Oncology Flashcards
What is cancer? (2 points)
- disease characterised by uncontrolled, unregulated growth of abnormal forms of the body’s own cells.
- these cells invade surrounding tissues and migrate to other parts of the body
What are the 4 main characteristics of cancer cells that distinguish them from normal cells?
- uncontrolled growth
- loss of function
- invasiveness
- metastases
What are the 4 main types of tumour types?
- carcinoma (skin or tissues lining organs)
- sarcoma (bone, muscle, blood vessels, tissues)
- leukaemia (bone marrow)
- Lymphoma (immune system)
What are the 5 approaches in cancer treatment?
- chemotherapy
- surgery
- radiotherapy
- hormone therapy
- immune therapy
What is the purpose of chemo and radiation?
-to kill tumour cells as these cells are more susceptible to the actions of these drugs
What are the problems associated with chemotherapy? (6 points)
Side effects which arise from parameters such as
- formulation factors (solubilisers)
- PK variability
- non-selective toxicity
- poor drug solubility and stability
- drug resistance
- lack of oral chemotherapy
What are the attempts of newer chemotherapy formulations focussing on? (2 points)
- efforts to kill cancer cells by more specific targeting while sparing normal cells
- to achieve this, the focus is on development of novel drug delivery carriers for both existing and new drugs
What are the roles of drug delivery systems (4 points)
- reduced side effect of chemo agents
- enabling new and better chemotherapeutics regimen using existing pharmaceuticals
- facilitate cancer prevention
- pain management assoc with caner progression and chemo
What are the different drug delivery strategies? (8 points)
- chemotherapy wafers
- patches
- osmotic pumps
- PEGylated liposomes
- liposomes
- microspheres
- polymer-drug conjugates
- microchips
What are nanoparticulate drug delivery carriers? (2 points)
- NPs are engineered, constructed systems measured in nm size.
- made of polymers/polysaccharides of different nature
What are the advantages of NP carrier systems to tumour tissues? (3 points)
-enhanced permeation through tumour due to leaky, abnormal vasculature of cancer site (small particle size
What are the limitations of NP delivery?
-NPs will be taken up by liver, spleen and other parts of the reticulo-endothelium system, depending on their surface characteristics and particle size
What are the two ways of targeting NP to tumour tissues?
- passive targeting
- active targeting
What is passive targeting? (2 points)
- limited to RES uptake after injection of NP
- this limits the effective delivery of anticancer drug-loaded NPs to cancer cells
What is active targeting?
-this involves drug delivery to a specific site based on molecular recognition
What are the 5 strategies to improve active targeting to avoid RES?
- PEGylation
- construction of particles with hydrophilic surface
- couple a ligand to the NP
- use magnetic field
- size reduction
How does PEGylation improve active targeting?
-adds polyethylene glycol over surface of NP so it is not recognised by the RES
How does a hydrophlic surface help improve active targeting to avoid RES? (2 points)
- hydrophilic surface either by construction or coating with surfactant creates cloud of chains at the particle surface
- this repels plasma proteins and prevents opsonisation [cloud effect]
How does coupling a ligand to a NP improve active targeting to avoid RES?
- the ligand can interact with its receptor at the target cell site
- e.g. binding of folate to pyglayted particles for interaction with folate receptor
How does magnetic field help to improve active targeting to avoid RES?
-Magnetic field can be used to orient the NP towards a magnetic field created at the tumour site
What are the 5 types of nanoparticles?
- dendrimers
- nanospheres
- nanocapsules
- fullerenes and nanotubes
- liposomes
What are dendrimers?
-regularly branched 3D tree like structures with multifunctional central core
What are nanospheres?
-spherical structures composed of matrix system where drug is distributed by entrapment, attachment or encapsulation
What are nanocapsules?
-vesicular systems with central cavity/core
which is surrounded by an outer shell polymeric membrane
