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1.
Dent Med Probl ; 58(3): 359-367, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34597479

RESUMO

BACKGROUND: Polyetheretherketone (PEEK) is a new material that was introduced for the fabrication of implants and their superstructure along with other available materials. It is not yet known whether the carbon fiber-reinforced polyetheretherketone (CFR­PEEK) material can be used as an implant and its superstructure in place of titanium (Ti). OBJECTIVES: The study evaluated stress distribution around CFR­PEEK implants and Ti implants with 5 different prosthetic crowns. MATERIAL AND METHODS: A three-dimensional (3D) model of a bone block was created to represent the right maxillary premolar area with a bone-level implant system with 100% osseointegration, using the Ansys Workbench software, v. 15.0. In total, 10 3D finite element analysis (FEA) models were created. The models were divided into 2 groups according to the type of implant: the CFR­PEEK group (n = 5); and the Ti group (n = 5). Each group was subdivided to imitate 5 different restorative crown materials (PEEK, zirconia, porcelain fused to metal (PFM), metal, and acrylic resin). Each implant model was loaded vertically (200 N) and obliquely (100 N). Stress distribution in the implants, the abutments, the cement layers, and the crowns was evaluated using the von Mises stress analysis. Maximum and minimum principal stress analyses were used to determine the stress generated in the bone. RESULTS: The CFR­PEEK implants bore more stress in vertical and oblique loading as compared to the Ti implants. The stress generated in the bone with the CFR­PEEK implants was similar to that generated with the Ti implants under vertical loading. Under oblique loading, less stress was transferred to the bone with the CFR­PEEK implants as compared to the Ti implants, showing better adaptation of the CFR­PEEK implants to lateral stress. CONCLUSIONS: In this FEA study, the amount of stress generated within the bone in the case of the CFR­PEEK implants with different restorative crowns was smaller in comparison with the Ti implants in oblique loading. This could help reduce lateral stress on implants as well as crestal bone loss.


Assuntos
Implantes Dentários , Titânio , Benzofenonas , Coroas , Análise do Estresse Dentário , Análise de Elementos Finitos , Humanos , Polímeros , Estresse Mecânico
2.
J Int Med Res ; 49(9): 3000605211041265, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34551599

RESUMO

OBJECTIVE: To compare the sternal fixation effect of a polyetheretherketone (PEEK) cable product and stainless steel wire after median sternotomy. METHODS: A multicentre retrospective clinical trial was conducted in patients that underwent median sternotomy for a range of surgical reasons. The sternum was fixed using PEEK sternal cables in the experimental group and stainless steel wires in the control group. The general patient state, product manoeuvrability, bone and wound healing state and blood test results were evaluated at seven visits during the preoperative, surgical and follow-up periods. RESULTS: A total of 108 patients (54 in each group) were included in the analysis at the final 180-day follow-up. The sternum was successfully closed using PEEK cables or steel wires in all patients and all healed well. No pathological changes were found on the X-ray imaging. Computed tomography imaging confirmed ideal fracture healing. No significant difference was found between the experimental group and the control group in outcomes. CONCLUSION: PEEK cables are easy to implant and show desirable effectiveness in sternal fixation without any observed side-effects.


Assuntos
Aço Inoxidável , Esternotomia , Benzofenonas , Fios Ortopédicos , Humanos , Polímeros , Estudos Retrospectivos , Esterno/diagnóstico por imagem , Esterno/cirurgia
3.
J Cataract Refract Surg ; 47(9): 1115-1121, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34468447

RESUMO

PURPOSE: To evaluate aqueous pharmacokinetics of topical bromfenac 0.09% and compare clinical outcomes of once- and twice-daily dosing in phacoemulsification. SETTING: Dr. R.P. Center for Ophthalmic Sciences, AIIMS, New Delhi, India. DESIGN: Prospective interventional study. METHODS: In phase I, single-drop aqueous pharmacokinetics of topical bromfenac was estimated at 15 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, 12 hours, and 24 hours using liquid chromatography mass spectrometry in 60 eyes. In phase II, 45 eyes undergoing phacoemulsification were enrolled: group I (control, n = 15), group II (once-daily bromfenac, n = 14), and group III (twice-daily bromfenac, n = 16). Intraoperative pupillary miosis, postoperative anterior chamber (AC) flare, Summed Ocular Inflammation Score (SOIS), central macular thickness (CMT), and pain scores were assessed. Follow-up was performed at 1 day, 7 days, 28 days, and 90 days postoperatively. RESULTS: Half-life of topical bromfenac was 3.6 hours, mean residence time 5.5 hours, and peak concentration (63.73 ng/mL) achieved after 2 hours. Aqueous concentration was more than inhibitory concentration (IC50) at 12 hours but not at 24 hours. Cumulative effect was observed with repeated dosing with aqueous levels more than IC50 in once-daily and twice-daily groups at 5 days. Significant intraoperative miosis was observed in group I. Pain score, AC flare, and SOIS were significantly more in group I (P < .001) and comparable in groups II and III at all timepoints. CMT was comparable in all groups; no case developed cystoid macular edema. CONCLUSIONS: Single-dose topical bromfenac did not maintain therapeutic aqueous concentration over 24 hours; however, cumulative effect was observed with repeated dosing. Clinical efficacy of once-daily and twice-daily dosing was comparable.


