DNA liquid crystals with AIE effect toward humidity-indicating biomaterials.

In this study, by fabricating DNA doped with tetraphenylethene-containing ammonium surfactant, the resulting solvent-free DNA ionic complex could undergo a humidity-induced phase change that could be well tracked by the fluorescence signal of the surfactant. Taking advantage of the humidity-induced change in fluorescence, the reported ionic DNA complex could accurately indicate the humidity in real time.

Ultra-high-performance liquid chromatography with tandem mass spectrometry method for cellular toxicity and pharmacokinetic study of PEG1K polymers.

Polyethylene glycol (PEG) is one of the most commonly used polymers in drug delivery systems. The investigation of the pharmacokinetic behavior of PEG is important for revealing the toxicity and efficiency of PEG-related Nano-drug delivery systems. A high through-put and selective ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method coupled with collision-induced dissociation (CID) in source technique was developed and validated to determine PEG1K polymers in cellular samples in this study. The countless precursor ions of PEG1K are dissociated in the source to generate numerous product ions which have different numbers of subunits. The transition of [M+H]+ precursor ions → product ions at m/z 177.1 (four subunits)→89.1 (two subunits) was selected to determine PEG1K due to its high sensitivity. The UHPLC-MS/MS method coupled with CID in the source showed good linearity over the range of 0.1-10 µg/mL. Intra-day and inter-day accuracies and precisions of the assay were all within ± 12.39%. The assay was successfully applied to a cellular pharmacokinetic study of PEG1K in human breast cancer cells. The cytotoxicity of PEG1K polymers was also studied and the results indicated that the cytotoxicity of PEG1K was not significant in the range of 5-1200 µg/mL.

Association between serum neurofilament light chain and periodontitis.

OBJECTIVES: The association between serum neurofilament light chain (sNfL) and periodontitis remains unclear, and there is a need to examine the contribution of serum albumin (SA) in this association. The objective of the study is to investigate the correlation between sNfLand periodontitis, while examining the potential mediator role of SA in this association. METHODS: The study, which included 1218 participants from the 2013-2014 National Health and Nutrition Examination Survey (NHANES), aimed to evaluate the association between sNfL and periodontitis through weighted multivariable logistic regression analysis, restricted cubic spline (RCS) models, and stratified models. In addition, mediation analysis was used to investigate the role of SA in mediating this association. RESULTS: The multivariable logistic regression models revealed that sNfL was significantly linked to periodontitis (model 1: odds ratio [OR], 3.08, 95% confidence interval [CI], 1.48 to 6.39, model 2: OR, 3.69; 95% CI, 1.73 to 7.90, model 3: OR, 3.58, 95% CI, 1.52 to 8.43). The RCS models suggested a linear relationship between sNfL and periodontitis. The stratified analysis revealed no significant moderating effects (p-value > 0.05). The mediation analysis demonstrated that SA mediated the correlation between sNfL and periodontitis, with a mediation proportion of 10.62%. CONCLUSIONS: The results point to sNfL being a factor in the heightened risk of periodontitis. Additionally, SA may mediate the changes in periodontitis that are associated with sNfL. CLINICAL RELEVANCE: sNfL may contribute to the development of periodontitis by mediating changes in SA in humans.

Restoration of teeth lacking complete ferrules using cast precious metal alloy post-and-cores and knife-edged crowns: A retrospective clinical study.

STATEMENT OF PROBLEM: While the presence of a ferrule has been reported to be essential for post-and-core restorations, many extensively damaged teeth lack complete ferrules. The outcome of post-and-core restorations for these teeth remains uncertain. PURPOSE: The purpose of this retrospective clinical study was to assess the outcome of cast alloy post-and-cores and knife-edged crowns for the restoration of teeth lacking complete ferrules. MATERIAL AND METHODS: A total of 106 participants with endodontically treated teeth with 2 or fewer walls with ferrules who had received cast precious metal alloy post-and-cores along with knife-edged crowns between 2013 and 2022 were recalled for a clinical examination. The minimum follow-up time was 5 months after restoration, and restoration failure and the periodontal status difference between restored teeth and reference teeth were determined. Kaplan-Meier analysis was performed to obtain success curves. The influence of age, sex, jaw position, tooth type, and antagonistic dentition upon the success function was analyzed with the log-rank or Breslow test (α=.05). RESULTS: A total of 100 participants with 130 restorations were studied. The success rate of the restorations was 93.85% in a mean ±standard deviation period of 48.3 ±26.1 months. The estimated 5-year cumulative success probability was 91.61%. No significant effect on the success of restorations was found regarding age, sex, jaw position, tooth type, or antagonistic dentition (P>.05). The main failure types were post debonding, root fracture, and apical periodontitis. No statistical difference in tooth mobility (Z=-1.265, P=.206) was found between the restored and the reference teeth, but the plaque index and calculus index of the restored teeth were significantly lower than of the reference teeth (Z=-7.216, P<.001; Z=-7.044, P<.001). Teeth that had received cast post-and-cores and knife-edged crowns were found to have no significant correlation with periodontal disease (χ²=1.131, P=.288) or bleeding on probing (χ²=3.436, P=.064). CONCLUSIONS: The clinical outcomes for the restoration of teeth with 2 or fewer walls with ferrules using cast precious metal alloy post-and-cores and knife-edged crowns were favorable, exhibiting a high 5-year cumulative success probability and no increased periodontal health risk.

