Magnesium Implants Release Hydrogen Gas to Speed Bone Healing

Authors
Journal
Bioactive Materials
Year
DOI
10.1016/j.bioactmat.2024.12.020
Study Type
Rat
Outcome
Positive
Peer Reviewed
Yes
Country
China
Health Condition
Bone Fractures
Body System
Skeletal System

TL;DR

Magnesium implants help bones heal by creating a healing-friendly environment and influencing the body's natural pain and growth signals.

Key Finding

Hydrogen gas, magnesium ions, and alkaline pH from degrading magnesium implants each contribute distinct but complementary effects on bone regeneration, working synergistically through nerve-signaling pathways to accelerate fracture healing in rats.

Summary

This study examined how magnesium implants used to fix broken bones work by investigating what happens when the implant breaks down. Researchers found that magnesium implants release three substances—hydrogen gas, magnesium ions, and alkaline compounds—that each help bone healing in different ways. In rats, these three substances worked together to speed up bone regeneration by affecting nerve signals and chemical pathways in newly forming bone.

Practical Takeaway

This animal study provides early evidence that hydrogen gas may play a role in bone healing when released from magnesium implants, though this research is limited to rats and does not directly test hydrogen water. The findings suggest hydrogen gas itself—not just magnesium—may have biological activity in bone repair, but human studies would be needed to determine if hydrogen water has similar effects.

Abstract

Biodegradable magnesium (Mg) implant generally provides temporary fracture fixation and facilitates bone regeneration. However, the exact effects of generated Mg ions (Mg2+), hydrogen gas (H2), and hydroxide ions (OH-) by Mg degradation on enhancing fracture healing are not fully understood. Here we investigate the in vivo degradation of Mg intramedullary nail (Mg-IMN), revealing the generation of these degradation products around the fracture site during early stages. Bulk-RNA seq indicates that H2 and alkaline pH increase periosteal cell proliferation, while Mg2+ may mainly enhance extracellular matrix formation and cell adhesion in the femur ex vivo. In vivo studies further reveal that H2, Mg2+ and alkaline pH individually generate comparable effects to the enhanced bone regeneration in the Mg-IMN group. Mechanistically, the degradation products elevate sensory calcitonin gene-related peptide (CGRP) and simultaneously suppress adrenergic factors in newly formed bone. H2 and Mg2+, instead of alkaline pH, increase CGRP synthesis and inhibit adrenergic receptors. Our findings, for the first time, elucidate that Mg2+, H2, and alkaline pH environment generated by Mg-IMN act distinctly and synergistically mediated by the skeletal interoceptive regulation to accelerate bone regeneration. These findings may advance the understanding on biological functions of Mg-IMN in fracture repair and even other bone disorders.