JOURNAL OF COSMETIC SCIENCE 96 effectiveness at pH levels above 7.0, TRIS buffer remained highly effective at increased pH levels. The application of TRIS buffer could extend the effi cacy of anionic particles to higher pH values. ASSESSMENT OF CMC ANTIMICROBIAL EFFICACY Neither charged particle signifi cantly affected C. albicans viability (Table IV). Removal of yeast from skin tape strips using anionic particles as described does not kill or inhibit the growth of the microbes. PRETREATMENT OF SKIN TAPE STRIPS WITH CMC Pretreatment of the skin tape strips with CMC did not prevent yeast attachment, as established by the numbers of yeast cells counted on treated and untreated tape strips (Table V). A t-test on the average numbers of yeast cells observed for the triplicate treated and untreated strips indicated no signifi cant differences (p = 0.264). Table III Percent Removal of Yeast from Skin Tape Strips as Measured by Visual Observation (n = 3) Material Concentration (mg/ml) Size AVG SD Percent Removal Benonite 8.0 Powder 198.7 6.8 38.2 CM-Cellulose 8.0 Fibrous 317.0 24.8 1.5 Cellulose 8.0 Fibrous 294.7 21.2 8.4 DEAE-Cellulose 8.0 Powder 293.3 14.3 8.8 QAE-Cellulose 8.0 Fibrous 289.0 30.5 10.2 Cellulose-Phosphate 8.0 Powder 339.3 40.1 −5.5 Chitin 8.0 Powder 279.7 20.5 13.1 Figure 2. Visual counts of C. albicans on tape strips after exposure to 3–4 μm CMC particles ■ = Skin treated with 0.25 mg/mL CMC ▲ = Untreated skin Bars = SD (n=3).

RELEASE OF C. ALBICANS FROM SKIN 97 SIMULTANEOUS ADDITION OF YEAST AND CMC TO SKIN TAPE STRIPS When added during the process of yeast attachment, CMC inhibited the attachment process (Table VI). This result indicates a possible application of charged particles as a preventative measure to inhibit yeast attachment to the skin tape strips. DISCUSSION Bacteria, fungi, and soil particles adhere to the skin despite their negative charges, which should repel the negatively charged skin (3,4,15,18). Many different binding mechanisms contribute to the binding of microbes to the skin surface, and the com- bined strength of these adhesion interactions is far greater than that of any single at- tachment mechanism (3,12,20). Surfactants and solvents are effective and commonly used methods of cell release from surfaces however, they can be harsh and potentially damaging to human skin. Even minimal use of detergents and organic solvents can Figure 3. C. albicans release from tape strips as a function of time. Samples were exposed to 3-4 μm CMC particles, and percent release was determined using the viable count method to compare treated and un- treated samples. ■ = Skin treated with 0.25 mg/mL CMC ▲ = Untreated skin Bars = SD (n=3). Figure 4. C. albicans cells (white rods) are displaced by CMC particles. Photomicrographs of skin before and after treatment with 3–4 μm CMC particles (0.25 mg/mL) for 20 min at 25°C were taken with Olympus BH2, UV excitation, and a SPOT digital camera.