Submit to Polymers Review for Polymers Propose a Special Issue

Journal Browser

► Journal Browser

Stimuli Responsive Polymers

Special Issue Editors
Special Issue Information
Keywords
Related Special Issue
Published Papers

A special issue of Polymers (ISSN 2073-4360).

Deadline for manuscript submissions: closed (1 February 2018) | Viewed by 84622

Share This Special Issue

Special Issue Editor

Prof. Dr. Charles-André Fustin

E-Mail Website
Guest Editor

Institute of Condensed Matter and Nanosciences (IMCN), Division of Bio and Soft Matter (BSMA), Université catholique de Louvain, Place L. Pasteur 1, bte L4.01.01, B-1348 Louvain-la-Neuve, Belgium
Interests: macro- and supramolecular chemistry; stimuli responsive polymers; self-assembly; polymer gels and networks, interlocked architectures; molecular machines
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Stimuli-responsive, or “smart”, polymeric systems have drawn increasing interest over the last years due to their considerable potential for widely varied applications. (Co)polymers have been developed that respond to a very broad range of external stimuli, such as pH, temperature, light, redox, salt, CO₂, electric or magnetic fields, mechanical stimulation, etc. The recent progress in controlled polymerization techniques have greatly facilitated the synthesis of well-defined polymers with tailored functionality. Among those, polymers bearing different types of responsive groups, the so-called multi-responsive polymers, have been developed. These systems exhibit complex responsive behaviors and are particularly promising.

This Special Issue of Polymers entitled “Stimuli-Responsive Polymers” will cover a broad range of research activities, such as synthesis, physico-chemical properties, and applications, as well as a broad range of polymeric systems such as solutions, films, brushes, self-assembling systems, gels, supramolecular polymers, etc. In addition, review papers featuring progresses in a particular area are welcomed. This Special Issue aims at collecting recent findings and comprehensive reviews from experts in this very active field of research, and will be hopefully a useful source of information for researchers.

Prof. Charles-André Fustin
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Thermo-responsive
Light-responsive
Mechano-responive
Redox-responsive
pH-responsive
Field-responsive
Synthesis
Physical properties
Solution
Gel and network
Film
Self-assembly
Brush
Supramolecular polymers

Related Special Issue

Stimuli Responsive Polymers II in Polymers (8 articles)

Published Papers (13 papers)

Download All Papers

Research

Jump to: Review

16 pages, 466 KiB

Open AccessArticle

Coarse-Grained Simulations of Aqueous Thermoresponsive Polyethers

by Bryan Raubenolt, Gaurav Gyawali, Wenwen Tang, Katy S. Wong and Steven W. Rick

Polymers 2018, 10(5), 475; https://doi.org/10.3390/polym10050475 - 27 Apr 2018

Cited by 12 | Viewed by 4140

Abstract

Thermoresponsive polymers can change structure or solubility as a function of temperature. Block co-polymers of polyethers have a response that depends on polymer molecular weight and co-polymer composition. A coarse-grained model for aqueous polyethers is developed and applied to polyethylene oxide and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock co-polymers. In this model, no interaction sites on hydrogen atoms are included, no Coulombic interactions are present, and all interactions are short-ranged, treated with a combination of two- and three-body terms. Our simulations find that The triblock co-polymers tend to associate at temperatures above 350 K. The aggregation is stabilized by contact between The hydrophobic methyl groups on The propylene oxide monomers and involves a large, favorable change in entropy. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

23 pages, 4141 KiB

Open AccessArticle

The Role of Chain Molecular Weight and Hofmeister Series Ions in Thermal Aggregation of Poly(2-Isopropyl-2-Oxazoline) Grafted Nanoparticles

