Towards Bionic Tissue Engineering (BiTE) Prof. 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 consuming 2/3 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)

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