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Biological Scaffoldsfor

Tissue Repair and Regeneration

Professor Eileen InghamInstitute of Medical & Biological Engineering

Faculty of Biological SciencesUniversity of Leeds

iMBEEngineering ‘50 active years after 50’ through multi-disciplinaryresearch, innovation, knowledge creation and translation.

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• Eileen Ingham BSc PhD; Professor of Medical Immunology [2000]

• Over 280 peer-reviewed academic research papers and 20 reviews; H-factor 42 withover 6000 citations [Web of Science]

• Recipient or co-recipient of research funding in excess of £48 million includingprestigious Wellcome, ERC, EPSRC Programme Awards with funding from BBSRC,MRC, NIH, NIHR, DTI, DoH, NHS, charities including arc and BHF and Industry

WHO AM I?

MRC, NIH, NIHR, DTI, DoH, NHS, charities including arc and BHF and Industry

• Supervised 60 PhD/MD students to successful completion

• Inventor on 10 patents [5 related to Acellular Biological Scaffolds]

• BBSRC Innovator of the Year finalist 2009

• UKRC Women of Outstanding Achievement Award for “Innovationand Entrepreneurship in Academia and Research” 2011

• Academic Founder of Tissue Regenix Group PLC 2006

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• Multidisciplinary Institute; research and innovation.

• Lead by Professor John Fisher CBE [Medical Engineer]

• Over 100 researchers

• UK’s leading bioengineering research institution and among the top ten in the world.

INSTITUTE OF MEDICAL & BIOLOGICAL ENGINEERING

• Purpose: to deliver pioneering multidisciplinary research and education in the fields ofmedical devices and regenerative medicine, underpinned by innovation and translation ofnovel therapies.

• Orthopaedic and cardiovascular applications.

• Winner of the Queens Anniversary Prize for Higher & Further Education 2012

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BIOLOGICAL SCAFFOLDS: THE CONCEPT

Start with animal/ human tissue to bereplaced

Remove cells and immunogeniccomponentscomponents

Retain extracellular matrix structureand histioarchitecture

Retain microscale biomechanicalproperties and function

Regenerate in vivo with recipientsendogenous cells

Based on hypothesis that scaffold architecture would generate micro-biomechanicalstimuli to drive appropriate cell function

Biological Scaffold

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Tissue Characterisation

Decellularisation processes

Histology

Biochemistry

Immunocytochemistry

2000-2006 CAPACITY AND CAPABILITIES

10mM Tris hypotonic buffer pH 8.0Aprotinin and EDTA 24h 4oC

0.1% SDS in hypotonic buffer

Decellularisation Process

Alpha-Gal determination

In vitro biocompatibility

In vivo biocompatibility

Large animal pre-clinical models

Uniaxial tests for soft tissues

Pulsatile flow tests

Compliance/dilation tests

Suture retention tests

Indentation/ compression tests

DNAse and RNase 3h 37oC

0.1% SDS in hypotonic bufferAprotinin and EDTA 24h RT

Sterilisation peracetic acid 0.1% 3h

PBS + Aprotinin 24h 4oC

PBS + Aprotinin and EDTA 24h 4oC

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CASE STUDY: ACELLULAR PORCINE AORTIC ROOTSNative

Acellular

Explanted after 6 months in RVOT juvenile sheep

Native Acellular

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APPLICATION OF PROCESS TO RANGE OF SOFT TISSUES

Decellularisation Protocol

PericardialCardiovascular Patch

Aortic and PulmonaryValve Conduit

Patella tendonSuperflexor Tendon

Decellularisation Protocolfor Human and Porcine

Tissue

MeniscusBlood vessels

Skin Bladder Amnion

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(1) Regeneration in vivo by recipient endogenous cells

(2) Importance of scaffold structure and architecture

• Each tissue application has a unique scaffold architecture

MECHANISMS OF FUNCTION OF BIOLOGICAL SCAFFOLDS

• Different scaffold architecture and structure for

heart valves, blood vessels, meniscus, ligament, skin……..

