Polymer graded composites for medical application
Magdalena Ziąbka, Ewa Stodolak, Jan Chłopek
Quarterly No. 2, 2009 pages 181-185
DOI:
keywords: graded composite materials, alginate, polymer degradation
abstract Functional gradation is one of characteristic feature of living tissue. Bioinspired materials open new approaches for man-ufacturing implants for bone replacement. Different routes for new implant materials are presented using the principle of functional gradation. In this paper an artificial biomaterial for bone replacement has been developed by building a graded structure consisting of resorbable polymer matrix modified with biopolymer powder. For preparation graded materials with different in situ porosity and in vitro durability diversification biopolymer in form of sodium alginate (NaAlg, powder) was in-troduced into resorbable polymer matrix of lactide-coglicolide (PGLA). Than composite films were cast from polymer solution with deferent mass fraction of modifier (727%). On the basis of degradation tests (durability in in vitro conditions), pro-file measurements, mechanical tests and microscopic observations composite structures (cubical shape with different arrangement of composite layers) were designed. Two types of porosity gradients were obtained. These graded materials with different mass fraction of sodium alginate were investigated during the durability tests in Ringer solution. Degradation degree was defined on the basis of velocity changes of the ultrasonic wave and pH of the immersion medium. It was found that com-posite degradation rate depends on porogene mass fraction and it was also connected with its arrangement way in polymer matrix.