Injured animals treated with GRNOPC1 displayed significant improvement in a variety of functional parameters compared to control groups. GRNOPC1-treated animals had improved hind limb locomotor control. Paw placement, stride length and paw rotation all significantly improved compared to controls. When the GRNOPC1-treated animals were examined histologically, increased remyelination of axons in the injury site was observed compared to that in the control animals. An increased number of axons were also observed in the vicinity of the injection within the injury.
Stem cells in orthopaedics
STEM CELLS INORTHOPAEDICS
HISTORY 1998, University of Wisconsin-Madison James Thomson Isolated cells from the inner cell mass of the early embryo, and developed the first human embryonic stem cell lines.
HISTORY1999 - First Successful human transplant of insulin-making cells from cadavers2001 - President Bush restricts federal funding for embryonic stem-cell research2002 - Juvenile Diabetes Research Foundation International creates $20 million fund-raising effort to support stem-cell research2002 - California ok stem cell research2004 - Harvard researchers grow stem cells from embryos using private funding23 nations permit some type of research on embryonic stem cells (excludesthe United States)
CELL Building block of body3 main typesEctoderm – skin, hair, eye lens, nervesMesoderm – bone, tendon, muscle,ligament, heart, blood vessel, kidneyEndoderm – stomach, mouth, intestine,colon, lung
STEM CELLUndifferentiated, primitive cellsSelf renewalAbility to divide for indefinite periodsPotential to differentiate into differenttypes of cells.Rare In Embryo – supply new cells for growth In adults – repair cells
SOURCES OF STEM CELLS3 main sources Embryos Adults Umbilical cord. Microscopic 20x view of a colony of undifferentiated human embryonic stems cells
ADULT MSCCan reduce swelling and abnormal immune responsesInflammatory ArthritisSLEIBDMultiple Sclerosis“21st CENTURY PENICILLIN”
ADULT MSCWhere do they live ?Bone marrowAdipose tissueBlood (very few)Joint tissue (very few)They are very rare cells(1 in 10000 marrow nucleated cells)60 ml marrow aspirate yields only 70 – 90thousands stem cells107 to 108 required for therapeutic levelsCan be grown in lab to yield more
ADULT MSCFor orthopedic applications, two maintypes of MSC’s have been usedBone marrow derivedTaken via a needle through a bonemarrow aspirate.Adipose derived.Obtained via liposuction.For orthopedic applications, fat derivedMSC’s consistently and dramatically underperform bone marrow derived cells.In studies of cartilage repair, bone repair,and soft-tissue repair, bone marrowderived MSC’s are much more adept atthese tasks.
ADULT MSCAdvantages of MSCAUTOLOGOUS.NO MAJOR ETHICAL ISSUES (UNLIKEEMBRYONIC STEM CELLS).CAN BE EXPANDED IN VITRO –UNLIMITTED SUPPY OF THERAPEUTICCELLS.DOES NOT EXPRESS HLA II ANTIGENS –ALLO TRANSPLANTATION POSSIBLE.STRONG EVIDENCE OF IN VITRO AND Cultured Stem CellsIN VIVO DIFFERENTIATION.
STEM CELL TRANSPLANTTwo sourcesAllograftTrue stem cells do not have any HLAantigen, therefore they need not bematched.It may be possible to transfer geneticdisease through stem cell transplantAutograftOnly safe option for next 20 – 30 yrs Cultured Stem Cells
STEM CELLS IN ORTHOPAEDICSThe challenge in Orthopaedics is to Regenerate and Repair damaged and diseased musculoskeletal tissuesCRITICAL BONE DEFECTS & NON UNIONSAVASCULAR NECROSIS FROM FROMCARTILAGE REPAIR REPLACEMENT REMOVALLIGAMENTS AND TENDON INJURIES TO TOMENISCUS REPAIR REGENERATE REPAIRSPINAL CORD REGENERATIONINTERVERTEBRAL DISC DEGENERATIONMUSCULAR DYSTROPHIES Vats A, Tolley NS, Buttery LD, Polak JM. The stem cell in orthopaedic surgery. J Bone Joint Surg Br.2004;86:159-64. Lee EH, Hui JH. The potential of stem cells in orthopaedic surgery. JBJS Br. 2006 88(7):841-51.
STEM CELLS INCRITICAL BONE DEFECTS & FRACTURE NONUNION
STEM CELLS IN BONE HEALINGMSC can be used to: Enhance bone regeneration and union in critical bone defects Non union Physis regeneration in children Improve bone quality in Osteogenesis imperfecta
STEM CELLS IN BONE HEALINGMSCs are able to be differentiated in osteoblasts under the influence of growth factors - BMPs,PDGF, transforming growth factor beta, IGF, fibroblast growth factor, and PTH.
