Category: Skeletal System

Prunes Also Protect Bone Health in Men

Photo by Nino Liverani on Unsplash

New research published in the Journal of Food and Medicine reports that daily prunes consumption protects bone health in men over 50. This study is the first of its kind to examine the beneficial prune effect on bones in men. 

Some 2 million men are estimated to be battling osteoporosis and another 16.1 million men have osteopenia, or low bone mass. Despite these numbers, bone disease in men is often overlooked.

“We’ve already seen significant evidence that prunes have a positive effect on bone health in women, so it’s particularly exciting to find that prunes can also play a beneficial role in men’s bone health. We look forward to continuing to study the ‘prune effect’ on bone and other health outcomes in men,” said lead researcher Professor Shirin Hooshmand at San Diego State University.

In this study, 57 healthy men aged 50-79 years old were randomised to either consume 100 grams of prunes every day or no prunes for twelve months. After a year, the prune consumers showed significant decreases in biomarkers of bone breakdown, while no changes were observed in the control group. The study authors also reported the men who ate prunes showed improvements in bone geometry indicating greater bone strength.

Historically, research has focused on osteoporosis and bone health in women, already indicating a favorable bone response to prunes specifically among postmenopausal women. Several studies have suggested that eating 50 to 100 grams of prunes everyday could lead to increased bone mass and decreased bone breakdown. Moreover, a recent case study earlier this year reported that total bone mineral density increased in a postmenopausal woman with osteopenia after she consumed 50 grams of prunes daily for 16 months.

“Bone health is not just a concern for women. Men need to think about how to protect their bones as well,” said Leslie Bonci, MPH, RDN and consultant with the California Prune Board. “Prunes are a shelf-stable and nutrient-packed food that provide a preventive, proactive, palatable option for men to optimize their bone health.”

While San Diego State University’s newest research is an exciting addition to existing prune-focused literature, more work on the effect of prunes on human bone health is currently underway. An upcoming study from Pennsylvania State University examines how consuming different amounts of prunes affects health outcomes in postmenopausal women over a one-year period. The study not only explores the impact of prunes on bone health, but it will also look at the prune-effect on inflammation and gut health.

Source: PR Newswire

How Osteocytes Form Their Networks of Dendrites

Phot by Nino Liverani on Unsplash

Embedded within bone tissue are osteocytes, and the tree-like communication cells known as dendrites. Loss of dendrites to ageing contributes to bone fragility and osteoporosis. 

A study published in Nature Communications has revealed how osteocytes form dendrites – a discovery that might yield strategies to maintain these projections and therefore help maintain people’s bone health throughout their lives.

In their study, the researchers found that deletion of Sp7, a gene linked to both rare and common skeletal diseases, in osteocytes causes severe defects in osteocyte dendrites. This gene codes for a protein called a transcription factor, which controls the expression of other genes. The team found that the Sp7 transcription factor targets a gene called osteocrin, which promotes osteocyte dendrite formation. In mice, activating the osteocrin gene made up for the absence of Sp7 and reversed defects in osteocyte dendrites.

“In this work, we demonstrate key roles for the transcription factor Sp7 and its target osteocrin in orchestrating a gene regulatory network needed to promote healthy connections between bone cells,” said senior author Marc Wein, MD, PhD, an investigator in the endocrine unit at MGH and an assistant professor of medicine at Harvard Medical School. “Understanding how osteocytes maintain this network of connections opens up exciting possibilities for new ways to treat osteoporosis and other diseases where bones are prone to fracture.”

Source: Massachusetts General Hospital

Atmospheric Plasma Device Boosts Bone Regeneration

Photo by Zoltan Tasi on Unsplash

Scientists in Japan have developed a plasma device that promotes bone regeneration in fractures.

Unlike blood plasma, plasma here refers to the fourth state of matter, effectively a highly ionised gas, which has been long investigated as an effective surgical scalpel which cauterises tissue as it cuts. Other recent applications of plasma technology include surface sterilisation.

