Growth factors play an essential role in diabetic foot ulcer management. Platelet-derived growth factor (PDGF) is a significant growth factor that is released during wound healing and promotes angiogenesis, fibroblast proliferation, and re-epithelialization. Recombinant human PDGF-BB (rhPDGF-BB) has been shown to accelerate wound healing in diabetic foot ulcers by stimulating cellular processes involved in repair when applied topically according to dosage guidelines.

1. ROLE OF GROWTH FACTORS IN
DIABETIC FOOT ULCER
MANAGEMENT
DR ARUN BAL
PRESIDENT
DIABETIC FOOT SOCIETY OF
INDIA

2. Moist Wound Dressing
• It prevents tissue dehydration
(preserving the viability and proliferative potential).
• Increases breakdown of dead tissue and fibrin
contributing to autolytic debridement.
• Potentiates interaction of growth factors with their
target cells
• Reduces the incidence of infection.
• Associated with less pain.

3. HEMOSTASIS 1 hour
W
O
U
N
D
I
N
G
Platelets
Fibrin
INFLAMMATION days 1 through 7
Proteoglycans
Neutrophils
Macrophages]
Lymphocytes
PROLIFERATION days 2 through 20
Normal wound
healing
Fibroblasts[produce growth factors]
Collagen
Epithelial Cells
Endothelial Cells
REMODELING 1 week to 6 months
Collagen Fibril Cross linking
Scar Maturation
Time from injury

4. Molecular environment of wounds
Healing wounds
High Mitogenic activity
Low inflammatory cytokines
Low proteases
Mitotically competent cells
Chronic Ulcers
Low Mitogenic activity
High inflammatory cytokines
High proteases

6. WOUND BED
PREPARATION
• DYNAMIC & RAPIDLY EVOLVING
CONCEPT
• REDUCES THE WOUND HEALING TIME
• REDUCES HE COST OF THE TREATMENT
• TIME FRAMEWORK
• T:TISSUE MANAGEMENT
• I : INFECTION/INFLAMMATION CONTROL
• M:MOISTURE CONTROL
• E:EPITHELIAL(EDGE)ADVANCEMENT
• DIFFERENCE BETWEEN SHARP & SURGICAL
DEBRIDEMENT

7. GROWTH FACTORS
VITAL FACTOR FOR WOUND HEALING

8. Growth Factors
• Basically signal proteins released from local
tissues that activate target cells to replicate or
migrate.
• Control wound healing by acting in a paracrine,
endocrine or autocrine mode.
• Action of growth factors is complex and
carefully controlled during the normal wound
healing process.
• Growth factors at appropriate concentration are
mitogenic to their target cells

9. Role of various
growth factors
in wound healing

10. Growth factors
Growth factors of significance in wound healing are:
 Platelet Derived Growth Factor (PDGF)
 Vascular Endothelial Growth Factor (VEGF)
 Transforming Growth Factor- β (TGF- β)
 Keratinocyte Growth Factor (KGF)
 Epidermal Growth Factor (EGF)

11. Growth Factors
• Basically signal proteins released from local
tissues that activate target cells to replicate or
migrate.
• Control wound healing by acting in a paracrine,
endocrine or autocrine mode.
• Action of growth factors is complex and
carefully controlled during the normal wound
healing process.
• Growth factors at appropriate concentration are
mitogenic to their target cells

12. Growth Factor Characteristics Location
EGF Mitogenic for epithelial cells Almost all body
(Epidermal Growth Fibroblasts, Endothelial cells fluids Platelets
factor) Angiogenesis
Directs Epithelialisation
Stimulates fibroblast collegenase secretion
Contributes to the scarless repair
KGF Potent mediator for kerotinocytes Fibroblasts
(Keratinocyte Monocyte maturation
growth factor)
PDGF Mitogenic for fibroblasts Endothelial cell
(Platelet derived Potentiates VEGF production Platelets
growth factor) Monocyte maturation Macrophages
FGF Mitogenic for epithelial cells Fibroblasts
(Fibroblast not fibroblasts or endothelial Endothelial
cellgrowth factor) cells
TGF Inhibits mitogenesis of most Macrophages
(Transforming cells Eosinophils
growth factor)
IGF Mitogenic for fibroblasts Fibroblasts
(Insulin Endothelial cell Endothelial cell
growth factor)

