Stem Cells in Tissue Engineering

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Questions and Answers

What is the process called when cells from a primary culture are cultured in new media?

Subculture (correct)

Passaging (correct)

Reinoculation

Isolation

What does the passage number of a cell culture indicate?

The size of the primary culture

The number of times the culture has been subcultured (correct)

The age of the culture

The duration of culture

Which of the following sources is NOT commonly associated with the isolation of MSCs?

Adipose tissue

Bone marrow

Spleen (correct)

Amnion

Which term best describes the initial collection of cells for culture?

Primary culture Signup and view all the answers

Which tissue is NOT commonly mentioned as a source for MSC isolation?

Liver Signup and view all the answers

What is the initial step in isolating MSCs from adipose tissue?

Cut the fat into small pieces Signup and view all the answers

Which staining technique is used to observe cartilage differentiation?

Alcian Blue Signup and view all the answers

What does a TE scaffold aim to mimic?

The mechanical and functional characteristics of the native ECM Signup and view all the answers

What is one of the characteristics observed when MSCs differentiate into bone?

Mineralization Signup and view all the answers

In the process of MSC isolation from dental pulp tissue, what is the primary technique used?

Cutting technique Signup and view all the answers

What is a key challenge in developing an ideal TE scaffold?

Mimicking the properties of the native extracellular matrix Signup and view all the answers

Which of the following is NOT observed during MSC characterization?

Epithelial cell differentiation Signup and view all the answers

What is the main goal of creating a TE scaffold?

To support the growth and organization of new tissue Signup and view all the answers

What is one key function of the extracellular matrix?

It anchors cells via integrins. Signup and view all the answers

Which characteristic is not an ideal feature of a scaffold?

Incompatibility with tissue Signup and view all the answers

How does the extracellular matrix relate to growth factors?

It serves as a reservoir for growth factors. Signup and view all the answers

What is a primary purpose of the scaffold in tissue engineering?

To emulate the extracellular matrix's characteristics. Signup and view all the answers

Which of the following is a mechanical property provided by the extracellular matrix?

Shape and mechanical stability Signup and view all the answers

What role does the scaffold have in relation to tissue remodeling?

It encourages tissue remodeling. Signup and view all the answers

What is one function of bioactive cues provided by the extracellular matrix?

To support cell proliferation. Signup and view all the answers

Which of the following statements is true regarding the extracellular matrix?

It plays a role in various cellular processes. Signup and view all the answers

What is the primary function of the extracellular matrix (ECM)?

To serve as scaffolding for tissues and organs Signup and view all the answers

Which components are found in the extracellular matrix?

Collagen fibers and glycosaminoglycans Signup and view all the answers

What type of ECM is in direct contact with epithelium and endothelium?

Basement membrane Signup and view all the answers

Which statement best describes the architecture of the extracellular matrix?

It has a distinct three-dimensional architecture specific to each tissue. Signup and view all the answers

What is the role of glycoproteins in the ECM?

To aid in cell signaling and adhesion Signup and view all the answers

Which category of the ECM includes all other ECM components between cells in tissues?

Interstitial matrix Signup and view all the answers

What distinguishes the mechanical properties of the ECM in different tissues?

The structural and functional molecules within the ECM Signup and view all the answers

What is one of the key categories of components found in the ECM?

Ground substances Signup and view all the answers

What aspect of scaffold design is important for supplying nutrients and allowing oxygen exchange?

High interconnectivity of pores Signup and view all the answers

Which property is NOT related to the surface characteristics of a scaffold?

Biodegradability Signup and view all the answers

What is the goal of biocompatibility testing of scaffolds?

To identify any toxic effects on the body Signup and view all the answers

Which statement correctly describes the need for biodegradation in scaffolds?

Scaffolds should be broken down to allow natural tissue development Signup and view all the answers

Which of the following biocompatibility tests assesses systemic toxicity?

ISO 10993-11 Signup and view all the answers

Which surface property would enhance cell attachment and proliferation on a scaffold?

High surface charge Signup and view all the answers

What type of immune response should scaffolds ideally elicit?

Minimal immune reaction Signup and view all the answers

What is the primary function of pore size in the context of cell infiltration?

To facilitate cellular migration and nutrient flow Signup and view all the answers

What is the primary source of embryonic stem cells (ESCs)?

Embryo Signup and view all the answers

What type of plasticity do adult stem cells (ASCs) exhibit?

Multipotent Signup and view all the answers

Which of the following statements about induced pluripotent stem cells (iPSCs) is true?

They are generated by reprogramming adult somatic cells. Signup and view all the answers

Which stem cell type is known for having tri-lineage differentiation potential?

Mesenchymal stem cells Signup and view all the answers

Which characteristic is NOT associated with adult stem cells (ASCs)?

