A 9 YearA 9 Year Clinical Experience with Clinical Experience with Kelo-cote Kelo-cote ®®

The Role of Topical Silicone In Wound The Role of Topical Silicone In Wound HealingHealing

Rex Moulton-Barrett, MDRex Moulton-Barrett, MD

Plastic and Reconstructive SurgeryPlastic and Reconstructive Surgery

Oakland, CaliforniaOakland, California

Not all wounds are created Not all wounds are created equallyequally

• Fresh surgical: sharp edges, tensionless epidermis, layered dermal repairFresh surgical: sharp edges, tensionless epidermis, layered dermal repair

• Traumatized tissue: crushed irregular edges, tensionTraumatized tissue: crushed irregular edges, tension

• Thermal and chemical burns: basal layer and dermis may be absentThermal and chemical burns: basal layer and dermis may be absent

• Post-scar ( hypertrophic/keloid ) excision: tendency to recurPost-scar ( hypertrophic/keloid ) excision: tendency to recur

• Scar prone locations: chin to xiphoid, intra-mucosalScar prone locations: chin to xiphoid, intra-mucosal

• Scar prone races: related to Fitzpatrick skin types: tan easily=scar easilyScar prone races: related to Fitzpatrick skin types: tan easily=scar easily

Epidermis: 40 - 150 microns

Dermis: 140 - 400 microns

E & D: 180 >/= 550 microns

Choices In Topical TherapyChoices In Topical Therapy Dry Wounds Dry Wounds

• TapesTapes: control tension, shear through surface protection, : control tension, shear through surface protection, hydrationhydration

• Oil based antibiotic ointmentsOil based antibiotic ointments: Polymyxin, Bacitracin, : Polymyxin, Bacitracin, Bactroban, NeosporinBactroban, Neosporin

• Skin substitutesSkin substitutes: Biobrane, Alloderm: Biobrane, Alloderm• Silicone gel: Silicone gel: Kelo-cote, Scarfade, Mederma Kelo-cote, Scarfade, Mederma • Silicone gel sheetingSilicone gel sheeting: Cica-care, Epiform, Mepilex, : Cica-care, Epiform, Mepilex,

Mepitel, SilgelMepitel, Silgel• Collagens: Clayton ChagallCollagens: Clayton Chagall• Tissue adhesivesTissue adhesives: cyanoacrylate-Dermabond, Epiglu, Indemil, : cyanoacrylate-Dermabond, Epiglu, Indemil,

LiquibandLiquiband• Barrier filmsBarrier films: fast drying carrier solvent: Cavillon, Comfeel, : fast drying carrier solvent: Cavillon, Comfeel,

SuperskinSuperskin

Choices In Topical TherapyChoices In Topical Therapy Wet Wounds Wet Wounds

• Silver dressingsSilver dressings: Acticoat, Actisorb, Avance, Flamazine: Acticoat, Actisorb, Avance, Flamazine• FoamsFoams: absorptive for exudates-Allevyn, Flexipore: absorptive for exudates-Allevyn, Flexipore• AlginatesAlginates: seaweed based very absorptive- Meligisorb, Algisite, Sorbsan: seaweed based very absorptive- Meligisorb, Algisite, Sorbsan• HydrogelsHydrogels: >70% water,minimally absorptive- Aquaform, Intrasite, Nu-: >70% water,minimally absorptive- Aquaform, Intrasite, Nu-

GelGel• HydrocolloidsHydrocolloids: semi-permaeable-Aquacel, Cutinova: semi-permaeable-Aquacel, Cutinova• Vapour permaeable filmsVapour permaeable films: semi-permeable, fluid accululates-Tegaderm: semi-permeable, fluid accululates-Tegaderm• Low-Adherance DressingsLow-Adherance Dressings: Telfa, Medipore, Cutilin, Xeroform: Telfa, Medipore, Cutilin, Xeroform• Multi-layer bandagesMulti-layer bandages: useful for venous ulceration- Profore: useful for venous ulceration- Profore

Components of Normal Wound Components of Normal Wound HealingHealing

•Coagulation Coagulation processprocess

•Inflammatory Inflammatory processprocess

•Migratory/ Migratory/ ProliferativeProliferativeprocessprocess

•Remodeling Remodeling processprocessInjury: hours / days weeks

A) Immediate to 2-5 days B) Hemostasis : Vasoconstriction , Platelet

aggregation , Thromboplastin clot C) Inflammation: Vasodilation , Phagocytosis

A) 2 days to 3 weeks B) Granulation: Fibroblasts lay collagen, Fills & new capillaries C) Contraction: Wound edges pull together to reduce defect D) Epithelialization: Crosses moist surface up to 3 cm

A) 3 weeks to 2 years B) New collagen forms which increases tensile strength C) Scar tissue is only 80 percent as strong as original tissue

Biochemical DifferencesBiochemical Differences

HealingHealing wounds wounds ChronicChronic wounds wounds

• cell mitosiscell mitosis• pro-inflammatory cytokinespro-inflammatory cytokines• matrix metalloproteinasesmatrix metalloproteinases• growth factorsgrowth factors• cells capable of respondingcells capable of responding to healing signalsto healing signals

