Design, Synthesis, and Biomedical Application of Multifunctional Fluorescent Polymer Nanomaterials.

Luminescent polymer nanomaterials not only have the characteristics of various types of luminescent functional materials and a wide range of applications, but also have the characteristics of good biocompatibility and easy functionalization of polymer nanomaterials. They are widely used in biomedical fields such as bioimaging, biosensing, and drug delivery. Designing and constructing new controllable synthesis methods for multifunctional fluorescent polymer nanomaterials with good water solubility and excellent biocompatibility is of great significance. Exploring efficient functionalization methods for luminescent materials is still one of the core issues in the design and development of new fluorescent materials. With this in mind, this review first introduces the structures, properties, and synthetic methods regarding fluorescent polymeric nanomaterials. Then, the functionalization strategies of fluorescent polymer nanomaterials are summarized. In addition, the research progress of multifunctional fluorescent polymer nanomaterials for bioimaging is also discussed. Finally, the synthesis, development, and application fields of fluorescent polymeric nanomaterials, as well as the challenges and opportunities of structure-property correlations, are comprehensively summarized and the corresponding perspectives are well illustrated.

Reconstruction of Anterior Mandible and Mouth Floor Using the Myofascial Iliac Crest Free Flap After Tumor Resection.

The current study introduces a novel approach of anterior mandible and mouth floor reconstruction with the myofascial iliac crest free flap. A series of 4 patients who presented between May 2015 and July 2017 had benefited from this technique. The myofascial component of this flap was designed to be attached to the iliac crest, and the flap was obtained after identifying the neurovascular pedicle. We transferred the iliac crest, with an outward-oriented placement, to the mandibular defect as the base of the alveolar process. We found that the iliac crest can provide sufficient bone height and an aesthetic shape for the reconstruction of the anterior mandible. More important, we also observed that the myofascial component on the flap surface completely replaced the oral mucosa in as early as 1 month after the operation. Moreover, the proper soft tissue volume can be achieved using this approach for better functional reconstruction of the oral mucosa. No obvious scar contracture of the myofascial component was observed during the follow-up period. The myofascial iliac crest free flap could provide a suitable reconstruction method for combined oral mucosa-mandible defects.

Study on the Mechanical Properties and Strengthening Mechanism of Interface-Modified Carbon Fiber Mesh Reinforced Cement-Based Composites with SCA&HMC.

Carbon fiber mesh reinforced cement-based composites (CMCCs) have received extensive attention in the field of engineering repair and structural reinforcement due to their outstanding properties such as two-way force, rust prevention, high specific strength, and low base surface requirements. However, the development of this material has been slowed down to some extent due to the poor interfacial bonding between the carbon fiber mesh and the cement matrix. In this paper, a novel fabrication strategy was proposed in which the carbon fiber mesh was modified with epoxy resin and silane coupling agent (SCA) to increase its surface chemical activity. Meanwhile, the hydroxymethyl cellulose (HMC) was also filled into the concrete matrix to improve the mechanical strength of the matrix as well as the load transfer behaviors between the mortar and carbon fiber (CF) mesh. The potential to employ SCA and HMC was evaluated for the making of CMCCs via the above methods. The results showed that the longitudinal shear strength of composites with SCA and SCA&HMC increased by 26.6% and 56.1% compared to those of CF with epoxy resin (EP) reinforced composites, respectively. The flexural strength of composite with SCA&HMC increases by 147.6% compared to I-(F) without CF. The novel II-HCM&CF/EP-SCA composites with excellent performance are promised to be applied in practical uses.

One-Step Synthesis of Silver Nanoparticles on Polydopamine-Coated Sericin/Polyvinyl Alcohol Composite Films for Potential Antimicrobial Applications.

Silk sericin has great potential as a biomaterial for biomedical applications due to its good hydrophilicity, reactivity, and biodegradability. To develop multifunctional sericin materials for potential antibacterial application, a one-step synthesis method for preparing silver nanoparticles (AgNPs) modified on polydopamine-coated sericin/polyvinyl alcohol (PVA) composite films was developed. Polydopamine (PDA) acted as both metal ion chelating and reducing agent to synthesize AgNPs in situ on the sericin/PVA composite film. Scanning electron microscopy and energy dispersive spectroscopy analysis revealed that polydopamine could effectively facilitate the high-density growth of AgNPs as a 3-D matrix. X-ray diffractometry studies suggested the synthesized AgNPs formed good face-centered cubic crystalline structures. Contact angle measurement and mechanical test indicated AgNPs modified PDA-sericin/PVA composite film had good hydrophilicity and mechanical property. The bacterial growth curve and inhibition zone assays showed the AgNPs modified PDA-sericin/PVA composite film had long-term antibacterial activities. This work develops a new method for the preparation of AgNPs modified PDA-sericin/PVA film with good hydrophilicity, mechanical performance and antibacterial activities for the potential antimicrobial application in biomedicine.