Now, a new type of plasma device, termed non-thermal atmospheric pressure plasma (NTAPP), was successfully tested in healing of bone fractures in animal bone defect models. It is cooler than most plasmas that are typically used. In a study published in PLOS ONE, researchers from Osaka City University detailed their findings using the technology in this world-first application.

Acceleration of cell growth
“NTAPP is considered a new therapeutic method,” said first author Akiyoshi Shimatani, “as it has been shown to accelerate cell growth when applied at low enough levels.” He explained that in an ambient atmosphere it can generate highly reactive oxygen and nitrogen species (RONS) which can be directly exposed to tissues.

Indirect treatments have shown the potential advantages of plasma in supporting the creation of stem cells that cause reactive oxygen species and in inducing osteogenic differentiation and bone formation, however, as the team points out there is no report on directly using NTAPP for bone fracture therapy. “Direct exposure of NTAPP is a key part of this study” states Jun-Seok Oh, professor at the OCU Graduate School of Engineering and advisor to the study, “It required a device specifically designed to generate and deliver RONS to areas of the bone defect ‘effectively’.”

The research group developed a pencil-like plasma device that can effectively generate and deliver RONS to an animal model with a well-established critical bone defect, allowing the team to search for the optimal exposure conditions. Comparing groups that were treated with NTAPP for 5, 10, and 15 minutes to control groups with no plasma administered, micro-CT images at eight weeks showed the 10-minute treatment time as the most successful bone regeneration with 1.51 times larger bone volume than the control group.

Since micro-CT images could not determine whether a bone defect has been filled with new bone, tissue or both, the team also ran a histological analysis and confirmed bone defects in the groups treated with plasma were in fact filled with new bone, and had no tissue or gaps like the control groups.

Precision therapy
The biological effect of plasma, like other therapies, depends on the treatment dose delivered into the targets. Although future research will be needed to clarify why the study saw the most bone regeneration during the 10-minute treatment period, surface wettability is understood to promote greater cell spreading and adhesion to biomaterials and implants. Hiroaki Nakamura, professor at the Graduate School of Medicine explained: “We wondered if something similar was occurring where we saw a strong generation of new bone. And we found that compared to the control group, bone surface of the plasma-treated group as statistically and significantly more hydrophilic.”

The research team hopes the plasma device they developed can be applied for surgical use.

Source: Osaka City University

Osteoclast Signalling Could Yield Osteoporosis Treatments

Photo by cottonbro from Pexels

A new discovery about a signalling function in osteoclasts suggests a potential treatment target for osteoporosis and for bone loss from rheumatoid arthritis.

The findings from University of Virginia School of Medicine researchers and their collaborators help us understand why osteoclasts begin to break down more bone than the body replaces.

“Bone degradation and subsequent repair are fine-tuned through complex interactions between the cells that degrade the bone – osteoclasts – and those that produce new bone matrix. Simple elimination of osteoclasts is, therefore, not always the best approach to treat pathologic bone loss. Instead, we found a ‘signalling node’ in osteoclasts that regulates their function in degrading the bone, but doesn’t reduce osteoclast numbers,” said researcher Sanja Arandjelovic of UVA’s Department of Medicine and UVA’s Carter Immunology Center.

With further research, it may be possible for scientists to one day be able to develop drugs that target the signalling node to prevent or treat bone loss. This discovery also helps explain why some previous attempts to develop osteoporosis treatments produced disappointing results.
Researcher Kodi Ravichandran, chair of UVA’s Department of Microbiology, Immunology and Cancer Biology and director of UVA’s Center for Cell Clearance, noted the potential of the findings to inform efforts to develop better treatments for osteoporosis: “In this study,” he said, “we identified previously unappreciated factors that contribute to osteoclast function that are truly exciting and open up new avenues to pursue.”

