NANOTECHNOLOGIES: NANOTECHNOLOGIES:

THE NEW GENERATION OF THE NEW GENERATION OF

MEDICINEMEDICINE

Dr Mariano Dr Mariano

LicciardiLicciardi

NANOTECHNOLOGIES › NANOMEDICINENANOTECHNOLOGIES › NANOMEDICINE ==

NANOPHARMACEUTICALSNANOPHARMACEUTICALSNANOPHARMACEUTICALS represent an emerging field where the

nanoscale element may refer to either the size of the drug particle or to a

therapeutic delivery system. These therapeutic systems may be defined

as a complex system consisting of at least two components, one of which

is the active ingredient. In this field the concept of nanoscale is the range

from 1 to 500 nm.

NANOPHARMACEUTICALSNANOPHARMACEUTICALShave the finality to optimize drug delivery, bioavailability and

in general increase the efficacy of already known drug molecules increase the efficacy of already known drug molecules

respect traditional dosage formsrespect traditional dosage forms in terms of:

- - chemical stabilitychemical stability,, - - promote selective drug promote selective drug accumulation into the target accumulation into the target organs or cellsorgans or cells,,- - decrease administered dosedecrease administered dose,,- decrease side and toxic effects,decrease side and toxic effects,- allow administration through - allow administration through all administration routesall administration routes..

Our research is focused on the preparation and characterization of bicompatible polymers useful to prepare nanopharmaceutical devices for pharmaceutical and biomedical applications.

In particular our interest is addressed to some synthetic polyaminoacids, such as -poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) and -polyaspartylhydrazide (PAHy).

Both polymers have attracted great interest, since they are highly water soluble, non toxic, non antigenic, non teratogenic and easily produced in large quantities and at low cost.

In particular, the biocompatible polymers that we have investigated, have been used as starting materials to prepare:

- macromolecular macromolecular

prodrugs, prodrugs,

- polymeric micelles, polymeric micelles,

- polymer-protein polymer-protein

complexes,complexes,

- polycations for gene polycations for gene

therapy therapy

-nanoparticlesnanoparticles

-poly (N-2-hydroxyethylaspartamide) (PHEA)

HH

HH2

H2 H2

H2

H H

H

H

H2 H2

H2

H2

H2

O

OC

NCC

O

CC

CHN

CO

O

CHC

O

NC

OO

CO

OC

CHCN

CCHCN

CCH

CH2

NH

CH2

C

O

NH

CH2

C

OH

NHC

CO

OH

CCH2

HN

HNCH2

CH2HO

2

H

HH2

H2 H2

H2

H H

H

NH

NH2

O

OC

NCC

O

CC

CHN

CO

O

CHC

O

NC

OO

CO

OC

CHCN

CCHCN

CCH

CH2

NH

NH

HNNH2

NH2

HN

NHH2N

-polyasparthylhydrazide (PAHy)

Drug

Spacer

Targeting group(Active Targeting)

Polymeric Backbone (carrier)

In macromolecular conjugates, active agents are covalently linked to hydrophilic polymeric carrier by hydrolizable bonds or spacers, so that the hydrolysis of active agent/polymer linkage is necessary to its release and to obtain the effect. The main advantage of these systems is constituted by their ability to efficiently protect linked drug molecules, to increase water-solubility, to increase bioavailabity and modulate drug targeting and biodistribution.

1 nm ‹ d ‹ 20 1 nm ‹ d ‹ 20

nmnm

Alclofenac, Naproxen,Ketoprofen Ibuprofen, Diflunisal, Indometacin,

Biphenilacetic acid

Amantadine,Aciclovir, Ganciclovir, Zidovudine

Citarabine

Taxol

Gemcitabine

Examples of drugs linked to our polymers

RESULTSRESULTS Increase water solubility and chemical stability

of TaxolPHEA-2’-SUCCINYLTAXOL

CONJUGATE

3'2'

1716

1 2

3

20

45

67

19

8

91011

18

12

13

14

O

O

CH3

OO

CH3CH3

OH

O

CH3O

O

O

NH

O

O

O

O

CH3

OH

O

O

CH3 O

H

OH OH

OH

OH OH

OH

Promote passive targeting to a specific organ: liver

Eur. J. Pharm. Biopharm. 58, 151 (2004)

RESULTSRESULTS

Promote selective drug Promote selective drug targeting (mediated by targeting (mediated by oxytocin receptors) oxytocin receptors) inside ovarian and inside ovarian and breast tumorsbreast tumors

PEG

TAXOL

OXYTOCIN

Eur. J. Pharm. Biopharm. 66 (2007) 182

POLYMERIC MICELLESPOLYMERIC MICELLESPolymeric micelles are colloidal systems obtained by self-assembling of

amphiphilic copolymers above critical aggregation concentration (CAC). In

the polymeric micelle the drug can be incorporated by physical or upon

chemical linking to polymeric surfactant. The ability of polymeric micelles to

promote drug absorption is correlated to the increase of cell membrane

crossing, thus strongly improving drug bioavailability.

