Synthesis of Self-healing and Light-, Thermal-, and Humidity-induced Deformative Polyurethane Actuator.

Intelligent actuating materials have drawn enormous attention because of their potential applications in soft robots, smart sensors, bionics, etc. Aiming to integrate light, thermal, and humidity stimuli deformations and self-healing function into a single polymer, a smart actuating polyurethane material CPPU-50 is designed and successfully synthesized through co-polymerization of azobenzene-containing Azo-C12 , polyethylene glycol 200 (PEG200), and 4,4'-diphenylmethane diisocyanate (MDI) at a ratio of 1:1:2. The obtained polyurethane CPPU-50 exhibits good photoinduced bending, thermal responsive shape memory effect, humidity triggered deflections and self-healing properties. Furthermore, an actuator combining light and thermal stimuli is created and the self-healing CPPU-50 film can withstand the object of 1800 times without tearing. This work can pave a way for further development of long-lived multi-stimuli-responsive actuating devices and intelligent materials.

Preparation of two-component Pickering emulsion hydrogels for the removal of zinc ions from aqueous solutions.

Traditional liquid-solid extraction methods for the removal of zinc ions (Zn(II)) were generally limited by the leakage of extractant and low extraction capacity. The two-component Pickering emulsion hydrogels (PEHGs) in which the synergistic 2-ethylhexyl hydrogen-2-ethylhexylphosphate/tributyl phosphate (EHEHPA/TBP) was encapsulated in a semi-penetrating polymer network (SIPN) structured hydrogels polyacrylamide/sodium alginate (PAM/SA) were prepared by the Pickering emulsions polymerization route. The PEHGs were characterized by FTIR, SEM, TGA, and tensile mechanical measurements, and their self-healing properties were explored. The adsorption performance of PEHGs on Zn(II) was investigated. The results showed that the encapsulation of the extractant reached 95% due to the hydrogels network and nano-silica (nano-SiO2) particle network in PEHGs-15. The critical crashing pressure of PEHGs-15 was 0.084 MPa, and the adsorption after 3 h of healing was only 86% of the original amount. The maximum adsorption capacity of PEHGs-15 on Zn(II) was 76.51 mg/g at pH 5. The functional groups of SA and EHEHPA/TBP enhanced the adsorption capacity of PEHGs-15 by chelating with Zn(II). After five adsorption-desorption cycles, the adsorption capacity of PEHGs-15 exceeded 85% of the initial one. The excellent mechanical properties, self-healing, and regenerative properties of PEHGs-15 offer the potential to remove Zn(II) from the solution.

Lateral flow immunoassay based on gold magnetic nanoparticles for the protein quantitative detection: Prostate-specific antigen.

Point-of-care testing (POCT) demands for rapidly obtaining test results by means of portable analytical instruments and auxiliary reagents at the sampling site. It's important for tumor marker to be recognized and detected in early clinical diagnosis. Many studies focused on producing small portable devices that would allow fast, accurate, and on-site detection. This study aimed to report a magnetic quantitative lateral flow immunoassay (LFIA) system based on poly (acrylic acid) (PAA)-modified gold magnetic nanoparticles (PGMNs) for detecting prostate-specific antigen (PSA) qualitatively and quantitatively. The result was easily achievable with a portable magnetic reader within 15 min. Under optimal conditions, as low as 0.17 ng/mL PSA could be detected. The method was validated using a well-established Solin electrochemiluminescence immunoassay and showed high consistency in detecting 84 serum samples (R2 = 0.98). The quantitative LFIA based on PGMNs established in this study was proven to be rapid, accurate, sensitive, and inexpensive. As a POCT, it can be potentially developed for the quantitative diagnosis of other disease-related protein biomarkers.

Establishment of a Novel Mouse Model for Soft Tissue Expansion.