Assuntos
Anti-Inflamatórios não Esteroides , Bromobenzenos , Benzofenonas , Humanos , Soluções Oftálmicas , Estudos Prospectivos , Resultado do Tratamento
4.
Neurol India ; 69(4): 966-972, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34507423

RESUMO

Background: Posterolateral decompression and debridement in patients with TB spine led to defect in the anterior column which makes the spinal column unstable, thus making anterior column reconstruction an important step in surgical management. Objective: Through the study, authors sought to answer the following questions: 1) What are the differences in clinical outcomes between patients with TB spine undergoing anterior column reconstruction using titanium mesh cage versus PEEK cage? 2) What are the differences in radiological outcomes between these two groups of patients? Methods: This is a retrospective comparative study including patients with TB spine undergoing surgical management. The included subjects were divided into groups A and B depending on the implantation of PEEK or titanium mesh cage respectively for anterior column reconstruction. Outcome criteria analyzed included clinical criteria like VAS and ODI scores, radiological criteria like kyphosis correction, loss of kyphosis at follow-up, cage subsidence, and bony fusion on a 2D CT scan. Results: The study population included 14 patients in Group A and 15 patients in Group B. Improvement in VAS and ODI scores was comparable between groups. There was no significant difference in radiological outcome measures between the two groups, however, two patients from group B showed implant-related complications needing revision. All patients showed good bony fusion at the final follow-up. Conclusion: PEEK and titanium cages have comparable clinico-radiological outcomes for anterior column reconstruction in patients with active TB spine. Its advantages for being radiolucent and its ease of use may make it a choice of implant.


Assuntos
Fusão Vertebral , Tuberculose da Coluna Vertebral , Benzofenonas , Humanos , Vértebras Lombares , Polímeros , Estudos Retrospectivos , Titânio , Resultado do Tratamento , Tuberculose da Coluna Vertebral/diagnóstico por imagem , Tuberculose da Coluna Vertebral/cirurgia
5.
Mater Sci Eng C Mater Biol Appl ; 128: 112333, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474884

RESUMO

Polyetheretherketone (PEEK) was widely applied into fabricating of orthopaedic implants, benefitting its excellent biocompatibility and similar mechanical properties to native bones. However, the inertness of PEEK hinders its integration with the surrounding bone tissue. Here PEEK scaffolds with a series of hydroxyapatite (HA) contents in gradient were manufactured via fused filament fabrication (FFF) 3D printing techniques. The influence of the pore size, HA content and printing direction on the mechanical properties of the PEEK/HA scaffolds was systematically evaluated. By adjusting the pore size and HA contents, the elastic modulus of the PEEK/HA scaffolds can be widely tuned in the range of 624.7-50.6 MPa, similar to the variation range of natural cancellous bone. Meanwhile, the scaffolds exhibited higher Young's modulus and lower compressive strength along Z printing direction. The mapping relationship among geometric parameters, HA content, printing direction and mechanical properties was established, which gave more accurate predictions and controllability of the modulus and strength of scaffolds. The PEEK/HA scaffolds with the micro-structured surface could promote cell attachment and mineralization in vitro. Therefore, the FFF-printed PEEK/HA composites scaffolds can be a good candidate for bone grafting and tissue engineering.


