Exam Questions and CORRECT Answers
difference between nano devices and nanoparticles - CORRECT ANSWER - - nano
devices: they are made of nanoparticles (usually with different composition -- ex. microneedles
and nano needles, and nano-valves for drug delivery)
- nanoparticles: particle of any shape with dimensions in the 1 x 10 ^-9 - 1x10 ^-7 (1-100nm)
why did we study micro-needles if they are not a nano object? - CORRECT ANSWER -
because they are still relevant in the field of medicine. Microneedles permit transport of
macromolecules, as well as possibly supramolecular complexes and Microparticles
which skin layer can be reached using micro-needles? - CORRECT ANSWER - stratum
corneum
describe the three transdermal drug delivery methods using micro-needles - CORRECT
ANSWER - 1. poke with a patch -- use for insulin delivery into diabetic hairless rats (sol
of insulin was placed on top of the micro needle array and left)
2. coat and poke -- used for protein vaccine delivery (microneedles prepared with dry film
coating of antigen and then inserted into skin of hairless guinea pig -- possible allergy
treatment?)
3. dip and scrape -- used for DNA delivery (arrays dipped into a solution of DNA and scraped
multiple times across the skin of mice to create micro abrasions)
which skin layer can be reached using nano-needles? - CORRECT ANSWER - can only
reach the upper layer of the epidermis because they are too small to penetrate the stratum
corneum
what are the main applications of nano-needles - CORRECT ANSWER - drug delivery
without nanoparticles and manipulation of organelles
, describe and understand how it works the nano-valve designed by Zink et al - CORRECT
ANSWER - - a nano-valve that can be opened and closed (trap and release molecules0 --
could be used for drug delivery such as insulin release
how it works:
1. guest molecule is loaded into the pores (by diffusion)
2. valve is closed bc of oxidation of TTF
3. valve is opened by adding ascorbic acid to reduce TTF (position of CBPQT4 ring changes)
4. release of the guest molecule
what is nano-endoscopy as defined by Zhang et al - CORRECT ANSWER - - single cell
endoscopy: probes accurately inserted into a live cell (allows for intracellular analysis)
- Zhang et al fabricated a nano device -- assembled single nanoporus gold nanowire on the tip of
a tungsten needle (+ NP to sense different cell types)
- sensing biomarkers for disease and able to eliminate damaged cells at an early state
what are the advantages of performing nano coating on surgical blades? - CORRECT
ANSWER - - performance of surgical blade can be enhanced with NP coating (when hard
metal is coated with diamond -- micro or nano structures)
- will allow cutting edge diameter in nano surgery
- diamond also has a low friction coefficient (decrease the penetration force needed)
what has been the main application of nanotechnology in orthopedics? - CORRECT
ANSWER - - nanocoating implant surfaces (can increase biocompatibility)
- ex. HRN (helical rosette nanotubes) are self-assembled organic nanotubes possessing
biologically-inspired nanoscale dimensions