Porous structures help boost integration of host tissue with implants, study finds

Jan 30, 2008

Results published today in FASEB (the journal of the Federation of American Societies for Experimental Biology) by researchers at Columbia University, including Jeremy Mao of the Columbia College of Dental Medicine, demonstrate a novel way of using porous structures as a drug-delivery vehicle that can help boost the integration of host tissue with surgically implanted titanium.

Instead of being acted upon by the body as an impenetrable foreign object, the synthetic bone replacement – currently being tested in rabbits – features a porous material that allows for the delivery of “microencapsulated bioactive cues” that speed up the growth of host tissue at the site and allow for the growth of new bone.

A critical finding is that the drug dose needed for host tissue integration by this controlled-release approach is about 1/10 of that by the traditional technique of simple adsorption of the growth factor.

The approach could bring to orthopedics and dentistry a treatment that has wrought much interest and success in the field of cardiology with the development of drug-eluting stents, which take what is ordinarily an inert tube, and infuse it with drugs to make the placement of what is essentially a man-made, foreign object more compatible with the patient’s body, and at the same time, actively promoting healing of injured tissue.

After just four weeks, the porous implants that Mao and his team are using showed a 96 percent increase in bone-to-implant contact and a 50 percent increase in the growth of new bone over placebos.

How were such results achieved?

Since stem cells play a vital role in the growth of new bone, Mao and his team have focused on impregnating the titanium implants with a factor that “homes” the bodies’ own regenerating cells to the potential growth site to create and build on a platform for new bone.

The new approach may in the future obviate the need to harvest bone from a non-injured site in the body for grafting into the site of injury, as commonly performed now. This strategy, although often effective, creates additional wounds. The work of Mao and his team suggests that it should be possible to harnesses the body’s natural tissue regeneration capacity to recruit the right cells to the site where new bone tissue is needed. Implants that naturally attract the mesenchymal stem cells that can readily differentiate into bone, fat, cartilage and other types of cells could be the way of the future, Mao says. “In comparison with donor site morbidity and pain in association with autologous tissue grafting, synthetic materials have the advantage of ready and endless supply without any sacrifice of donor tissue,” he says.

The approach also overcomes a practical obstacle confronting many orthopedic surgeons.

“This is a hybrid approach releasing biological cues from existing orthopedic and dental implants to recruit the body’s own stem cells. It’s unrealistic, at least from what we know now, to build a cell culture room next to every operating room,” Mao added. “Using these types of porous implants doesn’t require physicians to deliver stems cells so much as it allows the patient’s body to send its own cells to the right place.”

Source: Columbia University Medical Center

Explore further: Honey bees sting Texas man about 1,000 times

add to favorites email to friend print save as pdf

Related Stories

Advancing medicine, layer by layer

Jul 02, 2014

Personalized cancer treatments and better bone implants could grow from techniques demonstrated by graduate students Stephen W. Morton and Nisarg J. Shah, who are both working in chemical engineering professor ...

Muscle-powered bio-bots walk on command (w/ Video)

Jun 30, 2014

(Phys.org) —A new generation of miniature biological robots is flexing its muscle. Engineers at the University of Illinois at Urbana-Champaign demonstrated a class of walking "bio-bots" powered by muscle ...

Better tissue healing with disappearing hydrogels

Jun 06, 2014

When stem cells are used to regenerate bone tissue, many wind up migrating away from the repair site, which disrupts the healing process. But a technique employed by a University of Rochester research team ...

Recommended for you

Study indicates large raptors in Africa used for bushmeat

2 hours ago

Bushmeat, the use of native animal species for food or commercial food sale, has been heavily documented to be a significant factor in the decline of many species of primates and other mammals. However, a new study indicates ...

The microbes make the sake brewery

3 hours ago

A sake brewery has its own microbial terroir, meaning the microbial populations found on surfaces in the facility resemble those found in the product, creating the final flavor according to research published ahead of print ...

Fighting bacteria—with viruses

4 hours ago

Research published today in PLOS Pathogens reveals how viruses called bacteriophages destroy the bacterium Clostridium difficile (C. diff), which is becoming a serious problem in hospitals and healthcare institutes, due to its re ...

User comments : 0