Ibuprofen‐Functionalized Poly(β‐Amino Ester)‐Based Crosslinkers for Controlled Delivery From Gels

A novel poly(β‐amino ester) (PBAE)‐based gel is prepared as a delivery system for Ibuprofen (IBU) to reduce the systemic dosage of IBU through release at the target site. First, a water‐soluble PBAE macromer (PEGAP) is synthesized through aza‐Michael addition of 5‐amino‐1‐pentanol to poly(ethylene glycol) diacrylate (PEGDA, M n = 575 D). Then, PEGAP is functionalized with IBU using the ionic interaction of PBAE with Ibuprofen‐sodium salt to give three macromers (PEGAP‐IBU) at different IBU concentrations. Polymerization rates and conversions of the macromers are monitored during their copolymerizations with PEGDA using photo‐DSC. The macromers are incorporated in PEGDA and PEGDA:trimethylolpropane triacrylate to obtain gels whose biodegradation and release properties are studied. The gels are found to reach 50%–100% degradation in 1 day, depending on the amount of PEGAP‐IBU incorporated in gels. The PEGAP‐IBU incorporating gels show slower IBU initial release profiles than similar gels encapsulating small‐molecule IBU at pH 7.4. The anti‐inflammatory effect of PEGAP‐IBU on the RAW 264.7 cells is found to be similar to commercial IBU, with nitrite inhibition percentages of 50.42 and 50.54 for PEGAP‐IBU and IBU. These crosslinkers have the great potential of polymer‐drug gels in improving the drug delivery systems.