Degradation of electrospun poly(L‐lactide) membranes under cyclic loading

Abstract

Because of the great effect of mechanical loads on degradation of biodegradable biomaterials, investigation on degradation of electrospun membranes under dynamic loading is of importance. In this article, degradation of electrospun poly(L-lactide) (PLLA) membranes was carried out in a Tris-HCl buffer solution containing proteinase K under a cyclic stretch loading (dynamic condition) in comparison with that in shaking water bath (static condition). The evolutions of mass loss, morphology, thermal properties, and relative molecular weight of PLLA were monitored during degradation. The results showed that after degradation for 10 h, the mass of the electrospun PLLA membranes dropped by 38.7% and 31.3%, respectively, under dynamic and static conditions. And the electrospun PLLA membranes showed higher value of crystallinity during degradation under both cyclic loading and static condition. In addition, benzyl triethyl ammonium chloride (BTEAC) was introduced during electrospinning, and the effects of electrospun membranes characteristic and crystallinity on degradation were also investigated. The degradation study results are expected to be a basic study in mimicking actually mechanical environments. V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 124: E258-E266, 2012

Effects of external stress on biodegradable orthopedic materials: A review

“…This rate reduction arises from collapse of the pores in the implant due to dynamic compression loading. Another study [87] shows that cyclic compression does not affect degradation of PLLA in the early period, but promoted degradation is observed afterwards, suggesting that the influence of dynamic compression stress is related to the geometry of the specimens and the influence is more apparent in the later immersion stage. It should be mentioned that dynamic compression leads to enhanced fluid flow in and out of the specimen [89] consequently enhancing diffusion of small molecules and causing mass losses.…”

The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters

“…Moreover, changes in their molecular weight, thermal properties, lactic acid release and morphology property indicted the tensile loading accelerate the degradation rate. In addition, Zhao et al [ 90 ] reported the accelerated degradation of electrospun PLLA membranes when subjected to the cyclic stretch loading in Tris-HCl buffer solution containing proteinase K. Furthermore, a quantitative investigation of the tensile stress and in vitro degradation rate of PLGA membranes has been conducted by Guo et al [ 91 ]. Tensile stress in levels of 0.1–0.5 MPa and deionized water was applied.…”