Marletta

Micro- e Nanotecnologie per

Superfici Biocompatibili

Giovanni MARLETTAUniv. of Catania and CSGI – Italy

Laboratory of Molecular Surfaces and Nanotechnology(LAMSUN) – http://www.unict.it/dipchi/Lamsun

PARTE I.

CONCETTI GENERALI

Materiali Biocompatibili vs. Materiali Biomimetici

• Materiali BIOMIMETICI: Materiali fabbricatimediante processi analoghi a quelli naturali, tipicidi sistemi biologici.

• Materiali BIOCOMPATIBILI: materiali sintetici o naturali capaci di sostituire e/o riparare tessuti biologici o funzioni corporee: La biocompatibilità implica il mantenimento delle funzionalità biologica delle biomolecole o cellule a contatto con il materiale.

Protesi e dispositivi

Le applicazioni specifiche e la variabile Tempo

- Dispositivi Biomedici: Biosensori in vivo, Membraneper dialisi, lenti a contatto, etc…(Tempo di interazione: alcune ore)

- Sostituti temporanei: Cateteri urinari, sonde, suture,etc… (Tempo di interazione: giorni-settimane)

- Sostituti permanenti: Organi artificiali, Protesid’anca, lenti intraoculari, Vasi sanguigni e valvole cardiache artificiali; Muscoli artificiali, etc… (Tempo di interazione: 20-30 anni)

SAMSAMNew Generation New Generation

NanodevicesNanodevices

electronicselectronics

photonicsphotonicsbiologybiology

medicinemedicine

Light or electrical Light or electrical stimulistimuli

specific functionsspecific functions

Layers of Layers of BiomoleculesBiomolecules

Biosensoriad altissima integrazione

(scala micro- e nanometrica)

Diverse Proteine simultaneamente “patterned” su una superficie di Si (Biswas and Reichert, 2001)

I Biomateriali interagiscono con l’ambiente biologico attraverso le superfici:

Chimica Fisica delle Superfici ed Interfacce !!

Fasi di Interazione Superfici-MezzoBiologico

I] Parametri Chimico-Fisici delle superfici

1) Energia Libera di Superficie: componenti dispersive, polari, acide e basiche;2) Idrofobicità/idrofilicità e Struttura dell’acqua alle interfacce;3) Topologia delle superfici e dimensioni critiche per l’interazione con specie biologiche;4) Domini elettrici alle superfici.

Tecniche di Caratterizzazione diSuperfici

Chemical structure:- X-Ray Photoelectron Spectroscopy (XPS);-Time-of-Flight Secondary Ion Spectrometry (ToF-SIMS); DynamicSIMS;- FT-IR and ATIR; (Micro)-Raman Spectroscopy and SERS

Micro- and Nanoscale Morphology

- Near Field Microscopies (AFM, STM, SNOM, etc.)- Optical Microscopy, Epifluorescence Microscopy, SEM

Surface Free Energy- Dynamic Contact Angle measurements (three liquids technique)

-Mass adsorption and Viscoelastic properties-QCM-D (Quartz Crystal Microbalance with Dissipation monitoring)

- Structure of the adsorbed layersNeutron, X-ray, Electron Diffraction Techniques

Surface Compositional and Phase modification (detected by in situ-XPS and Tof-SIMS, ex-situ FT-IR and ATIR; (Micro)-Raman Spectroscopy) Morphology Modification (Nanoscale) :

roughness, texturing occurrence, etc. (measured by Atomic Force Microscopy)

Surface Free Energy (measured by Static and Dynamic Contact Angle Measurements)

Adsorbed layer properties (adsorbed mass, viscoelastic prop.s: Quartz Crystal Microbalance with Dissipation monitoring)

II] Proprietà Chimico-Fisiche dei sistemi biologici

- Le biomolecole viste come Elettroliti polimerici; - Colloidi biologici e modelli elettrostatici;- Processi di folding/unfolding di proteine;- Topologia delle biomolecole e dimensioni critiche per l’interazione con superfici rugose;- Domini di gruppi funzionali alle superfici di macromolecole biologiche;- Domini elettricamente carichi su macromolecole biologiche;etc….

