Body & Mind

Piezoelectric "bone bandage" heals cracked bones faster

Piezoelectric "bone bandage" heals cracked bones faster
A novel "bone bandage" was able to regenerate damaged bone in mice
A novel "bone bandage" was able to regenerate damaged bone in mice
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A novel "bone bandage" was able to regenerate damaged bone in mice
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A novel "bone bandage" was able to regenerate damaged bone in mice
(d) Micro CT images showing bone regeneration in mice skulls using different scaffolds and (e) bone volume and area at 2, 4, and 6 weeks after scaffold implantation
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(d) Micro CT images showing bone regeneration in mice skulls using different scaffolds and (e) bone volume and area at 2, 4, and 6 weeks after scaffold implantation

Researchers have successfully regenerated damaged skull bones in mice by creating a freestanding, biomimetic scaffold that combines a piezoelectric framework and the growth-promoting properties of a naturally occurring mineral. The novel “bone bandage” has wide-ranging potential applications for bone regeneration and regenerative medicine generally.

Piezoelectric materials generate an electric charge in response to applied mechanical stress. Bone is a piezoelectric material. Because it possesses an electrical microenvironment, electrical signals play an important role in the bone repair process, which can effectively promote bone regeneration. However, bone regeneration is a complex process that relies on mechanical, electrical, and biological components.

Current strategies for bone regeneration, such as grafts or scaffolds that release growth factors, have limitations, such as complications at the donor site, limited availability, and high cost. Now, researchers from the Korea Advanced Institute of Science and Technology (KAIST) have developed a pioneering approach to bone regeneration that combines piezoelectricity and a mineral that occurs naturally in bone.

Hydroxyapatite (HAp), a mineral in bones and teeth, plays a role in bone’s structural strength and regeneration. It’s commonly added to toothpaste to remineralize tooth enamel and fortify teeth. Studies have found that HAp enhances osteogenesis (bone formation) and provides a scaffold for new bone growth. It also has piezoelectric properties and a rough surface, making it an ideal candidate for creating scaffolds on which to grow bone.

So, the researchers fabricated a freestanding biomimetic scaffold, integrating HAp within the piezoelectric framework of polyvinylidene fluoride-co-trifluoro ethylene (P(VDF-TrFE)), a polymer film. The independent scaffold, which generates electrical signals when pressure is applied, sets this approach apart from previous research combining HAp and P(VDF-TrFE), which was limited to coatings on metallic prosthetics. The researchers’ novel approach, they say, provides a versatile platform for bone regeneration beyond surface-bound applications.

Comparing scaffolds with and without HAp in vitro showed that cell attachment on HAp scaffolds was 10% to 15% higher. After five days of cell culture, cell proliferation was 20% to 30% higher, and there were approximately 30% to 40% higher levels of osteogenesis on the HAp scaffolds. The findings suggest HAp maximizes the piezoelectric properties of the scaffold and creates an environment similar to the body’s extracellular matrix, the non-cellular component of all tissues that provides essential physical structure and the important cues required for tissue regeneration.

(d) Micro CT images showing bone regeneration in mice skulls using different scaffolds and (e) bone volume and area at 2, 4, and 6 weeks after scaffold implantation
(d) Micro CT images showing bone regeneration in mice skulls using different scaffolds and (e) bone volume and area at 2, 4, and 6 weeks after scaffold implantation

The researchers then tested their HAp/P(VDF-TrFE) scaffolds on mice, placing them over defects in the animals’ skull bones (calvaria). The scaffolds were maintained for six weeks without deformation. All mice survived; no adverse events were observed, including no infection or inflammatory response. After two, four, and six weeks of implantation, bone regeneration was significantly enhanced in the mice with HAp scaffolds fitted compared to no bone formation in the control groups.

“We have developed a HAp-based piezoelectric composite material that can act like a ‘bone bandage’ through its ability to accelerate bone regeneration,” said Seungbum Hong, one of the study’s corresponding authors. “This research not only suggests a new direction for designing biomaterials but is also significant in having explored the effects of piezoelectricity and surface properties on bone regeneration.”

The study was published in the journal ACS Applied Materials & Interfaces.

Source: KAIST

2 comments
2 comments
vince
I wonder if pizeoelectric casts could heal the bone damages from the dreaded disease called Perthes disease. That disease keeps bones from hardening and they flow like hard putty and deform. Which is dreadful when it attacks ball joints as the round balls can squish and flatten and make it impossible for a person to walk or move their arms depending on where the disease attacks the bodies bones. Back in the 50's it was a dreadful affliction and the only cure was to keep weight off the ball joints until the body cured itself and the bones hardened. I know as I spent 3.5 years in a full body cast from tip of my toes to upper chest from ages 6 to 9.5 years old. Both legs were wrapped and a crossbar inserted by knees to separate the legs about 30 degrees. Needless to say spending almost your entire childhood in a full body cast is really a hard life. Its no fun having to have the casts cut off every 3 months as you age to allow for growth and itch like heck and no clothes hangar scratching tool could reach every itch. So of pizeoelectric could help shorten the healing time that would.be wonderful.
jimbo92107
Wow, this finding suggests not only does the dual piezo-Hap scaffolding work, but that further refinements of this tech could result in even better bone coverage over time. Why was there still a gap? Could a different formulation work better, or a scaffold with a bit of actual bone fiber to bridge the gap? Would the scaffold work better if tiny fragments of bone were "seeded" in the scaffold? Fun stuff!