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1.
Macromol Biosci ; 23(11): e2300177, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37466165

RESUMO

The present study expands the versatility of cationic poly(2-oxazoline) (POx) copolymers as a polyethylene glycol (PEG)-free platform for gene delivery to immune cells, such as monocytes and macrophages. Several block copolymers are developed by varying nonionic hydrophilic blocks (poly(2-methyl-2-oxazoline) (pMeOx) or poly(2-ethyl-2-oxazoline) (pEtOx), cationic blocks, and an optional hydrophobic block (poly(2-isopropyl-2-oxazoline) (iPrOx). The cationic blocks are produced by side chain modification of 2-methoxy-carboxyethyl-2-oxazoline (MestOx) block precursor with diethylenetriamine (DET) or tris(2-aminoethyl)amine (TREN). For the attachment of a targeting ligand, mannose, azide-alkyne cycloaddition click chemistry methods are employed. Of the two cationic side chains, polyplexes made with DET-containing copolymers transfect macrophages significantly better than those made with TREN-based copolymer. Likewise, nontargeted pEtOx-based diblock copolymer is more active in cell transfection than pMeOx-based copolymer. The triblock copolymer with hydrophobic block iPrOx performs poorly compared to the diblock copolymer which lacks this additional block. Surprisingly, attachment of a mannose ligand to either copolymer is inhibitory for transfection. Despite similarities in size and design, mannosylated polyplexes result in lower cell internalization compared to nonmannosylated polyplexes. Thus, PEG-free, nontargeted DET-, and pEtOx-based diblock copolymer outperforms other studied structures in the transfection of macrophages and displays transfection levels comparable to GeneJuice, a commercial nonlipid transfection reagent.


Assuntos
Manose , Polietilenoglicóis , Polietilenoglicóis/química , Ligantes , Plasmídeos/genética , Polímeros/química , DNA/química , Transfecção
2.
ACS Macro Lett ; 12(8): 1100-1105, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37470677

RESUMO

Here, we report an oxygen-tolerant photografting technique to grow polymer brushes employing microliter volumes of monomer solution under ambient conditions. With the key advantages that include spatial control, initiator/catalyst-free nature, and high oxygen tolerance, a series of homo-, multiblock, and arbitrary patterned polymer brushes were successfully obtained by photografting. Moreover, a dual-functional surface with hydrophilic and hydrophobic properties could easily be realized by one-pot photografting. These results illustrated the practicality and versatility of this strategy, which will allow nonexperts access to polymer brush architectures and broaden the potential applications of polymer brushes.

3.
Adv Sci (Weinh) ; 10(25): e2300299, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37434063

RESUMO

Immune checkpoint blockade reaches remarkable clinical responses. However, even in the most favorable cases, half of these patients do not benefit from these therapies in the long term. It is hypothesized that the activation of host immunity by co-delivering peptide antigens, adjuvants, and regulators of the transforming growth factor (TGF)-ß expression using a polyoxazoline (POx)-poly(lactic-co-glycolic) acid (PLGA) nanovaccine, while modulating the tumor-associated macrophages (TAM) function within the tumor microenvironment (TME) and blocking the anti-programmed cell death protein 1 (PD-1) can constitute an alternative approach for cancer immunotherapy. POx-Mannose (Man) nanovaccines generate antigen-specific T-cell responses that control tumor growth to a higher extent than poly(ethylene glycol) (PEG)-Man nanovaccines. This anti-tumor effect induced by the POx-Man nanovaccines is mediated by a CD8+ -T cell-dependent mechanism, in contrast to the PEG-Man nanovaccines. POx-Man nanovaccine combines with pexidartinib, a modulator of the TAM function, restricts the MC38 tumor growth, and synergizes with PD-1 blockade, controlling MC38 and CT26 tumor growth and survival. This data is further validated in the highly aggressive and poorly immunogenic B16F10 melanoma mouse model. Therefore, the synergistic anti-tumor effect induced by the combination of nanovaccines with the inhibition of both TAM- and PD-1-inducing immunosuppression, holds great potential for improving immunotherapy outcomes in solid cancer patients.