• Our Biological Scaffolds have tissue specific architectures that deliver

• Tissue specific bulk biomechanical properties

• Tissue specific physical and biological environment

• Appropriate environment for tissue repair - attract and support tissue regeneration,providing tissue specific micro-scale physical and biochemical architecture

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• Derived from natural structural tissue to be replaced

• Efficient cell removal

• Other biological scaffolds in clinical use have retention of cell remnants.

• Use of low concentration SDS plus proteinase inhibitors preserves tissue structure

WHAT IS UNIQUE ABOUT OUR BIOLOGICAL SCAFFOLDS?

• Others have used high concentrations of SDS and detergents that destroys tissuestructure

• No use of chemical fixatives

• Others treat acellular biological scaffolds with fixatives which prevents cells migratinginto tissues to remodel and regenerate

• Biomechanical structure and function – short and long term

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PROGRESS TO DATETissue Species Research Proof ofConcept

Develop Clinical Trial Delivery

Cardiacvalves

Human+ 2009Braz

Porcine TRG

VascularPatch

Human# NHS

Porcine T TRG 2010

Amnion Human# NHS BT TSAmnion Human# NHS BT TS

Ligament PorcineRabbits

Meniscus Porcine TRG

Bladder Porcine

Skin Human# NHSBT/.TRG

Bloodvessels

Porcine Sheep

Human# Sheep

# collaboration with NHS BT TS

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• Arteriovenous grafts with low thrombogenicity

• Surgical solutions for the replacement of tissues in the knee

Bone-meniscus for the meniscal replacement *

Bone-patella tendon bone for the replacement of the ACL*

CHALLENGES NOW BEING ADDRESSED

Bone-patella tendon bone for the replacement of the ACL*

Osteochondral grafts for treatment of cartilage defects*

• Complex hard/ soft tissue composites

• Application of technology to organs: Liver

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• Clinical need for vascular access graft for hemodialysis

• Current synthetic replacements:

Low Compliance

Low patency rates

Anastomotic intimal hyperplasia

ARTERIOVENOUS GRAFTS WITH LOW THROMBOGENICTY

Infection

• EU FW 7 SME Grant co-ordinated by Corline, Uppsala, Sweden

• TRG partner [Work Package 4]

• UoL RTD performer

Aim: To develop a non-thrombogenic AV graft using acellular bovine carotid artery createdusing the TRG/University of Leeds technology in combination with the unique heparin coatingtechnology developed by Corline.

The Corline® Heparin Surface technology, CHS™,

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• Porcine arteries unsuitable :- not long enough

• Optimised porcine artery bioprocess [patented] for bovine carotid arteries [>20cm]

• Characterised acellular bovine carotid arteries

• Biocompatible, free from xenogeneic epitope [a-Gal]

• Biomechanics equivalent to fresh tissue

AV GRAFT; IN VITRO STUDIES

• Successfully coated with Corline Heparin Surface

• Demonstrated reduced thrombogenicity in vitro

DNA content reduced to less than 50 ng/mgEquivalent or below content of examples clinical products

Fresh dCELL

a-Gal removed

Reduced thrombogenicity

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AV access model in sheep using CHS coated acellular bovine common carotid arteries110 - 120 mm length implanted in a carotid to jugular bypassOne and six month time points n = 6Control material ePTFE grafts n = 3 (one month)

PROOF OF CONCEPT OVINE MODEL: ONGOING

Head

Body

Carotidartery Jugular

vein

Strapmuscle

Graft

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Osteoarthritis• Affects circa 10% men and 20% women aged >60

years,• Estimated to be 4th leading cause of disability by 2020.• Pedisposing factors : sports, obesity

OSTEOARTHRITIS/ DEGENERATIVE JOINT DISEASE

Osteochondral graftcartilage replacement

Impact on quality of life• Pain• Psychological

Societal Impact• Direct costs circa 1% GNP [USA & Canada].• Indirect costs [loss of productivity and wages] ~ 2% GNP.

