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.

JOURNAL OF COSMETIC SCIENCE 98 greatly impact the integrity of the stratum corneum barrier and potentially cause skin irritation (24). Electrostatic removal of contaminants from the skin surface, using negatively charged particles to reduce the attractive forces between the contaminant and the skin, offers a potential method to clean the skin with reduced risk of skin irritation. Negatively charged CMC particles (3–4 μm), as well as other anionic materials or cationic exchangers, in close proximity to the attached microbe appear to act electrostatically on the skin tape strips and attached C. albicans with suffi cient strength to overcome the combined binding affi n- ity between them (Figures 1 and 3). The released microbe can then be transferred to the cleaning substrate (wipe, diaper, cloth) to facilitate contaminant removal. The CMC mi- croparticles do not exhibit biocidal or biostatic properties (Table IV) and are not antici- pated to have harsh or damaging effects on the skin. C. albicans, a causative agent of diaper rash known to have multiple mechanisms (electro- static, hydrophobic, and adhesin interactions) of attachment to mammalian skin (4,12,15), was removed from skin cells bound to a tape strip by what appears to be an electrostatic interaction (Figures 1 and 3). After a 10-min exposure to the CMC particles, greater than 95% of the bound yeast was removed from the skin tape strips (Table II) based on visual Figure 5. Effects of pH on removal of yeast from tape strips using 3–4 um CMC particles (0.25 mg/ml) as determined by visual counts ▼ = Citrate-Phosphate Buffer ♦ = Phosphate Buffer ▲= HEPES Buffer ■ = TRIS Buffer Bars = SD (n=3). Table IV Viability of C. albicans When Exposed to CMC or Cellulose Phosphatea Exposure time (min) CFU/ml Control CMC Cellulose phosphate 0 1.12 × 105 1.07 × 105 1.12 × 105 15 1.29 × 105 1.27 × 105 1.35 × 105 30 1.31 × 105 1.14 × 105 1.18 × 105 60 1.27 × 105 1.29 × 105 1.66 × 105 210 8.45 × 104 9.97 × 104 1.35 × 105 a 210-min exposure n = 3.