PolyU scheme helps in fractures recoveryLocal | Ruby Cheung 15 Aug 2018
Researchers have designed a bone scaffold with shape memory foam that can be implanted into bone defects and help in the recovery of fractures.
As fractures become a worldwide health concern, especially in aging societies, improving bone graft procedures and inducing bone regeneration effectively while lowering medical expenses has become a challenge for scientists.
Hong Kong has an average of over 9,500 cases of osteoporosis-induced hip fractures, and the figure is expected to triple by 2050.
However, the bone scaffold, developed by researchers at the Hong Kong Polytechnic University, offers a promising breakthrough since researchers designed and fabricated the scaffold with shape memory foam and self-fitting characteristics for minimally invasive implants.
By combining shape memory foam and hydroxyapatite - the principal mineral component of bone tissue - the university's innovation can be safely and conveniently implanted into bone defects and induce bone regeneration, thus enhancing recovery of fractures of other bone-related injuries.
Despite the regenerative capacity of bones, patients need to undergo bone grafts to orchestrate bone regeneration should they be diagnosed with bone tumor resections or severe fractures.
The novel scaffold is made of shape memory polyurethane foam and HA nano-particles, which characterizes its remarkable self-fitting effect.
With the shape memory material, the scaffold can be compacted at zero degrees Celsius and recover its original shape at 40 degrees, enabling it to fill the irregular bone defects perfectly.
The transitional temperatures are in close range to the human body's physiological temperatures, which also enhances the feasibility of using the scaffold in minimally invasive surgery.
A rabbit femoral defect study proved that it can be safely and conveniently implanted into bone defects and induce bone regeneration.
In the study, 18 rabbits with a femoral bone defect in each knee, comprising a total of 36 lesions, were divided into an experimental group and a control group.
The bone defects of the rabbits in the experimental group were implanted with the self-fitting scaffolds, while the bone defects in the control group were left unfilled.
Twelve weeks after the surgery, the experimental group displayed faster bone tissue growth in volume, while 46 percent of total defects had been repaired. In contrast, only 24 percent of total defects among the rabbits in the control group had been repaired.
Hu Jianlian, a professor at the university's Institute of Textiles and Clothing, said the self-fitting scaffold has been proven to induce the formation of osteoblasts and blood vessels, which are both responsible for the synthesis of bone tissue.
"The results show that our scaffold has overcome the disadvantages of traditional polymer scaffolds, and has great potential for bone regeneration," Hu said.
Hu added that the shape memory scaffold developed by Hong Kong Polytechnic University has the advantage of being minimally invasive with full biocompatibility. Its ability to self adapt also makes it an optimal solution for bone remodeling.