At the start of the 21st century, alternatives to animal use, referred to as Replacement Science, have become the cutting edge of medical research. Animal experiments are being replaced by a range of alternative (non-animal) methods that have proven cheaper, quicker and more effective.
Human cells and tissues are obtained from biopsies, post-mortems, placentas, or as waste from surgery, and can be grown in the laboratory. Cell cultures, both 2D and 3D, are used in many medical fields, and have contributed to our understanding of the underlying mechanisms of diseases and disorders such as cancer, Parkinson's disease and AIDS. Cell cultures are routinely used in vaccine production, toxicity testing, drug development and for diagnosis.
It is important that human cells, rather than animal cells, are used for medical research, to avoid the problems inherent in extrapolating results from one species to another. To encourage the use of human tissue the Dr Hadwen Trust for Humane Research (DHT) has helped establish human tissue banks and has also funded research using human cells and tissues to replace animal experiments in the most diverse areas of medical research including neurological disorders, respiratory diseases, infectious diseases and genetic diseases.
Technological advances are resulting in new and improved molecular methods for analysing and identifying new compounds and medicines. The Dr Hadwen Trust has provided analytical equipment to researchers selecting new anti-cancer and anti-malaria drugs, based on their molecular interaction with DNA.
Research at the molecular level is being used to understand the biochemistry and genetics underlying various illnesses, to develop better treatments. DHT-funded projects have used gene microarray technology to identify changing gene activity in cells from patients with chronic leg ulcers. These types of approaches will help explain why wounds fail to heal, and could replace painful experiments on animals such as rabbits, pigs and hamsters.
Tests with simple micro-organisms, such as bacteria and yeast, are being used as early indicators of chemicals likely to be harmful to humans, and are faster, cheaper and more humane than animal tests. Bacteria can be genetically manipulated to produce recombinant proteins previously obtained from animals, such as human insulin and monoclonal antibodies.
DHT-funded research into diabetes successfully used a microscopic organism called Hydra, as an alternative to animals with artificially induced diabetes. Another DHT-funded researcher has developed an in vitro method of growing the microbes responsible for causing sleeping sickness, a fatal tropical illness, which replaces the mice normally used for research into this disease.
Computers are increasingly being used to model the structure and actions of new drugs, and to predict their safety. Computer models of whole biological systems are now being developed on which 'virtual' experiments can be conducted.
DHT- funded research on various computer models include a model of the human placenta and foetus to study problems affecting unborn babies; and a model of the human jaw and teeth for dental research. These models are based on relevant human data and can be used to carry out simulated experiments. The DHT has also supported work using mathematical modelling to improve cancer treatments, and to explore illnesses of ageing.
Population Studies - Epidemiology
Studying diseases in human populations, and the effects of lifestyle, genes, diet and occupation, has already revealed a great deal about cancer, heart disease, osteoporosis and birth defects. Such information is vital to improving human health and providing clues to the causes of illnesses. The DHT has funded a population study-based project into how foetal and infant growth influences the development of heart disease in later life, to replace experiments on pregnant animals.
One of the best ways to conduct medical research is by studying human volunteers. New analysis and statistical techniques are making it increasingly possible to conduct safe and ethical studies of human volunteers, where previously animals had been used.
DHT-funded projects use a variety of sophisticated imaging techniques to non-invasively investigate the intact human body. These include using a MEG (magnetoencephalography) scanner to study epileptic patients and drug effects on the brain; investigating pain in patients using fMRI (Fourier Magnetic Resonance Imaging); developing a novel technique, TMS (Trans-cranial Magnetic Stimulation), to study the function of the human brain in healthy volunteers; and understanding human brain circuitry using a new approach called diffusion tensor imaging (dtMRI).