The researchers have found an important contributor, a cellular protein called ELMO1, which promotes the activity of the bone-removing osteoclasts. Osteoclasts are critical for bone health, as they normally remove just enough to stimulate new bone growth. The problem arises when the osteoclasts become too aggressive and remove more bone than the body makes, resulting in bone mass loss.

This excessive bone degradation is likely influenced by genetic factors, the researchers say. They note that many of the genes and proteins linked to ELMO1 have been previously associated with bone disorders and osteoclast function.

Encouragingly, the researchers were able to prevent bone loss in lab mice by blocking ELMO1, including in two different models of rheumatoid arthritis. That suggests clinicians may be able to target the protein in people as a way to treat or prevent bone loss caused by osteoporosis and rheumatoid arthritis, the researchers say.

They note that prior efforts to treat osteoporosis by targeting osteoclasts have had only mixed success, and they offer a potential explanation for why: Osteoclasts not only remove bone, but play a role in calling in other cells to do bone replacement. As such, targeting ELMO1 may offer a better option than simply waging war on the osteoclasts.

“We used a peptide to target ELMO1 activity and were able to inhibit degradation of the bone matrix in cultured osteoclasts without affecting their numbers,” Ravichandran said. “We hope that these new osteoclast regulators identified in our study can be developed into future treatments for conditions of excessive bone loss such as osteoporosis and arthritis.”

Source: University of Virginia

A ‘Fountain of Youth’ for Bone Marrow Stem Cells

Source: National Cancer Institute on Unsplash

Scientists have shown that reduced bone marrow stem cell function with ageing is due to changes in their epigenome, and they were able to reverse these changes in isolated stem cells by adding acetate. This ‘fountain of youth’ for the epigenome could become important for the treatment of diseases such as osteoporosis.

One responsible mechanism for age-related osteoporosis and fracture risk involves the impaired function of the bone-marrow stem cells, which are required for the maintenance of bone integrity. 

For a long time, researchers have looked at epigenetics as a cause of ageing. Epigenetics looks at changes that affect the activity of genes. One of these is changes in proteins called histones, which package and thus control access to DNA. In this study, the researchers investigated the epigenome of mesenchymal stem cells, which are found in bone marrow and can give rise to different types of cells such as cartilage, bone and fat cells.

“We wanted to know why these stem cells produce less material for the development and maintenance of bones as we age, causing more and more fat to accumulate in the bone marrow. To do this, we compared the epigenome of stem cells from young and old mice,” explained Andromachi Pouikli, first author of the study. “We could see that the epigenome changes significantly with age. Genes that are important for bone production are particularly affected.”

The researchers then sought to find out if it was possible to rejuvenate the epigenome of stem cells. To do this, they treated isolated stem cells from mouse bone marrow with a nutrient solution which contained sodium acetate. The cell converts the acetate into a building block that enzymes can attach to histones to increase access to genes, thereby boosting their activity. “This treatment impressively caused the epigenome to rejuvenate, improving stem cell activity and leading to higher production of bone cells,” Pouikli said.

To see if this change could also be responsible for increased fracture risk and osteoporosis with age, the researchers studied human mesenchymal stem cells from hip surgery patients. In elderly patients with osteoporosis, the same epigenetic changes seen with mice were also seen in these human cells.

“Sodium acetate is also available as a food additive, however, it is not advisable to use it in this form against osteoporosis, as our observed effect is very specific to certain cells,” cautioned study leader Peter Tessarz. “However, there are already first experiences with stem cell therapies for osteoporosis. Such a treatment with acetate could also work in such a case. However, we still need to investigate in more detail the effects on the whole organism in order to exclude possible risks and side effects.”

The results were published in the journal Nature Aging.

Source: Max Planck Society

Insights into Stiffness Prognosis of Knee Replacements

Phot by Nino Liverani on Unsplash

A new study could help physicians better manage patients who experience debilitating stiffness after they undergo knee replacement surgery.

