Bioinspired phospholipid polymer hydrogel system for cellular engineering

The properties of the microenvironment surrounding cells are important for the control of cell functions. The polymeric cellular environment has great potential in this regard because environmental properties can be manipulated. We propose a spontaneously forming phospholipid polymer hydrogel system composed of 2 kinds of pre-polymers to control cellular functions via hydrogel physical properties. These pre-polymers are cytocompatible poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate-co-p-vinylphenylboronic acid) (PMBV) and water-soluble poly(vinyl alcohol) (PVA). The p-vinylphenylboronic acid units in PMBV can react with the hydroxy groups of PVA in aqueous medium and form cross-linkages. This spontaneously formed PMBV/PVA hydrogel can be dissociated again via the addition of sugar compounds. To alter the physical properties, we simply change the concentration or mixing ratio of the pre-polymers. The storage modulus of the PMBV/PVA hydrogel matrix was controlled from 0.3 kPa to 2.5 kPa, which corresponds to very soft natural tissue. Cells can be encapsulated in the hydrogel. When the storage modulus of the PMBV/PVA hydrogel was above 1.0 kPa, the proliferation of encapsulated cells was suppressed and provided uniform cells in G1 phase in cell cycle progression. High G1 phase fraction (>90%) may lead to excellent differentiation efficiency, which results in great insight for stem cell engineering. The PMBV/PVA system is expected to become a key material in cellular engineering for regulating cellular function without undesirable biological events.