RESUMO
BACKGROUND: Periodontal ligament stem cells (PDLSCs) have been proposed as therapeutic candidates in periodontal diseases and periodontium defects. Paracrine factors of PDLSCs, namely, secretome, can contribute to tissue regeneration comparable to direct stem cell application. This study explored restoration effects of PDLSC-derived secretome/conditioned medium (PDLSC-CM) on PDLSCs themselves in an inflammatory microenvironment and identified its action mechanisms using proteomics and transcriptomic profiling. METHODS: PDLSC-CM was prepared from cells under healthy culture conditions. Mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were then performed to analyze the PDLSC-CM proteome. Osteogenic differentiation of PDLSCs under inflammatory conditions or in the presence of PDLSC-CM was then characterized in assays of alkaline phosphatase activity, intracellular calcium levels, protein expression of osteogenic markers, and matrix mineralization. Furthermore, the transcriptomic profile was assessed to identify significantly enriched signaling pathways and associated molecular networks by RNA sequencing. RESULTS: LC-MS/MS proteomics identified a total of 203 proteins and distinguished 187 significant protein changes in PDLSC-CM compared to control-CM. LPS-treated PDLSCs significantly attenuated osteogenic differentiation. When PDLSCs were treated with PDLSC-CM alone, their osteogenic activity was significantly upregulated compared to the control group. Moreover, the LPS-impaired osteogenesis of PDLSCs was reconstituted by PDLSC-CM treatment. RNA sequencing revealed 252, 1,326, and 776 differentially expressed genes in the control vs. LPS, control vs. PDLSC-CM, and LPS vs. LPS + PDLSC-CM groups, respectively. CONCLUSION: This study suggest that PDLSC-CM restores the osteogenic potential of PDLSCs in an inflammatory environment through secretory functions representing potential repair and regenerative mechanisms.
Assuntos
Ligamento Periodontal , Periodontite , Humanos , Osteogênese/genética , Meios de Cultivo Condicionados/farmacologia , Proteoma/farmacologia , Transcriptoma , Lipopolissacarídeos/farmacologia , Cromatografia Líquida , Secretoma , Espectrometria de Massas em Tandem , Células-Tronco , Diferenciação Celular , Células CultivadasRESUMO
BACKGROUND: Limited data are available regarding the association between psoriasis and common dental conditions. OBJECTIVES: To investigate the risk of potential dental comorbidities in patients with psoriasis. METHODS: We conducted a nationwide population-based cohort study to analyse the claims data of patients with psoriasis (n = 15 165) and age- and sex-matched controls (n = 75 825). The incidence risk of the following potential dental conditions was analysed: dental caries, pulp and periapical disease, periodontal disease, gingival changes and tooth loss. RESULTS: After adjusting for potential cofactors, the adjusted hazard ratios (aHRs) of dental caries [1.105; 95% confidence interval (CI) 1.078-1.132], pulp and periapical disease (1.07; 95% CI 1.044-1.096) and periodontal disease (1.108; 95% CI 1.088-1.129) were significantly higher than those in the control cohort (P < 0.001). However, among the subset of patients with psoriasis who received systemic antipsoriatic treatment (n = 4275), the aHR risk of all potential dental comorbidities was not significantly higher from that of the control cohort. CONCLUSIONS: Patients with psoriasis have an increased risk of dental comorbidities, and systemic antipsoriatic treatment may help mitigate this increased risk.
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Cárie Dentária , Psoríase , Humanos , Estudos de Coortes , Estudos Retrospectivos , Psoríase/complicações , Psoríase/epidemiologia , Incidência , República da Coreia/epidemiologia , Fatores de RiscoRESUMO
Peripheral nerve injuries are common neurological disorders, and the available treatment options, such as conservative management and surgical repair, often yield limited results. However, there is growing interest in the potential of using chitosan-based biopolymers as a novel therapeutic approach to treating these injuries. Chitosan-based biopolymers possess unique characteristics, including biocompatibility, biodegradability, and the ability to stimulate cell proliferation, making them highly suitable for repairing nerve defects and promoting nerve regeneration and functional recovery. Furthermore, these biopolymers can be utilized in drug delivery systems to control the release of therapeutic agents and facilitate the growth of nerve cells. This comprehensive review focuses on the latest advancements in utilizing chitosan-based biopolymers for peripheral nerve regeneration. By harnessing the potential of chitosan-based biopolymers, we can pave the way for innovative treatment strategies that significantly improve the outcomes of peripheral nerve injury repair, offering renewed hope and better prospects for patients in need.
