Article
Biophysics
Alberto Guerron, Huu Trong Phan, Carolina Penaloza-Arias, Davide Brambilla, Valerie Gaelle Roullin, Suzanne Giasson
Summary: The attachment/detachment of cells on responsive polymer-coated surfaces is influenced by various factors including electrostatic interactions, wettability and swelling of the polymer coating. In this study, dual thermo- and pH-responsive cationic poly(N-isopropylacrylamide) microgels, surface-functionalized with PEG or PDMAEMA, were used as substrates to investigate their impact on cell behavior. The results showed that microgels with PEG chains had comparable cell adhesion and proliferation rates to controls, while exhibiting the best thermo-triggered cell detachment performance, especially for MCF7 and U138 cells. The hydrophilic nature of the microgel surface remained unchanged regardless of temperature and pH, contributing to this behavior. Swelling behavior influenced by pH resulted in significant cell detachment only for U138 cells. However, detachment of bEnd.3 cells could not be triggered by either temperature or pH, regardless of the microgel surface coating.
COLLOIDS AND SURFACES B-BIOINTERFACES
(2022)
Article
Chemistry, Analytical
Seunghyeon Nam, Hyojung Kim, Sang-Mok Lee, Mete Batuhan Durukan, Husnu Emrah Unalan, Hyunjoo J. Lee
Summary: In this study, pNIPAm microgels were used as a glucose-responsive layer to measure changes in glucose concentration based on spectral shifts. The results showed that this sensor could be used to detect sweat glucose concentration in diabetic patients, and the response time could be improved by introducing grid-shaped slits.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Materials Science, Multidisciplinary
Wenhui Cao, Qi Ding, Peng Ding, Litian Hu, Chaobin Liu, Wei Yu
Summary: The rheological properties of PNIPAM microgels and the formation mechanism of tribofilms at the sliding interface during friction were investigated. It was found that PNIPAM microgels could effectively improve the tribological performance above the critical solution temperature, by forming a gel layer that changes the friction interface and reduces the friction coefficient.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Engineering, Environmental
Jiajia Xu, Huawei Qiao, Kai Yu, Mingfeng Chen, Canpei Liu, Walter Richtering, Huagui Zhang
Summary: In this study, smart foams stabilized by Cu2+ responsive microgels were presented as a proof-of-concept and demonstrated their potential for selective recovery of Cu2+ from competitive ions. The research laid foundations for the development of microgel-based flotation as a smart and green technology for Cu2+ recovery.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Nanoscience & Nanotechnology
Kai Wang, Guoqi Chen, Sen Weng, Linxi Hou, Dezhan Ye, Xiancai Jiang
Summary: A thermo-responsive PNIPAM/HPMC hydrogel was prepared using a simple one-step low-temperature polymerization method, achieving high transmittance, high solar modulation, low phase-transition temperature, and excellent high-temperature thermal stability simultaneously. The hydrogel exhibited high light transmittance (90.82%) and good mechanical properties and thermal stability. It also showed a low phase-transition temperature (about 32 degrees C) and high solar modulation (81.52%), making it an ideal material for thermochromic smart windows.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Polymer Science
Anna Harsanyi, Attila Kardos, Imre Varga
Summary: This study investigated the possibility of post-polymerization modification of P(NIPAm-co-acrylic acid) microgels to prepare primary amine functionalized microgels. By controlling the excess of EDC in the reaction mixture, the amine content in the microgels could be varied and up to 6-7 mol% amine could be incorporated. Importantly, the reaction was conducted at room temperature in an aqueous medium, making it a practical and convenient approach.
Article
Polymer Science
Migle Babelyte, Laura Peciulyte, Vesta Navikaite-Snipaitiene, Joana Bendoraitiene, Volodymyr Samaryk, Ramune Rutkaite
Summary: Thermoresponsive chitosan-graft-poly(N-isopropylacrylamide) copolymers with different compositions were synthesized. The chemical structure of the copolymers was confirmed and their lower critical solution temperature (LCST) behavior was assessed. Copolymers with a certain content of poly(N-isopropylacrylamide) side chains demonstrated LCST behavior and could potentially be used in drug delivery systems or tissue engineering.