BACKGROUND: Despite its increasing use, not much is known about tissue expansion, and its complication rates are significantly high. Thus, there is an urgent need to establish a stable animal model to overcome the limitations and complications of tissue expansion. Although the mouse model has shown several advantages in the in-depth studies, an appropriate mouse expansion model has rarely been reported, likely because of its loose skin. MATERIALS AND METHODS: A micro expander was designed and implanted under the scalp of a mouse (expanded group); sterilized saline was regularly injected into the expander. In sham-operated mice (control group), a silicone sheet was implanted under the scalp. Skin samples were collected 5 wk after surgery. Histologic changes including epidermal and dermal thickness and collagen fiber arrangement were analyzed. In addition, vascular density and cell proliferation ratio were determined. An ultrastructural analysis was also performed. RESULTS: With the application of the expansion device, the skin became tight and showed area enlargement. The epidermal thickness of the expanded skin increased significantly (P < 0.01), whereas the thickness of the dermis decreased significantly (P < 0.05) as compared with the control skin. Masson staining demonstrated that collagen bundles were arranged more compactly in the expanded skin (P < 0.05) than in the controls. Furthermore, more proliferating cells (P < 0.05) and blood vessels (P < 0.01) were observed. Transmission electron microscopy showed that the fibers of expanded skin were stretched and broken into bundles of various diameters, with abundant active fibroblasts. CONCLUSIONS: A reliable mouse model of scalp skin expansion was successfully established, which may be a promising tool for in-depth studies on skin soft tissue expansion.

Exosomal microRNA-155-5p from PDLSCs regulated Th17/Treg balance by targeting sirtuin-1 in chronic periodontitis.

The mechanism of local inflammation and systemic injury in chronic periodontitis is complicated, in which and exosomes play an important role. In our study, we found that T helper cell 17 (Th17)/regulatory T cell (Treg) balance is destabilized in the peripheral blood of patients with periodontitis, with upregulated Th17 or downregulated Treg, respectively. Porphyromonas gingivalis lipopolysaccharide (LPS) was used to simulate the inflammatory microenvironment of chronic periodontitis. The exosomes were extracted from periodontal ligament stem cells (PDLSCs) in LPS-induced periodontitis environment, which inversely effected on CD4+ T cells under normal and inflammatory conditions. Furthermore, compared with exosomes from normal PDLSCs, lower expression of microRNA-155-5p (miR-155-5p) and higher expression of Sirtuin-1 (SIRT1) were observed in exosomes from LPS-stimulated PDLSCs. Exosomes from PDLSCs alleviated inflammatory microenvironment through Th17/Treg/miR-155-5p/SIRT1 regulatory network. This study aimed to find the "switching" factors that affected the further deterioration of periodontitis to maximally control the multiple downstream damage signal factors to further understand periodontitis and find new targets for its treatment.

Periodontal disease in Chinese patients with rheumatoid arthritis: A case-control study.

OBJECTIVE: To evaluate the prevalence and severity of periodontal disease in Chinese rheumatoid arthritis patients. SUBJECTS AND METHODS: This cross-sectional study included 128 RA and 109 healthy controls. Two dentists conducted periodontal status including Plaque index (PI), Gingival index (GI), pocket probing depths (PPDs), Clinical attachment level (CAL) and Bleeding on probing (BOP) independently. Sociodemographic, lifestyle, clinical parameters and use of medication were assessed. Data were analyzed by Student's t test, χ2 test, Wilcoxin-Mann- Whitney's test, Correlational Analysis, univariate or multivariate logistic regression. RESULTS: The periodontal status was significantly worse in RA, especially the condition of dental and gingival status. RA had 4.68-fold. After adjusted potential risk factors, RA had 10.26-fold. The independent variable related to GI was DAS28 (p = .05) negatively, to the contrary, ESR (p = .013) was positively associated; the independent variable positively and related to periodontitis was educational level (p = .021) and anti-CCP positivity (p = .002). Through multivariate logistic regression, age and swollen joint were the independent variable related to periodontitis of RA (OR 1.087, p = .044) and (OR 1.560, p = .008) respectively. CONCLUSIONS: Chinese RA patients show higher odds of PD. It is important to take early interventions in combination with medical therapy.

Multiphoton microscopy imaging of developing tooth germs.

BACKGROUND/PURPOSE: Traditionally, tooth germ is observed by histological investigation with hematoxylin and eosin stain and information may loss during the process. The purpose of this study is to use multiphoton laser fluorescence microscopy to observe the developing tooth germs of mice for building up the database of the images of tooth germs and compare with those from conventional histological analysis. METHODS: Tooth germs were isolated from embryonic and newborn mice with age of Embryonic Day 14.5 and Postnatal Days 1, 3, 5, and 7. RESULTS: Comparison of the images of tooth germ sections in multiphoton microscopy with the images of histology was performed for investigating the molar tooth germs. It was found that various signals arose from different structures of tooth germs. Pre-dentin and dentin have strong second-harmonic generation signals, while ameloblasts and enamel tissues were shown with strong autofluorescence signals. CONCLUSION: In this study, a novel multiphoton microscopy database of images from developing tooth germs in mice was set up. We confirmed that multiphoton laser microscopy is a powerful tool for investigating the development of tooth germ and is worthy for further application in the study of tooth regeneration.

