Klueh U, Wagner V, Kelly S, Johnson A, Bryers J D
The Center for Biomaterials, The University of Connecticut Health Center, Farmington, CT 06030-1615, USA.
J Biomed Mater Res. 2000;53(6):621-31. doi: 10.1002/1097-4636(2000)53:6<621::aid-jbm2>3.0.co;2-q.
Efficacy of silver-coated poly(ethylene terephthalate) to prevent bacterial attachment and subsequent infection was quantified in vitro, in both batch- and flowing-fluid experiments. Kinetic analysis of batch suspended cell cultures of Staphylococcus epidermidis (SE), at various growth-limiting nutrient concentrations, in the absence of any fabric, indicated a maximum culture growth rate constant micro(max) = 0.78 +/- 0.02 h(-1). Batch experiments for Control fabric samples indicated that SE cultures exhibited about the same suspended cell growth rate (0.72 +/- 0.02 h(-1)) as observed in batch suspended cultures without fabric. Suspended SE cultures in the presence of silver-coated fabric grew at a considerably lower rate, 0.15 +/- 0.01 h(-1), indicating the inhibitory effect of Ag(+2) ion released from the fabric. Growth rates of suspended SE cultures were 5-6 times higher in the fluid phase in contact with the Control fabric compared to cultures exposed to silver-coated fabric. Maximum suspended cell concentrations attained at time = 24 h were 1-2 orders of magnitude higher for Control fabrics vs. silver-coated fabric. In all batch colonization experiments, both live and dead SE bacterial cells accumulate on the surfaces of both silver-coated and Control fabrics. Adherent viable SE cells accumulated to 1-2 orders of magnitude more ( approximately 5 x 10(+8) cells/cm(2)) on Control fabric than SE cells on the silver-coated fabric ( approximately 1.1 x 10(+6) cells/cm(2)), respectively. Between 70-95% SE cells on the Control fabric were viable, while on the silver-coated fabric samples, at 24 h, viable cells were less than 10% of the adherent community (i.e., greater than 90% nonviable cells). In flow cell colonization experiments, SE cells accumulated on Control fabric to a maximum adherent cell concentration of 6 x 10(+7) - 8 x 10(+7) cells/cm(2) by 24 h with the proportion of viable cells remaining relatively constant at 76% throughout an experiment. Both noninvasive microscopic enumeration and destructive assays gave the same results for adherent cell numbers. Using silver-coated fabric, total cells numbers (live + dead) reached a level of approximately 1.1 x 10(+7) - 3.0 x 10(+7) cells/cm(2) after about 6 h and remained constant. However, while the proportion of viable cells initially on the surface was 63-75%, this fraction dropped continuously during each experiment to less than 6% viable cells at 24 h. Regardless of the criteria, the number of viable or nonviable cells attached to silver-coated fabric were significantly lower than on Control fabric.
在分批和流动流体实验中，对体外镀银聚对苯二甲酸乙二酯预防细菌附着及后续感染的功效进行了量化。在各种生长限制营养浓度下，于无任何织物的情况下，对表皮葡萄球菌（SE）的分批悬浮细胞培养物进行动力学分析，结果表明最大培养生长速率常数μ(max)=0.78±0.02 h⁻¹。对照织物样品的分批实验表明，SE培养物的悬浮细胞生长速率（0.72±0.02 h⁻¹）与无织物的分批悬浮培养中观察到的相近。在有镀银织物存在的情况下，悬浮的SE培养物生长速率显著更低，为0.15±0.01 h⁻¹，这表明从织物中释放的Ag⁺²离子具有抑制作用。与暴露于镀银织物的培养物相比，与对照织物接触的流体相中悬浮SE培养物的生长速率高5至6倍。在24小时时，对照织物达到的最大悬浮细胞浓度比镀银织物高1至2个数量级。在所有分批定殖实验中，活的和死的SE细菌细胞都在镀银织物和对照织物表面积累。对照织物上附着的存活SE细胞积累量比镀银织物上的SE细胞多1至2个数量级（分别约为5×10⁺⁸个细胞/cm²和1.1×10⁺⁶个细胞/cm²）。对照织物上70 - 95%的SE细胞是活的，而在镀银织物样品上，在24小时时，活细胞占附着群落的比例不到10%（即超过90%的细胞无活性）。在流动小室定殖实验中，到24小时时，SE细胞在对照织物上积累至最大附着细胞浓度为6×10⁺⁷ - 8×10⁺⁷个细胞/cm²，在整个实验过程中活细胞比例相对恒定在76%。非侵入性显微镜计数和破坏性测定法对附着细胞数量得出的结果相同。使用镀银织物时，大约6小时后总细胞数（活细胞 + 死细胞）达到约1.1×10⁺⁷ - 3.0×10⁺⁷个细胞/cm²并保持恒定。然而，虽然表面最初的活细胞比例为63 - 75%，但在每个实验过程中该比例持续下降，到24小时时活细胞比例降至不到6%。无论依据何种标准，附着在镀银织物上的活细胞或死细胞数量均显著低于对照织物。