Optimal chin-brow vertical angle for sagittal visual fields in ankylosing spondylitis kyphosis.

PURPOSE: Chin-brow vertical angle (CBVA) is very important in correction of thoracolumbar kyphotic deformity in ankylosing spondylitis (AS), especially for the patients with cervical ankylosis. In previous study, Suk et al. stated that the patients with CBVA between -10° and 10° had better horizontal gaze. Unfortunately, in our clinical practice, we found the patients with CBVA between -10° and 10° after surgery usually complained of difficulty in cooking, cleaning, desk working and the like, although they had excellent horizontal gaze. In other words, for the patients with cervical ankylosis, good horizontal gaze existed together with poor downward gaze. Then, which condition do the patients prefer? Is there a compromise solution that makes a better quality life possible for the patients? In this research, we studied AS patients with cervical ankylosis, aiming to investigate the optimal CBVA for deformity correction. METHODS: 25 AS thoracolumbar kyphotic patients with cervical ankylosis were studied, whose function and expectation of visual field related to life quality were assessed by questionnaire before and after surgery. Pre- and post-operative CBVA were obtained on lateral photos of the patients with free-standing posture, and 50 cases of CBVA were included, which were divided into six groups according to the angle irrespective of surgery (Group A, CBVA <0°; Group B, 0° ≤ CBVA < 10°; Group C, 10° ≤ CBVA < 20°; Group D, 20° ≤ CBVA < 30°; Group E, 30° ≤ CBVA < 40°; Group F, CBVA ≥ 40°). Kruskal-Wallis test was used to assess all the groups in terms of various items in the questionnaire, while Mann-Whitney test was used to assess every two groups. RESULTS: In overall evaluation, Group C (10°-20°) obtained the optimal expectation (p < 0.05); Group B, C and D (0°-30°) obtained better function (p < 0.05), and there was no significant difference between the 3 groups. In appearance, Group A, B and C (<20°) were better than the other groups both in function and expectation (p < 0.05), without dramatic difference among the three groups. In outdoor activities, Group A, B, C and D (<30°) were better in most of the items (p < 0.05). In indoor activities, Group C and D (10-30°) were much better (p < 0.05). CONCLUSION: AS thoracolumbar kyphotic patients with cervical ankylosis had the best satisfaction when 10° ≤ CBVA < 20°.

Magnetic Compression of Polyelectrolyte Microcapsules for Controlled Release.

In this study, microcapsules with a magnetic particle as the core and polyelectrolyte multilayers as the shell were fabricated. The cavity of the microcapsules was created by etching the SiO2 layer, which was first coated on the magnetic core particle, and the size of the cavity can be adjusted by the thickness of the SiO2 layer. This magnetically responsive microcapsule deforms upon application of a constant magnetic field and results in the release of the core content, and the release velocity could be controlled by the strength of the magnetic field. This release mechanism is proactive and repeatable, combined with its localized and remote controllability; it can be a powerful tool for delivering medical agents on site.

New strategy to prepare hollow silica microspheres with tunable holes on the shell wall.

Hollow silica microspheres with holes of tunable numbers and sizes on the shell wall were prepared in this study. Clusters with positively charged polystyrene (PS) microspheres as the central spheres (CSs) and negatively charged PS spheres as the "halo" spheres (HSs) were formed via electrostatic interactions and utilized as a template. In the subsequent silica coating process, only CS was selectively coated; hence, after calcination, porous hollow silica microspheres were obtained.

Layer-by-layer strippable Ag multilayer films fabricated by modular assembly.

We have developed a new method to fabricate multilayer films, which uses prepared thin films as modular blocks and transfer as operation mode to build up multilayer structures. In order to distinguish it from the in situ fabrication manner, this method is called modular assembly in this study. On the basis of such concept, we have fabricated a multilayer film using the silver mirror film as the modular block and poly(lactic acid) as the transfer tool. Due to the special double-layer structure of the silver mirror film, the resulting multilayer film had a well-defined stratified architecture with alternate porous/compact layers. As a consequence of the distinct structure, the interaction between the adjacent layers was so weak that the multilayer film could be layer-by-layer stripped. In addition, the top layer in the film could provide an effective protection on the morphology and surface property of the underlying layers. This suggests that if the surface of the film was deteriorated, the top layer could be peeled off and the freshly exposed surface would still maintain the original function. The successful preparation of the layer-by-layer strippable silver multilayer demonstrates that modular assembly is a feasible and effective method to build up multilayer films capable of creating novel and attractive micro/nanostructures, having great potential in the fabrication of nanodevices and coatings.

