Facile preparation and properties of porous poly(vinyl alcohol)/trehalose/nano-clay hydrogels with high mechanical strength for potential application in bone tissue engineering

Abstract

Among various biomaterials, hydrogels are considered as the most attractive tissue engineering material due to their resemblances to extracellular matrix. However, due to the poor mechanical properties, poly(vinyl alcohol) hydrogels are restricted to be applied in load-bearing tissue repair and regeneration. In this work, we designed a series of porous biocompatible composite hydrogels with tough mechanical properties for bone tissue engineering, consisting of poly(vinyl alcohol), trehalose and nano-clay. These novelty hydrogels were prepared by a facile one-pot method. Compositions, microscopic structures, and mechanical properties of hydrogels were investigated in detail. The maximum compressive strength, compressive modulus, tensile strength, elastic modulus, and toughness of hydrogels attained about 2.71 MPa, 0.163 MPa, 0.741 MPa, 0.084 MPa, and 0.94 MJ/m3, respectively. These as-prepared hydrogels exhibited the excellent mechanical properties, which were ascribed to the hydrogen bond interactions between molecules and nano-enhancement effect of the nano-clay. Meanwhile, as-prepared hydrogels also exhibited a three-dimensional and interconnected porous microstructure, which facilitated the transport of nutrients to promote cells growth. In addition, the mechanical properties and microscopic structures of hydrogels could be controlled by adjusting the concentrations of trehalose and nano-clay. In vitro cell experiments demonstrated that the hydrogels had good biocompatibility. And hydrogels possessed the excellent ability to induce MC3T3-E1 cells osteogenesis to accelerate bone defects repair. Above illustrated results demonstrated that the potential applications of the hydrogels used as bone tissue engineering materials. Therefore, we anticipated this kind of poly(vinyl alcohol)-based composite hydrogel could develop a new strategy for bone tissue repair.