NANOPARTICLES FOR DRUG DELIVERY:NANOPARTICLES FOR DRUG DELIVERY:

THE SMALLER, THE BETTER ?THE SMALLER, THE BETTER ?

Gurny R., Pourtier M., Vargas A., Delie F. Gurny R., Pourtier M., Vargas A., Delie F.

Department of Pharmaceutics and BiopharmaceuticsDepartment of Pharmaceutics and Biopharmaceutics

School of Pharmaceutical Sciences, University of Geneva, University of School of Pharmaceutical Sciences, University of Geneva, University of

LausanneLausanne

NanoparticlNanoparticleses

= NPs= NPs

HOW SMALL ARE HOW SMALL ARE

NANOPARTICLESNANOPARTICLES

??

CURRENTLY USED SMALL PARTICLES AS CURRENTLY USED SMALL PARTICLES AS

THERAPEUTIC VECTORSTHERAPEUTIC VECTORS

0 100 200 300 400 500 600 700 800 900 1000 10000 nm

MicroparticlesNanoparticles

Several studies on particles < 1000 nm

100100

NANOPARTICLES ARE EASY TO NANOPARTICLES ARE EASY TO

PREPAREPREPARE

1 m

Mean size: 300 nm

Gurny et al., Drug Dev. Ind. Pharm (1981)

VITAL PARAMETERS FOR NPs FOR VITAL PARAMETERS FOR NPs FOR

BIOMEDICAL APPLICATIONSBIOMEDICAL APPLICATIONS

Loading

Biodistribution

Precise control of the size

Release profile of the

drug

Elimination of NPs

Shakweh et al., Eur. J. Pharm. Biopharm. (2005)

Mean size: 310 nm

SOME HISTORICAL ASPECTSSOME HISTORICAL ASPECTS

1 m

1970 1980 1990 2000 2010 2020

Microparticles

Nanoparticles

1 m

Picoparticles ?

RESEARCH ARTICLES ON RESEARCH ARTICLES ON NANOPARTICLES NANOPARTICLES

Source: SciFinder Scholar

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

50000

(1975-1980)

(1981-1985)

(1986-1990)

(1991-1995)

(1996-2000)

(2001-2005

Year

Nu

mb

er o

f p

ub

lica

tio

n i

ncl

ud

ing

th

e te

rm

"nan

op

arti

cles

"

350

300

250

200

150

100

50

0 Nu

mb

er o

f ci

tati

on

s in

clu

din

g t

he

term

s "n

ano

par

ticl

es a

nd

can

cer"

1975-1980

1981-1985

1986-1990

1991-1995

1996-2000

2001-2005

SMALL PARTICLES ? WHY ? FOR SMALL PARTICLES ? WHY ? FOR

WHAT ? WHAT ?

Minimize embolization in case of parenteral

administration

Increase the release surface

Increase the uptake (passage across biological

barriers)

Facilitate sterilization

% in class

Size (nm)

50

100

200 600 800 1000400

CHARACTERIZATION OF SIZE CHARACTERIZATION OF SIZE

AND POLYDISPERSITYAND POLYDISPERSITY

Size distribution

% in class

Size (nm)

50

100

200 400 600 8001000

Mean size: 600 nm

Dispersity

Monodisperse: PI < 0.1

600

Monodisperse

Polydisperse

600

Polydisperse: PI > 0.1

AVAILABLE METHODSAVAILABLE METHODS

• Static and dynamic light scattering (SLS, Static and dynamic light scattering (SLS, DLS)DLS)

www.ibmb.uni.wroc.pl/ liplip/zeta.jpg http://www.icmse.cartuja.csic.es/servicios/sema.gif

http://gene.concordia.ca/csfg/images/equip/auc.jpg

www.wyatt.com/solutions/hardware/eclipse.cfm

• Scanning electronic microscopy (SEM)Scanning electronic microscopy (SEM)

• Analytical ultracentrifugation (ANUC)Analytical ultracentrifugation (ANUC)

