Mild hyperthermia enhanced synergistic uric acid degradation and multiple ROS elimination for an effective acute gout therapy.

BACKGROUND: Acute gouty is caused by the excessive accumulation of Monosodium Urate (MSU) crystals within various parts of the body, which leads to a deterioration of the local microenvironment. This degradation is marked by elevated levels of uric acid (UA), increased reactive oxygen species (ROS) production, hypoxic conditions, an upsurge in pro-inflammatory mediators, and mitochondrial dysfunction. RESULTS: In this study, we developed a multifunctional nanoparticle of polydopamine-platinum (PDA@Pt) to combat acute gout by leveraging mild hyperthermia to synergistically enhance UA degradation and anti-inflammatory effect. Herein, PDA acts as a foundational template that facilitates the growth of a Pt shell on the surface of its nanospheres, leading to the formation of the PDA@Pt nanomedicine. Within this therapeutic agent, the Pt nanoparticle catalyzes the decomposition of UA and actively breaks down endogenous hydrogen peroxide (H2O2) to produce O2, which helps to alleviate hypoxic conditions. Concurrently, the PDA component possesses exceptional capacity for ROS scavenging. Most significantly, Both PDA and Pt shell exhibit absorption in the Near-Infrared-II (NIR-II) region, which not only endow PDA@Pt with superior photothermal conversion efficiency for effective photothermal therapy (PTT) but also substantially enhances the nanomedicine's capacity for UA degradation, O2 production and ROS scavenging enzymatic activities. This photothermally-enhanced approach effectively facilitates the repair of mitochondrial damage and downregulates the NF-κB signaling pathway to inhibit the expression of pro-inflammatory cytokines. CONCLUSIONS: The multifunctional nanomedicine PDA@Pt exhibits exceptional efficacy in UA reduction and anti-inflammatory effects, presenting a promising potential therapeutic strategy for the management of acute gout.

Structure-Dependent Nontraditional Intrinsic Fluorescence of Aliphatic Hyperbranched Polyureas.

The nontraditional intrinsic fluorescence (NTIF) of polymers containing heteroatoms has gained considerable attention due to its promising applications in label-free bioimaging. Aliphatic hyperbranched polyureas (aBPUs), which have recently shown great promise in the field of nanomedicine, bear controllable urea groups distributed on the branch points and thus are potential candidate luminogens. However, their NTIF properties and how their structures influence the NTIF properties have not been illustrated yet. Here, we addressed these issues by synthesizing a series of aBPUs with different degrees of branching (DBs) or different modifications. aBPUs exhibited an obvious NTIF phenomenon and with the increase of DBs, the NTIF enhanced as well. Chemical modifications either at the branching ends or in the interior of aBPUs could affect the NTIF performances, which were highly dependent on the types of modification. Disruption of the intra-/intermolecular hydrogen-bonding interactions decreased the NTIF. In addition, poly(ethylene glycol) (PEG)-modified aBPUs could self-assemble into nanospheres, and the formation of nanoassembly led to 89% enhancement on NTIF compared with the homogeneous solution of aBPUs-PEG in dimethylformamide (DMF). Finally, aBPUs-PEG nanoassembly demonstrated a capability in realizing label-free material imaging in vitro. These results shed light on the rational design of the polymer structures to achieve desired fluorescence with unconventional luminophores.

A Self-Healing Polymer with Fast Elastic Recovery upon Stretching.

The design of polymers that exhibit both good elasticity and self-healing properties is a highly challenging task. In spite of this, the literature reports highly stretchable self-healing polymers, but most of them exhibit slow elastic recovery behavior, i.e., they can only recover to their original length upon relaxation for a long time after stretching. Herein, a self-healing polymer with a fast elastic recovery property is demonstrated. We used 4-[tris(4-formylphenyl)methyl]benzaldehyde (TFPM) as a tetratopic linker to crosslink a poly(dimethylsiloxane) backbone, and obtained a self-healing polymer with high stretchability and fast elastic recovery upon stretching. The strain at break of the as-prepared polymer is observed at about 1400%. The polymer can immediately recover to its original length after being stretched. The damaged sample can be healed at room temperature with a healing efficiency up to 93% within 1 h. Such a polymer can be used for various applications, such as functioning as substrates or matrixes in soft actuators, electronic skins, biochips, and biosensors with prolonged lifetimes.

