Essays

Question 1

Biomaterial experiments

Answer 1

1. EBSC retinal pigment epithelium- spit fighter planes
2. Bioglass- rat implant bone
3. Mechanical stimuli on stiffness
4. Cell:material interaction- cell shape controls cell fate- micropatterning of fibromectin into island- same GF,ECM but different geometry= different fates

Question 2

Scaffold experiments

Answer 2

1. 3D print human tissue- 15x15x1 myoblast- PCL pillar, thrombin solution for fibronectin gelatine and uncross links
2. Bone generation- BMP entrapped in PEG- crosslinks added site for cleavage and BMP liberated which activates osteoblasts- bone matrix

Question 3

Bioreactors

Answer 3

1. Cell seeding distribution- bone marrow stromal cells, MTT look at seeding in perfused and static
   Chondroctyes seeded and only mixed survived
2. Porcine heart- decellularising
3. Mauck et al- articular cartilage- loading pressure
4. Tammy et al- space flight conditions on osteoclasts
5. TE heart valves flex stretch flow system- increase function of heart valve
6. Pulsatile pump blood vessels
7. Vocal folds

Question 4

Skin substitutes

Answer 4

Epidermal keratinocytes layers

1. My skin- subconfluent autologous keratinocytes, diabetic foot ulcer
2. Composite substitutes- using allogenic skin incorporated into the scaffold
   - apligraf- bovine 1 collagen, fibroblasts keratinocytes- normal skin
   - OrCell- seeded fibroblast and keratinocytes onto collagen sponge

Question 5

Gene therapy

Answer 5

1. EB boy- splice site mutation in 14 intron of lambB, epidermal transplant with corrected layer
2. Make 3D skin- PSC CDB approach- 0-30 days
3. Hair follicle- from male- incutaneous transplant and orthoptic hair follicle in nude female

Question 6

Nerve regeneration

Answer 6

1. Matrigel- protein from mouse sarcoma- promote regeneration from ecm protein
2. Medial nerve , nerve conduit- close gap

Question 7

Vascularization

Answer 7

1. Folkman et al- Tumour angiogenesis, cut vasculature from tumour and it shrinks
2. Polymeric system dual GF delivery- VEGF and PDGF form mature vasculature network

Question 8

Cornea

Answer 8

1. Limbal study- long term restoration to damaged cornea- holoclur - 74/104 worked no surface problems, reduced pain, restored sight
2. cornea alternative cells- oral mucosa

Question 9

Host response

Answer 9

1. Diabetes type 1 insulin deficiency- cadaver islet cell transplantation
2. Immunoisolation- semi permeable, protect insulin

Question 10

Organ on a chip

Answer 10

1. Drug withdrawn from market- VIOXX hepatotoxic, cardiotoxic
2. PGN14N12- immmunotherapy for leukaemia- thought revolutionary but killed 6 patients in phase 1 due to difference in aa of primates and humans
3. Pulmonary inflammation- TNFa activated- release iCAM (measured)- leukocyte to capillary alveolar barrier- ecoli GFP
4. Pulmonary odema- cancer drugs IL-2, add to vascular side, permeability decreases and water fills chamber

Question 11

Regulation

Answer 11

1c GO GO TE wen bankrupt, dermal pigment, 40 patients fundraised for skim substitutes
2. Burn victims, FDA approved but delays meant it never happened