• Field flow fractionation (FFF)Field flow fractionation (FFF)

DATA OBTAINEDDATA OBTAINED

SLS/DLS SEM ANUC FFF

Rapid

All sizes >50 nm

Direct

Less influenceof extremes

Large sample

Population Separation (DLS)

Non adapted forvery polydispersedsamples> 2 m

Time consuming

Influence of thepreparation

Complexity of the conversion: Turbidity / size

Difficult

> 1 m

0.0

51.0x10

52.0x10

53.0x10

0 5 10 15 20 25

Mol

ar M

ass

(g/m

ol)

Time (min)

Molar Mass vs. Time BSA filt__20041013__448_04.adf

Fractions collection

Mild method

THE BEST METHOD ?THE BEST METHOD ?

Determination by light scattering:

Size average: 313.7 nm

Polydispersity: 0.093 0.017

… real size ?!

SAFETY AND CHARACTERIZATION SAFETY AND CHARACTERIZATION CONCERNSCONCERNS

…… What are the critical physical and chemical What are the critical physical and chemical

properties, including residual solvents, properties, including residual solvents, processing variables, impurities and excipients?processing variables, impurities and excipients?

How do physical characteristics impact product How do physical characteristics impact product quality and performance?quality and performance?

What are the standard tools used for this What are the standard tools used for this characterization? characterization?

FDA Perspective on Nanomaterial-Containing FDA Perspective on Nanomaterial-Containing Products Products

Nanobusiness Conference, May 2005Nanobusiness Conference, May 2005

DETERMINATION OF SIZE DETERMINATION OF SIZE

… real size ?!

ACCURATE DETERMINATION OF ACCURATE DETERMINATION OF

OTHER CHARACTERISTICS OTHER CHARACTERISTICS

!

?

The contribution of these parameters is

of great importance in life sciences

SizeSize

Charge Charge

Hydrophobicity Hydrophobicity

Adsorption of Adsorption of blood components blood components on nanoparticles on nanoparticles

= f(time)= f(time)

NP size: 312 nm, 2-D PAGE

Allémann et al; J. Biomed. Mater. Res. (1997)

IN VITRO RELEASEIN VITRO RELEASE

Allémann et al; Pharm. Res. (1993)Allémann et al; Pharm. Res. (1993)

671 nm ()

274 nm ()

303 nm ()

BIOLOGICAL ACTIVITY ON ISOLATED BIOLOGICAL ACTIVITY ON ISOLATED TUMOUR CELLS =f (SIZE)TUMOUR CELLS =f (SIZE)

Konan-Kouakou et al; J. Control. Rel. (2005)Konan-Kouakou et al; J. Control. Rel. (2005)

370 nm

167 nm Free

Biodegradable particles with well defined Biodegradable particles with well defined sizessizes

0 100 200 300 400 500 600 700 800 900 1000 2000 nm

SEM: Magnification: x 10

000(5 to 15 KV, 5 to 39 mm)

1 m 1 m

1 m1 m 1 m

Polymer: poly(D,L-lactide-co-glycolide) acid (PLGA)

Pourtier M. & al., unpublished data

Biological response = f(size, surface Biological response = f(size, surface properties)properties)

?

Interaction of NPs with biological surfacesInteraction of NPs with biological surfaces

Caco-2 = human colon carcinoma cell line

Culture in plates

Fluorescent particles: different sizes

++

Uptake ?Uptake ?

Quantitative

Fluorescence spectroscopy

Qualitative

Confocal microscopy

Incubation

BIODISTRIBUTION=f(SIZE) ?BIODISTRIBUTION=f(SIZE) ?