Becoming increasingly prevalent in the younger pre-retirement population

Bone-meniscus-boneMeniscus replacement

Bone-tendon -boneACL replacement

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COMPOSITE BONE SOFT TISSUE SCAFFOLDS

• Bioprocess developed

• Based on low concentration SDS

• Additional steps

• Cell removal from all regions C

Osteochondral Bone-tendon-bone

• Patent filed September 4th 2012

• Fixation “ bone to bone”

• Surgical technique used for allograft/ autograft

• Biological scaffolds from porcine /human donortissue to meet all clinical needs in the earlyosteoarthritic knee

Bone-meniscus -bone

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ACELLULAR LIVER

Aim: produce acellular human liver graftLiver tissue engineering3D scaffold for hepatocyte culture

Perfusion based approach

Fresh Acellular

93.993.0

93.791.6

97.798.1

97.196.2

98.096.9

85.0 90.0 95.0 100.0

Bile Duct

Portal Vein

Lower

Lateral

Deep

% DNA Reduction (N=3)

Successful decellularisation (> 90% DNAremoval)

Currently considering IP

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• Arteriovenous grafts with low thrombogenicity [TRG + Corline; EU FP7]

• Small and Medium Diameter Blood Vessels [TRG + NHS BT TS;

WELMEC]

COLLABORATIVE PROJECTS WITH TRG PLC

• Acellular Allogeneic Cardiac Valves [TRG + NHS BT TS; WELMEC]

• Acellular Porcine Cardiac Valves [TRG ; WELMEC]

• Meniscus Biomechanical & Biological Test Methods [TRG ; EPSRC IKC]

• Sterilisation Methods for Vascular Grafts [TRG; £60k; EPSRC DTC]

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[1] Low concentration SDS & Protease inhibitors for decellularisation

Inventors: Catherine Booth, John Fisher, Eileen Ingham; Applicant: University of Leeds; Priority date: 24/05/2001

[2] Ultrasonic modification of soft tissue matrices

Inventors: Eileen Ingham & John Fisher; Applicant: University of Leeds; Priority date: 22/05/2003

[3] Porcine bladder biomaterial

PATENTS

[3] Porcine bladder biomaterial

Inventors: Fiona Bolland, Eileen Ingham, Sotiris Korossis, Jenny Southgate; Applicants University of Leeds andUniversity of York Priority date: 29/03/2006

[4] Acellular porcine meniscus for meniscal repair/replacement

Inventors: John Fisher, Eileen Ingham, Joanne Ingram,Thomas Stapleton; Applicant: University of Leeds Prioritydate: 16/11/2006

[5] Acellular arteries [Filed September 2010]

Applicant University of Leeds

[6] Composite connective tissue and bone implants [Filed September 2012]

Applicant University of Leeds

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ACADEMIC PUBLICATIONS BIOLOGICAL SCAFFOLDSBooth, C. et al. Tissue engineering a cardiac valve prosthesis I: Development and histological characterisation of an acellular porcine scaffold. Journal of Heart Valve Diseases, 11, 457-462 (2002).

Korossis, S.A. et al. Tissue engineering a cardiac valve prosthesis II: Biomechanical characterisation of decellularised porcine heart valves. Journal of Heart Valve Diseases 11, 463-471(2002).

Wilcox, H.E.et al. Biocompatibility and recellularization potential of an acellular porcine heart valve matrix. The Journal of Heart Valve Disease 14; 228-237 (2005).

Korossis, S.A. et al. In vitro assessment of the functional performance of the decellularised intact porcine aortic root. The Journal of Heart Valve Disease 14; 408-422 (2005).

Knight, R.L.et al. Tissue engineering of cardiac valves: reseeding of acellular porcine aortic valve matrices with human mesenchymal progenitor cells. Journal of Heart Valve Diseases 14; 806-813 (2005).

