Activity 1 The following is a headline from ABC news online, August 13 2008: ‘ A 14 year-old boy has died from a suspected case of meningococcal disease on the New South Wales central coast .’ Perform the Meningitis Activity to learn more about this fatal disease.
The bacteria grow in the cells lining the nose and throat - spread by contact eg sneezing, kissing, sharing drinks
The bacteria produce a toxin which causes fever, damage to blood vessels, tissue damage and blood clots
It is fatal in about 10% of cases but 10-15% of people who survive the disease have ongoing health problems - eg deafness, loss of limbs, paralysis, brain damage
Early diagnosis and treatment is critical to improve outcomes.
Two Types Of Meningococcal Disease
Meningitis - bacteria attack the meninges (lining around the brain) - early symptom is a stiff, sore neck - meninges and brain swell, putting pressure on nerves - survivors often left deaf or with brain damage
Sepsis - infection occurs throughout the bloodstream - affects the entire body - bacterial toxins rupture blood vessels and can rapidly shut down vital organs - survivors often left with permanent injuries and/or require amputations.
As the bacteria multiply and move through the bloodstream, they shed bubbles that contain concentrated amounts of toxin. These bubbles also act as decoys, confusing the body's immune system
The endotoxin targets the heart, affecting its ability to pump and also causes blood vessels throughout the body to leak. As every vessel starts to haemorrhage, major organs like the lungs and kidneys are damaged and eventually destroyed
Two things can stop this runaway infection before the patient dies: antibiotics like penicillin, and the patient's own immune system .
Not All Bacteria Is Bad Image: Yakult.Honsah@wikipedia
Very few bacteria are harmful, most bacteria have the following functions: - Food production - Normally live on our bodies and stop pathogenic bacteria from growing - Help with digestion (hence dietary supplements) - Can be genetically altered to make the products we need in the laboratory e.g. vaccines, drugs.
Experiment 1 Observation Of Bacteria Perform the Observation of Bacteria experiment as instructed by your teacher.
How Can We Diagnose Meningitis?
Current tests detect bacterial proteins in blood/other fluid - can only detect in the range of micro) mol (10 -6 ) to pico mol (10 -12 ) of protein concentration
If we develop new tests using gold nanoparticles combined with DNA amplification we could detect molecule concentrations in the atto (10 -18 ) mol range i.e. one million times more sensitive than current tests
This would allow earlier detection and therefore faster medical interventions.
What Are Gold Nanoparticles? Image: Northwestern University
Gold nanoparticles (‘ nanogold ’) occur as clusters of gold atoms up to 100nm in diameter.
Nanogold has unusual visible properties because the particles are small enough to scatter visible light - in contrast, mass gold reflects light
Gold nanoparticles appear deep red to black in solution - colour depends on size of nanoparticles
The distance between particles also affects colour - surface plasmon resonance is the term used by nanotechnologists to describe this effect.
5nm gold clusters Gold nanoparticle
Experiment 2 Making Gold Nanoparticles Perform or watch a demonstration of the Making Gold Nanoparticles Experiment to see the differing chromic properties of nanoparticulate gold for yourself.
Animation
View the Nanoparticles Diagnostics Animation to better understand how gold nanoparticles are used to detect bacterial meningitis
Complete a flow chart outlining the key steps in the nanoparticle diagnostic test.
Activity 2
Use the Nick’s Test PowerPoint presentation provided by your teacher to model the use of a nanoparticle diagnostic test in real-life
Answer the questions on the last slide.
Rapid Diagnosis So nanogold can be used to rapidly diagnose meningitis… … what else can nanogold offer to the world of medicine?
Imagine if your tumour grew in an important part of the brain. Surgery could save your life but you would end up permanently and severely disabled.
Now, imagine if there was an alternative…
Nanogold: ‘Nanobullets’ To Treat Cancer Image: iurifernandes@flickr
Also called 'thermal scalpels‘ or ‘nano bullets’
Particularly useful for small cancers that are embedded in vital tissues such as the brain
The nanoshells are silica coated with gold nanoparticles that binds them to cancer cells, and are then injected into tumours
Light from a near-infrared laser, which is harmless to healthy tissue, is absorbed by the nanoshells. The nanoshells heat up, destroying the tumour cells.