Article
Polymer Science
Lin Zhu, Qiusheng Song, Haihong Ma
Summary: In this study, a thermo-responsive microgel based on hyperbranched polysiloxane with aggregation induced emission (AIE) was reported for the first time. The microgel showed enhanced thermo-response and AIE-active fluorescence with increasing temperature. The drug loading and release properties of the microgel were investigated using Luteolin as a model drug. The results demonstrated that the fluorescence emission of the microgel could be adjusted by environmental temperature or the content of Luteolin, making it easy to detect the drug loading or release properties.
JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY
(2023)
Article
Polymer Science
Rui Jiang, Jiaxi Li, Zhelin Qiang, Ling Wang, Tao Wang, Shan Shi
Summary: Thermoresponsive microgels composed of PNIPAM and CS exhibit negatively thermoresponsive nature at elevated temperature, and the gelation process is influenced by polymer content and heating temperature. The behavior of thermo-induced in situ gelation was systematically studied using rheological measurements.
JOURNAL OF MACROMOLECULAR SCIENCE PART B-PHYSICS
(2021)
Review
Materials Science, Multidisciplinary
Lin Tang, Ling Wang, Xiao Yang, Yiyu Fen, Yu Li, Wei Feng
Summary: PNIPAM-based smart hydrogels are important smart materials with unique thermo-responsive properties and promising applications. This review summarizes the development, fundamental design, synthetic strategies, and potential applications of these materials in various fields.
PROGRESS IN MATERIALS SCIENCE
(2021)
Article
Polymer Science
Isala Dueramae, Taisei Ishiyama, Ayumi Torigaki, Shinya Nakano, Kaito Sasaki, Rio Kita, Naoki Shinyashiki, Shin Yagihara, Yukiteru Katsumoto, Masaru Yoneyama
Summary: The dielectric relaxation of poly-(N-isopropylacrylamide) (PNiPAM) in 1,4-dioxane as a low-polarity solvent was investigated under various conditions. The study found that the relaxation is composed of two components: rotational motion of side groups at around 100 MHz and micro-Brownian motion of PNiPAM chain at around 1 MHz. These processes can be described by two Cole-Cole equations. The relaxation times of these processes showed temperature dependence, as evidenced by the activation energies obtained from the Arrhenius plot. Additionally, asymmetric relaxation was observed in the MHz region of PNiPAM in different solvents, suggesting a deeper understanding of PNiPAM's molecular dynamics.
Article
Polymer Science
Isaac J. Gresham, Ben A. Humphreys, Joshua D. Willott, Edwin C. Johnson, Timothy J. Murdoch, Grant B. Webber, Erica J. Wanless, Andrew R. J. Nelson, Stuart W. Prescott
Summary: The structure of grafted-from poly(N-isopropylacrylamide) brushes under confinement shows a uniform internal structure and specific volume fraction distribution, eliminating the critical transition point in their thermal response. Different experimental methods find qualitative agreement, but variations exist due to path-dependent behavior.
Article
Polymer Science
Chia-Hsin Ko, Cristiane Henschel, Geethu P. Meledam, Martin A. Schroer, Peter Mueller-Buschbaum, Andre Laschewsky, Christine M. Papadakis
Summary: The temperature-dependent phase behavior and self-assembly behavior of a thermoresponsive amphiphilic diblock copolymer in aqueous solution were studied, revealing a lower critical solution temperature (LCST) behavior at 31.1 degrees Celsius and the formation of different structures of micelles.
Article
Polymer Science
Chia-Hsin Ko, Cristiane Henschel, Geethu P. Meledam, Martin A. Schroer, Renjun Guo, Luka Gaetani, Peter Mueller-Buschbaum, Andre Laschewsky, Christine M. Papadakis
Summary: The self-assembly of the thermoresponsive amphiphilic diblock copolymer PMMA(21)-b-PNIPAM(283) in various water/methanol mixtures was studied. It was found that the solvent composition significantly affected the internal morphology of micelles and the conformation of dissolved chains.