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Quitosana , Traumatismos dos Nervos Periféricos , Humanos , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Quitosana/uso terapêutico , Tratamento Conservador , Biopolímeros/uso terapêutico , Proliferação de CélulasRESUMO
The aim of the present study was to elucidate the correlation between the International Caries Detection and Assessment System (ICDAS) and the Snyder caries activity test (SCAT) for the assessment of early dental caries in preschool children. Dental health status of 153 children aged 3-5 years was evaluated by oral examination. The ICDAS stage (enamel opacity stage to cavitated dentine caries stage (stages 1-6)) was assigned based on the evaluation of each tooth surface by a trained dentist based on the number of decayed (d) and filled teeth (ft). In this study, scores of d3-6t (t, teeth), d3-6s (s, tooth surface), d3-6ft and d3-6fs were the cut-off points for enamel caries, set to ICDAS code 3 (d3). SCAT score was assigned based on the acid production level of lactic acid bacteria in plaque (scores: 1-4). Linear correlation analysis was used to determine the correlation between ICDAS and SCAT scores. The proportion of children for each of the dental caries status were as follows: d0, 46.4%; d1-2, 28.1%; d3-4, 9.8%; d5-6, 15.7%. Regarding SCAT scores, 30%, 30.1%, 26.8% and 12.4% children had no, mild, moderate and severe caries activity, respectively. The d3-6t, d3-6s, d3-6ft and d3-6fs indices increased with age and were 0.56, 0.82, 2.03 and 5.05, respectively. Children with a higher SCAT score had higher ICDAS scores (p < 0.05). Our findings suggest that a combination of ICDAS and SCAT scores is beneficial for diagnosing caries progression and highly active caries. Early childhood caries should be managed early to prevent the enamel opacity stage to progress to cavitation.
Assuntos
Cárie Dentária , Dente , Humanos , Pré-Escolar , Cárie Dentária/diagnóstico , Estudos Transversais , Suscetibilidade à Cárie DentáriaRESUMO
OBJECTIVES: The aim of the study was to investigate patients with coronavirus disease 2019 (COVID-19) who visited dental clinics for treatment and to analyse the occurrence of additional COVID-19-confirmed cases according to the type of dental treatment and use of personal protective equipment (PPE). METHODS: Interviews were conducted in November 2021 via telephone, and written questionnaires were administered to dental hygienists working at the 24 dental clinics selected for the study, visited by patients with COVID-19. The survey focused on the visit date, the treatment received, whether or not the dental personnel wore PPE while treating the patient, and how the dental clinic and the public health centre with jurisdiction over the clinic responded after the patient's visit. RESULTS: Additional confirmed cases occurred in two of the 24 dental clinics included. In both cases, scaling was performed, dental personnel did not use a face shield, and patients with COVID-19 were asymptomatic. In 14 of the 22 dental clinics where additional confirmed cases did not occur, the dental personnel did not use face shields, and in 10 clinics, the dental personnel wore dental masks but not a KF94 mask. Based on these findings, which were obtained before the advent of the omicron variant, COVID-19 cross-infection did not appear to be high in dental clinics. CONCLUSION: The rate of COVID-19 cross-infection before the advent of the omicron variant appeared to be low in dental clinics in Korea. Therefore, patients have no reason to delay necessary dental treatment if dental personnel put effort into wearing PPE.
Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , SARS-CoV-2 , Clínicas Odontológicas , República da Coreia/epidemiologiaRESUMO
OBJECTIVES: This cross-sectional study was to determine the coronavirus disease 2019 (COVID-19) vaccination intention of clinical dental hygienists in South Korea and the factors that influence vaccination intention. METHODS: COVID-19 vaccination intention of the 500 participants was confirmed through a survey including the following options: 'I will vaccinate (VAC)', 'I will not vaccinate (NoVAC)' and 'I do not know if I should get vaccinated (UNK)'. A Chi-square test was performed to determine whether there were differences in COVID-19 vaccination intention according to the general characteristics of the participants, degree of infection control knowledge (Score-K) and practice (Score-P) in response to COVID-19, fears over COVID-19 (Fear-C) and the level of anxiety before (GADBefore ) and after (GADAfter ) the COVID-19 pandemic. Multiple logistic regression was performed to identify factors affecting VAC and NoVAC by setting the base category as UNK. The p-values of <0.05 were considered statistically significant. RESULTS: According to the analysis, 44.8%, 18.8% and 36.4% of participants selected VAC, NoVAC and UNK respectively. There were significant differences in vaccination intention according to age, monthly income, residential area, symptoms related to COVID-19, Score-K, Fear-C and GADBefore . Compared to UNK, < $2000 monthly income, Score-K and Fear-C variables significantly influenced the opinion of VAC. Compared to the answer UNK, monthly incomes of $2000 to $2360 and $2360 to $2730 in residential areas significantly influenced the opinion of NoVAC. CONCLUSIONS: The variables influencing vaccination intention were monthly income, residential area, Score-K and Fear-C.
Assuntos
COVID-19 , Intenção , Humanos , Pandemias , Vacinas contra COVID-19/uso terapêutico , Estudos Transversais , Higienistas Dentários , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinação , República da Coreia/epidemiologiaRESUMO
BACKGROUND: Studies using salivary inflammatory biomarkers for diagnosing and monitoring the progression of periodontal disease have garnered increased attention in recent years. The present study aimed to identify changes in clinical parameters and concentrations of salivary matrix metalloproteinases (MMPs) following 6 weeks of non-surgical periodontal therapy (NSPT). METHODS: A 6-week NSPT program was applied to 51 adults aged ≥ 20 years. The program involved scaling, root planing, and professional toothbrushing for healthy participants and those with periodontal disease. Patients with periodontal disease underwent professional toothbrushing during all three visits. Periodontal pocket depth (PD) and gingival bleeding were assessed at week 0, week 3, and week 6, and saliva samples were collected to measure the concentrations of MMP-3, -8, and -9. RESULTS: All clinical parameters were improved in the periodontal disease groups following the NSPT course. Compared with healthy participants, the patients with periodontal disease showed increased concentrations of salivary MMP-3, -8, and -9. During the 6-week program, patients with periodontal disease also showed significant reductions in PD and gingival bleeding during the third week; no significant reduction was found during the sixth week. Significant reductions in the concentrations of salivary MMP-3, -8, and -9 were also noted in the periodontal disease group at week 3. The sensitivity and specificity of MMP-3 for predicting periodontitis were 81.8% and 55.5%, respectively. CONCLUSION: The present study found that NSPT resulted in reductions of salivary MMP-3, -8, and -9, and identified the potential of MMP-3 as a biomarker in the diagnosis of periodontal disease. These findings may serve as foundational data for future studies into the development of diagnostic kits for periodontal disease.
Assuntos
Metaloproteinase 3 da Matriz , Doenças Periodontais , Adulto , Biomarcadores/análise , Líquido do Sulco Gengival/química , Hemorragia Gengival , Humanos , Metaloproteinase 3 da Matriz/uso terapêutico , Metaloproteinase 8 da Matriz , Metaloproteinase 9 da Matriz , Doenças Periodontais/terapia , Índice Periodontal , Bolsa Periodontal/tratamento farmacológicoRESUMO
BACKGROUND: Photothermal therapy (PTT) is an emerging anti-cancer therapeutic strategy that generates hyperthermia to ablate cancer cells under laser irradiation. Gold (Au) coated liposome (AL) was reported as an effective PTT agent with good biocompatibility and excretory property. However, exposed Au components on liposomes can cause instability in vivo and difficulty in further functionalization. RESULTS: Herein, we developed a theranostic dual-layered nanomaterial by adding liposomal layer to AL (LAL), followed by attaching polyethylene glycol (PEG) and radiolabeling. Functionalization with PEG improves the in vivo stability of LAL, and radioisotope labeling enables in vivo imaging of LAL. Functionalized LAL is stable in physiological conditions, and 64Cu labeled LAL (64Cu-LAL) shows a sufficient blood circulation property and an effective tumor targeting ability of 16.4%ID g-1 from in vivo positron emission tomography (PET) imaging. Also, intravenously injected LAL shows higher tumor targeting, temperature elevation in vivo, and better PTT effect in orthotopic breast cancer mouse model compared to AL. The tumor growth inhibition rate of LAL was 3.9-fold higher than AL. CONCLUSION: Based on these high stability, in vivo imaging ability, and tumor targeting efficiency, LAL could be a promising theranostic PTT agent.
