Planton GmbH, Am Kiel-Kanal 44, D-24106 Kiel, Germany.
J Bone Joint Surg Am. 2011 May 4;93(9):840-6. doi: 10.2106/JBJS.I.01738.
A promising strategy to prevent infections around orthopaedic titanium implants is to use naturally occurring cationic antimicrobial peptides (CAMPs) such as the human β-defensin-2 as antibacterial coatings. Human antimicrobial peptides represent a part of the innate immune system and have a broad antimicrobial spectrum against bacteria, fungi, and viruses.
In the present study, titanium surfaces were functionalized by four different self-assembled monolayers (SAMs) forming methoxy silanes: (1) hexadecyltrimethoxysilane, (2) dimethoxymethyloctylsilane, (3) allyltrimethylsilane, and (4) 3-aminopropyltrimethoxysilane. In addition, calf skin type-I collagen was cross-linked to the SAM surface 3-aminopropyltrimethoxysilane by means of two different treatments: (1) N-hydroxysuccinimide and (2) glutaraldehyde. The functionalized titanium surfaces were coated with recombinant human β-defensin-2 (rHuβD2), an antimicrobial peptide, and were tested for antibacterial activity against Escherichia coli. The release of rHuβD2 was quantified by means of enzyme-linked immunosorbent assay (ELISA).
The coating of functionalized titanium surfaces with rHuβD2 was successful. Recombinant HuβD2 was eluted from the titanium surfaces continuously, yielding antimicrobial activity up to several hours. Antimicrobial activity with a killing rate of 100% was observed for all functionalized titanium surfaces after two hours of incubation. The dimethoxymethyloctylsilane-functionalized titanium surface delivered 0.65 μg of rHuβD2 after six hours with a 60% bacterial killing rate. The silane-functionalized surfaces exhibited a faster release of antimicrobially active rHuβD2 compared with collagen modifications.
Natural antibiotics such as rHuβD2 integrated into the metal surface of titanium implants may be a promising tool to prevent and control infections around orthopaedic implants.
预防骨科钛植入物周围感染的一种有前景的策略是使用天然存在的阳离子抗菌肽（CAMPs），如人β-防御素-2 作为抗菌涂层。人抗菌肽是先天免疫系统的一部分，对细菌、真菌和病毒具有广谱的抗菌作用。
在本研究中，通过形成甲氧基硅烷的四种不同自组装单层（SAMs）对钛表面进行功能化：（1）十六烷基三甲氧基硅烷，（2）二甲氧基甲基辛基硅烷，（3）烯丙基三甲氧基硅烷，和（4）3-氨丙基三甲氧基硅烷。此外，牛皮 I 型胶原蛋白通过两种不同的处理交联到 SAM 表面 3-氨丙基三甲氧基硅烷：（1）N-羟基琥珀酰亚胺和（2）戊二醛。功能化的钛表面涂有重组人β-防御素-2（rHuβD2），一种抗菌肽，并测试了其对大肠杆菌的抗菌活性。通过酶联免疫吸附试验（ELISA）定量释放 rHuβD2。
成功地在功能化的钛表面上涂覆 rHuβD2。重组 HuβD2 从钛表面连续洗脱，产生长达数小时的抗菌活性。孵育两小时后，所有功能化的钛表面均观察到抗菌活性达到 100%的杀菌率。二甲基甲氧基辛基硅烷功能化的钛表面在六小时后释放 0.65μg 的 rHuβD2，具有 60%的杀菌率。与胶原蛋白修饰相比，硅烷功能化表面表现出更快释放具有抗菌活性的 rHuβD2。
整合到钛植入物金属表面的天然抗生素，如 rHuβD2，可能是预防和控制骨科植入物周围感染的一种有前途的工具。