Assuntos
Durapatita , Cetonas , Benzofenonas , Polietilenoglicóis , Polímeros , Porosidade , Impressão Tridimensional , Tecidos Suporte
6.
Zhongguo Zhong Yao Za Zhi ; 46(15): 3859-3864, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34472260

RESUMO

This study explored the chemical constituents of the aerial part of Hypericum curvisepalum. Sixteen compounds were isolated from the 95% ethanol extract of H. curvisepalum with various chromatographic techniques, including a new prenylated phenyl polyketide, mysorenone D(1). Other compounds were mysorenone-A(2), mysorenone-C(3), mysorenone-B(4), peplidiforone A(5), 4-methoxy-3-(2-methylbut-3-en-2-yl)-6-phenyl-2H-pyran-2-one(6), hyperenone-A(7), 4-(3,3-dimethylallyl)oxy-6-phenyl-α-pyrone(8), peplidiforone B(9), elegaphenone(10), hypercohin A(11), hyperisampsin G(12), spathulenol(13), quercetin(14), ß-sitosterol(15), and ß-amyrin(16).


Assuntos
Hypericum , Benzofenonas , Quercetina
7.
Sci Total Environ ; 798: 149275, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34333440

RESUMO

Parabens, benzophenone (BP)-type UV filters, triclosan (TCS), and triclocarban (TCC) are commonly used in personal care products. Human exposure to these compounds has received increasing concern because of their adverse health effects. However, the levels of these chemicals in paired urine and indoor samples have never been simultaneously measured. In this work, eight parabens, eight BP-type UV filters, TCS, and TCC were measured in paired urine and indoor dust samples collected from university students and their dormitories in South China. The target analytes were commonly measured in urine (71%-100%) and indoor dust (30%-98%), with median concentrations ranging from 0.16 ng/mL to 19.3 ng/mL in urine and from <0.01 ng/g to 3700 ng/g in indoor dust samples. Females had high levels of most of these target compounds, and gender-related differences were found in the levels of most target analytes. Positive correlations were found in the levels of methylparaben, ethyl paraben, benzophenone-3, and TCS between urine and indoor dust samples. This finding suggested that indoor dust is an important source for human exposure to these compounds. The estimated daily intake (EDI) of these analytes in paired samples was also evaluated. The median EDI-urine values of target analytes varied in the range of 4.02-59,280 ng/kg bw/day. Females had higher median EDI-urine values for most of target analytes than males. In addition, the median EDI-indoor dust values of most target analytes in dust from female dormitories were higher than those in dust from male dormitories. Indoor dust ingestion only had minor contribution (<0.5%) to the total exposure. To the best of the authors' knowledge, this study is the first to simultaneously analyze the concentrations of parabens, BP-type UV filters, TCS, and TCC in the paired urine and indoor samples from university students in South China.


Assuntos
Triclosan , Benzofenonas , Carbanilidas , China , Poeira/análise , Feminino , Humanos , Masculino , Parabenos/análise , Estudantes , Triclosan/análise , Universidades
8.
Int J Artif Organs ; 44(10): 748-755, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34387526

RESUMO

Anterior cervical discectomy with fusion (ACDF) is the common method to treat the cervical disc degeneration. The most serious problems in the fusion cages are adjacent disc degeneration, loss of lordosis, pain, subsidence, and migration of the cage. The objective of our work is to develop the three-dimensional finite element (FE) model from C3-C6 and virtually implant a designed S-type dynamic cage at C4-C5 segment of the model. The dynamic cage design will provide mobility in the early stage after ACDF surgery. Titanium (Ti) and PEEK (polyether ether ketone) were used as the material property for the cages. We applied the physiological motions at different loads from 0.5, 1, 1.5, 2.0 Nm to evaluate the dynamic cage design and the biomechanical performances of the designed S-type dynamic cage. It was observed that in all the loading condition the range of motion in the adjacent level was maintained and the maximum stress at the adjacent disc was reduced. The clinical significance of the S-type dynamic cage is better stress profile at the fusion level and adjacent segments which translates into higher rate of fusion, lower risk of cage subsidence, lower risk of adjacent segment degeneration, and good mechanical stability.