Article
Polymer Science
Fang Yin, Pascale Laborie, Barbara Lonetti, Yannick Coppel, Nancy Lauth-de Viguerie, Jean-Daniel Marty, Stephane Gineste
Summary: Doubly thermo-and pH-responsive PNIPAM-b-PDEAEAM polymers were synthesized by RAFT polymerization. The properties of these polymers and corresponding homopolymers in solution depend on pH and the protonation degree of the diethylamino moiety. The behavior of the polymers is also influenced by the nature of the polymer chain ends. At pH 10, both PNIPAM and PDEAEAM blocks contribute to phase transition and form stable spherical nanoobjects. At pH 4, PNIPAM-b-PDEAEAM with longer PDEAEAM length exhibits a two-step thermoresponsive behavior and forms large aggregates with a positively charged shell.
Article
Materials Science, Multidisciplinary
Rui Zhao, Xinyue Xu, Liang Hu
Summary: A composite hydrogel with superior mechanical properties and sensitivity was prepared for fabricating high-performance wearable sensors. The sensors showed high sensitivity to changes in strain and pressure, along with the ability to cyclically recover and self-heal.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Chemistry, Analytical
Faisal Hossain, Nicholas Balasuriya, M. Mosharraf Hossain, Michael J. Serpe
Summary: A sensor has been developed to measure the concentration of orthophosphate (PO43-) in water, which utilizes enzymatic cleavage to generate glucose. This approach demonstrates lower detection limit and wider dynamic range compared to commercial glucometers, and shows selectivity for PO43- in natural water samples. The sensor has been successfully used to determine PO43- in tap and river water samples.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Analytical
Menglian Wei, Todd Darcie, Wenwen Xu, Yongfeng Gao, Hannah Mundel, J. Stewart Aitchison, Xueji Zhang, Michael J. Serpe
Summary: The study revealed that coating the Au film of a surface plasmon resonance sensor with microgels and depositing a layer of Au on top of the microgels can enhance the sensor's sensitivity to changes in solution properties.
ANALYTICAL CHEMISTRY
(2021)
Article
Nuclear Science & Technology
Yue Yang, Cui-Ping Yang, Jie Xin, Hai-Feng Chen, Zhong-Xu Xing, Wei-Wei Qu, Liang Hu, Xin-Jian Chen, Ren-Sheng Wang
Summary: This study investigated the stability and light-dose response of photoelectric devices in a plastic scintillation fiber dosimeter (PSFD), finding that the avalanche photodiode (APD) was most sensitive to temperature. The photomultiplier tube (PMT) and silicon photomultiplier (SiPM) showed the best performance in terms of dose response and signal-to-noise ratio (SNR) within the range of 0.1-60 Gy/min. Overall, the performance of PMT and SiPM was concluded to be better than that of other devices in the study.
NUCLEAR SCIENCE AND TECHNIQUES
(2021)
Article
Engineering, Multidisciplinary
Zhang Yu, Li Chen, Yang Han, Zhao Rui, Chen XinJian, Nie BaoQing, Hu Liang
Summary: The organohydrogel-based sensor proposed in the paper is simple in design, highly sensitive, and stable, capable of responding to humidity changes in a wide range and successfully applied in detecting breathing rates and moisture differences.
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
(2022)
Article
Chemistry, Physical
Rui Zhao, Li Jiang, Ping Zhang, Dan Li, Zhenzhong Guo, Liang Hu
Summary: This study synthesized organohydrogels using graphene oxide and glycerol, showing superior mechanical properties and resistance to freezing, with rapid self-healing capabilities and good cytocompatibility. The organohydrogel-based sensor exhibited a strain gauge factor of 4.22 at 100% strain, allowing for effective monitoring of human movements.
Review
Physics, Multidisciplinary
Tong Shu, Liang Hu, Haley Hunter, Nicholas Balasuriya, Changhao Fang, Qiang Zhang, Michael J. Serpe
Summary: Micro/nanogels are unique materials that exhibit both colloidal and hydrogel properties, and can respond to various stimuli. They can be used as optical sensors to detect and transduce analyte signals into changes in optical properties.
