:: Posted by American Biotechnologist on 09-10-2013
A team of researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University has found a way to self-assemble complex structures out of bricks smaller than a grain of salt. The self-assembly method could help solve one of the major challenges in tissue engineering: regrowing human tissue by injecting tiny components into the body that then self-assemble into larger, intricately structured, biocompatible scaffolds at an injury site.
The key to self-assembly was developing the world’s first programmable glue. The glue is made of DNA, and it directs specific bricks of a water-filled gel to stick only to each other, the scientists report in the September 9th online issue of Nature Communications.
“By using DNA glue to guide gel bricks to self-assemble, we’re creating sophisticated programmable architecture,” says Peng Yin, Ph.D., a Core Faculty member at the Wyss Institute and senior coauthor of the study, who is also an Assistant Professor of Systems Biology at Harvard Medical School. This novel self-assembly method worked for gel bricks from as small as a speck of silt (30 microns diameter) to as large as a grain of sand (1 millimeter diameter), underscoring the method’s versatility.
:: Posted by American Biotechnologist on 09-02-2013
Ever since Darwin, biologists have been puzzled about why there is so much apparent cooperation, and even flat-out generosity and altruism, in nature
-Associate Professor Joshua B. Plotkin, University of Pennsylvania Biologist
With new insights into the classical game theory match-up known as the “Prisoner’s Dilemma,” University of Pennsylvania biologists offer a mathematically based explanation for why cooperation and generosity have evolved in nature.
Their work builds upon the seminal findings of economist John Nash, who advanced the field of game theory in the 1950s, as well as those of computational biologist William Press and physicist-mathematician Freeman Dyson, who last year identified a new class of strategies for succeeding in the Prisoner’s Dilemma.
Postdoctoral researcher Alexander J. Stewart and associate professor Joshua B. Plotkin, both of Penn’s Department of Biology in the School of Arts and Sciences, examined the outcome of the Prisoner’s Dilemma as played repeatedly by a large, evolving population of players. While other researchers have previously suggested that cooperative strategies can be successful in such a scenario, Stewart and Plotkin offer mathematical proof that the only strategies that succeed in the long term are generous ones. They report their findings in PNAS the week of Sept. 2.
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:: Posted by American Biotechnologist on 08-21-2013
Often, it is easy to get caught up studying the “movers and shakers” of our favorite biological system while tragically ignoring the role of a smaller player and wrongfully endowing it with the title of an “unimportant” molecule. Yet until every biological nook and cranny are uncovered, nothing should ever be dismissed as irrelevant.
Researchers at the University of Pennsylvania had a chance to demonstrate this principle recently as they revealed that a scarce, small RNA, called U6atac, controls the expression of hundreds of genes that have critical functions in cell growth, cell-cycle control, and global control of physiology.
While the major spliceosomes that control the process of removing the majority of introns from mRNA prior to their translation into protein have been studied for years, few scientists have ventured into the world of the minor spliceosome as it was thought to only control the post-transcriptional processing of very few mRNA molecules. Bucking the trend, Dr. Gideon Dreyfuss and his team from U Penn concentrated their efforts on studying the role of the minor spliceosomes and their results have revealed an heretofore undiscovered mechanism responsible for controlling the expression of hundreds of human genes.
To learn more read A Minor Thing of Major Importance: Penn Study Finds A New Gene Expression Mechanism.
:: Posted by American Biotechnologist on 08-12-2013
Scientists have been using Adeno-associated viruses (AAVs) as a gene therapy vector for a number of years. Depite the fact that there are over 80 clinical trials that involve the use of AAVs worldwide (Wikipedia), AAVs lack the stability and specificity to deliver a gene to a specific target such as particular subregions of the brain.
In a new study taking place at Rice University, researchers have made use of computational and bioengineering methods to create new, benign viruses that can deliver DNA payloads to specific cells.
Their technique is premised upon an algorithm that predicts how parts of very large viruses can recombine by homing in on the viral protein sequences that work well together. According to senior scientist Jonathan Silberg, the researchers are using a hybrid approach to design and select the ideal mix of viruses which will deliver its gene payload in the most efficient manner.
“We’re treating them like Legos,” Silberg said. “We’re taking distantly related viruses that nature might not recombine very efficiently and looking for self-contained pieces of these proteins that can be swapped.”
To read more about this story see Rice writes rules for gene-therapy vectors.