10 nm ‹ d ‹ 200 10 nm ‹ d ‹ 200

nmnm

PHEA-PEG-C16

n

HH2

H2 H2

H2

H H

H

H

H2

H2

H2

H2

OH

C

CH2

CHC

N CCH C

N CCH

CO

O CNHO

O

CN

O

CCH

OO

CNH

CH2

NCH

CC

NH

O

CC N

CO

CH2

HN

O

C

OH

C

COCH2CH2

CH3(CH2)15NH

CH3(CH2)15

OCH3

HN

OCH2CH2CH3On

H2

H2C

C

CH3

H

HH2

H2 H2

H2

H H

H

H2N

CH2

CHC

N CCH C

N CCH

C

HNNH2

O

O CNHO

O

CN

O

CCH

OO

CNH

NH2

NCH

CC

NH

O

CC N

CO

O

(CH2)15

PAHy-PEG-C16

0

5

10

15

20

25

30

35

0,25 1 5 24 72 144tempo (ore)

%d

pm

/g t

essu

to ±

DS

PHEA PHEA-PEG2000PHEA-PEG5000 PHEA-PEG2000-C16PHEA-PEG5000-C16

TUMOR DISTRIBUTION PROFILE

J. Control. Release, J. Control. Release, 89, 285 (2003)89, 285 (2003)

PHEA-PEG-C16 micelles: slow and progressive PHEA-PEG-C16 micelles: slow and progressive

tumor accumilation after parenteral administrationtumor accumilation after parenteral administration

in rat.in rat.

TEM images of Tamoxifen-loaded PHEA-PEG-C16 micelles at 20000x (a) and 50000x (b) magnifications.

TEM images of Tamoxifen-loaded PHEA-PEG-C16 micelles at 20000x (a) and 50000x (b) magnifications.

Macromol. Biosci. 4, (2004) 1028

INCREASED TAMOXIFEN SOLUBILITY AND

CELL UPTAKE

Polymer-protein complexesPolymer-protein complexesPolymeric complexes are nanodevices formed by synthetic copolymers properly designed in order to complex small molecules or macromolecules by physical interactions. Colloidal resulting systems are able to strongly stabilize and protect peptide and protein molecules, allowing their administration for different administration routes.

10 nm ‹ d ‹ 250 10 nm ‹ d ‹ 250

nmnm

Application fields include successful oral delivery of peptides, proteins and vaccines.

RESULTS AFTER ORAL ADMINISTRATION OF INSULIN COMPLEXES

International Application n. PCT/IT/2008/000376

Patent N. RM2007A000327

GOLD MEDAL AT SALON

INTERNATIONAL DES INVENTIONS

GENEVE 2008

0

20

40

60

80

100

120

140

160

180

0 1 2 3 4 5 6 7 8 9

time (h)

he

ma

tic

glu

co

se

lev

el

mg

/dl

insulin sc insulin os insulin/P1 os P1 os

Insulin-polymer complex

INTERPOLYECTROLITE COMPLEXESINTERPOLYECTROLITE COMPLEXESPolyplexes (InterPolyElectrolyte Complexes, IPECs) are obtained by electrostatic interaction between cationic polymers (positively charged) and genetic material (such as plasmids or nucleic acid based drugs, negatively charged);

these systems are able to condense genetic material (until to colloidal size), in order to make possible its introduction into cells and besides they protect DNA from nuclease degradation improving transfection efficiency.

50 nm ‹ d ‹ 500 50 nm ‹ d ‹ 500

nmnm

RESULTS

PHEA and PAHy cationic copolymers have been showed to be non toxic and able to transfect plasmid to cells in vitro

J. Control. Release 131 (2008) 54

Nanomedicine 4(2) (2009) 291

Nanomedicine 5(2) (2010) 243

Nanoparticles

Polymeric nanoparticles are drug loaded nanomatrices obtained by chemical or physical crosslinking of properly derivatized synthetic (PHEA, PAHy) or natural (polysaccarides) polymers.

Nanoparticles can incorporate high amount of active molecules (high drug loading capacity) and control drug release rate and biodistribution.

10 nm ‹ d ‹ 500 10 nm ‹ d ‹ 500

nmnm

PREPARATION OF POLYMERIC NANOPARTICLES BASED ON PHEA COPOLYMERSRESULTS:

Stealth nanoparticles based on PHEA copolymers allowed successfully to escape reticulo-endotelial system reducing non productive effects and immunitary response.

Biomacromolecules 7 (2006) 3083

macrophages

PEG shell

CONCLUSIONSCONCLUSIONS

Nanotechnologies represent today a very promising approach to design and obtain drug and gene delivery systems with the aim to solve the problems connected with the traditional dosage forms.

In the Laboratory of Biocompatible Polymers of the University of Palermo different nanotechnologies have been produced for drug and gene delivery;

These nanotechnologies have been successfully proposed in nanomedicine, diagnostics and cosmetics.

We hope that research in this field We hope that research in this field

could go on obtaining more and morecould go on obtaining more and more

promising results.promising results.