This document discusses vascular grafts and implants. It defines them as conduits or artificial tubes used to redirect blood flow when blocked by disease. Grafts can be autologous veins, allografts from other people, or artificial grafts made of materials like PTFE, Dacron, or polyurethane. Key properties for grafts include controlling thrombosis and inflammation, having strength and flexibility similar to blood vessels, fatigue resistance, and biocompatibility. The document also discusses polymers used in grafts, both non-degradable ones and degradable ones, as well as growth factors that can help with blood vessel formation.

1. VASCULAR IMPLANTS & GRAFTS
Sourabh Santosh Gurav
BE Biotechnology
2019

2. What are Vascular Grafts/implants ?
• Conduits or artificial tubes
• Redirect blood flow between blocked by any
disease (ischemia,Atherosclerosis or sometimes
for Haemodialysis)
• Grafts can be-
1. Autograft (own vein)
2. Allograft (vein from different person)
3. Artificial grafts of Teflon (PTFE) ,Dacron (PETP)
or polyurethane (PU)

3. Important features of graft :
• Control Thrombosis & inflammation
• Tensile strenght & viscoelasticity of blood
vessel
• Fatigue resistance tissue with long term
durability.
• Vessel tone, platelet activation & leukocyte
adhesion
• Other-infection resistance,suturability and off-
the-shell availability.

4. Synthetic
polymer
Coating
composition
EC function In-vivo system Explant histology
ePTFE Fibrin glue with
FGF-1 and
heparin
Canine
thoracoabdomi
nal position
EC confluence, minimal
intimal hyperplasia,
increased capillarization,
increased collagen content
ePTFE P15 peptide In vitro, 100%
HUVEC
confluence on
treated
polymer at
day 8
Arteriovenous
grafts in sheep
Decreased thickness of
neointimal hyperplasia
and increased
endothelialization
ePTFE Growth factor -
reduced
Matrigel™-
containing VEGF
High
expression of
bFGF and a
low
expression of
TGF-β in
VEGF-treated
EC
Rat abdominal
aorta
Increased EC rate,
increased myointimal
hyperplasia and SMC
density

5. Polymers for making grafts
Non degradable polymers
Degradable polymers
• Polytetrafluoroethylene
• Dracon
• Polyurethane
• Functionalization of polymers via
chemical modification and
coating enables
endothelialization and
thromboresistance
• Enable vacular
modelling
• Ex: polyglycolic
acid,polyhydroxyalkaln
oates,polycaprolactone
and polyethylene glycol
• Used for cell seeded
scaffolds
• Functionalized with
proteolytic sites for
controlled release of
bioactive molecules
• Biopolymers
• Collagen & fibre gel

6. Stent

7. Growth factors that help in blood
vessel formation :
• Acidic Fibroblast Growth factor
• Vascular Endothelial growth factor (VEGF)
• Basic fibroblast Growth Factor
wormlike robot designed to wend its way through the maze of tiny blood vessels inside the
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