drug formualtuion

Question 1

what does hypoxia do

Answer 1

helps the tumour to grow and esacpe treatembts

Question 2

what are the advantages of liposomes

Answer 2

they are easy and cheap to produce

Question 3

what are the quailites of tumour vessles

Answer 3

• far apart
• serpertine formation
• variable blood flow

Question 4

what are the factors in the microenviroment that affect the drug uptake and effectiveness in tumours

Answer 4

• angiogensis
  -nutrients and oxygen uptake
  -heterogeneicity of tumours
  -cell prolifertaion rate
  -intersistail fluid poressure

Question 5

what factor is induced in low o2 levels

Answer 5

HIF-1, hypoxia inducible factor 1

Question 6

what are the levels of O2 in hypoxic tumours

Answer 6

around 0.3%

Question 7

what does hypoxa selecetd pressures increase

Answer 7

intrinsic resistance to antitumour immunity, or immunosupression and can increase therapuetic reistance

Question 8

what is shunting

Answer 8

the blocking of the atrial part of into the venous part of the blood system without feeding the tissue properluy

Question 9

what are the qualities of hypoxic cancer cells

Answer 9

• high HIF-1
  -increased genetic instabilty
  -influence ECM remodellinh
  -altered angiogensis
  -less suspectible to chemo and radiation

Question 10

what biological marker is red and what does it do

Answer 10

Pimondazole - exogenous hypoxia marker

Question 11

what biological marker is brown and what does it

Answer 11

BrdU- marker of DNA proliferation incorporates itslef into the DNA

Question 12

What biological marker is blue and what does it do

Answer 12

Hoechst - blood perfusion marker, diffuses out of blood cells

Question 13

how is HIF activated

Answer 13

through the stabilisation of the alpha subunit

Question 14

how does HIF normally work

Answer 14

HIFa-> proline hydrolysis -> VHL mediated degradation

Question 15

what is the startergy to expolit tumour hypoxia

Answer 15

exlpoit the reductuve enviorment by using drugs that are reduced to cytoxic speices in the hypoxic regions if tumours

Question 16

what are the three main classes of hypoxia drugs

Answer 16

quinone antiboitics
nitroaramtics
di-N-oxides

Question 17

what is an examamnple of a di-N-oxide drug and how dies it work

Answer 17

AQ4N
in healthy cells just stays in the cytoplasm and has a low tocixity
if hypoxic cells then AQ4N is taken up and converted to AQ4 which is highly toxic and has stroing binding to DNA

Question 18

what does the upregualtion of EMT do

Answer 18

allows the tumour cells to be more plastic

Question 19

how do you create hypoxic cells

Answer 19

leave them for 24-48 hrs in low o2 anymore and they will die

Question 20

what cell culture can be used to look at hypoxia gradiatnets

Answer 20

spheirical

Question 21

what do carbinaic anhydrases 9 and 12 do

Answer 21

upregulated by hypoxia
- involved in intracellular pH regualtion
-indirect cells extracellular acidification

Question 22

what were the disadvatges of small molecule inhibitors for carbonic anhydrases

Answer 22

• weren’t specific enough
• had off target affects

Question 23

what features do carbonic anhydrases inhibitors have

Answer 23

• zinc binding group- binds to the enzymatic domain
• tail creates more elctivity
• linker which spaces the zinc deep into the enzyamtic cleft

Question 24

what is an example of a carbonic anhydrase inhibitor and what is its disadvangte

Answer 24

s4 and the disadvatge is it has a low uptake into the cells

Question 25

how do you make CAi more affective for the isotopes

Answer 25

by changing the variable region

Question 26

what are exmaples of nanoaprticles

Answer 26

liposomes

Question 27

what are the advatges of liposomes

Answer 27

- increased stability via encapsulation - can trap lipophilic and hydrophilic drugs - less toxic to snesnitive tissues -increased effficacy and theraputic affect - have flexibilty to couple with site spefic ligands to achieve active binding - tehy are non toxic, biodegradeable, biocompatible and non immunogenic

