Functionally Graded Bioactive Composites Based on Poly(vinyl alcohol) Made through Thiol-Ene Click Reaction

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Functionally graded materials (FGMs) mimic bone's hierarchical structure, making them ideal for bone tissue engineering.
• Thiolated poly(vinyl alcohol) (TPVA) offers a versatile polymer matrix for FGMs.
• Nano-hydroxyapatite (nano-HA) is a key component for enhancing bone regeneration properties.

Purpose of the Study:

• To design and develop a novel FGM based on TPVA and nano-HA with graded bioactivity, cell compatibility, and degradability.
• To create a composite material suitable for bone regeneration applications.
• To evaluate the potential of this FGM as a guided bone regeneration (GBR) membrane.

Main Methods:

• Fabrication of TPVA hydrogel via thiol-ene click reaction, avoiding byproducts.
• Incorporation of freshly precipitated and spray-dried nano-HA into TPVA hydrogel in graded concentrations.
• Lyophilization to create porous FGM sheets.
• In vitro characterization including tensile strength, degradation studies in PBS, bioactivity in SBF, and cytocompatibility with human periodontal ligament cells.

Main Results:

• The TPVA-HA FGM exhibited enhanced tensile strength and degradation rates compared to bare TPVA in vitro.
• Bioactivity was confirmed through apatite formation in simulated body fluid (SBF).
• Excellent cytocompatibility was demonstrated with human periodontal ligament cells.

Conclusions:

• The fabricated TPVA-HA composite FGMs possess desirable mechanical, bioactive, and cytocompatible properties.
• These FGMs show significant potential for use as guided bone regeneration (GBR) membranes.
• The study highlights the successful development of a tunable biomaterial for bone regeneration.