An antifouling electrochemical aptasensor based on a polydopamine-polyzwitterion copolymer for tetracycline analysis.

Matrix interference resulting from the nonspecific adsorption of non-target components, particularly proteins (fouling), onto sensor surfaces poses a persistent challenge in electrochemical detection of food hazards. The development of antifouling sensor surfaces presents a viable approach to mitigate nonspecific adsorption. In this study, a novel antifouling electrochemical aptasensor, utilizing a zwitterionic polymer, was developed for the sensitive, accurate, and selective detection of tetracycline (TC) in milk. This sensor employs a poly (dopamine)-poly (sulfobetaine methacrylate) (PDA-PSBMA) antifouling copolymer, which is synthesized through an in-situ initiated copolymerization of dopamine on the sensor's surface. Subsequently, the thiol-containing aptamers were immobilized onto the PDA-PSBMA coating through a Michael addition reaction with the poly(dopamine). The resulting antifouling electrochemical aptasensor exhibited robust antifouling performance in various single protein solutions and diluted milk samples, coupled with sensitive and selective recognition of TC. The sensor demonstrated a broad linear response range of 0.1-1000.0 ng mL-1 and a low limit of detection (LOD) of 68.0 pg mL-1. The antifouling electrochemical aptasensor proved effective in assaying TC in diluted milk, with recoveries ranging from 100.0 % to 104.4 %, eliminating the need for additional pretreatments due to its exceptional resistance to nonspecific adhesion.

Adhesive, antibacterial and double crosslinked carboxylated polyvinyl alcohol/chitosan hydrogel to enhance dynamic skin wound healing.

An available dressing material which promotes skin tissue repair is of significant importance for public health. Moreover, dynamic wounds have special requirements for hydrogel dressings due to their motion state. Correspondingly, a double crosslinked hydrogel was prepared based on amide and coordination bonds from carboxylated polyvinyl alcohol (PC) and chitosan (CS)/Fe3+. The hydrogel exhibited excellent swelling ratio and suitable biodegradability, which is beneficial to the tissue repair. The results showed that hydrogels with crosslinked structure possessed better unique properties, such as stronger mechanical (78 kPa of G') and adhesion properties, and shorter self-healing time (5 mins), the change of which was consistent with dynamic wounds. The hydrogel exhibited not only antibacterial activity (98 % fatality rate), but also superior hemostatic capacity during the wound healing process. In addition, the hydrogel could shorten skin healing time to 14 days, and obviously accelerated skin structure reconstruction by promoting angiogenesis and collagen deposition. Therefore, double crosslinked hydrogel is a promising dynamic wound dressing.

Flexible, high-strength and multifunctional polyvinyl alcohol/MXene/polyaniline hydrogel enhancing skin wound healing.

Nature-inspired flexible and multifunctional hydrogels are ideal materials for tissue repair. High-strength, wear-resistant, antibacterial and conductive hydrogels can potentially be applied in skin healing. However, their use is often hindered by problems including poor mechanical properties and conductivity. Herein, high-strength and conductivity and antibacterial polyvinyl alcohol (PVA) hydrogels with Ti3C2Tx (MXene) and polyaniline (PANI) have been developed to enhance skin wound healing. MXene strengthens the hydrogen bonds between PVA molecules and provides antibacterial ability lighted by near-infrared (NIR). PANI acts as an electric conductor and forms chemical bonds via polymerization with PVA to further enhance the mechanical properties of hydrogels. The PVA/MXene/PANI (PMP) hydrogels exhibit excellent mechanical properties (with a tensile strength of 4.1 MPa and a fracture energy of 130 kJ m-2), high electrical conductivity (0.22 S m-1) and antibacterial ability. The hydrogels significantly inhibit bacterial activity in vitro and vivo. Meanwhile, the hydrogels promote proliferation and enhance the migration of cells by electrical stimulation (ES). In addition, PMP hydrogels obviously accelerate skin wound healing by promoting angiogenesis and collagen deposition. Therefore, PMP multifunctional hydrogels are a prospective wearproof material for wound-healing dressings.

Saliva 1,5-anhydroglucitol is associated with early-phase insulin secretion in Chinese patients with type 2 diabetes.

