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Background Nanocarriers-derived antitumor therapeutics are often associated with issues of limited tumor penetration and dissatisfactory antitumor efficacies. Some multistage delivery systems have been constructed to address these issues, but they are often accompanied with complicated manufacture processes and undesirable biocompatibility, which hinder their further application in clinical practices. Herein, a novel dual-responsive multi-pocket nanoparticle was conveniently constructed through self-assembly and cross-linking of amphiphilic methoxypolyethylene glycol-lipoic acid (mPEG-LA) conjugates to enhance tumor penetration and antitumor efficacy. Results The multi-pocket nanoparticles (MPNs) had a relatively large size of ~ 170 nm at physiological pH which results in prolonged blood circulation and enhanced accumulation at the tumor site. But once extravasated into acidic tumor interstices, the increased solubility of PEG led to breakage of the supramolecular nanostructure and dissolution of MPNs to small-sized (3) bearing mice with reduced side effect. Conclusions Our facile fabrication of multi-pocket nanoparticles provided a promising way in improving solid tumor penetration and achieving a great therapeutic efficacy. Graphic Abstract

Graphene oxide (GO) is a two-dimensional atom-thick sheet generated from an oxidation of graphene. GO possesses a range of reactive oxygen functional groups on the basal planes and edges, which makes it a good candidate in the field of separation and enrichment through chemical functionalization. In this work, GO-based Fe3O4 magnetic nanoparticles were prepared, and boronic acid groups were introduced by 3-aminophenylboronic acid (APBA) at the same time to improve the enrichment efficiency. Herein, the GO-based magnetic boronate-affinity adsorbent (Fe3O4@GO@APBA) was developed focusing on the specific capture of low abundance of glycoprotein. The composites gathered excellent characters of large specific surface area and biocompatibility of GO, strong magnetic responsiveness, and enhanced affinity properties of boronic acid. The proposed system showed better specificity for glycoprotein even in the presence of non-glycoproteins. As a result, the prepared Fe3O4@GO@APBA not only exhibited high selectivity for horseradish peroxidase (HRP), and an outstanding tolerance for interference, but also showed excellent rebinding rate for an extraction application. Furthermore, this method provided a reliable way to improve conventional magnetic adsorbent, and showed great potential in analysis of low-abundant glycoprotein from even complex samples.

Interfacial solar evaporators (ISEs) for seawater desalination have garnered enormous attention in recent decades due to global water scarcity. Despite the progress in the energy conversion efficiency and production rate of ISE, the poor portability of large-area ISE during transportation as well as the clogging of water transport pathways by precipitated salts during operation remain grand challenges for its fielded applications. Here, we designed an ISE with high energy conversion efficiency and shape morphing capability by integrating carbon nanotube (CNT) fillers with a light-responsive shape memory polymer (SMP, cross-linked polycyclooctene (cPCO)). Utilizing the shape memory effect, our ISE can be folded to an origami with 1/9 of its original size to save space for transportation and allow for on-demand unfolding upon sunlight irradiation when deployed in service. In addition, the ISE is equipped with a real-time clogging monitoring function by measuring the capacitance of the electric double layer (EDL) formed at the evaporator/seawater nanointerface. Due to its good energy conversion efficiency, high portability, and clogging monitoring capability, we envisage our ISE as a promising selection in solar evaporation technologies.

The pulse is a key biomedical signal containing various human physiological and pathological information highly related to cardiovascular diseases. Pulse signals are often collected from the radial artery based on Traditional Chinese Medicine, or by using flexible pressure sensors. However, the wrist wrapped with a flexible pressure sensor exhibits unstable signals under hand motion because of the concave surface of the wrist. By contrast, fingertips have a convex surface and therefore show great promises in stable and long-term pulse monitoring. Despite the promising potential, the fingertip pulse signal is weak, calling for highly sensitive detecting devices. Here, a highly sensitive and flexible iontronic pressure sensor with a linear sensitivity of 13.5 kPa-1 , a swift response, and remarkable stability over 5000 loading/unloading cycles is developed. This sensor enables stable and high-resolution detection of pulse waveform under both static condition and finger motion. Fingertip pulse waveforms from subjects of different genders, age, and health conditions are collected and analyzed, suggesting that fingertip pulse information is highly similar to that of the radial artery. This work justifies that fingertip is an ideal platform for pulse signals monitoring, which would be a competitive alternative to existing complex health monitoring systems.

Boronate-affinity magnetic hollow molecularly imprinted polymers (B-MhMIPs) were prepared with sialic acid (SA) as the template, 3-aminophenylboronic acid (APBA) as the functional monomer and glycidilmethacrylate (GMA) as the co-monomer to chemisorb Fe3O4 nanoparticles. Furthermore, the hollow structure made the nanoparticles have more binding sites at both internal and external surfaces, which can facilitate the removal of template molecules from polymers and enhance the adsorption abilities towards SA. After optimizing, the adsorption pH was controlled at 4.0, and this was different from most cis-diol-containing compounds. Under the optimal conditions, the limit of detection for SA was 0.025 μg mL−1 (n = 3). This method was applied to analyze serum samples with different spiked levels, and the recoveries of the SA were in the range of 70.9–106.2%. These results confirmed the superiority of the B-MhMIPs for selective and efficient enrichment of trace SA from complex matrices.