Assuntos
Discotomia , Titânio , Benzofenonas , Fenômenos Biomecânicos , Vértebras Cervicais/cirurgia , Análise de Elementos Finitos , Cetonas , Polímeros , Amplitude de Movimento Articular
9.
J Indian Prosthodont Soc ; 21(3): 240-248, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34380810

RESUMO

Aim: The aim of the present study was to clinically assess the performance of BioHPP PEEK material when used for inlay restoration and to compare it with widely used zirconia inlays. This clinical study was undertaken to evaluate their performance in terms of retention, colour matching, marginal discoloration, marginal adaptation, secondary caries, surface texture, wear-anatomic form, postoperative sensitivity and fracture resistance using the modified Ryge's criteria. Settings and Design: In vivo - prospective clinical study. Material and Methods: A total of 40 patients were selected based on inclusion and exclusion criteria requiring inlays. The patients were further divided in two groups: Group A - Consisted of 20 permanent maxillary and mandibular carious posterior teeth restored with BioHPP PEEK inlays and Group B - Consisted of 20 permanent maxillary and mandibular carious posterior teeth restored with CAD/CAM zirconia inlays (sintered monolithic zirconia, Zolid, Amann Girrbach AG, Koblach, Austria). Two prosthodontists, who were blinded to the study groups, evaluated the restorations. In cases of widely different scores, the observers re-evaluated the restorations and reached a consensus. Restorations were evaluated at the end of 1 week (base line), 3 months, 6 months, and 12 months, using modified Ryge's criteria. Statistical Analysis Used: Chi- square' test, 'Fisher's exact' test and 'z' test. Results: 90% of the BioHPP PEEK inlays were rated satisfactory in comparison to 95% of zirconia inlays. Sensitivity score was 10% in BioHPP PEEK inlays and 15% in zirconia inlays. No significant difference was encountered with other parameters in this study. Conclusion: The BioHPP PEEK when used as indirect aesthetic restorations was found to be satisfactory with relatively low rate of fracture over an observation period of one year in comparison to zirconia inlays in posterior teeth. The BioHPP PEEK can be a suitable alternative with high level of accuracy in terms of retention, marginal quality and aesthetics.


Assuntos
Desenho Assistido por Computador , Cetonas , Benzofenonas , Humanos , Polímeros , Estudos Prospectivos , Zircônio
10.
J Indian Prosthodont Soc ; 21(3): 295-303, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34380818

RESUMO

Aims: The purpose of this study is to compare and evaluate the failure modes and load-bearing capacity of different surface-treated polyether ether ketone (PEEK) copings when veneered with lithium di-silicate with that of PEEK veneered with composite. Settings and Design: In vitro; comparative study. Materials and Methods: Congruently anatomically shaped single unit PEEK copings (n = 40) were fabricated by scanning a prepared typodont tooth. The PEEK copings were subdivided among four groups (n = 10/group). Among all, one group of PEEK coping was veneered with Urethane dimethacrylate (UDMA)-based composite and other groups were veneered with lithium-di-silicate after different surface treatment on peek copings, i.e., (i) composite veneered PEEK fixed dental prosthesis (FDP) (control group: Group PC), (ii) lithium di-silicate veneered PEEK FDP (no surface treatment: Group PCeN), (iii) lithium di-silicate veneered PEEK FDP (sandblasting with 50 µm alumina: Group PCeS), and (iv) lithium di-silicate veneered PEEK FDP (chemical etching with 98% sulfuric acid: Group PCeE). The load-bearing capacity of all specimens was assessed using a universal test machine. All the samples were loaded till the cracking point and load at that point and failure modes were noted down. Statistical Analysis Used: One-way ANOVA and post hoc Tukey tests. Results: The highest load-bearing capacity was recorded for lithium di-silicate veneered PEEK copings which were chemically etched with 98% sulfuric acid (Group PCeE: 1040.25 ± 77.46) followed by Group PCeS (1017.20 ± 53.70), then Group PC (965 ± 51.57) and least was for Group PCeN (933 ± 97.54). There was a significant reduction in mean load-bearing capacity in Group PCeN (P < 0.05). Conclusions: Veneering of PEEK with pressed lithium di-silicate seems to be a viable clinical option in terms of adequate load-bearing capacity. Lithium di-silicate veneered PEEK FDPs were successful against physiological occlusal forces and are a suitable material for FDPs.


Assuntos
Cetonas , Lítio , Adaptação Psicológica , Benzofenonas , Éteres , Polímeros , Silicatos , Suporte de Carga
11.
Int J Mol Sci ; 22(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34445159