13. TGF-β
PDGF-BB
VEGF
TGF-β
VEGF
PDGF-BB
TGF-β
IGF
TGF-βKGF
TGF-α

14. Multiple Growth Factors are Expressed
Temporally in Human Wound Fluid
PDGF
bFGF
VEGF
TGF-β

15. Cause of reduced expression
of growth factors & receptors
in Diabetic Foot Ulcers
Diabetic foot lesion
•Repeated trauma
•Cell detritus/cell-fragments
• Increased & Prolonged
inflammatory response
• Increased invasion of
macrophages & neutrophiles
Increased activation of
macrophages by cytokines and
growth factors
TNF-α; IL-1β
Fibroblasts &
inflammatory cells
Serin-proteases MMPs TIMPs
Degradation of growthgrowth
factors & receptorsfactors & receptors
Diabetologia. 2002 Jul;45(7):1011-6. Epub 2002 May 25
Chronification of Diabetic foot ulcers

16. The only growth factors available
commercially, for the treatment of
diabetic foot ulcers is
1.recombinant human Platelet
Derived Growth Factor (rhPDGF)
2.Epidermal growth Factor

17. Biology
• Platelet Derived Growth Factor is structurally a 25 kDa
protein
• It is released during stages of wound healing by
 Platelets
 Macrophages
 Fibroblasts
 Endothelial cells
 Keratinocytes

18. PDGF and Receptors
• PDGF represents a
family of growth factors
consisting of 2 poly
peptide chains (A & B)
which forms the dimer
(protein pairs).
 PDGF-AA
 PDGF-AB
 PDGF-BB

19. • The PDGF receptor
has a trans-membrane
structure with
extracellular ligand-
binding domains and
intracellular tyrosine
kinase domains.
• Two PDGF receptors
exist, R-α and R-β,
with each possessing
different specificities
for their ligands.

20. • PDGF-BB can activate
any PDGF receptor;
therefore its
therapeutic application
can activate any
configurations of it’s
receptors.
• The proliferation rate
of wound fibroblasts
was higher by PDGF-
BB than PDGF-AB
and -AA.*
* Biochem Biophys Res Commun. 1995 Apr 17;209(2):393-9.

21. rhPDGF-BB
• Recombinant human Platelet Derived Growth Factor
(rhPDGF-BB) is a homo-dimer produced by Recombinant
DNA technology by inserting the human gene of
PDGF-BB in E. coli.
• Can also be produced with Yeast (Saccharomyces
cerevisiae).
• The biological activity of rhPDGF-BB is similar to that of
naturally occurring PDGF.

22. Structure of rhPDGF-BB
Structure of PDGF-BB
Monomers
(depicted in green and blue)

23. Role of PDGF-BB
in wound healing process

24. Expert Opin.Biol Ther. (2002) 2(2):211-218
PDGF is released by Platelets & Macrophages

25. PDGF is released by Fibroblasts

26. * Adapted from 1.Supplement of Podiatry Today, October 2003. 2. Diabetes Care, vol, no.2, no.2, 17-23. 4.Diabetes Care August 1999, 22:8;1,354-60
PDGF is released by Endothelial Cells & Keratinocytes

27. PDGF Action at Cellular Level

28. Angiogenesis with PDGF-BB
1) Binds to its receptor on
vascular endothelial cell.
4) Stimulates endothelial proliferation
2) Inducing production of other
growth factors (VEGF)
3) Activates intracellular signal
transduction pathways
5) Promotes endothelial migration
7) Recruits smooth muscle cells and
pericytes to stabilize the newly formed
vasculature
6) Facilitates vascular tube formation
1
2
3
4
5
6
7

29. Histological Evidence of
Angiogenesis with PDGF
2nd
week
4th
week
Control PDGF

30. Summary of MOA of PDGF-BB
• Chemoattraction for neutrophils, monocytes &
fibroblasts.
• Mitogenic for smooth muscle cells and fibroblasts.
• Stimulates endothelial cells proliferation & migration.
• Promotes vascular tube formation.
• Stimulates epithelialization.
• Induces the release of other growth factors.

