Introduction to Pharmacology and Toxicology- Biopharmaceuticals and gene therapy

Question 1

What is a biological product?

Answer 1

• Includes proteins, antibodies and oligonucleotides and their use as drugs
• Use of nature to be used as therapeutic purposes
• Product on the market in the laboratory or going through clinical trials
• First and second generation biopharmaceuticals

Question 2

What are first generation biopharmaceuticals?

Answer 2

Mainly copies of endogenous proteins or antibodies produced by recombinant DNA technology

Question 3

What are second generation biopharmaceuticals?

Answer 3

Engineered to improve the performance of the protein or antibody

Question 4

What is Recombinant DNA technology?

Answer 4

1. The plasmid is inserted contains cDNA version of mRNA required for protein of interest
2. Inserted into the bacteria
3. Slow production of protein is formed

Question 5

How are biopharmaceuticals designed and used? What is specifically looked at?

Answer 5

1. Potency
2. Specificity
3. Side effects
   These are all the intrinsic properties that you need to target the receptors and transporters you’re interested in
4. Delivery- get the intrinsic properties in to have an effect
   - Can’t be delivered orally (especially peptide/protein)- as the enzymes in stomach will break it down- poor bioavailability
5. Can’t/difficult to cross the blood brain barrier- size may be too big- may require surgery
6. Broken down by ubiquitous proteases- injected rapidly to be metabolised

Question 6

What are the outside considerations you have to take into account for the production of biopharmaceuticals?

Answer 6

1. Manufacture
   - Cost more to make than organic chemicals
   - Yields may be low
   - Purification- cows secrete protein into the milk
   - Quality control- pure product and not contaminated with anything that isn’t a therapeutic benefit
2. Stability
   - Proteins often unstable= sensitive to heat and light etc- think about formulation and how to overcome these
   - Storage and shelf life is an issue

Question 7

What are the different routes of administration for the different forms of insulins?

Answer 7

1. Pulmonary delivery (aerosol, dry powder)- inhalation- inhaler
2. Transdermal delivery (patches, creams and sprays)- across the skin- hydrophilic

Question 8

What are the main intracellular targets for biopharmaceuticals?

Answer 8

1. Mitochondrial/sub cellular targets- Lyosomal enzymes
2. Nuclear targets- DNA and RNA binding proteins
3. Cytoplasmic targets- kinases
4. Intracellular pathogens- inhibitors or promoters of fusion

Question 9

What are the Therapeutic Proteins?

Answer 9

1. Peptide hormones- insulin, something to replace something missing which causes it to become dysfunctional
2. Therapeutic enzymes
3. Anti-bodies
4. Extracted from natural sources
   - Pigs (insulins)
   - Human Cadavers (growth hormone)
5. Recombinant DNA technology- insulin

Question 10

What are the three examples of proteins that are used to replace a missing factor?

Answer 10

1. Insulin (hormone)- replaces insulin in type I diabetics who have reduced ability to produce insulin
2. Somatotropin (Hormone)- Growth hormone to prevent reduced stature- retarded growth
3. Factor VIII (8) (Coagulation Factor)- For haemophilia replaces a missing clotting factor in the blood

Question 11

What is the insulin used for, its mechanism of action, how is it administered and what are the types?

Answer 11

Indication: Type I diabetes mellitus

Mechanism of action: Insulin receptor agonist

Administration: Subcutaneous injections (pen devices)

Types: Short acting and long acting- long acting is used to increase half life.

Question 12

How is insulin produced via recombinant DNA?

Answer 12

1. Human pancreas cell has its insulin DNA producing gene cut out
2. This is implemented into plasmid DNA that’s cut with restriction enzymes
3. A recombinant DNA is created and implemented into a bacterium thats put into a fermentation tank
4. Multiplying and producing human insulin- extraction and purification

Question 13

What stimulates the production of red blood cells in treatment of chronic renal failure and anaemia in association with EPI deficiency?

Answer 13

Erthropoetin

Question 14

What factor helps promote wound healing?

Answer 14

Platelet derived growth factor

Question 15

What influences orthopaedic surgery, bone repair and promotes vertebral fusion?

Answer 15

Bone Morphogenic proteins

Question 16

What factor influences hepatitis and multiple sclerosis?

Answer 16

Interferons

Question 17

What is the role of tPA?

Answer 17

1. Turns plasminogen (inactive) to plasmin (active)

2. This encourages the Thrombus (blood clot) to turn into a proteolytic degradation product

Question 18

What are monoclonal antibodies?

Answer 18

1. Very specific antagonists
Y proteins
- bind to natural ligand- high degree of specificity
- neutralise effect
- may contain part of receptor

2. Humanised antibodies
   - Overcome immune response
3. Disease modifying agents

Example: Infliximab- treatment of Crohn’s disease

Question 19

What are nano bodies?

Answer 19

Anti-bodies that are much smaller in terms of size and can be used for difficult target- this may be drugs for different anti-bodies and individual ion channels.

Question 20

What is gene therapy?

Answer 20

1. The replacement of a defective gene with a normal healthy gene itself
2. The genetic modification of cells to prevent, alleviate or cure disease

Question 21

What are some examples of uses of gene therapy?

Answer 21

1. The curing of monogenic diseases such as cystic fibrosis

2. Curing of neurodegenerative diseases and infectious diseases