•A novel copolymer of AA, APBA and APAA is easily prepared and immobilized to PS-MA surface fabricating boronic acid affinity layer.•3D structure of immunoreaction spot with an area of 1210 μm * 950 μm is observed on optical profiler.•A disposable boronic acid affinity immunoassay of HbA1c determination is developed on chip with magnetic nanoparticles as label.•For this proposed method, a large detection range of 0.1–10 μg mL−1 with low detection limit of 17.7 μg mL−1 is achieved. It also has excellent repeatability and stability.•The whole analysis process can accomplish in 15 min.This work reports the synthesis of a novel copolymer, poly(AA-PBA-PAA) via an easy one-pot method, the fabrication of boronic acid containing surface layer on silicon chip, and the sandwich immunoassay using magnetic nanoparticles (MNPs) as signal label for fast determination of HbA1c. Poly(AA-PBA-PAA) was synthesized with acrylic acid (AA), 3-aminophenylboronic acid (APBA) and 4-Aminobenzylamine (APAA) by EDC/NHS amidation and RAFT. The molecule structure and molecule weight of the poly(AA-PBA-PAA) were characterized by nuclear magnetic resonance spectroscopy (1H NMR), fourier transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC). The presence of aniline residues allowed the copolymer covalently immobilizing on polystyrene grafted maleic anhydride (PS-MA) coating. We also confirmed the sandwich structure of boronic acid affinity immunoreaction spot on optical microscope and optical profiler. By the means of magnetic nanoparticles counting, a linear range between 0.1–10 μg mL−1 was achieved for the determination of HbA1c. This strategy possesses high sensitivity with detection limit of 17.7 ng mL−1 and excellent stability at 4 °C. The repeatability is evaluated with CV values less than 5% for 10 magnetic nanoparticle number calibrations on the same chip, and less than 10% for 10 different batches. Finally, a comparison of THb and HbA1c determination with different eluents demonstrates significant specificity of this method.Download high-res image (101KB)Download full-size image

A kind of easily assembly self-driving test card was developed for the rapid detection and quantification of heart-type fatty acid binding protein (H-FABP) utilizing time-resolved fluorescence microspheres as signal probes. It was easy to make microfluidic channel structures with double-sided adhesive and cut out of test card substrate and cover based on polymethyl methacrylate (PMMA) material by the laser cutting technique. The membrane of polystyrene containing maleic anhydride functional groups was coated on PMMA plate surface by dip-coating method. Furthermore, the capture antibody was immobilized effectively on PMMA surface by covalent binding with maleic anhydride groups. The cover was treated with plasma treatment to improve the hydrophilic ability, so that the liquid could flow smoothly in the microchannel. The whole analysis process could be completed within 10 min. There was a very good linear correlation between response and H-FABP concentration in the range of 0.5−100 ng mL−1(R2 = 0.9966), and the detection limit was 0.1 ng mL−1 (S/N = 3). The intra-assay precision was less than 10% and the inter-assay precision was less than 15%. This detection method has the advantages such as high sensitivity, fast detection and good accuracy.A self-driving microfluidic time-resolved fluorescence immunoassay test card was developed for rapid detection of heart-type fatty acid binding protein, which has advantages such as low-cost, simple operation, easy processability, well meet the require of clinical application, and could apply to high throughput test for multi-biomarker.

A method for rapid detection and quantification of D-dimer as a biomarker of thrombosis was developed by utilizing giant magnetoresistance (GMR) sensor integrated with microfluidic technique and 100 nm magnetic particles (MPs) as signal probes. The MPs binding on the chip through specific immune reaction were measured by the GMR sensor and the concentration of D-dimer was obtained at the same time. The detection range of this method was from 5 ng mL−1 to 6500 ng mL−1, the detection limit was 5 ng mL−1, the intra relative standard deviation was less than 12% and the inter relative standard deviation was less than 14%. The whole analysis process could be completed within 9 min, and a good linear correlation between the results of GMR biosensor and Sysmex CA1500 was obtained. The method had the advantages such as high sensitivity, fast detection and good accuracy.A method for rapid detection and quantification of D-dimer as a biomarker of thrombosis was developed by utilizing giant magnetoresistance (GMR) sensor integrated with microfluidic technique and with 100 nm magnetic particles (MPs) as signal probes. The detection range of this method was from 5 ng mL−1 to 6500 ng mL−1. The whole analysis process could be completed within 9 min.

