Polyethylene glycol‐based cationically charged hydrogel beads as a new microcarrier for cell culture

Abstract A new polyethylene glycol (PEG) based microcarrier was designed and examined by the attachment and growth of mouse fibroblast cells. In the design of microcarrier, a PEG‐based macromonomer, polyethyleneglycol methacrylate (PEGMA), was selected as the main component of hydrogel beads since PEG is known as a nontoxic and biocompatible material. A relatively new cationic comonomer, N‐[3‐(dimethylamino)propyl]methacrylamide (DMAPM), with higher ionization ability with respect to the similar comonomers was used for providing cationic charge to the hydrogel structure. In the first part, a suspension copolymerization method was developed for the production of cationically charged hydrogel beads as a potential microcarrier for cell culturing. The suspension copolymerization by using ethylene dimethacrylate (EDM) as cross‐linking agent and cyclohexanol as the diluent provided spherical, polydisperse poly(PEGMA‐DMAPM‐EDM) hydrogel beads with an average size of 121 μm. The hydrogel beads exhibited a pH‐dependent swelling behavior. The L929 mouse fibroblast cells were cultured on poly(PEGMA‐DMAPM‐EDM) hydrogel beads with an initial concentration of 200,000 cells/mL. The cells were incubated in Dulbecco's modified Eagle's medium during 5 days and the cell proliferation was investigated at every 24 h. An effective cell attachment and growth up to 3.5 × 10⁶ cells/mL were observed with the poly(PEGMA‐DMAPM‐EDM) hydrogel beads. The results indicated that the proposed microcarrier was a significant alternative to the hydrogel beads obtained by the copolymerization of 2‐hydroxyethyl methacrylate and 2‐dimethylaminoethylmethacrylate commonly used in microcarrier‐facilitated cell culturing studies. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007