Question 1 Flashcards
[1] Basic understanding of surface characterisation techniques (in a vacuum or water). IKL] [[CAN BE MADE BETTER]]
Atomic Force Microscopy (AFM):
AFM is used in Dip-Pen Nanolithography to deposit molecules on surfaces, highlighting its precision in various environments, including vacuum and potentially controlled moisture environments.
Justification: This demonstrates AFM’s versatility in surface characterization, able to operate in both ambient and controlled environments to maintain the integrity of sensitive samples.
Environmental Conditions:
Techniques like Environmental Scanning Electron Microscopy (ESEM) are adapted for use in environments that aren’t vacuum-sealed, allowing for the characterization of hydrated or wet samples without extensive preparation.
Justification: Understanding how characterization techniques adapt to environmental conditions is crucial for selecting the right method based on sample nature and the desired resolution.
Surface Sensitivity and Chemical Analysis:
Methods like X-ray Photoelectron Spectroscopy (XPS) are used to analyze surface chemistry and composition, essential for detailed surface studies under specific environmental conditions such as vacuum.
Justification: XPS’s ability to provide detailed chemical composition makes it invaluable for studies where surface contamination or modification needs to be precisely controlled and analyzed.
Dynamic Surface Characterization:
Quartz Crystal Microbalance (QCM) techniques can monitor surface interactions in real-time, particularly useful in liquid environments for studying adsorption and other surface dynamics.
Justification: Real-time monitoring capabilities are essential for applications where surface interactions are dynamic and need to be understood in situ, such as in biological or aqueous environments.
[2] Basic understanding of induced pluripotent stem cells (iPSCs) [IKL]
Discovery and Basic Concept:
iPSCs are derived from adult cells that are reprogrammed to an embryonic stem cell-like state by introducing specific genes. This process is called cellular reprogramming.
Key Transcription Factors:
The transformation to iPSCs is achieved by inducing four key transcription factors: Oct4, Sox2, Klf4, and Myc.
Ethical Advantage:
iPSC technology provides a promising alternative to embryonic stem cells (ESCs) by avoiding ethical issues related to the use of human embryos in research.
Applications in Medicine:
iPSCs have significant therapeutic potential, notably in regenerative medicine, disease modeling, and drug testing.
Demonstration Across Cell Types:
The capability to reprogram various differentiated cells into iPSCs has been successfully demonstrated, not just with fibroblasts.
Justification: This flexibility in the source cell types for generating iPSCs is pivotal for tailored therapeutic applications and increases the scope of their use in genetic and cellular studies.
[3] Basic understanding of different types of bioreactors for tissue engineering [IKL]
Stirred-Tank Bioreactors:
Commonly used for the cultivation of cellular suspensions and microcarrier cultures. They are equipped with a mechanical agitator to ensure proper mixing and oxygen transfer.
Spinner Flask Bioreactors:
Similar to stirred-tank but typically used for smaller scale experiments. These bioreactors utilize a magnetic stirrer to facilitate cell growth on microcarriers or scaffolds.
Rotating Wall Bioreactors:
Designed to minimize shear stress by rotating the culture medium around a stationary central axis. Ideal for the growth of delicate tissues such as cardiac and neural tissues.
Perfusion Bioreactors:
Allow continuous media flow through the scaffold, providing fresh nutrients and removing waste to maintain cell viability. Effective for culturing high-density cell populations.
Fluidized Bed Bioreactors:
Employ a continuous flow of culture medium to keep cells in suspension, enabling efficient nutrient and gas exchange. Useful for bone and cartilage tissue engineering.
[4] Basic understanding of different cell sources for tissue engineering [IKL]
Autologous Cells:
Cells sourced from the patient’s own body, used to avoid immune rejection and ethical issues.
Allogeneic Cells:
Cells sourced from a donor, requiring immunosuppressive drugs to prevent rejection, similar to organ transplants.
Xenogenic Cells:
Cells sourced from a different species, which present significant ethical, biosafety, and immunological challenges.
