A wash-free, elution-free and low protein adsorption paper-based material for nucleic acid extraction.

Nucleic acid detection technologies have been widely utilized for various diseases. Conventional laboratory tests are less suitable for use in resource-limited settings as they are time-consuming, high-cost, complex, and heavily dependent on benchtop equipment. Rapid nucleic acid detection methods that consist of rapid nucleic acid extraction steps could overcome these challenges. A paper-based platform has been utilized to develop various rapid nucleic acid extraction methods owing to its cost-effectiveness, portability, and easy-modification. However, the existing paper-based nucleic acid extraction technologies mainly focus on improving the adsorption capacity of nucleic acids without reducing the non-specific adsorption capacity of proteins. In this study, paper-based nucleic acid extraction technology with wash-free, elution-free, and low protein adsorption was developed. The fabrication of paper involves the mixing of polyethylene glycol (PEG)-modified cotton fiber, chitosan (COS)-modified cotton fiber, and cotton fiber to form PEG-modified cotton fiber/chitosan-modified cotton fiber/cotton fiber (PEG-CF/COS-CF/CF) paper by the wet molding method. The result showed that PEG-CF/COS-CF/CF paper has a desirable pore size (23.9 ± 4.03 µm), good mechanical strength (dry: 9.37 Mpa and wet: 0.28 Mpa), and hydrophilicity (contact angle: 42.6° ± 0.36°). NH3+ groups of COS and OH- groups of PEG were observed on its surface and the adsorption efficiency of nucleic acid in TE buffer was 42.48% ± 0.30%. The limit of detection of pure DNA with this PEG-CF/COS-CF/CF paper by qPCR was as low as 25 ng. Additionally, this platform could successfully extract nucleic acid from 30 µL of a saliva sample, highlighting its potential use for clinical sample testing. The proposed paper-based nucleic acid extraction platform shows tremendous potential for disease diagnosis in resource-limited settings.

A nitrocellulose/cotton fiber hybrid composite membrane for paper-based biosensor.

Nitrocellulose (NC) membrane was fabricated and tested for its potential use in various paper-based biosensors for use in point-of-care testing. However, contemporary technologies are complex, expensive, non-scalable, limited by conditions, and beset with potentially adverse effects on the environment. Herein, we proposed a simple, cost-effective, scalable technology to prepare nitrocellulose/cotton fiber (NC/CF) composite membranes. The NC/CF composite membranes with a diameter of 20 cm were fabricated in 15 min using papermaking technology, which contributes to scalability in the large-scale production of these composites. Compared with existing commercial NC membranes, the NC/CF composite membrane is characterized by small pore size (3.59 ± 0.19 µm), low flow rate (156 ± 55 s/40 mm), high dry strength (up to 4.04 MPa), and wet strength (up to 0.13 MPa), adjustable hydrophilic-hydrophobic (contact angles ranged from 29 ± 4.6 to 82.8 ± 2.4°), the good adsorption capacity of protein (up to 91.92 ± 0.07 µg). After lateral flow assays (LFAs) detection, the limit of detection is 1 nM, which is similar to commercial NC membrane (Sartorius CN 140). We envision the NC/CF composite membrane as a promising material for paper-based biosensors of point-of-care testing applications.

Comparison of paper-based nucleic acid extraction materials for point-of-care testing applications.

Cheap, rapid, simple and equipment-free nucleic acid extraction (NAE) is highly preferred for implementing nucleic acid detection at point-of-care (POC). Paper-based NAE materials have been extensively utilized due to their low cost, abundance, portability, biocompatibility and ease of chemical modification. However, it is challenging for users to choose the proper one from existing paper-based NAE materials for specific POC applications, which is determined by their physical and chemical properties. Additionally, building the relationship between the physical and chemical properties and the NAE efficiency of paper-based materials is instructive for development of new paper-based NAE materials. In this study, we first systematically compared the physical and chemical properties of six widely used paper-based NAE materials (namely Whatman filter paper #1, FTA card, FTA elute card, Fusion 5, silica membrane and polyethersulfone (PES) membrane), and then evaluated their NAE efficiency. The obtained results indicated that pore uniformity, wet strength, porosity and functional groups are key parameters to affect the efficiency of NAE. The NAE performance of FTA card is the best with high concentration and purity. Finally, we envision that more cost-effective paper-based NAE materials will be developed for POCT application in the future. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10570-022-04444-6.

Multifunctional Metal-Organic Framework as a Versatile Nanoplatform for Aß Oligomer Imaging and Chemo-Photothermal Treatment in Living Cells.

