Coated tissue scaffolds help the body grow new bone to repair injuries or congenital defects.
MIT chemical engineers have devised a new implantable tissue scaffold coated with bone growth factors that are released slowly over a few weeks. When applied to bone injuries or defects, this coated scaffold induces the body to rapidly form new bone that looks and behaves just like the original tissue.
This type of coated scaffold could offer a dramatic improvement over the current standard for treating bone injuries, which involves transplanting bone from another part of the patient’s body — a painful process that does not always supply enough bone. Patients with severe bone injuries, such as soldiers wounded in battle; people who suffer from congenital bone defects, such as craniomaxillofacial disorders; and patients in need of bone augmentation prior to insertion of dental implants could benefit from the new tissue scaffold, the researchers say.
“It’s been a truly challenging medical problem, and we have tried to provide one way to address that problem,” says Nisarg Shah, a recent PhD recipient and lead author of the paper, which appears in the Proceedings of the National Academy of Sciences this week.
Paula Hammond, the David H. Koch Professor in Engineering and a member of MIT’s Koch Institute for Integrative Cancer Research and Department of Chemical Engineering, is the paper’s senior author. Other authors are postdocs M. Nasim Hyder and Mohiuddin Quadir, graduate student Noémie-Manuelle Dorval Courchesne, Howard Seeherman of Restituo, Myron Nevins of the Harvard School of Dental Medicine, and Myron Spector of Brigham and Women’s Hospital.
Stimulating bone growth
Two of the most important bone growth factors are platelet-derived growth factor (PDGF) and bone morphogenetic protein 2 (BMP-2). As part of the natural wound-healing cascade, PDGF is one of the first factors released immediately following a bone injury, such as a fracture. After PDGF appears, other factors, including BMP-2, help to create the right environment for bone regeneration by recruiting cells that can produce bone and forming a supportive structure, including blood vessels.
Efforts to treat bone injury with these growth factors have been hindered by the inability to effectively deliver them in a controlled manner. When very large quantities of growth factors are delivered too quickly, they are rapidly cleared from the treatment site — so they have reduced impact on tissue repair, and can also induce unwanted side effects.
“You want the growth factor to be released very slowly and with nanogram or microgram quantities, not milligram quantities,” Hammond says. “You want to recruit these native adult stem cells we have in our bone marrow to go to the site of injury and then generate bone around the scaffold, and you want to generate a vascular system to go with it.”
This process takes time, so ideally the growth factors would be released slowly over several days or weeks. To achieve this, the MIT team created a very thin, porous scaffold sheet coated with layers of PDGF and BMP. Using a technique called layer-by-layer assembly, they first coated the sheet with about 40 layers of BMP-2; on top of that are another 40 layers of PDGF. This allowed PDGF to be released more quickly, along with a more sustained BMP-2 release, mimicking aspects of natural healing.
“This is a major advantage for tissue engineering for bones because the release of the signaling proteins has to be slow and it has to be scheduled,” says Nicholas Kotov, a professor of chemical engineering at the University of Michigan who was not part of the research team.
The scaffold sheet is about 0.1 millimeter thick; once the growth-factor coatings are applied, scaffolds can be cut from the sheet on demand, and in the appropriate size for implantation into a bone injury or defect.
The Latest on: Bone repair
via Google News
The Latest on: Bone repair
- Helping Injured Pigeons Fly Again With Dog and Sheep Boneson November 20, 2019 at 8:58 pm
They typically use metal pins, which is standard for these types of procedures, but they noticed imbalances in the flight, take off, or landings after fracture repair. Therefore, they wanted a ...
- Bone Harvester Market Examination and Industry Growth Till 2025 Which Is Going to Change Industry Futureon November 20, 2019 at 8:33 am
Based on application, the global bone harvester market can be classified into fractures, fusions, bone repair, and others. In terms of surgery type, the market can be bifurcated into open surgery and ...
- Dog and sheep bones help injured pigeons fly againon November 20, 2019 at 8:04 am
Sheep and dog bones can be whittled into orthopedic pins that stabilize pigeons' fractured wings, helping the fractures to heal properly without follow-up surgery. Researchers describe the ...
- Pet Talk | A new treatment for broken boneson November 18, 2019 at 8:03 am
Deuces, whose femur was fractured when he was hit by a truck, is on the mend thanks to the new I-Loc system for repairing broken bones. Dr. Danielle Marturello, a clinical assistant professor of ...
- In vivo Labeling of Bone Microdamage in an Animal Model of Type 1 Diabetes Mellituson November 18, 2019 at 2:06 am
The mineral apposition rate i.e the rate at which mineral accretion occurs at a remodeling site during the period of bone formation was depressed in all diabetic samples compared to the controlled ...
- Augmented Bone Graft Market Global Analysis by Industry Outlook, Estimated Size, Valuable Share, Current Demand and Future Trends, Foreseen 2023on November 15, 2019 at 6:26 am
Bone grafting is known as a surgical procedure that is known for its effective handling of replacing missing bone or to repair bone fracture. The process requires extremely complex handling of the ...
- Bone loss and some other lesser known complications that accompany diabeteson November 15, 2019 at 5:41 am
They say that ‘diabetic patients often experience low bone density. This has an association with an increase in the risk of bone fractures and delay in fracture repair’. They came to this conclusion ...
- Bone Therapeutics (EBR:BOTHE) Is Carrying A Fair Bit Of Debton November 14, 2019 at 11:52 pm
Of course, Bone Therapeutics has a market capitalization ... So we think its balance sheet is a little strained, though not beyond repair. However, it doesn't help that it burned through € ...
- In vivo changes of nanoapatite crystals during bone reconstruction and the differences with native bone apatiteon November 13, 2019 at 11:08 am
3 Department of Biomedical Engineering, College of Engineering, Peking University, Beijing 100871, China. Hydroxyapatite (HA) plays an important role in clinical bone repair. However, it remains a ...
- Bone Grafts Market: Global Market Opportunity Analysis, Competitor Landscape, Growth, Trends and Forecast 2019-2025on November 13, 2019 at 4:16 am
Nov 13, 2019 (WiredRelease via COMTEX) -- Bone grafting is a surgical procedure used to fix the bones or joints. Bone grafting is replacement or repair of bones which are damaged due to trauma or ...
via Bing News