Assuntos
Sistemas de Liberação de Medicamentos , Lipossomos/farmacologia , Nanoestruturas , Terapia Fototérmica/métodos , Medicina de Precisão/métodos , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Ouro/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias/tratamento farmacológico , Polietilenoglicóis , Tomografia por Emissão de Pósitrons , Nanomedicina Teranóstica/métodosRESUMO
Shikimate is a key intermediate in high demand for synthesizing valuable antiviral drugs, such as the anti-influenza drug and oseltamivir (Tamiflu®). Microbial-based shikimate production strategies have been developed to overcome the unstable and expensive supply of shikimate derived from traditional plant extraction processes. Although shikimate biosynthesis has been reported in several engineered bacterial species, the shikimate production yield is still unsatisfactory. This study designed an Escherichia coli cell factory and optimized the fed-batch culture process to achieve a high titer of shikimate production. Using the previously constructed dehydroshikimate (DHS)-overproducing E. coli strain, two genes (aroK and aroL) responsible for converting shikimate to the next step were disrupted to facilitate shikimate accumulation. The genes with negative effects on shikimate biosynthesis, including tyrR, ptsG, and pykA, were disrupted. In contrast, several shikimate biosynthetic pathway genes, including aroB, aroD, aroF, aroG, and aroE, were overexpressed to maximize the glucose uptake and intermediate flux. The shiA involved in shikimate transport was disrupted, and the tktA involved in the accumulation of both PEP and E4P was overexpressed. The rationally designed shikimate-overproducing E. coli strain grown in an optimized medium produced approximately 101 g/l of shikimate in 7-l fed-batch fermentation, which is the highest level of shikimate production reported thus far. Overall, rational cell factory design and culture process optimization for microbial-based shikimate production will play a key role in complementing traditional plant-derived shikimate production processes.
Assuntos
Células Artificiais , Escherichia coli , Vias Biossintéticas , Escherichia coli/genética , Engenharia Metabólica , Ácido ChiquímicoRESUMO
PURPOSE: TXA9, a novel cardiac glycoside, has a potent anti-proliferative effect against A549 human lung cancer cells, however, possesses a poor water-solubility and a rapid metabolic rate in vivo which limited the further development of TXA9. To overcome the shortcomings of TXA9, four polymer prodrugs of TXA9 were designed and synthesized. METHODS: Poly (ethylene glycol) monomethyl ether (mPEG) and α-tocopherol polyethylene glycol succinate (TPGS) were applied to modify TXA9 via carbonate ester and glycine linkers respectively to obtain four polymer prodrugs. The water-solubility and stability of prodrugs were studied in vitro while their pharmacokinetic behaviors and antitumor activity were investigated in vivo. RESULTS: The water-solubility of TXA9 was obviously increased and prodrugs with glycine linkers showed a better stability in rat plasma. Their pharmacokinetic investigation found that the t1/2 and AUC0-∞ of TPGS-Gly-TXA9 was increased by 80- and 9.6-fold compared with that of TXA9, which was more superior than the other three prodrugs. More importantly, the tumor inhibition rate of TPGS-Gly-TXA9 (43.81%) on A549 xenograft nude mice was significantly increased compared with that of TXA9 (25.26%). CONCLUSION: The above results suggested that TPGS-Gly-TXA9 possessed better antitumor efficiency than TXA9 and could be further investigated as an anti-cancer agent.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Glicosídeos Cardíacos/química , Glicosídeos Cardíacos/farmacologia , Polímeros/química , Polímeros/farmacologia , Células A549 , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Glicosídeos Cardíacos/farmacocinética , Glicosídeos Cardíacos/uso terapêutico , Desenho de Fármacos , Esterificação , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Camundongos Endogâmicos BALB C , Camundongos Nus , Polímeros/farmacocinética , Polímeros/uso terapêutico , Pró-Fármacos/química , Pró-Fármacos/farmacocinética , Pró-Fármacos/farmacologia , Pró-Fármacos/uso terapêutico , Ratos Sprague-Dawley , Solubilidade , Água/químicaRESUMO