Assuntos
Melanoma , Macrófagos Associados a Tumor , Camundongos , Animais , Linhagem Celular Tumoral , Imunoterapia , Linfócitos T CD8-Positivos , Microambiente Tumoral
4.
J Clin Periodontol ; 49(7): 642-653, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35569026

RESUMO

AIM: This study aimed to identify the factors influencing the changes in the number of teeth present and the number of healthy or filled surfaces between two time points. MATERIALS AND METHODS: Repeated cross-sectional data from population-based studies, namely the German Oral Health Studies (DMS-III vs. DMS-V), the Studies of Health in Pomerania (SHIP-START-0 vs. SHIP-TREND-0), and the Jönköping study (2003 vs. 2013), were analysed. Oaxaca decomposition models were constructed for the outcomes (number of teeth, number of healthy surfaces, and number of filled surfaces). RESULTS: The number of teeth increased between examinations (DMS: +2.26 [adults], +4.92 [seniors], SHIP: +1.67, Jönköping: +0.96). Improvements in education and dental awareness brought a positive change in all outcomes. An increase in powered toothbrushing and inter-dental cleaning had a great impact in DMS (adults: +0.25 tooth, +0.78 healthy surface, +0.38 filled surface; seniors: +1.19 teeth, 5.79 healthy surfaces, +0.48 filled surface). Inter-dental cleaning decreased by 4% between SHIP-START-0 and SHIP-TREND-0, which negatively affected the outcomes. CONCLUSIONS: From this study, it can be concluded that education may be the most important factor having a direct and indirect effect on the outcomes. However, for better oral health, powered toothbrushing and inter-dental cleaning should not be neglected.


Assuntos
Cárie Dentária , Perda de Dente , Adulto , Estudos Transversais , Humanos , Saúde Bucal , Perda de Dente/epidemiologia , Escovação Dentária
5.
Langmuir ; 38(17): 5226-5236, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35166545

RESUMO

The structures of a molecular brush in a good solvent are investigated using synchrotron small-angle X-ray scattering in a wide range of concentrations. The brush under study, PiPOx239-g-PnPrOx14, features a relatively long poly(2-isopropenyl-2-oxazoline) (PiPOx) backbone and short poly(2-n-propyl-2-oxazoline) (PnPrOx) side chains. As a solvent, ethanol is used. By model fitting, the overall size and the persistence length as well as the interaction length and interaction strength are determined. At this, the interplay between form and structure factor is taken into account. The conformation of the molecular brush is traced upon increasing the solution concentration, and a rigid-to-flexible transition is found near the overlap concentration. Finally, the results of computer simulations of the molecular brush solutions confirm the experimental results.


Assuntos
Solventes , Simulação por Computador , Conformação Molecular , Solventes/química
6.
J Funct Biomater ; 13(1)2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35076515

RESUMO

Bone tissue defects resulting from periodontal disease are often treated using guided tissue regeneration (GTR). The barrier membranes utilized here should prevent soft tissue infiltration into the bony defect and simultaneously support bone regeneration. In this study, we designed a degradable poly(l-lactide-co-glycolide) (PLGA) membrane that was surface-modified with cell adhesive arginine-glycine-aspartic acid (RGD) motifs. For a novel method of membrane manufacture, the RGD motifs were coupled with the non-ionic amphiphilic polymer poly(2-oxazoline) (POx). The RGD-containing membranes were then prepared by solvent casting of PLGA, POx coupled with RGD (POx_RGD), and poly(ethylene glycol) (PEG) solution in methylene chloride (DCM), followed by DCM evaporation and PEG leaching. Successful coupling of RGD to POx was confirmed spectroscopically by Raman, Fourier transform infrared in attenuated reflection mode (FTIR-ATR), and X-ray photoelectron (XPS) spectroscopy, while successful immobilization of POx_RGD on the membrane surface was confirmed by XPS and FTIR-ATR. The resulting membranes had an asymmetric microstructure, as shown by scanning electron microscopy (SEM), where the glass-cured surface was more porous and had a higher surface area then the air-cured surface. The higher porosity should support bone tissue regeneration, while the air-cured side is more suited to preventing soft tissue infiltration. The behavior of osteoblast-like cells on PLGA membranes modified with POx_RGD was compared to cell behavior on PLGA foil, non-modified PLGA membranes, or PLGA membranes modified only with POx. For this, MG-63 cells were cultured for 4, 24, and 96 h on the membranes and analyzed by metabolic activity tests, live/dead staining, and fluorescent staining of actin fibers. The results showed bone cell adhesion, proliferation, and viability to be the highest on membranes modified with POx_RGD, making them possible candidates for GTR applications in periodontology and in bone tissue engineering.