RESUMO

Polyetheretherketone (PEEK), due to its excellent mechanical and physico-chemical parameters, is an attractive substitute for hard tissues in orthopedic applications. However, PEEK is hydrophobic and lacks surface-active functional groups promoting cell adhesion. Therefore, the PEEK surface must be modified in order to improve its cytocompatibility. In this work, extreme ultraviolet (EUV) radiation and two low-temperature, EUV induced, oxygen and nitrogen plasmas were used for surface modification of polyetheretherketone. Polymer samples were irradiated with 100, 150, and 200 pulses at a 10 Hz repetition rate. The physical and chemical properties of EUV and plasma modified PEEK surfaces, such as changes of the surface topography, chemical composition, and wettability, were examined using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and goniometry. The human osteoblast-like MG63 cells were used for the analysis of cell viability and cell adhesion on all modified PEEK surfaces. EUV radiation and two types of plasma treatment led to significant changes in surface topography of PEEK, increasing surface roughness and formation of conical structures. Additionally, significant changes in the chemical composition were found and were manifested with the appearance of new functional groups, incorporation of nitrogen atoms up to ~12.3 at.% (when modified in the presence of nitrogen), and doubling the oxygen content up to ~25.7 at.% (when modified in the presence of oxygen), compared to non-modified PEEK. All chemically and physically changed surfaces demonstrated cyto-compatible and non-cytotoxic properties, an enhancement of MG63 cell adhesion was also observed.


Assuntos
Benzofenonas/química , Materiais Biocompatíveis/química , Nitrogênio/química , Osteoblastos/citologia , Oxigênio/química , Gases em Plasma/química , Polímeros/química , Adesão Celular , Linhagem Celular , Humanos , Propriedades de Superfície , Raios Ultravioleta
12.
Int J Mol Sci ; 22(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34445228

RESUMO

Recent advancements in medical imaging, virtual surgical planning (VSP), and three-dimensional (3D) printing have potentially changed how today's craniomaxillofacial surgeons use patient information for customized treatments. Over the years, polyetheretherketone (PEEK) has emerged as the biomaterial of choice to reconstruct craniofacial defects. With advancements in additive manufacturing (AM) systems, prospects for the point-of-care (POC) 3D printing of PEEK patient-specific implants (PSIs) have emerged. Consequently, investigating the clinical reliability of POC-manufactured PEEK implants has become a necessary endeavor. Therefore, this paper aims to provide a quantitative assessment of POC-manufactured, 3D-printed PEEK PSIs for cranial reconstruction through characterization of the geometrical, morphological, and biomechanical aspects of the in-hospital 3D-printed PEEK cranial implants. The study results revealed that the printed customized cranial implants had high dimensional accuracy and repeatability, displaying clinically acceptable morphologic similarity concerning fit and contours continuity. From a biomechanical standpoint, it was noticed that the tested implants had variable peak load values with discrete fracture patterns and failed at a mean (SD) peak load of 798.38 ± 211.45 N. In conclusion, the results of this preclinical study are in line with cranial implant expectations; however, specific attributes have scope for further improvements.


Assuntos
Benzofenonas , Sistemas Automatizados de Assistência Junto ao Leito , Polímeros , Impressão Tridimensional , Próteses e Implantes , Crânio/lesões , Humanos , Procedimentos Cirúrgicos Reconstrutivos
13.
Artigo em Inglês | MEDLINE | ID: mdl-34444439

RESUMO

Emerging microcontaminants benzophenone (BP), benzophenone-3 (BP-3) and caffeine (CF) are widely used anthropogenic markers from a group of pharmaceuticals and personal care products. They have different logD values and charges at neutral pH (2.96 neutral for BP; 3.65 negative and neutral for BP-3; 0.28 and neutral for CF). The goal of this study was to assess the efficacy of coagulation/flocculation/sedimentation (C/F/S), adsorption onto two types of powdered activated carbon (PAC)/sedimentation (PAC/S) and the combination of these two processes in different dosing sequences (PAC/C/F/S) and with/without ultrafiltration (powdered activated carbon/ultrafiltration-PAC/UF, coagulation/UF-CoA/UF) for the removal of selected micropollutants from river water. It was shown that the removal efficiency of benzophenones by coagulation depends on the season, while CF was moderately removed (40-70%). The removal of neutral BP by two PACs unexpectedly differed (near 40% and ˃93%), while the removal of BP-3 was excellent (>95%). PACs were not efficient for the removal of hydrophilic CF. Combined PAC/C/F/S yielded excellent removal for BP and BP-3 regardless of PAC type only when the PAC addition was followed by C/F/S, while C/F/S efficiency for CF diminished. The combination of UF with PAC or coagulant showed also high efficacy for benzophenones, but was negligible for CF removal.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Benzofenonas , Cafeína , Carvão Vegetal , Membranas Artificiais , Rios , Ultrafiltração , Poluentes Químicos da Água/análise
14.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(4): 758-763, 2021 Aug 18.
Artigo em Chinês | MEDLINE | ID: mdl-34393241