STEM CELLS IN BONE HEALINGMethods to increase MSC population and its osteogenic differentiation in thepathological area:(i) a local injection of bone marrow aspirates,(ii) a preliminary culture of the bone marrow aspirate to increase the number ofMSC cells,(iii) a preliminary culture of the bone marrow aspirate to produce an expansionand an osteogenic differentiation of the MSC,(iv) a genetic modification of the injected MSC to increase the secretion of growthfactors like BMP and VEGF
STEM CELLS IN BONE HEALINGThe current standard of treatment for significant fractures Surgical fixation of the fracture with hardware to stabilize the site of injury.Bone defects Bone allografts have been used for over 50 years to fill defects >5 cm However, the failure of the graft can occur in up to 60% of patients at 10 years. Wheeler DL, Enneking WF. Allograft bone decreases in strength in vivo over time. Clin Orthop Rel Res. 2005 435:36-42.
STEM CELLS IN BONE HEALINGPercutaneous autologous bone-marrow graftingAn effective and safe method for the treatment of an atrophic tibial diaphyseal nonunionBone marrow aspirated from the iliac crest contains mononucleated cells.These cells can be used to obtain bone healing of non-unions.Autologous bone marrow-derived MSCs integrated into ceramic scaffolds andimplanted in bone defects of several different large animal models have exhibitedsignificant regeneration of bone. Bruder SP, Kraus KH, Goldberg VM, Kadiyala S. The effect of implants loaded with autologous mesenchymal stem cells on the healing of canine segmental bone defects. JBJS Am. 1998 80(7):985-96.
CLINICAL TRIALS IN NON UNIONUnlike animals, in humans, BM aspirates implantations were until now used.BM Aspirate. 2005 - Results of BM grafting in 20 tibial Non UnionUnder LA, 3–5ml of BM was aspirated from the Ant Iliac crest and injected immediately percutaneously into and about the NU site. Subsequent aspirations were performed 1 cm posterior to the previous site until a max of 15ml of marrow was injected.Injections were repeated at 4–6 weeks if there was no radiological evidence of callusformation.Failure - if there was no clinical and radiological union at 6 wks following the 3rd injection.The results revealed clinical and radiological bone union in 15 out of 20 patients (75%), withan average time to union following the first injection of 14 weeks.Four patients (20%) showed no evidence of union and were considered a failure. A. Goel, S. S. Sangwan, R. C. Siwach, and A. M. Ali, “Percutaneous bone marrow grafting for the treatment of tibial non-union,” Injury, vol. 36, no. 1, pp. 203–206, 2005.
CLINICAL TRIALS IN NON UNIONConcentrated BM Aspirate. Only one trial using a concentration of the BM aspiratewas published.2005 - Results of a retrospective study including 60 tibial Non unionUnder GA, 300 ml BM were aspirated from both ASIS, then filtered and concentratedby centrifugation on a cell separator. The 50ml concentrated bone marrow wasinjected in NU.Weight bearing was not allowed during min 1 month until a callus appeared.Failure was considered when no healing existed after 6 months.In 53/60 (88%) patients, bone union was obtained in mean 12 weeks (range 4–16week).They quantified the number of injected MSC and found a significant lower count ofMSC in the negative cases. PH. Hernigou, A. Poignard, F. Beaujean, and H. Rouard, “Percutaneous autologous bone-marrow grafting for nonunions: influence of the number and concentration of progenitor cells,” JBJS Am, vol. 87, no. 7, pp. 1430–1437, 2005.
STEM CELLS IN NON UNION 1. 160 mm long non union50/M, taxi driver, RTA - Sub Trochantric # Femur 2. FixDeformed united boneRx – Long Cephalomedullary nail and non wt bearing 3. Defect at fracture siteHis bone never united in 3 years and was wheelchair bound. 4. Removal of implant
STEM CELLS IN NON UNIONBone marrow cells were taken from the pelvicbone around 60ml, processed for stem cellstherapy.Removal of nailClearing of all fibrotic tissue from non union siteFixation with extra long plate screwsBone graft for defectStem cells therapy (autologus bone marrow cellsfor early and sure union)Amazing results seen at the end of six weeks
Recent research on a drug FDA approved in 2002 for Osteoporosis, Forteo (Teriparatide)suggests that it may enhance release of adult stem cells to heal bone fractures.In the preliminary data, 93% of 145 patients with non-healing or delayed healingfractures showed significant healing and pain relief after being on teriparatide for only8 to 12 weeks. Bukata SV, Kaback LA, Reynolds, DG, et al. 1-34 PTH at physiologic doses in humans shows promise as a helpful adjuvant in difficult o heal fractures: an observational cohort of 145 patients. Presented at: 55th annual meeting of the Orthopaedic Research Society; Feb. 22–25, 2009; Las Vegas, Nevada. Paper No. 227.