31. Toxicology studies*
• Acute & chronic toxicity studies were performed on
various animals showing no abnormal findings.
• Reproductive & teratogenic studies were not performed.
• Mutagenic studies were negative.
• In pharmacokinetic studies the level measured in blood
samples were below the baseline even after repeated
application.
*http://www.fda.gov/cder/biologics/products/becaomj121697.htm

32. Experimental evidence*
• These results suggest that the levels of various growth
factors, particularly PDGF, may be limiting at wound
sites and supplementation of wounds with these factors
can accelerate the rate of new tissue formation.
Acceleration of
new tissue in
growth by PDGF
(in rats). At day
10
*J Clin Invest. 1985 December; 76(6): 2323–2329
Control PDGF

33. 30 & 100 μg/cm2
2.2 μg/cm2
1 & 3 μg
1,10
Dose (daily)
P=0.007
(for 100 μg)
Diabetic
382
Wieman et al.PDGF-BB
P=0.01Diabetic
118
Steed et al.PDGF-BB
N.S.Pressure
45
Mustoe et al.PDGF-BB
N.S.Pressure
20
Robson et al.PDGF-BB
ResultsTarget wound type
No. of subjects
AuthorsGrowth
Factor
Dosage Evaluation
N.S. = Not Significant
Double-blind, placebo controlled trials of PDGF

34. Pharmacokinetics
• rhPDGF-BB 0.01% gel has biological activity similar to
endogenous PDGF and has a high affinity for PDGF-β
receptor
• Daily application of rhPDGF-BB has only negligible systemic
absorption.
• It is present in biological fluid for at least 12 hours in vivo and
24 hours in vitro

35. rhPDGF Experience
Complete healing after 11.5
weeks of GWC and rhPDGF1
After debridement, GWC and
rhPDGF initiated1
1. www.regranex.com

36. Indication
Indicated for the treatment of lower extremity diabetic
neuropathic ulcers* that extend into the subcutaneous
tissue or beyond and have an adequate blood supply,
*(Stage III & Stage IV ulcers IAET Staging
classification)
Good wound care & tight blood glucose control are
very important in rhPDGF-BB therapy.

37. Contra-indications
• rhPDGF-BB gel should not be used in patients with:
 Known hypersensitivity to any component of the
excipients used in the product.
 Known neoplasm(s) at the site(s) of application.

38. Dose calculation
The intended dose is around 7μg /cm² of ulcer per
day for topical application.
(For an average man of around 50kg weight)
Tube Size Formula
7. 5g/15 g tube [Length (cm) X Width (cm) ÷ 4]*
*Greatest length of the ulcer multiplied with greatest width

39. Method of application
• One tube for one patient
• Proper hand wash before application.

40. • Tip of the tube should not come into contact with
the ulcer or any other surface.
• Before each application, the ulcer should be gently
rinsed with saline or water to remove any residual gel
and wound area cleaned.

41. • Applied once a day in a carefully measured quantity
adjusted according to the size of ulcers.
• Calculated dose of gel should be squeezed out onto a
clean, firm, non-absorbable surface (e.g. wax paper) in
a linear fashion.

42. • Use clean application aid (Cotton swab, tongue
depressor, etc )
• Measured quantity of gel should be spread evenly over
the ulcerated area including the margins to yield a thin
continuous layer of ~ 1.5 mm thickness.

43. • Gel should be covered with saline moistened gauze.

44. • Then gel can be gently rinsed off using saline or water
and reapplied.
• Tube should be closed tightly after each use.
• After treatment is completed, any unused gel should be
discarded.

45. (Contd…)
Algorithm for use of platelet derived growth factor (PDGF)
in treatment of diabetic foot ulcer

46. Algorithm for use of platelet derived growth factor (PDGF)
in treatment of diabetic foot ulcer (contd)

47. Epidermal Growth
Factor
• EGF is a single chain
polypeptide
• Comprising of 53
amino acids with
Mol Wt of 6200
Daltons

48. Epidermal Growth Factor
• A cell proliferate growth factor
• Has wide role in cell stimulation
– Cellular components activation
– Has high interaction with plasma
proteins.
• Effective mediator that
– Enhances cell locomotion
– Contractility
– Differentiation
All of which effect wound and
wound healing process.

