Exploring Science Communication Through Popular Science

Sticks and stones may break your bones, but this new bone cement can fix itAs one ages, you can expect to experience a decline in health. Your bones get weaker, you fall sick more easily and are generally more susceptible to ailments. We all know that illnesses can be treated with medication but what about our weakened bones? A group of Chinese researchers have recently fabricated a new type of bone cement that is even more refined than the current commercially available calcium phosphate cement (CPC).Bone cement is a self-curing material that can fill up holes and aid in the mechanical repair of bones. It can be found as a paste and can also be easily injected in. It is usually used for irregular bone defects and unstable fractures that are characteristic of conditions such as osteoporosis. As Singapore’s population is aging rapidly, this common condition among the elderly is likely to become an even more important health problem the country has to tackle and this new discovery may just provide the assistance needed.

Currently, the CPC being used is poorly resorbable and not highly adhesive to the bones. Resorption is the absorption of the material into the circulation of cells and tissue. It is important for CPC to be resorbable as this ensures that new bone is reforming and substituting the implant itself. A revolutionary form of magnesium potassium phosphate cement (MKPC) has been fabricated and directly compared to CPC in an experiment conducted by researchers in China West Normal University.

In the experiment, MKPC and control sample CPC were implanted into separate legs of the same rabbit in 24 different rabbits. Critical defects were made in the rounded end of the thighbone in the kneecap by a standardised surgical procedure. These holes in the bones were then filled in with MKPC or CPC. All rabbits were kept in the same living conditions and were fed the same diet and medication. Six rabbits (12 limbs) each were studied at different time points of the experiment for comparison. These limbs were obtained on the day of the surgery, 4, 12 and 26-weeks after surgery.A plain radiograph (image produced on a plate or film using radiation like X-rays) was used to evaluate the status of bone regeneration between the two bone cements. The bone defect regions were also cut out and observed under different types of microscopes to observe if the implanted bone cements were degrading, bone formation and for the metabolism of the real bone surrounding the implants.

To measure the resorption of the implants, sections crossing the middle of the implants were analysed by measuring the shape and form of the tissue. These measurements were then calculated to see the percentages that are made up of bone and the bone cement material. From the measurements, it was also seen that bone was formed on the CPC surface at week 3, but resorption of CPC rarely occurred in 4 and 12 weeks. However, resorption of MKPC continued and paralleled the new bone formation even after 26 weeks. At 26 weeks after implantation of MKPC had a higher percentage of newly formed bone and 37% of MKPC was resorbed. However, for CPC 80% of the material remained in the defects.

The compressive strength of MKPC and CPC was measured at room temperature prior to the experiment using a biomechanical testing machine. It is found that the compressive strength of CPC is lower than that of MKPC. Due to that, CPC disintegrates into small particles in the body.

From the experiment, it is concluded that MKPC has a higher resistance to compression, higher resorption rate and enhanced bone regeneration compared to CPC. No inflammatory reactions or death of cells as a result of the implantation were observed as well. From here, we see that MKPC has a high potential in being used for clinical applications. With such promising results, we can hope that with further research and development, that this novel type of MKPC will be used commercially as a bone void filler and bio-adhesive in the near future.