In this study, a new boronate-affinity hollow adsorbent was successfully fabricated. This adsorbent was prepared using mesoporous MCM-48 as a sacrificial support, methacrylic acid (MAA), N,N-methylenebisacrylamide (MBA) and azobisisobutyronitrile (AIBN) were applied as a functional monomer, cross-linker and initiator, respectively, and further modified with boronic acid groups (4-vinylphenylboronic acid, VPBA) to improve the enrichment efficiency. Such materials were composed of a hollow structure, a hydrophilic polymer coating of poly(MBA-MAA), and a VPBA-functionalized shell designed for capturing isoflavones. The resulting material coupled with high-performance liquid chromatography (HPLC) was applied to analyze three cis-diol isoflavones (daidzin, glycitin, and genistin) in soybean milk samples. The sorbent was characterized by transmission electron microscopy, Fourier transform infrared spectrometry and thermo-gravimetric analysis. Several parameters affecting the extraction efficiency were optimized. Owing to the hollow structure, more binding sites were located on the inner and outer surfaces of this material, which could facilitate the binding of the target molecules to the adsorbent. Adsorption selectivity studies indicated that the prepared material can selectively recognize isoflavones. Under optimized conditions, the limits of detection of the method were 3.8 to 7.3 μg L−1 for the three isoflavones based on a signal-to-noise ratio of 3 : 1. The spiked recoveries were found to be between 67.4 and 104.7% (the relative standard deviations were less than 3.8%, n = 3). This indicated the superiority of the method in selective extraction of isoflavones even from complex matrices.

The authors describe boronate-modified hollow dummy template imprinted polymers (B-hDIPs) for selective and sensitive extraction of the catecholamines norepinephrine (NE), epinephrine (E), and dopamine (DA) from urine samples prior to their detection by HPLC with UV detector. The B-hDIPs were prepared by using (a) nano-TiO2 as the sacrificial support, (b) 3-carboxyphenylboronic acid (CPBA) as the boronate-affinity functional monomer, and (c) catechol which acts as dummy template. The nano-TiO2 can be etched off by using hydrofluoric acid to form the hollow imprint. The main advantages of using such hollow polymers arise from their controllable hole structure which favors template removal and fast mass transfer. The B-hDIPs material was characterized by FT-IR, transmission electron microscope, dynamic light scattering, X-ray photoelectron spectrum, and thermal gravimetric analysis. The effects of imprinting conditions, sample pH, sample flow rate, adsorbent amount, selectivity and competitive capacities were investigated. Under optimal conditions, the limits of detection for the catecholamines are in the range from 15 to 47 ng mL−1. The method was successfully applied to their determination of NE, E, and DA in spiked urine, with recoveries ranging from 63.4 to 106.2%.

Hollow structured l -lysine modified polydopamine coating shells (h-PDA@L-lys) were prepared using polystyrene (PS) as sacrificial support, the dopamine was used to coat PS by self-polymerization, L-lys as adsorpt ligand. The PS can be etched to form hollow structure, where more binding sites locate on the inner and outer surfaces can be utilized maximum. The h-PDA@L-lys were used as adsorbent for the specific bilirubin (BR) enrichment from animal livers. The adsorbent was characterized in details and its selectivity and binding capacity were evaluated. The experimental conditions (sample pH, adsorbent amounts, eluent types, eluent pH and volume) were optimized. The results indicate that h-PDA@L-lys exhibite good selective adsorption ability and higher adsorption amount. According to the adsorption experiments, the adsorption kinetics obey pseudo-second-order adsorption kinetics and the equilibrium data are best described by Langmuir isotherm model. The saturated adsorption capacity is 12.0 mg g−1, which is not only higher than the adsorption capacities of non-hollow adsorbents, but also superior to those of many reported adsorbents for enrich of BR. Moreover, this method was successfully applied in the selective recognition of BR in animal livers. Thus, this work provide potential possibility and practical platform for detection of BR in complex matrices.

D-Glucose was used as a dummy template in a strategy to fabricate boronate-based hollow molecularly imprinted polymers (h-MIPs) for the recognition of glycosides. 3-Aminophenylboronic acid (APBA) was selected as the functional monomer to impart glycoside binding capability. A polystyrene core was synthesized via an emulsifier-free emulsion polymerization. It was then be corroded to form a hollow structure where the binding sites on the inner surface can be fully utilized. Adsorption studies indicate that the resulting h-MIPs can specifically recognize glycosides. The h-MIPs were applied as a sorbent for solid phase extraction of the glycosides (daidzin, glycitin, rutin, and genistin) in soy products. Following desorption with 1% TFA in acetonitrile-water (3:7, v/v), the glycosides were quantified by HPLC with UV detection. The detection limits for the glycosides range from 3.5 to 10.8 ng·mL−1.

In this work, the boronate-affinity hollow stannic oxide based fragment template molecularly imprinted polymers (Bh@SnO2-FMIPs) were fabricated successfully. Polystyrene was used as sacrificial support, SnO2 was selected as inorganic matrix, surface imprinting using catechol as fragment template and 4-vinylphenylboronic acid as boronate-affinity functional monomer. A thin layer of poly 2-anilinoethanol (2-AE) was formed to coat the boronate-affinity hollow SnO2 surface through self-polymerization, it has strong hydrophilicity and limited residual boric acid content, avoiding non-specific binding. The hollow structure could bind to target molecules effectively and facilitate the removal of template molecules. The Bh@SnO2-FMIPs were used to extract three cis-diol polyphenols containing catechin, chlorogenic acid, and caffeic acid in tea and juice samples. Combination with seven characterizations of the material confirmed the successful preparation. Effecting the imprinting conditions and extraction efficiency parameters were optimized separately. Selective and competitive adsorption experiments indicated that the materials could specific recognition polyphenols. Using solid phase extraction and high performance liquid chromatography method, the detection limits were 0.005–0.046 μg mL−1 and the recoveries were between 82.3–104.3%. The improved adsorption performance may be assigned to the synergistic effects among boronate-affinity, hollow SnO2, and 2-AE self-polymerization. It may enhance binding cavities, hydrophilicity, biocompatibility of adsorbent material, and prevent the aggregation of Sn during the preparation processes.