How to Repair Damaged Bones

Over the last 30 years, the scientific community has been working to develop a synthetic alternative to bone grafts for repairing diseased or damaged bone. McGill University researchers used the Canadian Light Source (CLS) at the University of Saskatchewan to advance a novel method for growing synthetic bone tissue. The rapidly advancing field of  tissue engineering is focused on growing bone  in the lab on materials called scaffolds, then transferring these structures into a person’s body to repair bone damage. Like the bone it mimics, scaffolds need an interconnected network of small and large pores that allow cells and nutrients to spread and help generate new bone tissue. The McGill team’s promising process works by modifying the internal structure of a material, called , to make it more conducive to regenerating bone tissue.

Graphene oxide is an ultrathin, extra strong compound that is being used increasingly in electronics, optics, chemistry, energy storage, and biology. One of its  is that when  are placed on it, they tend to transform into bone-generating cells called osteoblasts. The multidisciplinary group—comprising researchers from McGill‘s Departments of Mining and Materials Engineering, Electrical Engineering, and Dentistry—found that adding an emulsion of oil and water to the graphene oxide, then freezing it at two different temperatures, yielded two different sizes of pores throughout the material.Professor Marta Cerruti said that when they “seeded” the now-porous scaffolding with stem cells from mouse bone marrow, the cells multiplied and spread inside the network of pores, a promising sign the new approach could eventually be used to regenerate bone tissue in humans.

We showed that the scaffolds are completely biocompatible, that the cells are happy when you put them in there, and that they’re able to penetrate all through the scaffold and colonize the whole scaffold,” she stated.

The researchers used the BMIT-BM beamline at the CLS to visualize the different sized pores inside the scaffolding as well as the growth and spread of the cells. Lead researcher Yiwen Chen, a Ph.D. student working under Cerruti, said their work would not have been possible without the synchrotron because the low density of graphene oxide means it absorbs only a very small amount of light.

To our knowledge, this is the first time that people have used synchrotron light to see the structure of graphene oxide scaffolds,” said Chen.

Source: https://phys.org/

How to Rebuild Bone Tissue

The rapidly advancing field of  tissue engineering is focused on growing bone  in the lab on materials called scaffolds, then transferring these structures into a person’s body to repair bone damage. Like the bone it mimics, scaffolds need an interconnected network of small and large pores that allow cells and nutrients to spread and help generate new bone tissue.

The McGill team’s promising process works by modifying the internal structure of a material, called , to make it more conducive to regenerating bone tissueGraphene oxide is an ultrathin, extra strong compound that is being used increasingly in electronics, optics, chemistry, energy storage, and biology. One of its  is that when  are placed on it, they tend to transform into bone-generating cells called osteoblasts.

The multidisciplinary group—comprising researchers from McGill‘s Departments of Mining and Materials Engineering, Electrical Engineering, and Dentistry—found that adding an emulsion of oil and water to the graphene oxide, then freezing it at two different temperatures, yielded two different sizes of pores throughout the material.

Professor Marta Cerruti said that when they “seeded” the now-porous scaffolding with stem cells from mouse bone marrow, the cells multiplied and spread inside the network of pores, a promising sign the new approach could eventually be used to regenerate bone tissue in humans.

We showed that the scaffolds are completely biocompatible, that the cells are happy when you put them in there, and that they’re able to penetrate all through the scaffold and colonize the whole scaffold,” she stated.

Source: https://phys.org/

Solar-driven Water Splitting Catalyst Produces Hydrogen

Engineers from Lehigh University (Bethlehem, Pennsylvania)  are the first to utilize a single enzyme biomineralization process to create a catalyst that uses the energy of captured sunlight to split water molecules to produce hydrogen. The synthesis process is performed at room temperature and under ambient pressure, overcoming the sustainability and scalability challenges of previously reported methods.

Solar-driven water splitting is a promising route towards a renewable energy-based economy. The generated hydrogen could serve as both a transportation fuel and a critical chemical feedstock for fertilizer and chemical production. Both of these sectors currently contribute a large fraction of total greenhouse gas emissions.

One of the challenges to realizing the promise of solar-driven energy production is that, while the required water is an abundant resource, previously-explored methods utilize complex routes that require environmentally-damaging solvents and massive amounts of energy to produce at large scale. The expense and harm to the environment have made these methods unworkable as a long-term solution.

Now a team of engineers at Lehigh have harnessed a biomineralization approach to synthesizing both quantum confined nanoparticle metal sulfide particles and the supporting reduced graphene oxide material to create a photocatalyst that splits water to form hydrogen. The team reported their results in an article entitled: “Enzymatic synthesis of supported CdS quantum dot/reduced graphene oxide photocatalysts” featured on the cover of the August 7 issue of Green Chemistry, a journal of the Royal Society of Chemistry. “Our water-based process represents a scalable green route for the production of this promising photocatalyst technology,” says Professor Steven McIntosh, who is also associate director of Lehigh’s Institute for Functional Materials and Devices.

Source: https://engineering.lehigh.edu/

Using Graphene, Munitions Go Further, Much Faster

Researchers from the U.S. Army and top universities discovered a new way to get more energy out of energetic materials containing aluminum, common in battlefield systems, by igniting aluminum micron powders coated with graphene oxide.

This discovery coincides with the one of the Army‘s modernization priorities: Long Range Precision Fires. This research could lead to enhanced energetic performance of metal powders as propellant/explosive ingredients in Army’s munitions.

Lauded as a miracle material, graphene is considered the strongest and lightest material in the world. It’s also the most conductive and transparent, and expensive to produce. Its applications are many, extending to electronics by enabling touchscreen laptops, for example, with light-emitting diode, or LCD, or in organic light-emitting diode, or OLED displays and medicine like DNA sequencing. By oxidizing graphite is cheaper to produce en masse. The result: graphene oxide (GO).

Scanning electron micrograph shows the Al/GO composite.

Although GO is a popular two-dimensional material that has attracted intense interest across numerous disciplines and materials applications, this discovery exploits GO as an effective light-weight additive for practical energetic applications using micron-size aluminum powders (µAl), i.e., aluminum particles one millionth of a meter in diameter.

The research team published their findings in the October edition of ACS Nano with collaboration from the RDECOM Research Laboratory, the Army’s corporate research laboratory (ARL), Stanford University, University of Southern California, Massachusetts Institute of Technology and Argonne National Laboratory.

Source: https://www.arl.army.mil/