Researchers at Hospital for Special Surgery (HSS) in New York City presented their findings at the American Academy of Orthopaedic Surgeons (AAOS) 2021 annual meeting

Stiffness after knee replacement surgery, or total knee arthroplasty (TKA), is a rare but frustrating complication, affecting between 1% and 7% of patients who receive the artificial joints. “Why some people and not others experience limited range of motion after TKA is unknown,” said Ioannis Gkiatas, MD, PhD, an orthopedic surgeon at the University of Ioannina, in Greece, and the first author of the new study.

“The goal of the study was to see if we can help physicians predict how patients will do following the revision surgery, using information gathered before and after the procedure, to shape their postoperative treatment plans,” said Dr. Gkiatas. The work was conducted under the supervision of Peter K. Sculco, MD, hip and knee surgeon at HSS, who is leading a large, ongoing study of patient outcomes after revision TKA for reduced range of motion after index TKA.

The researchers followed 19 men and women who underwent revision TKA at HSS to try to improve stiffness in patients with prior TKA. Patients underwent range of motion testing before the procedure and at six weeks, six months and one year after the operation.

The range of motion of healthy knees ranges from full extension (0 degrees) through the sitting position (90 degrees) to kneeling (approximately 140 degrees). All patients gained an average of 28 degrees of motion after the revision surgery. The benefit mostly appeared in the first six weeks after the operation, then gradually tapered off over time.

Patients with the least restricted mobility had the greatest gains from the revision surgery. Patients who could able to bend their affected knee more than 82 degrees before TKA revision had an 80 percent chance of maintaining that level of mobility, or gaining flexibility in the joint, after the operation and throughout the follow-up period.

However, two-thirds of patients whose range of motion was less than 64 degrees prior to surgery experienced regression in that mobility during the study, never attaining the 82-degree threshold.

“Although 82 degrees doesn’t seem much more than 64 degrees, for the patient it’s a significant difference. With 82 degrees you can perform the basic activities of everyday life,” Dr Gkiatas said. “With these new data, if at six weeks a patient reaches 82 degrees of motion in their knee, we can say they have an 80 percent chance of at least maintaining this range of motion one year after surgery.” 

The study results provide surgeons with the information needed to educate patients with stiff TKA on expected range of motion outcomes after revision surgery: Less than 60 degrees is a poor prognostic finding. Additionally, when patients return for their six-week appointment after revision TKA, and have less than 82 degrees of motion, additional pharmacologic or manual knee manipulation treatments should be done since this patient is at a high risk for range of motion regression and inferior clinical outcome at one-year post-revision.

Source: EurekaAlert!

Plant-derived Substance Shows Osteoprotective Properties

Researchers have found that a substance derived from Saussurea controversa, a member of the thistle family, may have significant potential in recovering lost bone mass.

Metabolic bone diseases such as osteoporosis are called the silent epidemic of the 21st century. A person may only become aware of their condition by sustaining a hip or spine fracture.

According to statistics, every third woman and every fifth man after 50 have osteoporosis. Thus, it is promising to search for and obtain substances and materials for implants that have osteoinductive properties and are capable of initiating the processes of transformation of stem cells into bone.

Certain trace elements, such as calcium and magnesium, influence the processes of bone regeneration and the maintenance of their normal structure. Organic molecules that can bind to them provide an improvement in the selectivity of their therapeutic action – the resulting complexes play a significant role in bone formation and development. From this point of view, salts of chelidonic acid have great potential, for example, from the Saussurea controversa known since ancient times for its healing properties.

Researchers from the Immanuel Kant Baltic Federal University, Siberian State Medical University, and Tomsk Polytechnic University had previously discovered that calcium chelidonate is a promising drug for bone volume restoration. 

In their latest work, they obtained this substance in a semisynthetic way: extracts from Saussurea controversa were the source of the chelidonic acid, to which an alkali solution and calcium chloride were added.