INTRODUCTION: Saliva collection is a non-invasive test and is convenient. 1,5-anhydroglucitol (1,5-AG) is a new indicator reflecting short-term blood glucose levels. This study aimed to explore the relationship between saliva 1,5-AG and insulin secretion function and insulin sensitivity. RESEARCH DESIGN AND METHODS: Adult patients with type 2 diabetes who were hospitalized were enrolled. Based on blood glucose and C-peptide, homeostasis model assessment 2 for ß cell secretion function, C-peptidogenic index (CGI), △2-hour C-peptide (2hCP)/△2-hour postprandial glucose (2hPG), ratio of 0-30 min area under the curve for C-peptide and area under the curve for glucose (AUCCP30/AUCPG30), and AUC2hCP/AUC2hPG were calculated to evaluate insulin secretion function, while indicators such as homeostasis model assessment 2 for insulin resistance were used to assess insulin sensitivity. RESULTS: We included 284 subjects (178 men and 106 women) with type 2 diabetes aged 20-70 years. The saliva 1,5-AG level was 0.133 (0.089-0.204) µg/mL. Spearman's correlation analysis revealed a significantly negative correlation between saliva 1,5-AG and 0, 30, and 120 min blood glucose, glycated hemoglobin A1c, and glycated albumin (all p<0.05), and a significantly positive association between saliva 1,5-AG and CGI (r=0.171, p=0.004) and AUC CP30 /AUC PG30 (r=0.174, p=0.003). The above correlations still existed after adjusting for age, sex, body mass index, and diabetes duration. In multiple linear regression, saliva 1,5-AG was an independent factor of CGI (standardized ß=0.135, p=0.015) and AUC CP30 /AUC PG30 (standardized ß=0.110, p=0.020). CONCLUSIONS: Saliva 1,5-AG was related to CGI and AUCCP30/AUCPG30 in patients with type 2 diabetes. TRIAL REGISTRATION NUMBER: ChiCTR-SOC-17011356.

Aptamer-gold nanoparticle doped covalent organic framework followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for selective enrichment and detection of human insulin.

In this work, we introduced an aptamer modified Au nanoparticles doped covalent organic frameworks composite (IBAs-AuNPs/COF) to improve the property of selective enrichment of insulin from serum samples. The Au nanoparticles were immobilized on imine-based COF by in-situ reduction reaction via mussel inspired polydopamine coating, and then sulfhydryl-containing aptamers were bonded to the surface of AuNPs through an Au-S linkage. Due to the excellent adsorption property of COF and specific recognition between insulin and IBAs, the IBAs-AuNPs/COF composites show selective and satisfactory extraction property to insulin in serum samples. Excellent specifity was obtained for insulin in the presence of 50-fold interfering substances including human immunoglobulin, lysozyme and biotin. The concentrations of insulin in the range of 1.0 to 50.0 µg L-1 show good linear relationship (R2 = 0.9917) with limit of detection and limit of quantitation of 0.28 µg L-1 and 0.93 µg L-1, respectively. Then, the IBAs-AuNPs/COF composites were applied to enrich insulin in serum samples followed by analysis with matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS). After the recovery experiment, the developed method shows good recoveries in range of 91.6%-112.4% with low RSD value (2.4%-9.4%, n = 3) for diabetic and healthy serum samples. The developed IBAs-AuNPs/COF composites propose a new perspective for selective and efficient enrichment of biomarkers in serum samples by functionalized COF.

Diabetes Screening: Detection and Application of Saliva 1,5-Anhydroglucitol by Liquid Chromatography-Mass Spectrometry.

CONTEXT: Unlike other commonly used invasive blood glucose-monitoring methods, saliva detection prevents patients from suffering physical uneasiness. However, there are few studies on saliva 1,5-anhydroglucitol (1,5-AG) in patients with diabetes mellitus (DM). OBJECTIVE: This study aimed to evaluate the effectiveness of saliva 1,5-AG in diabetes screening in a Chinese population. DESIGN AND PARTICIPANTS: This was a population-based cross-sectional study. A total of 641 subjects without a valid diabetic history were recruited from September 2018 to June 2019. Saliva 1,5-AG was measured with liquid chromatography-mass spectrometry. MAIN OUTCOME MEASURES: DM was defined per American Diabetes Association criteria. The efficiency of saliva 1,5-AG for diabetes screening was analyzed by receiver operating characteristic curves, and the optimal cutoff point was determined according to the Youden index. RESULTS: Saliva 1,5-AG levels in subjects with DM were lower than those in subjects who did not have DM (both P < .05). Saliva 1,5-AG was positively correlated with serum 1,5-AG and negatively correlated with blood glucose and glycated hemoglobin (HbA1c) (all P < .05). The optimal cutoff points of saliva 1,5-AG0 and 1,5-AG120 for diabetes screening were 0.436 µg/mL (sensitivity: 63.58%, specificity: 60.61%) and 0.438 µg/mL (sensitivity: 62.25%, specificity: 60.41%), respectively. Fasting plasma glucose (FPG) combined with fasting saliva 1,5-AG reduced the proportion of people who required an oral glucose tolerance test by 47.22% compared with FPG alone. CONCLUSION: Saliva 1,5-AG combined with FPG or HbA1c improved the efficiency of diabetes screening. Saliva 1,5-AG is robust in nonfasting measurements and a noninvasive and convenient tool for diabetes screening.

