Biological Medicine By Benji Marks

What is it? Biological drugs: substance made from a living organism (or its products) and is used for treatment and prevention of cancer (and other diseases) (Anything that is naturally made and can fight off infection) Examples are: vaccines, antibodies, interleukins (immune system) NEXT: Examples/developments

Bacteriophages Alternative to antibiotics (antibiotic resistance) Uses viruses to kill bacteria (interesting!!) Discovered in 1917, but was eclipsed by the discovery of penicillin How they work: Phage lands on bacteria cell Injects its DNA into the bacteria DNA is copied and used for packaging to make a new generation of phages New phages assemble and release toxins to kill bacteria cell and spread

Advantages of Bacteriophages Specific to one species of bacteria, so do not disturb any beneficial bacterial cells Destroy the bacterial cell wall and cell membrane= harder for bacteria to develop to resistance as cell is killed Digests biofilm (thick layer that bacteria make to protect them from antibiotics) No major safety concerns if done properly (research suggests)

Why are phages not used? More difficult to prepare cleanly: large quantity of bacteria have to be grown and non-removal of dead bacteria cell= sepsis Hard to judge the concentration needed: low conc.= ineffective Many early trials of phage therapy were of poor quality= discredited Longer time to employ in treatment (compared to antibiotics): searching for correct phage takes time, which isn’t ideal if patient is very ill Not a lot of data: phage therapy was abandoned decades ago, but lots of research is happening (in France and Georgia particularly)

Stem Cell Treatment Undifferentiated cells which can become specialised to suit a particular purpose (e.g: blood cells, brain cells, heart muscle cells) Extracted from either bone marrow (more popular) or embryos Used to treat: leukaemia, severe aplastic anaemia, sickle cell anaemia Procedure: Extraction of stem cells Conditioning of body for treatment (chemotherapy) Transplanting stem cells (injection) Recovery in hospital for 8-12 weeks (usually)

Risks Graft versus Host Disease (GvHD)- transplanted cells can recognise recipient’s cells as ‘foreign’ and attack them Symptoms: rash, diarrhoea, nausea, joint pain, breath shortness Reduced number of blood cells- blood cells damaged during chemotherapy, could be harmful until replaced after a few weeks Can lead to: anaemia, excessive bleeding/bruising, infections Chemotherapy side effects: nausea, diarrhoea, loss of appetite, tiredness, hair loss (all temporary) High dose: permanent infertility

Benefits Recently shown to be able to treat Alzheimer’s, Parkinson’s, Stroke as new brain cells can be made from stem cells Can treat MS- research starting from March 2018 showed a 6% failure in stem cell treatment as opposed to 60% failure in drug treatments (Dr. Richard Burt) Can treat a variety of diseases Relatively new discovery: advancements can only increase from here. Hope is for stem cells to be a “renewable source of replacement cells and tissues” in the future

References http://sitn.hms.harvard.edu/flash/2018/bacteriophage-solution- antibiotics-problem/ https://www.mayoclinic.org/tests-procedures/bone-marrow- transplant/in-depth/stem-cells/art-20048117 https://www.nhs.uk/conditions/stem-cell-transplant/ https://draxe.com/stem-cell-therapy/