49. Mode of action
• EGF induces cellular proliferation through the EGF
receptor, which has a tyrosine kinase cytoplasmic
domain - a single transmembrane domain
• Binding of EGF results in EGF receptor activation,
autophosphorylation of the receptor, and tyrosine
phosphorylation of other proteins.
• EGF receptor activates various proteins, ultimately
causing phosphorylation that contributes to
proliferation.

50. EGF Signal Pathways

51. Role of EGF
• Mitogenic for epithelial cells,
Fibroblasts, Endothelial cells
• Angiogenesis
• Directs Epithelialisation
• Stimulates fibroblast collegenase secretion
• Contributes to the scarless repair

52. Role of EGF
• Potent mitogen for many types of cells1
• Shown a greater efficacy in ulcer healing2
• Attracts cells into the wound and stimulates
their proliferation3
• Stimulates the rate of formation of granulation
tissue4
• Enhances wound healing and increases collagen
production5
1. Acta Endocrinol (Copenh). 1990 Sep; 123(3):326-30, 2. Irn J Endocrinol Metab 2003: Vol 5 No 2, 3.
Journal of Trauma-Injury Infection & Critical Care 4(1):159-167, July 1996. 4. J Surg Res. 1987 Oct: 43
(4): 322-8, 5. Biochem J. 1987 Oct 15; 24792:385-8

53. Multi centric, Phase III, Double Blind
• Product Developer:
Bharat Biotech International Ltd
• Centers : 5
• Approved Indications
» Diabetic foot ulcers
» Donor site Skin Grafts
» Ist & IInd Degree Burns

54. Regen -D (Epidermal Growth Factor) Diabetic Foot Ulcer
Trial summary
• Total no. of patients - 57
– Group 1 (EGF) - 29
– Group 2 (Control) - 28
Group 1 Group 2 p value
No. of patients 29 28
M / F 22 / 7 20 / 8
Mean age (in yrs) 58 ± 1.9 59 ± 2.0
Ulcer size (in cm2
) 13.3 ± 3.1 12.5± 2.2
No of Healed cases
at 10 weeks
20 6
No of Healed cases
at 15 weeks
25 14 < 0.01
Mean healing time
(days)
56.8 ± 4.7 81± 4.4 < 0.01

55. Week, w
Percentageofpatientscuredbyweekw
282420161284
100
80
60
40
20
0
Figure-5: Efficacy of Regen-D Gel
Cont rol
Test
The healing takes place before the end of the 8th
week in 50% of the patients
under test; and it takes nearly 15 weeks to cure 50% of the patients under
control.

56. Case no 8 : Healed in 8 weeks
Source : Dr.Vijay Viswhanathan , MVJ center for Diabetes, Chennai
1st
stage II nd stage
III rd stage Final stage
DFU Indication

57. GROWTH FACTORS
• NEED TO USE SELECTIVELY
• NOT USEFUL IN PVD
• SHOULD BE USED ONLY WITH NORMAL
SALINE
• NEED TO BE USED DAILY
• SHOULD BE USED ONLY IF WOUND
HEALING IS DELAYED BEYOND 3 WEEKS
• STRICT OFF LOADING,GLYCEMIC
CONTROL,NUTRITIONAL CONTROL IS
IMPORTANT
• NOT USEFUL WITH SLOUGH,DISCHARGE &
INFECTION

58. PDGF IN DIABETIC FOOTPDGF IN DIABETIC FOOT
WOUNDSWOUNDS
10DAYS AFTER PDGF
USE
15 DAYS AFTER
PDGF USE

60. 25 DAYS AFTER PDGF

62. 17 DAYS AFTER PDGF USE

63. BEFORE TREATMENT

64. 8 DAYS AFTER PDGF

65. 15 DAYS AFTER PDGF

66. FOOT ULCER
FORMATION IS
BEGINNING OF THE
END

67. THANK YOUTHANK YOU