Manifestation of Novel Social Challenges of the European Unionin the Teaching Material ofMedical Biotechnology Master’s Programmesat the University of Pécs and at the University of DebrecenIdentification number: TÁMOP-4.1.2-08/1/A-2009-0011

COMMERCIAL PRODUCTS (1)

Dr. Judit PongráczThree dimensional tissue cultures and tissue engineering – Lecture 21

Manifestation of Novel Social Challenges of the European Unionin the Teaching Material ofMedical Biotechnology Master’s Programmesat the University of Pécs and at the University of DebrecenIdentification number: TÁMOP-4.1.2-08/1/A-2009-0011

TÁMOP-4.1.2-08/1/A-2009-0011

Organ failureOrgan failure is organ dysfunction to such a degree that normal homeostasis cannot be maintained without external clinical intervention.• Recently, a curative therapy for organ

failures is only organ transplantation• Regenerative medicine offers the solution to

avoid graft rejection, the most common complication of transplantation

TÁMOP-4.1.2-08/1/A-2009-0011

Regenerative medicineRegenerative medicine is the process of creating living, functional tissues to repair or replace tissue or organ function lost due to damage, or congenital defects.It has the potential to solve the problems of:• the shortage of organs available for donation

compared to the number of patients that require life-saving organ transplantation

• organ transplant rejection, since the organ's cells will match that of the patient

TÁMOP-4.1.2-08/1/A-2009-0011

Commercialization of tissue engineering• Rapid development of tissue engineering

allows the commercialization of several products

• Cellular therapies offer therapeutic solutions for serious diseases like organ failure

• More and more products are approved for regular clinical use

TÁMOP-4.1.2-08/1/A-2009-0011

Cardiovascular diseases

Aortic valve

Tricuspid valve

Bicuspid valve

Pulmonary valve

Right coronaryartery

Left coronaryartery

Heart valves

TÁMOP-4.1.2-08/1/A-2009-0011

Artificial heart valves • Mechanical heart valves are made of

biocompatible metal alloys and plastics• Durable structure, may last for many years• The non-biological surface of implants may

cause blood clotting disturbances • Bacterial infection is a serious risk

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Biological heart valves• Valves of animals, like pigs, which undergo a

decellularization procedure in order to make them suitable for implantation in the human heart.

• Other types of biological valves (made from decellularized equine or bovine pericardium) are sewn to a frame

• They are less durable than mechanical valves

TÁMOP-4.1.2-08/1/A-2009-0011

Tissue engineered heart valvesScaffolds seeded with endothelial cellsPerspective: • Enhanced durability• No clotting disorders• No increased infection risk• Similar mechanical properties to that of

native valves• BMMC seeded TE heart valves are available

but only for the pulmonary circulation (right heart side)

TÁMOP-4.1.2-08/1/A-2009-0011

Replacement of blood vessels• Arterial „organ failure” occurs mainly as a

result of atherosclerosis• Venous „organ failure” occurs most

frequently in venous varicosity• Replacement of damaged organs: only

arteries• Autografts, xenografts, artificial stents or

blood vessels

TÁMOP-4.1.2-08/1/A-2009-0011

Vascular tissue engineering• Xenografts: decellularized veins, ureters or

intestinal submucosa from animals (canine, porcine, rabbit origin mainly)

• Recently, human allografts are used also• PCLA-PGA copolymer heart valve constructs

seeded with BMSC in paediatric patients

TÁMOP-4.1.2-08/1/A-2009-0011

Developments in vascular TETissue printing of a blood vessel:• Cells: mixture of

smooth muscle and endothelium

• Spontaneous structure will form

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Vascular grafts• Vascular grafting in surgery uses mainly

autografts: the patient’s own veins or arteries are used to bridge closures on blood vessels.