RESUMO

OBJECTIVE: To develop dexamethasone plus minocycline-loaded liposomes (Dex/Mino liposomes) and apply them to improve bioinert polyetheretherketone (PEEK) surface, which could prevent post-operative bacterial contamination, enhance ossification for physiologic osseointegration, and finally reduce implant failure rates. METHODS: Dex/Mino liposomes were covalently grafted onto the PEEK surface using polydopamine (pDA) coating as a medium. Confocal laser scanning microscopy was used to confirm the binding of fluorescently labeled liposomes onto the PEEK substrate, and a microplate reader was used to semiquantitatively measure the average fluorescence intensity of fluorescently labeled liposome-decorated PEEK surfaces. Moreover, the mouse subcutaneous infection model and the beagle femur implantation model were respectively conducted to verify the bioactivity of Dex/Mino liposome-modified PEEK in vivo, by means of micro computed tomography (micro-CT) and hematoxylin and eosin (HE) staining analysis. RESULTS: The qualitative and quantitative results of fluorescently labeled liposomes showed that, the red fluorescence intensity of the PEEK-pDA-lipo group was stronger than that of the PEEK-NF-lipo group (P < 0.05); the liposomes were successfully and uniformly decorated on the PEEK surfaces due to the pDA coating. After mouse subcutaneous implantation of PEEKs for 24 hours, HE staining results showed that the number of inflammatory cells in the PEEK-Dex/Mino lipo group were lower than that in the inert PEEK group (P < 0.05), indicating a lower degree of infection in the test group. These results suggested that the Mino released from the liposome-functionalized surface provided an effective bacteriostasis in vivo. After beagle femoral implantation of PEEK for 8 weeks, micro-CT results showed that the PEEK-Dex/Mino lipo group newly formed more continuous bone when compared with the inert PEEK group; HE staining results showed that more new bones were formed in the PEEK-Dex/Mino lipo group than in the inert PEEK group, which were firmly bonded to the functionalized PEEK surface and extended along the PEEK interface. These results suggested that the Dex released from the liposome-functionalized surface induced effective bone regeneration in vivo. CONCLUSION: Dex/Mino liposome modification enhanced the bioactivity of inert PEEK, the functionalized PEEK with enhanced antibacterial and osseointegrative capacity has great potential as an orthopedic/dental implant material for clinical application.


Assuntos
Lipossomos , Osseointegração , Animais , Benzofenonas , Cães , Cetonas , Camundongos , Polietilenoglicóis , Polímeros , Propriedades de Superfície , Microtomografia por Raio-X
15.
Eur Spine J ; 30(8): 2377-2384, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34215921

RESUMO

PURPOSE: This study aims to compare the early subsidence rate (6-12 months) of standalone novel 3D-printed titanium (Ti) versus polyetheretherketone (PEEK) interbody cages after lateral lumbar interbody fusion (LLIF). METHOD: A retrospective study of 113 patients (186 levels) who underwent LLIF surgery with Ti or PEEK cages was conducted. Early subsidence was measured in each treated level using the Marchi et al. classification in radiographs or CT scans acquired at 6-12 months follow-up. Multivariate logistic regression analyses with generalized mixed models, setting subsidence as the outcome variable and including cage type (Ti vs PEEK) as well as significant and trending variables (p < 0.10) in univariate analyses, were conducted. RESULTS: In total, 51 female and 62 male patients were analyzed. The median [IQR] age at surgery was 60.0 [51.0-70.0] years. Of the 186 levels, 119 levels were treated using PEEK and 67 levels with Ti cages. The overall subsidence rate for Grades I-III was significantly less in the Ti versus the PEEK group (p = 0.003). For high-grade subsidence (Grade II or III), Ti cages also demonstrated a subsidence rate (3.0%) that was significantly less compared to PEEK cages (18.5%) (p = 0.002). Multivariate analysis showed that patients treated with Ti cages were less likely to develop severe subsidence compared to those treated with PEEK (OR = 0.05, 95% CI = 0.01, 0.30) (p = 0.001). CONCLUSION: Our study demonstrated that 3D-printed novel Ti cages had a significantly lower early subsidence rate compared to PEEK cages in standalone LLIF patients.


