La Trobe Presentation - Sept 7
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Transcript of 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%
Antibacterial Cineole Films
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.
A. Pegalajar-Jurado, C.D. Easton, K.E. Styan and S.L. McArthur, Journal of Materials Chemistry B, 2014, 2, 4993
Antibacterial Cineole Films
PP Cineole PP Octadiene Glass slide
A. Pegalajar-Jurado, C.D. Easton, K.E. Styan and S.L. McArthur, Journal of Materials Chemistry B, 2014, 2, 4993
Confocal microscopy with LIVE/DEAD staining – E-Coli
Antibacterial Cineole Films
*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
Supported Lipid Bilayers
lipid in organic solvent
vesicle adsorption/rupture
bilayer formation
Supported Lipid Bilayers
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
Supported Lipid Bilayers
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
Supported Lipid Bilayers
• 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
For SLBs Decrease F = increase mass
For SLBs Decrease F = increase mass
Acrylic acid – pH 4 then pH 7Vesicle addition @ pH 4 Rinse @ pH 7
Supported Lipid Bilayers
• 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