title: Influence of electron-beam radiation on the hydrolytic degradation behaviour of poly(lactide-co-glycolide) (PLGA).
abstract: The purpose of this study is to examine the effect of electron-beam (e-beam) radiation on the hydrolytic degradation of poly(lactide-co-glycolide) (PLGA) films. PLGA films were irradiated and observed to undergo radiation-induced degradation through chain scission, as observed from a drop in its average molecular weight with radiation dose. Irradiated (5, 10 and 20 Mrad) and non-irradiated (0 Mrad) samples of PLGA were subsequently hydrolytically degraded in phosphate-buffered saline solution at 37.0 degrees C over a span of 12 weeks. It was observed that the natural logarithmic molecular weight (lnMn) of PLGA decreases linearly with hydrolytic degradation time. The rate of water uptake is higher for samples irradiated at higher radiation dose (e.g. 20 Mrad) and subsequently causing an earlier onset of mass loss. It is postulated that the increase in water uptake is due to the presence of more hydrophilic end groups, which results in the formation of microcavities because of an increase in osmotic pressure. A relationship between radiation dose and the rate of hydrolytic degradation of PLGA films, through its molecular weight was also established. This relationship allows a more accurate and precise control of the life span of PLGA through the use of e-beam radiation.
authors.affiliation: School of Materials Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Say Chye Joachim
authors.initials: SC
authors.lastname: Loo
authors.forename: Chui Ping
authors.initials: CP
authors.lastname: Ooi
authors.forename: Yin Chiang Freddy
authors.initials: YC
authors.lastname: Boey
mesh_terms: D020341:Absorbable Implants; D000042:Absorption; D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects*; D001826:Body Fluids / Q000737:chemistry; D004307:Dose-Response Relationship, Radiation; D004583:Electrons; D006868:Hydrolysis; D019344:Lactic Acid / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects*; D008422:Materials Testing / Q000379:methods*; D008970:Molecular Weight; D010539:Permeability / Q000528:radiation effects; D011100:Polyglycolic Acid / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects*; D016062:Porosity / Q000528:radiation effects; D011829:Radiation Dosage; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid