Journal of Biomedical Materials Research · 1985 · 373 citations · 11 references
Natural SciencesBioengineeringBiomedical EngineeringBiocompatibilityBiomaterialsPolymer ChemistryBiodegradable BiomaterialsBiodegradable PolymersBiodegradationDegradation ProductsPolymer DegradationPolymeric BiomaterialsAliphatic Polyester BiodegradationDegradationPolycaprolactonePolycaprolactone DegradationPolymer Degradation KineticsPolymer Degradation MechanismsPolymeric Matrix DegradationSoft Gelatin Capsules
Poly(ε‑caprolactone) (PEC) is a biodegradable aliphatic polyester that degrades in two stages: an initial nonenzymatic hydrolytic cleavage of ester groups, followed by a second phase that begins when the polymer becomes highly crystalline and low molecular weight. The second phase was investigated by implanting gelatin capsules containing 25 mg of low‑molecular‑weight (Mn ≈ 3000) PEC powder (106–500 µm) into rats. PEC fragments were degraded within macrophage and giant cell phagosomes in less than 13 days at some sites, were also found in fibroblasts, and these results confirm that intracellular degradation is the main pathway once the polymer’s molecular weight falls to 3000 or below.
Abstract Poly(ε‐caprolactone) [PEC], a biodegradable aliphatic polyester, undergoes a two‐stage degradation process: The first lengthy phase involves nonenzymatic hydrolytic cleavage of ester groups, the second phase beginning when the polymer is more highly crystalline, and of low molecular weight. The cellular events of the second phase were examined by implanting gelatin capsules containing 25 mg of low molecular weight ( M n 3000) PEC powders, 106 to 500 μm, in rats. PEC fragments ultimately were degraded in phagosomes of macrophages and giant cells, the process requiring less than 13 days for completion at some sites. PEC was also identified within fibroblasts. These studies support the intracellular degradation of PEC as the principal pathway of degradation once the molecular weight of the aged polymer is reduced to 3000 or less.
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