Interazioni Proteina–Superficie

III) Processi cellulari

1) Le cellule riorganizzano la membrana cellulare,

2) esprimono proteine specifiche,3) riorganizzano il citoscheletro,4) Aggregano i sistemi di ricettori, etc…

Interazioni Cellula-superfice: ruolo delle proteine


1) Energia Libera di Superficie: componenti dispersive, polari, acide e basiche;2) Idrofobicità/idrofilicità e Struttura dell’acqua alle interfacce;3) Topologia delle superfici e dimensioni critiche per l’interazione con specie biologiche;4) Domini elettrici alle superfici.

Modifica della Chimica di Superficie: Gruppi funzionali, idrofilicità, SFE.

Struttura finale:-IB: formazione di una fase SiOxCyHzamorfaPlasma: formazione di una fase iOx(OH)y

Aumenta la concentrazione dei gruppi elettron-donatori (Lewis) alla superficie

untreated

O2 rf Plasma-treated

50 keV ion-irrad

Untreatedvery hydrophobic

θ=93.0°±1.7°

Plasma/treatedhydrophilic

θ=12.8°±0.5°

Ion irradiatedhydrophobic

θ=51.7°±0.9°

0

20

40

60

80

untreated plasma-treated ion-irradiated

γ (m

J/m

2 )

SELWAcidBasic

*

*

***

*

****

**

Poli-idrossimetil-silossanoTrattato conIB - O2 rf plasma - Ar MW plasm

HSA

Lyz

Lf

Hydrophobic(untreated) PHMS rms=0.35±0.08 nm

Hydrophilic(plasma-treated) PHMS rms=0.28±0.04 nm

rms= 0.36±0.03 nm

rms= 1.29±0.02 nm

rms= 0.88±0.01 nm

rms= 0.31±0.01 nm

rms= 0.33±0.01 nm

rms= 0.45±0.25 nm

Different protein aggregation !

Thicker adlayer on the hydrophobic

surfaces

E-MRS 2006, May 29-June 2, Nice (France)

Modifying the Surface Chemistry (SiO2-ε Cεwith ε<0.1)Different cell behaviour and Protein organization

(Fibroblasts on PHMS)

Untreated PHMS O2 Plasma/air aged - PHMS

6 keV Ar+ irradiated-PHMS

C. Satriano, S. Carnazza, S. Guglielmino, and G. Marletta, J. Mat. Res: Mat. in Medicine, (2003)

AFM analysis:FBS-incubated samples:

1) Untreated PHMS

2) O2 plasma-treated PHMS

3) 6 keV ion-irradiated PHMS

AFM phase-contrast images:

0 1 0 1 3 1 0 1 4 1 0 1 50

2 0

4 0

6 0 γS

to t

γSL W

γSA B

Surfa

ce fr

ee e

nerg

y (m

J/m

2 )

F lu e n c e ( io n s /c m 2)

0 1 0 1 3 1 0 1 4 1 0 1 5 1 0 1 6

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0 θ a d v θ r e c

θ (d

egre

e)

F lu e n c e ( io n s / c m 2 )

Advancing and receding Contact Anglefor irradiated PHMS vs. ion fluence

Surface Free Energy components forirradiated PHMS vs. ion fluence

Modification of Surface Free Energyby irradiation (PHMS)

Si-OH instead of Si-CH3 (TOF-SIMS data)

x10

x10

Inte

nsity

(cou

nts)

m/z50 100 150

0.2

0.4

0.6

0.8

x 105

0.2

0.4

0.6

0.2

0.4

0.6

x10

43.00 43.10 45.00 45.10

43.00 43.10 45.00 45.10

43.00 43.10 45.00 45.10

28SiCH3+

C2 H3O+

C3 H7+

28SiOH+

C2 H5O+ unirradiated

5x1014 cm-2

in situ

5x1014 cm-2

48h aged in air

Ion irradiation:

• [CH3]- and [SiCHx]-related peaks decrease

• SiOH and [SiOx]-relatedpeaks increase

Aging in athmosphere:

• partial recovery of surface CHx‘s

• further increase in Si-OH content

Chemical Structure and Surface Free Energy:PHMS

A. Licciardello, C. Satriano, G. Marletta, in Secondary Ion Mass Spectrometry SIMS XII, A. Benninghoven, P. Bertrand, H.N. Migeon (Eds), Elsevier (2000) 889-892.

