Harris L G, Mead L, Müller-Oberländer E, Richards R G
AO Research Institute, Clavadelerstrasse, 7270 Davos, Switzerland.
J Biomed Mater Res A. 2006 Jul;78(1):50-8. doi: 10.1002/jbm.a.30611.
Acute and chronic osteomyelitis caused by staphylococci can be difficult to treat by conventional means and often has marked consequences for the patient. Current methods of treatment involve the use of systemic antibiotics, the local implantation of nondegradable drug carriers, and surgical debridement. A possible solution that could prevent initial bacterial adhesion could be to modify the implant surface with an antimicrobial coating while maintaining biocompatibility to host cells. This study describes the cytocompatibility evaluation of different coatings (poly(D,L-lactide) (PDLLA), politerefate (PTF), calcium phosphate/anodic plasma-chemical treatment (CaP/APC), polyurethane (PU), and polyvinylpyrollidone (PVP) on titanium surfaces with and without chlorhexidine diacetate (CHA) to Staphylococcus aureus, Staphylococcus epidermidis, and hTERT human fibroblasts. Surface characterization of the coatings showed no significant variation in the roughness or hydrophobicity of the coated surfaces, except the CaP/APC surface that was porous yet the smoothest, and PVP, PVP+CHA, and CaP/APC+CHA that were more hydrophilic in nature than the others. On the surfaces without CHA, both staphylococcal strains and spread fibroblasts were observed, but on the CHA impregnated surfaces few bacteria and no intact fibroblasts were seen. Flow cytometry found fewer bacteria in the media and on the surfaces containing CHA in comparison to the surfaces without CHA. The release kinetics varied from slow (over 200 h) to burst release: PDLLA>PTF>PU>CaP/APC=PVP. This study showed that PDLLA and PTF have the best potential as coatings on implants for drug delivery, as they were cytocompatible to hTERT fibroblasts, eluted CHA effectively, and passed mechanical testing. The actual release kinetics of PDLLA and PTF are important, as the amount of CHA present should remain above the minimal inhibitory concentration value for a limited time before disappearing completely.
由葡萄球菌引起的急慢性骨髓炎采用传统方法治疗可能较为困难，且往往给患者带来显著后果。当前的治疗方法包括使用全身性抗生素、局部植入不可降解药物载体以及手术清创。一种可能预防初始细菌黏附的解决方案是用抗菌涂层修饰植入物表面，同时保持与宿主细胞的生物相容性。本研究描述了不同涂层（聚（D，L - 丙交酯）（PDLLA）、聚对苯二甲酸乙二酯（PTF）、磷酸钙/阳极等离子体化学处理（CaP/APC）、聚氨酯（PU）和聚乙烯吡咯烷酮（PVP））在有和没有双醋酸氯己定（CHA）的情况下，对金黄色葡萄球菌、表皮葡萄球菌和hTERT人成纤维细胞在钛表面的细胞相容性评估。涂层的表面表征显示，除了多孔但最光滑的CaP/APC表面以及本质上比其他表面更亲水的PVP、PVP + CHA和CaP/APC + CHA表面外，涂层表面的粗糙度或疏水性没有显著变化。在没有CHA的表面上，观察到了两种葡萄球菌菌株和成纤维细胞的扩散，但在CHA浸渍的表面上几乎看不到细菌且没有完整的成纤维细胞。流式细胞术发现，与没有CHA的表面相比，含有CHA的培养基和表面上的细菌较少。释放动力学从缓慢（超过200小时）到突发释放不等：PDLLA>PTF>PU>CaP/APC = PVP。本研究表明，PDLLA和PTF作为植入物药物递送涂层具有最佳潜力，因为它们对hTERT成纤维细胞具有细胞相容性，能有效洗脱CHA，并通过了机械测试。PDLLA和PTF的实际释放动力学很重要，因为CHA的存在量在完全消失之前应在有限时间内保持高于最低抑菌浓度值。