I.V. administrationI.V. administration

PHAGOCYTOSISPHAGOCYTOSIS MECHANICAL FILTRATIONMECHANICAL FILTRATION

Macrophage

Blood vessel

Interstitial space

I…....I.....I....I....I...I...I..I.I.I…....I.....I....I....I...I...I..I.I.I…....I.....I....I....I...I...I..I.I.I…....I.....I....I.1…………………………10………………………..100………………………1000…………………………nm

FENESTRAE IN BLOOD FENESTRAE IN BLOOD CAPILLARY WALLSCAPILLARY WALLS

No fenestration

400 to 800 nm

Tumours

80 to 1400 nmInflammation

Skeletal and cardiac muscles Lung

Skin

Kidney

Small intestine Salivary glands

Liver SpleenBone

marrow

Blood brain

barrier

1.8 to 2.0 nm 40 to 60 nm Up to 150 nm

Blood Blood brain brain

barrierbarrier

Skeletal and Skeletal and cardiac muscles cardiac muscles Lung Lung

Skin Skin

Kidney Kidney

Small Small intestine intestine Salivary Salivary glandsglands

LiverLiver SpleenSpleenBoneBone

marrowmarrow

1.8 to 2.0 nm1.8 to 2.0 nm 40 to 60 nm40 to 60 nm Up to 150 nmUp to 150 nm

BIODISTRIBUTION OF BIODEGRADABLE BIODISTRIBUTION OF BIODEGRADABLE NPNP

Data taken from Fang et al; Eur. J. Pharm. Sci. (2006)

0

1

2

3

4

5

6

Blood Liver Spleen Kidney

% in

ject

ed d

ose

/ g

tis

sue

243 nm

171 nm

80 nm

Cyanoacrylate- MePEG (5000) NP

Biodistribution in mice

1 hour after administratio

n

Internalisation of anti-HER2 nanoparticles in SKOV-3 cells

D DD

D

Normal vessels D = Drug

PARENTERAL ADMINISTRATION OF PARENTERAL ADMINISTRATION OF NANOPARTICLESNANOPARTICLES

= Nanoparticle

D DD

D

DD

D

DD

D

D = Drug

= Nanoparticle

D

D

D D

D

DD

DDD

D

D

D

D = Drug

= Nanoparticle

Fenestrated vessels

Fenestrated vessels

Solid tumours

Folkman, J. Scientific American 1996, 275 (3):150-154

NANOPARTICLES AND CANCERNANOPARTICLES AND CANCER

Small nanoparticles can get into tumoural

tissues

0

1

2

3

4

Blood Liver Spleen Tumour

% in

ject

ed d

ose

/ g

tis

sue

243 nm

171 nm

80 nm

Data taken from Fang et al; Eur. J. Pharm. Sci. (2006)

Biodistribution in S-180 tumour-

bearing mice 6h after I.V

administration

NANOPARTICLES AND CANCERNANOPARTICLES AND CANCERPoly methoxypolyethyleneglycol cyanoacrylate-co-n-hexadecyl cyanoacrylate NPs

SO, NP SIZE INFLUENCES BOTH THE SO, NP SIZE INFLUENCES BOTH THE CLEAREANCE AND THE CLEAREANCE AND THE

BIODISTRIBUTION, BUT…BIODISTRIBUTION, BUT…

Precision in size measurements ?Precision in size measurements ?

Polydispersity of batches? Polydispersity of batches?

Some case Some case studies…studies…

From the abstract

We have prepared hydrogel nanoparticles of polyvinylpyrrolidone of a size less than 100 nm diameter with precise size distribution…

…… Increasing the surface hydrophobicity as well as particle sizecan increase the RES uptake of these particles.

SIZE DETERMINATION BY QUASI-ELASTIC LIGHT SCATTERING

…all formulations appeared to be very homogenous irrespective of their composition ……….. their narrow size distribution.

From the abstract

…. We found that small diameter (18 nm) … showed the most favorable biological behavior … … and diameter of the nanoparticle play important roles ….

Size determined by hydrodynamic Size determined by hydrodynamic light scatteringlight scattering

From the abstract… the biodistribution properties of the PLGA/PLGA-PEG nanoparticles are also influenced by the size of the nanoparticles …

ACKNOWLEDGMENTSACKNOWLEDGMENTS

Angélica VargasAngélica VargasMarie PourtierMarie PourtierFlorence DelieFlorence Delie