By designing and attaching a synthetic cyclic-RGD, selectivity between primary cancer cells (BT-549) and metastatic cancer cells (MDA-MB 435) is achieved with enhanced particle uptake by the metastatic cancer cell line. Incorporation of the hydrophobic drug Camptothecin into these two types of biomolecular-targeted nanoparticles causes an increase in mortality of the targeted cancer cells compared to that caused by both the free drug and nontargeted particles.

This paper introduces the unnatural amino acids m-Abc2K and o-Abc2K as nanometer-sized building blocks for the creation of water-soluble macrocycles with well-defined shapes. m-Abc2K and o-Abc2K are homologues of the nanometer-sized amino acid Abc2K, which we recently introduced for the synthesis of water-soluble molecular rods of precise length. [J. Am. Chem. Soc. 2007, 129, 7272]. Abc2K is linear (180°), m-Abc2K creates a 120° angle, and o-Abc2K creates a 60° angle. m-Abc2K and o-Abc2K are derivatives of 3’-amino-[1,1’-biphenyl]-4-carboxylic acid and 2’-amino-[1,1’-biphenyl]-4-carboxylic acid, with two propyloxyammonium side chains for water solubility.

This paper introduces the unnatural amino acid Abc2K as a nanometer-length building block for the creation of water-soluble molecular rods of exceptional size. Abc2K is a water-soluble variant of the unnatural amino acid 4’-amino-[1,1’-biphenyl]-4-carboxylic acid (Abc) with lysinelike propyloxyammonium side chains at the 2- and 5-positions. The protected building block Fmoc-Abc2K(Boc)-OH (1) can be used in standard Fmoc-based solid-phase peptide synthesis to create water-soluble rodlike peptides in nanometer unit lengths up to at least ten nanometers.