7.
Adv Healthc Mater ; 10(22): e2101327, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34541827

RESUMO

Poly(ethylene glycol) (PEG)-glycosaminoglycan (GAG) hydrogel networks are established as very versatile biomaterials. Herein, the synthetic gel component of the biohybrid materials is systematically varied by combining different poly(2-alkyl-2-oxazolines) (POx) with heparin applying a Michael-type addition crosslinking scheme: POx of gradated hydrophilicity and temperature-responsiveness provides polymer networks of distinctly different stiffness and swelling. Adjusting the mechanical properties and the GAG concentration of the gels to similar values allows for modulating the release of GAG-binding growth factors (VEGF165 and PDGF-BB) by the choice of the POx and its temperature-dependent conformation. Adsorption of fibronectin, growth of fibroblasts, and bacterial adhesion scale with the hydrophobicity of the gel-incorporated POx. In vitro hemocompatibility tests with freshly drawn human whole blood show advantages of POx-based gels compared to the PEG-based reference materials. Biohybrid POx hydrogels can therefore enable biomedical technologies requiring GAG-based materials with customized and switchable physicochemical characteristics.


Assuntos
Heparina , Hidrogéis , Materiais Biocompatíveis , Glicosaminoglicanos , Humanos , Polietilenoglicóis
8.
Artigo em Alemão | MEDLINE | ID: mdl-34143252

RESUMO

BACKGROUND: Currently, there is no comprehensive presentation of trends in oral diseases in the German general population over the last 20 years. OBJECTIVES: How did prevalences of caries, periodontitis, and tooth loss and their determinants change in Germany between 1997 and 2014? MATERIALS AND METHODS: We analysed data from 35- to 44-year-olds and 65- to 74-year-olds from the German Oral Health Studies ("Deutsche Mundgesundheitsstudien" [DMS]) III to V and of 25- to 74-year-olds from the Studies of Health in Pomerania (SHIP­0 and SHIP-Trend-0). The decayed, missing, filled teeth index (DMFT), the number of sound teeth, the community periodontal index (CPI), and data on tooth count and edentulism were analysed. RESULTS: Regarding determinants, an increase in subjects with high school education, a slight decrease in smokers, and an increase in better oral hygiene patterns was observed in both studies. In 35- to 44-year-olds, the number of sound teeth increased from 11.9 in DMS III to 16.8 in DMS V, while in 65- to 74-year-olds the number of sound teeth increased by 5.9. A similar trend was observed in SHIP. In DMS, the prevalence of the highest CPI score of 4 decreased from 9.3% to 3.5% in 35- to 44-year-olds; in 65- to 74-year-olds, the 2014 prevalence was at the same level as in 1997 (10.5% and 9.8%). In parallel, the percentage of edentulous 65- to 74-year-olds halved in both studies. The number of teeth increased across all age strata. CONCLUSIONS: DMS and SHIP consistently showed an increase in the number of healthy teeth free of fillings, a slight reduction of subjects with a CPI score of 4, more tooth retention, and less edentulism. Because of more tooth retention and current demographic changes, higher periodontal treatment needs might be expected for the future.


