Dosimetric Double Network Hydrogel Based on Poly(vinyl-alcohol)/Phenylalanine-Derivatives with Enhanced Mechanical Properties

An innovative double network hydrogel based on poly(vinyl-alcohol) (PVA) cross-linked with glutaraldehyde (GTA) was obtained by the addition of self-assembling phenylalanine (Phe) derivatives with the aim to achieve improved mechanical-elastic properties exploitable to produce 3D dosimeters. The self-assembling ability in fibrous structures of Phe derivatives (FmocPhe-OH, A; FmocPhe-Phe-OMe, P) even within the PVA gel was proved by AFM and SEM imaging. The proposed matrices containing A and P were completely characterized from the physical-chemical point of view in order to deeply understand how the two molecules influenced the hydrogel properties. Mechanical tests proved that the addition of the Phe derivatives produce higher stiffness, toughness, and stretchability of the hydrogels. In particular, these properties appear in the peptide P matrix and could be appropriately tailored by regulating the concentration of the added molecule. Preliminary dosimetric studies were also performed by infusing the studied hydrogels with Fricke solution. The P type has been demonstrated to be suitable for dosimetric applications by avoiding any effect on the dose response of the hydrogel. This work presents an unconventional material that is able to provide clinicians and medical physicists with effective and reliable 3D dosimetric measurements for the development of anthropomorphic phantoms that mimic mechanical properties and the radiological response of human tissues.