CLINICAL TRIALS IN OSTEONECROSIS2002 - Results of a noncontrolled study of femoral head osteonecrosis.The correct level of evidence seems to be level IV.The volume of BM aspiration made under general anesthesia was 300 ml. Afiltration and a concentration by cell separator were performed. The final volumeto inject into the necrotic area was 50ml.The patients were followed up from 5 to 11 yrs with a mean of 7 years.When patients were treated before collapse, THR was done in 9 of the 145 hips.THR was necessary in 25 hips among the 44 hips operated after collapse. P. Hernigou and F. Beaujean, “Treatment of osteonecrosis with autologous bone marrow grafting,” Clin Ortho Rel Res. no. 405, pp. 14–23, 2002.
CLINICAL TRIALS IN OSTEONECROSIS2004 – A controlled, double blind, prospective study including 18 femoral head ONbefore collapse treated by core decompression using a 5mm trephine with or withoutconcentrated BM aspirate.The method to obtain and to prepare BM was the Hernigou’s method.After 24 month follow up,There was a significant reduction in pain and joint symptoms within the BM graft group(P = .021).5 of the 8 hips in the control group had deteriorated with appearance of a collapse of thefemoral head, whereas only 1 of the 10 hips in the BM graft group had progressed to thisstage (P = .016).Survival analysis showed a significant difference in the time to collapse between thetwo groups. In addition, in the BM graft group, the volume of the necrotic lesiondecreased by 35%. V. Gangji, J.-P. Hauzeur, C. Matos, V. De Maertelaer, M. Toungouz, and M. Lambermont, “Treatment of osteonecrosis of the femoral head with implantation of autologous bonemarrow cells: a pilot study,” JBJS Am, vol. 86, no. 6, pp. 1153–1160, 2004.
CLINICAL TRIALS IN OSTEONECROSIS2009 - Results of 59 ON of the femoral head (before or after collapse) in a prospectivenon-controlled study.The 100–180 ml BM aspirate was concentrated to 30–50 ml.The implantation into the necrotic area was done through 2-3 holes made using atrocart with a 3.5mm outer diameter.The follow up was mean 27 month (range: 12–40).Clinically, the overall success was deemed in 80% and hip replacement was made in7/59 hips (11.9%). B.-L. Wang, W. Sun, Z.-C. Shi et al., “Treatment of nontraumatic osteonecrosis of the femoral head with the implantation of core decompression and concentrated autologous bone marrow containing mononuclear cells,” Archives of Orthopaedic and Trauma Surgery, pp. 1–7, 2009.
STEM CELLS IN CARTILAGE REPAIR Articular Cartilage Injury: A permanent injuryPoor vascularity…No healing potentialAdult chondrocytes don’t migrate or replicate to fill defectsInjury begins an inexorable cascade of events both chemical and then mechanical leading toward degenerative joint disease.May progress to end stage arthritis
Treatment Options for the Cartilage Bio-surgeon in 2009C AutologousL Debridement & Chondrocyte Osteochondral MicrofractureI Lavage Implantation GraftingNICALUTILITY Palliative Reparative Restorative
ACI is a 2 stage procedure:Biopsy Procurement Arthroscopic harvest from non- weight bearing, non-articulating surface (Best: inter-condylar notch)2nd stage An open surgical implantation of cells under a periosteal patch sewn in with 6-0 suture.
STEM CELLS IN CARTILAGE REPAIRTissue engineering approaches for articular cartilage defects utilize the scaffoldapproach for growth and insertion of in vitro derived tissue.One recent study attempted to insert in vitro cartilage grown from MSCs grownon scaffolds made of polyglycolic acid into articular cartilage defects on a series ofrabbits.While the study illustrated that in vitro tissue constructs could be used to repairosteochondral defects, there were limitations to the effectiveness of themechanical properties of the graft that still need to be optimized.
STEM CELLS IN LIGAMENT REPAIRThe current standard of treatment for significant tendon and ligament tears is surgery.Auto or allogenic tendon or ligament grafts are used to replace the torn tissue.However, long-term clinical outcomes cannot exceed an 85-90% success rate.Success rate is limited by three main factors Delayed incorporation of the graft into the bone Failure to recreate the complex anatomy of the native ACL Unpredictability of the long term functional strength and fixation of the graft. Fu FH, Musahl V. Review Article: The future of knee ligament surgery. J Orthop Surg. 2001 9(2):77-80.
