Effect of polyethylene glycol concentration on the viability and morphology of osteoblasts and fibroblasts.

This article focuses on the effects of polyethylene glycol (PEG), a polymer commonly regarded as bio-inert, on the viability and morphology of osteoblasts and gingival fibroblasts in vitro. The study demonstrates that PEG (molecular weight 2000 g/mol) interacts with extracellular carbon dioxide (CO2), disrupting the bicarbonate buffering system in Dulbecco's Modified Eagle's Medium (DMEM) and causing an increase in medium pH. This alkalization enhances cell viability but also induces morphological changes indicative of cellular stress, such as membrane blebbing and rounding, with effects modulated by PEG concentration and the presence of the HEPES buffering agent. These findings suggest that PEG's influence on microenvironmental pH dynamics challenges its classification as a passive biomaterial and highlights the importance of optimizing PEG concentration and buffering conditions to balance biocompatibility and cellular health in tissue engineering applications.