Chemical Structure and SurfaceFree Energy: PHMS

80 60 400 ,2

0 ,4

0 ,6

0 ,8

1 ,0

norm

aliz

ed S

iOH

yie

ld

C on tac t ang le (deg ree )

The correlation between the raising of the mass 45 (SiOH)and the raising of contact angle

BHK21 Fibroblasts on 5 keV Ar+-irradiated PHMS: SPREADING EFFECT (Inc. time = 48hrs.)

unirradiated

1x1014 ion/cm2 5x1014 ion/cm2

C. Satriano, E.Conte and G. Marletta., Langmuir, 17(2001), 2243.


1) Energia Libera di Superficie: componenti dispersive, polari, acide e basiche;2) Idrofobicità/idrofilicità e Struttura dell’acqua alle interfacce;3) Topologia delle superfici e dimensioni critiche per l’interazione con specie biologiche;4) Domini elettrici alle superfici;

Surface Topology and Cell Adhesion

Lithography (A.Curtis &C.Wilkinson)

Cells align on grooves Cell-repulsive pillars

Chemical Patterning:Stripe Distance and Width Effect (I.B.)

Width: 170 µm – Distance: 180 µmAdhesion selectivity

Width: 120 µm – Distance: 120 µmNo adhesion selectivity


1) Energia Libera di Superficie: componenti dispersive, polari, acide e basiche;2) Idrofobicità/idrofilicità e Struttura dell’acqua alle interfacce;3) Topologia delle superfici e dimensioni critiche per l’interazione con specie biologiche;4) Domini elettrici alle superfici

Surface Charge:Z-potenzial measurements

PHMS and SiCxOyHz

PET and a-C:H,O

La Biocompatibilità di un materiale èessenzialmente un problema di

Scienza delle Superfici ed Interfacce

⇒ Approccio Multidisciplinare:Chimica, Fisica, Matematica, Biologia, Medicina

Il punto critico:Correlazioni

Biocompatibilità-Struttura di Superficie

PARTE II.

STRATEGIE DI MICRO- E

NANOSTRUTTURAZIONE

Livelli di Correlazione Struttura-Biocompatibilità

1] Scale di tempo specifiche per processi diversi:- diffusione di ioni più veloce della diffusione di sistemi oligopeptidici e proteici, che avviene più velocemente dell’interazione con sistemi cellulari :

gerarchie temporali di eventi di interazione

2] Livelli di organizzazione diversi, con processi di auto-organizzazione bi- e tridimensionali:- processi di organizzazione della struttura dell’acqua alle superfici,- processi di aggregazione di oligopeptidi e proteine, mediati da cationi o anioni, - processi di aggregazione di “supramolecole” proteiche;

gerarchie spaziali di processi di organizzazione

Il problema:Controllare

le gerarchie spaziali di processi di organizzazione

di proteine e cellule:Micro- e Nano-Patterns

Due esempi preliminari

1) Controllo dell’interazione proteine di adesione – integrine cellulari

Proteine di adesione vengono “incluse” – con orientazione e spaziatura “obbligate”- in un monostrato fosfolipidico ancorato su una superficie

2) Uso del motore molecolare Kinesin per la “cattura” reversibile di microtubuli

Processi di ancoraggio di Kinesin su vari substrati biologici

“Cattura” reversibile di microtubuli mediante “nano-patterning” di Kinesin

su Si

Si sfrutta il comportamento “intelligente” di polimeri termoresponsiviper modulare l’accessibilità delle molecole di Kinesin per microtubuli

STRATEGIE DI MICRO- E NANOSTRUTTURAZIONE

DI SUPERFICI

2.1Nanopiattaforme

Mediante “Dephasing Processes”

Stripes and Nano-channels in DMPC:

single component films

Langmuir-Blodgett Technique(Liquid Expanded vs. Liquid Condensed Phases)

1) Supramolecular fibers in Langmuir-Blodgett (LB) conditions

O

OH

OHO

O H

O H

OO

C H 3

≡

Langmuir-Blodgett techniquequercetin palmitate (QP)

2) Fibers wrapping-up: Phase separation and nanometric spiral-like

dimyristoylphospatidylcholine(DMPC)

+DMPC: A well-known system for mimicking biological membranes

Langmuir-Blodgett Self-assembling:Liquid expanded vs. Liquid CondensedPhases

0 10 20 30 40 50 60 70 80 90 100 110

0

10

20

30

40

50

Surf

ace

Pres

sure

(mN

/m)

Molecular area (Å2)

LC

LE≡ DMPC

10 mN/m

30 mN/m

~ 1500 molecules

MICA

θ > 90°θ ≅0°

≡

Anisotropy → surface wettability, microliter cromatography, substrate for site selective reconition processes, reflective and photoluminescence optical grids…

