Silk Biomaterials Produced from 3D Bone Marrow Generate Platelets
Reported by: Irina Robu, PhD
The team used silk protein scaffolds that silk is a very biocompatible material that is amenable to many manipulations to customize it for a specific use, while also avoiding any cell-specific signaling. They formed silk scaffolds with thickness ranging from 2 to 5 micrometers and stiffness combined with growth factors, to test the success of megakaryocyte adhesion and the formation of pro-platelets—the parts of the megakaryocytes that fragment into platelets. After determining the best combination of scaffolds with appropriate thickness and stiffness, the researchers attached the silk scaffolds to a plastic framework to guide the growth of cells. The next step is to grow endothelial primary cells on one side of the silk scaffold and megakaryocytes on the other side, partly because endothelial primary cells are known to secrete growth factors that help megakaryocytes mature.
In order to mimic the microvasculature and environment, the researchers form silk sponges around the porous microtubes. The culture media with necessary nutrients is being pumped to mimic the flow of blood which leads to higher numbers of platelets generated than was previously possible; and most importantly, the platelets were functional.This is the first time researchers were able to create the complete micro environment where platelets are formed.
This is very insightful. There is no doubt that there is the bias you refer to. 42 years ago, when I was postdocing in biochemistry/enzymology before completing my residency in pathology, I knew that there were very influential mambers of the faculty, who also had large programs, and attracted exceptional students. My mentor, it was said (although he was a great writer), could draft a project on toilet paper and call the NIH. It can’t be true, but it was a time in our history preceding a great explosion. It is bizarre for me to read now about eNOS and iNOS, and about CaMKII-á, â, ã, ä – isoenzymes. They were overlooked during the search for the genome, so intermediary metabolism took a back seat. But the work on protein conformation, and on the mechanism of action of enzymes and ligand and coenzyme was just out there, and became more important with the research on signaling pathways. The work on the mechanism of pyridine nucleotide isoenzymes preceded the work by Burton Sobel on the MB isoenzyme in heart. The Vietnam War cut into the funding, and it has actually declined linearly since.
A few years later, I was an Associate Professor at a new Medical School and I submitted a proposal that was reviewed by the Chairman of Pharmacology, who was a former Director of NSF. He thought it was good enough. I was a pathologist and it went to a Biochemistry Review Committee. It was approved, but not funded. The verdict was that I would not be able to carry out the studies needed, and they would have approached it differently. A thousand young investigators are out there now with similar letters. I was told that the Department Chairmen have to build up their faculty. It’s harder now than then. So I filed for and received 3 patents based on my work at the suggestion of my brother-in-law. When I took it to Boehringer-Mannheim, they were actually clueless.