Development of Biodegradable Polymers Poly(?-amino ester) and Poly(lactic-co-glycolic acid) for the Controlled Release of Bupivacaine

This project explores the potential of a poly(β-amino ester) (PBAE) encapsulated poly(lactic-co-glycolic acid) (PLGA) system to serve as an extended drug delivery method for local anesthetic-bupivacaine. This research addressed the need to provide a longer-lasting pain management regimen for patients and to also develop an alternative to opioids, commonly used medicine for pain management, and the risks that come with prescribing them. This project investigates a new system for controlled release of bupivacaine for 48 hours. To make the PBAE hydrogel, PBAE macromer was first synthesized by reacting diethylene glycol diacrylate (DEGDA), polyethylene glycol 400 diacrylate (PEG400DA), and isobutylamine. Next, a solution of ethanol and the photoinitiator 2,2-dimethoxy-2-phenylacetophenone (DMPA) was added and mixed with the macromer. This mixture was then injected into two parallel glass plates and exposed to a UV flood source to form the PBAE hydrogel. The PBAE hydrogels were characterized by conducting a swelling study and degradation study. PBAE hydrogel was cut into circular chunks, soaked in a bupivacaine-in-ethanol solution. Then to make microparticles, bupivacaine loaded hydrogels were grounded and passed through a sieve. Then the microparticles were encapsulated in PLGA, and in vitro drug release study was conducted in PBS buffer. It was found that PBAE encapsulated in PLGA system could release bupivacaine for 48 hours and with less initial burst release compared to the PBAE or PLGA alone. The PBAE-PLGA based drug release system shows potential and could be further improved for the desired outcome.