by Martina Schroffenegger, Ronald Zirbs, Steffen Kurzhals and Erik Reimhult

Polymers 2018, 10(4), 451; https://doi.org/10.3390/polym10040451 - 17 Apr 2018

Cited by 18 | Viewed by 4795

Abstract

Thermoresponsive nanoparticles are promising smart materials for many applications. However, a rational design for applications requires a deeper understanding and experimental verification of the various parameters that influence the thermoresponsiveness of the spherical polymer brushes that define most of such nanomaterials. Therefore, we investigate superparamagnetic iron oxide nanoparticles (SPION) grafted with poly(2-isopropyl-2-oxazoline) (6–33 kg mol⁻¹) by temperature-cycled dynamic light scattering and differential scanning calorimetry. The grafting of dense spherical polymer brushes leads to lower aggregation temperatures and transition enthalpies when compared with the free polymer. The transition enthalpy and temperature depend on the polymer shell size and structure. The addition of kosmotropic salts decreases the aggregation temperature following the Hofmeister series. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

22 pages, 3229 KiB

Open AccessArticle

Exploring Poly(ethylene glycol)-Polyzwitterion Diblock Copolymers as Biocompatible Smart Macrosurfactants Featuring UCST-Phase Behavior in Normal Saline Solution

by Noverra M. Nizardo, Dirk Schanzenbach, Eric Schönemann and André Laschewsky

Polymers 2018, 10(3), 325; https://doi.org/10.3390/polym10030325 - 15 Mar 2018

Cited by 28 | Viewed by 7676

Abstract

Nonionic-zwitterionic diblock copolymers are designed to feature a coil-to-globule collapse transition with an upper critical solution temperature (UCST) in aqueous media, including physiological saline solution. The block copolymers that combine presumably highly biocompatible blocks are synthesized by chain extension of a poly(ethylene glycol) (PEG) macroinitiator via atom transfer radical polymerization (ATRP) of sulfobetaine and sulfabetaine methacrylates. Their thermoresponsive behavior is studied by variable temperature turbidimetry and ¹H NMR spectroscopy. While the polymers with polysulfobetaine blocks exhibit phase transitions in the physiologically interesting window of 30–50 °C only in pure aqueous solution, the polymers bearing polysulfabetaine blocks enabled phase transitions only in physiological saline solution. By copolymerizing a pair of structurally closely related sulfo- and sulfabetaine monomers, thermoresponsive behavior can be implemented in aqueous solutions of both low and high salinity. Surprisingly, the presence of the PEG blocks can affect the UCST-transitions of the polyzwitterions notably. In specific cases, this results in “schizophrenic” thermoresponsive behavior displaying simultaneously an UCST and an LCST (lower critical solution temperature) transition. Exploratory experiments on the UCST-transition triggered the encapsulation and release of various solvatochromic fluorescent dyes as model “cargos” failed, apparently due to the poor affinity even of charged organic compounds to the collapsed state of the polyzwitterions. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

12 pages, 8427 KiB

Open AccessArticle

Ultrasound- and Thermo-Responsive Ionic Liquid Polymers

by Kohei Itsuki, Yuuki Kawata, Komol Kanta Sharker and Shin-ichi Yusa

Polymers 2018, 10(3), 301; https://doi.org/10.3390/polym10030301 - 11 Mar 2018

Cited by 6 | Viewed by 4461

Abstract

Poly(sodium 2-acrylamido-2-methylpropanesulfonate) (PAMPSNa) was prepared via reversible addition-fragmentation chain transfer (RAFT) radical polymerization. An ionic liquid polymer (PAMPSP₄₄₄₈) was then prepared by exchanging the pendant counter cation from sodium (Na⁺) to tributyl-n-octylphosphonium (P₄₄₄₈⁺). We studied the ultrasound- and thermo-responsive behaviors of PAMPSP₄₄₄₈ in water. When the aqueous PAMPSP₄₄₄₈ solution was heated from 5 to 50 °C, the solution was always transparent with 100% transmittance. Unimers and interpolymer aggregates coexisted in water in the temperature range 5–50 °C. Generally, hydrogen bonding interactions are broken as the temperature increases due to increased molecular motion. Above 25 °C, the size of the interpolymer aggregates decreased, because hydrophobic interactions inside them were strengthened by dehydration accompanying cleavage of hydrogen bonds between water molecules and the pendant amide or sulfonate groups in PAMPSP₄₄₄₈. Above 25 °C, sonication of the aqueous solution induced an increase in the collision frequency of the aggregates. This promoted hydrophobic interactions between the aggregates to form larger aggregates, and the aqueous solution became turbid. When the temperature was decreased below 8 °C, hydrogen bonds reformed between water molecules and the pendant amide or sulfonate groups, allowing PAMPSP₄₄₄₈ to redissolve in water to form a transparent solution. The solution could be repeatedly controlled between turbidity and transparency by sonication and cooling, respectively. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

