کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10159221 39 2014 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
In vitro and in vivo evaluation of ultrananocrystalline diamond as an encapsulation layer for implantable microchips
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
In vitro and in vivo evaluation of ultrananocrystalline diamond as an encapsulation layer for implantable microchips
چکیده انگلیسی
Thin ultrananocrystalline diamond (UNCD) films were evaluated for use as hermetic and bioinert encapsulating coatings for implantable microchips, where the reaction to UNCD in vitro and in vivo tissue was investigated. Leakage current tests showed that depositing UNCD coatings, which were conformally grown in (1% H2) Ar/CH4 plasma, on microchips rendered the surface electrochemically inactive, i.e. with a very low leakage current density (2.8 × 10−5 A cm−2 at −1 V and 1.9 × 10−3 A cm−2 at ± 5 V) ex vivo. The impact of UNCD with different surface modifications on the growth and activation of macrophages was compared to that of standard-grade polystyrene. Macrophages attached to oxygen-terminated UNCD films down-regulated their production of cytokines and chemokines. Moreover, with UNCD-coated microchips, which were implanted subcutaneously into BALB/c mice for up to 3 months, the tissue reaction and capsule formation was significantly decreased compared to the medical-grade titanium alloy Ti-6Al-4V and bare silicon. Additionally, the leakage current density, elicited by electrochemical activity, on silicon chips encapsulated in oxygen-terminated UNCD coatings remained at the low level of 2.5 × 10−3 A cm−2 at 5 V for up to 3 months in vivo, which is half the level of those encapsulated in hydrogen-terminated UNCD coatings. Thus, controlling the surface properties of UNCDs makes it possible to manipulate the in vivo functionality and stability of implantable devices so as to reduce the host inflammatory response following implantation. These observations suggest that oxygen-terminated UNCDs are promising candidates for use as encapsulating coatings for implantable microelectronic devices.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Biomaterialia - Volume 10, Issue 5, May 2014, Pages 2187-2199
نویسندگان
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