Question 28

what are the disadvantages of liposomes

Answer 28

- cost - not all will be stable - short half life - somtimes lipids undergo oxidation or hydrolysis like reactions - leakage and fusion of encapsulated drug

Question 29

what are lipsomes made out of

Answer 29

cholestrol and phosphloplids

Question 30

what is pahse transition tempertaure

Answer 30

the temperature required to change from a ordered gel phase to the disordered cystatline phase

Question 31

what isthe major draw back from using liposomes more often

Answer 31

their instabilty

Question 32

what are the stabilty asepcts of liposomes

Answer 32

- polar head - chain length - cholsterol: phospho lipid ratio - PEGlated - fatty acid chains - degree of unsaturation

Question 33

what does fatty acid chains do to help stabilty of lipsomes

Answer 33

reduces compactness

Question 34

what does PEGlation do for liposome stabilty

Answer 34

stops recognition from the immune system

Question 35

how does the chol: phospho lipid ratio help liposome stabilty

Answer 35

higher chol to phoso stabilises

Question 36

how does the degree of saturation help with liposome stabilty

Answer 36

lipids with unsaturated acyls are suspectebible to degradation

Question 37

what is passive intergration of drug to liposome

Answer 37

drug and liposomes are mixed together to get passive intergration and then gel filtration to get rid of the unbound inhibitor

Question 38

how does the drug get intregrated into liposome with hydration

Answer 38

this is passive - test the levels of chol:phopho - mix them togetehr and let the solvent evaporate - then hydrate with buffer for intergration - extrude - filtration chromotograhy

Question 39

what size do you want the liposomes

Answer 39

between large unilamer vesicles and small unilamer

Question 40

what is extrusion

Answer 40

when the lipsome suspension is passed through a membrane filter with a defined pore size. mikes liposomes smaller and more uniform

Question 41

what extruder would you use in a lab

Answer 41

high pressure commerical extruder

Question 42

what is active loading of the drugs

Answer 42

- liposomes are added to citrate buffer - then Na2Co3 added and exchanged for the buffer this creates a proton gradinet - then drig is added and exchanged into the liposome

Question 43

what is the differnce between active and passive loading

Answer 43

passive laoding is during the fomration of the vesicle passive loading is for hydrophlic or lipophilic drugs active is a after the formation of the vesicle active is for weakly acidic or wekaly alkaline drugs

Question 44

what features are looked at with liposome characterissation

Answer 44

- size - surface charge - drug encapsulation percentage - phase transition tempreature - lipid phase transisiton

Question 45

how is the size of liposome measured

Answer 45

static and dynamic light scattering

Question 46

how is the drug encapsulation percentage measured

Answer 46

spectrophometry or flourecsnt spectroscopy

Question 47

how is the surface charge measured

Answer 47

photon correlalation spectrascopy

Question 48

how is phase transition tenmpreatyre measured

Answer 48

diiferential scanning calorimetry

Question 49

how is lipid pahse transiiton measured

Answer 49

x-ray diffraction

Question 50

factors affecting the passive uptake of liposmes

Answer 50

- vascualr permabilty - level of angiogensis - size of the nanoparticle - physsiochemical properties - intersistal fluid pressure - lymphatic drainage

Question 51

what does active uptake of nanoparticle increase

Answer 51

- accumulation - specificty - drug uptake

Question 52

waht drug is 10 fld higher conc in liposome

Answer 52

daunoXone -> daunorubicin

Question 53

what liposome incorporates doxicrubin

Answer 53

doxcil and myocet allows greater accumulationof doxirubicn with reduced cardiomyopathy

Question 54

what is an example of a fucntionaliseed nanoparticle

Answer 54

liposome with retinoic acid loaded in them there is a greater uptake