Dr. Vijay Viswanathan, M.D, Ph.D, MNAMS Joint Director Diabetes Research Centre &

1. Derangement of wound healing in Diabetic Neuropathy Dr. Vijay Viswanathan, M.D, Ph.D, MNAMS Joint Director Diabetes Research Centre & M. V. Hospital for Diabetes Chennai. WHO Collaborating Centre for Research, Education & Training in diabetes

2. Factors found in Diabetes and Impaired wound healing Peripheral neuropathy • Loss of protective sensation • Autonomic dysfunction • Impaired neuroinflammatory reflex Wound hypoxia • Macrovascular disease • Microvascular disease • Capillary loss • Microvascular endothelial dysfunction

3. Factors found in Diabetes and Impaired wound healing Abnormal cellular pathways • Chemotaxis • Fibroblast responsiveness Excess inflammation • Oxidative stress • Endothelial dysfunction and impaired nitric oxide signaling • Increased inflammatory cytokine expression • Advanced glycosylation end products (AGEs) and receptors (RAGE) Deficient precursor cells

4. Phases of normal wound healing Scar Maturation Collagen Fibril Crosslinking REMODELING 1 week to 6 months Endothelial Cells WOUNDING Epithelial Cells Collagen Fibroblasts[produce growth factors] PROLIFERATION days 2 through 20 Lymphocytes Macrophages] Neutrophils INFLAMMATION days 1 through 7 Proteoglycans Fibrin Platelets HEMOSTASIS 1 hour Time from injury

5. Prolonged inflammatory reaction Due to (1) Bacterial contamination (2) Recurrent painless tissue trauma  in no. of neutrophils in the wound These secrete proinflammatory cytokines (TNF - ), Interleukin (IL - 1) These stimulate synthesis of proteases (MMP’S) Degrade matrix proteins & growth factors Disruption in wound healing What happens in diabetes mellitus to wound healing

6. Changes at the molecular level in diabetes and their potential interrelationships leading to alterations of macromolecular functions, which contribute to poor healing and ulcer formation (a) Diminished neuroinflammatory signalling  NGF  Nerve content  Substance P  Neuroinflammatory signalling  Glucose  NEP activity

7. Changes at the molecular level in diabetes and their potential interrelationships leading to alterations of macromolecular functions, which contribute to poor healing and ulcer formation (b) Pathways of oxygen free radical production which in turn could damage DNA of cells involved in wound healing  Glucose  Glycation  AGE  Activity antioxidant enzymes  Oxygen free radicals Damage cellular DNA  GSH  Arginase and NOS activities

8. Changes at the molecular level in diabetes and their potential interrelationships leading to alterations of macromolecular functions, which contribute to poor healing and ulcer formation (c) Decreased angiogenesis  TGF - 1  IGF - 1  TGF - 1  TGF - 1  NGF  NGF  NOS activity  NO  VEGF  Angiogenesis  KGF  bFGF  NOS activity  KGF  NO  IL - 6  IL - 6  bFGF  IL - 6

9. Changes at the molecular level in diabetes and their potential interrelationships leading to alterations of macromolecular functions, which contribute to poor healing and ulcer formation (d) Diminished ECM deposition  TGF - 1  IGF - 1  GAG synthesis  Collagen synthesis  NO  ECM deposition  Neutrophil elastase and cathepsin G activities  TIMP  MMP activity  TNF  TGF - 1

10. Imbalances in the molecular environments of acute healing wounds and chronic non-healing wounds 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 Senescent cells

11. INFLAMMATION A VISCIOUS CYCLE IN DELAYED WOUND HEALING IN DIABETES Vijay Viswanathan *, Shiny John Vairamon **, A. Ramachandran *, C. Snehalatha * and Mary Babu ** * : Diabetes Research Centre, Royapuram, Chennai – 13, India ** : Biomaterial division, Central Leather Research Institute, Adyar, Chennai – 20 , India

12. Aim To study the role of the inflammatory status in the delayed wound healing of diabetic patients

13. Subjects: Study groups were: • Group 1: Non-diabetic controls (n=10) • Group 2: Patients with diabetes (n=10) • Group 3: Diabetic neuropaths with foot ulceration [non infected] (n=10) • Group 4: Diabetic neuropaths with foot ulceration [infected] (n=10) • Group 5: Diabetic patients with neuroischemia and foot ulceration [non infected] (n=10) • Group 6: Diabetic patients with neuroischemia and foot ulceration [infected] (n=10)