OBJECTIVES: While common in the elderly, dry mouth can negatively affect their oral health and nutritional status. Self-administered oral care by the elderly can improve their oral health and prevent oral diseases. This study aimed to identify the content of oral health promotion programmes for community-dwelling elderly and to determine which programmes are effective in improving oral health decreasing xerostomia in these populations. METHODS: A systematic literature search and meta-analysis was conducted using the PRISMA guidelines. All available papers published in English or Korean were searched between 1 June and 13 June 2018. The relevant databases in PubMed Central, MEDLINE, CINAHL, the Cochrane Library and Embase, as well as open dissertation and academic searches, were performed. Data were extracted from the selected studies based on PICOS, and the health outcomes of the elderly were subjected to meta-analysis categorized by salivary secretion rates and oral health-related quality of life (OHQoL). RESULTS: A total of nine studies had sufficient data for a systematic review and meta-analysis. The intervention programmes consisted mainly of oral health promotion programmes, mouth exercises, toothbrushing and salivary massage. The meta-analysis indicated that elderly participating in oral health programmes had significantly increased oral salivary secretion rates and OHQoL (effect sizes of 0.63 and 0.80, respectively). CONCLUSIONS: Oral health promotion programmes in the elderly provide the positive effects of relieving dry mouth and improving OHQoL. This systematic review confirmed the contents and effects of the oral health promotion programmes provided to community-dwelling elderly.
Assuntos
Saúde Bucal , Xerostomia , Idoso , Humanos , Vida Independente , Qualidade de Vida , Escovação DentáriaRESUMO
INTRODUCTION: The association between nutrition and oral health has been studied in the elderly. This study aimed to examine the impacts of undernutrition and the mothers' socioeconomic and oral health statuses on the incidence of dental caries in Korean preschool children. METHODS: Data of 610 children aged 3-5 years and their mothers who underwent oral examinations and responded to the questionnaires in the 6th KNAHNES were used. Caries prevalence was measured by dft and dt among the primary teeth in children and DMFT among mothers. Dietary reference intake values were used to evaluate nutritional status, a nutritional quality index and the mean nutrient adequacy ratio. Complex sample correlation analysis was performed by using children's dft and dt statuses as dependent variables. Multilevel linear regression was applied to investigate the impacts of undernutrition and mothers' socioeconomic and oral health status on children's dft and dt statuses. Statistical significance was set as P < .05. RESULTS: Factors significantly related to dft in children were age and food. Food insecurity was the only factor significantly associated with dt in children. Children's sex and mother's DMFT were likely to be relevant to dft in children. Children's age and a nutritional quality index value less than 1 were also likely to be relevant to the dt of children. CONCLUSIONS: Children with an undernourished status had a higher caries experience. A comprehensive community dental health promotion programme should be developed to prevent the incidence of dental caries in vulnerable undernourished children.