“The content of this substance differs in the samples of raw material and, most likely, its biosynthesis depends on the amount of calcium in the soil. For pharmaceutical purposes, it is advisable to use calcium chelidonate obtained by a semisynthetic method,” explained Elena Avdeeva, candidate of pharmaceutical sciences, researcher, Siberian State Medical University

An X-ray analysis confirmed that the substance has a structure identical to a natural compound. Researchers tested the effect of the substance in vitro and in vivo: it promoted the conversion of human stem cells derived from adipose tissue (hAMMSC) and mouse mesenchymal stromal cells into osteoblasts respectively. 

Calcium chelidonate is non-toxic and promotes bone regeneration: in vitro studies have shown that a dose of only 10mg/L increases the number of viable stem cells. Titanium implants coated with calcium phosphate and bearing autologous bone marrow were introduced into mice. The researchers found that calcium chelidonate stimulated the growth of new bone on the surface of the implant with daily administration of the drug for 35 days.

“The use of substances with osteoprotective properties, in particular, calcium chelidonate, is promising for the treatment of several diseases associated with bone defects or bone metabolism disorders. We are considering the development of a pharmaceutical form of the substance and its introduction into practical medicine,” concluded Larisa Litvinova, Doctor of Medicine, professor, head of the laboratory of immunology and cellular biotechnology at the IKBFU.

Source: News-Medical.Net

Journal information: Avdeeva, E., et al. (2021) Calcium Chelidonate: Semi-Synthesis, Crystallography, and Osteoinductive Activity In Vitro and In Vivo. Pharmaceuticals. doi.org/10.3390/ph14060579.

Bone Loss Linked to Cognitive Decline in Women

Photo by Miikka Luotio on Unsplash
Photo by Miikka Luotio on Unsplash

Researchers  have discovered a link between cognitive decline and accelerated bone loss, and found that cognitive decline over five years increased future fracture risk in women. There was a less strong association in men.

The 16-year study enrolling individuals aged 65 and over was led by the Garvan Institute of Medical Research and , and has uncovered a potential new approach to help identify older people who may be at risk of fracture.
“Bone loss and cognitive decline are major public health issues, but both are ‘silent diseases’ that can go undetected and untreated for long periods, often until the conditions are severely progressed,” says Professor Jacqueline Center, Head of the Clinical Studies and Epidemiology lab at Garvan, endocrinologist at St Vincent’s Hospital and senior author of the findings published in the Journal of Bone and Mineral Research.

“Our study has revealed a link between the two in women, which suggests that cognition should be monitored together with bone health, as a decline in one could mean a decline in the other. These findings may help refine best practice guidelines of how cognition and bone health are monitored in older age, to ensure appropriate treatment can be more effectively administered.”

A growing problem with an ageing population

Osteoporosis affects some 200 million people worldwide, and more than 35 million for dementia — numbers set to double over the next 20 years due to rising life expectancy.

“Cognitive decline and bone loss both result in increased disability, loss of independence and an increased risk of mortality. There is some evidence that older individuals with dementia have a higher risk of hip fractures, but whether the decline of both bone and cognitive health are linked over time has not been studied,” said first author Dr Dana Bliuc from the Garvan Institute.

“We set out to understand the long-term association, with our study the first to investigate both cognitive and bone health data over more than 15 years.”

Data was drawn from the Canadian Multicentre Osteoporosis Study (CaMos), which has monitored skeletal health in community-dwelling people since 1995. The researchers examined cognitive and bone health measurements of 1741 women and 620 men aged 65 years and older, who were free of cognitive decline symptoms at the study outset.

Cognition link to bone health

“After adjusting for all other variables, we observed a significant link between a decline in cognitive health and bone loss in women. This association was weaker and not statistically significant in men,” said Dr Bliuc.

“Interestingly, we also saw that cognitive decline over the first five years was associated with a 1.7-fold increase in future fracture risk in women in the subsequent 10 years. This was independent of the level of bone loss,” Dr Bliuc added.

