Investigating the Interactions of Peptide Nucleic Acids with Multicomponent Peptide Hydrogels for the Advancement of Healthcare Technologies

This study investigates the use of peptide-based hydrogels as scaffolds for the encapsula-tion and delivery of Peptide Nucleic Acids (PNAs) in drug delivery applications. Ultra-short aromatic peptide-based hydrogels (HGs), such as Fmoc-FF (Nα-fluorenyl methox-ycarbonyl-diphenylalanine), provide an ideal platform for encapsulating biomolecules due to their biocompatibility, self-assembling nature, and ability to form stable, nanostructured networks. The functionalization of these hydrogels with Fmoc-FFX tripep-tides—where X is cysteine (C) or lysine (K)—enhances their ability to interact with PNA sequences. Model four-bases PNA, functionalized with cysteine (C) or glutamic acid (E) residues at the C-terminus, facilitate covalent or electrostatic interactions with the hydro-gel matrix, improving encapsulation efficiency and stabilizing the PNAs. We systemati-cally optimized the composition and ratios of hydrogel components and PNAs to enhance encapsulation efficiency, structural stability, and controlled release profiles. The resulting hydrogels were thoroughly characterized using High-Performance Liquid Chromatog-raphy (HPLC), Electrospray Ionization Mass Spectrometry (ESI-MS), Circular Dichroism (CD), rheology, Fourier-Transform Infrared (FT-IR) spectroscopy, Scanning Electron Mi-croscopy (SEM), Proton Nuclear Magnetic Resonance (¹H-NMR), as well as optical and fluorescence microscopy. Our results demonstrate the potential of these hydrogels as highly effective platforms for stabilizing and delivering PNAs, offering promising pro-spects for the development of innovative nucleic acid-based therapies.