Assuntos
Cárie Dentária , Saúde Bucal , Idoso , Pré-Escolar , Estudos Transversais , Índice CPO , Cárie Dentária/epidemiologia , Feminino , Humanos , Mães , Prevalência , República da Coreia/epidemiologia , Dente DecíduoRESUMO
BACKGROUND AND OBJECTIVES: Proteome analysis of periodontal ligament stem cells (PDLSCs) could be used to study the function of PDL tissue. We used a label-free quantitative proteomic technique to investigate differentially expressed proteins (DEPs) in human PDLSCs (hPDLSCs) compared to human bone marrow mesenchymal stem cells (hBMSCs) and identify proteins specific to hPDLSCs. MATERIAL AND METHODS: hPDLSCs (n = 3) and hBMSCs (n = 3) were cultured and harvested for protein extraction and trypsin digestion. The proteomes of both cell types were analyzed by nano-liquid chromatography/tandem mass spectrometry. DEPs in hPDLSCs compared to hBMSCs were detected by label-free quantification and evaluated through signal transduction pathway and gene ontology (GO) analysis. RESULTS: In total, 690 and 771 proteins were identified from hPDLSCs and hBMSCs, of which 561 proteins were in common and 124 DEPs were found between hPDLSCs and hBMSCs. Fifty-eight proteins were expressed at significantly higher levels in hPDLSCs, whereas 66 proteins were expressed at lower levels compared to hBMSCs. The more highly expressed proteins were associated with translation and initiating protein synthesis, and lower expressed proteins were related to cell aging and metabolic processes. Proteins unique to hPDLSCs and hBMSCs were associated with translation and metabolic processes, respectively. CONCLUSION: Our results demonstrate evidence of distinct differences in protein expression between hPDLSCs and hBMSCs by using label-free quantitative proteomic analysis which was the first attempt in this field. DEPs included previously reported hPDLSC marker proteins and novel marker candidates, such as microtubule-associated protein, CTP synthase 1 and stathmin, which could be the markers for developing periodontal disease diagnostics and therapies.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Células-Tronco/metabolismo , Espectrometria de Massas em Tandem , Proteínas Reguladoras de Apoptose , Biomarcadores/metabolismo , Carbono-Nitrogênio Ligases/metabolismo , Células Cultivadas , Cromatografia Líquida , Humanos , Células-Tronco Mesenquimais/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Doenças Periodontais/diagnóstico , Estatmina/metabolismo , Proteínas Supressoras de Tumor/metabolismoRESUMO
BACKGROUND: Opacification of hydrophobic and hydrophilic intraocular lenses (IOLs) has been reported. Herein, we report a case of spontaneous resolution of opacification following acute clouding of a trifocal IOL, which consisted of hydrophilic acrylic material (25%) with hydrophobic surface properties, occurring in a cold region in the winter season. CASE PRESENTATION: A young adult with bilateral radiation cataract underwent phacoemulsification using a femtosecond laser and implantation of a trifocal IOL. The trifocal IOL was delivered to the operating theatre 30 min before the surgery. The outside temperature was approximately - 7 °C. The IOL package was warmed using a radiator at approximately 35 °C for 15 min. After the optical region was implanted in the eye, cloudiness was observed, which persisted throughout the operation. Complete clearing of the IOL was apparent after three postoperative hours. CONCLUSION: In this case, rapid opacification and clearing of the IOL suggested an acute and transient process. IOLs should be stored and shipped at a constant temperature, and sudden temperature fluctuations should be avoided, especially in the colder seasons.
Assuntos
Resinas Acrílicas , Lentes Intraoculares Multifocais/efeitos adversos , Facoemulsificação/efeitos adversos , Complicações Pós-Operatórias/diagnóstico , Acuidade Visual , Doença Aguda , Adulto , Humanos , Masculino , Desenho de Prótese , Remissão EspontâneaRESUMO
Urethane groups formed by reacting phenolic hydroxyl groups with isocyanates are known to be reversible at high temperatures. To investigate the intrinsic self-healing of polyurethane via a reversible urethane group, we synthesized vanillyl alcohol (VA)-based polyurethanes. The phenolic hydroxyl group of vanillyl alcohol allows the introduction of a reversible urethane group into the polyurethane backbone. Particularly, we investigated the effects of varying the concentration of reversible urethane groups on the self-healing of the polyurethane, and we proposed a method that improved the mobility of the molecules contributing to the self-healing process. The concentration of reversible urethane groups in the polyurethanes was controlled by varying the vanillyl alcohol content. Increasing the concentration of the reversible urethane group worsened the self-healing property by increasing hydrogen bonding and microphase separation, which consequently decreased the molecular mobility. On the other hand, after formulating a modified chain extender (m-CE), hydrogen bonding and microphase separation decreased, and the mobility (and hence the self-healing efficiency) of the molecules improved. In VA40-10 (40% VA; 10% m-CE) heated to 140 °C, the self-healing efficiency reached 96.5% after 30 min, a 139% improvement over the control polyurethane elastomer (PU). We conclude that the self-healing and mechanical properties of polyurethanes might be tailored for applications by adjusting the vanillyl alcohol content and modifying the chain extender.
