Degradation Profile of Electrospun PLGA Matrix Dana Dolev1, Oded Nissan2 1 – Bio Medical Engineering Department, Tel Aviv University; 2 – Optonol Ltd. Introduction Electro spun fibers are used in various applications as scaffolds for tissue engineering; carriers for drug delivery system and wound dressing materials. Electrospinning is a polymer processing technique in which a stream of a polymer solution is subjected to a high electric field, resulting in formation of nano-micro dimension fibers. Polylactide (PLA), polyglycolide (PGA), and their copolymer polylactide-co-glycolide (PLGA) find wide applications in the pharmaceutical and medicine industries owing to their excellent biodegradation, biocompatibility and nontoxic degradation products. The degradation profile of each of these materials has great influence on their function in the medical application. The degradation is affected by many parameters. Objectives Finding raw materials for electrospun matrices that provide different degradation rates (hence fit different medical applications). Studying the effect of fiber size on the degradation of a fibrous matrix. Determining the quantitative connection between the in vitro real time and in vitro accelerated tests Understanding the quantitative connection between in vivo and in vitro degradation. Materials 1. Poly (lactide-co-glycolide acid) 75:25 ['material A'] 2. Poly (D-L-lactide-co-L-lactide acid) 50:50 ['material B'] 3. Poly (D-lactide-Glycolic acid) 60:40 ['material C'] 4.50:50 mixture of material A and material B ['material D'] 5.50:50 mixture of material A and material C ['material E'] Preparation of electrospun fiber matrix A syringe full of polymer solution was placed in the electrospinning machine. The machine was set to a voltage of 20-30kV and the elctrospun fibers were collected on a metal collector. Method #1 – In-Vitro study Performed both in a 37ºc (‘real time’) and 48ºc (accelerated) environments The samples are kept in pH controlled environment The samples are tested periodically for various parameters Method #2 – In-Vivo study Carried out on rodents’ eyes The implants are histopathologicaly evaluated periodically. Results Comparing degradation profiles of the various materials Effect of fiber size on matrix degradation profile (material ‘A’) Comparing 'real time' and 'accelerated' tests (material ‘A’) 11µm 13µm 15µm In-Vivo Study Results- Histopathological Sections 3 months – no degradation 6 months – degradation begins 12 months – full degradation Conclusions The studied materials have different degradation rates; material B has the lowest rate while material E has the highest. The fiber diameter (at the studied range) does not significantly affect the degradation profile of the matrix. The ‘acceleration factor’ obtained from this study was approx. 4 (=the degradation is 4 times faster in 48ºc than in 37ºc). The in vivo and in vitro degradation profiles of the matrix performed strong connection; The in vivo degradation is apparently slightly slower that the in vitro degradation.