title: Long-term implantation test and tumorigenicity of polyvinyl alcohol hydrogel plates.
abstract: Two types of flat plates made from a polyvinyl alcohol (PVA) hydrogel with a water content of 80 and 20 (PVA-H80, PVA-H20), 20 x 10 x 1 mm in size, were subcutaneously implanted into each of 50 young, male Wistar rats. As a control, a sham operation was done on another set of 50 rats (Sham Op group). The shape and transparency of the PVA hydrogel were unchanged for up to 24 months. Tumors arose in 14 rats from the PVA-H80 group. In the PVA-H20 group, tumors appeared in 15 rats. The average tumor latency was 598 +/- 109 days in the PVA-H80 and 637 +/- 94 days in the PVA-H20. There was no difference in tumor incidence between the PVA-H20 and PVA-H80 groups (p < 0.05). In the Sham Op group, no malignant tumors appeared. Histopathologically, the tumors induced by hydrogel plates were malignant tumors resembling fibrosarcoma or malignant fibrous histiocytoma. This indicates that PVA hydrogel implants also induce solid state carcinogenesis at a similarly high rate to medical grade hydrophobic material reported in a previous study.
authors.affiliation: Department of Bioartificial Organs, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-yu, Kyoto 606-8507, Japan. nakamura@frontier.kyoto-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: H
authors.initials: H
authors.lastname: Ueda
authors.forename: T
authors.initials: T
authors.lastname: Tsuda
authors.forename: Y H
authors.initials: YH
authors.lastname: Li
authors.forename: T
authors.initials: T
authors.lastname: Kiyotani
authors.forename: M
authors.initials: M
authors.lastname: Inoue
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: T
authors.initials: T
authors.lastname: Sekine
authors.forename: L
authors.initials: L
authors.lastname: Yu
authors.forename: S H
authors.initials: SH
authors.lastname: Hyon
authors.forename: Y
authors.initials: Y
authors.lastname: Shimizu
mesh_terms: D020341:Absorbable Implants / Q000009:adverse effects*; D000818:Animals; D001672:Biocompatible Materials / Q000493:pharmacokinetics* / Q000633:toxicity*; D015197:Carcinogenicity Tests; D005500:Follow-Up Studies; D020100:Hydrogels / Q000737:chemistry; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D011142:Polyvinyl Alcohol / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D014867:Water; D011142:Polyvinyl Alcohol