PLGA-PEG-PLGA Thermogelling polymers from PolySciTech used In Development of Hyaluronic Acid Delivery System.

Block copolymers can be used to develop thermogelling systems which are liquid at cold temperatures and turn solid when the temperature increases. One practical application of this phenomenon is drug delivery in which a cold solution of the polymer and a drug are injected into a patient and then the polymer solidifies around the drug upon heating to the patient’s body temperature (37C/98.6F) to delay and control its release rate. Recently, researchers at Rowan University used several PLGA-PEG-PLGA polymers (AK097, AK088, AK085, AK091, etc.) from PolySciTech (www.polyscitech.com) to develop a thermogelling system for the ocular delivery of hyaluronic acid. This research holds promise for the development of thermogelling drug-delivery systems. Read more: Osorno, Laura L., Daniel E. Maldonado, Ricky J. Whitener, Alyssa N. Brandley, Alex Yiantsos, Jamie DR Medina, and Mark E. Byrne. "Amphiphilic PLGA‐PEG‐PLGA triblock copolymer nanogels varying in gelation temperature and modulus for the extended and controlled release of hyaluronic acid." Journal of Applied Polymer Science (2019). https://onlinelibrary.wiley.com/doi/abs/10.1002/app.48678

“ABSTRACT: Different compositional parameters of poly(D,L‐lactic‐co‐glycolic acid)‐b‐poly(ethylene glycol) triblock copolymers (PLGA‐PEG) were varied to analyze their effect on gel formation and mechanical properties. Parameters such as hydrophilic/hydrophobic ratio (PLGA/PEG ratio), lactic acid/glycolic acid ratio (LA/GA ratio), PEG molecular weight (PEG Mw), polymer solution concentration, copolymer molecular weight (Mw), and polydispersity index (PDI) were studied in this work. For copolymers with PEG Mw of 1500 Da, gelation temperature (34–37 °C) was affected by D,L‐LA/GA ratio and Mw; while modulus was affected by LA/GA ratio, Mw, and Mn. Based on the parametric study, an injectable, thermoresponsive hyaluronic acid (HA) delivery platform was designed for ocular applications. PLGA‐PEG copolymers with D,L‐LA/GA ratio of 15/1, PLGA/PEG ratio of 2/1, PEG Mw of 1500 Da, and Mw of about 6 KDa gelled at 35 °C, were optically transparent, had a modulus less than 350 Pa and were used for HA release studies. This work also demonstrates, for the first time, an extended and controlled release of HA, beyond 2 weeks, from injectable hydrogels modified with a noncovalent interacting agent, poly(L‐lysine). Smaller PLL chains slowed down the HA release kinetics, while larger PLL chains produced a release profile similar to the nonmodified hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48678.”