By integrated magnetic sensors and microfluidic system, a microfluidic magnetic bioprocessor was developed for the rapid detection of multi-target biomarkers. Three digestive system tumor makers, α-fetoprotein (AFP), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9) were simultaneously detected in immune reactions in the microchannel as a model system to evaluate this multi-target detection system performance. The experiment parameters including injecting flow velocity, immune reaction time and rinsing rate for each step were optimized. The standard curves were established for three tumor markers detection in serum samples, with the detection limits of 0.1 ng mL−1 (CEA), 0.1 ng mL−1 (AFP), 30 U mL−1 (CA19-9) and the dynamic ranges spanning four orders of magnitude. Multi-biomarker analysis could be completed within 30 min, and good linear relations were obtained between the results of magnetic bioprocessor and ELISA method, otherwise, the former had the advantages such as fast detection and high sensitivity.A microfluidic bioprocessor integrated a magnetic tunnel junction (MTJ) device and a microfluidic cartridge has been developed for rapid immunodetection of multi-targets. Three tumor makers (AFP, CEA, CA19-9) were tested simultaneously with the dynamic ranges spanning four orders of magnitude and the advantage of fast detection and high sensitivity.

Transcutaneous immunization (TCI) has many advantages compared with needle-based administrations. But the conventional TCI shows poor permeation of antigens across the skin barrier. In this study, Functional MicroArray (FMA) system was used to poke the skin and increase the permeability, and the hydrogel patch formulation was used as the carrier for transdermal delivery of hepatitis B surface antigen (HBsAg) and cholera toxin B (CTB) as an adjuvant. In vitro permeation of antigen was studied using porcine ear skin and rat abdominal skin. The results showed that FMA system could significantly increase the permeation of HBsAg across skin compared with conventional TCI. HBsAg loaded hydrogel formulation exhibited better antigenic thermostability than the liquid formulation. In vivo immunization studies were performed in mice, and the serum IgG titer, IgG2a/IgG1 ratio were measured. The results showed that TCI with FMA induced more potent immune responses than the groups without FMA pretreatment. CTB adjuvanted TCI group could induce higher IgG titers compared with the group without CTB. Furthermore, TCI group can maintain a longer duration of stable IgG titers compared with the intramuscular injection (IM) group. In conclusion, the FMA/hydrogel system was proved to be a potential vaccination strategy against hepatitis B virus.

La-doped barium-ferrite/polythiophene (LB/PTh) composites have been successfully synthesized by in situ chemical polymerization with ferric chloride (FeCl3) as an initiator. Crystal structure was investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Morphology was investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Electromagnetic of composites was tested by four-probe conductivity tester and vibrating sample magnetometer (VSM). The results of XRD indicated that La3+ had entered into the lattice of barium ferrite. FTIR spectra demonstrated that there were interactions between ferrite particles and PTh. TEM and SEM studies showed that the composites presented the core–shell structure. The electrical conductivity of the composites decreases with the ferrite particles content increase. Under applied magnetic field, nanocomposite exhibited the hysteretic loops of the ferromagnetic behavior. The saturation magnetization and coercivity of nanocomposites varied with the content of ferrite particles.Graphical abstractHighlights► We have firstly prepared the La-doped barium-ferrite/polythiophene composites. ► There were interactions between ferrite particles and polythiophene. ► The conductivity of composites decreases with the ferrite particles content increase. ► Composites exhibited the hystereric loops of the ferromagnetic behavior. ► Ms and Hc of composites varied with the content of ferrite particles.

