abstract |
Compounds arc provided having the following structure:or a pharmaceutically acceptable salt, tautomer or stereoisomer thereof, wherein R<sup>1a</sup>, R<sup>1b</sup>, R<sup>2a</sup>, R<sup>2b</sup>, R<sup>3a</sup>, R<sup>3b</sup>, R<sup>4a</sup>, R<sup>4b</sup>, R<sup>5</sup>, R<sup>6</sup>, R<sup>7</sup>, R<sup>8</sup>, R<sup>9</sup>, L<sup>1</sup>, L<sup>2</sup>, a, b, c, d and c are as defined herein. Use of the compounds as a component of lipid nanoparticlc formulations for delivery of a therapeutic agent, compositions comprising the compounds and methods for their use and preparation arc also provided. |