ABSTRACTS 249 Enhancement of DNA repair of UV damage in mouse and human skin by liposomes con- taining a DNA repair enzyme Daniel B. Yarosh, Applied Genetics, Inc., 205 Buffalo Avenue, Freeport, N.Y. ! 1520 Sunlight and ultraviolet light (UV) in particular have many deleterious effects on skin, including the induction of skin cancer. The DNA of epidermal cells is the target for an important part of this damage. After UV exposure little or nothing can be done at present to reverse the long-term effects. A new approach has been developed to repair DNA after sun exposure. A highly purified DNA repair enzyme, which initiates removal of specific DNA lesions produced by UV, was encapsulated in lipo- somes and delivered to UV-irradiated human epi- dermal keratinocytes in culture and to the skin of UV-irradiated hairless mice by topical application. In treated cells and animals, removal of damage was faster, DNA repair was enhanced, and the survival of cells after exposure was significantly increased compared to untreated or sham-treated controls. These results suggest that delivery of DNA repair enzymes to human skin may become a practical method to prevent sunlight damage even after UV exposure. New hydrogels--Basic technology and applica- tion Steve Greenberg, Ph.D., Lipo Chemicals, Inc., 207 19th Avenue, Paterson, NJ 07504 Synthetic hydrogels have been used in soft contact lenses and other related biomedical applications as well as in cosmetic and personal care products. In this paper we introduce a new family of patented synthetic hydrogels that are multi-block co- polymers derived from poly(acrylonitrile). These new hydrogels utilize strong physical interactions in maintaining their three-dimensional integrity rather than the covalent crosslinking on which other synthetic hydrogels depend. These new hydrogels are close analogues of natural hydrogels such as those found in the cornea and cartilage. They pos- sess superior physical and mechanical properties over other synthetic hydrogels. This paper focuses on the basic technology of this new type of hydrogel such as structure, pH, vis- cosity, and concentration relationships. It also dis- cusses applications of these new hydrogels to cos- metic formulations, including their use as primary emulsifiers in water-in-oil emulsions, as stabilizers for multi-phase emulsions, and as a source of unique and desirable tactile properties in gels.