Traditional stents permanently impair normal vascular function and lead to late complications like neoatherosclerosis and stent failure. Bioresorbable scaffolds (BRS) is a promising emerging technology developed to provide similar mechanical support, while dissolving over time to restore vasomotion and endothelial function and reduce very late events. BRSs are typically made of polymers, most commonly poly-L-lactic acid (PLLA). Modelling material properties throughout degradation correctly is essential for adequate BRS design and simultaneous prediction of BRS degradation process and vessel healing. In earlier studies, mathematical model of influence of constant deformation on degradation has been proposed, however, it does not address the varying deformation, and it has not been experimentally validated [1]. Experiments have been conducted to examine the effects of degradation of unloaded poly-lactic acid (PLA) in various environmental conditions on mechanical properties [2]. Creep test on PLLA in phosphate buffered solution (PBS) under constant load has been performed, however, the mechanical properties at various stages of degradation have not been examined [3]. Overall, limited knowledge exists regarding the impact of variable mechanical loads on PLLA degradation in BRS conditions. In this study, the effect of different constant and varying deformations on degradation of PLLA in PBS at blood vessel temperature of 37°C will be experimentally determined. Additively manufactured PLLA samples will be extended at various elongations. The samples will be taken out at set time intervals. Between the intervals, some samples will have their elongation changed to a different fixed elongation, whereas others will undergo degradation under constant elongation. Mass change will be measured, and uniaxial tensile test will be performed to determine mechanical properties. The study will give a better understanding of evolution of mechanical properties of PLLA undergoing degradation under load.