The document discusses how gene therapy can be used to better understand and treat musculoskeletal disorders and injuries by promoting tissue regeneration through localized delivery of growth factors and cytokines. It outlines how viral and non-viral vectors can be used to introduce therapeutic genes into tissues to accelerate healing and reduce recovery time for conditions like fractures, osteoarthritis, tendon injuries, and muscular dystrophy.

2.  Mechanical stabilization & Biomechanical
analysis—Alone !!???
 Biology of soft tissue and bone healing
needed for good outcome and success.
 Eg: RA– dependent on action of growth
factors, cytokines antigen presentations
and protein interactions

3.  OA– molecular biological, immunological &
biochemical aspects play key role
 Other disorders– Osteogenesis imperfecta,
DMD – today’s treatment – only
symptomatic
 Genetic defect and biological effect to be
understood to provide a curative treatment

4.  Elegant technique
 Sustained local delivery of therapeutic growth
factors/cytokines using
 Viral/nonviral delivery vehicles(vectors)
 Genetic information– cDNA encoding the
protein of interest is inserted into living cell
 Potential to express the protein

5.  Soft tissues Diff capacities to heal foll injuries
 Healing by formation of scar– decreased
mechanical stress than original tissues
 Genes for specific growth factors
 Introduced into injured tissue

6.  Directly– injected into tissue & inserts gene
into surrounding cells
 Indirectly– muscle/skin biopsy- cultured &
vector introduced into cells
 Viral– transduction
 Non viral-- transfection

7.  Replication deficient retrovirus
 Adenovirus
 Adeno associated virus
 Herpes virus
 Lentivirus

8.  Liposomes
 DNA-protein conjugates
 DNA-protein defective virus conjugates

9.  Therapies that will replace, repair and
promote tissue regeneration
 # healing involves many regenerative
mechanisms.
 BMP -- key molecule

10.  Impact of #-- Several members of BMP
induced & activated
 Synth by callus forming cells near # site
 BMP Network–
 Noggin
 Sonic hedgehog(shh)
 Hepatocyte growth factor(HGF)
 Vascular Endothelial Growth Factor(VEGF)

11.  Major driving force for new treatment
techniques—
 Reduction of recovery time
 Least invasive

12.  Current modalities—
 Use of tissue graft, cell
transplantations, artificial scaffolding.
 Short half life and inherent instability of
proteins
 Requires high and multiple doses of
proteins

13.  Sustained release of biological agent at
therapeutic levels
 By transfer of gene encoding the therapeutic
agent to the cells of the afflicted tissue or
 By implanting cells that have been previously
genetically modified

14.  Accelerated and enhanced Musculoskeletal
tissue (Bone, ligament, tendon, cartilage)
regeneration
 Inhibit disease progression

15.  Bone and soft tissue healing
 Degenerative(OA,RA,disc)
 Congenital (OI,DMD,ED)
 Tumors

16.  Growth factors– BMP
 Accelerate healing of segmental defects
 BMP-7-mediated ex vivo gene transfer based
on Mesenchymal Stem Cells may accelerate
callus formation in distraction osteogenesis
and facilitate consolidation.
 Hu J - J Orthop Res - 01-FEB-2007; 25(2):
241-51

17.  Delayed administration of adenoviral BMP-
2 vector improves the formation of bone in
osseous defects
 achieve radiological union, repair tissue
with enhanced mineralization and greater
mechanical strength
 Betz OB - Gene Ther - 01-JUL-2007;
14(13): 1039-44

18.  Recombinant BMP-2 used for spinal fusion
successfully in clinical trials
 Large dose needed for adequate bone
repair
 Comparison of lentiviral and adenoviral
gene therapy for spinal fusion in rats.
Miyazaki M - Spine - 1-JUN-2008;
33(13): 1410-7

19.  Reconstructed ACL grafts undergo
remodelling; no regeneration
 With Gene Therapy
 Regenerate ACL from tendon graft

20.  Use of rhBMP-2 or rhBMP-7 in an
injectable calcium phosphate matrix in an
intra-articular model of rabbit ACL
reconstruction improved tendon-to-bone
healing, based on histologic analysis and
biomechanical testing.
 Clinics in Sports Medicine - Volume
26, Issue 4 (October 2007)

21.  Adenovirus mediated Gene therapy with
BMP-14 and BMP-12 increased tendon
tensile strength in a rat model of Achilles
tendon injury. –
 Bolt P - J Bone Joint Surg Am - 01-JUN-
2007; 89(6): 1315-20
 Majewski M - Gene Ther - 01-AUG-2008;
15(16): 1139-46

22.  Construction of eukaryotic expression
plasmid of bFGF gene in rats and its
expression in tenocytes.
 – increase in expression of type I and III
collagen mRNA--repair of tendons and
ligaments.
 Feng Y - J Huazhong Univ Sci Technolog
Med Sci - 01-FEB-2007; 27(1): 27-30

23.  Articular cartilage:
 Highly organised
 Avascular
 Low healing capacity
 Degeneration/loss of articular surface—
challenging problem

24.  regulatory molecules that augment the
reparative activities of the cells, inhibit the
cells' degradative activities-- include
 insulin-like growth factor I,
 fibroblast growth factor 2,
 bone morphogenetic proteins 2, 4, and 7,
and
 interleukin-1 receptor antagonist.