Assuntos
Fusão Vertebral , Titânio , Benzofenonas , Feminino , Humanos , Cetonas , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Masculino , Polietilenoglicóis , Polímeros , Impressão Tridimensional , Estudos Retrospectivos
16.
Sci Total Environ ; 796: 148666, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34273823

RESUMO

Coral reefs are impacted by a variety of anthropogenic stressors including inputs of chemical contaminants. Although data is currently limited, sunscreens containing ultraviolet (UV) filters have recently been suggested as an emerging class of chemical contaminants. To provide further data on the toxicity of the UV filter oxybenzone (benzophenone-3 or BP-3) to corals, we conducted three independent acute toxicity tests exposing the colonial stony coral Galaxea fascicularis to BP-3 (0.31 to 10 mg/L nominal concentrations). Assessments included daily analytical verification of the exposure concentrations, calculation of the lethal concentration to result in 50% mortality (LC50) and numerous biological endpoints to further investigate the potential impact to both the coral and symbiont. LC50s for the three tests were similar and averaged 6.53 ± 0.47 mg/L nominal concentration BP-3 (4.45 mg/L measured dissolved BP-3). BP-3 did not initiate coral bleaching or show a significant loss of symbionts from the coral tissue in this species as reductions in measurements used for bleaching (i.e. visual color, color saturation and photosynthetic pigment concentrations) were only seen concurrently with tissue loss (i.e. at ≥2.5 mg/L nominal concentration BP-3). Polyp retraction, the most sensitive endpoint of this test, was seen to be a sub-lethal behavioral response to BP-3 exposure. Using the calculated LC50 with measured concentrations from a high-quality UV filter monitoring study in Hawaii, a preliminary, conservative risk quotient for BP-3 was calculated at 0.032. These results suggest that BP-3 likely does not pose an acute risk of mortality to G. fascicularis and additional testing is required to determine sublethal impacts of BP-3 under environmentally relevant concentrations and longer-term chronic exposures. This study highlights complications in conducting toxicity tests with organic UV filters including under-estimations of exposure concentrations and provides recommendations to improve these methods for better comparisons between studies.


Assuntos
Antozoários , Poluentes Químicos da Água , Animais , Benzofenonas , Recifes de Corais , Protetores Solares/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
17.
J Mech Behav Biomed Mater ; 122: 104659, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34229171

RESUMO

In this work, graphene oxide/carbon fibers/polyetheretherketone (GO/CF/PEEK) composite coatings on Ti-6Al-4V (TC4) alloy were fabricated by electrostatic powder spraying method. The coatings with 0.02 wt% GO and 25 wt% CF were made to improve the wear resistance, cytocompatibility and antibacterial properties of the TC4 as orthopedic/dental implants. The physicochemical properties involving coating thickness, Vickers hardness, micromorphology, phase structures and contact angles were investigated. The results indicated that the GO/CF/PEEK coatings can significantly decrease the coefficient of friction (COF) (from 0.433 ± 0.017 to 0.085 ± 0.008) and enhance the wear resistance of TC4 alloy during the wet friction process in sliding contact with a Si3N4 ball. The results showed that few scratches appeared on the GO/CF/PEEK coating. As the in vitro cytotoxicity test by murine fibroblast L929 cells shown, the GO/CF/PEEK coating revealed good cytocompatibility. More importantly, GO/CF/PEEK coating exhibited excellent suppression toward Staphylococcus aureus (S. aureus) owing to the antibacterial nature of GO. Therefore, the GO/CF/PEEK composite coated TC4 could be considered as a prospective orthopedic/dental implant material for bone tissue engineering.


Assuntos
Implantes Dentários , Ligas , Animais , Antibacterianos/farmacologia , Benzofenonas , Fibra de Carbono , Grafite , Teste de Materiais , Camundongos , Polímeros , Estudos Prospectivos , Staphylococcus aureus , Propriedades de Superfície , Titânio
18.
Chem Biodivers ; 18(8): e2100307, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34086414

RESUMO

Brazilian green and red propolis stand out as commercial products for different medical applications. In this article, we report the antimicrobial activities of the hydroalcoholic extracts of green (EGP) and red (ERP) propolis, as well as guttiferone E plus xanthochymol (8) and oblongifolin B (9) from red propolis, against multidrug-resistant bacteria (MDRB). We undertook the minimal inhibitory (MIC) and bactericidal (MBC) concentrations, inhibition of biofilm formation (MICB50 ), catalase, coagulase, DNase, lipase, and hemolysin assays, along with molecular docking simulations. ERP was more effective by displaying MIC and MBC values <100 µg mL-1 . Compounds 8 and 9 displayed the lowest MIC values (0.98 to 31.25 µg mL-1 ) against all tested Gram-positive MDRB. They also inhibited the biofilm formation of S. aureus (ATCC 43300 and clinical isolate) and S. epidermidis (ATCC 14990 and clinical isolate), with MICB50 values between 1.56 and 6.25 µg mL-1 . The molecular docking results indicated that 8 and 9 might interact with the catalase's amino acids. Compounds 8 and 9 have great antimicrobial potential.


