Piezoelectric and triboelectric nanogenerators have been developed as rising energy-harvesting devices in the past few years to effectively convert mechanical energy into electricity. Here, a novel ...hybrid piezo/triboelectric nanogenerator based on BaTiO3 NP/PDMS composite film was developed in a simple and low-cost way. The effects of the BTO content and polarization degree on the output performance were systematically studied. The device with 20 wt % BTO in PDMS and a 100-μm-thick film showed the highest output power. We also designed three measurement modes to record hybrid, triboelectric, and piezoelectric outputs separately with a simple structure that has only two electrodes. The hybrid output performance is higher than the tribo- and piezoelectric performances. This work will provide not only a new way to enhance the output power of nanogenerators, but also new opportunities for developing built-in power sources in self-powered electronics.
Insufficient tumor accumulation and distribution of photosensitizers as well as low antitumor immunity severely restrict the therapeutic efficacy of photothermal therapy (PTT). Cancer-associated ...fibroblasts (CAFs) play a key role in tumor extracellular matrix (ECM) remodeling and immune evasion. Reshaping tumor microenvironment via CAF regulation might provide a potential approach for complete tumor elimination in combination with PTT. Here, tumor cell-derived microparticles co-delivering calcipotriol and Indocyanine green (Cal/ICG@MPs) are developed to modulate CAFs for improved PTT efficacy. Cal/ICG@MPs efficiently target tumor tissues and regulate CAFs to reduce tumor ECM, resulting in enhanced tumor accumulation and penetration of ICG to generate strong PTT efficacy and activate CD8
T cell-mediated antitumor immunity. In addition, Cal/ICG@MPs-triggered CAF regulation enhances tumor infiltration of CD8
T cells and ameliorates CAF-induced antigen-mediated activation-induced cell death of tumor-specific CD8
T cells in response to PTT, eliciting long-term antitumor immune memory to inhibit tumor recurrence and metastasis. Our results support Cal/ICG@MPs as a promising drug to improve PTT efficacy in cancer treatment.
The main challenges for programmed cell death 1(PD-1)/PD-1 ligand (PD-L1) checkpoint blockade lie in a lack of sufficient T cell infiltration, tumor immunosuppressive microenvironment, and the ...inadequate tumor accumulation and penetration of anti-PD-1/PD-L1 antibody. Resetting tumor-associated macrophages (TAMs) is a promising strategy to enhance T-cell antitumor immunity and ameliorate tumor immunosuppression. Here, mannose-modified macrophage-derived microparticles (Man-MPs) loading metformin (Met@Man-MPs) are developed to efficiently target to M2-like TAMs to repolarize into M1-like phenotype. Met@Man-MPs-reset TAMs remodel the tumor immune microenvironment by increasing the recruitment of CD8
T cells into tumor tissues and decreasing immunosuppressive infiltration of myeloid-derived suppressor cells and regulatory T cells. More importantly, the collagen-degrading capacity of Man-MPs contributes to the infiltration of CD8
T cells into tumor interiors and enhances tumor accumulation and penetration of anti-PD-1 antibody. These unique features of Met@Man-MPs contribute to boost anti-PD-1 antibody therapy, improving anticancer efficacy and long-term memory immunity after combination treatment. Our results support Met@Man-MPs as a potential drug to improve tumor resistance to anti-PD-1 therapy.
Abstract
Cyclobutanols are privileged cyclic skeletons in natural products and synthetic building blocks. C(sp3)−H functionalization is a prolonged challenge in organic synthesis. The synthesis of ...cyclobutanols through double C(sp3)-H bond functionalization remains elusive. Here we report the efficient synthesis of cyclobutanols through intermolecular radical 3 + 1 cascade cyclization, involving the functionalization of two C − H bonds through sequential hydrogen atom transfer. The copper complex reduces the iodomethylsilyl alcohols efficiently under blue-light irradiation to initiate the tandem transformation. The mild reaction tolerates a broad range of functional groups and allows for the facile generation of elaborate polycyclic structures.
Highlights
The common performance optimization strategies of smart composite hydrogel are summarized.
The recent advanced progress of smart composite hydrogel-based wearable sensors is systematically ...discussed from the aspect of health monitoring.
The current challenges and future prospects of smart composite hydrogel-based wearable sensors are presented.