Assuntos
Cárie Dentária , Perda de Dente , Estudos Transversais , Índice CPO , Cárie Dentária/epidemiologia , Alemanha/epidemiologia , Humanos , Saúde Bucal , Prevalência , Perda de Dente/epidemiologia
9.
Angew Chem Int Ed Engl ; 60(24): 13621-13625, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-33751767

RESUMO

We report herein a facile and generalized approach to the modification of solid surfaces with polymer brushes under ambient conditions: filter paper-assisted surface-initiated Cu0 -mediated controlled radical polymerization (PSI-CuCRP). The polymerization solution wetted filter paper is sandwiched between a copper plate and an initiator-modified substrate, which allows the creation of a surface-initiated polymerization (SIP) "band-aid" so that everyone can perform the surface grafting selectively with good control over the quality of the polymer brushes employing low concentration and microliter amounts of the monomer solution. The versatility of this method is demonstrated by grafting different homo-, block-, and multicomponent polymer brushes by using the same activation system and reaction conditions, the polymerization process can be precisely controlled to yield uniform polymers and show high chain-end functionality which is exemplified by in situ tetra-copolymerization. The combination of photolithography and paper cutting enables to prepare arbitrary three-dimensional patterned polymer brushes on the surface.

10.
Br Dent J ; 229(7): 474-482, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33037372

RESUMO

Objectives To define an expert Delphi consensus on when to intervene in the caries process and existing carious lesions.Methods Non-systematic literature synthesis, expert Delphi consensus process and expert panel conference.Results Lesion activity, cavitation and cleansability determine intervention thresholds. Inactive lesions do not require treatment (in some cases, restorations may be placed for form, function, aesthetics); active lesions do. Non-cavitated carious lesions should be managed non- or micro-invasively, as should most cavitated lesions which are cleansable. Cavitated lesions which are not cleansable usually require minimally invasive management. In specific circumstances, mixed interventions may be applicable. Occlusally, cavitated lesions confined to enamel/non-cavitated lesions extending radiographically into deep dentine may be exceptions. Proximally, cavitation is hard to assess tactile-visually. Most lesions extending radiographically into the middle/inner third of dentine are assumed to be cavitated. Those restricted to the enamel are not cavitated. For lesions extending radiographically into the outer third of dentine, cavitation is unlikely. These lesions should be managed as if they were non-cavitated unless otherwise indicated. Individual decisions should consider factors modifying these thresholds.Conclusions Comprehensive diagnosis is the basis for systematic decision-making on when to intervene in the caries process and existing lesions.


Assuntos
Cárie Dentária , Dentina , Consenso , Cárie Dentária/terapia , Suscetibilidade à Cárie Dentária , Estética Dentária , Humanos
12.
Clin Oral Investig ; 24(11): 3997-4003, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32246279

RESUMO

OBJECTIVE: This is the second part of a report on tooth loss in Germany 1997-2030. Here, we describe trends in the prevalence of edentulism in seniors 1997-2014, assess predictive factors for edentulism, and projected it into 2030. MATERIAL AND METHODS: We used data from three waves of the cross-sectional, multi-center, nationwide representative German Oral Health Studies. Overall, 3449 seniors (65-74 years) were included (1997: 1367; 2005: 1040; 2016: 1042). Age, sex, educational level, smoking status, and the cohort were entered into age-cohort binary-logistic regression models to assess the association of predictors with edentulism and to project edentulism in 2030 via Monte Carlo simulations. RESULTS: Between 1997 and 2014, the prevalence of edentulism decreased from 24.8 to 12.4%. With each year of age, the risk of being edentate increased (by 11%, p < 0.001); it was also significantly increased in female versus male (by 40%, p = 0.001), low versus medium and high educational level (up to 257%, p < 0.001), and in former and current smokers (up to 258%, p < 0.001). We predict the prevalence of edentulism to be reduced to 4.2% in 2030. The reduction will be higher in males, never and former smokers, and those with low socio-educational level. On an absolute level and despite a growing elderly population (aged 60-80 years), the number of edentate individuals will have decreased by 3.6 million in 2030 compared with 1997. CONCLUSIONS: Edentulism in seniors has declined equitably in Germany. The decline is expected to continue until 2030. Further efforts are needed to tackle the underlying risk factors. CLINICAL RELEVANCE: This study presents trends of edentulism in Germany for a period of three decades. It provides clinically relevant data for health care planning by 2030.