In view of the close association of ß-amyloid oligomers (AßO) with the clinical development of Alzheimer's disease (AD) symptoms, it is urgent to design a promising sensing and therapeutic strategy that can target AßO for preventing or delaying the onset of AD. Herein, a core-shell nanocomposite CeONP-Res-PCM@ZIF-8/polydopamine (PDA) was synthesized through an in situ encapsulated strategy, in which resveratrol (Res), ceria nanoparticles (CeONPs), and PCM (tetradecanol) were embedded into the ZIF-8/PDA matrix via a water-based mild approach. Using the AßO aptamer, the ability of CeONP-Res-PCM@ZIF-8/PDA/Apt as the fluorescent sensing platform for AßO detection and intracellular imaging was demonstrated. The nanocomposite was high in Res loading (27.5%) and could be activated to release the encapsulated Res upon illumination with NIR through PCM regulation. Moreover, due to the synergetic interactions of PDA, CeONPs, and Res in one system, CeONP-Res-PCM@ZIF-8/PDA/Apt nanocomposites exhibited multifunctional effects on inhibiting Aß aggregation, degrading Aß fibrils, and alleviating Aß-induced oxidative stress and neural apoptosis. These therapeutic effects could be enhanced under NIR irradiation by virtue of the excellent photothermal property of PDA. As far as we know, there is no report of using ZIF-8-based materials for simultaneous sensing and therapeutic applications. This work boosted the development of multifunctional nanoagents for biomedical research studies.

Nanoparticles prepared from pterostilbene reduce blood glucose and improve diabetes complications.

BACKGROUND: Diabetes complications are the leading cause of mortality in diabetic patients. The common complications are decline in antioxidant capacity and the onset of micro-inflammation syndrome. At present, glucose-responsive nanoparticles are widely used, as they can release insulin-loaded ultrafine particles intelligently and effectively reduce blood sugar. However, the toxicology of this method has not been fully elucidated. The plant extracts of pterostilbene (PTE) have a wide range of biological applications, such as antioxidation and inflammatory response improvement. Therefore, we have proposed new ideas for the cross application of plant extracts and biomaterials, especially as part of a hypoglycaemic nano-drug delivery system. RESULTS: Based on the PTE, we successfully synthesised poly(3-acrylamidophenyl boric acid-b-pterostilbene) (p[AAPBA-b-PTE]) nanoparticles (NPs). The NPs were round in shape and ranged between 150 and 250 nm in size. The NPs possessed good pH and glucose sensitivity. The entrapment efficiency (EE) of insulin-loaded NPs was approximately 56%, and the drug loading (LC) capacity was approximately 13%. The highest release of insulin was 70%, and the highest release of PTE was 85%. Meanwhile, the insulin could undergo self-regulation according to changes in the glucose concentration, thus achieving an effective, sustained release. Both in vivo and in vitro experiments showed that the NPs were safe and nontoxic. Under normal physiological conditions, NPs were completely degraded within 40 days. Fourteen days after mice were injected with p(AAPBA-b-PTE) NPs, there were no obvious abnormalities in the heart, liver, spleen, lung, or kidney. Moreover, NPs effectively reduced blood glucose, improved antioxidant capacity and reversed micro-inflammation in mice. CONCLUSIONS: p(AAPBA-b-PTE) NPs were successfully prepared using PTE as raw material and effectively reduced blood glucose, improved antioxidant capacity and reduced the inflammatory response. This novel preparation can enable new combinations of plant extracts and biomaterials to adiministered through NPs or other dosage forms in order to regulate and treat diseases.

Electrochemical Strategy for Analyzing the Co-evolution of Cu2+ and •OH Levels at the Early Stages of Transgenic AD Mice.

As more researchers have acknowledged that the aggregation of amyloid ß (Aß) peptides might only be a pathological phenomenon that appears during the course of Alzheimer's disease (AD), it is therefore of great significance to have a preclinical or an early clinical diagnosis. Cu2+ dyshomeostasis and oxidative stress, such as hydroxyl radical (•OH), are found to be associated with peptide aggregations. However, we still do not know how the levels of Cu2+ and •OH are altered in the brain before massive Aß plaques appear. Herein, we demonstrated the design and application of a sensitive electrochemical sensor to monitor Cu2+ and •OH simultaneously in one system without obvious cross-talk. The electrode was fabricated using black phosphorus-loaded Au (BP-Au) nanoparticles, which were then sequentially linked with DNA1, DNA2-labeled Au (Au-DNA2) nanoparticles, and methylene blue (MB). Cu2+ was first recognized and captured onto the sensor by BP with high selectivity and then produced a reduction current at around -0.01 V. The •OH quantification was established on the cleavage of the hybrid structure between DNA1 and BP-Au upon the appearance of •OH in the phosphate-buffered saline (PBS), leading to the depletion of the voltammetric response of MB around -0.25 V. Good linear correlations were obtained over concentrations of 0.5-127.5 µM for Cu2+ and 0.5-96.0 µM for •OH. Most importantly, the developed sensor was successfully applied to track the variations of the two species in brain tissues from APP/PS1 transgenic AD mice at the early stages before massive Aß plaques appeared.

