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ACS Appl Mater Interfaces. 2023 Oct 11;15(40):46626-46638. doi: 10.1021/acsami.3c08734. Epub 2023 Oct 2.
A one-step modification of biomedical silicone tubing with ,-dimethyltetradecylamine, C14, results in a composition designated WinGard-1 (WG-1, 1.1 wt % C14). A surface-active silicon-amine phase (SAP) is proposed to account for increased wettability and increased surface charge. To understand the mechanism of antimicrobial effectiveness, several procedures were employed to detect whether C14 leaching occurred. An immersion-growth (IG) test was developed that required knowing the bacterial Minimum Inhibitory Concentrations (MICs) and Minimum Biocidal Concentrations (MBCs). The C14 MIC and MBC for Gm- uropathogenic (UPEC), commonly associated with catheter-associated urinary tract infections (CAUTI), were 10 and 20 μg/mL, respectively. After prior immersion of WG-1 silicone segments in a growth medium from 1 to 28 d, the IG test for the medium showed normal growth for UPEC over 24 h, indicating that the concentration of C14 must be less than the MIC, 10 μg/mL. GC-MS and studies of the medium inside and outside a dialysis bag containing WG-1 silicone segments supported leaching. Consequently, a 5 log UPEC reduction (99.999% kill) in 24 h using the shake flask test (ASTM E2149) cannot be due to leaching and is ascribed to contact kill. Interestingly, although the MBC was greater than 100 μg/mL for , WG-1 silicone affected an 80% reduction via a 24 h shake flask test. For other bacteria and , greater than 99.9% shake flask kill may be understood by proposing increased wettability and concentration of charge illustrated in the TOC. leaching places WG-1 silicone at an advantage over conventional anti-infectives that rely on leaching of an antibiotic or heavy metals such as silver. The facile process for preparation of WG-1 silicone combined with biocidal effectiveness comprises progress toward the goals of device designation from the FDA for WG-1 and clearance.
用 ，-二甲基十四烷基胺（C14）对生物医学硅酮管进行一步修饰，得到一种名为 WinGard-1（WG-1，1.1wt% C14）的组合物。提出表面活性硅-胺相（SAP）来解释其润湿性和表面电荷增加的原因。为了了解抗菌有效性的机制，采用了几种程序来检测 C14 是否浸出。开发了一种浸泡生长（IG）试验，该试验需要了解细菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。GM-尿路致病性大肠杆菌（UPEC）的 C14 MIC 和 MBC 分别为 10 和 20μg/mL，UPEC 通常与导管相关尿路感染（CAUTI）有关。在 WG-1 硅酮段在生长培养基中浸泡 1 至 28 天后，IG 试验显示 UPEC 在 24 小时内的培养基中正常生长，这表明 C14 的浓度必须小于 MIC，即 10μg/mL。GC-MS 和对含有 WG-1 硅酮段的透析袋内外介质的研究支持浸出。因此，在摇瓶试验（ASTM E2149）中，在 24 小时内对 UPEC 的减少量为 5 对数（99.999%的杀灭）不能归因于浸出，而是归因于接触杀灭。有趣的是，尽管 C14 的 MBC 大于 100μg/mL，但 WG-1 硅酮在 24 小时摇瓶试验中仍能降低 80%。对于其他细菌和 C14，通过提出在 TOC 中说明的增加的润湿性和电荷浓度，可以理解大于 99.9%的摇瓶杀灭。浸出使 WG-1 硅酮具有优于传统抗感染药物的优势，后者依赖于抗生素或重金属（如银）的浸出。WG-1 硅酮制备的简便过程与生物杀灭效果相结合，构成了朝着 FDA 对 WG-1 进行设备指定和清除的目标取得进展。