Quaternary ammonium-tethered hyperbranched polyurea nanoassembly synergized with antibiotics for enhanced antimicrobial efficacy.

The effective transportation of antibiotics to bacteria embedded within a biofilm consisting of a dense matrix of extracellular polymeric substances is still a challenge in the treatment of bacterial biofilm associated infections. Here, we developed an antibiotic nanocarrier constructed from quaternary ammonium-tethered hyperbranched polyureas (HPUs-QA), which showed high loading capacity for a model antibiotic, rifampicin, and high efficacy in the transportation of rifampicin to biofilms. The rifampicin-loaded HPUs-QA nanoassembly (HPUs-Rif/QA) demonstrated a synergistic antimicrobial effect in killing planktonic bacteria and eradicating the corresponding biofilms. Compared to the treatment of bacteria-infected chronic wounds by either HPUs-QA or rifampicin alone, HPUs-Rif/QA showed superior efficacy in promoting wound healing by more effectively inhibiting bacteria colonization. This study highlights the potential of the HPUs-QA nanoassembly in synergistic action with antibiotics for the treatment of biofilm associated infections.

Hydrophobic polyethylene film prepared by film blowing process for preservation of fried shrimp rolls.

Hydrophobic coatings have wide applications, but face challenges in food flexible packaging in terms of poor adhesion and inadequate wear resistance. Health hazards and poor adhesion drive the search for novel hydrophobic coatings substitutes. Here, we introduced rationally synthesized carnauba wax-SiO2 microspheres as a component to composite polyethylene (PE) film construction, and created a wear-resistant hydrophobic composite PE film via the blown film technique. The resultant hydrophobic composite film demonstrated an enhanced water contact angle from 86° to above 100°, coupled with favorable mechanical properties such as wear resistance, tensile strength and effective barrier performance against water vapor and oxygen. Upon implementation in the preservation of a Cantonese delicacy, Chaoshan fried shrimp rolls, it was observed that at 25 °C, the carnauba wax-SiO2-PE composite packaging film extended the shelf life of the product by 3 days compared to pure PE film.

ß-methasone-containing biodegradable poly(lactide-co-glycolide) acid microspheres for intraarticular injection: effect of formulation parameters on characteristics and in vitro release.

A sustained drug release system based on the injectable poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with ß-methasone was prepared for localized treatment of rheumatic arthritis. The microscopy and structure of microspheres were characterized by scanning electron microscope (SEM) and Fourier transform infrared (FTIR). The effects of various formulation parameters on the properties of microspheres and in vitro release pattern of ß-methasone were also investigated. The results demonstrated that increase in drug/polymer ratio led to increased particle size as well as drug release rate. Increase in PLGA concentration led to increased particle size, but decreased burst release. The drug encapsulation efficiency increased sharply by increasing polyvinyl alcohol (PVA) concentration in the aqueous phase from 1.5 to 2.0%. ß-methasone release rate decreased considerately with decreasing OP (organic phase)/AP (aqueous phase) volume ratio. Stirring rate had significantly influence on the particle size and encapsulation efficiency. Independent of formulation parameters, ß-methasone was slowly released from the PLGA microspheres over 11 days. The drug release profile of high drug loaded microspheres agree with Higuchi equation with a release mechanism of diffusion and erosion, that of middle drug loaded microspheres best agreed with Hixcon-Crowell equation and controlled by diffusion and erosion as well. The low drug loaded microspheres well fitted to logarithm normal distribution equation with mechanism of purely Fickian diffusion.

Silicon carbide catalytic ceramic membranes with nano-wire structure for enhanced anti-fouling performance.