ADVANCES IN PHYSICS-X
(2022)
Article
Materials Science, Multidisciplinary
Alyssa Fu, Michael J. Serpe
Summary: Electrochromic devices (ECDs) are ideal for electronic paper displays and have various applications. By using etalons, optical devices designed in our lab, we have successfully created color-switchable ECDs with good color retention, fast switching kinetics, and localized color changes. Moreover, etalons can act as both the electrochromic layer and one of the conducting layers, eliminating the need for an extra conducting layer. These devices show promise as low-cost, low-power, and colored display options for the future.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Chemistry, Analytical
Faisal Hossain, Qinling Shen, Nicholas Balasuriya, John Lok Man Law, Michael Logan, Michael Houghton, D. Lorne Tyrrell, Michael A. Joyce, Michael J. Serpe
Summary: A sensor was developed to quantify anti-SARS-CoV-2 spike RBD antibody levels and the SARS-CoV-2 virus in saliva and serum. The sensor utilized enzymatic reactions and magnetic microparticles to capture the analytes, followed by generating glucose in proportion to the analyte concentration using a commercial glucometer test strip. The sensor demonstrated good selectivity and accuracy, with a cost per test of around $7 for antibody quantification and $12 for virus quantification. The sensor's detection limits were sensitive enough to quantify typical concentrations of antibodies and exceeded the recommended performance for virus detection by the WHO.
ANALYTICAL CHEMISTRY
(2023)
Review
Chemistry, Analytical
Zhimin Song, Shu Zhou, Yanxia Qin, Xiangjiao Xia, Yanping Sun, Guanghong Han, Tong Shu, Liang Hu, Qiang Zhang
Summary: Flexible and wearable biosensors have attracted significant attention due to their potential applications in health and medicine. These biosensors serve as an ideal platform for real-time and continuous health monitoring, offering unique properties such as self-powered operation, lightweight design, low cost, high flexibility, and convenience in detection. This review provides an overview of recent research progress in wearable biosensors, including the detection of biological fluids, micro-nanofabrication technologies, basic characteristics, application methods, and information processing. Furthermore, it highlights cutting-edge examples such as physiological pressure sensors, sweat sensors, and self-powered biosensors, detailing their detection mechanisms for better understanding. Finally, the current challenges and future perspectives are proposed to advance this research area and expand practical applications.
Article
Materials Science, Biomaterials
Siyuan Guo, Daniel Wong, Sifan Wang, Ravleen Gill, Michael J. Serpe
Summary: Stimuli-responsive hydrogel-microgel composites (HMC) were prepared by embedding microgels in a hydrogel. The release of small molecule drugs from the HMC can be controlled by the solution temperature, material dimension, and chemical composition. The HMC can also control the release rate of multiple drugs individually in a pH-dependent manner. This research is important for designing new materials with controlled and triggered release of small molecule drugs in the biomedical field.
JOURNAL OF MATERIALS CHEMISTRY B
(2022)
Review
Polymer Science
Ping Zhang, Li Jiang, Hong Chen, Liang Hu
Summary: Ionizing radiation is widely used and has both positive and negative effects. Sensors for measuring radiation doses are crucial, especially in cancer therapy. Hydrogel-based sensors are attracting attention due to their similarity to living tissue and biocompatibility.
Article
Automation & Control Systems
Yu Wan, Keith Cuff, Michael J. Serpe
Summary: The research combines Nitinol shape memory alloy and bistable metal strips to create a swimming actuator with both slow moving and fast snapping capabilities, similar to an octopus's movement in water. The actuator is able to swim in multiple directions, controlled by a wireless module, and can potentially be used for environmental monitoring with an onboard sensor. The device has no mechanical parts, making it a cost-effective alternative to traditional boats.
ADVANCED INTELLIGENT SYSTEMS
(2022)
Review
Chemistry, Physical
Liang Hu, Tong Shu, Yu Wan, Changhao Fang, Feng Gao, Michael J. Serpe
Summary: This review discusses the responsiveness of stimuli-responsive polymers (SRPs) to external stimuli and their applications in sensing and actuation. The study includes sensors that can respond to physiologically relevant stimuli, as well as examples of SRPs used in artificial muscles, soft robots, cell culture, and drug delivery.
MOLECULAR SYSTEMS DESIGN & ENGINEERING
(2021)
