培养阴性的患者中仅仅120例留置导尿管。两组之间差异有统计学意义（χ2=26．78,P〈0．05）。其中革兰阴性杆菌189例（54％）,革兰阳性菌112例（32％）,真菌49例（14％）。在三组患者中,中段尿内毒素在革兰阴性菌引起的术后尿路感染较革兰阳性菌和真菌的患者中明显升高,差异均有统计学意义（P〈0．05）。而对于血清降钙素原在革兰阴性菌和革兰阳性菌感染的患者明显高于真菌尿路感染的患者,差异均有统计学意义（P〈0．05）。而在革兰阴性菌和革兰阳性菌感染的患者中差异无统计学意义（P〉0．05）。结论妇科术后尿路感染与留置导尿管密切相关,革兰阴性菌是引起妇科术后尿路感染的主要致病菌,中段尿内毒素有助于鉴别诊断出革兰阴性菌引起尿路感染,而血清PCT升高时则有助于排除真菌尿路感染。     

Release of Enterococcus mundtii Bacteriocin ST4SA from Self-Setting Brushite Bone Cement

Maxillofacial and craniofacial surgery is on the increase, which exposes more patients at risk of acquiring microbial infections. The use of antibiotic-loaded calcium phosphate bone cements has been shown to reduce the incidence of infection. A marked increase in antibiotic-resistant pathogens, including multidrug-resistant pathogens, has been reported. This has led to the investigation of various compounds as alternatives to conventional treatments. In this paper, we report on the incorporation and release of a broad-spectrum class II antimicrobial peptide, bacteriocin ST4SA produced by Enterococcus mundtii, into a calcium orthophosphate-based bone cement. Our results suggest class II bacteriocins may be incorporated into self-setting bone cements to produce implants with antimicrobial activity over extended periods of time.     

矾冰纳米乳对临床常见病原菌体外抗菌活性的研究

研究纳米化提高白矾与冰片复合物体外抗菌活性的效果。分别采用琼脂扩散法、体外杀菌试验及试管稀释法,测定白矾与冰片O/W型复合纳米乳对临床常见病原菌的体外抑菌、杀菌效果及最低抑菌浓度(MIC),实验中以等浓度矾冰液作为对照。结果显示,矾冰纳米乳对金黄色葡萄球菌、表皮葡萄球菌、大肠埃希菌、铜绿假单胞菌、白假丝酵母菌的抑制及杀灭活性均明显强于矾冰液(P0.05)。矾冰纳米乳对金黄色葡萄球菌、铜绿假单胞菌、大肠埃希菌临床菌株MIC90值分别为1.02、2.04和2.04 mg/mL,均明显低于矾冰液的MIC90值(P0.05)。上述实验结果提示,矾冰纳米乳与矾冰液均有广谱体外抑菌及杀菌活性,白矾及冰片复合物纳米化可提高抗菌效果。