Unlimited expansion Signup and view all the answers

What is the main purpose of cell culture in biological research?

To isolate and grow specific cell types. Signup and view all the answers

What is the main advantage of using mesenchymal stem cells (MSCs) in tissue engineering?

They possess immunosuppressive properties. Signup and view all the answers

What is meant by 'primary culture' in cell culture techniques?

Directly obtaining cells from tissues for culturing. Signup and view all the answers

Study Notes

Stem Cells and Scaffold for Tissue Engineering

Stem cells suitable for tissue engineering must be easily obtainable in large numbers, safe to implant, and able to differentiate into the necessary cell types.
Different types of stem cells used in tissue engineering include embryonic stem cells, adult stem cells, induced pluripotent stem cells, and mesenchymal stem cells.

Stem Cell Sources for TE

Embryonic stem cells (ESCs) are derived from the inner cell mass of a blastocyst and can differentiate into any cell type in the body. ESC lines were first derived from mouse blastocysts in 1981, primate embryos in 1995, and human embryos (donated preimplantation human blastocyst) in 1998.
Adult stem cells (ASCs) are undifferentiated cells present in various tissues and organs. They can be isolated from sources like bone marrow, adipose tissue, and blood vessels and differentiate into multiple cell types.
Induced pluripotent stem cells (iPSCs) are created by reprogramming adult somatic cells, such as skin cells, to an embryonic-like state. They have similar differentiation potential to ESCs and can be derived from a patient's own cells. iPSCs were discovered in 2006.
Mesenchymal stem cells (MSCs) are a type of ASC found in bone marrow, adipose tissue, and other connective tissues. They have the ability to differentiate into bone, cartilage, and fat. MSCs are often used in tissue engineering due to easy harvesting, expansion in vitro, and immunosuppressive properties.

MSCs - Isolation and Culture

Cell culture is a technique that isolates cells from animal tissue and cultivates them in a controlled, artificial environment (in vitro).
Primary culture involves directly obtaining cells from tissues and growing them until they occupy all available space or reach confluence.
Secondary culture involves isolating and culturing primary culture cells in fresh media after they reach confluence. Secondary culture is also known as subculture or splitting of cells. The passage number of a cell culture records the number of times the culture has been subcultured.
Primary harvest origins for MSCs include Amnion, placenta, bone marrow, umbilical cord and umbilical cord blood, adipose tissue, and dental pulp tissues.
MSC isolation techniques from different sources are described, including bone marrow, adipose tissue, and dental pulp.

MSC Characterization

MSCs are characterized based on their surface markers, morphology (appearance), staining patterns (using oils, reds, blues, etc.), and their ability to differentiate into desired cell lineages in vitro (in a laboratory setting), ensuring they are not contaminated with other cells.

Goals of TE Scaffold

A tissue engineering (TE) scaffold is an engineered replacement for the native extracellular matrix (ECM).
The ideal scaffold mimics the mechanical and functional characteristics of the desired tissue.
The native ECM is a three-dimensional network of proteins and polysaccharides filling the extracellular space in an organism.
The scaffold should have specific components for strength, flexibility, and provide the necessary nutrients to promote growth, differentiation, and tissue healing.
The scaffold's architecture, surface properties, biocompatibility, and biodegradability are all vital characteristics.

The Specifications for TE Scaffolds

Suitable Mechanical Performance: Mechanical strength and characteristics, including tensile strength, elastic modulus, and stiffness, are crucial for the scaffold in order to allow surgical handling and maintain integrity during implantation.
3D Architecture: Adequate scaffold porosity and pore size allow cell and nutrient penetration, tissue ingrowth, and vascularization.
Biocompatibility: The material should elicit a minimal immune reaction in the host, preventing severe inflammatory reactions that may hinder healing or cause rejection. Furthermore, the material should be compatible with cell adhesion and proliferation.
Biodegradation: The scaffold should be biodegradable at a rate appropriate to the growth of the new tissue to prevent interfering with regeneration. The breakdown products need to be nontoxic.

Biomaterials for TE Scaffold

Various materials, both natural and synthetic, are used for scaffolds to support cell attachment, proliferation, and differentiation including decellularized tissues, polymers, polysaccharides, and ceramics. Examples include silk, collagen, fibrin, gelatin, hyaluronan, alginate, agarose, chitosan, PEG, PGA, PLGA, PDLLA, and PCL. Different ceramics are also suited to certain tissue applications.

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Description

Explore the various types of stem cells used in tissue engineering, including embryonic, adult, induced pluripotent, and mesenchymal stem cells. Learn about their sources, properties, and significance in regenerative medicine. This quiz will test your knowledge on the fundamental concepts of stem cells in the context of tissue engineering.