In vivo monitoring of superoxide anion from Alzheimer's rat brains with functionalized ionic liquid polymer decorated microsensor.

The superoxide anion (O2•-) is an important reactive oxygen species (ROS) in the brain system, which has been associated with the development of many neurological diseases, including Alzheimer's disease (AD). Herein, we introduced a carbon fiber microelectrode (CFME) based in vivo technique for specific and sensitive monitoring of the O2•- radical in the living brains of both normal and AD model rats. Compared with other reported superoxide dismutase (SOD) electrochemical biosensors, the microsensor presented in our work was featured in the coating of a functionalized ionic liquid polymer (PIL) onto PB nanoparticles (PBNPs) and carbon nanotubes (CNT). It was demonstrated that the cationic and carboxyl-rich PILs provided abundant interaction sites with SOD to prevent enzyme leakage from sensor, which was beneficial for the enhancement of sensitivity. Additionally, CCK-8 assay and autoxidation of pyrogallol tests showed that MCF-7 cells maintained a high viability after incubated with PIL and most of the SOD bioactivity was retained in the presence of PIL, which implied the PIL itself possessed an excellent biocompatibility. These properties allow the sensor to track the fluctuation of O2•- levels in vivo between normal and AD rats. This is the first report on application of functionalized PIL to reveal the O2•- related pathological process of AD.

Obesity increases the risk of renal involvement in children with Henoch-Schönlein purpura.

UNLABELLED: The main aim of this study was to evaluate the relationship between obesity and renal involvement in children with Henoch-Schönlein purpura (HSP). A retrospective study of 141 pediatric patients with HSP was conducted in our hospital. The clinical data of all patients were collected from the electronic medical record management system from January 2010 to June 2014. The possible risk factors of renal involvement, especially obesity, were analyzed using univariate and multivariate analyses. Renal involvement occurred in 45/141 of the patients. A univariate analysis showed that an age more than 7 years at onset, persistent purpura, obesity, time from symptoms onset to diagnosis more than 14 days, and decreased C3 all increased the risk of renal involvement in HSP. The forward stepwise logistic regression analysis indicated obesity (odds ratio (OR) 4.43, 95 % confidence interval (CI) 1.896 to 10.358), age more than 7 years at onset (OR 2.81, 95 % CI 1.142 to 6.907), and persistent purpura (OR 2.57, 95 % CI 1.119 to 5.909) were independent risk factors for renal involvement. CONCLUSIONS: Our results show that obesity can increase the hazard of renal involvement in children with HSP and reconfirm that older age at onset and persistent purpura are the independent risk factors for renal involvement. WHAT IS KNOWN: • There have been some reports that obesity was associated with the development of renal injury. • It is not clear whether obesity can increase the risk of renal involvement in children with HSP. What is New: • The main finding of this study is that obesity can increase the hazard of renal involvement in children with HSP.

Effect of Xeroderma pigmentosum complementation group F polymorphisms on gastric cancer risk and associations with H.pylori infection.

We conducted a hospital case-control study by genotyping four potential functional single nucleotide polymorphisms (SNPs) to assess the association of Xeroderma pigmentosum complementation group F (XPF) with gastric cancer susceptibility, and role of XPF polymorphisms in combination with H.pylori infection in risk definition. A total of 331 patients with gastric cancer and 355 controls were collected. Four SNPs of XPF, rs180067, rs1799801, rs2276466 and rs744154, were genotyped by Taqman real-time PCR method with a 7900 HT sequence detector system. The gastric cancer patients were more likely to have smoking habit, a family history of cancer and H.pylori infection. We did not find any significant difference in the genotype distributions of XPF rs180067, rs1799801, rs2276466 and rs744154 between cases and controls. However, multivariate logistic analysis showed a non-significant decreased risk in patients carrying rs180067 G allele, rs1799801 T allele or rs2276466 T allele genotypes. A non-significant increased risk of gastric cancer was found in individuals carrying the rs744154 GG genotype. Stratification by H.pylori infection and smoking was not significantly different in polymorphisms of XPF rs180067, rs1799801, rs2276466 and rs744154. The four XPF SNPs did not show significant interaction with H.pylori infection and smoking status (P for interaction was 0.35 and 0.18, respectively). Our study indicated that polymorphisms in rs180067, rs1799801, rs2276466 and rs744154 may affect the risk of gastric cancer but further large sample size studies are needed to validate any association.