In vitro and in vivo permeation studies were conducted to evaluate the characteristic of percutaneous administration of high hydrophilic drug L-carnitine (LC) by Functional MicroArray (FMA) painless intradermal delivery system.In vitro study was designed to assess the effects of various skins, donor concentration and hydrogels from different carbomer derivatives on the release of LC in a Franz-type diffusion cell. The LC gel patches with carbomer 980 P were prepared and successfully applied to pharmacokinetic study of SD rats with and without FMA. Intravenous injection and oral administration were performed to support pharmacokinetic calculations and comparison of bioavailability.Enhanced delivery of LC using FMA was achieved in skin of different species in vitro studies. The 750 mg LC gel patches were applied to rats over 6 h, and approximately 27% of loaded dose was transported into rat. A 2.8-fold enhancement of absolute bioavailability for LC with FMA intradermal delivery system was observed compared with oral LC administration in vivo study.Both in vitro and in vivo studies demonstrated that the FMA intradermal delivery system can enhance the delivery and bioavailability of LC.

Two carboxyalkylphosphonic acids (HOOC(CH2)nP(O)(OH)2, n = 2 for 3-PPA and n = 9 for 10-PDA) have been deposited onto 1D zinc oxide (ZnO) nanowires and bare ZnO wafers to form stable self-assembled monolayers (SAMs). The samples were systematically characterized using wettability, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). 3-PPA was bound to the ZnO surfaces mainly through the CO2H headgroup, and 10-PDA formed self-assembled monolayers on the nanoscaled ZnO surface through the PO3H2 headgroups. To verify the potential utilization of the functionalized surfaces in the construction of biosensors or bioelectronics, IgG (immunoglobulin G) protein immobilization through SAM bridging was demonstrated. This work expands the application of phosphonic acid-based surface functionalization on sensing and optoelectronic devices.

An intradermal microdelivery system comprising a wafer having 150-μm long microneedles and an applicator was used for controlled release of insulin. Insulin was topically applied on microneedle-pretreated skin. In vitro percutaneous studies showed that the penetration amount of FITC-Insulin following microneedle pretreatment was enhanced significantly and continued to increase for several hours after the removal of donor phase. In vivo studies on diabetic rats confirmed that the pharmacodynamic profile of percutaneously administrated regular insulin was smooth, with the duration of action comparable to that of subcutaneously injected biphasic insulin. The effects of insulin concentration, duration and area of microneedle treatment on blood glucose lowering were studied in vivo. The results indicated that the duration of microneedle treatment and insulin concentration were key influencing factors to optimize blood glucose control. The extent of blood glucose lowering was in proportion to the area of microneedle treatment.

This paper describes a simple method for preparing protein microarrays that is compatible with high throughput manufacturing. The microarrays were formed by maskless photolithography and pin spotting to study protein adsorption on a fluorinated/methoxy-poly(ethylene glycol) (PEG) self-assembled monolayer (SAM). The mixed nonionic surfactants, Tween20 and PEG200, were utilized to control nonspecific protein adsorption on both of the SAMs. Measurements using double-antibody sandwich quantum dots-linked immunosorbent assay (DAS-QDLISA) showed that the fluorinated SAM could effectively minimize nonspecific adsorption in the presence of Tween 20 and PEG 200 (inhibitors of nonspecific protein adsorption (INSPAs)) while the PEGylated surface was biofouling. Additionally, pin spotting was used to fabricate high-throughput protein arrays on the fluorinated SAM. The results displayed that fluorinated SAM could not only effectively immobilize protein by hydrophobic interactions, but could also resist the other nonspecific adsorption with the INSPA. In this way, protein microarrays would be formed more conveniently and environmentally friendly. It is believed that simple, practical, and high-throughput protein immunosensing could be established with these mixed nonionic surfactants.

A combination method of using microneedle pretreatment and elastic liposomes was developed to increase skin permeation of drugs with high molecular weight and poor water solubility. Docetaxel (DTX, MW = 807.9) was chosen as a model drug. DTX liposomal systems with and without elastic properties were prepared and characterized. The effect of the developed formulations on the permeation of DTX across both rat and porcine skin was investigated in vitro. The combination effect of microneedle pretreatment and elastic liposomes on the permeability of DTX was evaluated using porcine skin in vitro. The following results were obtained: (1) Elastic liposomes loaded with DTX can enhance transdermal delivery of DTX without microneedle treatment. (2) An enhanced transdermal flux (1.3–1.4 μg/cm2/h) for DTX from all liposomal formulations was observed after microneedle treatment. Importantly, the lag time obtained following the application of elastic liposomes through microneedle-treated skin was decreased by nearly 70% compared with that obtained from conventional liposomes. These results suggest that the combination of elastic liposomes with microneedle pretreatment can be a useful method to increase skin permeation of drugs with high molecular weight and poor water solubility.