Effects of periodontal treatment on glycemic control in type 2 diabetic patients: a meta-analysis of randomized controlled trials.

The association between diabetes and inflammatory periodontal diseases has been studied extensively. However, there is a lack of robustness and homogeneity among studies describing effects of periodontal treatment on glycemic control. The aim of this study was to carry out a meta-analysis to understand whether periodontal treatment could improve glycemic control in type 2 diabetic patients. Electronic searches were carried out on MEDLINE, EMBASE and the Cochrane central register of controlled trials from 1980 to July 2012. Randomized controlled trials of periodontal therapy on glycemic control in diabetic patients with a minimum of 3 months of follow-up were included. Meta-analysis was carried out with 8 studies involving 515 participants using Stata 11.0 software. Our results showed that periodontal treatment could lead to a significant decrease in HbA1c level. The standardized mean difference between intervention groups and control groups was significant: 1.03% (95% confidence interval: 0.31% to 1.70%, P = 0.003) from baseline to 3 months, and 1.18% (95% confidence interval: 0.72% to 1.64%, P < 0.001) from baseline to 6 months. Periodontal treatment could lead to a non-significant decrease in fasting plasma glucose (FPG) levels from baseline to 3 months. The standardized mean difference between the intervention and the control group was 0.69 mg/dl (95% confidence interval: -0.27 mg/dl to 1.66 mg/dl, P = 0.158). Our analysis indicated that periodontal treatment could improve glycemic control in type 2 diabetic patients with periodontal diseases.

Integrated acetic acid and deep eutectic solvent pretreatment on poplar for co-production of xylo-oligosaccharides, fermentable sugars and lignin antioxidants/adsorbents.

Efficient fractionation of lignocellulosic biomass in usable forms of hemicellulose, cellulose and lignin is very important for the sustainable lignocellulosic biorefinery. Herein, poplar sawdust was pretreated with an integrated process composed of acetic acid pre-hydrolysis (170 °C, 60 min) for xylo-oligosaccharides (XOS) production and mild deep eutectic solvent (90-130 °C, 60 min) post-delignification for recovering lignin fractions, resulting in easily hydrolyzed cellulose fraction. Results showed that, after integrated pretreatment and enzymatic hydrolysis, 51 % of xylan and 92 % of glucan in raw biomass could be converted to XOS (DP 2-6) and glucose, respectively, while 71 % of the original lignin could be recovered in DES solvent. The resulting XOS were proven to ensure the growth of probiotics, Bifidobacterium adolescentis. Besides, the lignin macromolecules recovered from DES solvent showed high-purity (around 95 %), low-molecular weight (Mw around 2000), small particle size (270-170 nm) and high-PhOH (3.08 mmol/g) content, which were likely relevant to the excellent antioxidant activity (RSI = 15.16) and adsorbent activity (Pb(II) 461.89 mg/g lignin). Finally, mass balance and energy analysis revealed that the integrated pretreatment could be used as a promising approach for the production of bio-based chemicals and materials from woody biomass.

Modified 1,4-butanediol organosolv pretreatment on hardwoodandsoftwood for efficient coproduction of fermentable sugars and lignin antioxidants.

In this work, 1,4-butanediol (BDO) organosolv pretreatment was modified with different additives for efficient coproduction of fermentable sugars and lignin antioxidants from hardwood poplar and softwood masson pine. It was found additives more greatly improved pretreatment efficacy of softwood than hardwood. 3-hydroxy-2-naphthoic acid (HNA) addition introduced hydrophilic acid groups to lignin structure, while 2-naphthol-7-sulphonate (NS) addition promoted lignin removal, both improving cellulose accessibility for enzymatic hydrolysis. Consequently, BDO pretreatment with 90 mM acid and 2-naphthol-7-sulphonate addition achieved near complete cellulose hydrolysis (97.98%) and maximized sugar yield of 88.23% from masson pine at 2% cellulose and 20 FPU/g enzyme loading. More importantly, the recovered lignin possessed great antioxidant activity (RSI = 2.48), due to increased phenolic OH groups, reduced aliphatic OH groups and molecular weight. Results indicated the modified BDO pretreatment could significantly improve enzymatic saccharification of highly-recalcitrant softwood, while enabling coproduction of high-performance lignin antioxidants for full biomass utilization.

