MEDICAL SCIENCES Correction for “Prolonged duration local anesthesia with minimal toxicity,” by Hila Epstein-Barash, Iris Shichor, Albert H. Kwon, Sherwood Hall, Michael W. Lawlor, Robert Langer, and Daniel S. Kohane, which appeared in issue 17, April 28, 2009, of Proc Natl Acad Sci USA (106:7125–7130; first published April 13, 2009; 10.1073/pnas.0900598106).
The authors note that on page 7129, left column, fourth full paragraph, sentences 3 through 5, “DSPC:DSPG:cholesterol or DMPC:DMPG-cholesterol (molar ratio 3:1:2) were dissolved in t-butanol. Dexamethasone was added in some samples before lyophilization. The lyophilized cake was hydrated with 250 mM ammonium sulfate or, in some groups, with 0.1 mg STX, at 55–60 °C.” should instead appear as “DSPC:DSPG:cholesterol or DMPC:DMPG-cholesterol (molar ratio 3:1:2) were dissolved in 9:1 vol/vol chloroform:methanol solution. Dexamethasone was added in some samples. A thin lipid film was obtained by drying the lipid mixture in a rotary evaporator at 60 °C. The pressure in the evaporator was maintained at 480 torr for 20 minutes and then gradually decreased to 20 torr over a period of 30 min. The lipid film was reconstituted in t-butanol at 55–60 °C and immediately cooled by immersing in liquid nitrogen. The sample was then transferred to a lyophilizer for 24 h. The lyophilized cake was hydrated with 250 mM ammonium sulfate or, in some groups, with 1.0 mg STX, at 55–60 °C.”