nanomedicine 1, 2 Flashcards
what is nanotechnology
study of things that when reduced in size they display unique different physiochemical properties than when compared to bulk material
or
creation of useful/functional devices or material through control/manipulation of matter on nanometre length scale
what is nanomedicine
use of nanotechnology to treat disease
ways nanoparticles treat cancer
lipid based nanocarriers- high degree of biocompatibility, encapsulates wide range
polymer based nanocarriers- suitable for development due to ease and adaptability, eg. polymeric NP, dendrimers, polymer micelles
inorganic nanoparticles- diagnosis/treatment due to superior physiochemical properties like magnetic, thermal, optical, catalytic, excellent functions like imaging, targeted delivery and controlled release
viral nanoparticles-plant virus nanoparticles can be functionalised to be taken up by cancer cells
drug conjugates- class of biopharmaceutical drugs designed to enhance efficacy of therapeutic targeting by allowing for targeting enhanced dose delivery
name 6 nanoparticle types
liposomes, gold nanoparticles, carbon nanotubes, iron oxide nanoparticles, quantum dots, polymer micelles
describe the characteristics of liposomes
present high loading efficacy ensuring a high dose delivered, encapsulates drugs by protecting them and designed to release on a stimulus like pH or light
describe the characteristics of gold nanoparticles
display unique optical characteristics at nanoscale, due to interactions with light photons giving the nanoparticle different colours depending on size
describe the characteristics of carbon nanotubes
display unique electrical properties compared to bulk material of carbon which doesnt display it, used to conjugate with drugs so they release drug on electrical stimulation
describe the characteristics of iron oxide nanoparticles
superior magnetic and thermal characteristics at nanoscale, used to develop imaging and thermal stimulated killing of cancer cells
describe the characteristics of quantum dots/semi conducting crystals
develop theranostics due to their unique optical properties, when exposed to light a unique light is produced depending on their nanoscale size and material properties, results from an electron being excited and forming a valent bond to a conduction band, energy required to do this is called a band gap, band gap=distance between valence band of electrons and the conduction band, band gap is minimum energy required to excite and electron up to a state in the conduction band where it can participate in conduction
-when bandgap lies in visible spectrum, a change in bandgap with size means change in colour
describe the characteristics of polymer micelles
unique mechanical and chemical phenomena at nanoscale, used to develop advanced drug delivery systems eg. swelling causes release of an encapsulated drug
main aims of nanotechnology
-create new properties- to understand control and create nanostructures
-improve ability to image/measure/manipulate matter on nanoscale to exploit those properties and functions
-ability to integrate those properties and functions into systems spanning nano to macroscopic scales
benefits of nanotechnology based drug delivery systems
-improved drug absorption
-reduced side effects
-targeted drug delivery
-controlled drug release
-creates more efficient/targeted/controlled systems
limitations of current drug delivery systems
-low drug absorption
-quick metabolism and excretion
-side effects
name different physical and chemical properties depending on size
optical properties, band gap energy, melting point, specific heat capacity, surface reactivity
advantages of nanoscale devices in medicine
-devices smaller than 50nm can easily enter most cells
-devices smaller than 20nm can transit out of blood vessels
-devices are capable of holding thousands of small molecules like drugs and contrast agents
major areas of development of nanomedicine
-prevention and control
-early detection
-imaging diagnostics
-multifunctional therapeutics
chemotherapy non targeted delivery, what pathway is used, what is it formulated with
uses endogenous albumin pathways, formulated with albumin obviates the need for toxic solvents, increase drug delivery initiating albumin receptor mediated transcytosis
what is transcytosis
type of transcellular transport in which various macomolecules are transported across the interior of a cell
-macromolecules captured in vesicles on one side, drawn across cell and ejected onto the other side
challenges/problems with cancer therapeutics in nanomedicine
delivery-nanoparticles difficult to deliver to tumours in the body, can be intercepted by immune system or other organs
targeting-difficult to target to specific cancer cells, can be taken up by healthy cells
toxicity-toxic to healthy cells causes side effects
cost-expensive to produce, makes them inaccessible to some patients
regulatory hurdles-regulatory process still in development, difficult to get new products approved for clinical use
binding strategies(?)
hydrophobic/hydrophilic drug, PEG, transferrin, cell penetrating peptide, fibronectin (ligand for integrin receptor), folate, fibroblast growth factor, matrix metalloproteinase ligand, antibody, genetic material, antibody fragment
stimuli responsive delivery in chemotherapy-cancer characteristics can be taken advantage of when developing drug delivery systems eg:
- leaky vascular system- enhanced permeability and retention effect
- cell surface receptors/markers
- inside tumour differences eg. reduced pH compared to healthy tissues
what is ROS mediated killing stimulated by and what is ROS
stimulated by: light, radiation, electric fields
-causes mediated ROS production via nano particles
ROS=toxic to cells in high concentrations due to high reactivity
gene/RNA therapy
causes detrimental effects to cancer, eg. stops key protein from being synthesised
nanoparticle physical properties
size, geometry, surface charge, porosity, elasticity, surface hydrophobicity, roughness, curvature, electronic, magnetic, optical
nanoparticle structure/chemical composition
liposomes, polymeric NOs, micelles, dendrimers, protein NPs, viral NPs, exosomes, metal and metal derived NPs, carbon nanomaterials
nanoparticle targeting ligands
small molecules, antibodies and fragments aptamers and nucleic acids, proteins and peptides, sugars
problems with cancer therapeutics in standard delivery systems
limited targeting, biodegradation of drug, rapid drug clearance, low specificity
vectors in nanomedicine (1st 2nd 3rd gen)
1st generation=nanospheres and nanocapsules
2nd generation=nanoparticles coated with hydrophilic polymers (PEG)
3rd generation=biodegradable core and polymer coating with a membrane recognition ligand
why nanoparticle is good for cancer
delivers directly to tumour, protects drug from being degraded, enhances drug delivery into diseased tissue, controls cell uptake allowing oncologists more control on determining how effective treatment is, prevents drug from interacting with normal cells
things that trigger nanoparticles to destroy tumours from within
thermo, magnetic, pH, light, electrical
difference between active and passive targeting
active targeting receptor makes it selective
passive targeting- shape/charge/lipophilicity makes it more likely to pass membrane of diseased cell
types of nanotheranostics being developed
liposomes-spherical vesicles of lipid bilayer, delivers variety of drugs, imaging agents, heat
polymeric nanoparticles- made from synthetic polymers, delivers drugs, imaging agents, genes
gold nanoparticles- delivers drugs, imaging agents, heat
magnetic nanoparticles- delivers drugs, imaging agents, heat, used to guide nanoparticles to tumours using magnetic fields