Clinical evaluation of closed tray impression and intraoral scanning techniques in single posterior tissue-level implant-supported crowns: A self-controlled case study.

STATEMENT OF PROBLEM: Different techniques have been used to record the locations of dental implants, yet research examining the clinical outcomes of posterior implant-supported prostheses generated by different techniques, particularly concerning their fit, is lacking. PURPOSE: The purpose of this self-controlled study was to evaluate the clinical outcomes of closed tray impression making and intraoral scanning for single posterior implant-supported restorations. MATERIAL AND METHODS: Eighty-two participants with a single missing posterior tooth were included. The restorations were delivered a minimum of 3 months after tissue-level implant placement. Each participant was provided with 2 screw-retained monolithic zirconia crowns, produced using 3-dimensional (3D) gel deposition from both closed tray impression making (control group) and intraoral scanning using an iTero scanner (experimental group). The recording operating time, the patient comfort assessed using a visual analog scale (VAS), and the fit of the crowns were recorded during clinical evaluation. The paired t test and Mann-Whitney U test were conducted to statistically analyze the differences between the 2 techniques (α=.05). RESULTS: Seventy-six participants completed the study with a dropout rate of 7.3%. The mean ±standard deviation recording operating time of the control and experimental groups was 683 ±164 and 777 ±407 s, respectively (P<.05). The mean ±standard deviation VAS score of the control and experimental groups was 2.6 ±1.6 and 1.3 ±1.0, respectively (P<.05). The crowns in both groups showed excellent marginal fit (P>.05), but the occlusal contacts of crowns in the experimental group were significantly better (P<.05), while the interproximal contacts were significantly worse (P<.05) compared with those in the control group. In the control group, 1 crown was rated as Delta for occlusal contact and deemed clinically unacceptable. CONCLUSIONS: In single posterior tissue-level implant-supported restorations, the clinical outcomes of most of the screw-retained monolithic zirconia crowns generated from closed tray impression making and intraoral scanning with the iTero system and fabricated by 3D gel deposition were acceptable. Compared with the closed tray impression technique, intraoral scanning resulted in better patient comfort and occlusal contacts but worse interproximal contacts. Efficiency was lower with intraoral scanning.

Clinical outcomes of self-glazed zirconia veneers produced by 3D gel deposition: a retrospective study.

BACKGROUND: Self-glazed zirconia (SZ) restorations are made by a novel additive three-dimensional gel deposition approach, which are suitable for a straightforward completely digital workflow. SZ has recently been used as minimally invasive veneer, but its clinical outcomes have not been clarified yet. This study aimed to evaluate the preliminary clinical outcomes of SZ veneers compared with the widely used lithium disilicate glass-ceramic veneers made by either pressing (PG) or milling (MG) process. METHODS: Fifty-six patients treated with SZ, PG, and MG veneers by 2 specialists between June 2018 and October 2022 were identified. Patients were recalled for follow-up at least 1 year after restoration. Clinical outcomes were assessed by 2 independent evaluators according to the modified United States Public Health Service (USPHS) criteria. Overall patient satisfaction was assessed using visual analogue scale (VAS), and analyzed by one-way ANOVA. Chi-square test was applied to compare the difference in the success and survival rates among the 3 groups. RESULTS: A total of 51 patients restored with 45 SZ, 40 PG, and 41 MG veneers completed the study, with a patient dropout rate of 8.9%. Mean and standard deviation of follow-up period was 35.0 ± 14.7 months. All restorations performed well at baseline, except for 2 SZ veneers with mismatched color (rated Bravo). During follow-up, marginal discrepancy (rated Bravo) was found in 4 MG veneers and 1 PG veneer, and partially fractured (rated Charlie) was found in another 2 PG veneers. The survival rate of SZ, PG, and MG veneers was 100%, 95%, and 100%, with a success rate of 95.56%, 92.50%, and 90.24%, respectively, none of which were significantly different (p = 0.099 and 0.628, respectively). The mean VAS score of SZ, PG, and MG was 95.00 ± 1.57, 93.93 ± 2.40, and 94.89 ± 2.00 respectively, without significant difference (p > 0.05). CONCLUSION: SZ veneers exhibited comparable preliminary clinical outcomes to PG and MG veneers, which could be considered as a feasible option for minimally invasive restorative treatment.

