La Trobe Presentation - Sept 7

The ANFF Biointerface Engineering Hub……..Dr. Karyn Jarvis

The ANFF Network• Funded under

the National Collaborative Research Infrastructure Strategy (NCRIS)

• 8 University based nodes

• Funds over 600 technical staff

• Each node offers specific expertise

ANFF-Vic

Monash Centre for Electron

Microscopy

Institute for Frontier

Materials

Materials Characterisation and Fabrication

Platform

Micro Nano Research Facility

Centre for Materials

Surface Science

CSIRO Manufacturing

Flagship

Biointerface Engineering

Hub

ANFF-Vic Biointerface Engineering Hub

• Instruments– 6 custom made plasma reactors– Spectroscopic Ellipsometer– Dipcoater– Langmuir Blodgett Trough– Quartz Crystal Microbalance - Dissipation

• Focuses on the use of synthetic and biological components to create surfaces and materials with new properties

• Previous outcomes have included a wide range of applications such as drug-membrane studies, selective surface patterning and studying viscoelastic behaviours of thin films

Plasma Reactors

• 6 custom made reactors for plasma polymerisation (plasma enhanced chemical vapour deposition) and plasma treatment

• <1-100 nm thin, pinhole-free thin films with specific functional groups

• Substrate independent• Up to 20 cm diameter samples• Variety of chemistries available:

• Amine• Alkane• Alcohol• Fluorocarbon• Carboxylic acid• Polyacrylamine• Alkane bromide (ATRP initiator)• Essential oils (antimicrobial)

• Anhydride• Hydrophilic• Hydrophobic• Thiol• PEO-like

Plasma PolymerisationMonomer

(Liquid)Monomer(Vapour)

Monomer(Plasma)

Plasma Polymer Film

Surface chemistry and thickness of the film can be manipulated by modifying:• Plasma power (W)• Monomer flow rate (sccm)• Polymerization time (min.)

Monomer

ConventionalPolymer

Plasma Polymer

Electrode

Characterisation & Film Deposition

Spectroscopic Ellipsometry

Determines the thicknesses of films between 2 nm and 3 µm

Quartz Crystal Microbalance

Studies surface phenomena such as thin film formation and adsorption

Characterisation & Film Deposition

Langmuir Blodgett Trough

Creates monolayer on surface of water which can be transferred to surface

Multivessel Dip Coater

Deposits thin films from solution by self assembly, sol-gel chemistry or layer by

layer deposition

Antibacterial Cineole Films

A. Pegalajar-Jurado, C.D. Easton, K.E. Styan and S.L. McArthur, Journal of Materials Chemistry B, 2014, 2, 4993

0.05%

0.2%

• Essential oil derived from eucalyptus leaves

• Also known as eucalyptol• Eucalyptus oil is up to

90% cineole

Carried out by Adoracion Pegalajar-Jurado

E-Coli

0.35%0.5%


0

20

40

60

80

100

1 2 3 4

XPS

Ato

mic

Con

cent

rati

on (%

) C O N

0

20

40

60

80

100

1 2 3

Cont

act

angl

e (º

)

As deposited

16 hwater

16 hPBS

16 hbrothglass

slideppCoppOct

0

10

20

30

40

50

60

1 2 3

Thic

knes

s (n

m)

As deposited

16 hwater

16 hPBS

Cineole deposition - 20 W, 2 sccm, 20 min.



PP Cineole PP Octadiene Glass slide


Confocal microscopy with LIVE/DEAD staining – E-Coli


*p<0.1**p<0.01***p<0.001

After 5 days

Modification of Electrospun Fibers

M. Abrigo, P. Kingshott and S.L. McArthur, Biointerphases, 2015, 10, 04A301

Carried out by Martina Abrigo

• Electrospun fibers are used in:– Protective clothing

– Filtration membranes

– Nanosensors

– Medical devices

• When used as membranes to filter air or water, fibers are susceptible to bacterial attachment and therefore biofilm formation

Electrospun fibers20% w/v polystyrene in dimethylformamide with 0.1

% surfactantAverage diameter: 500 ± 200 nm

CineoleAcrylic acidOctadiene Allylamine

Modification of Electrospun FibersUncoated PS PP Acrylic Acid

PP Octadiene

PP Allylamine

Confocal microscopy with LIVE/DEAD staining

PP Cineole

Lower number of total bacteria

High number of dead bacteria

Highest proportion of live cells

More live cells than uncoated PS

Most cells appear dead

M. Abrigo, P. Kingshott and S.L. McArthur, Biointerphases, 2015, 10, 04A301

Supported Lipid Bilayers

Carried out by Hannah Askew

• Cell membranes are composed of lipids and proteins organized into a bilayer structure 3 – 5 nm thick

• Supported lipid bilayers (SLBs) provide a model system that enable precise control over membrane structure to enable the study of specific functions and interactions

• Can be formed by Langmuir trough or vesicle collapse• Vesicle adsorption and collapse is influenced by a number of factors, such as surface

chemistry


lipid in organic solvent

vesicle adsorption/rupture

bilayer formation


Acrylic acid Allylamine

1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC)

Deposition parameters: 20 W, 1.5 sccm, 20 min.

CA=50° 58 nm CA=61° 30 nm


For SLBs Decrease F = increase mass

• Large ΔF and ΔD• Indicates adsorbed vesicles• Remain stable after rinsing

Allylamine – pH 7Vesicle addition

@ pH 7Rinse

@ pH 7


• Only small changes in F and D• Indicates few vesicles attached• Easily rinsed off suggest weak

interactions

Acrylic acid – pH 7

Vesicle addition @ pH 7

Rinse @ pH 7



Acrylic acid – pH 4 then pH 7Vesicle addition @ pH 4 Rinse @ pH 7


• Large ΔF and ΔD @ pH 4• Indicates adsorbed vesicles• Remain stable after rinsing• F increases @ pH 7• Indicates vesicle collapse

Summary

• Plasma polymerization is an effective technique formodifying surfaces for a number of applications

• Plasma polymerised cineole films have shown to reduceE-Coli bacteria and resulting biofilm growth

• A variety of plasma polymerised films have shown toimpact E-Coli bacteria integration into and growth onelectrospun fibers

• Plasma polymerized films can be used to manipulatevesicle adsorption and collapse

Current Projects• Colloidal silica to prevent S. epidermidis bacterial attachment

– Naturally occurring bacteria that can contaminate implants

– Colloidal silica roughens surface to inhibit bacterial attachment

– Allylamine plasma polymer creates uniform surface chemistry to confirm inhibition of bacterial attachment is due to surface roughness

• Culturing platform for muscle stem cells– Ultrathin plasma polymer coatings (< 5 nm) coated onto conductive surface for the

growth of muscle stem cells

– Films need to be thin enough to maintain conductivity and surface roughness

– Effect of film thickness and chemistry on cell proliferation will be investigated

Acknowledgements

http://www.anff.org.au/

• Collaborators– Prof. Peter Kingshott (Swinburne)– Dr. Christopher Easton (CSIRO)– Dr. Katie Styan (CSIRO)– Prof. Joe Shapter (Flinders)

• Funding– L.E.W Carty Foundation– Rural Industries Research and Development

Corporation– Swinburne Chancellor’s Research scholarship– Swinburne FEIS scholarship– Advanced Manufacturing CRC scholarship

La Trobe Presentation - Sept 7

Documents

Transcript of La Trobe Presentation - Sept 7