Overexpression of tocopherol biosynthesis genes in guayule (Parthenium argentatum) reduces rubber, resin and argentatins content in stem and leaf tissues.

Natural rubber produced in stems of the guayule plant (Parthenium argentatum) is susceptible to post-harvest degradation from microbial or thermo-oxidative processes, especially once stems are chipped. As a result, the time from harvest to extraction must be minimized to recover high quality rubber, especially in warm summer months. Tocopherols are natural antioxidants produced in plants through the shikimate and methyl-erythtiol-4-phosphate (MEP) pathways. We hypothesized that increased in vivo guayule tocopherol content might protect rubber from post-harvest degradation, and/or allow reduced use of chemical antioxidants during the extraction process. With the objective of enhancing tocopherol content in guayule, we overexpressed four Arabidopsis thaliana tocopherol pathway genes in AZ-2 guayule via Agrobacterium-mediated transformation. Tocopherol content was increased in leaf and stem tissues of most transgenic lines, and some improvement in thermo-oxidative stability was observed. Overexpression of the four tocopherol biosynthesis enzymes, however, altered other isoprenoid pathways resulting in reduced rubber, resin and argentatins content in guayule stems. The latter molecules are mainly synthesized from precursors derived from the mevalonate (MVA) pathway. Our results suggest the existence of crosstalk between the MEP and MVA pathways in guayule and the possibility that carbon metabolism through the MEP pathway impacts rubber biosynthesis.

Montelukast Attenuates Retraction of Expanded Flap by Inhibiting Capsule Formation around Silicone Expander through TGF-ß1 Signaling.

BACKGROUND: Tissue expansion has tremendous applications in plastic surgery, but flap retraction provides insufficient tissue for use. Inspired by the use of montelukast to suppress capsular contracture, the authors investigated the effects of montelukast on capsule formation around the expander and retraction of the expanded scalp of the rat. METHODS: Thirty-six male Sprague-Dawley rats were randomly divided into control and montelukast groups. In each group, 12 expanded flaps with or without capsules were harvested for histologic and molecular analysis; the six remaining expanded flaps were transferred to repair defects. Myofibroblast and transforming growth factor-ß1 expression in the capsule was determined using immunofluorescence. Capsule ultrastructure was observed using transmission electron microscopy. Related protein expression in the capsules was detected using Western blot analysis. RESULTS: A comparison of control and montelukast groups revealed that areas of the harvested expanded flaps with capsules were greater (2.04 ± 0.11 cm 2 versus 2.42 ± 0.12 cm 2 , respectively; P = 0.04); the retraction rate decreased (41.3% ± 2.16% versus 28.13% ± 2.17%, respectively; P < 0.01). However, the increased areas and decreased retraction disappeared after capsule removal. The number of myofibroblasts declined. Thin, sparse collagen fibers were observed in the capsules. The expression of COL1, COL3, TGF-ß1, EGR1, and phosphorylated ERK1/2 in the capsules decreased. Furthermore, the recipient area repaired by the transferred expanded flap was increased from 4.25 ± 0.39 cm 2 to 6.58 ± 0.31 cm 2 ( P < 0.01). CONCLUSION: Montelukast attenuates retraction of the expanded flap by inhibiting capsule formation through suppressing transforming growth factor-ß1 signaling. CLINICAL RELEVANCE STATEMENT: This study provides novel insights into a method for increasing the area of the expanded flap.

Diagnosis of hand, foot, and mouth disease caused by EV71 and other enteroviruses by a one-step, single tube, duplex RT-PCR.