Turnover behavior and intention among dentists and medical doctors: a cross-sectional study in China.

BACKGROUND: Retention of doctors is a global challenge and doctors working in different departments may face different problems. The study aimed to explore the turnover behavior and intention and correlated factors among Chinese dentists and medical doctors in other clinical fields. METHODS: A cross-sectional study was conducted online in 5 regions of China from March 12th to April 12th, 2020. The questionnaire included 3 parts, socio-demographic characteristics, turnover behavior and intention, and concerns about work-related factors. Chi-square test and/or Wilcoxon Mann-Whitney test were applied for comparison, and binary logistic regression was used for finding the factors. RESULTS: A total of 2428 eligible questionnaire were received, comprising 1954 responses from dentists and 474 from medical doctors. Rates of turnover behavior among dentists and medical doctors were 2.87% and 6.96%, respectively. Similarly, rates of turnover intention were 51.79% among dentists and 71.20% among medical doctors. Educational level was negatively correlated with turnover behavior of both medical doctors and dentists, and concern about salary was a unique negatively correlated factor for dentists. Age was negatively correlated with turnover intention in both medical doctors and dentists. Conversely, concerns about workload and doctor-patient relationship were positively correlated with turnover intention in both groups. Concern about salary was the distinct correlated factor of medical doctors' turnover intention, while gender and annual household income were correlated with turnover intention among dentists. CONCLUSIONS: Low turnover rate but high turnover intention rate was the current status of Chinese doctors' employment. Turnover behavior and intention were more optimistic among dentists than medical doctors. Factors related to turnover behavior and turnover intention were not identical among dentists and medical doctors. Therefore, personalized retention measures were necessary for dentists and medical doctors.

Effect of a Permanganate-Bearing Reactive Oxidant on Flocs in Electrocoagulation: Transformations and Interfacial Interactions.

The electrocoagulation/ultrafiltration (ECUF) process is expected to address the issues of current wastewater increments and complex water reuse. However, the underlying mechanism associated with flocs remains unclear in the ECUF system, especially in the upgraded permanganate-bearing ECUF (PECUF) system. Herein, flocs and their formation, response to organic matter (OM), and interfacial features in the PECUF process were systematically explored. Results demonstrated that permanganate contributed to the rapid start-up of the coagulation process by forming MnO2 and blocking the ligand-metal charge transfer process between adsorbed Fe(II) and solid-phase Fe(III). The response of flocs to natural OM (NOM) exhibited obvious time- and particle size-dependent characteristics. Based on this, the optimal NOM adsorption window was found to be in the interval of 5-20 min, whereas the optimal NOM removal window was located at the 20-30 min interval. Furthermore, the extended Derjaguin-Landau-Verwey-Overbeek theory revealed the underlying principle of the PECUF module for optimizing UF performance. On the one hand, it reduced the inherent resistance of the cake layer by modifying the colloidal solution, which guaranteed a small drop (15%) in initial flux. On the other hand, it enhanced the repulsive force among suspended particles to achieve a long-term antifouling effect. This study may provide insights into the selection and performance control of on-demand assembly modules in decentralized water treatment systems.

Disposable Polypropylene Face Masks: A Potential Source of Micro/Nanoparticles and Organic Contaminates in Humans.