STEM CELLS IN ACL RECONSTRUCTIONImproved Osteointegration of graftThe remodeling of the graft and its complete integration into bone is not completeuntil 6 months after surgery.Use of synovial MSCs into a bone tunnel from the tibial plateau to the tibial tuberosityshowed accelerated tunnel healing and early remodelling of tendon-bone junction. Lim JK, Hui J, Li L, Thambyah A, Goh J, Lee EH. Enhancement of tendon graft osteointegration using mesenchymal stem cells in a rabbit model of anterior cruciate ligament reconstruction. Arthroscopy 2004;20:899-910. Use of Achilles tendon grafts coated with MSCs for ACL repair in rabbits.MSC-enhanced grafts had significantly higher load-to-failure values than the controlsand the zones of osteointegration more closely resembled that of a normal ACLinsertion when compared to the controls. Soon MH, Hassan A, Hui JP, Goh JH, Lee EH. An analysis of soft tissue allograft anterior cruciate ligament reconstruction in a rabbit model: a short-term study of the use ofmesenchymal stemcells to enhance tendon osteointegration. AmJ Sports Med. 2007 35(6):962-71.
STEM CELLS IN TENDON REPAIRThe use of MSCs is aimed at introducing the cells to a tissue defect or graft therebyincreasing the healing of the graft to bone and the long-term strength and overall function.The current research is still in preclinical stages using animal models but studies showthat MSCs have positive effects in the treatment of tendon or ligament injuries.MSCs suspended in a collagen gel along a resorbable suture scaffold to repair a 1 cmAchilles tendon defect in rabbits.The MSC-treated tendons had a significantly larger cross-sectional area and thecollagen fibers appeared to be better aligned when compared to control specimens. Young RG, Butler DL, Weber W, Caplan AI, Gordon SL, Fink DJ. Use of mesenchymal stem cells in a collagen matrix for Achilles tendon repair. J Orthop Res. 1998 16(4):406-13.
STEM CELLS IN MENISCUS REPAIRSTRATEGY 1 Filling the tear with a piece of meniscus grown in a lab. MSCs are cultured in a chondrogenic medium to promote differentiation into chondrocytes, and then “seeded” onto a scaffold and allowed some time to mature before implantation into the meniscal defect. Results in menisci of rabbits that had hyaluronan/gelatin composite scaffolds inserted into meniscal defects on each leg, one seeded with stem cells, the other left empty. Stem cell-seeded scaffolds produced a statistically significant amount of new fibrocartilage relative to control, and filled in the critical defects. Angele P, Johnstone B, Kujat R, Zellner J, Nerlich M, Goldberg V, et al. Stem cell based tissue engineering for meniscus repair. J Biomed Mater Res A. 2008 85(2):445-55.
STEM CELLS IN MENISCUS REPAIRSTRATEGY 2Bathing damaged menisci in an intra-articular solution of stem cells to aid thehealing process.Isolated and cultured MSCs from a chronic knee pain patient, then injected thosestem cells into his knee joint three times over two weeks.After 3 months, the patient showed statistically significant increases in meniscalvolume on MRI, knee range of motion, and improved knee function as assessed bya validated questionnaire. Centeno CJ, Busse D, Kisiday J, Keohan C, Freeman M, Karli D. Increased Knee Cartilage Volume in Degenerative Joint Disease using Percutaneously Implanted, Autologous Mesenchymal Stem Cells. Pain Physician. 2008 11(3):343-53.
STEM CELLS IN SPINAL CORD INJURYWhat can stem cells do for spinal cordinjuries?Large number of animal studies:Replace the nerve cells that have died as aresult of the injury.Generate new supporting cells that will re-form the insulating nerve sheath (myelin) andstimulate re-growth of damaged nerves.When introduced into the spinal cord shortlyafter injury, stem cells cells may protect thecells at the injury site from further damage,by releasing protective factors.
OLIGODENDROCYTE PROGENITOR CELLSGRNOPC1 - Human embryonic stem cell (hESC)-derived oligodendrocyte progenitor cells.Population of living cells containing precursors to oligodendrocytes, otherwise known asoligodendrocyte progenitor cells (OPC).OligodendrocytesNaturally occurring cells in the nervous system.Produce myelin (insulating layers of cell membrane) that wraps around the axons ofneurons to enable them to conduct electrical impulses.Myelin enables efficient conduction of nerve impulses in the same manner as insulationprevents short circuits in an electrical wire. Without myelin, many of the nerves in thebrain and spinal cord cannot function properly.Produce neurotrophic factors (biologicals that enhance neuronal survival and function)to support the maintenance of nerve cells.Oligodendrocytes are lost in spinal cord injury, resulting in myelin and neuronal loss thatcause paralysis in many patients with spinal cord injuries.