Assuntos
Álcoois Benzílicos/química , Elastômeros/química , Poliuretanos/química , Uretana/química , Peso Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , TermogravimetriaRESUMO
Polyurethane (PU) is a versatile polymer used in a wide range of applications. Recently, imparting PU with self-healing properties has attracted much interest to improve the product durability. The self-healing mechanism conceivably occurs through the existence of dynamic reversible bonds over a specific temperature range. The present study investigates the self-healing properties of 1,4:3,6-dianhydrohexitol-based PUs prepared from a prepolymer of poly(tetra-methylene ether glycol) and 4,4'-methylenebis(phenyl isocyanate) with different chain extenders (isosorbide or isomannide). PU with the conventional chain extender 1,4-butanediol was prepared for comparison. The urethane bonds in 1,4:3,6-dianhydrohexitol-based PUs were thermally reversible (as confirmed by the generation of isocyanate peaks observed by Fourier transform infrared spectroscopy) at mildly elevated temperatures and the PUs showed good mechanical properties. Especially the isosorbide-based polyurethane showed potential self-healing ability under mild heat treatment, as observed in reprocessing tests. It is inferred that isosorbide, bio-based bicyclic diol, can be employed as an efficient chain extender of polyurethane prepolymers to improve self-healing properties of polyurethane elastomers via reversible features of the urethane bonds.
Assuntos
Elastômeros/síntese química , Isossorbida/síntese química , Poliuretanos/síntese química , Temperatura , Varredura Diferencial de Calorimetria , Módulo de Elasticidade , Elastômeros/química , Isossorbida/química , Microscopia de Força Atômica , Peso Molecular , Poliuretanos/química , Espalhamento a Baixo Ângulo , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Termogravimetria , Difração de Raios XRESUMO
Combination therapy as a novel strategy with the combination of photothermal therapy and chemotherapy (photothermal-chemotherapy) has aroused the tremendously increasing interest owing to the synergistic therapeutic effect on destroying cancer cells because the hyperthermia generated from photothermal therapy can promote drug delivery into tumors, which would highly increase therapeutic efficacy as compared to those sole treatments. Herein, we fabricated a novel nanomaterial-based carrier composed of gold nanorods (GNRs), polypyrrole (PPy), and mesoporous silica to form GNRs/PPy/m-SiO2 core/shell hybrids. After loading the anticancer drug of doxorubicin (DOX), the photothermal effect and the drug-release behavior of GNRs/PPy@m-SiO2-DOX hybrids were investigated. The in vitro and in vivo near-infrared (NIR) photothermal-chemotherapy were also revealed. The results indicated that the NIR-induced photothermal effect was beneficial to promote the release of the drug. In addition, combination therapy demonstrated the enhanced synergistic efficacy and excellent treatment efficacy for cancer therapy.
Assuntos
Doxorrubicina/química , Portadores de Fármacos/química , Ouro/química , Nanotubos/química , Fototerapia , Polímeros/química , Pirróis/química , Dióxido de Silício/química , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Humanos , PorosidadeRESUMO
Azomethine diols (AMDs) were synthesized by condensation between a terephthalic aldehyde, polyether diamine, and ethanol amine. The synthesized AMDs were employed to introduce azomethine groups into the backbones of polyurethane elastomers (PUEs). Different AMDs were designed to control the concentration and distribution of azomethine groups in PUEs. In this study, we explored the intrinsic self-healing of AMD-based PUEs by azomethine metathesis. Particularly, the effects of the concentration and distribution of the azomethine groups on the AMD-based PUEs were considered. Consequently, as the azomethine group concentration increased and the distribution became denser, the self-healing properties improved. With AMD3-40, the self-healing efficiency reached 86% at 130 °C after 30 min. This represents a 150% improvement over the control PUE. Additionally, as the AMD content increased, the mechanical properties improved. With AMD3-40, the tensile strength reached 50 MPa. Therefore, we concluded that the self-healing and mechanical properties of PUEs can potentially be tailored for applications by adjusting the concentration and design of AMD structure for PUEs.