TIMETIME Principles of Wound Bed Principles of Wound Bed PreparationPreparation Wound bed preparation accelerates healingWound bed preparation accelerates healing

Tissue non viable or deficient

Infection or inflammation

Moisture imbalance

Edge of wound non advancing or undermined

Defective matrix and cell debris

High bacterial counts or prolonged inflammation

Desiccation or excess fluid

Non-migrating keratinocytesNon-responsive wound cells

Debridement

Antimicrobials

Dressings compression

Biological agents Adjunct Therapies Debridement

Restore wound base and ECM proteins

Low bacterial counts and controlled inflammation

Restore cell migration, maceration avoided

Stimulate keratinocyte migration

Debridement MethodsDebridement Methods

• Surgical: exciseSurgical: excise• Mechanical: adherence, sheer, irrigateMechanical: adherence, sheer, irrigate• Autolytic: topicalAutolytic: topical• Enzymatic: topicalEnzymatic: topical• Biological: topicalBiological: topical

Autolytic DebridementAutolytic Debridement

•The process by which the The process by which the wound bed utilizes phagocytic wound bed utilizes phagocytic cells and proteolytic enzymes cells and proteolytic enzymes

to remove debristo remove debris

•This process can be promoted This process can be promoted and enhanced by maintaining and enhanced by maintaining a moist wound environmenta moist wound environment

Autolytic Debridement Autolytic Debridement ConsiderationsConsiderations

•Less aggressiveLess aggressive•SlowerSlower•Easy to performEasy to perform•Little or no discomfortLittle or no discomfort•Performed in any settingPerformed in any setting•Contraindication: infectionContraindication: infection

Enzymatic DebridementEnzymatic Debridement

•The use of topically applied The use of topically applied chemical agents to stimulate chemical agents to stimulate the breakdown of necrotic the breakdown of necrotic tissuetissue

•Common Topical AgentsCommon Topical Agents– Papain-UreaPapain-Urea– Papain-Urea-Papain-Urea-

ChlorophyllinChlorophyllin– CollagenaseCollagenase

Enzymatic DebridementEnzymatic Debridement

Collagenase• Derived from Clostridium Hystoliticum

• Highly specific for peptide sequence found in collagen

• Less aggressive debridement

• Site of action – collagen fibers anchoring necrotic tissue to the wound bed

10Harper (1972) 11Boxer (1969) 12Varma (1973)

Enzymatic DebridementEnzymatic Debridement

Papain-UreaPapain-Urea• Proteolytic enzyme derived papayaProteolytic enzyme derived papaya66

• Urea is added as a denaturantUrea is added as a denaturant66

• Site of action – cysteine residues on Site of action – cysteine residues on proteinprotein88

6Falabella (1998) 8 Sherry and Fletcher (1962)

Enzymatic Debridement Enzymatic Debridement ConsiderationsConsiderations

• Should be painlessShould be painless• Less traumatic thanLess traumatic than surgical or surgical or

mechanicalmechanical debridementdebridement• Easy dressing changeEasy dressing change• Observe caution withObserve caution with infected woundsinfected wounds

*Agency for Healthcare Research and Quality (1994)

•Consider for individuals Consider for individuals who:who:

– Cannot tolerate Cannot tolerate surgerysurgery

– long-term-care facilitylong-term-care facility

– home care*home care*

The right method is a clinical decision that requires judgment

Autolytic Collagenase Papain-Urea-Chlorophyllin

Bacterial BalanceBacterial Balance

• Intact skin is a physical barrierIntact skin is a physical barrier• Skin secretes fatty acids and Skin secretes fatty acids and antibacterialantibacterial

polypeptidespolypeptides• Normal flora prevent pathogenic floraNormal flora prevent pathogenic flora from establishingfrom establishing

13Robson (1997) 14Dow (2001)

Bacterial BurdenBacterial Burden

• Tissue bacterial levels Tissue bacterial levels > 10> 105/gram5/gram have consistently resulted in have consistently resulted in impaired healing causing:impaired healing causing:

• Metabolic loadMetabolic load• Produces endotoxins and proteasesProduces endotoxins and proteases

Efficacy of traditional topical Efficacy of traditional topical antibioticsantibiotics

• Leyden & Kligman, 1979Leyden & Kligman, 1979: Neomycin contact sensitivity < 1% skin : Neomycin contact sensitivity < 1% skin testing testing

• Booth, etal,1994Booth, etal,1994:: Minimum Inhibitory Concentration mg/LMinimum Inhibitory Concentration mg/L

Bacteria A:Neomycin Bacteria A:Neomycin B:Bacitracin C:Polymyxin B (TAO): A+B+C B:Bacitracin C:Polymyxin B (TAO): A+B+CStaph AureusStaph Aureus 1 1 5454 6161 synergysynergyPseudomonas aerug.Pseudomonas aerug. 32 32 >6917 >6917 8 8 synergysynergyEnteric bacillus 8 >6917 1 Enteric bacillus 8 >6917 1 synergysynergy

• Dire, et al, 1995Dire, et al, 1995: Uncomplicated sutured soft tissue trauma wounds: Uncomplicated sutured soft tissue trauma wounds Topical Agent Infection RateTopical Agent Infection RateBacitracin ZincBacitracin Zinc 5.5%5.5%TAOTAO 4.5%4.5%PetroleumPetroleum 17.6%17.6%