We have been effectively protected by disposable propylene face masks during the COVID-19 pandemic; however, they may pose health risks due to the release of fine particles and chemicals. We measured micro/nanoparticles and organic chemicals in disposable medical masks, surgical masks, and (K)N95 respirators. In the breathing-simulation experiment, no notable differences were found in the total number of particles among mask types or between breathing intensities. However, when considering subranges, <2.5 µm particles accounted for ∼90% of the total number of micro/nanoparticles. GC-HRMS-based suspect screening tentatively revealed 79 (semi)volatile organic compounds in masks, with 18 being detected in ≥80% of samples and 44 in ≤20% of samples. Three synthetic phenolic antioxidants were quantified, and AO168 reached a median concentration of 2968 ng/g. By screening particles collected from bulk mask fabrics, we detected 18 chemicals, including four commonly detected in masks, suggesting chemical partition between the particles and the fabric fibers and chemical exposure via particle inhalation. These particles and chemicals are believed to originate from raw materials, intentionally and nonintentionally added substances in mask production, and their transformation products. This study highlights the need to study the long-term health risks associated with mask wearing and raises concerns over mask quality control.

Flavonoids dimers from the fruits of Psoralea corylifolia and their cytotoxicity against MCF-7 cells.

Nine new flavonoids dimers, psocorylins R-Z (1-9), were isolated from the fruits of Psoralea corylifolia L. (Psoraleae Fructus), a traditional Chinese medicine. The structures of these compounds were elucidated via multiple spectroscopic techniques and X-ray diffraction. Psocorylins R (1) and S (2) were rare cyclobutane-containing chalcone dimers, and psocorylins T-Z (3-9) were established by CC or COC bond of two flavonoid monomers. The structural-types, flavonoids dimers, were isolated from the plant for the first time, enriching the chemical diversity. The cytotoxicity assay suggested that compounds 1, 2, 4, 5, 6 and 8 exhibited cytotoxic activities against MCF-7 cells. Furthermore, compounds 1 and 8 significantly increased intracellular ROS levels, decreased MMP and induced apoptosis of MCF-7 cells. They markedly upregulated the expression of Bax and cleaved caspase-3, and suppressed Bcl-2 and caspase-3 levels, indicating their mechanism of Bcl-2/Bax/Cleaved caspase-3 pathway. Hence, our findings not only promoted the chemical investigation of Psoraleae Fructus, but also provided potential bioactive natural products for anti-cancer.

Abnormal tooth maturation associated with port wine stains.

OBJECTIVE: This study aims to evaluate the potential impact of port wine stains on the development of permanent teeth in mixed dentition and provide insights for managing tooth abnormalities in patients with port wine stains. MATERIALS AND METHODS: A retrospective analysis was conducted on 21 patients with mixed dentition and unilateral maxillary port wine stains. Two researchers concurrently utilized Nolla Analysis to assess the developmental stage of bilateral maxillary and permanent mandibular teeth based on panoramic radiographs. The cumulative developmental values of upper and lower permanent teeth on both sides were calculated, and a comparison was made between the developmental stages of the upper and lower jaws. RESULTS: Port wine stains can influence the maturity of permanent upper teeth, within the unilateral maxillary port wine stains range, with an early developmental completion observed on the affected side compared to the unaffected side. While the developmental stages of the lower teeth on both sides showed similarities. CONCLUSIONS: Port wine stains can accelerate the maturity of teeth on the affected side, leading to alterations in the order of tooth eruption and subsequent abnormal occlusion in children with mixed dentition. These findings provide a basis for developing appropriate management strategies for addressing tooth abnormalities in patients with port wine stains.

Skin pigmentation improvement with resveratrol microemulsion gel using polyoxyethylene hydrogenated castor oil.

OBJECTIVE: To investigate the safety and efficacy of resveratrol microemulsion gel in improving pigmentation. METHODS: Resveratrol microemulsion gel was prepared by the microemulsion solubilization method, and its quality was evaluated. The transdermal and drug retention rates of resveratrol in vivo were assessed using a transdermal test. The inhibitory effects of resveratrol suspension and microemulsion on tyrosinase activity and melanin production of A375 human melanocytes and zebrafish embryos were compared. A skin patch test was used to investigate the safety of the gel on 15 volunteers. RESULTS: The microemulsion gel was homogeneous and stable. Compared with suspension and microemulsion, the drug penetration rate and skin retention in the microemulsion gel group were significantly increased. Compared with the suspension group, the activity of melanocyte tyrosinase in A375 human melanocyte was significantly inhibited in the microemulsion group, and the melanin production rate of A375 human melanocyte and the melanin area of zebrafish yolk was decreased. All 15 volunteers tested negative for the human skin patch. CONCLUSIONS: The microemulsion gel could significantly enhance the ability of resveratrol to inhibit the formation of melanin without causing side effects. These data provide the experimental basis for developing and applying the preparation for improving pigmentation.