18 pages, 6940 KiB

Open AccessArticle

Novel Amphiphilic, Biodegradable, Biocompatible, Thermo-Responsive ABA Triblock Copolymers Based on PCL and PEG Analogues via a Combination of ROP and RAFT: Synthesis, Characterization, and Sustained Drug Release from Self-Assembled Micelles

by Wenyan Ning, Pei Shang, Jie Wu, Xiaoyu Shi and Shouxin Liu

Polymers 2018, 10(2), 214; https://doi.org/10.3390/polym10020214 - 22 Feb 2018

Cited by 26 | Viewed by 7576

Abstract

Well-defined novel, linear, biodegradable, amphiphilic thermo-responsive ABA-type triblock copolymers, poly[2-(2-methoxyethoxy) ethyl methacrylate-co-oligo(ethylene glycol) methacrylate]-b-poly(ε-caprolactone)-b-poly[2-(2-methoxyethoxy) ethyl methacrylate-co-oligo(ethylene glycol) methacrylate] [P(MEO₂MA-co-OEGMA)-b-PCL-b-P(MEO₂MA-co-OEGMA)] (tBPs), were synthesized via a combination of ring-opening polymerization (ROP) of ε-caprolactone (εCL) and reversible addition-fragmentation chain transfer polymerization (RAFT) of MEO₂MA and OEGMA comonomers. The chemical structures and compositions of these copolymers were characterized using Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (¹H NMR). The molecular weights of the copolymers were obtained using gel permeation chromatography (GPC) measurements. Thermo-responsive micelles were obtained by self-assembly of copolymers in aqueous medium. The temperature sensitivity and micelllization behavior of amphiphilic triblock copolymers solutions were studied by transmittance, fluorescence probe, surface tension, dynamic light scattering (DLS) and transmission electron microscopy (TEM). A hydrophobic drug, anethole, was encapsulated in micelles by using the dialysis method. The average particle sizes of drug-loaded micelles were determined by dynamic light scattering measurement. In vitro, the sustained release of the anethole was performed in pH 7.4 phosphate-buffered saline (PBS) at different temperatures. Results showed that the triblock copolymer’s micelles were quite effective in the encapsulation and controlled release of anethole. The vial inversion test demonstrated that the triblock copolymers could trigger the sol-gel transition which also depended on the temperature, and its sol-gel transition temperature gradually decreased with increasing concentration. The hydrogel system could also be used as a carrier of hydrophobic drugs in medicine. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

13 pages, 5038 KiB

Open AccessArticle

Surface-Engineered Nanocontainers Based on Molecular Self-Assembly and Their Release of Methenamine

by Minghui Zhang, Jinben Wang, Pei Zhang and Haike Yan

Polymers 2018, 10(2), 163; https://doi.org/10.3390/polym10020163 - 08 Feb 2018

Cited by 2 | Viewed by 3565

Abstract

The mixing of polymers and nanoparticles is opening pathways for engineering flexible composites that exhibit advantageous functional properties. To fabricate controllable assembling nanocomposites for efficiently encapsulating methenamine and releasing them on demand, we functionalized the surface of natural halloysite nanotubes (HNTs) selectively with polymerizable gemini surfactant which has peculiar aggregation behavior, aiming at endowing the nanomaterials with self-assembly and stimulative responsiveness characteristics. The micromorphology, grafted components and functional groups were identified using transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The created nanocomposites presented various characteristics of methenamine release with differences in the surface composition. It is particularly worth mentioning that the controlled release was more efficient with the increase of geminized monomer proportion, which is reasonably attributed to the fact that the amphiphilic geminized moieties with positive charge and obvious hydrophobic interactions interact with the outer and inner surface in different ways through fabricating polymeric shell as release stoppers at nanotube ends and forming polymer brush into the nanotube lumen for guest immobilization. Meanwhile, the nanocomposites present temperature and salinity responsive characteristics for the release of methenamine. The combination of HNTs with conjugated functional polymers will open pathways for engineering flexible composites which are promising for application in controlled release fields. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

