advanced wound care adhesives with improved - orbit.dtu.dk22. marts 2019 dtu kemiteknik annual...

DTU Kemiteknik22. marts 2019 Annual Polymer Day 2

Advanced Wound Care Adhesives with ImprovedMoisture Handling Capabilities

Valeria Chiaula1,2, Piotr Mazurek1, Anders C. Nielsen2, Anne L. Skov1

1. DTU – Chemical Engineering – The Danish Polymer Centre

2. Coloplast A/S – GRD, TECH- Adhesives

Annual Polymer Day – 22/03/2019


Chronic wounds

Significant disability

Amputation

Increased mortality

Elderly and/or diabetic patients


Incorrect wound healing process

Chronic wounds stall in inflammatory/proliferative phases

Hyperproliferation

Chronic inflammation

Infections


Correct wound healing process

Moist, warm and clean wound’s bed

Moist wound bed promotes wound’s closure

Wound’s environment control


Allows moisture transmission

Mantains correct moisture in the wound bed and skin

Dressing for appropriate wound environment

GOAL

Wounded skin

Liquids/sweat from wound and skin

Dressing


Silicone adhesives

Low degree of cross-linkingdensity

Great potential in wound care applications due to its gentle skin adhesion properties


Limited moisturetransportation due to hydrophobicity

Low absorption and incompatibility with high exudingwounds and/or large amount of sweat from skin

Silicone adhesives

Risk of failure prematurely


Current solutions on the market


Mechanical holes in the border region of the silicone adhesive layer

Issues related to making holes

• Manufacturing

• Minor flexibility

• Risk of holes’ closure


PDMS

Glycerol

Development of novel, skin-friendly glycerol-silicone hybrid adhesives

Our solution13-12-2019


PDMS

Hydrophobic and nowater transport, but

permeable to gas (oxygen, water vapor)

Glycerol

Hydrophilic and causesthe water to be

absorbed in significantamounts

Improved moisture handling properties

13-12-2019


SA* Part A SA* Part B

1:1

Glycerol: X phr*

SpeedMixer DAC 150 FVZ-K

3500 rpm, 1 min

Glycerol-in-silicone emulsion

SA*: S stands for silicone, A for adhesive

GX*: G stands for glycerol, X for glycerol phr*, which is glycerol weight amount per hundred parts of silicone

High shear forces to immiscible mixtures of hydrophilic glycerol and hydrophobic silicone

GX*_SA

Experimental

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100 µm 100 µm

G20_SA t = 0 min G20_SA t = 60 min

Stability and morphology of the emulsions

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100 µm

µm100 µm

0

2

4

6

8

0 60

aver

age

size

(µ

m)

t (min)

G20_SA t = 0 min G20_SA t = 60 min

Stability and morphology of the emulsions

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Glycerol-in-silicone emulsion

Curing

80 ˚C, 1h

Hybrid adhesive

From emulsions to adhesives

Thickess 0.3 mmRelease liner: PET

13-12-2019


Water absorption + permeability after 24h –TM0291

13-12-2019

DTU Kemiteknik22. marts 2019 Annual Polymer Day

0

0.2

0.4

0.6

0.8

1

1.2

1.4

SA G10 G20 G30 G40 G50 G60 G70

Ab

s +

Perm

g/c

m2

Composition

18

Water Absorption Permeability

Water absorption + permeability after 24h –TM0291

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Ability to resist separation from skin surface after a period of application – long-term measurement

Maximum adhesion upon initial application to skin

Gradually decreases due to transdermal waterevaporation

Peel adhesion

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Peel test – TM0037

Substrate: stainless steelplates

Peel temperature: 32 C

Peel rate: 5 mm/s

Peel angle: 180°

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Peel force vs glycerol loading

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Pure SA G10 G20 G30 G40 G50 G60 G70

Peel

Fo

rce

(N)

Composition

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G70G60

After peel test… cohesive failure13-12-2019


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Peel test

Substrate: skin-like material

Peel temperature: 32 C

Peel rate: 5 – 1 – 0.1 mm/s

Peel angle: 180°

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DTU Kemiteknik22. marts 2019 Annual Polymer Day

0

0.5

1

1.5

2

2.5

3

3.5

Pure SA G10 G20 G30 G40 G50

Peel

Fo

rce

(N)

Composition

Peel force vs peel rate on skin-like substrate

26

1

Peel rate 5 mm/s Peel rate 1 mm/s Peel rate 0,1 mm/s

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Tack

Short-term measurement

Shows initial tendency of adhesives to stick to the skin

High level of tack required to hold adhesives in position

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Tack test – ASTM 6195-D03

Tack vs glycerol loading

0

2

4

6

8

10

Pure SA G10 G20 G30 G40 G50 G60 G70

Tack

Fo

rce

(N)

Composition

13-12-2019


G70G60

After tack test… cohesive failure13-12-2019


Conclusions

Simple manufacturing and possibility of glycerol domains’ size control– no holes-related issues

Improved moisture handling capabilities compared to pure silicone

Versatile system, tunable according to patients’ requirements – extentof liquids that need to be absorbed

Adhesion and tack not compromised

Glycerol-silicone adhesives

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Collaboration and support of Piotr Mazurek, Anne L. Skov and Anders C. Nielsen

The Danish Polymer Centre

Acknowledgements13-12-2019


Thank you!

13-12-2019

advanced wound care adhesives with improved - orbit.dtu.dk22. marts 2019 dtu kemiteknik annual...

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