Effectiveness of cleaning surgical implants: quantitative analysis of contaminant removal

Surgical implants need to be free from contaminants before implantation. The effectiveness of a presently used Clemson bioengineering cleaning (CBC) protocol was evaluated for cleaning three different biomaterials (titanium, aluminum oxide, and polyethylene terephthalate, PET) contaminated with three different contaminants (calcium chloride, zinc chloride, and hexadecane). Radiolabeled tracer analysis (RTA), with the use of liquid scintillation, was used as the surface analytical technique to quantitatively determine the percent contaminant removed from the biomaterial surface. On average, the ultrasonic cleaning step removed 99.96% of all three contaminants from both titanium and aluminum oxide. The CBC protocol did not sufficiently clean PET fabric contaminated with hexadecane leaving 11.76% of the contaminant after the ultrasonic step. With the use of isopropyl alcohol in series with 1% Liquinox, the ultrasonic step cleaned the fabric soiled with hexadecane within 30 min, removing 99.85% of the hexadecane initially on the surface. RTA proved to be an excellent method of quantifying surface contamination on implant materials, and for assessing the effectiveness of cleaning protocols in question.