3 3 ““RulesRules”” for Topical Antimicrobial for Topical Antimicrobial Agents ?Agents ?•Do not useDo not use antibiotics that are used antibiotics that are used systemicsystemically – ability to ally – ability to breed resistant organisms (topical breed resistant organisms (topical gentamicingentamicin, tobramycin), tobramycin)

•Do not useDo not use agents that are common agents that are common allergensallergens (neomycin, (neomycin, gentamicin, amikacin, tobramycin, gentamicin, amikacin, tobramycin, bacitracinbacitracin, lanolin), lanolin)

•Do not use agentsDo not use agents that have high that have high cellular toxicitycellular toxicity in healable in healable wounds (povidone iodine, chlorhexidine, wounds (povidone iodine, chlorhexidine, hydrogen peroxidehydrogen peroxide))

22Sibbald 2003

Topical Antimicrobials: Topical Antimicrobials: SilverSilver•Centuries of useCenturies of use•Cytotoxicity associated with carriers not Cytotoxicity associated with carriers not

silver - ex. Silver silver - ex. Silver nitratenitrate, Silver , Silver sulfasulfadiazinediazine•Traditional delivery required repeated Traditional delivery required repeated

applications due to binding with chlorine and applications due to binding with chlorine and proteins proteins

•New silver dressings allow for continued New silver dressings allow for continued silver release in to the dressing - up to 7 dayssilver release in to the dressing - up to 7 days

17Demling and DeSanti (2001)

Why Silver for Wound Bed Why Silver for Wound Bed Preparation?Preparation?• Broad spectrum antimicrobial: yeasts, molds & Broad spectrum antimicrobial: yeasts, molds & bacteria, including MRSA bacteria, including MRSA

• Kills microbes on contact: inhibition cellular respirationKills microbes on contact: inhibition cellular respiration denatures nucleic acids denatures nucleic acids alters cell membrane permeabilityalters cell membrane permeability

• Does not induce resistance: if used at adequate levelsDoes not induce resistance: if used at adequate levels

• Low mammalian cell toxicityLow mammalian cell toxicity

Nanocrystalline SilverNanocrystalline Silver

•Decreased size of silver Decreased size of silver particles leads to increased particles leads to increased proportion of surface atoms proportion of surface atoms

•The nanocrystalline structure The nanocrystalline structure is responsible for the rapid and is responsible for the rapid and long lasting actionlong lasting action1515

17Demling and DeSanti (2001)

Magnification of normal Silver

Magnification of Nanocrystalline Silver (< 1 micron)

Evaluating Silver ProductsEvaluating Silver Products

• Minimum bactericidal concentration Minimum bactericidal concentration (MBC) (MBC) - amount of antimicrobial - amount of antimicrobial agentagent

required to kill a given microbe required to kill a given microbe MBC is represented by a log reduction of 3MBC is represented by a log reduction of 3

Stratton et al (1991)Stratton et al (1991) – The silver required varies from 5ppm - 50+ The silver required varies from 5ppm - 50+

ppm for clinically relevant microbes ppm for clinically relevant microbes Yin et al (1999) & Hall (1987) Yin et al (1999) & Hall (1987)

– MBC of silver for MRSA = 60.5 ppmMBC of silver for MRSA = 60.5 ppm Calculated from Maple et al (1992)Calculated from Maple et al (1992)

Moist Wound Moist Wound EnvironmentEnvironment

Additional benefitsAdditional benefits

•Faster healing Faster healing

•Capacity for autolysisCapacity for autolysis

•Decreased rates of Decreased rates of infection infection

•Reduced wound traumaReduced wound trauma

•Decreased painDecreased pain

•Fewer dressing changesFewer dressing changes

•Cost effectiveCost effective

• DifferentDifferent from acute wound from acute wound

• ImbalanceImbalance of growth factors and of growth factors andpro-inflammatory cytokinespro-inflammatory cytokines

• Excessively high levels of Excessively high levels of proteasesproteases

• DegradesDegrades ECM and selectively ECM and selectively inhibitsinhibits proliferating proliferating cells cells

21Enoch and Harding, 2003

Exudate from a Chronic Wound

Managing Moisture Managing Moisture ImbalanceImbalance

• FilmsFilms

• HydrogelHydrogel

• HydrocolloidHydrocolloid

• AlginateAlginate

• FoamsFoams

• Specialty AbsorbentSpecialty Absorbent

• Suction VacSuction Vac

• Exudate amountExudate amountNone Small Moderate Large

Suction Vac TherapySuction Vac Therapy

Management of open woundsManagement of open wounds

• increases granulation rate> 5xincreases granulation rate> 5x’’ss

• success depends on pore size, -125mmHgsuccess depends on pore size, -125mmHg

• reduces wound volumereduces wound volume

• requires changing every 2 daysrequires changing every 2 days

• vascular ingrowth and vascular ingrowth and healing appear to be due cell deformationhealing appear to be due cell deformation