Assuntos
Boca Edêntula , Perda de Dente , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Boca Edêntula/epidemiologia , Prevalência , Fatores de Risco , Perda de Dente/epidemiologia
13.
ACS Sens ; 5(2): 303-307, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32039587

RESUMO

The detection of thiocyanate (SCN-) is particularly important in industrial effluents and biological fluids because of the toxic nature of SCN-. Herein, a metal-insulator-metal (MIM) resonator for visual detection of SCN- is presented based on a poly[(2-(methacryloyloxy)ethyl) trimethylammonium chloride] (PMETAC) brush. The MIM resonator exhibits obvious color change as the concentration of SCN- changes, which can be easily distinguished by the naked eyes. In addition, the as-prepared MIM resonator also shows the advantages of good anti-interference, excellent reusability, and fast response rate. Combining the above advantages, the proposed MIM resonator may provide a broad perspective for a wide variety of visible-light applications.


Assuntos
Técnicas Biossensoriais/métodos , Tiocianatos/química , Transdutores/normas
14.
ACS Appl Mater Interfaces ; 12(8): 9797-9805, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31999093

RESUMO

Graphitic carbon nitride (gCN) has a broad range of promising applications, from energy harvesting and storage to sensing. However, most of the applications are still restricted due to gCN poor dispersibility and limited functional groups. Herein, a direct photografting of gCN using various polymer brushes with tailorable functionalities via UV photopolymerization at ambient conditions is demonstrated. The systematic study of polymer brush-functionalized gCN reveals that the polymerization did not alter the inherent structure of gCN. Compared to the pristine gCN, the gCN-polymer composites show good dispersibility in various solvents such as water, ethanol, and tetrahydrofuran (THF). Patterned polymer brushes on gCN can be realized by employing photomask and microcontact printing technology. The polymer brushes with incorporated silver nanoparticles (AgNPs) on gCN can act as a multifunctional recyclable active sensing layer for surface-enhanced Raman spectroscopy (SERS) detection and photocatalysis. This multifunctionality is shown in consecutive cycles of SERS and photocatalytic degradation processes that can be applied to in situ monitor pollutants, such as dyes or pharmaceutical waste, with high chemical sensitivity as well as to water remediation. This dual functionality provides a significant advantage to our AgNPs/polymer-gCN with regard to state-of-the-art systems reported so far that only allow SERS pollutant detection but not their decomposition. These results may provide a new methodology for the covalent functionalization of gCN and may enable new applications in the field of catalysis, biosensors, and, most interestingly, environmental remediation.

15.
ACS Macro Lett ; 9(3): 328-333, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35648544

RESUMO

A facile and universal oxygen-tolerant, capillary microfluidic-derived, controlled radical polymerization for surface structuring (gradient and patterned polymer brushes) is reported. A syringe pump and a filter paper sheet are used as capillary microfluidic to supply the reaction solution (monomer, solvent, and ligand) to a sandwich-shaped setup by placing a flat copper plate onto an ATRP initiator-modified substrate and resulting in gradient polymer brush formation with controlled thickness, steepness, and grafting area, polymers are showing the high chain-end fidelity. Two different polymer brushes (binary polymer brushes) can be simultaneously grown from both ends of the initiator modified substrate by using this method, which can be used to study the interfacial properties of different polymer brushes.

