Effect of some additives on the biostability of a poly(etherurethane) elastomer

Abstract

Four materials based on a single poly-(etherurethane) (PEU) prepared from MDI and PTMEG but differing in additives were studied in the cage implant system. The two additives studied were Santowhite powder at the 1% level and Methacrol 2138F 5%. Methacrol 2138F appeared to be immiscible with the base PEU and was dispersed in discrete domains about 0.5-micron in size. The retrieved PEU specimens were also cleaned and examined in the optical and scanning electron microscopes, and the size and density of adherent foreign body giant cells (FBGCs) were measured at implantation times up to 10 weeks. Methacrol 2138F had no effect on the density, coverage or size distribution of adherent FBGCs, but leaching of Methacrol 2138F was considered to be responsible for extensive pitting of the PEU surface. On the other hand, Santowhite powder appeared to inhibit formation of FBGCs, and while surface cracking and flaking were observed as early as 3 weeks postimplantation on some PEUs, the Santowhite powder effectively inhibited surface cracking and flaking up to the longest implantation time studied.

In vivo biocompatibility and biostability of modified polyurethanes

“…Although SPU-S also contains additives, this is not expected to influence cell adherence. 4 In contrast, the polycarbonate polyurethanes (SPU-PCU and SPU-C) tended to have lower macrophage densities up to 5 weeks than the polyether polyurethanes (PEUU AЈ and SPU-PRM). FBGC densities were lower at 3 and 5 weeks for the polycarbonate polyurethanes.…”

“…In order to reduce the oxidation of the soft segment, antioxidant additives, such as Santowhite and others, have been used. 3,4 Modifications or substitutions of the soft segment have been made to enhance biostability. The soft segment chemistries have been varied by substituting the polyether segment with a polybutadiene, polydimethylsiloxane (PDMS), 5 polycarbonate, [6][7][8][9][10][11] and aliphatic hydrocarbon segment.…”

Biocompatible Polyamides and Polyurethanes Containing Phospholipid Moiety

“…However, the blood compatibility of segmented polyurethane is not enough to be applied for longterm implantation. It has been suggested that the biodegradation and cracking of polyurethane occurred in vivo due to the adsorption of proteins, the adhesion of macrophages and the peroxide formation (Zao et al, 1991(Zao et al, , 1993Wu et al, 1991), which resulted in the reduction of the mechanical strength of SPU. Moreover, it was reported that the soft segment of segmented polyurethane was degraded by the oxygen radicals produced from adherent macrophages (Stokes et al, 1995).…”

Synthesis and Properties of Segmented Poly(urethane-urea)s Containing Phosphorylcholine Moiety in the Side-Chain

“…Hydroxyethoxypropyl-terminated polydimethylsiloxane (HO-PDMS, M n ¼ 1;000) was purchased from Chisso Corporation and used as received. 4,4 0 -Diphenylmethane diisocyanate (MDI), 1,4-butanediol (BD) and dibutyltin dilaurate (DBTDL) were purchased from Tokyo Kasei Chemical Co. Ltd. and used as received. Other chemicals were used without further purification.…”

“…However, the blood compatibility of SPU is not enough to be applied for long-term implantation. It has been suggested that the biodegradation and cracking of the SPU occurred in vivo due to the adsorption of proteins, the adhesion of macrophages and the peroxide formation, [3][4][5] which resulted in the reduction of the mechanical strength of SPU. Moreover, it was reported that the soft segment of SPU was degraded by the oxygen radicals produced from adherent macrophages.…”