Membrane fouling is a critical challenge for current ceramic membranes, which suffer from low flux and insufficient removal. Development of self-cleaning catalytic ceramic membranes is promising to address this challenge. Herein, we design heterogeneous silicon carbide ceramic membranes featuring a novel structure of g-C3N4-decorated ß-SiC nano-wire catalytic functional layer, which enables enhanced anti-fouling self-cleaning performance. At chemical harsh (alkaline or especially acidic) conditions, the nano-wire membrane exhibits catalysis-enhanced removal performance for organic contaminants. Unlike conventional particle-packing membrane structure, such a nano-wire network membrane structure has not only high porosity (56.1%), but exceptional water permeance (110 L·m-2·h-1·bar-1) and removal (100%) of organic substance under simulated sunlight, outperforming state-of-the-art organic membranes and ceramic membranes. Superoxide radical (∙O2-) was experimentally confirmed to be major reactive species responsible for self-cleaning function. We also propose a catalytic mechanism model with radical formation pathway, enabled by the as-formed g-C3N4@ß-SiC heterojunction structure with reduced electron-hole recombination. This work would provide new insights into not only rational design of next-generation ceramic membranes with self-cleaning function but also more applications of efficient treatment of refractory wastewaters containing degradable organic substances by using such membranes.

Inhibition of starch digestion: The role of hydrophobic domain of both α-amylase and substrates.

The physicochemical mechanism of starch digestion is very complicated since it may be affected by the non-valence interactions of the amylase inhibitor with the substrate or the enzyme. The role of hydrophobic interaction in the process of starch digestion is not clear. In this study, pluronics (PLs) with different hydrophobicity were used as model amphiphilic compounds to study their inhibition on starch digestion using multi-spectroscopic methods. The results showed that the hydrophobic nature of PLs changed starch structure, but it had a greater effect on the structure of α-amylase by exposing more tryptophan residues and increasing α-helix and ß-sheet contents. Further investigation by using different chain-length fatty acids confirmed the results. The finding in this study is informative to design and fabricate α-amylase inhibitors for controlling starch digestion at the molecular level.

Infectious intracranial aneurysm: endovascular treatment with onyx case report and review of the literature.

Intracranial infectious (mycotic) aneurysms are very rare, but continue to be challenging and technically demanding, which need careful diagnosis and therapy. We present an 18-year-old man with an intracranial infectious aneurysm located on the left posterior cerebral artery who was successfully treated with endovascular embolization by a liquid embolic agent (onyx) and who recovered well.

[Tissue engineering vascularized bone repairing segmental femoral bone defects in rabbits].

OBJECTIVE: To investigate the effectiveness and mechanism of tissue engineering vascularized bone in repairing segmental femoral bone defects in rabbits. METHODS: Thirty-two rabbits were randomized into two groups (n = 16 each). A segmental and critical bone defect of 15 mm in length was made at left femur. In experimental group, the tissue engineering bone constructed from autologous bone marrow mesenchymal stem cells plus beta-tricalcium phosphate (beta-TCP) and vascular bundle was implanted into bony defect. In control group, there was no implantation of vascular bundle. Animals were sacrificed at 2, 4, 8 and 12 weeks post-implantation respectively. Histological observation was conducted to determine the process of new bone formation and remodeling. The expression of vascular endothelial growth factor (VEGF) in new bone was measured by immunohistochemistry, real-time PCR and Western blot. RESULTS: As indicated by histological observations over time, new bone formation increased in both groups. It was better in the experimental group than the control group at the beginning of 4 weeks. The expression level of VEGF gradually decreased in each group after an initial rise. And the expression of VEGF was significantly higher than the control group after implantation at all time points and peaked at 4 weeks. CONCLUSION: Tissue engineering vascularized bone accelerates bone repair in critical size defect model of femur in rabbit. Implantation of vascular bundle can promote the secretion of VEGF. And VEGF is an essential mediator of both angiogenesis and ossification.

[Study on separation and purification of total alkaloids and mesaconitine with X - 5 macroporous resin].

