Cytocompatible and reverse-transformable polymeric hydrogel matrices

Cell engineering is an important new medical technology in regenerative medicine. To regulate cellular functions some polymeric materials have been considered to conjugate with cells. In particularly, hydrogels are good candidate as the materials. Temporal and spatial encapsulations of cells by smart hydrogels are gaining attention as a novel way of handling cells in 3D conditions. In situ gelation of polymers by temperature change and spontaneously gelation by two polymeric materials have been investigated for encapsulation of cells. Cytocompatible and reversible transfer of phospholipid polymer hydrogels were examined for the control of cell functions. Hydrogels were prepared by mixing aqueous solutions of poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl 310methacrylate-co-p-vinylphenylboronic acid) (PMBV), and poly(vinyl alcohol) (PVA). Both human cancer cells (HeLa cells) and murine mesenchymal stem cells (C3H10T1/2 cells) showed suppression of proliferation when they were encapsulated in the PMBV/PVA hydrogels with a storage modulus of 1.1 kPa. The encapsulated cells were unified to the G1 phase in the cell proliferation cycle after one day of encapsulation. In addition, the differentiation of C3H10T1/2 cells into osteogenic cells mediated by bone morphogenetic protein-2 (BMP-2) was evaluated by the polymerase chain reaction method after induction of the BMP-2 signal for three days. The cells encapsulated in the PMBV/PVA hydrogels showed over fourfold increase in early-stage osteoblastic gene expression with well-defined quality. These results will contribute substantially to the field of regenerative medicine.