16.
Clin Oral Investig ; 24(9): 3001-3008, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31823023

RESUMO

OBJECTIVES: The intra-class correlation coefficient (ICC) is a measure of intra-subject clustering effects. A priori estimates of the ICC and the associated design effect (DE) are required for sample size estimation in clustered studies, and should be considered during their analysis, too. We aimed to determine the clustering effects of carious lesions, apical lesions, periodontal bone loss, and periodontal pocketing, assessed in clinical or radiographic examinations. METHODS: A subsample of patients (n = 175) enrolled in the fifth German Oral Health Study provided data on clinically determined carious teeth (i.e., with untreated carious lesions, WHO method) as well as teeth with periodontal pocketing (i.e., with maximum probing-pocket-depths ≥ 4 mm). A sample of panoramic radiographs (n = 85) from randomly chosen patients, examined from 2010 to 2017 at the Charité dental hospital, provided data on radiographically determined carious teeth (i.e., with lesions extending into dentine or enamel), teeth with apical lesions (determined by dentists via majority vote), and teeth with periodontal bone loss (≥ 20% of root-length). The ICC and its 95% confidence interval (95% CI) were determined. RESULTS: There were 3839 and 1961 teeth assessed in clinical and radiographic evaluations, respectively. For clinically or radiographically determined carious lesions, the ICC (95% CI) was 0.20 (0.16-0.24) or 0.19 (0.14-0.25), respectively. For clinical pocketing or radiographic bone loss, the ICC was 0.40 (0.35-0.46) or 0.30 (0.24-0.38), respectively. The lowest ICC was found for apical lesions at 0.08 (0.06-0.13). CONCLUSIONS: The ICC varied between assessment methods and conditions. Clustered trials should account for this during study planning and data analysis. CLINICAL RELEVANCE: Within the limitations of this study, and considering the risk of selection bias and the limited sample sizes of both datasets, clustering effects were substantial but varied between dental conditions. Studies not accounting for this during planning and analysis may yield misleading estimates if clustering is present.


Assuntos
Perda do Osso Alveolar , Cárie Dentária , Doenças da Boca , Dente , Perda do Osso Alveolar/diagnóstico por imagem , Análise por Conglomerados , Cárie Dentária/diagnóstico por imagem , Humanos
17.
Chemistry ; 26(12): 2749-2753, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31826315

RESUMO

Poly(2-oxazoline)s (POx) bottle-brush brushes have excellent biocompatible and lubricious properties, which are promising for the functionalization of surfaces for biomedical devices. Herein, a facile synthesis of POx is reported which is based bottle-brush brushes (BBBs) on solid substrates. Initially, backbone brushes of poly(2-isopropenyl-2-oxazoline) (PIPOx) were fabricated via surface initiated Cu0 plate-mediated controlled radical polymerization (SI-Cu0 CRP). Poly(2-methyl-2-oxazoline) (PMeOx) side chains were subsequently grafted from the PIPOx backbone via living cationic ring opening polymerization (LCROP), which result in ≈100 % increase in brush thickness (from 58 to 110 nm). The resultant BBBs shows tunable thickness up to 300 nm and high grafting density (σ) with 0.42 chains nm-2 . The synthetic procedure of POx BBBs can be further simplified by using SI-Cu0 CRP with POx molecular brush as macromonomer (Mn =536 g mol-1 , PDI=1.10), which results in BBBs surface up to 60 nm with well-defined molecular structure. Both procedures are significantly superior to the state-of-art approaches for the synthesis of POx BBBs, which are promising to design bio-functional surfaces.


Assuntos
Materiais Biocompatíveis/síntese química , Oxazóis/síntese química , Cobre/química , Estrutura Molecular , Oxazóis/química , Poliaminas/química , Polimerização , Polipropilenos/química
18.
ACS Appl Mater Interfaces ; 11(44): 41668-41675, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31623430

RESUMO

Dynamic color-changing nanomaterials have been widely investigated for applications in fields like optical sensors, wearable activity monitors, smart electronic devices, and anticounterfeiting materials due to the excellent ability to change their optical properties with external variation. Here, a simple metal-insulator-metal (MIM) trilayer Fabry-Perot resonance cavity with a poly(N-isopropylacrylamide) (PNIPAm) brush layer as a responsive element is reported as a thermal-induced colorimetric response platform. The dynamic changes of conformation and physical properties of PNIPAm brush layer in response to external signals give rise to a significant color change of the MIM Fabry-Perot resonance cavity. This MIM Fabry-Perot resonance cavity shows the advantages of dynamic color change, rapid response, good repeatability, and simple construction. Additionally, the as-prepared MIM cavity shows great potential in various applications such as color printing, multicolor indicator, and information anticounterfeiting.