Modified acid pretreatment to alter physicochemical properties of biomass for full cellulose/hemicellulose utilization.

Acid pretreatment of biomass decomposed hemicelluloses but could not effectively remove lignin, which hindered biomass saccharification and carbohydrates utilization. In this work, 2-naphthol-7-sulfonate (NS) and sodium bisulfite (SUL) were simultaneously added to acid pretreatment, which was found to synergistically increase hydrolysis yield of cellulose from 47.9 % to 90.6 %. Based on in-depth investigations, strong linear correlations were observed between cellulose accessibility and lignin removal, fiber swelling, CrI/cellulose ratio, cellulose crystallite size, respectively, indicating that some physicochemical characteristics of cellulose played significant roles in improving cellulose hydrolysis yield. After enzymatic hydrolysis, 84 % carbohydrates could be liberated and recovered as fermentable sugars for subsequent utilization. Mass balance illustrated that for 100 kg raw biomass, 15.1 kg xylonic acid and 20.5 kg ethanol could be co-produced, indicating the efficient utilization of biomass carbohydrates.

Tunable fabrication of two-dimensional arrays of polymer nanobowls for biomimic growth of amorphous calcium carbonate.

Two-dimensional arrays of polymer nanobowls can be fabricated by an oxygen plasma etching technique. The 2D colloidal crystals made of SiO(2) @PMMA particles are fabricated by a convective self-assembly method. The oxygen plasma treatment is applied to the colloidal crystals to selectively etch the PMMA shells. Because the oxygen plasma etching proceeds in a layer-by-layer manner from top to bottom, the top parts of the PMMA shells are etched first, and the silica cores are exposed to the atmosphere, which can be removed with HF, leaving the bowl-shaped PMMA shells to form 2D arrays of polymer nanobowls. The size and packing density of the nanobowl arrays can be tuned with tightly controlled etching time. The polymer nanobowl arrays can also serve as a template to direct the growth of calcium carbonate within the interstice of the nanobowls.

Hofmeister effect on the viscosity properties of gelatin in dilute solutions.

The effect of various Hofmeister anions on the molecular conformation of gelatin in dilute solutions was investigated by viscosity, optical rotation and dynamic light scattering (DLS). The results showed that the intrinsic viscosity of gelatin decreased in the presence of the kosmotropic anions such as Citrate3-, SO42-, H2PO4- and MeCOO-, whereas it was increased with the addition of chaotropes such as Cl- and KSCN-. Furthermore, the intrinsic viscosity of gelatin was directly correlated to the hydration entropy of kosmotropic anions, suggesting that the decrease of the intrinsic viscosity was attributed to the strong hydration effect of kosmotropes. The strong dehydration of gelatin facilitated the folding of the polymer chains into helix bundles, validated by the results of optical rotation. On the contrary, the chaotropic anions could interact directly with polypeptide backbones, and the intrachain hydrogen bonds were destroyed. As a result, the polymer chains expanded, which was confirmed by DLS data, and the intrinsic viscosity was increased. These observations indicate that the molecular conformation of gelatin can be modulated by Hofmeister anions.

Knowledge of Chinese dentists on HPV, their willingness and barriers to recommend HPV vaccination to patients.

Objective: This study aimed to assess the knowledge of Chinese dentists on human papilloma virus (HPV), their willingness and factors prevention them from recommending patients for HPV vaccination, and to identify ways through which dentists can acquire HPV-related knowledge.Methods: This was a cross-sectional study based on Chinese dentists. The anonymous self-filled questionnaire method was used to collect demographic information of participants, their knowledge of HPV, willingness and barriers to recommending HPV vaccines to patients, and the strategies they can adopt to obtain HPV-related knowledge.Results: A total of 517 dentists completed the questionnaire, and 89.94% of dentists were willing to recommend HPV vaccination to patients. Participants aged 30-39 years, male dentists and dentist-in-charge had relatively lower knowledge scores than other groups. Besides, participants aged 30-39 years, working in private hospitals, and practicing in Southern China had a lower willingness to recommend HPV vaccination to patients. Recommending HPV vaccination to patients is not within the scope of practicing dentists, and concerns about the safety of the HPV vaccine were found to be the main barriers preventing its recommendation. Notably, 97.87% of dentists were eager to acquire HPV-related knowledge, and agreed for the first time to enroll in relevant educational courses.Conclusion: Chinese dentists had expressed a strong desire to recommend HPV vaccines to patients, even though their knowledge of HPV was scanty. Therefore, measures to improve their understanding of HPV vaccines and eliminate barriers suppressing their willingness to recommend HPV vaccines are urgently needed.