OBJECTIVE: To study systematically the factors which affect separation and purification of the total alkaloids and mesaconitine with X -5 macroporous resin. METHOD: With the content of the total alkaloids and mesaconitine as parameters, the optimum condition of absorption and elution were studied in the process of the purification with X -5 macroporous resin. RESULT: The X - 5 macroporous resin yielded the best separating efficiency when the concentration of the extracted solution was 1 g raw material per 1 mL, pH 12.0, the absorptive time of 6 hour and the volume of 95% ethanol (7BV pH 8) as the eluant; X -5 macroporous resins was used five times in a reproducible way. The rate of extraction and content of the total alkaloid were 80% and 30% respectively after purification with X - 5 macroprous resin. CONCLUSION: The method can increase the purity of mesaconitine and total alkaloids.

Protective effects of drag-reducing polymers on ischemic reperfusion injury of isolated rat heart.

Drag-reducing polymers (DRPs) are blood-soluble macromolecules that can increase blood flow and reduce vascular resistance. The purpose of the present study was to observe the effect of DRPs on ischemic reperfusion (I/R) injury of isolated rat hearts. Experiments were performed on isolated rat hearts subjected to 30 min of ischemia followed by 90 min of reperfusion in Langendorff preparations. Adult Wistar rats were divided into the following five groups: control group, I/R group, group III (I/R and 2×10(-7)  g/ml PEO reperfusion), group IV (I/R and 1×10(-6)  g/ml PEO reperfusion), and group V (I/R and 5×10(-6)  g/ml PEO reperfusion). Left ventricular end-diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP), maximum rate of ventricular pressure increase and decrease ( ± dp/dtmax), heart rate (HR) and coronary flow were measured. Lactate dehydrogenase (LDH) and creatine kinase (CK) activity and coronary flow, myocardial infarction size and cardiomyocytes apoptosis were also assayed. Our results showed that PEO decreased LVEDP and increased LVSP, ± dP/dtmax in group IV and group V compared with the I/R group (all P <  0.05). The coronary flow significantly increased and the activities of LDH and CK in the coronary flow significantly decreased in group IV and group V compared with those in the I/R group (all P <  0.05). Cell apoptosis and myocardial infarction size were reduced in group IV and group V compared with the I/R group (all P <  0.05). Collectively, these results suggested that DRPs had a protective effect on cardiac I/R injury of isolated rat hearts and it may offer a new potential approach for the treatment of acute ischemic heart diseases.

Aqueous two-phase extraction combined with chromatography: new strategies for preparative separation and purification of capsaicin from capsicum oleoresin.

Capsaicin was preparatively separated and purified from capsicum oleoresin with a new method combined with aqueous two-phase extraction (ATPE) and chromatography. Screening experiments of ATPE systems containing salts and hydrophilic alcohols showed that potassium carbonate/ethanol system was the most suitable system for capsaicin recovery among the systems considered. Response surface methodology was used to determine an optimized aqueous two-phase system for the extraction of capsaicin from capsaicin oleoresin. In a 20 % (w/w) ethanol/22.3 % (w/w) potassium carbonate system, 85.4 % of the capsaicin was recovered in the top ethanol-rich phase while most oil and capsanthin ester were removed in the interphase. The capsaicinoid extract was then subjected to two chromatographic steps using D101 macroporous resin and inexpensive SKP-10-4300 reverse-phase resin first applied for the purification of capsaicin. After simple optimization of loading/elution conditions for D101 macroporous resin chromatography and SKP-10-4300 reverse-phase resin chromatography, the purities of capsaicin were improved from 7 to 85 %. In the two chromatography processes, the recoveries of capsaicin were 93 and 80 % respectively; the productivities of capsaicin were 1.86 and 4.2 (g capsaicin/L resin) per day respectively. It is worth mentioning that a by-product of capsaicin production was also obtained with a high purity (90 %).

Isoniazid conjugated poly(lactide-co-glycolide): long-term controlled drug release and tissue regeneration for bone tuberculosis therapy.