19.
Clin Oral Investig ; 23(10): 3691-3703, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31444695

RESUMO

OBJECTIVES: To define an expert Delphi consensus on when to intervene in the caries process and on existing carious lesions using non- or micro-invasive, invasive/restorative or mixed interventions. METHODS: Non-systematic literature synthesis, expert Delphi consensus process and expert panel conference. RESULTS: Carious lesion activity, cavitation and cleansability determine intervention thresholds. Inactive lesions do not require treatment (in some cases, restorations will be placed for reasons of form, function and aesthetics); active lesions do. Non-cavitated carious lesions should be managed non- or micro-invasively, as should most cavitated carious lesions which are cleansable. Cavitated lesions which are not cleansable usually require invasive/restorative management, to restore form, function and aesthetics. In specific circumstances, mixed interventions may be applicable. On occlusal surfaces, cavitated lesions confined to enamel and non-cavitated lesions radiographically extending deep into dentine (middle or inner dentine third, D2/3) may be exceptions to that rule. On proximal surfaces, cavitation is hard to assess visually or by using tactile methods. Hence, radiographic lesion depth is used to determine the likelihood of cavitation. Most lesions radiographically extending into the middle or inner third of the dentine (D2/3) can be assumed to be cavitated, while those restricted to the enamel (E1/2) are not cavitated. For lesions radiographically extending into the outer third of the dentine (D1), cavitation is unlikely, and these lesions should be managed as if they were non-cavitated unless otherwise indicated. Individual decisions should consider factors modifying these thresholds. CONCLUSIONS: Comprehensive diagnostics are the basis for systematic decision-making on when to intervene in the caries process and on existing carious lesions. CLINICAL RELEVANCE: Carious lesion activity, cavitation and cleansability determine intervention thresholds. Invasive treatments should be applied restrictively and with these factors in mind.


Assuntos
Cárie Dentária/terapia , Esmalte Dentário/patologia , Dentina/patologia , Consenso , Técnica Delphi , Estética Dentária , Humanos
20.
Adv Healthc Mater ; 8(18): e1900352, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31410996

RESUMO

The shape of nanoparticles is known recently as an important design parameter influencing considerably the fate of nanoparticles with and in biological systems. Several manufacturing techniques to generate nonspherical nanoparticles as well as studies on in vitro and in vivo effects thereof have been described. However, nonspherical nanoparticle shape stability in physiological-related conditions and the impact of formulation parameters on nonspherical nanoparticle resistance still need to be investigated. To address these issues, different nanoparticle fabrication methods using biodegradable polymers are explored to produce nonspherical nanoparticles via the prevailing film-stretching method. In addition, systematic comparisons to other nanoparticle systems prepared by different manufacturing techniques and less biodegradable materials (but still commonly utilized for drug delivery and targeting) are conducted. The study evinces that the strong interplay from multiple nanoparticle properties (i.e., internal structure, Young's modulus, surface roughness, liquefaction temperature [glass transition (Tg ) or melting (Tm )], porosity, and surface hydrophobicity) is present. It is not possible to predict the nonsphericity longevity by merely one or two factor(s). The most influential features in preserving the nonsphericity of nanoparticles are existence of internal structure and low surface hydrophobicity (i.e., surface-free energy (SFE) > ≈55 mN m-1 , material-water interfacial tension <6 mN m-1 ), especially if the nanoparticles are soft (<1 GPa), rough (Rrms > 10 nm), porous (>1 m2 g-1 ), and in possession of low bulk liquefaction temperature (<100 °C). Interestingly, low surface hydrophobicity of nanoparticles can be obtained indirectly by the significant presence of residual stabilizers. Therefore, it is strongly suggested that nonsphericity of particle systems is highly dependent on surface chemistry but cannot be appraised separately from other factors. These results and reviews allot valuable guidelines for the design and manufacturing of nonspherical nanoparticles having adequate shape stability, thereby appropriate with their usage purposes. Furthermore, they can assist in understanding and explaining the possible mechanisms of nonspherical nanoparticles effectivity loss and distinctive material behavior at the nanoscale.


Assuntos
Sistemas de Liberação de Medicamentos , Nanopartículas/química , Módulo de Elasticidade , Hidrodinâmica , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas/ultraestrutura , Porosidade , Dióxido de Silício/química , Eletricidade Estática , Propriedades de Superfície
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