• early epithelial cells lack rete pegs and early epithelial cells lack rete pegs and are easily strained to 5-20%, are easily strained to 5-20%, postulated mechanismpostulated mechanism Saxena, etal, 2004: PRS 114(5)Saxena, etal, 2004: PRS 114(5)

Modern Scar Concepts (1)Modern Scar Concepts (1)

• New keratinocytes lack rete pegs, are fragile, New keratinocytes lack rete pegs, are fragile, deformabledeformable

and produce many fibrotic growth factorsand produce many fibrotic growth factors

• Fibroblasts within the injury zone are more sensitive Fibroblasts within the injury zone are more sensitive to these and other growth factorsto these and other growth factors

• Sulphated side chains develop from chondroitin Sulphated side chains develop from chondroitin produced from these fibroblastsproduced from these fibroblasts

• The side chains cause water binding and The side chains cause water binding and subsequent scar rigiditysubsequent scar rigidity

Modern Scar Concepts (2)Modern Scar Concepts (2)CollagenesisCollagenesis - Deposition - - Deposition - ResorptionResorption

CollagenesisCollagenesis• Scar volume is dependent on the volume of collagenScar volume is dependent on the volume of collagen• Collagen formation: mRNA mediatedCollagen formation: mRNA mediated• Fibroblast interferon ß( IFN- ß): inhibitor of collagenesisFibroblast interferon ß( IFN- ß): inhibitor of collagenesis• Transforming Growth Factor TGF ß 1 (adult): stimulates Transforming Growth Factor TGF ß 1 (adult): stimulates

collagenesiscollagenesis• TGF ß 3 (infant): inhibits collagenesisTGF ß 3 (infant): inhibits collagenesis• Renovo/ Retinae: inhibitors of TGF- ß1 activation: reduced Renovo/ Retinae: inhibitors of TGF- ß1 activation: reduced

collagenesis collagenesis

improving scarsimproving scars

• Gamma interferons and other cytokines down regulate collagen Gamma interferons and other cytokines down regulate collagen and matrix synthesis and increase monocyte retention within the and matrix synthesis and increase monocyte retention within the woundwound

Modern Scar Concepts (3)Modern Scar Concepts (3) Collagenesis - Collagenesis - Deposition - Deposition - ResorptionResorption

Collagen Deposition & ResorptionCollagen Deposition & Resorption• Fibroblast and monocyte collagenase: Fibroblast and monocyte collagenase: reduce collagen depositionreduce collagen deposition• Metalloproteinases Metalloproteinases inhibit collagenasesinhibit collagenases: promoting collagen : promoting collagen

depositiondeposition• Expression of fetal metalloproteinase: loss of scarless healingExpression of fetal metalloproteinase: loss of scarless healing• Intralesional steroids inhibit fibroblast growth Intralesional steroids inhibit fibroblast growth inhibit collagen deposition:inhibit collagen deposition: - - increaseincrease monocyte monocyte collagenasecollagenase

secretionsecretion - no influence on metalloproteinase - no influence on metalloproteinase - no influence on collagen production- no influence on collagen production

Modern Scar Concepts Modern Scar Concepts (4)(4) ++ The Role of Tissue Hypoxemia The Role of Tissue Hypoxemia --

• -- impedes epithelialisation impedes epithelialisation

• -- increases infection: neutrophil dependent increases infection: neutrophil dependent

• + reduces collagenesis in an epithelialised wound + reduces collagenesis in an epithelialised wound

• + compression and radiation lead to local + compression and radiation lead to local fibroblasticfibroblastic

hypoxemiahypoxemia

• : Compression and radiation should be used : Compression and radiation should be used afterafter

epithelialisation is completeepithelialisation is complete

Summary of Treatments for Hypertrophic Scar and Summary of Treatments for Hypertrophic Scar and KeloidsKeloids

• SurgerySurgery• Laser ExcisionLaser Excision• Pulse Dye Laser ReductionPulse Dye Laser Reduction• CryotherapyCryotherapy• Pressure TherapyPressure Therapy• RadiotherapyRadiotherapy• Steroid, Interferon, 5-FU Injections, ColchicineSteroid, Interferon, 5-FU Injections, Colchicine• Topical Aldara 5%Topical Aldara 5%• Prolonged tapingProlonged taping**• Silicone gel/sheetingSilicone gel/sheeting** ** patient controlled patient controlled

inexpensiveinexpensivenon-prescriptionnon-prescriptionfew if any complicationsfew if any complicationswell toleratedwell tolerated

Prolonged Paper Tape To Prolonged Paper Tape To ScarScar

• 70 pts acute scars: s/p caesarian section, Brisbane, Australia70 pts acute scars: s/p caesarian section, Brisbane, Australia• Micropore tape to randomized 1/2 pts after staple removal 4-7 days Micropore tape to randomized 1/2 pts after staple removal 4-7 days

post-oppost-op• Tape applied continuously for 12 weeksTape applied continuously for 12 weeks• The control group received no treatmentThe control group received no treatment• Scar volume was assessed by ultrasoundScar volume was assessed by ultrasound• Scar volume was reduced in the treatment group (p<0.05)Scar volume was reduced in the treatment group (p<0.05)• High correlation between subjective scar rating & intradermal scarring High correlation between subjective scar rating & intradermal scarring ( p<0.001)( p<0.001)• Authors postulate that tension is the cause of significant scarringAuthors postulate that tension is the cause of significant scarring