Hand, foot, and mouth disease (HFMD) is caused mainly by enterovirus 71 (EV71) and other enteroviruses (EVs) such as Coxsackie A16 in China. EV71 infection can lead to severe clinical manifestations and even death. Other EVs, however, generally cause mild symptoms. Thus, early and accurate distinction of EV71 from other EVs for HFMD will offer significant benefits. A one-step, single tube, duplex RT-PCR assay is described in the present study to detect simultaneously EV71 and other EVs. The primers used for the duplex RT-PCR underwent screening and optimization. The detection threshold was 0.001 TCID(50)/ml for EV71 and 0.01 TCID(50)/ml for other EVs. The positive rate of enterovirus detection in 165 clinical samples reached 68.5%, including 46.1% for EV71 and 22.4% for other EVs. Of all the severe HFMD cases, EV71 was responsible for 85.3% cases. The positive rate of EV71 fell markedly by day 8 after onset. In addition, sequencing of EV71 specific amplicons from duplex RT-PCR revealed that C4a was the predominant subgenotype of EV71 circulating in Nanjing, China. The accuracy and reliability of the assay suggest strongly that the one-step, single tube, duplex RT-PCR will be useful for early diagnosis and monitoring of EV71 and other EV infections.

Effects of Long-Term Enclosed Environment on Human Health Based on the Analysis of Salivary Microbiota and Cytokines.

The long-term exposure to enclosed environments may lead to chronic stress in crewmembers and affect their physical and mental state. Salivary microbiome and biomarkers of immune function are increasingly used in human health research. The "Lunar Palace 365" project, which was a 370-day, multicrew, enclosed experiment carried out in a ground-based bioregenerative life support system platform named Lunar Palace 1 (LP1). We investigated the temporal dynamics of the salivary microbiota and cytokines in the third phase of the "Lunar Palace 365" experiment, including 1 month before entering LP1 and 1 month after leaving Lp1. Results reveal no regular temporal change pattern in these parameters (highly abundant phyla and genera) during the experiment. Although the crewmembers' oral microbiota temporally changed, it recovered quickly after the study subjects left the enclosed environment. The levels of IL-6, IL-10, and TNF-α in crewmembers' saliva decreased after leaving the normal environment for the enclosed environment, indicating that their oral inflammatory response level was reduced. There were significant individual differences in crewmembers' salivary microbiota, however, the shared living space reduced these differences. Moreover, air microbiota might have also played a significant role in reducing the individual differences. In summary, the enclosed environment did not result in persistent changes in human salivary microbiota and oral immunity. This study provides some insights for studying the effect of enclosed controlled environments on human immunity and microbiome. IMPORTANCE Long-term exposure to space environments may influence the human microbiome, the human immune system, and the intricate balance between the two, causing impaired immunity and increased disease susceptibility. It was previously believed that the main potential factors of long-term spaceflight on human health were microgravity and radiation. However, the effects of long-term enclosed environments on human health were unclear. Bioregenerative life support systems (BLSS) is a good experimental model for studying the effects of enclosed environments on human systemic microbiota and immune disorders. We monitored the microbiota and cytokines in the saliva of crewmembers before they entered BLSS, during their stay in BLSS, and after leaving BLSS. The results indicated long-term closed environment will not cause persistent changes in human salivary microbiota and immunity.

Fabrication of gold nanorods-doped, bovine serum albumin microstructures via multiphoton excited photochemistry.

In this study, three-dimensional (3D) crosslinked bovine serum albumin (BSA) microstructures containing gold nanorods (AuNRs) were fabricated via multiphoton excited photochemistry using Rose Bengal (RB) as the photoactivator. To retain AuNRs in the 3D crosslinked BSA microstructures, the laser wavelength was chosen for two-photon RB absorption for improved two-photon crosslinking efficiency, but not for enhancing the longitudinal plasmon resonance of AuNRs which may result in photothermal damage of AuNRs. Furthermore, with two-photon excitation of RB via AuNRs plasmonics, the laser power can be reduced by about 30%. As a result, 3D BSA microstructures containing AuNRs can be successfully fabricated. The AuNRs-doped BSA microstructures can be applied in biomedical scaffolds with plasmonic properties such as two-photon luminescence imaging and photothermal therapy.

RNASeq analysis of drought-stressed guayule reveals the role of gene transcription for modulating rubber, resin, and carbohydrate synthesis.