Biomimetic mineralized strontium-doped hydroxyapatite on porous poly(l-lactic acid) scaffolds for bone defect repair.

INTRODUCTION: poly(l-lactic acid) (PLLA) has been approved for clinical use by the US Food and Drug Administration (FDA); however, their stronger hydrophobicity and relatively fast degradation rate restricted their widespread application. In consideration of the composition of bone, the inorganic-organic composite has a great application prospect in bone tissue engineering. Many inorganic-organic composite scaffolds were prepared by directly mixing the active ingredient, but this method is uncontrolled and will lead to lack of homogeneity in the polymer matrix. Strontium (Sr) is an admirable addition to improve the bioactivity and bone induction of hydroxyapatite (HA). To our knowledge, the application of biomimetic mineralized strontium-doped hydroxyapatite on porous poly(l-lactic acid) (Sr-HA/PLLA) scaffolds for bone defect repair has never been reported till date. Biomimetic mineralized Sr-HA/PLLA porous scaffold was developed in this study. The results indicated that the Sr-HA/PLLA porous scaffold could improve the surface hydrophobicity, reduce the acidic environment of the degradation, and enhance the osteoinductivity; moreover, the ability of protein adsorption and the modulus of compression were increased. The results also clearly showed the effectiveness of the Sr-HA/PLLA porous scaffold in promoting cell adhesion, proliferation, and alkaline phosphatase (ALP) activity. The micro computed tomography (micro-CT) results showed that more new bones were formed by Sr-HA/PLLA porous scaffold treatment. The histological results confirmed the osteoinductivity of the Sr-HA/PLLA porous scaffold. The results suggested that the Sr-HA/PLLA porous scaffold has a good application prospect in bone tissue engineering in the future. PURPOSE: The purpose of this study was to promote the bone repair. MATERIALS AND METHODS: Surgical operation of rabbits was carried out in this study. RESULTS: The results showed that formation of a large number of new bones by the Sr-HA/PLLA porous scaffold treatment is possible. CONCLUSION: Biomimetic mineralized Sr-HA/PLLA porous scaffold could effectively promote the restoration of bone defects in vivo.

Sex-dependent effects on gut microbiota regulate hepatic carcinogenic outcomes.

Emerging evidence points to a strong association between sex and gut microbiota, bile acids (BAs), and gastrointestinal cancers. Here, we investigated the mechanistic link between microbiota and hepatocellular carcinogenesis using a streptozotocin-high fat diet (STZ-HFD) induced nonalcoholic steatohepatitis-hepatocellular carcinoma (NASH-HCC) murine model and compared results for both sexes. STZ-HFD feeding induced a much higher incidence of HCC in male mice with substantially increased intrahepatic retention of hydrophobic BAs and decreased hepatic expression of tumor-suppressive microRNAs. Metagenomic analysis showed differences in gut microbiota involved in BA metabolism between normal male and female mice, and such differences were amplified when mice of both sexes were exposed to STZ-HFD. Treating STZ-HFD male mice with 2% cholestyramine led to significant improvement of hepatic BA retention, tumor-suppressive microRNA expressions, microbial gut communities, and prevention of HCC. Additionally the sex-dependent differences in BA profiles in the murine model can be correlated to the differential BA profiles between men and women during the development of HCC. These results uncover distinct male and female profiles for gut microbiota, BAs, and microRNAs that may contribute to sex-based disparity in liver carcinogenesis, and suggest new possibilities for preventing and controlling human obesity-related gastrointestinal cancers that often exhibit sex differences.