In this proposal we want to characterize the physico-chemical properties of self-assembling nanogels composed of octenyl-succinic anhydride modified hyaluronic acid (OSA-HA) encapsulating cell-penetrating peptides (CPPs). CPPs are short amino acid chains (10-50 AAs) which have shown to enhance transport of cargos, such as insulin into or across cells. We have assessed the formation of nanogels with a lipophilic antibiotic and an antimicrobial peptide and have noticed a difference in structural organization, but we still lack fundamental understanding on what causes the changes in the structure of the nanogels upon drug loading. We would like to use a range of 12 peptides - from more cationic to neutral and more hydrophilic to more hydrophobic - for nanogel formulation and assess the changes in nanogel structure as a result of peptide charge and hydrophobicity.