Influence of Radiation Sterilization on Properties of Biodegradable Lactide/Glycolide/Trimethylene Carbonate and Lactide/Glycolide/ε-caprolactone Porous Scaffolds with Shape Memory Behavior

Abstract

The aim of the study was the evaluation of gamma irradiation and electron beams for sterilization of porous scaffolds with shape memory behavior obtained from biodegradable terpolymers: poly(l-lactide-co-glycolide-co-trimethylene carbonate) and poly(l-lactide-co-glycolide-co-ɛ-caprolactone). The impact of mentioned sterilization techniques on the structure of the scaffolds before and after the sterilization process using irradiation doses ranged from 10 to 25 kGy has been investigated. Treatment of the samples with gamma irradiation at 15 kGy dose resulted in considerable drop in glass transition temperature (Tg) and number average molecular weight (Mn). For comparison, after irradiation of the samples using an electron beam with the same dose, no significant changes in structure or properties of examined scaffolds have been noticed. Higher doses of irradiation via electron beam caused essential changes of the scaffolds’ pores resulting in partial melting of their surface. Nevertheless, obtained results have revealed that sterilization with electron beam, when compared to gamma irradiation, is a better method because it does not affect significantly the physicochemical properties of the scaffolds. Both used methods of sterilization did not influence the shape memory behavior of the examined materials.

Influence of electron beam irradiation on extracellular matrix of the human allogeneic skin grafts

“…11,20,30 In this manner many authors recommend the electron beam radiation sterilization as the most suitable method for sterilization of biological collagenous materials. [19][20][21] There is also a number of literature reports on effective e-beam sterilization of the biological materials such as skin, bone, amniotic membrane, and so on 1,[3][4][5][6]11,20 as well as synthetic biomaterials, for example, porous terpolymer scaffolds with shape memory, 31 terpolymer implantable drug delivery systems, 32,33,34 polyethylene implants, 35 and so on. However, there are still a number of doubts and concerns as electron beams may cause damage to the structure of the graft and hence worsen its mechanical properties.…”

Sterilization of Polymeric Implants: Challenges and Opportunities

“…From a technical viewpoint, however, drawbacks of these irradiation methods can be extensive depending on the polymer in question. For example, the high energy from γ rays is capable of inducing polymer chain scission (e.g., via C−C bond cleavage in even chemically stable polymers) and cross-linking (by radical recombination), 29,33,47,48 conferring changes in polymer molecular weight, 49,50 packing crystallinity, 49 mechanical integrity, 22,29,50,51 degradation rate, 33,50,51 porosity, 34,40,50 and thermosensitive behavior. 33,50 For instance, increased cross-linking of UHMWPE postgamma irradiation could result in increased strength but decreased wear resistance, 22 while the reduced molecular weight of polylactide could expedite degradation.…”

Shape-Memory Polymers Hallmarks and Their Biomedical Applications in the Form of Nanofibers

“…Rychter et al evaluated the effect of gamma irradiation (in the range from 10 to 25 kGy) for sterilization of porous scaffolds with shape-memory behavior obtained from biodegradable terpolymers: poly(l-lactide-co-glycolide-co-trimethylene carbonate) and poly(l-lactide-co-glycolide-co--caprolactone) [110]. Treatment of the samples with gamma irradiation at 15 kGy resulted in a considerable drop in glass transition temperature (T g ), decrease in average molecular weight (M n ) and in scaffolds' mechanical properties.…”