Atkinson,et al, PRS Nov 2005; 116 (6), 1648-Atkinson,et al, PRS Nov 2005; 116 (6), 1648-

Management of Common KeloidsManagement of Common Keloids

• Earlobe - If primary excision: Earlobe - If primary excision: 3 x daily peroxide and triple antibiotic3 x daily peroxide and triple antibiotic remove nylon 5.0 sutures at 10-14 days, then:remove nylon 5.0 sutures at 10-14 days, then: Dermajet inject Kenalog (trimacinolone 40mg/ml) Dermajet inject Kenalog (trimacinolone 40mg/ml)

start Kelo-cote after sutures out for at least 3 start Kelo-cote after sutures out for at least 3 monthsmonths

start compressive clamp start compressive clamp ““ear-ringear-ring”” : no Nickel : no Nickel return every 6 weeks for further injectionsreturn every 6 weeks for further injections

• Berman B, Bieley HC.  Dermatol Surg 1996 Feb;22(2):126-30– excision alone: 45-100 % recurrence– excision and Kenalog injection: < 50 % recurrence– excision and irradiation: < 10% recurrence– excision and button compression: no recurrences

www.delasco.com tel: 1 800 320-9612 tel: 1 800 320-9612

Management of Common Management of Common KeloidsKeloids

• Earlobe - if secondary excision:Earlobe - if secondary excision: excise and within 14 days: post-op irradiationexcise and within 14 days: post-op irradiation either one dose of 10 Gy or up to 15 Gy in 2-4 fractionseither one dose of 10 Gy or up to 15 Gy in 2-4 fractions sutures out 14 days post-opsutures out 14 days post-op Kenalog injection, compressive ear-ring and 6 week follow-upKenalog injection, compressive ear-ring and 6 week follow-up

Klumpar DI, Murray JC, Anscher M.  J Am Acad Dermatol 1994 Aug;31(2 Pt 1):225-31

- Dose irradiation most important factor: give >900c Gy- Dose irradiation most important factor: give >900c Gy - Irradiation completed within 1-3 weeks equally effective- Irradiation completed within 1-3 weeks equally effective

- ear lobe 98% successful at > 1 yr follow-up- ear lobe 98% successful at > 1 yr follow-up - small subsequent recurrences can be re-irradiated: 15 Gy- small subsequent recurrences can be re-irradiated: 15 Gy

Improvement of Erythematous and Hypertrophic Scars Improvement of Erythematous and Hypertrophic Scars by he 585-nm Flashlamp-pumped Pulsed Dye Laser, by he 585-nm Flashlamp-pumped Pulsed Dye Laser, Tina Alster. Ann Plast Surg 1994;32:186-190Tina Alster. Ann Plast Surg 1994;32:186-190

• 14 healthy subjects with hypertrophic and or erythematous scars as 14 healthy subjects with hypertrophic and or erythematous scars as a results of trauma a results of trauma

• Scars were at least 2 years oldScars were at least 2 years old• Candela flashlamp-pumped dye laser: 6.5-6.75 J/cm2 1-2 treatmentsCandela flashlamp-pumped dye laser: 6.5-6.75 J/cm2 1-2 treatments• 57% improved: lightening and flatter after one treatment57% improved: lightening and flatter after one treatment• 83% improved after 2 treatments83% improved after 2 treatments• Continued improvement over 6 monthsContinued improvement over 6 months• Improvement was not location specific, Improvement was not location specific, depth of scar not assesseddepth of scar not assessed

Irradiation mostly contraindicatedIrradiation mostly contraindicated

Re-resection definitely harmfulRe-resection definitely harmful

Laser excision usually harmfulLaser excision usually harmful

Pulse Dye lasers not helpfulPulse Dye lasers not helpful

Aldara 5% not helpfulAldara 5% not helpful

Silicone sheeting not helpfulSilicone sheeting not helpful

Steroid injections very helpfulSteroid injections very helpful

Kelo-cote helpful if < 5mm raisedKelo-cote helpful if < 5mm raised

Kelo-cote® unique Kelo-cote® unique formulationformulation

• Kelo-cote® composition: Kelo-cote® composition:

– Long chain polymers of silicone Long chain polymers of silicone (Polysiloxanes)(Polysiloxanes)

– Minimal Silicone dixoide cross links Minimal Silicone dixoide cross links polymerspolymers

– A volatile solvent allows silicone to dry on A volatile solvent allows silicone to dry on the stratum corneum in an ultra-thin sheetthe stratum corneum in an ultra-thin sheet

Silicone CompositionSilicone Composition Silanes: monomers

R Characteristics Methyl Hydrophobicity & Low surface tension Higher Alkyl Organic-compatibility  and Paintability Phenyl Thermo-stabile,Organo-compatible, Hydrophobic

CF3CH2CH2 Solvent resistant

Siloxanes: polymers

more crosslinked: more solidrecurring silicone / oxygen backboneend / side chains determine functionality

ie.: amine,carboxy, hydroxyl,epoxyl

RRRR

R:R:

Favorable properties related to scar Favorable properties related to scar reductionreduction

• Intermediate forms: elastomers: gel, rubberIntermediate forms: elastomers: gel, rubber• Solid-liquid binding requires catalyst Solid-liquid binding requires catalyst ‘‘curingcuring’’: ie. platinum, : ie. platinum, stannous octoatestannous octoate• Delivery in an evaporative solvent may provide the ability to Delivery in an evaporative solvent may provide the ability to change change the properties of the silicone upon deliverythe properties of the silicone upon delivery

• Properties influencing scar reduction include:Properties influencing scar reduction include:– Thickness:Thickness: < 0.254mm < 0.254mm– Moisture vapor transmission rate:Moisture vapor transmission rate: <15mg/cm2/day <15mg/cm2/day– Oxygen permeability:Oxygen permeability: > 600cc/100 in.sup.2/day > 600cc/100 in.sup.2/day– High stretch:High stretch: ,1.5lbs/in stretches > 110% length ,1.5lbs/in stretches > 110% length– Tensile strength:Tensile strength: >100g >100g– Penetrability:Penetrability: 4-7mm 4-7mm– Peel strength:Peel strength: 2-6 g 2-6 g

Silicone Mode of ActionSilicone Mode of Action

• Potential TheoriesPotential Theories

– Hydration: increasesHydration: increases– Oxygenation: decreasesOxygenation: decreases– Protection: increasesProtection: increases– Cellular Strain: increases ?Cellular Strain: increases ?– Modulation of growth factorsModulation of growth factors

Silicone Mode of ActionSilicone Mode of Action

HydrationHydration

• Kelo-cote is semi-occlusive aerating and hydratingKelo-cote is semi-occlusive aerating and hydrating

• Silicone absorption is limited to the epidermis Silicone absorption is limited to the epidermis

• Stratum corneum regulates fibroblast /collagenesisStratum corneum regulates fibroblast /collagenesis

• Hydration normalises the collagen synthesisHydration normalises the collagen synthesis

Silicone Mode of ActionSilicone Mode of Action

HydrationHydration

• But not all breathable dressings will reduce scarsBut not all breathable dressings will reduce scars

• In a study comparing silicone and hydrogel dressings,In a study comparing silicone and hydrogel dressings, silicone normalised collagen synthesis, silicone normalised collagen synthesis, other breathable non-silicone dressings did notother breathable non-silicone dressings did not

• Silicone has a scar reducing characteristic not seen with Silicone has a scar reducing characteristic not seen with polyurethanespolyurethanes

• Further research ongoingFurther research ongoing

Silicone Mode of Silicone Mode of ActionAction

ProtectionProtection

• Microbial, chemical or physical irritation promote excessive collagen Microbial, chemical or physical irritation promote excessive collagen production in early scars:production in early scars:

• Keratinocyte dependent: exposed cell release growth factorsKeratinocyte dependent: exposed cell release growth factors• Fibroblast dependent: Staph epidermidis Immortalization TheoryFibroblast dependent: Staph epidermidis Immortalization Theory• Intact dermis is necessary for normal wound healingIntact dermis is necessary for normal wound healing

Silicone Mode of ActionSilicone Mode of Action

Modulation TheoryModulation Theory

• Silicones oils and sheeting appear to have an influence on Silicones oils and sheeting appear to have an influence on Fibroblast growth factors and transforming growth factorsFibroblast growth factors and transforming growth factors

• Silicone reduces FGFSilicone reduces FGF growth factors in vivo, yetgrowth factors in vivo, yet ( opposite in vitro )( opposite in vitro )

– Fibroblast are reduced Fibroblast are reduced – Collagenase is increased Collagenase is increased

• ““Collagen production is normalised” Collagen production is normalised”

History of Silicone in Scar History of Silicone in Scar ReductionReduction

• Perkins et al, 1983Perkins et al, 1983: reported silicone a new treatment for hypertrophic scars: reported silicone a new treatment for hypertrophic scars• Ahn, et al, 1989Ahn, et al, 1989: silicone gel improved texture, color, thickness and: silicone gel improved texture, color, thickness and

itching from small hypertrophic scars itching from small hypertrophic scars

• Sawada & Sone, 1990Sawada & Sone, 1990: 20% silicone gel 82% improved hypertrophic : 20% silicone gel 82% improved hypertrophic

scars and keloids a.c.t. glycerin 22% improvedscars and keloids a.c.t. glycerin 22% improved• Sawada &Sone, 1992Sawada &Sone, 1992: silicone gel an elastomer sheeting vs. petroleum, : silicone gel an elastomer sheeting vs. petroleum,

6 months f/u silicone group much softer, less red 6 months f/u silicone group much softer, less red• Pamieri, et al, 1995Pamieri, et al, 1995: Found Vit E enhanced hypertrophic scar and keloids: Found Vit E enhanced hypertrophic scar and keloids• Phillips, et al. 1996Phillips, et al. 1996: hydrocolloid dressings no evidence to support reduce: hydrocolloid dressings no evidence to support reduce

scarring after hypertrophic scar or keloid established scarring after hypertrophic scar or keloid established

