Engineering componants: CELLS Flashcards
What 4 tissue types are organs made up of to form a functional unit?
Muscle tissue, connective tissue, nervous tissue and epithelial tissue
Where do cells recieve nutrients and oxygen from and how do they discard waste?
Nutrients and oxygen from blood and EC fluid, discard waste via lymph nodes
Wound healing - what are the 3 main phases and what roughly happens in each?
1) inflammatory phase –> stops bleeding and clears away dead cells and microbes. This occurs via leukocytes : macrophages, neutrophils and fibroblasts
2) proliferation phase - the laying down of new tissue
3) remodelling phase - the organisation of said new tissue, this can take months/years!
Outline the process for wound healing
- Blood clots form to prevent bleeding
- Leukocytes are recruited to clean the wound (macrophages, neutrophils and fibroblasts)
- Fibroblasts lay down new tissue and produce granulation tissue / secrete collagen
- Epithelium regenerates and scar tissue forms if too much damage to ECM
How is the liver a good example of wound healing impacting regeneration?
Acute injury of the liver –> it is able to regenerate and rebuild
If the injury impacts the cells and ECM, connective tissue can become deposited, cells proliferate, the ECM is disrupted and scars form
REGEN VS REPAIR - what dictates this?
Severity of an injury –> acute, transient injury, skin can repair its normal structure
Too much damage –> cannot repair back to normal structure and scarring occurs
what is Fibrosis and Fibrous encapsulation
Fibrosis - healing of persistant tissue damage
Fibrous encapsulation –> when biomaterials are implanted, a tissue has an immune response where it treats the biomaterial as a foreign body and encapsulates it in collagen to isolate it
What are the 4 main cell sources - outline where they come from
Autologous – from person themself
Allogeneic - from another individual of the same species
Xenogeneic - different species
Syngenic - from individual who is genetically identical
CELL TYPES USED FOR ENGINEERING?
Adult stem cells - these are multipotent and easily accessible
Embryonic stem cells - derived from the blastocyst’s inner cell mass
Induced pluripotent stem cells - derived from adult somatic cells where pluripotency factors have been injected»_space; these can be cultured and kept for long periods of time
Differentiated cell types used in TE?
Which particular type is common
Fibroblasts, keratinocytes, adipocytes, osteoblasts, chondrocytes, ESCs
Chondrocytes are commonly used in TE, cartilage cells
Roughly outline cell culture process?
1) Cell cultured in growth medium with nutrients (O2, glucose and nutrients needed)
2) Leave in laminar hood and grow in incubator
Why is it important that we understand cell:material interactions
Because cells attach to the solid surface they grow from»_space; they do this via the ECM.
Important that we understand the ECM!
Why is collagen so important
- Most vital part of the ECM
- Most abundant protein in the human body
- 28 types, triple helix structure
- Stronger than steel!!!
What does the ECM consist of (give examples of each)
WATER HYDRATED GELS - proteoglycans, hyalauronan
FIBROUS STRUCTURE PROTEINS - provide tensile strength - collagen
ADHESIVE GLYCOPROTEINS - fibronectin, laminin
PROTEOGLYCANS - allow attachment of cell to ECM and form chemical bonds - Fibronectin
Fibronectin - why do we need it? What relevant sequence does it have?
Type of proteoglycan, allowing attachment to ECM via chemical bonds
Very hydrophilic, consists of glycosaminoglycan chain and protein core
Has an RGD sequence which is recognisable on the cell surface and attaches to the ECM