25.  Gene transfer into articular cartilage and
synovial lining cells
 protect existing cartilage and
 build new cartilage.
 Gene therapy for articular cartilage repair.
Trippel S - Proc Inst Mech Eng [H] - 01-
JUL-2007; 221(5): 451-9

26.  Articular chondrocytes are receptive to
transduction
 AAV vector mediated TGFbeta1-
overexpression stimulates cartilage
anabolism.

27.  Studies
 Viral vectors used to transfer genes– IL-
1Ra, IGF-1 and GFAT gene to increase the
capacity of joint tissues to synthesize
glucosamine.
 achieve long-term relief

28.  Amelioration of osteoarthritis by intra-
articular hyaluronan synthase 2 gene
therapy.
 - Zhang DW - Med Hypotheses - 01-JAN-
2007; 69(5): 1111-3

29.  Attempts to block
 Primary inflammatory mediators-- IL-1
 Redirection of primary immune cells like Th-1
and Th-2 lymphocytes

30.  new targets for gene therapy in the
intervertebral disc–
 TGF-beta1, TIMP-1, and LMP-1
 Gene therapy for the treatment of
degenerative disk disease.
Hubert MG - J Am Acad Orthop Surg - 01-
JUN-2008; 16(6): 312-9

31.  Nucleus pulposus cellular longevity by
telomerase gene therapy. - Chung SA -
Spine - 15-MAY-2007; 32(11): 1188-96
 Telomerase can extend the cellular
lifespan of nucleus pulposus cells
 prolong the production of extracellular
matrix

32.  The RANKL system
 therapeutic target in treatment of aseptic
periprosthetic loosening.
 gene transfer using an AAV vector has
protective effects against orthopaedic wear
debris-induced bone loss.

33.  Adenovirus-mediated transfer of siRNA
against Runx2/Cbfa1 inhibits the formation
of heterotopic ossification induced by BMP4
(in animal model.)
 Lin L - Biochem Biophys Res Commun - 20-
OCT-2006; 349(2): 564-72

34. CONGENITAL
 mutations in cartilage oligomeric matrix
protein (COMP),
(synthesized by chondrocytes)
 causes two skeletal dysplasias:
 multiple epiphyseal dysplasia (MED/EDM1),
 pseudoachondroplasia (PSACH), a
dwarfing condition

35.  Detailed knowledge of pathology helpful in
future treatment with gene therapy
 Expression of mutant cartilage
oligomeric matrix protein in human
chondrocytes induces the
pseudoachondroplasia phenotype.
Merritt TM - J Orthop Res - 01-APR-2006;
24(4): 700-7

36.  Lentivirus mediated Heme Oxygenase-1 gene
transfer enhances myogenic precursor cell
survival after autologous transplantation in
pig skeletal muscle.
Laumonier T - Mol Ther - 01-FEB-2008;
16(2): 404-10

37.  gene therapy may achieve induction of
tumour necrosis and
 increased tumour sensitivity to chemotherapy

38.  BMP-2 levels diminished after
Perioperative radiation therapy in M/sk
sarcoma
 Gene therapy to enhance allograft
incorporation after host tissue irradiation.
- Santoni BG - Clin Orthop Relat Res - 01-
AUG-2008; 466(8): 1921-9

39.  Attenuated Salmonella typhimurium with
IL-2 gene reduces pulmonary metastases
in murine osteosarcoma.
 - Sorenson BS - Clin Orthop Relat Res -
01-JUN-2008; 466(6): 1285-91

40.  Pigment epithelium-derived factor
overexpression inhibits orthotopic
osteosarcoma growth, angiogenesis and
metastasis.
 Done in rats and humans- promising
approach
 Ek ET - Cancer Gene Ther - 01-JUL-2007;
14(7): 616-26

41.  Novel cytosine deaminase fusion gene
enhances the effect of radiation on breast
cancer in bone by reducing tumor burden,
osteolysis, and skeletal fracture.
 - Goblirsch M - Clin Cancer Res - 15-
MAY-2006; 12(10): 3168-76

42.  Limited understanding of
 Biochemical properties &
 Molecular mechanisms of connective tissue
 Gene Therapy- one of the most advanced
and exciting concepts
 For a better & less invasive treatment
options