Tissue engineering: Case 6

The need for implants

Implant limitations

Biocompatibility

Classes of biomaterials

Bioreactivity spectrum: relative bioreactivity of the course of implantation time

Main causes of hip implant failure

Stress shielding

Osteochondral regeneration

THR types

PMMA: how does it work?

Problems with PMMA

Bioactive coatings

Effect of loading environment

Aseptic loosening

Wear

Wear particles: the problem

Solution to wear: UHMWPE

Problems with UHMPWE

Solutions

Metal-metal: advantages and disadvantages

Ceramic on ceramic

Transplants

Regeneration over reabsorption: Resorbable bioceramics - degrade over time and be replaced by natural host tissue ( better than autografts?)

Bioglass

3D printing of scaffolds

Summary: J Jones lecture

What is a scaffold?

What surgeons want - not always what developers make

Ideal scaffold properties for regeneration

Mechanical properties of a scaffold for bone regeneration

Mechanical properties vs biodegradation: scaffolds

Interconnected porosity

Cartilage structure

Challenges with osteochondral scaffolds

Biomaterials generations

Bioceramics properties

Polymers

Manufacturing techniques

Composite

Hybrids

Tissue engineering

Strategies for tissue engineering

The need for tissue engineering

Current treatments for OA

Whole organ transplantation problems

Goal of tissue engineering

Three main pillars of tissue engineering

ACI limitations

Adult stem cells

MSCs

Tissue specific stem cells

Tissue specific stem cells advantages and disadvantages

Pluripotent stem cells

Scaffold in tissue engineering

Natural matieral scaffolds: collagen, fibrin, hyaluronon

Synthetic matierals: e.g. polymers, ceramics, bioactive glass

The importance of scaffold mechanical properties

Growth factors and signalling factors

Mechanical stimulation

Environmental factors

Cartilage regeneration: Composition

Cartilage functions

Composition of cartilage

Role of ECM in defining mechanical properties of cartilage