Liposomes as lubricants: beyond drug delivery

► Gel-phase HSPC liposomes spontaneously self-assemble onto solid surfaces to form a closed packed layer. ► Such HSPC coating reduced the sliding friction coefficients to strikingly-low levels down to 2 × 10−5 in pure water or 6 × 10−4 at high salt, up to contact pressures of order 107 Pa, comparable with those in the major joints. ► This suggests an important role for phosphatidylcholines in biological lubrication.