Nanogold: ‘Drug Smugglers’ To Treat Cancer Image: Courtesy E. Zubarev, Rice University
Gold Nanoparticles coated with bristles of an anticancer drug, Taxol®
Travel inside cancer cells and bind to internal structures
Activity 3 & Experiment 3 Perform the Gold Nanobullets Activity and the Golden Cancer Treatment Experiment to better understand the benefits of using nanogold to treat cancer .
Australian scientists at Ambri Ltd (Sydney) have used nanotechnology to developed a rapid, single-use diagnostic test to detect bacteria in samples-could test biological fluids, food, water.
What If? What if you could detect disease at home with a ‘lab on a chip’?
Nanoparticles are bound to antibodies that recognise a disease marker protein – a protein found only in a disease state, or at higher levels in a disease state
When the protein is present in a sample, extraction of the magnetic particles also pulls out the gold nanoparticles because the two are bound together
The DNA on the gold nanoparticle can be copied many times, so very small amounts of the original protein can be detected
Potentially, nanoparticles with different antibody and DNA fragment combinations could be used to search for multiple disease marker proteins at the one time (hence the 'biobarcode').
View the BioBarcode Animation
What If? What if you could rapidly sequence DNA on a space mission? NASA is working on a ‘Nanopore Sensor’ to rapidly sequence DNA - detect DNA of pathogenic bacteria or viruses in astronauts - sequence DNA of new life forms. Image: mujitra@flickr
Biocompatible and non-toxic - useful for sensitive organs like the kidney - highly valuable for people who are allergic to dyes.
Gold nanoparticles highlight the cancer in mouse leg (arrow) compared to the other healthy leg.
Nano-Imaging In Australia
Nanotechnology Victoria and RMIT Medical Radiations have a collaboration investigating the use of nanogold for combined X-Ray imaging and radiotherapy, with a focus on cancer detection and treatment.
ureter Dr Jeanette Pritchard, Manager, Imaging Delivery & Sensing, Nanotechnology Victoria Ltd
Animation ureter View the Nano-imaging Animation .
Now Let’s Get Really Imaginative…. ureter
What If? ureter
A ‘nanobot’ is a robot constructed from nanoscale components
Nanobots could one day be injected into the body to treat diseases by delivering drugs or to perform surgery
Nanobots could also perform a surveillance function where they check that the body is healthy and detect diseases very early.
Researchers led by Dr James Friend at the MicroNanoPhysics Research Laboratory at Monash University, Melbourne are developing robot-like components and motors at the micro- and nano-scales.
Watch the Micro-motor Animation to learn more
ureter
Activity 4 Perform the Nanobots and Design Your Own Nanobot activities to explore this concept further.
Quantum Problems ureter
Play Duckboy in Nanoland! www. sciencemuseum .org. uk /antenna/ nano / nanoland / nanoworld .asp
MURKY MANSION
STUCK WITH THE DUCK
STRANGE ATTRACTIONS
BROWNIAN BUMPERS
FUNHOUSE
Answer the questions in the Design Your Own Nanobot Activity which relate to this game.
Summary ureter
Meningococcal meningitis is a deadly bacterial disease for which rapid diagnosis can be critical to prevent death and permanent side effects
Gold nanoparticles have been used by Australian scientists to develop a rapid and sensitive test for meningococcal meningitis
Gold nanoparticles are the focus of many health tools currently in development - targeted at prevention, diagnosis and treatment.
Revision
What is bacterial meningitis and how do the bacteria cause the symptoms of the disease?
Why have scientists developed a rapid diagnostic test for meningococcal infection?
Describe one way that gold nanoparticles can be used to treat cancer.
Do you believe that nanobots will one day be a reality? What problems must nanobot designers overcome?
0 comments
Post a comment