A Porous Hydrogel with High Mechanical Strength and Biocompatibility for Bone Tissue Engineering

Abstract

Polyvinyl alcohol (PVA) hydrogels are considered to be ideal materials for tissue engineering due to their high water content, low frictional behavior, and good biocompatibility. However, their limited mechanical properties restrict them from being applied when repairing load-bearing tissue. Inspired by the composition of mussels, we fabricated polyvinyl alcohol/hydroxyapatite/tannic acid (PVA/HA/TA) hydrogels through a facile freeze–thawing method. The resulting composite hydrogels exhibited high moisture content, porous structures, and good mechanical properties. The compressive strength and tensile strength of PVA hydrogels were improved from 0.77 ± 0.11 MPa and 0.08 ± 0.01 MPa to approximately 3.69 ± 0.41 MPa and 0.43 ± 0.01 MPa, respectively, for the PVA/HA/1.5TA hydrogel. The toughness and the compressive elastic modulus of PVA/HA/1.5TA hydrogel also attained 0.86 ± 0.02 MJm−3 and 0.11 ± 0.02 MPa, which was approximately 11 times and 5 times higher than the PVA hydrogel, respectively. The PVA/HA/1.5TA hydrogel also exhibited fatigue resistance abilities. The mechanical properties of the composite hydrogels were improved through the introduction of TA. Furthermore, in vitro PVA/HA/1.5TA hydrogel showed excellent cytocompatibility by promoting cell proliferation in vitro. Scanning electron microscopy analysis indicated that PVA/HA/1.5TA hydrogels provided favorable circumstances for cell adhesion. The aforementioned results also indicate that the composite hydrogels had potential applications in bone tissue engineering, and this study provides a facile method to improve the mechanical properties of PVA hydrogel.

A study on the material properties of novel PEGDA/gelatin hybrid hydrogels polymerized by electron beam irradiation

“…Figure 2B indicates that as the content of gelatin increases, the tensile strength of the hydrogel also increases. The higher strength of hydrogels may be due to their high degree of polymerization ( Xiang et al, 2022 ). Thus, also tensile test results confirms the beneficial effect on the mechanical properties by combining gelatine and PEGDA in a cross linked hydrogel.…”

Carbonic Anhydrase Enhanced UV-Crosslinked PEG-DA/PEO Extruded Hydrogel Flexible Filaments and Durable Grids for CO2 Capture

“…This tensile strength value compares favorably with that of high-strength hydrogels summarized in a recent review [ 41 ]. For example, poly (vinyl alcohol) hydrogel reinforced by hydroxyapatite and tannic acid only had a tensile strength of 0.43 MPa [ 42 ]. A type of advanced high performance hydrogel related to IPNH is called a double network hydrogel (DNH) [ 43 ], which has literature reported tensile strength values falling mostly in the range of 1–10 MPa [ 41 ].…”

Emerging roles of hydrogel in promoting periodontal tissue regeneration and repairing bone defect

“…Due to the relatively simple structure and limited functionality of PVA, reinforcing components and functional materials are often incorporated into PVA hydrogel networks to improve and modify the overall performance of the hydrogel. Xiang et al (2022) prepared a polyvinyl alcohol/hydroxyapatite/tannic acid (PVA/HA/TA) composite hydrogel, which exhibited high water content, porous structure, and good mechanical properties. In vitro cell experiments demonstrated excellent cell compatibility of the PVA/HA/TA composite hydrogel, promoting cell growth and adhesion, making it a promising material for bone tissue engineering.…”