14. Matrix – degrading metalloproteinases (MMP) • Physiologic mediators of matrix degradation • Zinc dependent endopeptidases, which are capable of collectively degrading all kinds of extracellular matrix proteins • Play an important role in tissue remodeling Matrix – degrading metalloproteinases (MMP) Collagenases Gelatinases Stromelysins Gelatinase B (MMP – 9) Gelatinase A (MMP – 2) Product of other cell types, including neutrophils and keratinocytes

15. Methods • Neuropathy was diagnosed ad VPT>25V by biothesiometer • Peripheral vascular disease was diagnosed as ankle brachial index (ABI)<0.8 • The expression of Matrix Metalloprotinases in tissue homogenates (MMP-9) of diabetic foot ulcers and also in the serum of the subjects (MMP-2) by Zymogram & Western Blot

19. Results • MMP-9 active form was expressed in the tissue homogenate of diabetic patients both in neuropathy & neuroischemic with infective foot ulcer and not in diabetic patients with callus • MMP-2 active form was expressed more in the serum of diabetic patients both in neuropathy and neuroischemic with infective foot ulceration.

20. The over expression of matrix metalloprotinases in the wound tissue contribute to the delayed wound healing.

21. Platelet – derived growth factor (PDGF) • PDGF plays a role in most phases of wound healing • displaying a variety of activities including as a chemoattractant • stimulating cells to secrete growth factors and inducing the production of several matrix molecules. [Heldin CH et al., Physiol Rev 1999; 79: 1283 – 1316] [Goldman R et al., Adv Skin Wound Care 2004; 17: 24 - 35] • Lack of PDGF protein was found in chronic wound fluid from diabetic patients. [Castronuovo JJ Jr et al., Am J Surg 1998; 176: 61S – 67S] • Addition of PDGF has been shown to enhance wound healing and increase wound – breaking strength. [Pierce GF et al., J Cell Biol 1989; 109: 429 - 440]

22. Components of Optimal Wound Care • A comprehensive, standardisedwound care regimen • Correct underlying condition • Control infection • Address ischaemia • Correct structural defects • Adequate glycaemic control for diabetic patients • Adequate debridement • Appropriate topical management (eg growth factors)

23. Wound dressings and treatments

24. Today there are more than 2000 wound care products available, most of which are different varieties of dressings (Cohen IK, 1998) . • Most modern dressings contain materials that are highly absorbent, such as alginates or foam. The list of modern wound dressings available is long and impressive; some types include : Alginates Composites Exudate absorbersFoams GauzesHydrocolloids HydrogelsSkin Sealants Transparent Films (Mulder GD, Haberer PA, Jeter KF, 1998)

25. Use of Biatin Silver in different types of Diabetic Foot Wounds Why add Silver? • The antimicrobial of silver (or more accurately silver ions, Ag+) were exploited long before microbes were discovered. • They selectively bind to thiol groups, which are widely distributed in bacterial cell wall proteins • Also bind to bacterial DNA [Lansdown, 2002] • The silver added to advanced wound management products (AWMP) is added in forms designed to make the cations more readily available.

26. Name : Mrs. Pusphammal Age: 61 years Sex: Female Diabetic for 10 years ; HbA1c: 12.2%; H/O pinprick over right heel – 3 wks back; came with a right heel abscess; discharging pus;; X-ray foot showed osteomyelitis of right calcaneum Urea / Creatinine / Neuropathy: Normal Patient underwent debridement and bone curettage on 6/3/06 ; Normal vascularity Started on Biatain Ag dressing from 1st Post operative day Came for review on 30/3/06 and 5/4/06 Wound looks clean; size has decreased ; granulations have started covering calcaneum.

27. Name : Mr. Chinnaiah.P Age: 68 years Sex: Male Diabetic for 6 years ; HbA1c: 6.5%; Admitted with left charcot foot with midfoot collapse with plantar midfoot ulcer 5 x 5cm with a cavity underneath with cellulitis leg. Ulcer debrided on 5/3/06 ; OM of underlying bones + ; infected bones curetted ; good vascularity Started on Biatain dressing from 7/3/06 CAD / Nephropathy (S. Creat : 4.8) ; Neuropathy + Came for review on 27/3/06 Ulcer has decreased in size ; some maceration present.

28. Hippocrates said that: “Healing is a matter of time, but it is sometimes also a matter of opportunity”. Hippocrates (460 BC – 377 BC), Precepts. This is very relevant concept when applied to the diabetic foot