Mirsadraee, S. et al. Tissue engineering of pericardium: development and characterisation of an acellular human pericardial matrix. Tissue Engineering 12:763-73. (2006)

Wilshaw, S.P.et al. Production of an acellular amniotic membrane matrix for use in tissue engineering. Tissue Engineering 12; 1-13 (2006).

Yow, K.H. et al. Tissue engineering of vascular conduits. British Journal of Surgery, 93; 652-661 (2006).

Bolland, F. et al. Development and characterisation of a full thickness acellular porcine bladder matrix for tissue engineering. Biomaterials 28; 1061-1070 (2007).Bolland, F. et al. Development and characterisation of a full thickness acellular porcine bladder matrix for tissue engineering. Biomaterials 28; 1061-1070 (2007).

Oswal, D. e al. Biomechanical characterisation of decellularised and cross linked bovine pericardium. Journal of Heart Valve Disease 16; 165-174 (2007).

Ingram, JH. et al.The use of ultrasonication to aid recellularisation of acellular natural tissuescaffolds for use in ACL reconstruction Tissue Engineering 13; 1561-1572 (2007)

Mirsadraee, S., Wilcox, H.E., Watterson, K.G., Kearney, J.N., Hunt, J., Fisher, J & Ingham, E. Biocompatibility of acellular human pericardium. Journal of Surgical Research 143; 407-414 (2007).

Stapleton, T.W. et al. Development and characterisation of an acellular porcine medial meniscus for use in tissue engineering. Tissue Engineering Part A. 14; 505-518 (2008)

Wilshaw, S.P.et al. Biocompatibility and potential of acellular human amniotic membrane to support the attachment and proliferation of allogeneic cells. Tissue Engineering part A. 14; 463-472 (2008)

Derham, C.et al.. Tissue engineering small-diameter vascular grafts: preparation of a biocompatible porcine ureteric scaffold. Tissue Engineering Part A. 14; 1871-1882 (2008).

Wilshaw SP,et al. Investigation of the antiadhesive properties of human mesothelial cells cultured in vitro on implantable surgical materials. Journal of Biomedical Materials Research Part B. Applied Biomaterials 88;49-60 (2009).

daCosta, FD.et al.Thirteen years experience with the Ross operation. Journal of Heart Valve Disease 18: 84-94 (2009).

Wang, L. et al. Factors influencing the oxygen consumption rate of aortic valve interstitial cells: application to tissue engineering. Tissue Engineering Part C. 15; 355-363 (2009).

Stapleton TW. et al. Investigation of the regenerative capacity of an acellular porcine medial meniscus for tissue engineering applications Tissue engineering part A 17; 231-242 (2011).

Kheir E. et al. Development and Characterization of an Acellular Porcine Cartilage Bone Matrix for Use in Tissue Engineering. J. Biomed Mater Res Part B [in press 2011]

Wilshaw SP Rooney P. Berry H. Kearney JN. Homer-Vanniasinkam S. Fisher J. Ingham E. Development and Characterisation of acellular allogeneic arterial matrices. Tissue Engineering A. 18; 471-483 (2012).

Owen, K., Wilshaw, S, Homer-Vanniasinkam, S., Bojar, R., Berry, H. Ingham, E. Assessment of the antimicrobial activity of acellular vascular grafts. European Journal of Endovascular Surgery. 43; 573-581 (2012).

Tatterton, M., Wilshaw, S, Ingham, E. Homer-Vanniasinkam, S. The use of anti-thrombotic therapies in reducing synthetic small diameter vascular graft thromobosis. Vasc & Endovasc Surge46; 212-222 (2012).

Hogg, P., Rooney, P., Ingham, E., Kearney, JN. Development of a decellularised dermis. Cell & Tissue Banking [Epub 2012]

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THANK YOU

References: www.imbe.org.uk