The drought-adapted shrub guayule (Parthenium argentatum) produces rubber, a natural product of major commercial importance, and two co-products with potential industrial use: terpene resin and the carbohydrate fructan. The rubber content of guayule plants subjected to water stress is higher compared to that of well-irrigated plants, a fact consistently reported in guayule field evaluations. To better understand how drought influences rubber biosynthesis at the molecular level, a comprehensive transcriptome database was built from drought-stressed guayule stem tissues using de novo RNA-seq and genome-guided assembly, followed by annotation and expression analysis. Despite having higher rubber content, most rubber biosynthesis related genes were down-regulated in drought-stressed guayule, compared to well-irrigated plants, suggesting post-transcriptional effects may regulate drought-induced rubber accumulation. On the other hand, terpene resin biosynthesis genes were unevenly affected by water stress, implying unique environmental influences over transcriptional control of different terpene compounds or classes. Finally, drought induced expression of fructan catabolism genes in guayule and significantly suppressed these fructan biosynthesis genes. It appears then, that in guayule cultivation, irrigation levels might be calibrated in such a regime to enable tunable accumulation of rubber, resin and fructan.

Multiphoton fabrication of freeform polymer microstructures with gold nanorods.

In this study, three-dimensional (3D) polyacrylamide microstructures containing gold nanorods (AuNRs) were fabricated by two-photon polymerization (TPP) using Rose Bengal (RB) as the photoinitiator. To retain AuNRs in the 3D polymer microstructures, the laser wavelength was chosen for two-photon RB absorption for improved TPP efficiency, but not for enhancing the longitudinal plasmon resonance of AuNRs which may result in photothermal damage of AuNRs. After TPP processing, the laser wavelength was tuned for the longitudinal plasmon resonance and the laser power was increased to beyond the damage threshold of the AuNRs for reshaping the AuNRs into gold nanospheres. As a result, AuNRs in designated positions of the fabricated 3D microstructures can be achieved. Two-photon luminescence from the doped AuNRs can also act as contrast agent for the visualization of 3D polymer microstructures.

Characterizing phase-separated microstructure of polymeric blended membrane using combined multiphoton and reflected confocal imaging.

In this study, we propose a novel, minimally-invasive multimodal optical imaging method which combines multiphoton and reflected confocal microscopy for characterizing three-dimensional phase-separated microstructure of polymeric nylon/chitosan blends. The multimodal image acquisition was performed on a Zeiss LSM 510 inverted microscope system using a ti-sapphire laser source. Differences in nonlinear optical signals between individual homopolymers were used to characterize the phase-separation phenomenon within the polymeric blends. We also used the reflected confocal signals for defining the interfacial boundaries of different refractive indices. Our work demonstrates that the proposed multimodal imaging modality can be used to provide the necessary microstructural information for characterizing the degrees of phase separation within polymeric blends.

Prevalence, severity, and predictors of dry eye and dry mouth in Chinese patients with primary Sjögren syndrome.

Dry eye and dry mouth are typical clinical symptoms of primary Sjögren's syndrome (pSS), yet not considered in the assessment of severity and predictors in China. This study aimed to investigate the prevalence, severity, and potential predictors of dry eye/dry mouth among Chinese pSS patients. A cross-sectional study was conducted from the Affiliated Hospital of Nantong University. A series of questionnaires were applied: Ocular Surface Disease Index (OSDI), EULAR Sjogren's Syndrome Patient Reported Index (ESSPRI)-dry mouth items, fatigue severity scale (FSS), the 10 cm visual analog scale (VAS). Laboratory examinations were taken to obtain some biochemical indicators (i.e., C-reactive protein, erythrocyte sedimentation rate, anti-SSA/SSB antibody). Stepwise logistic/linear regression model was used to investigate the potential predictors of dry eye/dry mouth, respectively. Statistical analysis was performed using SPSS version 20.0. Two hundred twenty-four pSS patients were included in this study. Among them, 215 (95.98%) patients reported ESSPRI-dry mouth items score > 0, and the mean score was 4.92 ± 2.43. In addition, according to the score of OSDI, 84 (37.5%) subjects reported non-dry eye, whereas 140 (62.5%) subjects reported dry eye (44 mild, 31 moderate, 65 severe), and the mean of the total OSDI score was 25.01 ± 23.58. Then, using logistic regression and linear regression respectively, we found that age and fatigue were the potential predictors of dry eye, whereas dry mouth was predicted by age, fatigue, total pain, and ESR. The results of this study suggested that rheumatologists should pay attention to pSS patients' dry eye and dry mouth, especially those with older age, higher level of ESR, more severe fatigue, and pain.

