Research Roundup: novel male contraceptive shown to be effective in rats; how pufferfish biology is inspiring bio-engineering of pills and more!

Welcome to this week’s Research Roundup. These Friday posts aim to inform our readers about the many stories that relate to animal research each week. Do you have an animal research story we should include in next week’s Research Roundup? You can send it to us via our Facebook page or through the contact form on the website.

  • New male contraceptive effective on rats. Researchers from Nanchang University, in China, have developed a new male contraceptive by injecting four layers of materials into the vas deferens — the tube that sperm passes through. The layers are injected in a specific order; first calcium alginate hydrogel, then gold nanoparticles, then ethylenediaminetetraacetic acid (EDTA), and another layer of gold particles. They hydrogel provides a physical barrier to prevent sperm from leaving during ejaculation, and the EDTA kills sperm as a secondary contraceptive. Both layers of gold nanoparticles hold the other materials in place and help release the layers when the contraceptive is no longer wanted. Specifically, doctors can apply near-infrared light to heat up the gold, which causes the layers to mix; breaking down the hydrogel for easy flushing by the patient. The treatment was effective on male rats, and was tested for two months. It is unclear if this method will come to humans because other methods like Vasalgel, ultrasound pulses, contraceptive pills, and topical gels are further along in preclinical and clinical trials. Published in ACS Nano.
  • Pufferfish biology inspires pill to monitor gastric health. MIT scientists have copied the ability of pufferfish, to suck in water and expand their body to twice its normal size, for a new ingestible pill that lives in the stomach to track pH levels and observe tumors and ulcers. Several ingestible pills have already been developed, but they pass through the digestive tract, leaving the body. Using the pufferfish technology, the pill can be ingested and expands itself by sucking in the stomach acids. The swollen pill can be removed by drinking calcium ions that force the pill to shrink back down in size and exit the body through the intestines. The pill was successfully tested on pigs for 30 days. Published in Nature Communications.
A series of images showing a pill prior to hydration (left), a swollen pill (middle), and pill that has been shrunk (right) (Credit: Xinyue Liu, Shaoting Lin)
  • Why the extinction of lemurs has major implications for scientists. Nearly all lemurs live on the island of Madagascar–and they are on the verge of extinction. In addition to this crisis, Dr. Patricia Wright, of Stony Brook University in New York, writes, “A lot of the experiments on human health are done on the mouse and the mouse is not related to us and it only lives two years so you couldn’t possibly study some of the long-term kind of diseases.” As an example, of what Wright means, she has imbedded computer chips in lemurs in the wild in an effort to monitor the development of Alzheimer’s disease–for as long as 20 years. In addition, and in contrast to other models of Alzheimer’s, lemurs actually develop amyloid beta plaques naturally with age. Lemur’s are on the verge of extinction because of the decimation of their natural habitat–and currently the only ½ of all baby lemurs survive to adulthood. Now, more than ever, is the time to act.
Dr. Patricia Wright of Stony Brook University studies a ring-tailed lemur in the wild. Source; CBS News
  • How whipworms wreak havoc on the gut. The human gut is home to millions of bacteria, collectively called the microbiota, and also to parasites such as whipworms, which cause a human disease called trichuriasis. Cells lining the gut host whipworms but also interact with gut immune cells to deploy measures that control or expel whipworms while maintaining a barrier to prevent microbial movement to organs such as the liver. Whipworms affect the composition of the microbiota, which in turn impacts the condition of the gut lining and the way in which immune cells are activated. In order to avoid tissue damage and disease, these interactions are tightly regulated. Using a mouse model, Duque-Correa and colleagues show that these interactions are regulated by signaling through a member of the IL-10 receptor family, IL-10Rα, on gut immune cells. Published in PLOS Pathogens.