Good review: Mustoe, et al, PRS 2002:110(2) 560-Good review: Mustoe, et al, PRS 2002:110(2) 560-

Literature lacks double blind placebo controlled studiesLiterature lacks double blind placebo controlled studies

Placebo Controlled Pilot Study Evaluating Kelo-cote Placebo Controlled Pilot Study Evaluating Kelo-cote in the Reduction of Scarring Following Cleft Lip Repairin the Reduction of Scarring Following Cleft Lip Repair

10 days post-op10 days post-op 8 weeks post-op8 weeks post-op 8 months post-8 months post-opop

• 33 patients, Santiago, Chile, 199633 patients, Santiago, Chile, 1996• Methods: mm vertical scar shortening Methods: mm vertical scar shortening (A-B)(A-B) mm depth lip notchmm depth lip notch *average width scar mm*average width scar mm scar softness 0-3 gradescar softness 0-3 grade scar erythema 0-3 gradescar erythema 0-3 grade• 6 week follow-up results6 week follow-up results

**

AA BB

Markedly reduced erythema (p< 0.005)Markedly reduced erythema (p< 0.005)Reduced horizontal scar width ( p<0.05) Reduced horizontal scar width ( p<0.05)

Chan, et al, 2005: PRS Sept 15Chan, et al, 2005: PRS Sept 15

• Placebo controlled study prospective clinical Placebo controlled study prospective clinical trialtrial of silicone gel ( Scarfade of silicone gel ( Scarfade ®®) in the ) in the prevention of hypertrophic median prevention of hypertrophic median sternotomy scarssternotomy scars– 100 wounds/50 pts Malaysia100 wounds/50 pts Malaysia– Reduction of: Reduction of: pigmentation (p=0.02) pigmentation (p=0.02) vascularity (p=0.001)vascularity (p=0.001) pliability (p=0.001)pliability (p=0.001) height (p=0.001)height (p=0.001) pain (p=0.001)pain (p=0.001) itchiness (p=0.001)itchiness (p=0.001)

Sebastian et al, 2005Sebastian et al, 2005

• • Non-placebo controlled study Kelo-cote on scars: all-comers, Non-placebo controlled study Kelo-cote on scars: all-comers, up to 48up to 48

month follow-upmonth follow-up

• Data 111 patients Germany, Switzerland & Data 111 patients Germany, Switzerland & AustriaAustria

• Study: legal requirement for ‘new’ productsStudy: legal requirement for ‘new’ products

• Independent studyIndependent study

• Data is on all types of scarsData is on all types of scars

• Different ages of scarsDifferent ages of scars

• Measurement tool is Vancouver scar scale, Measurement tool is Vancouver scar scale, which which

is standard measurement for scarsis standard measurement for scars

Sebastian et al, 2005Sebastian et al, 2005

• Patients & physicians assessment of Patients & physicians assessment of tolerability and efficacy using 4 point tolerability and efficacy using 4 point scalescale

• Vancouver scar scaleVancouver scar scale

Sebastian et al, 2005Sebastian et al, 2005

Results of patient and physician assessment - Results of patient and physician assessment - EfficacyEfficacy

Sebastian et al, 2005Sebastian et al, 2005Results of patient and physician assessment - Results of patient and physician assessment -

TolerabilityTolerability

Sebastian et al, 2005Sebastian et al, 2005

Decrease in Vancouver Scar Scale - RednessDecrease in Vancouver Scar Scale - Redness

Sebastian et al, 2005Sebastian et al, 2005

Decrease in Vancouver Scar Scale - Decrease in Vancouver Scar Scale - ElevationElevation

Sebastian et al, 2005Sebastian et al, 2005

Decrease in Vancouver Scar Scale - Decrease in Vancouver Scar Scale - HardnessHardness

Sebastian et al, 2005Sebastian et al, 2005

Decrease in Vancouver Scar Scale - Decrease in Vancouver Scar Scale - PainPain

Sebastian et al, 2005Sebastian et al, 2005 Results by type of scarResults by type of scar

Sebastian et al, 2005Sebastian et al, 2005 Results by age of scarResults by age of scar

Summary of studySummary of study

• Kelo-coteKelo-cote® rated:good/very good > 80% patients & physicians® rated:good/very good > 80% patients & physicians• Physicians rated tolerability: Physicians rated tolerability: good/very good 100% of patientsgood/very good 100% of patients• Kelo-coteKelo-cote® decreased: redness, elevation, hardness,itchiness ® decreased: redness, elevation, hardness,itchiness

and pain of scars over a two month periodand pain of scars over a two month period• Kelo-coteKelo-cote® can be used on old and new scars® can be used on old and new scars• Kelo-cote® can be used to treat all types of scarsKelo-cote® can be used to treat all types of scars

Indications for useIndications for use

• Kelo-cote® is indicated for the management of:Kelo-cote® is indicated for the management of:– Acute healing scarsAcute healing scars– Hypertrophic scarsHypertrophic scars– KeloidsKeloids

• Kelo-cote®™ has also been used for scars Kelo-cote®™ has also been used for scars resulting from:resulting from:– TraumaTrauma– BurnsBurns– SurgerySurgery– AcneAcne– Post laser erythemaPost laser erythema

Length of treatmentLength of treatment

• Minimum treatment should be 2 monthsMinimum treatment should be 2 months• Treat larger and older scars >3 monthsTreat larger and older scars >3 months• Active persons apply usually in amActive persons apply usually in am• May treat with other topicals in pmMay treat with other topicals in pm

Instructions for use 0.5 oz Kelo-Instructions for use 0.5 oz Kelo-cotecote

• Ensure the area is clean and dry. Ensure the area is clean and dry.

