Amir Saamaan Fattahi presented on photo-responsive polymers. He discussed how photo-responsive polymers contain photo-responsive moieties that can undergo reversible or irreversible changes when exposed to light. Reversible moieties like azobenzene and spiropyran can cycle between isomers with light, while irreversible moieties like o-nitrobenzyl undergo cleavage. Photo-responsive polymers can be used for applications like drug delivery, actuators, and adhesives by integrating these light-sensitive units and manipulating the polymers with light. Future areas of research include using these materials for phototherapy and improving drug delivery methods with light-triggered release.

1. Presentation by:
Amir Saamaan Fattahi
Ph.D student of pharmaceuticalnanotechnology
Shiraz school of pharmacy
Photo-responsive polymers
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2. Introduction
 The photo-responsive polymers always consist of photo-responsive moieties and
bulk polymer.
 In this review, we mainly focus on the discussion of photo-responsive moieties,
which can be divided into irreversible and reversible moieties.
 For irreversible moieties, like o-nitrobenzyl and coumarinyl, can undergo photo-
induced bond cleavage and thus this transition is one-off.
 Whereas the reversible moieties, such as azobenzene and spiropyran, can give
rise to photo-responsive cyclical isomerization between isomers when treated by
specific light.
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3.  Photo-responsive polymers are a special part of stimuli-responsive materials,
which use light irradiation to change. Typically, the light that is being used is in
the ultraviolet (UV), visible (vis) or infrared (IR) region.
 While UV light has the highest energy, vis and IR light are more attractive for
solar energy and biomedical research, because vis and IR light responsive
polymers fit more to the solar spectrum, show less damage and can penetrate
deeply into tissue.
 Examples of such polymers include conjugated
polymers, homopolymers, telechelic polymers, block copolymers, dendritic
polymers, and supramolecular polymers.
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Introduction

4. Photo-responsive polymers are particularly
interesting because of the following reasons:
 Polymers have advanced and hierarchical structures that offer many possibilities
to integrate switchable units.
 Different to switchable small molecules, switchable polymers can have
cooperative or collective motions.
 Polymers in general show good processability.
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Construction of photo-responsive polymers by introducing
photo responsive moieties to bulk polymers by:
(A) copolymerization
(B) modification as side chain.

6. Irreversible photo-responsive moieties
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7. Reversible photo-responsive moieties
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9. Characteristic features of the PRPs discussed in this
chapter
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10. Effect of the photo-responsive moieties onto the
behavior of micelles in solution under irradiation
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11. Top 3 future applications
 1. Phototherapy
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 2. Actuators:

12.  3. Adhesives
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13. Applications of PRPs in Solution
Example 1
Multiple micellization process: (a) schematic representation of the MMP,
chemical structure of PEO-b-P(ETEGA-r-NBA) and changes in the micellar
hydrodynamicdiameter with temperature and light irradiation; 8/9/2022
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14. Example 2
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15. Example 3
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16. Photosensitive moieties in the main chain
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17. Functionalized Stimuli-Responsive Nanocages
from Photocleavable Block Copolymers
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18. Concurrent Block Copolymer PolymersomeStabilization
and Bilayer Permeabilization by Stimuli-Regulated
“Traceless” Crosslinking
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19. Photo-responsive delivery
Schematic illustration of NIR-induced release mechanism of water-
confined polymeric particles. Exposure to laser light resonant with
vibrational absorption of water (i.e., 980 nm) induces photothermal
heating of confined water pockets present in hydrated microparticles.
The resulting localized heating facilitates the diffusion of encapsulated
model drugs out of the particles.
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20. combination of NIR-based thermotherapy and triggered
chemotherapy (thermo chemotherapy)
 Recently, Dai and coworkers have reported a gold-nano-shell-coated cholesteryl succinyl silane (CSS) nano
micelle loaded with both DOX and Fe3O4 magnetic nano micelle (CDF–Au-shell nano micelle) to combine
magnetic resonance (MR) imaging, magnetic-Field guided drug delivery, light-triggered drug release, and
photothermal therapy.
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21.  integrated polydopamine (PDA)-coated magnetite nanoparticles and PAMAM dendrimers
to synthesize novel and multifunctional nanoplatforms.
 The designed PAMAM dendrimer G 5.0 functionalized nanocarriers exhibited a high drug-
encapsulating capacity for doxorubicin hydrochloride, and were successful applied in the
photo- and chemothermal treatment of the human hepatoma HepG2 cell line (liver
cancer cells), even at lower nanoparticle concentrations.
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22. PRPs for drug delivery applications: limitations and
future trends
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23. Example 2
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24. Application of PRPs at surfaces
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25. Application of PRPs in thin films
Example 1
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26. Example 2
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27. Application of PRPs networks: gels and hydrogels
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28. Building nanostructures with light: thinking
outside the box
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29. Fabrication of Complex Three-DimensionalPolymer Brush
Nanostructuresthrough Light-MediatedLiving Radical
Polymerization
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31. Conclusions
 Firstly, we have focused on self-assembly and dis-assembly of the light-
responsive block copolymers in dilute solutions to form or to disintegrate
micellar structures.
 classified the different systems based on the reversible or irreversible character
of their photo-induced structural or morphological changes. We have also
discussed systems where light is used to stabilize the micellar structure by
crosslinking.
 The effect of light irradiation is presented for each photo-responsive group and
the reversible character of the photochemical reaction is stated. The design of
each PRP is described emphasizing the location of the photo-responsive group:
as side-groups, incorporated in the main chain or included as a single group at
the block junction.
 Finally, we have discussed the use of photo responsive polymers to make
interesting stimuli-responsive gels.
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32. Reference
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