Substrate

GrowingFront

vc

600 nm200 nm

Instability at the growing front

Transferdirection

Tran

sfer

dire

ctio

n

Nanochannels array in DMPC: LE vs. LC Phases

Ordered fibres of amphiphilic compound:

Hierarchical organisation levels

Langmuir-Blodgett Technique(Quercitine Palmitate)

gas-like30 40 50 60 70 80 90 100 110

0

10

20

30

40

Molecular area (Å2)

Pres

sure

(mN

/m)

c

b

a a

bc

LE

LC

B. Pignataro, L. Sardone and G. Marletta, Mat. Sci. Engin. C, 22/2 (2002) 177-181.

168 nm

8 nm

periodicity = 19 nmobserved fiber lateral size = 14 ± 2 nmestimated fiber lateral size = 5-8 nm Ripple phase

Minimum energy configuration depends on packingheads/tails competition and strength of the pair interaction

First level of organization

Second level

5 nm

≡

0.74 nm

Third level

Wrapping fibres:dephasing effect in a binary

system

Langmuir-Blodgett(QP in DMPC)

T = 10 °C, P = 30 mN/m, v = 5 mm/min

Qp/DMPC= 75/25 Qp/DMPC= 90/10 Qp/DMPC= 95/5

0,7 0,8 0,9 1,040

50

60

70

80

90

100

Dom

ain

surf

ace

cove

rage

%

xQP

0,7 0,8 0,9 1,040

50

60

70

80

90

100

Dom

ain

surf

ace

cove

rage

%

xQP

complete immiscibility(calculated)

experimental

- Qp and DMPC are partially miscible

B. Pignataro, L. Sardone, G. Marletta, Self-organizing fiber-likenanostructures and wrapping-up processes in LB films, Langmuir, see web ASAP.

Friction force microscopy Phase imaging

DMPC-rich phase

Qp

Dynamic SFM in attractive regime

B. Pignataro, L. Sardone, G. Marletta, Nanotechnology 14 (2003) 245–249.

Dephasing-stimulated behaviour:

Molecular nanotubes of QP in DMPC?

60°

100 nm

critical rupture bending angle Possible chirality

B. Pignataro, L. Sardone, G. Marletta, Langmuir, 19 (2003) 5912

2.2Nanopatterning

by Self-Assembling Processes


DI SUPERFICI

Self-Assembly: Il Concetto di Base “Il processo che sfrutta interazioni “deboli”

intermolecolari, sia direzionali che non direzionali, per costruire aggregati ordinati di

molecole/macromolecole/Cellule/etc…

Due funzioni di base: - Aggregazione, i.e., legamre <oggetti chimici> mediante

interazioni deboli- Strutturazione, i.e., indurre organizzazione spaziale

Il Self-Assembly è un processo multiscale

The Biology as “the” Paradigm of Multiscale Self-Assembly

The self-assembling “<objects>”

- Peptide sequences, Aminoacids- Intracellular biomolecules: DNA/RNA, proteins, etc…- Extracellular Proteins: Extracellular Matrix (ECM)- Cells, Bacteria - Biological Tissues

The ultimate scope of self-assembling in the Biological context: replicating the capability of

cell assembling (….and biological tissues)

The original characters of Biological Surfaces

- Specificity of interaction: receptors on a cell membrane, peculiar nucleotide or peptide sequences, etc…

- Variable spatial relationships: receptors within a cell membrane may “clusterize”, approaching each other, the protein domains size depend on the conformation state; etc…

- Coexistence of many interaction “motives”: electrical domains, chemical domains, hydrophobic/hydrophilic domains, etc…

- Time-dependent structure and properties: the biological surfaces/interfaces are typical “programmed” stimuli-responsive systems.

Self-Assembly: Directional vs. Isotropic Organization

The basic dicotomy:“Directional/specific” versus “Non-directional/ non-specific”

1) Structured <objects> ⇒ orienting interactions ⇒Anisotropic Organization

- Protein orientation and aggregation on surfaces,- Docking sites,- Protein patterning by direct MAPL- Cells onto patterns,- etc….