• Example: CABG surgery• Vascular stenting: Percutaneous Coronary

Intervention (PCI), Abdominal Aortic Aneurysm treatment

• Artificial blood vessel: Aortofemoral bypass

TÁMOP-4.1.2-08/1/A-2009-0011

Vascular tissue engineering• Xenografts: decellularized veins, ureters or

intestinal submucosa from animals (canine, porcine, rabbit origin mainly)

• Recently, human allografts are used also• PCLA-PGA copolymer heart valve constructs

seeded with BMSC in paediatric patients

TÁMOP-4.1.2-08/1/A-2009-0011

Tissue engineered blood vessel• TE blood vessels are used only in low pressure pulmonary

circulation• These grafts are not durable enough to withstand high arterial

pressure

Small-veinharvest

Cell seedingon polymer

Cell isolation

Cell expansion

Tissue-engineered graft

TÁMOP-4.1.2-08/1/A-2009-0011

TEBV production• HUVEC and SMC were grown in conventional

tissue culture flasks to form a monolayer which could be peeled off

• Monolayers were wrapped around inert tubular supports to form concentric layers

• Inner membrane: dehydrated fibroblast sheet• Smooth muscle cells formed the second

sheet• Fibroblast sheet was rolled on to form an

adventitia• Endothelial cells were seeded on the inner

surface

TÁMOP-4.1.2-08/1/A-2009-0011

Cartilage injury and regeneration• Cartilage injury: acute or chronic• Acute injury: mainly traumatic• Chronic injury: inflammation/degeneration• Arthritis/Arthrosis• Regeneration is slow and in case of massive

damage or chronic disease, degeneration occurs

• Heavily effects life quality and frequently occurs in the developed world

TÁMOP-4.1.2-08/1/A-2009-0011

Challenges for cartilage TE• Hyalinous cartilage, not fibrous cartilage

needed• Avascular tissue, chondrocytes have low

metabolic rate• Mechanical stimulation of engineered

construct is necessary for good results

TÁMOP-4.1.2-08/1/A-2009-0011

Autologous chondrocyte implantation (ACI) I• 200-300 mg cartilage is harvested by

arthroscopically from a less weight bearing area (intercondylar notch superior ridge of the medial or lateral femoral condyle)

• The matrix is digested enzymatically, chondrocytes are isolated

• Chondrocytes are cultured in vitro for approximately four to six weeks

TÁMOP-4.1.2-08/1/A-2009-0011

Autologous chondrocyte implantation (ACI) II• Cultured chondrocytes are applied on the

damaged area during an open-knee surgery (also called arthrotomy). These autologous cells should adapt themselves to their new environment by forming new cartilage.

• During the implantation, chondrocytes are applied on the damaged area in combination with a membrane (tibial periosteum or biomembrane) or pre-seeded in a scaffold matrix.

TÁMOP-4.1.2-08/1/A-2009-0011

Autologous chondrocyte implantation (ACI) III

Biopsy ofhealthy cartilage

Cultured chondrocytesinjected under patch

Periosteal patchharvested from tibia

Damaged cartilage(Lesion)

Tissue culture ofisolated chondrocytes

TÁMOP-4.1.2-08/1/A-2009-0011

Commercial products for ACI• Carticel® service: Genzyme• Harvested cartilage is sent to Genzyme• Release of chondrocytes, culturing and

proliferation of chondrocytes are performed by the firm

• The surgeon receives the ready-to-implant differentiated cells

TÁMOP-4.1.2-08/1/A-2009-0011

Matrix-induced ACI (MACI)• Harvested chondrocytes are expanded on

hyalin or collagen matrices• No significant difference in the clinical

outcome between ACI and MACI• Use of MSCs in MACI are in trial currently• Main challenge: differentiation towards hyalin

cartilage instead of fibrous cartilage• Many different matrices are used

COMMERCIAL PRODUCTS (2)

Dr. Judit PongráczThree dimensional tissue cultures and tissue engineering – Lecture 22

