Physical hydrogels that are based on peptides that are held together by non-covalent interactions are interesting materials that received significant attention in recent years. The individual peptides self-assemble into fibers and entanglement of these fibers leads to the formation of hydrogels. Interestingly, the non-covalent nature often induces shear-thinning behavior, which allows aspiration through a needle and administration by injection.<br/>Despite the vast amount of work published on peptide hydrogels in recent years, when aiming for the controlled delivery of drugs, specific challenges still need to be addressed. These include fine-tuning of mechanical properties, control over drug release rate and mechanism, and the determination of (long-term) toxicity. Herein, we first report the synthesis and characterization of a relatively simple, but tunable, hexapeptide, solely consisting of natural amino acids, able to form a stable hydrogel under physiologically relevant conditions and that exhibits promising release properties for hydrophobic small molecule cargos. Subsequent work on the controlled release of opioids and in vivo pain killing efficacy over multiple days after a single injection will be shown. Finally, attempts to increase the sustained release time and hydrogel degradation will be addressed based on incorporation of beta-amino acid units into the peptide hydrogelators as well as the use of D-amino acids. Finally, controlled in vivo release of small molecules, peptides and proteins is demonstrated.

Rational design of peptide hydrogels for sustained drug delivery

253rd National Meeting (2017)

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