Filler materials for medical use present limits, such as the induction of chronic
inflammation and
fibrosis. In the search for synthetic materials with improved biocompatible properties, a new
polyacrylamide hydrogel,
Aquamid (Contura SA, Montreux, Switzerland), has been investigated in preclinical systems. In cell cultures (endothelial cells and fibroblast), no or only transient
biological effects were associated with 10%
Aquamid exposure. The
Aquamid-host interactions were examined in mice (10 mice per group) implanted subcutaneously or in the mammary fat pad with a very large volume (1.5 ml) of the material. Blood analysis, performed after 15 and 94 days (five mice per time for each group) to detect acute or late manifestations of toxicity, did not reveal relevant abnormalities in either group of
Aquamid-bearing mice compared with control mice, except for a transient
thrombocytopenia and a mild
leukocytosis. Histological analysis of the pellet showed the presence of a thin, poorly vascularized
cyst wall in implants. Only mild mesenchymal reparative and inflammatory processes were observed, even at longer observation times (more than 400 days). No alterations in any organ were detected. Despite the large volume implanted (approximately 5 percent of mouse
body weight), the
Aquamid pellet maintained its original size and shape without spreading or sticking to surrounding tissues. In conclusion, the study indicated a good tolerability of the new
biopolymer in preclinical systems. The clinical utility of this new compound, if confirmed by clinical randomized trials showing its atoxic properties, could be in the field of aesthetic plastic surgery as a filler material for
body contouring and in reconstructive surgery and above all in
cancer patients to restore surgical defects.