Towards Bionic Tissue Engineering (BiTE)

Prof. Paolo MacchiariniProf. Paolo Macchiarini

Tissue Engineering approach

2 D in vitro cell expansion/differentiation

Scaffold seeding

biopsy

3 D graft culture

implantation

Scaffold obtaining

transport

Limitations

in vitro cell culture

• sterility risks• just in time with scheduled operative intervention

• cell transformation• oncogene activation• sterility risks• qualitative and functional changes

graft transport

biopsy •cell are patient property• cellular protocol can not be standardized

Current tissue engineering products are too expensive and risky from a manufacturing point of view

Time consuming2/3 weeks to obtain graft

significant costs

Ideal solution

The whole process should be ideally done intraoperatively eliminating the need of cell

transportation and manipolation

The manufacturing of the graft should be done within

minutes to make any tissue of choice

Bionic Tissue Engineering (BiTE)

Permissive factors

Trauma cytokines, such as IL-6, IL-1β and TNF-α

To enhance the activaction of a permissive situation of wound healing

Recruitment factors

To increase the number of stem cells both in situ and in peripheral circulation

Intraoperativatively can be used alternatively to in situ loading of the graft with prepared stem cells

Granulocyte-macrophage colony-stimulating factor (GM.-CSF) Granulocyte colony-stimulating factor (G-CSF)

Boosting factors

To enhance remodelling, reduce inflammation and activate stem cells to propagate and to protect against ischemia

Erythropoietin (Epo)

Erythropoietin (Epo)

The mRNA expression profile of the erythropoietin receptor (Epo R) and of the tissue protective submit of the erythropoietin receptor (β-CR) in different mouse tissues. GAPDH was used as a housekeeping gene.

Many tissues (including skin) express erythropoietin receptors and the tissue protective submit of the erythropoietin receptor

We decide to use it as an “enhancing” factor in regeneration process

Human dermally derived stem cells (FmSCs) proliferation

Potential role of erythropoietin in acute and chronic wounds

Results indicated both an inhibitory role of EPO in the absence of cytokines (late phase of trauma) and a supportive, boosting activity of

EPO in the presence of trauma cytokines (as IL-6).

complete and stable reepithelialization of the split-thickness skin graft donor site achieved seven days after the operation

topically treated with EPO

local treatment sessions with EPO

granulation tissue formation was obtained and provided an highly vascularized wound bed for successful split-thickness skin grafting.

It is possible that in trauma, EPO ceases its inhibitory role and reverts to a clinically relevant boosting function.

EPO may be an important therapeutic tool for the topical treatment of acute and chronic wounds.

Commitment factors

To control shifting of stem cells towards a commitment

TGF has been by us used to control in vivo differentiation towards cartilage rings to

achieve long term sustainability

If a co-stimulation occurs in the presence of an appropriate scaffold, the cells are triggered to achieve a strong and high

quality remodelling activity

The BiTE concepts

Remodelling activity is better, faster and more tightly controlled than in any in vitro activity

Bionic concept towards worldwide tissue engineered

tracheal replacement