Poloxamine hydrogels with a quaternary ammonium modification to improve cell attachment

✍ Scribed by Alejandro Sosnik; Michael V. Sefton

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 954 KB
• Volume: 75A
• Category: Article
• ISSN: 1549-3296
• DOI: 10.1002/jbm.a.30419

✦ Synopsis

Abstract

Four‐arm poly(ethylene oxide) and poly(propylene oxide) (PEO‐PPO) block copolymer (poloxamine, Tetronic 1107™) hydrogels were modified with positively charged groups with the aim of overcoming the low cell adhesion properties of these PEO‐rich systems. Different matrices containing poloxamine‐methacrylate (6–12%) and a quaternary ammonium methacrylate ([2‐(methacryloyloxy)ethyl]‐trimethylammonium chloride [MAETAC], 0–0.48__M__) were produced by a photo‐initiated free radical copolymerization. A sharp increase in water content for MAETAC‐containing gels was seen during the first 2 days of incubation in distilled water; some of the gels showed water uptakes as high as 12 times the initial wet weight. In phosphate‐buffered saline (PBS), this effect was less pronounced because of the decrease in the osmotic gradient. In addition, a gradual increase of both the storage and the loss modulus of the gels resulted from increasing the MAETAC content [e.g., G′ values increased from 13,500 Pa for 12% poloxamine‐methacrylate gels without MAETAC to 151,000 Pa for 0.48__M__ MAETAC contents (at 1 Hz, 100 Pa of oscillatory stress)]. Although on pure poloxamine‐methacrylate gels HepG2 and HUVEC cells attached poorly, on MAETAC‐containing specimens a well‐spread morphology and confluent monolayers were obtained, at least after preincubation in serum containing medium. Although not having all the cell compatibility of collagen, these fully synthetic quaternary ammonium‐modified PEO‐rich gels may have some utility in tissue‐engineering applications where stiff gels and cell attachment after gelation are desired. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005