Development of PVA/Fe3O4 as Smart Magnetic Hydrogels for Biomedical Applications

Polyvinyl alcohol (PVA)/Fe 3 O 4 magnetic hydrogels had been fabricated by freezing- thawing (F-T) cycle technique, employing natural iron sand as the raw material for the magnetic micro- and nano-sized fillers. An exploration of the durability and magneto - elasticity as well as PVA hydrogel applications in the assessment of human brain tumor was also intensively conducted. The performance of the PVA and magnetic hydrogels mainly depends on the structural dynamic properties, such as polymeric crystallization and particle size. The durability of PVA/Fe 3 O 4 magnetic hydrogels affecting the magne - toelasticity is determined by the concentration ratio of PVA and water, number of F-T cycles, and the concentration of Fe 3 O 4 particles. By controlling those parameters, it was found that hydrogels had PVA: water ratio of 23:100 and four times F-T cycles possessed good mechanical properties. Due to the biocompatible character, the PVA hydrogel was used in the assessment of the human brain tumor, analyzed from the apparent diffu sion coefficient (ADC) value representing the diffusion coefficient of a biological tissue. It was found that the abnormal tissue has a low ADC value compared with the normal one. Moreover, the higher b-value of the diffusion-weighted magnetic resonance imag - ing (DW-MRI) measurement is more preferred in obtaining a good contrast of the data imaging. were conducted to analyze the crystal structure and particle morphology of Fe 3 O 4 nanoparticles and ferrogels, respectively. Vibrating sample magnetometer (VSM) and superconducting quantum interference device (SQUID) measurements were taken to inves tigate the magnetic properties of the PVA ferrogels. Particle size and the distribution of Fe 3 O 4 nanoparticles in the PVA hydrogels were analyzed using small-angle X-ray scattering (SAXS) instrument as in the reported paper [48 ].