Lactide and Glycolide Polymers

Biodegradable polymers based on lactide, glycolide, and e-caprolactone are widely used in biomedical research such as tissue engineering and drug delivery systems. These biomaterials possess excellent tissue compatibility and safety profile in the human body.1,2

Polylactide(PLA) is synthesized via ring-opening polymerization of lactic acid dimers (lactide rings) which contain two optical isomers, referred to as D-lactide or L-lactide. Poly(L-lactide) (PLLA) is a semicrystalline polymer exhibiting a high modulus and a slow degradation time (more than 24 months); whereas poly(D,L-lactide) (PDLLA) is amorphous and has a low modulus and a more rapid degradation time (12 to 16 months) which makes it more suitable for drug delivery systems.

Additionally, lactide-based biodegradable copolymers with glycolide and e-caprolactone have been employed to meet specific needs in biomedical applications. These copolymers have a wide range of properties and applications, depending on the feed ratio of lactide to the other monomer. For example, poly(lactide-co-glycolide) (PLGA) reduces stiffness compared with pure polyglycolide (PGA) and offers faster degradation time than each homopolymer. Polycaprolactone (PCL) is a semicrystalline elastic material, but it degrades slower than PLA. Therefore, poly(lactide-co-caprolactone) (PLCL) is softer than PLA and accelerates the degradation time. The properties can be tuned over a wide range to meet the needs of a given application.

References:

1. Huayu Tian, Zhaohui Tang, Xiuli Zhuang, Xuesi Chen, and Xiabin Jing, “ Biodegradable Synthetic Polymers: Preparation, Functionalization and Biomedical Application” Progress in Polymer Science, 2012, 37(2), 237-280.
2. Anna Musyanovych and Katharina Landfester, ”Biodegradable Polyester-based Nanoparticle Formation by Miniemulsion Technique” Material Matters, 2012, 7(3), 30-32.