Amphiphilic Block Copolymer PCL-PEG-PCL as Stationary Phase for Capillary Gas Chromatographic Separations.

This work presents the first example of utilization of amphiphilic block copolymer PCL-PEG-PCL as a stationary phase for capillary gas chromatographic (GC) separations. The PCL-PEG-PCL capillary column fabricated by static coating provides a high column efficiency of 3951 plates/m for n-dodecane at 120 °C. McReynolds constants and Abraham system constants were also determined in order to evaluate the polarity and possible molecular interactions of the PCL-PEG-PCL stationary phase. Its selectivity and resolving capability were investigated by using a complex mixture covering analytes of diverse types and positional, structural, and cis-/trans-isomers. Impressively, it exhibits high resolution performance for aliphatic and aromatic isomers with diverse polarity, including those critical isomers such as butanol, dichlorobenzene, dimethylnaphthalene, xylenol, dichlorobenzaldehyde, and toluidine. Moreover, it was applied for the determination of isomer impurities in real samples, suggesting its potential for practical use. The superior separation performance demonstrates the potential of PCL-PEG-PCL and related block copolymers as stationary phases in GC and other separation technologies.

Early childhood caries prevalence and associated factors among preschoolers aged 3-5 years in Xiangyun, China: A cross-sectional study.

Purpose: This study aimed to investigate the early childhood caries (ECC) prevalence among preschoolers aged 3-5 years in Xiangyun of Yunnan, China and explore the factors associated with the prevalence. Materials and methods: A cross-sectional survey including 3-5-year-old children was conducted in Xiangyun County, China, between September and November 2020. According to the dental examination standard of the WHO 2013 criteria, the presence of ECC was recorded. Besides the dental examination for children, their parents completed questionnaires about caries-related factors, including demographic variables, family socioeconomic status, feeding, and oral health-related habits, parental dental knowledge, and the condition of dental service utilization. SPSS Statistics 25.0 (IBM, Chicago, IL, USA) was used for data analysis. Statistical significance was set at p < 0.05. Results: The ECC prevalence among a sample of 1,280 children aged 3-5 years consisting of 665 boys and 615 girls in this study, was 74.3%, and the mean decayed-missing-filled teeth (dmft) was 4.9 ± 5.0. There were no statistically significant differences in the ECC prevalence between the sexes and among different ethnic groups. Children with different dietary and oral hygiene habits showed no significantly different prevalence of ECC. Logistic regression analysis showed that the most significantly associated factors were older age, lower family income, and worse parental perception of children's oral health status. Conclusion: The ECC prevalence among 3-5-year-old preschool children in Xiangyun was higher than the average national ECC prevalence in China. This study implies that more attention should be given to children's caries prevention from early childhood; oral health education and promotion should be intensified to reduce the ECC prevalence and improve the oral health status of children in Xiangyun.

Characteristics of Oral Mucosal Lesions and Their Association With Socioeconomic Status and Systemic Health: A Cross-Sectional Study of Consecutively Collected Oral Medicine Clinic Data in a Remote Rural Area of China.

Objectives: Epidemiological data of oral mucosal lesions (OMLs) are required to develop practical oral care policies. However, limited data are available for rural areas in China. We aimed to estimate the spectrum and frequency of OMLs and to identify their associated socioeconomic status (SES) and systemic health in a remote rural area in Yunnan, China. Methods: We screened patients for OMLs in an oral medicine clinic in rural Yunnan, China, from August 2020 to February 2021. OMLs were documented. SES, including the highest education level achieved and the previous month's household income, as well as the patient's systemic health, including a history of smoking, alcohol use, and chronic disease, were obtained from the Medical History/Health Questionnaire Form and patient medical records. Results: A total of 146 patients were found to have OMLs. The most frequent OML was aphthous ulcer (n = 41, 28.1%), followed by burning mouth syndrome (BMS) (n = 16, 11.0%), viral ulcer (n = 14, 9.6%), and oral lichen planus (OLP) (n = 9, 6.2%). In these patients, the most common chronic diseases were sleep apnea (n = 35, 24.0%), hypertension (n = 23, 15.8%), bronchitis (n = 16, 11.0%), reflux (including gastroesophageal reflux disease) (n = 12, 8.2%), and arthritis (n = 11, 7.5%). On adjusted regression, the patients without chronic diseases had a lower risk of BMS than those with chronic diseases [odds ratio (OR), 0.2; 95% confidence interval (CI), 0.03-0.9]. Age was an independent protective factor for viral ulcers (OR, 1.0; 95% CI, 0.9-1.0). Patients with low-income levels had a lower risk of OLP than those with high-income levels (OR, 0.2; 95% CI, 0.05-0.9). Conclusions: Our oral medicine clinic data in remote Yunnan, China, showed the most frequent OML was aphthous ulcer, which was followed by BMS, viral ulcer, and OLP. Oral care policies should be prioritized among patients with aphthous ulcer. Preventive strategy of BMS should be targeted to people with chronic disease for health equalities. Therefore, an individualized strategy for interventions of OMLs might be optimal, based on the specific epidemiologic characteristics in rural settings.