Stem Cells:
Include a variety of sources such as embryonic stem cells, mesenchymal stem cells from adult sources (like bone marrow), and induced pluripotent stem cells. These cells can differentiate into multiple cell types and are considered ideal for regenerative purposes due to their versatility and potential for customization.
[5] Basic understanding of the role of the extracellular matrix (ECM) [AME]
Structural Support:
The ECM provides the necessary structural framework for tissue and organ formation, supporting cell adhesion and maintaining the physical properties of tissues.
Regulation of Cellular Functions:
It plays a crucial role in regulating cellular behaviors such as differentiation, migration, and proliferation, essential for tissue development and healing.
Biochemical Support:
The ECM is rich in growth factors and cytokines that regulate a wide range of cellular functions, including those critical for wound healing and tissue regeneration.
Dynamic Remodeling:
It is capable of dynamic remodeling, allowing tissues to respond to environmental changes and injuries, which is fundamental for tissue engineering applications.
Influence on Mechanical Properties:
The ECM affects the mechanical properties of tissues, such as stiffness and elasticity, which influence cell behavior and tissue function, crucial for designing scaffolds in tissue engineering.
[6] Basic knowledge about targeted drug delivery systems and how hydrophilic & hydrophobic drugs can be encapsulated in liposomes & polymersomes (similar to Q4d) [AME]
Targeted Drug Delivery Systems:
These systems are designed to direct drugs to specific sites in the body, which improves efficacy and reduces side effects. The use of nanotechnology, such as nanoparticles and micelles, allows for precise drug delivery to targeted cells or tissues.
Encapsulation of Hydrophilic Drugs in Liposomes:
Liposomes are spherical vesicles with a phospholipid bilayer that can encapsulate hydrophilic drugs within their aqueous core. This method is advantageous for increasing the solubility of hydrophilic drugs and protecting them from degradation in the body.
Encapsulation of Hydrophobic Drugs in Polymersomes:
Polymersomes are similar to liposomes but are made from amphiphilic block copolymers. They have a more robust bilayer structure than liposomes, making them suitable for encapsulating hydrophobic drugs within their hydrophobic membrane.
Mechanisms of Drug Release:
Both liposomes and polymersomes can release encapsulated drugs through diffusion, degradation of the vesicle material, or by environmental triggers such as pH or temperature changes, which can disrupt the vesicle membrane.
[7] Basic knowledge of the main advantage of stabilising quantum dots with carboxyilic acid containing molecules [AME]
Stabilization and Solubility: Carboxylic acid groups can be used to functionalize the surface of quantum dots, which helps stabilize them in aqueous (water-based) solutions. This stabilization is crucial because it prevents the aggregation of quantum dots and maintains their unique properties, such as fluorescence and size uniformity.
Enhanced Bioconjugation: Carboxylic acids on the surface of quantum dots facilitate the binding of biomolecules through amide bond formation. This bioconjugation is essential for biological applications, such as cellular imaging, where targeting specific biological structures or processes is required.
Electrostatic Binding: The carboxylate anions on the quantum dot surface can interact electrostatically with other ions in the environment, which enhances the dispersion and stability of quantum dots in biological and aqueous environments.
[8] Basic knowledge of the major disadvantages of using biological materials to create tissue engineering scaffolds [AME]
Immunogenicity:
Biological materials can provoke immune responses, which may lead to rejection of the scaffold by the patient’s body.
Disease Transmission:
There is a risk of transmitting diseases when using biological materials derived from human or animal sources.
Variability:
Biological materials can exhibit variability in their properties due to the natural differences between donors, affecting the consistency and reproducibility of scaffolds.
Degradation Rate:
Controlling the degradation rate of biological scaffolds can be challenging, as it must ideally match the rate of tissue regeneration.
Ethical Concerns:
The use of certain biological materials, especially those derived from human or endangered animal sources, raises ethical issues.
Cost and Scalability:
The extraction and processing of biological materials can be costly and difficult to scale, which limits their practicality for widespread clinical use.
