Liposomes are widely used as synthetic analogues of cell membranes and for drug delivery. Lipid-binding DNA nanostructures can modify the shape, porosity and reactivity of liposomes, mediated by cholesterol modifications. DNA nanostructures can also be designed to switch conformations by DNA strand displacement. However, the optimal conditions to facilitate stable, high-yield DNA–lipid binding while allowing controlled switching by strand displacement are not known. Here, we characterized the effect of cholesterol arrangement, DNA structure, buffer and lipid composition on DNA–lipid binding and strand displacement. We observed that binding was inhibited below pH 4, and above 200 mM NaCl or 40 mM MgCl2, was independent of lipid type, and increased with membrane cholesterol content. For simple motifs, binding yield was slightly higher for double-stranded DNA than single-stranded DNA. For larger DNA origami tiles, four to eight cholesterol modifications were optimal, while edge positions and longer spacers increased yield of lipid binding. Strand displacement achieved controlled removal of DNA tiles from membranes, but was inhibited by overhang domains, which are used to prevent cholesterol aggregation. These findings provide design guidelines for integrating strand displacement switching with lipid-binding DNA nanostructures. This paves the way for achieving dynamic control of membrane morphology, enabling broader applications in nanomedicine and biophysics.

Sixteen hundred and eighty breast aspiration specimens obtained from 1410 patients seen in office practice were reviewed. The cytologic diagnosis was unsatisfactory in 230 cases, benign in 1019 cases, atypical in 198 cases, suspicious for malignancy in 102 cases, and malignant in 131 cases. All cases diagnosed as cytologically malignant had a subsequent tissue diagnosis of malignant neoplasm. Four percent of the cytologically benign cases and 17% of the cytologically atypical cases had malignant neoplasms. Clinical and cytologic examination detected more cancers (87%) than did clinical and mammographic examination (79%). Ninety‐three percent of malignant neoplasms were detected by the combination of clinical, cytologic, and mammographic examination. Aspiration cytology significantly contributes to the clinical evaluation of mammary lesions in office practice, but it does not replace tissue biopsy or careful follow‐up of mammary lesions of clinical concern. Proof of the presence of breast cancer by aspiration in the office may obviate the need for a two‐stage procedure in the surgical management of breast cancer. Aspiration of minimally suspicious lesions often is helpful in initiating excisional biopsy in some occult, clinically unrecognized breast cancers.

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