Structural optimization and finite element analysis of poly-l-lactide acid coronary stent with improved radial strength and acute recoil rate.

Current poly-l-lactide acid (PLLA) scaffolds have issues of inadequate mechanical strength leading to thrombosis formation. Designing a novel bioabsorbable PLLA stent with a novel structure and improved mechanical property is urgently needed. In this study, stent structure modification and optimization based on bioresorbable vascular scaffold Version 1.1 (BVS 1.1, Abbott Laboratories) were conducted. The mechanical property of the redesigned stent was studied using both computerized finite element analysis and experimental mechanical deformation testing, including radial strength (RS), acute recoil (AR), foreshortening (FS), and bending stiffness (BS). The simulated and experimental results showed that the mechanical properties of the modified structure were significantly improved (modified stent vs. BVS 1.1: RS: 2.25 vs. 1.29 N/mm; AR: 3.03 vs. 4.41%; FS: 1.13 vs. 6.89%; BS: 1.49 vs. 0.72 N mm2 ).

Improving enzymatic saccharification of hardwood through lignin modification by carbocation scavengers and the underlying mechanisms.

In this work, the beneficial effect of carbocation scavenger additives on hardwood pretreatment was revealed by significantly improved biomass saccharification: cellulose hydrolysis yield was increased by over 15% after steam pretreatment of poplar, while that was enhanced by more than 48% after dilute acid pretreatment. Besides, the relative contributions of lignin towards enzyme binding and physical barrier effect for proposed mechanisms were quantified. Results indicated that the addition of carbocation scavenger, 2-naphthol-7-sulfonate, resulted in acid groups incorporation of 62.36 mmol/kg to lignin, which mitigated enzyme non-productive binding. Moreover, enlarged biomass porosity and reduced surface lignin coverage were detected through BET and XPS analysis, respectively, which mostly related to the diminished physical barrier effect of lignin. As a result, the lignin inhibitions were significantly suppressed through the addition of carbocation scavenger, giving rise to significantly improved enzymatic hydrolysis of hardwood.

Integrated process for the coproduction of fermentable sugars and lignin adsorbents from hardwood.

This work proposed an integrated process based on alkali-sulfite (AlkSul) pretreatment to coproduce fermentable sugars and lignin adsorbents from hardwood. Different from conventional liquid hot water (LHW) pretreatment, this pretreatment improved cellulose accessibility through selective lignin removal and modification, resulting in significantly enhanced biomass saccharification. Over 75% of the original cellulose and hemicellulose was released and could be recovered as fermentable sugars after pretreatment and subsequent enzymatic hydrolysis. Meanwhile, lignin residues from pretreatment hydrolysate and enzymatic hydrolysate showed lead ions adsorption capacities of 156.25 and 68.49 mg/g, respectively, indicating both streams of lignin residues were favorable adsorbents for heavy metal ions. The improved adsorption capacity of lignin residues was primarily due to the lignin modification as sulfur-containing functional groups incorporation during the integrated pretreatment. Results demonstrated the integrated alkali-sulfite pretreatment improved biomass saccharification, while coproducing lignin adsorbents for wastewater treatment, which can promote the sustainability of lignocellulosic biorefinery.

Two-stage alkali-oxygen pretreatment capable of improving biomass saccharification for bioethanol production and enabling lignin valorization via adsorbents for heavy metal ions under the biorefinery concept.

Converting lignin into value-added products in current lignocellulosic biorefineries has been challenging, which in turn restricts the commercialization of many lignocellulosic biorefineries. In this work, a two-stage alkali-oxygen assisted liquid hot water pretreatment (AlkOx) was proposed as the first step of biorefinery. This alkali-oxygen pretreatment facilitated biomass fractionation by solubilizing majority of lignin in water-soluble fraction, while remaining most of cellulose and hemicellulose in water-insoluble fraction. As a result, biomass saccharification was significantly improved by selective removal and oxidative modification of lignin through alkali-oxygen pretreatment. Moreover, lignin residues from both pretreatment hydrolysate and enzymatic hydrolysate were shown to be favorable adsorbents for Pb(II) ions, with adsorption capacity of 263.16 and 90.91 mg/g, respectively. Results demonstrated that this integrated process could not only improve biomass saccharification but also enable lignin valorization, which encouraged the holistic utilization of lignin residues as part of an integrated biorefinery.