13 pages, 1960 KiB

Open AccessArticle

Temperature-Responsive Polymer Microgel-Gold Nanorods Composite Particles: Physicochemical Characterization and Cytocompatibility

by Aslam Khan, Tajdar Husain Khan, Maqusood Ahamed, Ahmed Mohamed El-Toni, Ali Aldalbahi, Javed Alam and Tansir Ahamad

Polymers 2018, 10(1), 99; https://doi.org/10.3390/polym10010099 - 20 Jan 2018

Cited by 12 | Viewed by 6391

Abstract

In this paper, we report an easy route for preparing new metal nanorod-polymer composites consisting of gold nanorods, Au NRs, and temperature responsive copolymer “microgel” particles. The microgel particles of ~200 nm in size, which contain carboxylic acid groups, were prepared by surfactant-free emulsion polymerization of a selected mixture made of N-isopropylacylamide and acrylic acid in the presence of a cross-linker N,N′-methylenebisacrylamide. The electrostatic interactions between the cationic cetyltrimethylammonium bromide (CTAB) stabilized Au NRs and anionic microgel particles were expected to occur in order to prepare stable Au NRs-microgel composite particles. The optical and structural characterization of the composite was achieved using UV-Vis spectroscopy, Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM) and dynamic light scattering (DLS). TEM image shows that Au NRs are attached on the surface of the microgel particles. Dynamic light scattering measurements prove that the composite particles are temperature responsive, which means the particles undergo a decrease in size as the temperature increases above its phase transition temperature. In vitro cytotoxicity of the composite materials were tested by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Lactate dehydrogenase (LDH), and hemolysis assay, which showed non-toxicity (biocompatibility). Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

15 pages, 3763 KiB

Open AccessArticle

Bleomycin-Loaded pH-Sensitive Polymer–Lipid-Incorporated Liposomes for Cancer Chemotherapy

by Eiji Yuba, Tomohiro Osaki, Misato Ono, Shinjae Park, Atsushi Harada, Masamichi Yamashita, Kazuo Azuma, Takeshi Tsuka, Norihiko Ito, Tomohiro Imagawa and Yoshiharu Okamoto

Polymers 2018, 10(1), 74; https://doi.org/10.3390/polym10010074 - 15 Jan 2018

Cited by 32 | Viewed by 7234

Abstract

Cancer chemotherapeutic systems with high antitumor effects and less adverse effects are eagerly desired. Here, a pH-sensitive delivery system for bleomycin (BLM) was developed using egg yolk phosphatidylcholine liposomes modified with poly(ethylene glycol)-lipid (PEG-PE) for long circulation in the bloodstream and 2-carboxycyclohexane-1-carboxylated polyglycidol-having distearoyl phosphatidylethanolamine (CHexPG-PE) for pH sensitization. The PEG-PE/CHexPG-PE-introduced liposomes showed content release responding to pH decrease and were taken up by tumor cells at a rate 2.5 times higher than that of liposomes without CHexPG-PE. BLM-loaded PEG-PE/CHexPG-PE-introduced liposomes exhibited comparable cytotoxicity with that of the free drug. Intravenous administration of these liposomes suppressed tumor growth more effectively in tumor-bearing mice than did the free drug and liposomes without CHexPG-PE. However, at a high dosage of BLM, these liposomes showed severe toxicity to the spleen, liver, and lungs, indicating the trapping of liposomes by mononuclear phagocyte systems, probably because of recognition of the carboxylates on the liposomes. An increase in PEG molecular weight on the liposome surface significantly decreased toxicity to the liver and spleen, although toxicity to the lungs remained. Further improvements such as the optimization of PEG density and lipid composition and the introduction of targeting ligands to the liposomes are required to increase therapeutic effects and to reduce adverse effects. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

