Rodil S E, Olivares R, Arzate H
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito exterior s/n, CU, 04510 México DF.
Biomed Mater Eng. 2005;15(1-2):101-12.
Amorphous carbon (a-C), carbon nitride (a-CN) and titanium films were deposited on stainless steel substrates (SS) using a dc magnetron sputtering system attached to a high vacuum chamber. Films were deposited using a base pressure of 1.3x10(-4) Pa. For the carbon films a pure graphite target was eroded in an Argon plasma. For the case of the a-CN films, the Ar flux was substituted by 100% N2 gas. Titanium films were deposited in a different chamber, using a pure Ti target and an argon plasma. In vitro studies were carried out on the coated samples using human osteoblasts cells. Cytotoxicity of carbon films was assessed by cellular adhesion and proliferation, as determined by direct cellular counting using a spectroscopic technique and a well-defined standard curve. Osteoblasts cells were also grown on uncoated steel and prepared Petri dishes for comparison. The percentage of osteoblasts adhesion measured at 24 hrs attained maximum values for the a-C films. Similarly, cellular proliferation evaluated at three, five and seven days showed an outstanding increase of osteoblasts cells for the a-C and Ti coatings in contrast to the uncoated steel. The cell functionality was evaluated by the MTT test after incubation periods of 3, 5 and 7 days. The absorbance values obtained for a-C, a-CN and Ti surfaces resulted significantly higher with respect to the positive control, indicating that the surface did not induce any toxic effect. Preliminary bio-mineralization was evaluated by measuring the elemental composition of the mineral grown on the substrates after periods up to 14 days.
采用连接高真空腔室的直流磁控溅射系统，在不锈钢基底（SS）上沉积非晶碳（a-C）、氮化碳（a-CN）和钛薄膜。在1.3×10⁻⁴ Pa的本底压力下进行薄膜沉积。对于碳薄膜，在氩等离子体中腐蚀纯石墨靶。对于a-CN薄膜的情况，用100%的氮气代替氩气流量。钛薄膜在不同的腔室中沉积，使用纯钛靶和氩等离子体。使用人成骨细胞对涂覆样品进行体外研究。通过细胞粘附和增殖评估碳薄膜的细胞毒性，这是通过使用光谱技术和明确的标准曲线进行直接细胞计数来确定的。成骨细胞也在未涂覆的钢和制备好的培养皿上生长以作比较。在24小时时测量的成骨细胞粘附百分比，a-C薄膜达到最大值。同样，在三天、五天和七天时评估的细胞增殖显示，与未涂覆的钢相比，a-C和钛涂层的成骨细胞有显著增加。在3天、5天和7天的孵育期后，通过MTT试验评估细胞功能。a-C、a-CN和钛表面获得的吸光度值相对于阳性对照显著更高，表明该表面未诱导任何毒性作用。通过测量在长达14天的时间段后在基底上生长的矿物质的元素组成来评估初步生物矿化。