“While this study could not identify a causal link – whether a decline in cognitive function leads to a decline in bone loss, or vice versa – it suggests that cognitive decline should be monitored along with bone health, as a decline in one may signal the need for increased vigilance in the other,” said Professor Center.

The researchers add that the link could potentially be mediated by a third factor, such as oestrogen deficiency, linked to bone loss and cognitive decline. This research also opens the door for additional studies into what the link between these two common conditions may be.

“What our study highlights is that cognitive health is potentially an important factor for providing more information to individuals and their health professionals on fracture risk, and ultimately improve health outcomes for our older population,” said Professor Center.

Source: Garvan Institute of Medical Research

Journal information: Bliuc, D., et al. (2021) Cognitive decline is associated with an accelerated rate of bone loss and increased fracture risk in women: a prospective study from the Canadian Multicentre Osteoporosis Study. Journal of Bone & Mineral Research. doi.org/10.1002/jbmr.4402.

New Insights into What Stimulates Bone Growth

Photo by Nino Liverani on Unsplash
Photo by Nino Liverani on Unsplash

Researchers have discovered some new insights into how bone mass is maintained and how physical load stimulates bone growth.

Researchers from the National Cerebral and Cardiovascular Center Research Institute in Japan have revealed that the expression of the peptide osteocrin (OSTN) is influenced by load – decreasing when load is reduced, and increasing when it is added. Their study was published in Cell Reports.

Bones and skeletal muscles are strengthened by loads produced in exercise, preventing bone and muscle atrophy, and maintaining bone and muscle strength is important for maintaining physical activity. The growth of long bones, such as the femur and tibia, is a very complex process controlled by genetic and environmental factors, such as exercise and gravity.

Understanding bone loss would help retain bone density and strength in people who are unable to exercise due to immobility, the elderly, as well as astronauts in spaceflight.

Study lead author Haruko Watanabe-Takano said, “Not much is known about how mechanical force initiates biochemical signals to control bone growth. We investigated how load is related to the metabolic balance adjustment of bone maintenance.”

Bone mass and strength is maintained by the balanced activities of two types of cells – the bone-genearting osteoblasts, and the bone-dissolving osteoclasts – and is thought to be made in response to load demand. Specifically, the team investigated the expression of OSTN, a peptide produced by osteoblasts, in mice. OSTN is critical to the regulation of bone growth, as well as physical endurance.

The researchers found that OSTN was very strongly expressed in bones such as the tibia, radius, and ulna, and in regions experiencing load. They determined that OSTN was secreted by the periosteal osteoblasts in these bones. The periosteum is a fibrous membrane that covers nearly every bone in the body, except for the joints of the long bones. This tissue has a major role in bone growth and bone repair and has an impact on the blood supply of bone as well as skeletal muscle. Despite its importance, it has received little attention in the literature and in some ways is not well understood.

“We also found that OSTN expression decreased when load was reduced, and was increased by load stimulation,” says Watanabe-Takano. “Moreover, when we genetically engineered mice lacking OSTN, we found that they had reduced bone mass compared with normal mice and lacked load-induced recovery of bone mass after prolonged load reduction. Thus, we concluded that OSTN makes bone in response to stimulation by load, promoting bone formation.”

The team found that to create this effect, OSTN increases levels of another peptide, called C natriuretic peptide, which in turn drives bone-forming osteoblasts to multiply, mature, and become functional.

The findings have implications for treatments for bed-ridden patients and others at risk of bone loss, such as the elderly. Further studies will explore issues such as how periosteal cells detect load stimulation.

Source: News-Medical.Net

Journal information: Watanabe-Takano, H., et al. (2021) Mechanical load regulates bone growth via periosteal Osteocrin. Cell Reports. doi.org/10.1016/j.celrep.2021.109380.