Adaptation and uniformity of monolithic zirconia crowns fabricated by additive 3-dimensional gel deposition.

STATEMENT OF PROBLEM: A novel monolithic zirconia restoration fabricated by additive 3-dimensional (3D) gel deposition, named as self-glazed zirconia (SGZ), has recently been developed. SGZ crowns exhibit reliable mechanical properties and esthetic appearance, but their adaptation and uniformity are unclear. PURPOSE: The purpose of this in vitro study was to compare the adaptation and uniformity of monolithic zirconia crowns fabricated by additive 3D gel deposition with that of milled zirconia and lithium disilicate crowns. MATERIAL AND METHODS: Ten identical resin abutments were made based on the scanning data of an extracted and prepared human mandibular first molar. Three types of monolithic crowns were then fabricated by using 2 different processes: 3D gel deposition zirconia (SGZ), milled zirconia (ZZ), and milled lithium disilicate (EMX) (n=10) through a completely digital workflow. The nondestructive direct-view technique and replica technique were used to measure the marginal and internal discrepancy values individually. The uniformity index was calculated to describe the uniformity of the internal space. The results were analyzed by using 1-way ANOVA and Kruskal-Wallis statistical tests (α=.05). RESULTS: The marginal discrepancy of EMX exhibited the highest values among the 3 groups (P=.001). The 2 types of zirconia crowns had comparable marginal discrepancy values (P>.05). The internal discrepancy values of SGZ were significantly lower than those of EMX at the occlusal region and of ZZ at all measured locations (P<.05). All 3 types of monolithic crowns showed comparable good uniformity (P=.056). CONCLUSIONS: The marginal and internal adaptations of novel monolithic zirconia crowns were within clinical requirements. Compared with the zirconia and lithium disilicate crowns fabricated by subtractive milling, monolithic zirconia crowns fabricated by additive 3D gel deposition had comparable uniformity and better internal adaptation.

Dental caries status and its associated factors among schoolchildren aged 6-8 years in Hangzhou, China: a cross-sectional study.

BACKGROUND: Dental caries prevalence reaches the first peak around 6 years old. It is necessary to take effective measures to prevent and treat caries at this stage. This study investigated the prevalence and associated factors of dental caries among schoolchildren aged 6-8 years in Hangzhou City, China. METHODS: A cross-sectional survey was conducted in Hangzhou from October 2017 to May 2018. Oral health status of schoolchildren in 1st and 2nd grades of primary schools aged 6-8 years was examined by well-trained examiners according to the WHO criteria. Questionnaires about potential caries-related factors were distributed to their parents. ANOVA test and logistic regression were conducted for the statistical analyses (α = 0.05). RESULTS: A total of 7959 pairs of schoolchildren and their parents were invited to participate, and 5595 were included in this study according to the eligible criteria (response rate: 70.3%). The overall prevalence and mean dmft/DMFT of dental caries in the investigated schoolchildren were 52.78% and 2.11. The prevalence and mean dmft/DMFT were 39.05% and 1.63 in the deciduous teeth, while these were 21.45% and 0.48 in the permanent teeth, respectively. For the first permanent molars (FPMs), the rate of fully eruption and pit and fissure sealing (PFS) were 79.09% and 6.60%, respectively. Multiple logistic regression showed that girl (OR = 1.12, 95% CI 1.01-1.25, p < 0.05), seldom or never brush teeth (OR = 2.36, 95% CI 1.08-5.44, p < 0.05), consuming sweet food or drink once or more time a day (OR = 1.14, 95% CI 1.00-1.29, p < 0.05; OR = 1.21, 95% CI 1.07-1.36, p < 0.05), dental visit experiences (OR = 1.58, 95% CI 1.35-1.86, p < 0.001) were positively and no tooth pain in the past 12 months (OR = 0.55, 95% CI 0.38-0.80, p < 0.05) were negatively associated with caries. CONCLUSIONS: Dental caries was prevalent among schoolchildren aged 6-8 years in Hangzhou, and was associated with gender, frequency of toothbrushing, sweet food or drink consuming, tooth pain and dental visit experiences. A large number of fully erupted FPMs did not receive timely PFS.