Anisotropic Organization ⇒ PATTERNING

Morphology of collagen I adlayers depending on the surface properties

LAMSUN – UNICT and CSGI, 2006

CA on PHMS ut CA on PET ut

CA on PHMS irr CA on PET irr

100 nmz= 10 nm 100 nm

z= 10 nm

100 nmz= 10 nm

100 nmz= 10 nm

Surface Macromolecular Docking Sites by Means of Self-Assembly Process

PLL-g-PEG/PEG-NTA–Ni(2+)–histag-biomoleculeM.Textor, J. Vörös and coworkers (2005)

Surface Macromolecular Docking Sites by Means of Self-Assembly

PLL-g-PEG/PEGbiotin//(Strept)avidin //aRIgG-biotinM.Textor, J. Vörös and coworkers (2005)

Molecular Assembly Patterning by Lift-off (MAPL)

• MAPL is a novel patterning technique where a specific ligand (or multiple ligand types) can be immobilized with a controlled surface density inside a defined area. The role of the ligands is to capture molecules or cells from the environment:

• - proteins in solution; • - cell transmembrane proteins such as integrins; • - DNA/RNA. • These specific types of interactions should only occur in

the designated patterns and not elsewhere ⇒ the surface between the patterns (background) is passivated

Molecular Assembly Patterning by Lift-off (MAPL)

The MAPL process is carried out in two main steps: 1) Transferring the pattern into a resist, by means of standard

photolithography (micro-MAPL) or nanoimprinting (nano-MAPL).2) The pre-patterned surfaces are chemically modified to transfer the resist

pattern into a biochemical pattern


DI SUPERFICI

2.3Microcontact Printing

(µ-CP)

Chemical Micro-contact Printing (after Whitesides and coworkers)

Cells on RGD pattern by PDMS

Microcontact Printing: The general method

Step 1 – A PDMS stamp is prepared by moulding technique, and hardened by O2-plasma treatment.

Step 2 – The stamp is inked with a thiol (EG6SH) and placed onto Au substrate (1’).

Step 3 – The stamp is peeled off, leaving “written” trace of EG6SH.

Step 4 – The printed AU substrate is immersed in a 2 mM solution of a cell-adhesive peptide (RADSc 16; 2 h) and then rinsed.

Array lineari di cellule su aree µ-CP

Ogni struttura lineare è formata da aggregati di più cellule

“Circuiti” di cellule endoteliali “patterned”mediante µ-CP

Le dimensioni dell’area “funzionalizzata” definiscono il numero di cellule che aderiscono: la connessione fra due zone è mantenuta da

due singole cellule.


DI SUPERFICI

2.4Direct writing of

cellular micropatterns by

Focused Ion Beams

Hydrophilic spots “printed” by a highly focused 20 keV Ga+ beam:

630 nm

3 µm

[SiCO2] [SiO2-εC ε ]

~ 55°~ 90°

• One-step patterning is easily achieved by Ion Beams:- Chemical changes (Low dose irradiation)- Topographical features (FIB techniques)

The irradiation “activation” is very durable (tests up toseveral months)

80 µm

STRIPES byhighly focused15 keV Ga+beam

30 µm

10 µm

Ion patterning of PHMS: 1015 cm2 Ga+ 15 keV Fibroblast Vero cells (5 hrs. Incubation time)

PHMS: PHMS: cells tend to selfcells tend to self--align parallel to the irradiatedalign parallel to the irradiated stripesstripes

Ion Beam induced cell “assembly”NHDF cells alignment onto PHMS patterned with He+ 10

keV(LAMSUN, 2007)

The stripe width is 30 µm – pitch 90 µm

Ion Beam-induced cell “assembly”Actin Filament Self-Assembly inside the cells within the

irradiated regions (LAMSUN, 2007)


DI SUPERFICI

2.5Direct writing of

Protein nanopatterns by

Focused Ion Beams

ToF-SIMS imaging

C2H5 Fe Au TIC

a b

cd

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

SAu

FIB patterning of Thiol SAM

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

S

OH

SAu Ions dose = a>b>c>d

C2H5 Fe Au TICAu

ToF-SIMS imaging

OH

S

O H

S

OH

S

OH

S

OH

S

OH

S

O H

S

OH

S

OH

S

OH

S

OH

S

OH

S

O H

S

O H

S

OH

S

OH

S

OH

S

OH

S

O H

S

O H

S

OH

S

OH

SAu

Fe Fe Fe Fe Fe

substrate

Thiol solution(10-5 M ÷ 10-3 M)

