Four Year Absorption Study of Three Morphologically Different Forms of Poly-L-Lactide in Rabbits
The rate of absorption of Poly-L-Lactide (PLLA) in the body, among other factors, is influenced by its morphology. In this study the absorption of implants made from three distinctly different morphological forms of PLLA, was investigated in rabbits. The three morphological forms of PLLA studied were mostly amorphous, mostly crystalline, and orientruded (extruded and drawn). Mostly amorphous and mostly crystalline PLLA implants were placed surgically in the lumbar muscles and orientruded PLLA implants were placed in the femoral intra-medullary canal of the rabbits. Molecular weight degradation and loss of mass of these implants were monitored as a function of time of implantation. The molecular weight of all three forms of PLLA implants was substantially degraded in the initial six months of implantation. There was no significant difference in the degradation rate of molecular weight of these three forms of PLLA among one another. However the rate of absorption of each form of PLLA was significantly different from the other two forms. Orientruded PLLA had the most rapid absorption and mostly crystalline PLLA was the slowest to absorb. At the four year time period both orientruded and mostly amorphous PLLAs were completely absorbed and only 77% of the mostly crystalline PLLA was absorbed.
KeywordsInjection Molding Implantation Site Morphological Form Inherent Viscosity Relative Crystallinity
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- 1.D. C. Tunc and B. S. Jadhav, in: Progress in Biomedical Polymers C. G. Gebelein and R. L. Dunn, Eds., Plenum Press, New York, 1990, P. 239.Google Scholar
- 2.D. C. Tunc, M. W. Rohovsky, B. S. Jadhav, W. B. Lehman, A. Strongwater and F. Kummer, in: Advances in Biomedical Polymers C. G. Gebelein, Ed., Plenum Press, New York, 1987, p. 87.Google Scholar