Caries prevalence of the first permanent molar and associated factors among second-grade students in Xiangyun of Yunnan, China: A cross-sectional study.

Purpose: This study aimed to explore the caries prevalence of the first permanent molar (FPM) and the associated factors among second-grade students in Xiangyun of Yunnan, China. Materials and methods: A cross-sectional survey was conducted in Xiangcheng Town, Xiangyun County, China, from September to November 2020. The methodology recommended by WHO was used for the dental examination. All the parents were required to complete a questionnaire to collect information on children's family background, dietary habits, oral health behaviors and parental oral health-related knowledge. The tests of significance used were the chi-square test. The association between dental caries prevalence and its associated factors was investigated using logistic regression analysis. Statistical significance was set at P < 0.05. Results: Data of 1,295 second graders consisting of 665 males and 630 females were analyzed. The caries prevalence of FPM was 47.6%, and the mean DMFT was 1.11 ± 1.394 in this sample. Among all the children with caries, the filling rate is meager, 2.6%. There were statistically significant differences in the caries prevalence of FPM among age groups. No significant difference existed between the sexes. Logistic regression analysis showed that the most significantly associated factors were: consuming desserts at least once a day, no fluoride varnish application experience, worse parental perception of children's oral health status, and incorrect parental knowledge of whether decayed primary teeth need treatment. Conclusion: Caries prevalence of FPM among second-grade schoolchildren in Xiangyun was considerably higher than the average prevalence nationwide in China. As China aims to reduce dental caries to <25% of 12-year-old children in 2030, the local government of remote regions like Xiangyun needs to do much more to achieve this goal. Results of this study could provide a framework for ongoing and future public oral health programs and policy planning in Xiangyun, with particular attention to early preventive and therapeutic measures.

Construction of arsenic-metal complexes loaded nanodrugs for solid tumor therapy: A mini review.

Arsenic trioxide (As2O3), a front-line therapeutic agent against acute promyelocytic leukemia, has a broad spectrum against malignancies. Unfortunately, the clinical application of As2O3 in treating hematological cancers has not been transformed to solid tumors, for its dose-limited toxicity and undesirable pharmacokinetics. The ordinary As2O3 loaded nanodrugs (such as liposomes, polymer micelles, albumin-based nanodrugs, and silica-based nanodrugs, etc.) still could not fuel up pharmaceuticals and eradicate toxicity for low delivery efficiency caused by the instability and severe drug leakage of formulations during circulation. Recently, the approach of forming and delivering arsenic-metal complexes which will dissociate in the tumoral environment caught our mind. This is the most effective strategy to reduce drug leakage in circulation and accumulate arsenite ions in tumor sites, therefore promote the anti-tumor effect and lighten the toxicity of the drug. This review aims to explain the formation mechanism of arsenic-metal nanocomposites and summarize the constructing strategies of the arsenic-metal nanocomplexes (arsenic-nickel, arsenic-manganese, arsenic-platinum, arsenic-gadolinium, arsenic-zinc, and arsenic-iron nanobins) loaded nanodrugs for solid tumor therapy. Furthermore, the expectations and challenges of arsenic-metal complexes containing nanodrugs for cancer therapy in the future were discussed.

Self-Assembly of Succinated Paclitaxel into Supramolecular Hydrogel for Local Cancer Chemotherapy.

In the present study, we reported the generation of a molecular hydrogel of succinated paclitaxel (PTX-SA) by a self-hydrolytic strategy for potential local cancer chemotherapy. Upon self-hydrolysis of the ester bond of PTX-SA in phosphate-buffered saline (pH = 7.4) for 24 h, a PTX-SA supramolecular hydrogel formed spontaneously with a minimal gelation concentration of 0.25 wt%. The formed PTX-SA supramolecular hydrogel displayed a filamentous nanostructure, the nanofibers of which were typically several micrometers in length with a diameter of 10-15 nm. Rheological analysis suggested that the PTX-SA supramolecular hydrogel exhibited dominant elastic and thixotropic properties. Ionization of the carboxylate group together with the self-hydrolysis of the ester bond in PTX-SA are the major driving forces for the hydrogelation, as indicated by Fourier transform infrared spectroscopy (FTIR) analysis. The bioactive drug payload sustainably released from the supramolecular hydrogel over a period of 15 day in an in vitro release study, and the drug-release behavior could be finely controlled by altering the initial PTX-SA concentration. More importantly, the formed PTX-SA supramolecular hydrogel without compromising its pharmacological activity could efficiently inhibit the proliferation of cancer cells (HepG2 and MCF-7 cells) in vitro. Therefore, the generated PTX-SA supramolecular hydrogel might provide great potential as a novel drug-delivery system for local anti-cancer therapy.