Artificial intelligence in the diagnosis of dental diseases on panoramic radiographs: a preliminary study.

BACKGROUND: Artificial intelligence (AI) has been introduced to interpret the panoramic radiographs (PRs). The aim of this study was to develop an AI framework to diagnose multiple dental diseases on PRs, and to initially evaluate its performance. METHODS: The AI framework was developed based on 2 deep convolutional neural networks (CNNs), BDU-Net and nnU-Net. 1996 PRs were used for training. Diagnostic evaluation was performed on a separate evaluation dataset including 282 PRs. Sensitivity, specificity, Youden's index, the area under the curve (AUC), and diagnostic time were calculated. Dentists with 3 different levels of seniority (H: high, M: medium, L: low) diagnosed the same evaluation dataset independently. Mann-Whitney U test and Delong test were conducted for statistical analysis (ɑ=0.05). RESULTS: Sensitivity, specificity, and Youden's index of the framework for diagnosing 5 diseases were 0.964, 0.996, 0.960 (impacted teeth), 0.953, 0.998, 0.951 (full crowns), 0.871, 0.999, 0.870 (residual roots), 0.885, 0.994, 0.879 (missing teeth), and 0.554, 0.990, 0.544 (caries), respectively. AUC of the framework for the diseases were 0.980 (95%CI: 0.976-0.983, impacted teeth), 0.975 (95%CI: 0.972-0.978, full crowns), and 0.935 (95%CI: 0.929-0.940, residual roots), 0.939 (95%CI: 0.934-0.944, missing teeth), and 0.772 (95%CI: 0.764-0.781, caries), respectively. AUC of the AI framework was comparable to that of all dentists in diagnosing residual roots (p > 0.05), and its AUC values were similar to (p > 0.05) or better than (p < 0.05) that of M-level dentists for diagnosing 5 diseases. But AUC of the framework was statistically lower than some of H-level dentists for diagnosing impacted teeth, missing teeth, and caries (p < 0.05). The mean diagnostic time of the framework was significantly shorter than that of all dentists (p < 0.001). CONCLUSIONS: The AI framework based on BDU-Net and nnU-Net demonstrated high specificity on diagnosing impacted teeth, full crowns, missing teeth, residual roots, and caries with high efficiency. The clinical feasibility of AI framework was preliminary verified since its performance was similar to or even better than the dentists with 3-10 years of experience. However, the AI framework for caries diagnosis should be improved.

All-In-One Biomimetic Nanoplatform Based on Hollow Polydopamine Nanoparticles for Synergistically Enhanced Radiotherapy of Colon Cancer.

Even though radiotherapy is the most important therapeutic strategy for colon cancer treatment, there is an enormous demand to improve radiosensitivity in solid tumor destruction. For this purpose, a biomimetic nanoplatform based on hollow polydopamine nanoparticles (HP) with homologous targeting and pH-responsive drug release properties is designed. In this work, HP is constructed by using a chelation competition-induced polymerization strategy and then modified with the cancer cell membrane. Hollow polydopamine integrated with Pt nanoparticles (Pt@HP) has a catalase-like activity, which can be used to trigger endogenous H2 O2 into O2 , relieving hypoxia of the tumor microenvironment (TME). With mesoporous shells and large cavities, Pt@HP shows efficient apoptin100-109 (AP) and verteporfin (VP) loading to form AVPt@HP@M. Under X-ray irradiation, AVPt@HP@M exerts a radiosensitization effect via multiple strategies, including relieving hypoxia (Pt NPs), enhancing tumor apoptosis (AP), and X-ray-induced photodynamic therapy (X-PDT) (VP). Further metabonomics analysis shows that the specific mechanism of the AVPt@HP@M is through influencing purine metabolism. Without appreciable systemic toxicity, this nanoplatform highlights a new strategy for effective radiosensitization and provides a reference for treating malignant tumors.

Hierarchical Assembly of Flexible Biopolymer Polyphosphate-Manganese into Nanosheets.

