Effect of phenylalanine derivatives on dosimetric and mechanical properties of innovative PVA hydrogel matrices for external radiation therapy.

Fricke gel (FG) were improved by the addition of self-assembled phenylalanine derivatives which favor the formation of fibrous structure network that fills the porosity of the Polyvinyl alcohol (PVA) matrix and, consequently, increases the hardness and the elastic properties of the gel. This advancement would make it possible to produce anthropomorphic phantoms with an elasticity comparable to various soft tissues of the human body, allowing the dosimetric verification of sophisticated radiotherapy treatments also for organs subjected to natural movement ($i.e.$, breathing). The self-assembly ability of peptides inside the gel is evaluated and a complete characterization of the new matrix is provided. Moreover, mechanical tests have shown that the addition of the peptide led, with respect to the common FG, to higher stiffness, toughness and stretchability of the hydrogels and that the matrix can be appropriately tailored by regulating the amount of the added peptide. The basis for a possible dosimetric characterization in a pre-clinical scenario will be laid.