Assuntos
Compostos Azo/química , Poliuretanos/química , Tiossemicarbazonas/química , Cromatografia Líquida , Elastômeros/química , Espectrometria de Massas , Fenômenos Mecânicos , Peso Molecular , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , TermogravimetriaRESUMO
BACKGROUND: Oral health greatly affects well-being throughout the different stages of life from childhood to late adulthood. Loss of teeth due to poor oral health hinders mastication, leading to poor nutrition absorption, and affects pronunciation and aesthetics, leading to interpersonal difficulties. As social activities become limited, a sense of isolation and loneliness, stress, and depression grows while happiness decreases. This study aimed to examine the association of stress, depression, and suicidal ideation with oral health status and oral functions in a large nationwide sample of Korean adults aged 35 years or more. METHODS: The sample comprised 15,716 adults, selected using a rolling survey sampling method and data were extracted from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES) (2010-2012). Participants were interviewed about their self-evaluation of health including oral health status and mental health, such as stress, depression, and suicidal ideation. Data from 11,347 adults were finally selected after excluding participants with missing answers. The dependent variables were stress, depression, and suicidal ideation. The independent variables were gender, age, household income, education, smoking, drinking, oral health perception, chewing, and speaking. Complex samples logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Participants met the criteria for stress (25.4%), depression (13.0%), and suicidal ideation (13.9%). Subjective oral health status was not significantly associated with stress, depression, and suicidal ideation. However, the presence of very uncomfortable chewing problems was significantly associated with stress (OR = 2.294, 95% CI = 1.41, 3.72), depression (OR = 3.232, 95% CI = 1.97, 5.31), and suicidal ideation (OR = 2.727, 95% CI = 1.58, 4.72). The presence of very uncomfortable speaking problems was significantly associated with stress (OR = 1.592, 95% CI = 1.13, 2.24) but not significantly associated with depression and suicidal ideation. CONCLUSIONS: Oral functional problems including chewing and speaking difficulties can be associated with mental health. It is necessary to develop oral health promotion programs for adults and help them maintain a good quality of life and mental health.
Assuntos
Depressão/epidemiologia , Saúde Bucal , Estresse Psicológico/epidemiologia , Ideação Suicida , Adulto , Idoso , Depressão/complicações , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Saúde Bucal/estatística & dados numéricos , República da Coreia/epidemiologia , Estresse Psicológico/complicaçõesRESUMO
The purpose of the present study was to investigate the in vitro cardiomyogenic differentiation potential of human dental follicle-derived stem cells (DFCs) under the influence of suberoylanilide hydroxamic acid (SAHA), a member of the histone deacetylase inhibitor family, and analyze the in vivo homing capacity of induced cardiomyocytes (iCMs) when transplanted systemically. DFCs from extracted wisdom teeth showed mesenchymal stem cell (MSC) characteristics such as plate adherent growing, expression of MSC markers (CD44, CD90, and CD105), and mesenchymal lineage-specific differentiation potential. Adding SAHA to the culture medium induced the successful in vitro differentiation of DFCs into cardiomyocytes. These iCMs expressed cardiomyogenic markers, including alpha-smooth muscle actin (α-SMA), cardiac muscle troponin T (TNNT2), Desmin, and cardiac muscle alpha actin (ACTC1), at both the mRNA and protein level. For the assessment of homing capacity, PKH26 labeled iCMs were intraperitoneally injected (1×106 cells in 100 µL of PBS) into the experimental mice, and the ratios of PKH26 positive cells to the total number of injected cells, in multiple organs were determined. The calculated homing ratios, 14 days after systemic cell transplantation, were 5.6 ± 1.0%, 3.6 ± 1.1%, and 11.6 ± 2.7% in heart, liver, and kidney respectively. There was no difference in the serum levels of interleukin-2 and interleukin-10 at 14 days after transplantation, between the experimental (iCM injected) and control (no injection or PBS injection) groups. These results demonstrate that DFCs can be an excellent source for cardiomyocyte differentiation and regeneration. Moreover, the iCMs can be delivered into heart muscle via systemic administration without eliciting inflammatory or immune response. This can serve as the pilot study for further investigations into the in vitro cardiomyogenic differentiation potential of DFCs under the influence of SAHA and the in vivo homing capacity of the iCMs into the heart muscle, when injected systemically.