Polyphosphate (polyP) is one of the most compact inorganic polyanionic biopolymers that participates in various physiological processes. However, the development of polyP-based nanomaterials is still in its infancy. Here, biocompatible polyphosphate-manganese nanosheets are designed and synthesized by a hierarchical assembly strategy. The thickness and the lateral size of the resulting polyP-Mn nanosheets (PMNSs) are 5 nm and 120-130 nm, respectively. Molecular dynamics simulations suggested that the polyP-hexadecyl trimethyl ammonium bromide flat structure possesses a strong aggregating capacity and serves as the template for the 2D assembly of polyP-Mn. The PMNSs can activate the inflammatory response of macrophages resulting in the recovery of innate immunological functions to inhibit tumor proliferation. This work has initiated a new direction in constructing layered polyP-based nanomaterials and provides guidance for biocompatible and biodegradable biopolymer-based materials in the regulation of innate responses.

Stem cell contributions to cementoblast differentiation in healthy periodontal ligament and periodontitis.

Loss of tissue attachment as a consequence of bacterial infection and inflammation represents the main therapeutic target for the treatment of periodontitis. Cementoblasts, the cells that produce the mineralized tissue, cementum, that is responsible for connecting the soft periodontal tissue to the tooth, are a key cell type for maintaining/restoring tissue attachment following disease. Here, we identify two distinct stem cell populations that contribute to cementoblast differentiation at different times. During postnatal development, cementoblasts are formed from perivascular-derived cells expressing CD90 and perivascular-associated cells that express Axin2. During adult homeostasis, only Wnt-responsive Axin2+ cells form cementoblasts but following experimental induction of periodontal disease, CD90+ cells become the main source of cementoblasts. We thus show that different populations of resident stem cells are mobilized at different times and during disease to generate precursors for cementoblast differentiation and thus provide an insight into the targeting cells resident cells for novel therapeutic approaches. The differentiation of these stem cells into cementoblasts is however inhibited by bacterial products such as lipopolysaccharides, emphasizing that regeneration of periodontal ligament soft tissue and restoration of attachment will require a multipronged approach.

Bioinspired Phosphorylcholine Coating for Surface Functionalization of Interventional Biomedical Implants with Bacterial Resistance and Anti-Encrustation Properties.

Enhancing the lubrication property and bacterial resistance is extremely important for interventional biomedical implants to avoid soft tissue damage and biofilm formation. In this study, a zwitterionic phosphorylcholine coating (PMPC) was successfully developed to achieve surface functionalization of a polyurethane (PU)-based ureteral stent via subsurface "grafting from" photopolymerization. Typical surface characterizations such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and surface wettability and morphology analyses examined by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy demonstrated that the phosphorylcholine polymer was grafted on the substrate with a thickness of 180 nm. Additionally, the tribological experiment performed by a universal material tester showed that the lubrication performance of PU-PMPC was significantly improved compared with that of PU. The in vitro experiments indicated that the PMPC coating was biocompatible and stably modified on the surface of the substrate with an excellent bacterial resistance rate of >90%. Furthermore, the result of the in vivo experiment showed that the anti-encrustation performance of the surface-functionalized ureteral stent was better than that of the bare ureteral stent. The great enhancement in the lubrication, bacterial resistance, and anti-encrustation properties of the phosphorylcholine coating was thought to be due to the hydration effects of the zwitterionic charges. In summary, the bioinspired zwitterionic phosphorylcholine coating developed herein achieved significantly improved lubrication, bacterial resistance, and anti-encrustation performances and could be used as a convenient approach for surface functionalization of interventional biomedical implants.

A Chewing Gum Residue-Based Gel with Superior Mechanical Properties and Self-Healability for Flexible Wearable Sensor.

Chewing gum residue is hard to decompose and easy to cause pollution, which is highly desirable to realize recycling. In this paper, a chewing gum gel with enhanced mechanical properties and self-healing properties is prepared by using polyvinyl alcohol (PVA) as the backbone in chewing gum residue. The hydrogen bond and the borax ester bond are employed to construct reversible interaction to enhance the self-healing ability. The physical crosslinking is realized by further freeze-thaw treatment to improve its mechanical properties. The gel demonstrates high elongation at break of 610% and strength of 0.11 MPa, as well as excellent self-healing performance and recyclable properties. In particular, the gel with a fast signal response is successfully applied as a wearable strain sensor to monitor different types of human motion. The gel as a sensor exhibits self-healing properties suggesting superior safety and stability, and displays wide linear sensitivity (the gauge factor is 0.417 and 0.170). The gel can be further served to explore temperature changes, implying the application in temperature monitoring. This study develops a novel approach for the recycle and reuse of chewing gum residue. The obtained gel may be a promising candidate for the fabrication of flexible wearable sensor.