Growing health awareness triggers the public’s concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome general check-ups. The wearable technique provides a continuous measurement method for health monitoring by tracking a person’s physiological data and analyzing it locally or remotely. During the health monitoring process, different kinds of sensors convert physiological signals into electrical or optical signals that can be recorded and transmitted, consequently playing a crucial role in wearable techniques. Wearable application scenarios usually require sensors to possess excellent flexibility and stretchability. Thus, designing flexible and stretchable sensors with reliable performance is the key to wearable technology. Smart composite hydrogels, which have tunable electrical properties, mechanical properties, biocompatibility, and multi-stimulus sensitivity, are one of the best sensitive materials for wearable health monitoring. This review summarizes the common synthetic and performance optimization strategies of smart composite hydrogels and focuses on the current application of smart composite hydrogels in the field of wearable health monitoring.
Herein, we synthesized a kind of magnetic covalent organic framework nanohybrids (NiFe2O4@COF), and integrated it with polydimethyl siloxane and silicone rubber curing agent for solid phase ...microextraction (SPME) fiber coating. The fiber coating demonstrated a porous and uniform surface with the BET specific surface of 169.7 m2 g-1. As for seven environmental analytes, the NiFe2O4@COF-based SPME fiber coating gave the higher extraction recoveries for triclosan (TCS) and methyltriclosn (MTCS) than those of fenpropathrin, bifenthrin, permethrin, fenvalerate and deltamethrin. Several operational parameters were rigorously optimized, such as extraction temperature, extraction time, thermal desorption time, solution pH and salt effect. Combined with the GC-ECD detection, the newly developed microextraction method supplied the wide linear range of 0.1–1000 µg L-1 with the correlation coefficients of > 0.9995. The limits of detection (LODs) and limits of quantitation (LOQs) reached as low as 1–7 ng L-1 and 3.3–23 ng L-1, respectively. The intra-day and inter-day precisions in six replicates (n = 6 ) were < 3.55% and < 5.06%, respectively, and the fiber-to-fiber reproducibility (n = 3) was < 7.64%. To evaluate its feasibility in real samples, the fortified recoveries for TCS and MTCS, at low (0.2 µg L-1), middle (2.0 µg L-1) and high (20.0 µg L-1) levels, varied between 81.9% and 119.1% in tap, river and barreled waters as well as male, female and children urine samples. Especially, it is worth mentioning that the NiFe2O4@COF-based SPME coating fiber can be recycled for at least 150 times with nearly unchanged extraction efficiency. Moreover, the extraction recoveries by the as-fabricated fiber coating were much higher than those by three commercial fibers (PDMS, PDMS/DVB and PDMS/DVB/CAR). Overall, the NiFe2O4@COF-based SPME is a convenient, sensitive, efficient and “green” pretreatment method, thereby possessing important application prospects in trace monitoring of TCS-like pollutants in complex liquid matrices.
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•A novel magnetic NiFe2O4@COF-based fiber coating for SPME is successfully fabricated.•NiFe2O4@COF nanohybrid possesses larger surface area and pore size over single COFs.•NiFe2O4@COF based SPME fiber coating provides high extraction selectivity for TCS and MTCS.•Sampling, enrichment, purification and injection are integrated into one solvent-free step.•NiFe2O4@COF-SPME/GC-ECD approach offers low LODs and high repeatability for analytes.
A method for remote radical C-H alkynylation and amination of diverse aliphatic alcohols has been developed. The reaction features a copper nucleophile complex formed
in situ
as a photocatalyst, ...which reduces the silicon-tethered aliphatic iodide to an alkyl radical to initiate 1,
n
-hydrogen atom transfer. Unactivated secondary and tertiary C-H bonds at β, γ, and δ positions can be functionalized in a predictable manner.
Remote C−H alkynylation and amination of aliphatic alcohols.
Highlights
A systematic summary of the research progress of hydrogel-based gas and humidity sensors is presented.
The sensing mechanism of hydrogel-based gas and humidity sensors is elaborated.
The ...potential of hydrogel-based vapor sensors in different fields of application is demonstrated.
