Bimodal immunoradiotherapy

using thermoresponsive

polysaccharide-based polymers:

Are they able to promote

immune system?

Lenka Loukotová (Ph.D. student)

Institute of Macromolecular Chemistry, Prague, Czech Republic

ChemotherapyRadiotherapy

Immunotherapy

Hormone Therapy

Stem Cell Transplant

Current types of cancer treatment

Surgery

ChemotherapyRadiotherapy

Immunotherapy

Hormone Therapy

Stem Cell Transplant

Current types of cancer treatment

Surgery

Immuno-radiotherapy

Treatment principle of immunoradiotherapy

• polymer forms a depot at the injection site - thermoresponsivity

• radiation kills tumor cells (including cells protecting tumor from immune

response)

• immunomodulator enhances following immune response against remaining

tumor cells and metastasis

Polymer drug design

20 °C 37 °C

– therapeutic radiation – yttrium-90(III)β– decay, T1/2 = 64.1 hDOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid

– thermoresponsivity – poly(2-isopropyl-2-oxazoline) graftsbiocompatibility, radioresistivity1

– immunomodulatory polysaccharidenon-specific immune activation, biodegradable

1 O. Sedlacek, P. Cernoch, J. Kucka, R. Konefal, P. Stepanek, M. Vetrik, T.P. Lodge, M. Hruby, Thermoresponsive polymers for nuclear medicine: Which polymer is the best?, Langmuir 32 (2016) 6115–6122.

β-Glucan from Auricularia auricula-judae

1. Synthesis- extraction of β-glucan from Auricula auricula-judae

- anticancer properties1

- grafting of β-glucan by polyoxazoline, chemical modification

- radiolabeling with yttrium-90(III)

Auriculaauricularia-judae

1 M. Zhaocheng, J. Wang, L. Zhang, Structure and chain conformation of β‐glucan isolated from Auricularia auricula‐judae, Biopolymers 89 (2008) 614–622.

β-Glucan-graft-POX

2. Physico-chemical characterization

- dynamic light scattering – cloud point temperature –tuned to be appropriate for the depot formation

- β-glucan-graft-polyoxazoline (Mn,graft = 2500 Da, maximum achievable grafting density),c = 1 mg/mL in PBS

T = ?

10 20 30 40

0

500

1000

1500

2000

2500

Rh

(nm

)

temperature (°C)

CPT

L. Loukotova et al., Thermoresponsive β-glucan-based polymers for bimodal immunoradiotherapy–Are they able to promote the immunesystem?, J. Control. Release 267 (2017) 78–91.

3. In vivo experiments - prior successful and promising in vitro experiments

(cellular uptake, oxidative burst of the leukocytes, production of TNF-α…)

Antitumor efficiency - C57BL/6N mice with murine lymphoma EL4- groups:1) Control

- no treatment

2) IMMUNO- β-glucan-graft-POX

1 mg/mouse

3) RADIO- POX with 90Y

0.7 mg/4 MBq/mouse

4) IMMUNORADIO- β-glucan-graft-POX with 90Y

1 mg/4 MBq/mouse

β-Glucan-graft-POX

L. Loukotova et al., Thermoresponsive β-glucan-based polymers for bimodal immunoradiotherapy–Are they able to promote the immunesystem?, J. Control. Release 267 (2017) 78–91.

3. In vivo experiments

Antitumor efficiency

0 15 30 45 60

0

20

40

60

80

100

su

rviv

ing

mic

e (

%)

days after application

control group

IMMUNO

RADIO

IMMUNORADIO

0 5 10 15 20

0

2

4

6

8

control group

IMMUNO

RADIO

IMMUNORADIO

Va

ve

rag

e (

mL

)

days after application

IMMUNO – β-glucan-graft-POXRADIO – POX with 90YIMMUNORADIO – β-glucan-graft-POX with 90Y

β-Glucan-graft-POX

L. Loukotova et al., Thermoresponsive β-glucan-based polymers for bimodal immunoradiotherapy–Are they able to promote the immunesystem?, J. Control. Release 267 (2017) 78–91.

Study design

– therapeutic radiation – yttrium-90(III)

– thermoresponsivity – polyoxazoline grafts

– immunomodulatory polysaccharide

1. Influence of various polysaccharides on the treatment success in vivo

2. Detailed study of the synergistic effect of both therapies

κ-Carrageenan from Kappaphycus alvarezii

1. Physico-chemical characterization

- dynamic light scattering – κ-carrageenan-graft-POX (Mn,graft = 1950 Da),c = 1 mg/mL

Kappaphycusalvarezii

κ-carrageenan

10 20 30 40 50 60

102

103

104

105

106

in 0.15 M NaCl

in PBS

De

rive

d C

ou

nt

Ra

te (

a.u

.)

Temperature (°C)

κ-Carrageenan-graft-POX

1. Physico-chemical characterization

- dynamic light scattering – κ-carrageenan-graft-POX (Mn,graft = 1950 Da),c = 1 mg/mL

gel solution

10 20 30 40 50 60

102

103

104

105

106

in 0.15 M NaCl

in PBS

De

rive

d C

ou

nt

Ra

te (

a.u

.)

Temperature (°C)

κ-Carrageenan-graft-POX

1. Physico-chemical characterization

- dynamic light scattering – κ-carrageenan-graft-POX (Mn,graft = 1950 Da),c = 1 mg/mL

gel solution above CPT

10 20 30 40 50 60

102

103

104

105

106

in 0.15 M NaCl

in PBS

De

rive

d C

ou

nt

Ra

te (

a.u

.)

Temperature (°C)

Acknowledgement

Martin Hrubý

Mariia Rabyk

Jan Kučka

Rafal Konefal

Olga Janoušková

Kristýna Venclíková

Anita Hocherl

Luděk Šefc

Věra Kolářová

Pavla Francová

Petr Páral

Tomáš Heizer ….