Basics of Gene Delivery (D5) Flashcards
Das lecture 5 of 5
What is gene therapy?
- A method of treating disease through the modification of a patients genome toward a therapeutic goal
How does gene therapy work (briefly?
- Genetic material is transferred via carriers to to target cells carrying damaged or abnormal genes, leading either to genetic correction or cell death
What is meant by indirect and direct gene therapy?
Indirect (In-vitro)
- a sample of cells are taken and cultured in a lab, these cells are injected with a virus or non-viral carrier carrying the desired DNA/RNA. The cells are genetically modified to express this new gene and then injected into the patient
Direct (in-vivo)
- A viral or non-viral carrier of the DNA/RNA is injected into the patient directly where it modifies the cellular genome in-vivo.
What 2 types of carriers are used in gene therapy?
Viral and non-viral
What kinds of virus carriers are there?
- Adenovirus, lentivirus, retrovirus, adeno-associated virus
Give an example of some non-viral carriers used in gene therapy?
Plasmids
Liposomes
What is a monogenic disease?
A disease that is caused by the disorder of a single gene
What kinds of diseases have been addressed through gene therapy approaches?
Monogenic diseases such as:
- Cystic fibrosis
- Haemophilia
Cancers and tumours
How can liposomes be modified to improved transfer of nucleic acid into target cells?
- Coat the liposome in drug or proteins to evade breakdown or target specific cells
What is a biological ballistic system?
It is a system of firing particles at high velocity to penetrate and introduce material into biological tissues
What 3 biological ballistic systems are there>
1) Gunpowder driven
2) Electric discharge
3) Gas power by compression of helium
What are the principle stages in the process of ballistic firing of particles?
(3)
1) Fire the particles at high velocity (acceleration stage)
2) The large lumps of particles are broken down into smaller lumps as they pass through a mesh (Separation stage)
3) The particles hit the target cells and decelerate (deceleration stage)
What is the major disadvantage to using gene guns?
- Cell damage from pressurized gas and micro-particle collision
What are these?
Explain how a powder gene gun works
Genetic material, often in the form of microparticles coated with DNA or RNA, is loaded onto small carrier particles.
Instead of using compressed gas, a propellant in powder form is incorporated into the gene gun device.
Ignition of the powder propellant results in rapid combustion, generating high-pressure gases.
The high-pressure gases accelerate the coated particles, leading to their expulsion from the gene gun.
The accelerated particles impact the target cells, facilitating the penetration of genetic material into the cells.
The introduced genetic material can integrate into the cellular machinery, resulting in genetic transformation.
Explain how a gas gene gun works
Genetic material, often in the form of DNA-coated particles, is loaded onto small carrier particles.
The gene gun chamber is pressurized with a gas, commonly helium.
The pressurized gas is rapidly released, propelling the coated microprojectiles at high velocities.
The accelerated microprojectiles impact the target cells, facilitating the penetration of genetic material into the cells.
The introduced genetic material can integrate into the cellular machinery, resulting in genetic transformation.