GRNOPC1 - Human embryonic stem cell (hESC)-derivedoligodendrocyte progenitor cells.MENLO PARK, Calif., October 11, 2010 Enrollment of the first patientPhase I study - Primary Goal is to assess the safety and tolerability of GRNOPC1 inpatients with complete American Spinal Injury Association (ASIA) Impairment Scalegrade A thoracic spinal cord injuries.Participants in the study must be newly injured and receive GRNOPC1 within 14 days ofthe injury.
GRNOPC1 Restores Locomotion in Rodent Models of Spinal Cord Injury Journal of Neuroscience, Vol. 25, May 2005.
STEM CELLS IN IVD DEGENERATIONDegeneration of the intervertebral discLeading cause of back pain and associated morbidity.Due to the avascular nature of the IVD, the healing process is slow or absentonce the degeneration starts either from mechanical trauma, aging or idiopathicprocesses.Current conservative and invasive treatment options are aimed at symptomaticrelief.The surgical options available for IVD degeneration are spinal fusion and/ordiscectomy at the affected disc level.However, while these options create short-term solutions, there are frequentcomplications due to alterations made to the biomechanics of the spine.
STEM CELLS IN IVD DEGENERATIONStem cells for the treatment of IVD degeneration.Stop or even reverse the degeneration of the cells within the IVD in order toproduce a matrix with similar or more advanced properties when compared to theoriginal.The current research has made considerable progress with the use of biodegradablematerials to act as scaffolds for the MSCs in order to promote three dimensionalgrowth in animal models.The 3D scaffolds are made of materials such as hyaluronic acid and collagen thatprovide the MSCs with the initial stability and homogeneous distribution required forgrowth in vivo. RisbudMV, Shapiro IM, Vaccaro AR, Albert TJ. Stem cell regeneration of the nucleus pulposus. Spine J. 2004 4(Suppl):S348-53.
PROBLEMS WITH STEM CELLSEthical Debate - Tissue engineering is the first step down a slippery slope towards“playing God”.Research involving pluripotent, embryo-derived stem cells has caused some groupsto claim that this research is conducted at the expense of life.Implanted stem cells from a donor could potentially result in immune reactions withthe recipient such as graft-versus-host disease. Fortunately, as orthopaedic tissueengineering research uses primarily autologous stem cells derived from the eventualhost, major immunological complications are avoided.Risk of secondary solid tumours.Allogenous MSC – Risk of transfer of genetic disease.
ETHICAL DEBATE• Are we trying to play role of GOD?• Is embryo a person?• Will stem cell research encourage embryo destruction and abortions?• Harvesting ES cells destroys the blastocyst . “This is murder”.• “If excess IVF embryos are being discarded anyway, they should be put to good use”.• ES cell research requires human cells. Could create a commercial market for human cells. “This de-values human life”.• “Therapeutic cloning is a slippery slope - it will lead to reproductive cloning”
KEY ETHICAL ISSUES• The blastocyst used in stem cell research is microscopically small and has no nervous system. Does it count as a “person” who has a right to life?• What do various religions say about when personhood begins? Does science have a view on this?• In a society where citizens hold diverse religious views, how can we democratically make humane public policy?
GUIDELINES FOR STEM CELL RESEARCH IN INDIA • Compulsory registration of the existing cell lines to be registered under specific apex bodies in the field • Genetic research dealing with human egg or sperm and genetic engineering and then transfer of human blastocysts will not be allowed. • Research and therapy using fetal/placental stem cell will be allowed • Termination of pregnancy cannot be sought for donating fetal tissue for therapeutic or financial benefits. • All the umbilical cord blood banks should be registered with Drug Controller General of India • Research into human cloning is not to be done
CONCLUSIONStill in preclinical stagesFocus: Mesenchymal stem cell transplantCommon uses Fracture nonunion, AVN Spinal Cord Trauma, IVD Degeneration, Spine fusion ACL ReconstructionCenteno et al:MRI evidence of increased cartilage and meniscus volume in individual subjects
THE NOBEL PRIZE, 1990 E. Donnall ThomasFirst succsessful HSCT in treatment of acute leukemias Thomas ED, Lochte HL, Lu WC, Ferrebee JW. Intravenous infusion of bone marrow in patients receiving radiation and chemotherapy. N. Engl. J. Med. 1957; 257: 491