7 pages, 2548 KiB

Open AccessArticle

Gold Nanospheres Dispersed Light Responsive Epoxy Vitrimers

by Zhenhua Wang, Zhen Li, Yen Wei and Yan Ji

Polymers 2018, 10(1), 65; https://doi.org/10.3390/polym10010065 - 11 Jan 2018

Cited by 24 | Viewed by 5013

Abstract

Vitrimers represent a new class of smart materials. They are covalently crosslinked like thermosets, yet they can be reprocessed like thermoplastics. The underlying mechanism is the rapid exchange reactions which form new bonds while breaking the old ones. So far, heating is the most widely used stimulus to activate the exchange reaction. Compared to heating, light not only is much more convenient to achieve remote and regional control, but can also offer fast healing. Gold nanospheres are excellent photothermal agents, but they are difficult to disperse into vitrimers as they easily aggregate. In this paper, we use polydopamine to prepare gold nanospheres. The resultant polydopamine-coated gold nanospheres (GNS) can be well dispersed into epoxy vitrimers, endowing epoxy vitrimers with light responsivity. The composites can be reshaped permanently and temporarily with light at different intensity. Efficient surface patterning and healing are also demonstrated. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

3482 KiB

Open AccessArticle

Preparation of a Mini-Library of Thermo-Responsive Star (NVCL/NVP-VAc) Polymers with Tailored Properties Using a Hexafunctional Xanthate RAFT Agent

by Norma Aidé Cortez-Lemus and Angel Licea-Claverie

Polymers 2018, 10(1), 20; https://doi.org/10.3390/polym10010020 - 24 Dec 2017

Cited by 17 | Viewed by 6380

Abstract

A mini-library of star-shaped thermoresponsive polymers having six arms was prepared using a hexafunctional xanthate by reversible addition–fragmentation chain transfer (RAFT) polymerization. Star polymers with homopolymeric arms of poly(N-vinylcaprolactam) (PNVCL), copolymeric arms of poly(N-vinylcaprolactam-co-N-vinylpyrrolidone) (PNVCL-co-PNVP) and also arms of block copolymers of PNVCL-b-PVAc, (PNVCL-co-PNVP)-b-PVAc, and combinations of them changing the order of the block was achieved exploiting the R-RAFT synthetic methodology (or R-group approach), wherein the thiocarbonyl group is transferred to the polymeric chain end. Taking advantage of the RAFT benefits, the molecular weight of the star polymers was controlled (M_n = 11,880–153,400 g/mol) to yield star polymers of different sizes and lower critical solution temperature (LCST) values. Removing the xanthate group of the star polymers allowed for the introduction of specific functional groups at the ends of the star arms and resulted in an increase of the LCST values. Star PNVCL-b-PVAc diblock copolymers with PVAc contents of 5–26 mol % were prepared; the hydrophobic segment (PVAc) is located at the end of the star arms. Interestingly, when the PVAc content was 5–7 mol %, the hydrodynamic diameter (D_h) value of the aggregates formed in water was almost the same sa the D_h of the corresponding PNVCL star homopolymers. It is proposed that these star block copolymers self-assemble into single flowerlike micelles, showing great stability in aqueous solution. Star block copolymers with the PVAc hydrophobic block in the core of the star, such as PVAc-b-(PNVCL-co-PNVP), form micellar aggregates in aqueous solution with D_h values in the range from ~115 to 245 nm while maintaining a thermoresponsive behavior. Micellar aggregates of selected star polymers were used to encapsulate methotrexate (MTX) showing their potential in the temperature controlled release of this antineoplasic drug. The importance of the order in which each block constituent is introduced in the arms of the star polymers for their solution/aggregation behavior is demonstrated. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

3740 KiB

Open AccessArticle

Design of a Versatile pH-Responsive Hydrogel for Potential Oral Delivery of Gastric-Sensitive Bioactives

by Angus R. Hibbins, Pradeep Kumar, Yahya E. Choonara, Pierre P. D. Kondiah, Thashree Marimuthu, Lisa C. Du Toit and Viness Pillay