Ultrasonic polymerization of CuO@PNIPAM and its temperature tuning glucose sensing behavior.

The extraordinary high pressure and temperature produced during cavitation is crucial for ultrasonic sonochemistry. However, the cavitation effect is usually confined to a small zone nearby the ultrasonic horn, outside of which ultrasound produces much less effects on chemical reaction. In present work, in order to expand the range of effective zone and intensify the cavitation effect, N2 aeration was introduced to an ultrasonic polymerization process of CuO@PNIPAM in aqueous solution. By increasing the number of bubble nucleus gathered on the CuO surface and lowering the surface tension of the aqueous solution, the cavitation effect is intensified on the CuO surface within the whole reaction vessel, which benefits the covalently bonding between PNIPAM and CuO to a large degree and results in the formation of CuO@PNIPAM hybrid composite with excellent interfacial bonding. It is promising that the hybrid composite can be applied as temperature responsive glucose sensing platform with ON and OFF states due to the wettability change of PNIPAM versus temperature.

Multiphoton autofluorescence and second-harmonic generation imaging of the tooth.

In this study, we used an epi-illuminated multiphoton microscope to image three main components of ex vivo human tooth. In particular, we obtained two-photon excited autofluorescence (AF) and second-harmonic generation (SHG) images of the enamel, dentin, and periodontal ligaments (PLs) and constructed three-dimensional projections of sequentially and axially acquired images. We found that the enamel has a strong two-photon AF signal, clearly revealing the structures of the enamel rods. The dentin, on the other hand, has both AF and SHG signals. The contrast provided by the combination of these two imaging modalities can be used to reveal the structure of peritubular dentin and to distinguish the less mineralized circumpulpal dentins. The SHG and multiphoton AF imaging also showed the structure of the PL and the distribution of cells around the PL, respectively. For comparison, we also obtained scanning electron microscopy images of the enamel, dentin, circumpulpal dentin, and the PL. Our results demonstrate the effectiveness of using multiphoton microscopy to visualize the major constituents of teeth, including enamel, dentin, and the PL, and the potential of this minimally invasive technique for monitoring the morphological developments during tooth regeneration.

[Comparison of mechanical properties on different phase transformation points of nickel-titanium orthodontic wires].

OBJECTIVE: To compare the mechanical properties of different phase transformation of nickel-titanium orthodontic archwires. METHODS: Nickel-titanium orthodontic archwires with same-sized (0.016") but different phase transformation were examined using a three-point bend test. Samples were tested at same conditions and oral temperature(37 degree), but in different utmost strain capacity, then the strain-stress chart was obtained, the phase transformation point (Af) was also examined. RESULT: The wires of the highest phase transformation point had the least orthodontic force; on the contrast the least phase transformation point had the highest orthodontic force at 3.0 mm utmost strain capacity. The orthodontic forces were not different at the little strain capacity (P >0.05), but which was significantly different adove the 0.5 mm (P<0.05), which was same as 3.0 mm. CONCLUSION: The nickel-titanium orthodontic archwires with high level of phase transformation have low orthodontic forces and more stability.

Imaging human bone marrow stem cell morphogenesis in polyglycolic acid scaffold by multiphoton microscopy.

The noninvasive imaging of tissue engineering constructs is vital for understanding the physiological changes in construct formation and the design of improved products for therapeutic purposes. In this work, we use the combination of multiphoton autofluorescence and second harmonic generation (SHG) microscopy to image the physiological changes to the engineered constructs of human mesenchymal stem cells seeded in a polyglycolic acid (PGA) scaffold under induction by chondrogenic transforming growth factor-beta3. Without histological procedures, we found that multiphoton autofluorescence is useful for imaging the PGA scaffold and stem cells while SHG is useful for following the progress of extracellular matrix (ECM) formation. We found that the initial ECM formation tends to align along the PGA scaffold orientation and progressive induction alters the scaffold conformation, indicating that biomechanical forces or the chemical environment generated by chondrogenesis is sufficient for scaffold reorganization. Our results suggest that in the future this approach may be used for real-time monitoring of the physiological processes associated with tissue engineering.