There is a significant interest in the application of microneedles in intradermal drug delivery systems. Previous studies have demonstrated that skin permeation of drugs can be increased by orders of magnitude with microneedle insertion. In this study, emphasis is placed on the development of low cost, painless intradermal microneedle systems that can enhance the percutaneous drug permeation. Microneedles of octagonal pyramidal shape with the length of 150 μm were employed, and the capabilities of skin permeation enhancement under different delivery conditions were examined. The delivery parameters taken into account included the insertion time and the area of insertion. It was found that when solid microneedle arrays of 150 μm in length were pierced into human dermatomed skin for 5 to 60 s, microconduits with the depth of 50 to 80 μm were created to facilitate the percutaneous permeation of drugs. In percutaneous tests, it was demonstrated that the permeability coefficient of calcein (MW = 622.55) was significantly increased by 104 to 105 times compared to that on intact skin. In terms of biocompatibility, biological evaluation indicated a broad spectrum of safety for the microneedle system. These results suggest that the octagonal pyramidal microneedles can be an effective tool in developing novel intradermal drug delivery system.

Synthesis and characterization of three novel Schiff bases based on calix[4]arene are described. The synthesis of these compounds had been achieved by the condensation of salicylaldehyde derivatives with the amine group of upper rim of de-butylcalix[4]arene in ethanol. The structures of new compounds were confirmed on the basis of IR, 1H NMR, 13C NMR, MS and elementary analysis. Photochromic properties of compounds were studied in CH3CN by UV/vis and fluorescence spectra. These Schiff base–calix[4]arene can be used in certain ‘supermolecular electronic devices’ through combining the photochromic behaviors with others such as non-linear optical or charge transfer properties.

A series of aza crown ether derivatives with or without carboxyl groups in their side arms were synthesized and the former showed deacylation activities toward amino acid p-nitrophenyl ester hydrohalides. Substrate-selective phenomena were also observed. The relationship between the structures and deacylation activities of corresponding compounds suggested a nucleophilic catalytic mechanism. The results partially simulate some aspartic proteinases in the case of catalytic mechanism and are also useful for us to understand the detailed catalytic process of aspartic proteinases.A series of crown ether compounds can selectively complex some specific esters and the carboxyls in their molecules play the role of a hammer just as depicted in the graphic to cleave ester bonds by nucleophilic catalysis, which partially simulates some aspartic proteinases in the case of catalytic mechanisms.

A novel spiropyran derivative carrying a calix[4]arene group has been synthesized through incorporating two spirobenzopyran groups into one 1,3-substituent calix[4]arene derivative. Photochromic properties were studied under alternate irradiation of ultraviolet light and visible light in acetonitrile. Addition of metal ions (such as Mg2+, Ca2+, Eu3+) decreased the first-order thermal decoloration rate constants to different extent. The colored forms of the compound are more stable than the parent 1′,3′,3-trimethyl-6-nitro-8-methanolspirobenzopyran. It provides a method of increasing stability of the merocyanine forms which are of high importance for applications of photochromic materials, especially in the presence of Eu3+. The compound may be applied as photochromic materials for its high thermal stability of colored forms.

