It’s challenging enough for the bird flu virus to move to humans to make the emergence of new strains of the human influenza relatively rare. However, once the virus has managed to cross the species barrier, it is often able to do significant damage, with many strains causing a high mortality rate. Recently, researchers have zeroed in on what turns out to be a very limited route through which avian influenza is able to cross from birds to man, a discovery that might one day prevent the species-crossing altogether. The research study conducted by scientists at Imperial College London looked into just what changes to the virus mediate their ability to infiltrate mammalian cells, with the aim of pinpointing a new pharmaceutical target that could potentially prevent the influenza infection from replicating in humans. The study involved the insertion of various fragments of chicken DNA into mammalian hamster cells to try and discover exactly where as well as how the infection was able to replicate. By observing in which cells the virus was able to take hold, the team were eventually able to identify the ANP32A protein as a potential candidate. ANP32A is a protein that also exists in a slightly different form in mammals including people. What the researchers discovered was that only when the bird influenza viral ANP32A-binding protein changed its molecular structure to a form that can also bind to mammalian form of ANP32A was the virus able to replicate within mammalian cells. This provides an important new target for the pharmaceutical industry to go after to combat the emergence of new strains of avian influenza and might also one day prevent the spread of the more common human influenzas that infect 800 million humans each year.
Researchers are more and more relying on nanotechnology to develop new strategies in the fight against cancer, but one such technique under experimentation at North Carolina State University (NCSU) takes its cue directly from Hollywood. The NCSU scientists have produced “Nano-Terminators” which are liquid metal particles that specifically attack tumour cells. The procedure starts with gallium indium alloy, a liquid metal the group have previously shown capable of changing its shape through changes in its surface tension. In this study, the team combined the metal alloy with 2 kinds of ligand molecules and used ultrasound to split the liquid metal into small 100nm beads which then bound to the two types of ligands. An oxidised layer of metal formed around the liquid metal beads preventing them from binding back together again. Following this, doxorubicin, a drug used in cancer therapy, was then blended into the mixture. One of the ligand molecule types attached to the cancer medicine, while the other ligand was responsible for pinpointing the tumour cells so that its toxic contents can be delivered to the intended target. Using mice that develop cancer, the group demonstrated that the Nano-Terminators were taken in by their malignant tumours cells and were disrupted by the acidity inside the cells. This resulted in the discharge of the doxorubicin, killing the malignant tumours cells with little or no collateral toxicity. Arnold would be so proud!
Scientists at the Salk Institute in California have recently tested a developmental drug designed to combat the signs of old age which are directly correlated with Alzheimer’s disease. Using the memory-enhancing J147 compound, which was originally synthesised after examining age-related accumulations in the brain and shown to prevent memory loss in inherited Alzheimer’s, the scientists were able to also show positive effects in rodents that have a predisposition to age quickly. By determining its impact on their brain genes, in addition to its effect on several hundred molecules associated with the metabolic process, the scientists sought to uncover whether the developmental drug was as beneficial at combating Alzheimer’s caused by old age as it was in the inherited form, and they were not disappointed. According to a number of physiological measures, the J147-treated group of mice resembled younger rodents, doing much better in memory tests as well as demonstrating improved motor functionalities, while their brains revealed fewer pathological characteristics of Alzheimer’s than the control group. They even exhibited a ‘younger’ gene expression profile and had metabolic activity that were more akin to those of younger mice. The researchers now hope to begin human clinical trials in the coming year.
Many people unfortunate enough to have diabetes also have to suffer the negative consequences of having to have insulin shots every day. Yet this could be about to change with a new insulin strip that is being developed that affixes to the intestinal tract wall surface and discharges its hormone after being ingested. Orally-administered insulin is nothing new but it has always been difficult to achieve in practice due to its susceptibility to digestive system enzymes that degrade the hormone before sufficient amounts of it have been absorbed. Yet researchers at the University of California, Santa Barbara, have produced an insulin-loaded strip which would be transported through the body within a protecting polymer shell. By putting the patch incorporating insulin and an intestinal wall-permeation enhancer inside a stomach acid-resistant coated pill, the scientists developed a tablet that dissolves once in the right location within the intestinal tract allowing the insulin strip to affix itself to the intestinal wall prior to delivering the drug. The scientists experimented with rat and swine intestinal tracts to analyse both the ‘sticking’ power of the strip and the efficiency of delivery of its contents, with the most optimal concentrations of the permeation enhancer and drug combination able to trigger blood glucose levels to drop to about 70 percent of normal levels. If human trials of the insulin strip prove as effective, it will be very good news indeed for diabetes-suffers everywhere.
A scientific team at Carnegie Mellon University has just unveiled a 3D-bioprinting set-up that can be employed to generate soft interior body organs. Up until now, 3D-bioprinting has, for the most part, involved using components that supply their own structural support through their own intrinsic rigidity, for example, replacement bone structures that are made out of titanium. But when dealing with trying to replicate soft organs in the body, a structural problem arises during printing in that subsequent layers do not have the required underpinning support from previous layers. The Carnegie Mellon University group led by Adam Feinberg have shown that bioprinting of soft tissues like hearts can be done using a method referred to as Freeform Reversible Embedding of Suspended Hydrogels or FRESH. The technique, involves printing the gel that will make the walls of the soft tissue completely within the confines of a second supporting gel allowing the soft-tissue organ to be synthesised. As with other bioprinters, the teams’s new 3D-bioprinter precisely injects layers of a tissue-building gel inside the supporting one to create the required shape. Then, much like quick-dissolving support filaments that are used to support gravity-defying structures within other 3D-printed designs, the support gel can be dissolved in 37C water, leaving behind the bioprinted organ ready for implantation into the patient. Donor organ transplants could very well soon be a distant memory.