Manifestation of Novel Social Challenges of the European Unionin the Teaching Material ofMedical Biotechnology Master’s Programmesat the University of Pécs and at the University of DebrecenIdentification number: TÁMOP-4.1.2-08/1/A-2009-0011

TÁMOP-4.1.2-08/1/A-2009-0011

Bioartificial liver Assist Device• Liver has remarkable regeneration capacity

on its own• Liver replacement treatments are applied in

both acute and chronic liver failure• Bridges the time until a suitable donor is

found• Support until the transplanted liver starts

working• Treatment option for acute-on-chronic liver

failure• Treatment in acute liver failure: replacing

liver detoxification function until the patient’s own liver regenerated on its own

TÁMOP-4.1.2-08/1/A-2009-0011

Liver dialysis• Dialysis-like solutions• No living cells used • Ammonia causes encephalopathia• Extracorporeal detoxification

TÁMOP-4.1.2-08/1/A-2009-0011

Bioartificial liver

Patient’splasma

Oxygen

PKM-19 Liver cells

Plasmafilter

Bioreactor

TÁMOP-4.1.2-08/1/A-2009-0011

ELAD® bioartificial liver Blood circuitUltrafiltrate circuitGlucoseELADTM

ELADTM

ELADTM

ELADTM

Plas

ma

filte

r

Oxyg

enat

or

Pumpingsystem

Reservoir

Blood pump

Ultrafiltratepump

Recirculationpump

Glucoseinfusion pumpPriming

infusion line

Heparininfusion

Incubator

Cell

filte

r

TÁMOP-4.1.2-08/1/A-2009-0011

Cell-free ELAD: MARS

MarsFlux Dialyzer

diaMarsFluxAdsorption columns

diaFluxDialyzer

Blood circuit Mars-Albumin circuit Dialysate circuit

Bloodpump

Albuminpump

Activatedcharcoal

Anionexchange

resin

TÁMOP-4.1.2-08/1/A-2009-0011

Skin grafting and replacement• Burn injuries• Chronic wounds, e.g. diabetic or PAD ulcers• Cosmetic surgery

TÁMOP-4.1.2-08/1/A-2009-0011

Structure of the skin

Epidermis

Dermis

Fat

Sweat gland

Erector pili muscleHair

Sebaceous gland

TÁMOP-4.1.2-08/1/A-2009-0011

Purpose of skin grafting• Restore the barrier function → keratinocytes• Recently no nerve, vascular, sweat glands or

hair follicles can be included into the skin

TÁMOP-4.1.2-08/1/A-2009-0011

Split-thickness grafts• Full thickness burns → dermis AND epidermis

are both lost• Partial thickness burns → epidermis is largely

intact• If more, than 30-40% body surface is burnt,

TE products are welcome by surgeons• Smaller surface burns may be cured with split

thickness autografts

TÁMOP-4.1.2-08/1/A-2009-0011

Autologous skin grafts

Skin is meshed to cover a large wound

Graft taken frompatient’s

healthy skinWound

TÁMOP-4.1.2-08/1/A-2009-0011

Integra® skin replacement1. A patch of synthetic skin is

placed on top of damaged tissue

Undamaged dermis

Silicone membrane

Undamaged epidermis

Underlying tissue

Synthetic skin patch with silicone membrane

Blood vessels forming

3. The blood vessels restart blood flow to the area and the silicone

membrane is removed

2. The patch contains chemicals that trigger growth of new blood

vessels and proteins for skin regeneration

7 days after application 14+ days after application

4. A small graft of the patient’s own skin replaces the silicone

membraneMeshed

skin graft

14+ days after application

5. The skin graft eventually creates a smooth surface of

regenerated skin

Regenerated skin

35+ days after application

Restarted blood flow

TÁMOP-4.1.2-08/1/A-2009-0011

Cultured Epithelial Allograft (CEA)• CEA alone• Integra combined with CEA