Miltos Balidis MD,PhD,FEBOphth, President of SECRS ...(iPS) transplantation •Are the cells...

5/8/2019

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INTRODUCING NEW CONCEPTS

IN CORNEAL SURGERY

Miltos Balidis MD,PhD,FEBOphth, President of SECRS

Cairo 2019

www.ophthalmica.gr

• Αλκμαίων

• Εμπεδοκλής

• Ηρόφιλος

• Ερασίστρατος

Cairo 2019

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Life needs …..

Cairo 2019

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Vision

• Obstacles are those frightful things you

see when you take your eyes off the

goal."

. » Hannah More

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Cairo 2019

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Stromal Opacity

Alternative

strategies of

Replacement or

Removal

Replacing stroma sparing

the endothelium

DALK , FALK

Replacing with

synthetic optical

elements /

keratoprosthesis

Replacement with

Biomimetic or

bioengineered material

Acellular or cellularized

scaffold, Acornea

Regeneration of stromal

transparency with stem

cell remodeling

MSC,ESC,iPSC

Cairo 2019

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Stromal multipotent stem cells

in the limbus

Stromal stem cells next

to basal epithelial cells

Limbal biopsies contain

Stromal Stem Cells

Stromal stem cells differentiate into

keratocytes and remodel

disorganized stroma

Remodeling of stromal

scars by keratocytes,

restores transparencyStromal stem cells

1. Regenerate corneal stroma

2. Remodel activate corneal

wounds

3. Differentiate into keratocytes

4. Prevent and reverse scarring

Cairo 2019

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Topical Hepatic Growth Factor alone is Sufficient

to restore corneal transparencyin Ocular Injury

Cairo 2019

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Pluripotent stem cell

(iPS) transplantation

• Are the cells identical to the original cells?

• How long do they remain effective

• Long term potential side effects?– Oxidative stress associated with reprogramming?

• Do we still need retroviruses?Hotspots of De Novo Point Mutations in Induced Pluripotent Stem Cells Yoshihara, M et al , Cell

Reports, vol. 21, no. 2, pp. 308–315, 2017

Cairo 2019

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www.ophthalmica.gr

Stromal Opacity

Alternative

strategies of

Replacement or

Removal

Replacing stroma

sparing the

endothelium

DALK , FALK

Replacing with

synthetic optical

elements /

keratoprosthesis

Replacement with

Biomimetic or

bioengineered material

Acellular or cellularized

scaffold, Acornea

Regeneration of

stromal transparency

with stem cell

remodeling

MSC,ESC,iPSC

Cairo 2019

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Stromal substitutes

• Acellular inert material impearmeable to cells

• Acellular biomaterial as scaffold

• Biomaterial enhanced with cells at production

• Stromal substitutes entirely engineered from cells

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Tissue-engineered stromal substitute

Guo 2007,

Karamichos 2014

Karamichos 2013

Du 2010,Wu2014

Cairo 2019


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TE cornea

• Minimum risk of rejection

• Minimum need for post-surgical drugs

• Better biocompatibility and integration than

the synthetic corneas permanent corneas,

• Cost-effective

• Readily available to patients.

Cairo 2019

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1818 F Reisingeranimal keratoplasty

1835 Bigger successful PKP in pet

1838 Kisamtherapeutic xenon graft on human

1867 Power PKP with allograft

1888Von HippelLamellar xenograftsclockwise trephane

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Why DC

• DCs are potentially advantageous in

comparison to TE corneal equivalents and

KPros• the matrix has the ultrastructure of the native tissue.

• Inherent biological signals may remain within the

matrix, important for the maintenance of specific

cellular functions and phenotype

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Enzymes

• Trypsin

• Dispase

• Phospholipidases A2-PLA2

• Nucleases

• Sera

• EDTA

Cairo 2019

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Chemicals

• Alcohols

• Acid-Alcali

• Ionic Detergents • SDS

• SD

• Non ionic Detergents• Triton X

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Osmotic and Physical

• Hypo or hypertonic solutions

• Freeze thawing

• Hydrostatic pressure

• Sonication

Cairo 2019

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Decellularization

ECM, GAG’s, proteins

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Get the balance right

Cairo 2019

antigens ECM

Removal of antigens

important for graft

rejection and

inflammation

Maintaining ultrastructural

architecture

Intact ECM, proteins,

GAG’s, and biological

signals for keratocytes


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Cryolyophilized

KeratoxenograftsOdessa Institute of Eye Diseases and Tissue Therapy

•Processing with a cryoprotector

•Preserved at cryogenic temperatures (-196 ° C),

•Vacuum dryed and packaging

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Acornea

• The Acornea is a heterogeneous cornea.

• Stripped of cells, hybrid proteins and other

antigens, maintaining its natural collagen

structure.

• Able to integrate with the surrounding tissue

and foster the regeneration of its own cells.

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Generation of Bioengineered Corneas with Decellularized Xenografts and Human KeratocytesInvest. Ophthalmol. Vis. Sci.. 2011;52(1):215-222. doi:10.1167/iovs.09-4773

Analysis of NPC (top

row) and corneas

decellularized with 1.5 M

NaCl (middle row) and

0.1% SDS (bottom row).

First column: H&Eof

anterior and posterior

corneas; second column:

fiber orientation analysis

with polar plot images;

third column: azimuthal

images; fourth column:

Alcian blue staining of the

different samples; fifth

column: fluorescence

immunohistochemistry

against α-gal epitope.

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Miltos Balidis MD,PhD,FEBOphth, President of SECRS ...(iPS) transplantation •Are the cells...

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