Poly(vinyl alcohol co-vinyl acetate) as a novel scaffold for mammalian cell culture and controlled drug release

Tissue engineering requires novel smart materials to sustain cell growth, tissue regeneration and in situ drug release in a controlled mode. Also, biocompatible synthesis methods are needed to immobilize biologically active compounds. Poly(vinyl alcohol co-vinyl acetate) (PAcVA) was synthesized at 37 °C using glutaraldehyde (GA) as a crosslinking agent. The mechanical characteristics of the polymer were manipulated by varying crosslinking degrees using different GA concentrations. Materials with Young’s modules similar to soft tissues, adequate for tissue engineering, were obtained. PAcVA was a pH-responsive material with maximum swelling at pH 5.8. When hydrated, PAcVA was electro-responsive. Fluorescein was used as a model molecule to characterize the releasing properties of the polymer. Effective diffusivities were a function of the crosslinking degree. Release rates were proportional to temperature and were faster at lower GA contents. According to a fit to the Korsmeyer–Peppas’ model, diffusion at 5 and 10% GA was Fickian, but at 20% GA, diffusion was abnormal. To promote cell attachment and neutralize free aldehyde groups, PAcVA hydrogels were covered with poly-l-lysine and laminin, which supported growth of lung carcinoma and mouse hypothalamic cells without signs of cytotoxicity or oxidative stress. An intelligent low-cost hydrogel with properties that can be easily modulated was synthesized and fully characterized. Its properties make it suitable for tissue engineering applications, as they mimic the mechanical properties of natural tissues.