Growing stem cells efficiently and preventing contamination is a major stumbling block in developing them for therapeutic applications. Still these days, animal byproducts are used in Petri dishes that grow stem cells, leading to infection that may trigger an immune response once these cells are transplanted into the body. To overcome this issue, researchers at University of Washington in Seattle have developed a 3 dimensional structure to serve as a nesting site for stem cells to comfortably grow and propagate.
Zhang's [Miqin Zhang, UW professor of materials science and engineering] cylindrical scaffold is made of chitosan, found in the shells of crustaceans, and alginate, a gelatinous substance found in algae. Chitosan and alginate have a structure similar to the matrix that surrounds cells in the body, to which cells can attach. Different processing techniques can make the scaffold out of interconnected pores of almost any size, Zhang said.Researchers first seeded the scaffold with 500,000 embryonic stem cells, and after 21 days the scaffold was completely saturated. The cells infiltrated the structure, Zhang added, unlike other materials where cells often grow only on the surface.
To retrieve the cells, researchers immersed the scaffold in a mild solution. The structure is biodegradable and so dissolved to release the stem cells. One also could implant the stem cell-covered scaffold directly into the body.
Analysis of gene activity and testing in the lab and in mice showed that the new stem cells retained the same properties as their predecessors.
Other researcher groups are also looking for alternatives to feeder layers. The leading contenders are scaffolds coated with custom proteins designed to mimic the key properties of the animal cells in the feeder layer. Such products are expensive and difficult to produce in a consistent manner, Zhang said. The proteins also get used up in a few days and have to be replaced, making them costly and time-consuming for everyday use.
"Our scaffold is made of natural materials that are already FDA-approved for food and biomedical applications. Also, these materials are unlimited, and the cost is cheap," she said.
Press release: 3-D scaffold provides clean, biodegradable structure for stem cell growth ...
Abstract in Biomaterials: Feeder-free self-renewal of human embryonic stemnext term cells in 3D porous natural polymer scaffolds
Images: Top: The UW's biodegradable scaffold was built as a cylinder which was then cut into dime-sized slices. Bottom: A magnified view of the scaffold shows the pores, each about a tenth of a millimeter wide, where stem cells can grow.
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A study out of Boston University School of Medicine, presented last week at the annual Triological Society meeting, has looked into the effectiveness of Medtronic's Slide-On Sensory Sheath as an alternative to germicidal immersion for flexible nasopharyngolaryngoscopes in between procedures. The condom-like device is wrapped over the fiber optic cable to prevent ENT scopes from getting dirty in the first place. The scope still requires an "enzymatic detergent cleaning and disinfection with 70 percent alcohol" when switching between patients, but the Slide-On should still save time during busy use of the scope.
Sonitus Medical out of San Mateo, California is a company that's betting on bone conducting dental hearing implant technology. The SoundBite Hearing System that the firm is developing consists of a unit that has a microphone and wireless transmitter, and a tiny speaker that attaches to rear teeth to resonate and transmit the audio mechanically to the cochleae. The idea for this technology is not new and maybe risky, but Sonitus Medical seems confident it can earn regulatory approval and introduce an all new hearing aid technology to market.
The X Prize Foundation recently announced that it's working on a new contest that will be offering $10 million to the winner to develop a breakthrough in brain-to-computer interface (BCI) technology. If the foundation comes up with adequate financing, it will be the same amount of buckaroos that they've been giving for advancements in commercial passenger space craft, automotive technology, DNA sequencing, and lunar travel. Although such BCI devices already kinda exist, they are functionally limited and don't lend themselves well to practical, especially clinical use. It is not yet known what the requirements of the Brain-Computer Interface X PRIZE will be, but considering the prize amount it should spur development in the field.
St. Jude Medical has received the European CE Mark of approval for the Fortify and Fortify ST implantable cardioverter defibrillators (ICD) and Unify cardiac resynchronization therapy defibrillator. The devices are smaller and can deliver a stronger punch than previous generation models, and they feature new heart monitoring algorithms.
New cancer targeting nanoparticles seem like daily news here at Medgadget. Today we have gold nanoparticles developed jointly by researchers at Rice University and A.V. Lykov Heat and Mass Transfer Institute in Minsk, Belarus that create plasmonic nanobubbles when targeted with a laser. These particles can be guided to a tumor by antibodies and then activated to generate tiny explosions, so clinicians one day will be able to stay back and enjoy.
Clinical researchers at Cambridge University have been testing the effectiveness of combining commercial continuous glucose monitors with insulin pumps via a proprietary closed-loop algorithm developed by the researchers.. The study, performed on type 1 diabetic pediatric patients using pumps and meters from Smiths Medical, Medtronic, and Abbott, has demonstrated a significant overnight glucose management improvement over continuous drip pumps.
An internationalist team of researchers has just successfully finished the first human trials of a new malaria vaccine. Tested on 100 West African children susceptible to malaria, the trial showed a high level of relevant antibodies a year after the vaccine was administered.