Polymers 2017, 9(10), 474; https://doi.org/10.3390/polym9100474 - 27 Sep 2017

Cited by 40 | Viewed by 9821

Abstract

A pH-responsive hydrogel system was prepared by free radical polymerization of acrylamide and methyl acrylic acid in the presence of N-N′-methylene bisacrylamide. Sodium bicarbonate was further applied as a blowing agent, which afforded a porous hydrogel structure. The hydrogel system achieved a constant super swelling rate within simulated intestinal buffer (~4%/min) and remained relatively static within simulated gastric buffer (~0.8%/min). The hydrogel system was able to achieve matrix resilience greater than 30% under a relatively high strain of 40%. In addition, the hydrogel system demonstrated significant swelling properties in response to simulated intestinal environmental over 24 h, with contrasting characteristics in simulated gastric buffer. The hydrogel demonstrated type IV isotherm porosity characteristics, with remarkable MRI and SEM variations in gastric and intestinal simulated fluids. Drug loading was observed to be greater than 98% using theophylline as a prototype drug, evaluating its controlled release kinetics over 24 h. The hydrogel exhibited substantial pH-responsive activity, which could be used as a versatile platform for targeted release of gastric-sensitive therapeutics to the small intestine. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

Review

Jump to: Research

32 pages, 15997 KiB

Open AccessReview

Polyaniline Coated Core-Shell Typed Stimuli-Responsive Microspheres and Their Electrorheology

by Yu Zhen Dong, Wen Jiao Han and Hyoung Jin Choi

Polymers 2018, 10(3), 299; https://doi.org/10.3390/polym10030299 - 10 Mar 2018

Cited by 20 | Viewed by 8923

Abstract

Functional core-shell-structured particles have attracted considerable attention recently. This paper reviews the synthetic methods and morphologies of various electro-stimuli responsive polyaniline (PANI)-coated core-shell-type microspheres, including PANI-coated Fe₃O₄, SiO₂, Fe₂O₃, TiO₂, poly(methyl methacrylate), poly(glycidyl methacrylate), and polystyrene along with their electrorheological (ER) characteristics when prepared by dispersing these particles in an insulating medium. In addition to the various rheological characteristics and their analysis, such as shear stress and yield stress of their ER fluids, this paper summarizes some of the mechanisms proposed for ER fluids to further understand the responses of ER fluids to an externally applied electric field. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Graphical abstract

3728 KiB

Open AccessReview

Photosensitive Layer-by-Layer Assemblies Containing Azobenzene Groups: Synthesis and Biomedical Applications

by Uichi Akiba, Daichi Minaki and Jun-ichi Anzai

Polymers 2017, 9(11), 553; https://doi.org/10.3390/polym9110553 - 25 Oct 2017

Cited by 22 | Viewed by 7246

Abstract

This review provides an overview of the syntheses of photosensitive layer-by-layer (LbL) films and microcapsules modified with azobenzene derivatives and their biomedical applications. Photosensitive LbL films and microcapsules can be prepared by alternate deposition of azobenzene-bearing polymers and counter polymers on the surface of flat substrates and microparticles, respectively. Azobenzene residues in the films and microcapsules exhibit trans-to-cis photoisomerization under UV light, which causes changes in the physical or chemical properties of the LbL assemblies. Therefore, azobenzene-functionalized LbL films and microcapsules have been used for the construction of photosensitive biomedical devices. For instance, cell adhesion on the surface of a solid can be controlled by UV light irradiation by coating the surface with azobenzene-containing LbL films. In another example, the ion permeability of porous materials coated with LbL films can be regulated by UV light irradiation. Furthermore, azobenzene-containing LbL films and microcapsules have been used as carriers for drug delivery systems sensitive to light. UV light irradiation triggers permeability changes in the LbL films and/or decomposition of the microcapsules, which results in the release of encapsulated drugs and proteins. Full article

(This article belongs to the Special Issue Stimuli Responsive Polymers)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Stimuli Responsive Polymers

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Related Special Issue

Published Papers (13 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI