User login
Louis Heiser & Robert Ackland
A new hydrogel improves on previous models by enabling the generation of more mature blood vessels, according to research published in ACS Nano.
The hydrogel also overcomes several other issues that have kept previous hydrogels from reaching their potential to treat injuries and forming new vasculature to treat heart attack, stroke, and ischemic tissue diseases.
Like earlier versions, the new hydrogel can be injected in liquid form and turns into a nanofiber-infused gel at the site of the injury. The difference with this hydrogel, according to researchers, is the quality of the blood vessels that are formed.
This hydrogel is made of self-assembling synthetic peptides that form nanofiber scaffolds. And the peptides incorporate a mimic of vascular endothelial growth factor, a signal protein that promotes angiogenesis.
Furthermore, the hydrogel can be easily delivered by syringe, is quickly infiltrated by hematopoietic and mesenchymal cells, and quickly forms a mature vascular network.
“In a lot of the published literature, you see rings that only have the endothelial cell lining, and that indicates a very immature blood vessel,” said study author Jeffrey Hartgerink, PhD, of Rice University in Houston, Texas.
“These types of vessels usually don’t persist and disappear shortly after they show up. In ours, you see that same endothelial cell layer, but surrounding it is a smooth muscle cell layer that indicates a much more mature vessel that’s likely to persist.”
Furthermore, the scaffolds the hydrogel forms show no signs of fibrous encapsulation. After 3 weeks, they are resorbed into the native tissue.
In previous studies, implanted synthetic materials tended to become encapsulated by fibrous barriers that kept cells and blood vessels from infiltrating the scaffold, Dr Hartgerink said.
“That is an extremely common problem in synthetic materials put into the body,” he explained. “Some avoid this problem, but if the body doesn’t like a material and isn’t able to destroy it, the solution is to wall it off.”
“As soon as that happens, the flow of nutrients across that barrier decreases to almost nothing. So the fact that we’ve developed syringe-directed delivery of a material that doesn’t develop fibrous encapsulation is really important.”
Other negative characteristics of earlier hydrogels—unwanted immune responses, surface degradation preceding their integration into biological systems, and the release of artificial degradation byproducts—have been eliminated as well, Dr Hartgerink said.
“There are a lot of features about this hydrogel that come together to make it a unique system,” he added. “If you look through the literature at what other people have done, each concept that is involved in our system probably exists somewhere already. The difference is that we have all these features in one place working together.” 
Louis Heiser & Robert Ackland
A new hydrogel improves on previous models by enabling the generation of more mature blood vessels, according to research published in ACS Nano.
The hydrogel also overcomes several other issues that have kept previous hydrogels from reaching their potential to treat injuries and forming new vasculature to treat heart attack, stroke, and ischemic tissue diseases.
Like earlier versions, the new hydrogel can be injected in liquid form and turns into a nanofiber-infused gel at the site of the injury. The difference with this hydrogel, according to researchers, is the quality of the blood vessels that are formed.
This hydrogel is made of self-assembling synthetic peptides that form nanofiber scaffolds. And the peptides incorporate a mimic of vascular endothelial growth factor, a signal protein that promotes angiogenesis.
Furthermore, the hydrogel can be easily delivered by syringe, is quickly infiltrated by hematopoietic and mesenchymal cells, and quickly forms a mature vascular network.
“In a lot of the published literature, you see rings that only have the endothelial cell lining, and that indicates a very immature blood vessel,” said study author Jeffrey Hartgerink, PhD, of Rice University in Houston, Texas.
“These types of vessels usually don’t persist and disappear shortly after they show up. In ours, you see that same endothelial cell layer, but surrounding it is a smooth muscle cell layer that indicates a much more mature vessel that’s likely to persist.”
Furthermore, the scaffolds the hydrogel forms show no signs of fibrous encapsulation. After 3 weeks, they are resorbed into the native tissue.
In previous studies, implanted synthetic materials tended to become encapsulated by fibrous barriers that kept cells and blood vessels from infiltrating the scaffold, Dr Hartgerink said.
“That is an extremely common problem in synthetic materials put into the body,” he explained. “Some avoid this problem, but if the body doesn’t like a material and isn’t able to destroy it, the solution is to wall it off.”
“As soon as that happens, the flow of nutrients across that barrier decreases to almost nothing. So the fact that we’ve developed syringe-directed delivery of a material that doesn’t develop fibrous encapsulation is really important.”
Other negative characteristics of earlier hydrogels—unwanted immune responses, surface degradation preceding their integration into biological systems, and the release of artificial degradation byproducts—have been eliminated as well, Dr Hartgerink said.
“There are a lot of features about this hydrogel that come together to make it a unique system,” he added. “If you look through the literature at what other people have done, each concept that is involved in our system probably exists somewhere already. The difference is that we have all these features in one place working together.”
Louis Heiser & Robert Ackland
A new hydrogel improves on previous models by enabling the generation of more mature blood vessels, according to research published in ACS Nano.
The hydrogel also overcomes several other issues that have kept previous hydrogels from reaching their potential to treat injuries and forming new vasculature to treat heart attack, stroke, and ischemic tissue diseases.
Like earlier versions, the new hydrogel can be injected in liquid form and turns into a nanofiber-infused gel at the site of the injury. The difference with this hydrogel, according to researchers, is the quality of the blood vessels that are formed.
This hydrogel is made of self-assembling synthetic peptides that form nanofiber scaffolds. And the peptides incorporate a mimic of vascular endothelial growth factor, a signal protein that promotes angiogenesis.
Furthermore, the hydrogel can be easily delivered by syringe, is quickly infiltrated by hematopoietic and mesenchymal cells, and quickly forms a mature vascular network.
“In a lot of the published literature, you see rings that only have the endothelial cell lining, and that indicates a very immature blood vessel,” said study author Jeffrey Hartgerink, PhD, of Rice University in Houston, Texas.
“These types of vessels usually don’t persist and disappear shortly after they show up. In ours, you see that same endothelial cell layer, but surrounding it is a smooth muscle cell layer that indicates a much more mature vessel that’s likely to persist.”
Furthermore, the scaffolds the hydrogel forms show no signs of fibrous encapsulation. After 3 weeks, they are resorbed into the native tissue.
In previous studies, implanted synthetic materials tended to become encapsulated by fibrous barriers that kept cells and blood vessels from infiltrating the scaffold, Dr Hartgerink said.
“That is an extremely common problem in synthetic materials put into the body,” he explained. “Some avoid this problem, but if the body doesn’t like a material and isn’t able to destroy it, the solution is to wall it off.”
“As soon as that happens, the flow of nutrients across that barrier decreases to almost nothing. So the fact that we’ve developed syringe-directed delivery of a material that doesn’t develop fibrous encapsulation is really important.”
Other negative characteristics of earlier hydrogels—unwanted immune responses, surface degradation preceding their integration into biological systems, and the release of artificial degradation byproducts—have been eliminated as well, Dr Hartgerink said.
“There are a lot of features about this hydrogel that come together to make it a unique system,” he added. “If you look through the literature at what other people have done, each concept that is involved in our system probably exists somewhere already. The difference is that we have all these features in one place working together.”