Breathing is an inherent human activity; however, the composition of the air we inhale and gas exhale remains unknown to us. To address this, wearable vapor sensors can help people monitor air composition in real time to avoid underlying risks, and for the early detection and treatment of diseases for home healthcare. Hydrogels with three-dimensional polymer networks and large amounts of water molecules are naturally flexible and stretchable. Functionalized hydrogels are intrinsically conductive, self-healing, self-adhesive, biocompatible, and room-temperature sensitive. Compared with traditional rigid vapor sensors, hydrogel-based gas and humidity sensors can directly fit human skin or clothing, and are more suitable for real-time monitoring of personal health and safety. In this review, current studies on hydrogel-based vapor sensors are investigated. The required properties and optimization methods of wearable hydrogel-based sensors are introduced. Subsequently, existing reports on the response mechanisms of hydrogel-based gas and humidity sensors are summarized. Related works on hydrogel-based vapor sensors for their application in personal health and safety monitoring are presented. Moreover, the potential of hydrogels in the field of vapor sensing is elucidated. Finally, the current research status, challenges, and future trends of hydrogel gas/humidity sensing are discussed.
Highlights
A general strategy of fabricating thickness-controllable hydrogel films with diverse polymer networks for humidity sensing is proposed. The hydrogel film humidity sensor displays an ...unprecedented sensitivity up to 13,462.1%/%RH.
The stretchable humidity sensor can work normally under large tensile strains with even enhanced sensitivity, which makes the humidity responding property of hydrogel mechanically programmable.
A wireless respiratory interruption detection mask with Bluetooth transmission function is developed based on the sensor, enabling the real-time, wireless and accurate acquisition of user's breathing state, such as the interval and breathing frequency and apnea.
Respiratory monitoring plays a pivotal role in health assessment and provides an important application prospect for flexible humidity sensors. However, traditional humidity sensors suffer from a trade-off between deformability, sensitivity, and transparency, and thus the development of high-performance, stretchable, and low-cost humidity sensors is urgently needed as wearable electronics. Here, ultrasensitive, highly deformable, and transparent humidity sensors are fabricated based on cost-effective polyacrylamide-based double network hydrogels. Concomitantly, a general method for preparing hydrogel films with controllable thickness is proposed to boost the sensitivity of hydrogel-based sensors due to the extensively increased specific surface area, which can be applied to different polymer networks and facilitate the development of flexible integrated electronics. In addition, sustainable tapioca rich in hydrophilic polar groups is introduced for the first time as a second cross-linked network, exhibiting excellent water adsorption capacity. Through the synergistic optimization of structure and composition, the obtained hydrogel film exhibits an ultrahigh sensitivity of 13,462.1%/%RH, which is unprecedented. Moreover, the hydrogel film-based sensor exhibits excellent repeatability and the ability to work normally under stretching with even enhanced sensitivity. As a proof of concept, we integrate the stretchable sensor with a specially designed wireless circuit and mask to fabricate a wireless respiratory interruption detection system with Bluetooth transmission, enabling real-time monitoring of human health status. This work provides a general strategy to construct high-performance, stretchable, and miniaturized hydrogel-based sensors as next-generation wearable devices for real-time monitoring of various physiological signals.
Abstract
The durable response rate to immune checkpoint blockade such as anti-programmed cell death-1 (PD-1) antibody remains relatively low in hepatocellular carcinoma (HCC), mainly depending on an ...immunosuppressive microenvironment with limited number of CD8
+
T cells, especially stem-like CD8
+
T cells, in tumor tissues. Here we develop engineered microparticles (MPs) derived from alpha-fetoprotein (AFP)-overexpressing macrophages to load resiquimod (R848@M2pep-MPs
AFP
) for enhanced anti-PD-1 therapy in HCC. R848@M2pep-MPs
AFP
target and reprogram immunosuppressive M2-like tumor-associated macrophages (TAMs) into M1-like phenotype. Meanwhile, R848@M2pep-MPs
AFP
-reprogrammed TAMs act as antigen-presenting cells, not only presenting AFP antigen to activate CD8
+
T cell-mediated antitumor immunity, but also providing an intra-tumoral niche to maintain and differentiate stem-like CD8
+
T cells. Combination immunotherapy with anti-PD-1 antibody generates strong antitumor immune memory and induces abundant stem-like CD8
+
T cell proliferation and differentiation to terminally exhausted CD8
+
T cells for long-term immune surveillance in orthotopic and autochthonous HCC preclinical models in male mice. We also show that the R848-loaded engineered MPs derived from macrophages overexpressing a model antigen ovalbumin (OVA) can improve anti-PD-1 therapy in melanoma B16-OVA tumor-bearing mice. Our work presents a facile and generic strategy for personalized cancer immunotherapy to boost anti-PD-1 therapy.
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