New Biomaterial Produced from Frog Skin and Fish Scales

Photo by Robert Zunikoff on Unsplash

Researchers at Nanyang Technological University, Singapore (NTU Singapore) have developed a new biomaterial made entirely from discarded bullfrog skin and fish scales that could help in bone repair.

The porous biomaterial, which contains the same compounds that are predominant in bones, acts as a scaffold for osteoblasts, or bone-forming cells, to adhere to and multiply, leading to new bone formation. Bone-forming cells successfully latched onto the biomaterial and started growing, and it was found to have a low inflammatory risk.

This kind of scaffold could help regenerate bone tissue lost to disease or injury, such as jaw defects from trauma or cancer surgery. It could also assist bone growth around surgical implants such as dental implants.

The current standard practice of using a patient’s own tissues means extra surgery is needed for bone extraction. The biomaterial used, frog skin and fish scales, are a significant waste stream produced by Singapore’s aquaculture industry and using them helps repurpose this waste.

‘Waste-to-resource’

“We took the ‘waste-to-resource’ approach in our study and turned discards into a high-value material with biomedical applications, closing the waste loop in the process,” said Dalton Tay, Assistant Professor, Nanyang Technological University. “Our lab studies showed that the biomaterial we have engineered could be a promising option that helps with bone repair. The potential for this biomaterial is very broad, ranging from repairing bone defects due to injury or ageing, to dental applications for aesthetics. Our research builds on NTU’s body of work in the area of sustainability and is in line with Singapore’s circular economy approach towards a zero-waste nation.”

To make the biomaterial, the team first extracted Type 1 tropocollagen (many molecules of which form collagen fibres) from the discarded skins of the American bullfrog and hydroxyapatite (a calcium-phosphate compound) from the scales of snakehead fish, commonly known as the Toman fish.

Collagen and hydroxyapatite (HA) are two predominant components found in bones, thus conferring on the biomaterial a structure, composition, and ability to promote cell attachment similar to bone, as well as toughness.

The scientists removed all impurities from the bullfrog skin, then blended it to form a thick collagenous paste that is diluted with water, from which collagen was extracted. “Using this approach, we were able to obtain the highest ever reported yield of collagen of approximately 70 per cent from frog skin, thus making this approach commercially viable,” said Asst Prof Tay, who is also from the NTU School of Biological Sciences (SBS).

HA was harvested from discarded fish scales through calcination – a purification process that requires high heat – to remove the organic matter, and then air-dried.

The biomaterial was synthesised by adding HA powder to the extracted collagen, then cast into a mould to make a 3D porous scaffold — a two-week process which the team believes can be shortened.

Testing the biomaterial

To assess the biological performance of the porous biomaterial scaffold for bone repair, the scientists seeded bone-forming cells onto the scaffold.

The cells proliferated, and after a week, the cells were uniformly distributed across the scaffold – an indicator that the scaffold could promote proper cellular activities and eventually lead to tissue formation. The scientists also found that the presence of HA in the biomaterial significantly enhanced bone formation.

The biomaterial was also tested for its tendency to cause an inflammatory response, which is common after a biomaterial is implanted in the body.

Using real-time polymerase chain reaction, the scientists found that the expression of pro-inflammatory genes in human immune cells exposed to the biomaterial stayed “relatively modest” compared to a control exposed to endotoxins, a compound known to stimulate immune response, said Asst Prof Tay.

For instance, the expression of the gene IL6 in the biomaterial group was negligible and at least 50 times lower than that of the endotoxins-exposed immune cells. This suggests that the risk of the NTU-developed biomaterial to trigger an excessive acute inflammatory response is low.

The team is now further evaluating the long-term safety and efficacy of the biomaterial as dental products. Further research would involve studying how the body responds to this biomaterial in the long term, as well its use in other applications such as skin wounds, along with further development of the waste-to-resource pipeline.

A preprint copy of the article is available as a PDF for download.

Source: Nanyang Technical University