Preparation and characterization of pH-sensitive hydrogel for drug delivery system

Abstract

In this paper, a new kind of pH-sensitive hydrogel based on poly(lactic acid) (PLA), methoxyl poly(ethylene glycol) (MPEG) and itaconic acid (IA) was prepared by heat-initiated free radical polymerization method without any organic solvent. The obtained macromonomers and hydrogels were characterized by ¹H NMR and FTIR. Detailed swelling behavior of hydrogels under variational pH-conditions revealed that the dynamic sensitivity of P(MPEG-PLA-co-IA-MEGMA) hydrogels [P(LE-IA-MEG) hydrogels] as well as the diffusional mechanisms might be causing the network expansion and collapse. In vitro drug release behavior was investigated using VB₁₂ and paclitaxel (PTX) as model drugs, revealing that the P(LE-IA-MEG) hydrogel could control the diffusion of the drug. The prepared new kind of pH-sensitive hydrogel with great pH-responsiveness and good properties for drug delivery might have great potential application in smart drug delivery systems.