• Apply Apply a very thin layer and allow to drya very thin layer and allow to dry

• Apply once daily, or twice daily Apply once daily, or twice daily

• Maximum effect, 24 hours of continuous contactMaximum effect, 24 hours of continuous contact

• Once dry, OK to cover with pressure garments, sun block or Once dry, OK to cover with pressure garments, sun block or cosmeticscosmetics

• If not dried within 4–5 minutes: too muchIf not dried within 4–5 minutes: too much

• Gently remove the excess and allow the dryingGently remove the excess and allow the drying

• Larger and older scars > 90 days Larger and older scars > 90 days

• 0.5 oz contains enough Kelo-cote®, for: 7.5–10cm 2x/day for 0.5 oz contains enough Kelo-cote®, for: 7.5–10cm 2x/day for 90 days 90 days

• Reduce drying time hotter climates, keep in the refrigerator Reduce drying time hotter climates, keep in the refrigerator

• In colder weather, use low setting on hair dryer to reduce In colder weather, use low setting on hair dryer to reduce drying timedrying time

Warnings and Warnings and PrecautionsPrecautions

• Avoid direct contact with eyes, mucous Avoid direct contact with eyes, mucous membranes, & open wounds membranes, & open wounds

• Kelo-cote® may stain clothing if not Kelo-cote® may stain clothing if not completely drycompletely dry

• Store below 77°F (25°C) Store below 77°F (25°C)

• Do not use after the expiration dateDo not use after the expiration date

Mederma: $25, 50g, EtOH, water,PEG-4,xanthum gum, Mederma: $25, 50g, EtOH, water,PEG-4,xanthum gum, sorbic acidsorbic acid

Scarguard: $72, 100g, with hydrocortisone, Vit EScarguard: $72, 100g, with hydrocortisone, Vit E

Cimeosil: $56, 14 gram, polysiloxanesCimeosil: $56, 14 gram, polysiloxanes

Skin Esthetique: $24, 170g,dimethicone, arnika, Skin Esthetique: $24, 170g,dimethicone, arnika, copper,copper, seaweedseaweed  

Scarfade: $25, 50g, silicone dioxide, micro quartz Scarfade: $25, 50g, silicone dioxide, micro quartz crystalscrystals +/- vit E,K, co-enzyme Q-10+/- vit E,K, co-enzyme Q-10

Pro-Sil: $17.50, glide-on, silicone Pro-Sil: $17.50, glide-on, silicone ““creams and oilscreams and oils””

• Kelo-cote® is a uniqe patent protected silicone gel Kelo-cote® is a uniqe patent protected silicone gel

• 80% patients rate Kelo-cote® as good or very good in scar 80% patients rate Kelo-cote® as good or very good in scar reductionreduction

• 100% physicians rate Kelo-cote® good or very good in pt 100% physicians rate Kelo-cote® good or very good in pt tolerabilitytolerability

• Kelo-cote® softens, flattens &reduces the redness of old & new Kelo-cote® softens, flattens &reduces the redness of old & new scarsscars

• Kelo-cote® is a comaparatively cost effective treatmentKelo-cote® is a comaparatively cost effective treatment

Clinicial Care:Clinicial Care:’’OlsenOlsen’’s Rules Rule’’

• ““Most wounds heal proportionate to the time Most wounds heal proportionate to the time and attention they are givenand attention they are given””

• Steristrip minimum of 4 - 7 days & then another Steristrip minimum of 4 - 7 days & then another 5 days after changing strips5 days after changing strips

• Early application of Kelo-cote, avoid any contact Early application of Kelo-cote, avoid any contact with clothing for 6 weeks minimum: diapers OKwith clothing for 6 weeks minimum: diapers OK

• All open wounds treated with 1/2 peroxide, All open wounds treated with 1/2 peroxide, bacitracin,bacitracin,

minimum of twice dailyminimum of twice daily

HandHand

Breast ReductionBreast Reduction

Breast AugmentationBreast Augmentation

Mastopexy AugmentationMastopexy Augmentation

Verbal testimonial: Mastopexy AugmentationVerbal testimonial: Mastopexy Augmentation

Breast Cancer Breast Cancer ReconstructionReconstruction

• Bilateral Transverse Rectus Abdominus Myocutaneous FlapBilateral Transverse Rectus Abdominus Myocutaneous Flap

AbdominoplastyAbdominoplasty

<Olsen<Olsen’’s Rules Rule

Facial TraumaFacial Trauma

FaceliftFacelift

Head and Neck Excisional SurgeryHead and Neck Excisional Surgery

Cleft Lip SurgeryCleft Lip Surgery

Looking into the FutureLooking into the Future

Bioglass and nano crystal Silver SprayBioglass and nano crystal Silver Spray