Bone tuberculosis (TB) is one of the most common extrapulmonary TB. Effective integration of chemotherapy and bone regeneration is an optimal solution for bone TB therapy. Herein, we produce a composite scaffold drug delivery system fabricated with an isoniazid conjugated star poly(lactide-co-glycolide) (PLGA-INH4) and ß-TCP. The cytological assay indicated the composite system possesses good biocompatibility. The in vitro and in vivo drug release evaluations showed that the composite system can intactly release the pristine INH and maintain effective INH concentration in a controlled manner for more than 100 days, and achieve high localized drug concentration and low systemic drug concentration. The rabbit radius repair experiment testified the scaffold has good bone regeneration capacity. Our work demonstrate the composite system can simultaneously achieve localized long-term drug controlled release and bone regeneration, which provides a promising route for improved bone TB treatment.

[A exploration and study of the relationships of hand-foot-mouth disease (HFMD) and the climate].

OBJECTIVE: To explore and study the relationships between the popularity of HFMD and the climate in Qinhuangdao city. METHODS: HFMD cases were collected on a ten-day basis in 2009 in Qinhuangdao city. At the same time, the data about Qinhuangdao's ten-day average temperature and average humidity were provided by the Qinhuangdao Meteorological bureau. Then the collected data were analysed using the great data analysis function in the EXCELE software. RESULTS: The results showed that the disease of HFMD had a positive relationship with seasons. The cases of HFMD began to rise at the last ten days of March and rised dramatically at the middle ten days of April; In July, the cases of HFMD arrived at peak and then decline gradually. The cases of HFMD in October were quite similar to the cases of HFMD in March. Then in November, the cases of HFMD declined rapidly. All these evidences suggested that the peak seasons of HFMD were Spring and Summer. CONCLUSION: The situations of HFMD had a significant positive relationship with the conditions of climate, such as high temperature and high humidity.

Degradation behavior and biocompatibility of PEG/PANI-derived polyurethane co-polymers.

A series of polyurethane (PU) co-polymers with designable molecular weight between cross-linking dots was synthesized by a hydrogen transfer polymerization route from polyaniline (PANI), poly(ethylene glycol) (PEG), various curing agents and chain extenders using dibutyltin dilaurate as a catalyst. Their swelling, hydrophilicity, degradation and biocompatibility were inspected and assessed based on different degrees of polymerization of PANI and PEG, and their component proportion. Fourier transformation infrared spectrometry (FT-IR), (1)H-NMR spectroscopy, scanning electron microscopy (SEM), gel-permeation chromatography (GPC) and goniometry were used to characterize the structure and surface morphology of the synthesized PEG/PANI-based PU co-polymers, PU residues after degradation and degraded polymers at different time periods of hydrolysis. The thermal properties, aggregate structure and surface microstructure were examined by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and atomic force microscopy (AFM). Hemolysis, static platelet adhesion, dynamic clotting measurements and MTT assays were adopted to evaluate the hemo- or cytocompatibility. The experimental results indicated that these polymers exhibit various degrees of micro-phase separation, depending on the concentration and degree of polymerization of PANI, molecular weight of PEG, type of curing agent and chain extender, which further influence their swelling, hydrophilicity, degradable properties and biological performances in vitro. The incorporation of PANI and PANI* in co-polymers led to decreased thermal stability but slower decomposition rates than typical PEG-based PUs. The stress-strain tests showed that the as-prepared PU co-polymers possessed increased tensile strength and modulus, and decreased toughness in comparison with the blank PEG-based PU. These co-polymers are expected to find specific applications in tissue engineering or controlled drug release.

Why we need semisolid decalcification system in bone tissue engineering? A story begins with honeycomb.

The repair of large segmental bone defects remains a tough problem disturbing surgeons and researchers. Bone tissue engineering brings some new sight in this field. However, it has not been effectively applied in clinics, for the reason that the involved mechanism is not well understood. Thus, we need to know the osteogenesis process of the tissue-engineered bone including distribution, proliferation and interaction among seed cells pre-inoculated in biomaterials as well as the function of surrounding tissues. As a matter of fact, the tissue-engineered bone or the biomaterials are solid and opaque, which makes the study difficult. Here, inspired by the structure of honeycomb and amber, we hypothesize a semisolid decalcification protocol to solve this problem.