ISSN:
0021-9304
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
,
Technology
Notes:
The bone-bonding polymer known as Polyactive® is a block copolymer composed of a polyethylene oxide (PEO) soft segment and a polybutylene terephthalate (PBT) hard segment. This study focuses on the in vitro induction of hydroxyapatite by Polyactive®. Our results show that Polyactive® is capable of inducing hydroxycarbonate apatite (HCAp) formation from a metastable calcium phosphate solution analogous to a physiological solution. In a 4-day incubation, the HCAp formation extended approximately 100 μm deep from the surface. A great number of globules about 1 μm large were found in the calcified Polyactive®. These globules were composed of HCAp crystals embedded in the polymer matrix. There were so many globules in the surface that they connected with each other and formed a calcified layer. Next to the calcified layer was a zone where the globules were scattered. The calcified surface may have acted to promote HCAp growth from the solution, bringing about the formation of a HCAp layer on top of the calcified layer. The transition of solid Polyactive® into a Polyactive® hydro-gel in calcium phosphate solution permitted HCAp formation within the polymer. It is proposed that the COOH groups produced during hydrolysis of Polyactive® play an important role in nucleating hydroxyapatite. A remarkable affinity of the PEO segment of the polymer for calcium ions may facilitate moving calcium and phosphate from the solution into the polymer for the growth of HCAp. © 1997 John Wiley & Sons, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
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