Featured Research

from universities, journals, and other organizations

New coating may help joint replacements bond better with bone

Date:
July 29, 2013
Source:
Ohio State University
Summary:
Researchers have found that bone cells grow and reproduce faster on a textured surface than they do on a smooth one —- and they grow best when they can cling to a microscopic shag carpet made of tiny metal oxide wires.

Cells show signs of healthy growth in this transmission electron microscope image, taken 15 hours after the cells were placed on a titanium surface coated with a carpet of tiny nanowires. In the inset (upper left), filaments can be seen reaching out from cells to the surface, which indicates a strong connection.
Credit: Image courtesy of Sheikh Akbar, Ohio State University

Broken bones and joint replacements may someday heal faster, thanks to an unusual coating for medical implants under development at The Ohio State University.

Related Articles


Researchers here have found that bone cells grow and reproduce faster on a textured surface than they do on a smooth one -- and they grow best when they can cling to a microscopic shag carpet made of tiny metal oxide wires.

In tests, the wires boosted cell growth by nearly 80 percent compared to other surfaces, which suggests that the coating would help healthy bone form a strong bond with an implant faster.

The engineers developed an affordable technique for creating the wires, which they describe in a paper in the July 2013 issue of the journal Ceramics International.

"What's really exciting about this technique is that we don't have to carve the nanowires from a solid piece of metal or alloy. We can grow them from scratch, by exploiting the physics and chemistry of the materials," said Sheikh Akbar, professor of materials science and engineering at Ohio State. "That's why we call our process 'nanostructures by material design.'"

Akbar's team (co-advised by his colleague, Suliman Dregia, associate professor of materials science and engineering) was able to grow the wires by tailoring the mix of materials and gases inside a furnace. At temperatures around 1,300 degrees Fahrenheit, fine filaments of titanium dioxide rose from a smooth titanium surface. Each was tens of thousands of times smaller than a human hair.

But then something unusual happened that the engineers couldn't explain. Each wire grew a protective coating of aluminum oxide around itself -- like a layer of bark around a tree trunk. The growth of the coating might make sense, if the material in the furnace were a titanium alloy that contained aluminum. But in this case, the researchers were working with pure titanium, so it's not clear how the wires grew an aluminum coating.

"It's strange that we don't completely understand why this process works the way it does. We're going to have to do some fancy microscopy to figure it out, but we do know that the wires only form under just the right conditions," Akbar said.

In tests, the researchers grew bone cancer cells on three different surfaces: smooth titanium, smooth titanium dioxide, and the nanowire carpet. (They chose the cancer cells because the cells are particularly hardy, and also reproduce the same way healthy bone cells do.)

The biggest difference in cell growth occurred within the first 15 hours of testing, when researchers measured a 20 percent higher concentration of the bone-growth enzyme alkaline phosphatase being produced by the cells growing on the nanowires. By the end of the study, there were around 90,000 cells per square centimeter on the nanowire surface -- 80 percent more than the 50,000 cells per square centimeter on each of the other two surfaces.

Study co-author Derek Hansford, associate professor of biomedical engineering and materials science and engineering, said that the coating could aid people who have hip and knee replacements, dental implants, or broken bones that require screws and plates to repair them.

"Our hope is that this surface treatment will become a simple-to-implement modification to titanium implants to help them form a stronger interface with surrounding bone tissue. A stronger interface means that implants and bones will be better able to share mechanical loads, and we can better preserve healthy bone and soft tissue around the implant site," Hansford said.

Akbar believes that the price is right for commercial development. $100 worth of metal foil is enough to make hundreds of samples.

The method to grow the wires is also exceedingly simple. Beyond setting the right mix of materials and gases, it involves little other than pressing a button to turn on the laboratory furnace.

"Seriously, if you spent the day in my lab, you could learn how to do it yourself," Akbar said.

He and his team are now exploring other material and gas combinations to make different nano-sized shapes for cell growth and chemical sensing.

This work was partially funded by the National Science Foundation.


Story Source:

The above story is based on materials provided by Ohio State University. The original article was written by Pam Frost Gorder. Note: Materials may be edited for content and length.


Journal Reference:

  1. B. Dinan, D. Gallego-Perez, H. Lee, D. Hansford, S.A. Akbar. Thermally grown TiO2 nanowires to improve cell growth and proliferation on titanium based materials. Ceramics International, 2013; 39 (5): 5949 DOI: 10.1016/j.ceramint.2012.12.004

Cite This Page:

Ohio State University. "New coating may help joint replacements bond better with bone." ScienceDaily. ScienceDaily, 29 July 2013. <www.sciencedaily.com/releases/2013/07/130729132924.htm>.
Ohio State University. (2013, July 29). New coating may help joint replacements bond better with bone. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2013/07/130729132924.htm
Ohio State University. "New coating may help joint replacements bond better with bone." ScienceDaily. www.sciencedaily.com/releases/2013/07/130729132924.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Kids Die While Under Protective Services

Kids Die While Under Protective Services

AP (Dec. 18, 2014) As part of a six-month investigation of child maltreatment deaths, the AP found that hundreds of deaths from horrific abuse and neglect could have been prevented. AP's Haven Daley reports. (Dec. 18) Video provided by AP
Powered by NewsLook.com
Dads-To-Be Also Experience Hormone Changes During Pregnancy

Dads-To-Be Also Experience Hormone Changes During Pregnancy

Newsy (Dec. 18, 2014) A study from University of Michigan researchers found that expectant fathers see a decrease in testosterone as the baby's birth draws near. Video provided by Newsy
Powered by NewsLook.com
Prenatal Exposure To Pollution Might Increase Autism Risk

Prenatal Exposure To Pollution Might Increase Autism Risk

Newsy (Dec. 18, 2014) Harvard researchers found children whose mothers were exposed to high pollution levels in the third trimester were twice as likely to develop autism. Video provided by Newsy
Powered by NewsLook.com
UN: Up to One Million Facing Hunger in Ebola-Hit Countries

UN: Up to One Million Facing Hunger in Ebola-Hit Countries

AFP (Dec. 17, 2014) Border closures, quarantines and crop losses in West African nations battling the Ebola virus could lead to as many as one million people going hungry, UN food agencies said on Wednesday. Duration: 00:52 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins