Fig. 2. Synthesis of RGD peptide-based lipids by reaction between RGD peptide heads and alkyl tails. (A) Four RGD peptide heads and five alkyl tails were chosen for the formation of 20 unique RGD-peptide based lipids. (B) Lipids were synthesized by reacting heads and tails in ethanol for 3 days at 70 °C.