Directing the nanoparticle formation by the combination with small molecular assembly and polymeric assembly for topical suppression of ocular inflammation.

In this paper, we presented a simple yet versatile strategy to generate a high drug payload nanoparticles by the combination with small molecular assembly and polymeric assembly for topical suppression of ocular inflammation. Upon physical mixing of the succinated triamcinolone acetonide (TA-SA) supramolecular hydrogel with the poly (ethylene glycol)-poly (ɛ-caprolactone)-poly (ethylene glycol) (PECE) aqueous solution at 37 °C, TA-SA/PECE nanoparticles formed spontaneously and characterized thoroughly by transmission electron microscopy (TEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The formed TA-SA/PECE nanoparticles displayed a comparable in vitro anti-inflammatory efficacy to that of native triamcinolone acetonide (TA), through a significant downregulation of various proinflammatory cytokines levels (e.g., NO, TNF-α) in a lipopolysaccharide (LPS) actived RAW264.7 macrophage. Meanwhile, the enhanced transcorneal drug permeability of TA-SA/PECE nanoparticles over that of TA suspension was clearly observed in an isolated rabbit cornea. Intraocular biocompatibility test demonstrated that TA-SA/PECE nanoparticles presented good biocompatibility after topical instillation during entire study period. More importantly, the TA-SA/PECE nanoparticles displayed superior therapeutic efficacy over that of the TA suspension in the endotoxin-induced uveitis (EIU) rabbit model via decreasing neutrophil infiltration in anterior chamber. Overall, the proposed TA-SA/PECE nanoparticles might be a promising candidate for uveitis therapy.

Glycosylation-enhanced biocompatibility of the supramolecular hydrogel of an anti-inflammatory drug for topical suppression of inflammation.

Intravitreal/periocular injection of triamcinolone acetonide (TA) suspension is a common uveitis treatment, but it displays a high risk for serious side effects (e.g., high intraocular pressure, retinal toxicity). We report here an intravitreally injectable thermosensitive glycosylated TA (TA-SA-Glu) hydrogel, formed by covalently conjugating glucosamine (Glu) with succinate TA (TA-SA), for treating uveitis. The TA-SA-Glu hydrogelator forms a supramolecular hydrogel spontaneously in aqueous solution with a minimal gelation concentration of 0.25 wt%. Structural analysis revealed that hydrogen bonds assisted by hydrophobic interaction resulted in self-assembled nanofibers. Rheology analysis demonstrated that this TA-SA-Glu hydrogel exhibited a typical thixotropic property. Sustained release of both TA-SA-Glu and TA from the hydrogel occurred throughout the 3-day in vitro release study. The obtained TA-SA-Glu hardly caused cytotoxicity against ARPE-19 and RAW264.7 cells after 24 h of incubation at drug concentration up to 600 µM. In particular, TA-SA-Glu exhibited a comparable anti-inflammatory efficacy to TA in terms of inhibiting the production of nitric oxide, tumor necrosis factor-α, and interleukin-6 in activated RAW264.7 macrophages. Following a single intravitreal injection, 69 nmol TA-SA-Glu hydrogel caused minimal apparent retinal toxicity, whereas the TA suspension displayed significant effects in terms of localized retinal toxicity. A single intravitreal injection of TA-SA-Glu hydrogel was more effective in controlling inflammatory response than that of the TA suspension treatment, particularly in down-regulating the pro-inflammatory Th1 and Th17 effector responses for treating experimental autoimmune uveitis. This study strongly indicates that supramolecular TA-SA-Glu hydrogels may represent a new option for posterior uveitis management. STATEMENT OF SIGNIFICANCE: Intravitreal/periocular injection of triamcinolone acetonide (TA) suspension is a common uveitis treatment, but suffers a high risk for serious side effects (e.g., high intraocular pressure, retinal toxicity). We generated an injectable glycosylated triamcinolone acetonide hydrogelator (TA-SA-Glu) hydrogel for treating uveitis. Following a single intravitreal injection, the proposed TA-SA-Glu hydrogel hardly caused apparent retinal toxicity at a dosage of 69 nmol per eye. Furthermore, TA-SA-Glu hydrogel was more effective in controlling non-infectious uveitis over than a TA suspension, particularly in terms of down-regulating the pro-inflammatory Th1 and Th17 effector responses for treating experimental autoimmune uveitis (EAU). This study strongly indicates that TA-SA-Glu supramolecular hydrogels may represent a new option for the management of various intraocular inflammations.