NN N

SH

+ + FeSO4

OH

S

O H

S

OH

S

OH

S

OH

S

OH

S

O H

S

OH

S

OH

S

OH

S

OH

S

OH

S

O H

S

O H

S

OH

S

OH

S

OH

S

OH

S

O H

S

O H

S

OH

S

OH

SAu

+

OH

S

O H

S

OH

S

OH

S

OH

S

OH

S

O H

S

OH

S

OH

S

OH

S

OH

S

OH

S

O H

S

O H

S

OH

S

OH

S

OH

S

OH

S

O H

S

O H

S

OH

S

OH

SAu

C2H5 Fe Au TIC

Aminoacids fragmentof

Lactoferrine

Fe Fe Fe Fe Fe

ToF-SIMS imaging

OH

S

O H

S

OH

S

OH

S

OH

S

OH

S

O H

S

OH

S

OH

S

OH

S

OH

S

OH

S

O H

S

O H

S

OH

S

OH

S

OH

S

OH

S

O H

S

O H

S

OH

S

OH

SAu

Fe Fe Fe Fe Fe

ODT SAM

Ion-beam or tip patterning

MPTP/MB assembly

Ni2+

C4H7+ Ni+ Ni(MPTP)+ Ni(MPTP)Au+

Surface reaction on a patterned monolayer

ToF-SIMS mass resolved images

Micro- and nanopatterning by Self-Assembly:

Anisotropic vs. Isotropic OrganizationThe basic dicotomy:

“Directional/specific” versus “Non-directional/ non-specific”

2) The interactions among isotropic <objects> yield isotropic ordering? ⇒2.1) YES: - Ordered packing for polymer nanoparticles, metallic colloids, etc…2.2) NO: - Anisotropic patterns for bacteria, cells, etc…

2.5Patterning using

Micro- and Nano-Colloids

Nanopatterned polysiloxanesurface

CCACN: Colloidal Crystal-Assisted Capillary

Nanofabrication (Chen, Adv. Mater., 2003)1. Two substrate vertical deposition procedure: immersion of two hydrophilic substrates in a suspension of carboxylated PS microspheres

2. solvent evaporation and formation of confined three-dimensional (3D) colloidal crystals

3. A solutions containing the desired species wicks into the interstices of the colloidal crystals through capillary suction

4. removal of colloids by sonication and nanopatterned 2D array

1a. spin coating of hydrophobic PHMS thin films

1b. O2 plasma (133 Pa, 100 Watts, 60 sec.) to convert the films into hydrophilic SiO2-like phases J. Mat. Sci.: Mat. in Med., 2003

3. Spin coating of a second PHMS layer (various thickness and solvent evaporation kinetics)

Our implementation:

Self-Assembly of carboxylated-polystyrene beads(200 nm diameter) on (plasma-treated) PHMS

LAMSUN – UNICT and CSGI 2005

Self-Assembly of carboxylated-polystyrene beads(200 nm diameter) on (plasma-treated) PHMS

LAMSUN – UNICT and CSGI 2005

Hydrophilic nanopores in hydrophobic PHMS

Process: spin coating of hydrophobic PHMS and sonication step

1 µm

C. Satriano, G.M. Messina and G. Marletta, J. Mater. Sci. Eng.C, 26 (2006)

Z range= 10 nm1 µm

209 nm diameter

Z range= 10 nm

1 µm

362 nm diameter

Z range= 10 nm1 µm

489 nm diameter

3D- representation of nanoflowers and nanopores

2.4 nm 2.6 nm 3.6 nm

2.6Patterning Proteins

by Polyelectrolytes

(positively- vs. negatively-charged surfaces)

Engineering at molecular level -combination of LbB and LB methods

Local surface patterning by microstamping•• Result of stampingResult of stamping

• Master

Antibody of C-reactive protein (a-CRP) on PSS/CRP sub-layer

PATTERNED PROTEIN BILAYER BY µCP ONTO Si SUBSTRATE(“INK”: PDDA)

PDDApoly(diallyldimethylammo

nium) chloride:

(

N

CH2 CH2

CH3 CH3

+

)

ConclusionsIon Beams are capable to produce complex modification

of several Surface Properties, as Surface Free Energy, topographical features, specific chemistry, charge state, etc…

In particular, Ion-Irradiated Surfaces appear to be very attractive for cell adhesion studies, as they seem to act through interplay of several properties simultaneously

THE NEXT FRAMEWORK

How the specific Time and Spatial Scales of the different properties influence the cell and

bacteria response factors?

Superfici Biocompatibili:Un mondo ancora nascosto!

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