This article reports an in vitro study of microneedle-array-enhanced transdermal transport of model drug compounds dispersed in chitosan films. Each microneedle array has 400 out-of-plane, needle-shaped microstructures fabricated using micro-electro-mechanical systems (MEMS) technology to ensure adequate mechanical strength and high precision, and consistency. A nanometer coating on the microneedles ensured the biocompatibility that is important in the application of transdermal drug delivery. Model drugs selected to investigate skin permeation in vitro were calcein, a small molecule (molecular weight, 623 d) that has little skin penetration, and bovine serum albumin (BSA) (molecular weight, 66,000 d), a hydrophilic biological macromolecule. A Franz permeation cell was used to characterize the permeation rate of calcein and BSA through the rat skin. The transdermal transport behavior of BSA was investigated from solid films coated on the surface of microneedle arrays with various chitosan concentrations, film thicknesses, and BSA contents. The BSA permeation rate decreased with the increase of the chitosan concentration; the thicker the film, the slower the permeation rate. In addition, the permeation rate increased with the increase of BSA loading dose. A linear relationship existed between the permeation rate and the square root of the BSA loading dose. Results showed that the chitosan hydrophilic polymer film acts as a matrix that can regulate the BSA release rate. The controlled delivery of BSA can be achieved using the BSA-containing chitosan matrix film incorporated with the microneedle arrays. This will provide a possible way for the transdermal delivery of macromolecular therapeutic agents such as proteins and vaccines.

An improved fabrication of poly(methyl methacrylate) (PMMA)-based capillary electrophoresis microchips has been demonstrated. The microchannel structures on PMMA substrates were generated by one-step hot embossing procedure using a stainless steel template. Hundreds of patterned PMMA substrates have been successfully obtained using the single metal template. Sequent microchannel enclosure with high yield up to 90% was accomplished by a vacuum-assisted thermal bonding method. The results of profilometric scanning of separated substrates showed the dimensions of the channels were well preserved during the bonding process. Finally, analytical functionalities of these PMMA microchips were demonstrated by performing fast electrophoretic separations and high sensitive end-column amperometric detections of dopamine and catechol. The entire fabrication methodology may also be useful for preparation of other thermoplastic microfluidic systems.

The aims of this study were to investigate the utility of solid microneedle arrays (150 µm in length) in enhancing transdermal delivery of peptides and to examine the relationship between peptide permeation rates and D2O flux. Four model peptides were used (Gly–Gln–Pro–Arg [tetrapeptide-3, 456.6 Da], Val–Gly–Val–Ala–Pro–Gly [hexapeptide, 498.6 Da], AC–Glu–Glu–Met–Gln–Arg–Arg–NH2 [acetyl hexapeptide-3, 889 Da] and Cys–Tyr–Ile–Gln–Asn–Cys–Pro–Leu–Gly–NH2 [oxytocin, 1007.2 Da]). The influence of microneedle pretreatment on skin permeation was evaluated using porcine ear skin with Franze diffusion cell. Peptide permeation across the skin was significantly enhanced by microneedle pretreatment, and permeation rates were dependent on peptide molecular weights. A positive correlation between D2O flux and acetyl hexapeptide-3 clearances suggests that convective solvent flow contributes to the enhanced transdermal peptide delivery. It is concluded that solid microneedle arrays are effective devices to enhance skin delivery of peptides.Solid microneedle significantly enhanced the delivery of peptides with low molecular weight through skin and provided a sustained release of the peptides during 24 h. Permeation rate of peptides decreased with the molecular weight increased. Download full-size image

Dissolving microneedles (DMNs) based transdermal delivery is an attractive drug delivery approach with minimal invasion. However, it is still challenging to load poorly water-soluble drugs in DMNs for systemic delivery. The aim of the study was to develop DMNs loaded with artemether (ARM) as a model drug, to enable efficient drug penetration through skin for systemic absorption and distribution. The micro-conduits created by microneedles were imaged by confocal laser scanning microscopy (CLSM), and the insertion depth was suggested to be about 270 μm. The maximum amount of ARM delivered into skin was 72.67 ± 2.69% of the initial dose loaded on DMNs preparation. Pharmacokinetics study in rats indicated a dose-dependent profile of plasma ARM concentrations, after ARM-loaded DMNs treatment. In contrast to intramuscular injection, DMNs application resulted in lower peak plasma levels, but higher plasma ARM concentration at 8 h after administration. There were no significant difference in area under the curve and bioavailability between DMNs group and intramuscular group (P > 0.05). Pharmacodynamics studies performed in collagen-induced arthritis (CIA) rats showed that ARM-loaded DMNs could reverse paw edema, similar to ARM intramuscular injection. In conclusion, developed DMNs provided a potential minimally invasive route for systemic delivery of poorly water-soluble drugs.Download high-res image (147KB)Download full-size image