Assuntos
Anti-Infecciosos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Própole/química , Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Benzofenonas/química , Benzofenonas/isolamento & purificação , Benzofenonas/metabolismo , Benzofenonas/farmacologia , Sítios de Ligação , Biofilmes/efeitos dos fármacos , Brasil , Catalase/química , Catalase/metabolismo , Domínio Catalítico , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Própole/metabolismo , Própole/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
19.
Food Funct ; 12(14): 6432-6441, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34075995

RESUMO

Ten new polyisoprenylated benzophenone derivatives, 4,8-epi-uralione F (1), 4,8-epi-uralione G (2), uralione S (3), coccinone J (4), 6-epi-coccinone C (5), coccinone I (6), 36-hydroxy-guttiferone J (7), multiflorone I (8), garciniagifolone F (9) and 36-hydroxy-garciniagifolone F (10), were isolated from the fruits of Garcinia cambogia, along with seven known analogues. The structures of the new compounds were established based on the detailed analysis of 1D and 2D nuclear magnetic resonance (NMR) spectra and high resolution electrospray ionization mass spectrometra (HRESIMS), and their absolute configurations were determined from the electronic circular dichroism (ECD) spectra. All the isolates were tested for their inhibitory effects against nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The results indicated that compound 1 displayed a potent NO inhibitory effect with an IC50 value of 41.60 ± 0.17 µM. Furthermore, compound 1 suppressed inducible NO synthase (iNOS) expression in a dose-dependent manner through inhibiting the activation of nuclear factor-κB (NF-κB).


Assuntos
Anti-Inflamatórios/farmacologia , Benzofenonas/farmacologia , Frutas/química , Garcinia cambogia/química , Animais , Anti-Inflamatórios/química , Benzofenonas/química , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular/métodos , Lipopolissacarídeos/farmacologia , Espectroscopia de Ressonância Magnética/métodos , Camundongos , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Células RAW 264.7 , Espectrometria de Massas por Ionização por Electrospray/métodos
20.
Int J Clin Pract ; 75(9): e14440, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34096673

RESUMO

PURPOSE: This study aimed to compare the fracture resistance and fracture mode of maxillary central incisors restored with four different sizes and three different post-core systems. MATERIALS AND METHODS: One hundred and twenty maxillary incisors were endodontically treated and randomly divided into three groups (12 subgroups). Post cavities for the narrow subgroups were prepared with 1.4-mm-diameter drills in lengths of 7.5 mm (SN) and 10 mm (LN). Post cavities for the wide subgroups were prepared with 1.6-mm-diameter drills in lengths of 7.5 mm (SW) and 10 mm (LW) (n = 10). Group F was restored with glass-fibre post and composite resin core, Group P was restored with custom PEEK post-core and Group Z was restored with custom zirconia post-core. All posts were cemented with a dual-cure resin cement. Zirconia copings were cemented. Specimens were loaded on the palatal surface with a universal testing machine, and the fracture strengths of the teeth were statistically analysed using ANOVA and post hoc Tukey tests. RESULTS: Statistically significant differences existed between the fracture strengths of the post materials. The highest fracture strength was in Group F, and the lowest was in Group P. Evaluation of the fracture strengths of the post lengths and diameters demonstrated that the short-narrow group of Group Z had the lowest fracture strength (P < .05). The long-wide group of Group F showed the highest fracture resistance. In Group P, no statistically significant difference existed between the post-cores of different dimensions (P > .05). Irreparable fractures were observed mostly in Group Z, and decementation was more common in Group P. CONCLUSIONS: PEEK post-cores showed sufficient fracture strength for the anterior region, similar to the other two post-core materials. PEEK post-cores showed more decementation and repairable fractures at lower forces, while restoration failure was mostly catastrophic for glass-fibre and zirconia posts.


Assuntos
Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Dente não Vital , Benzofenonas , Éteres , Resistência à Flexão , Humanos , Cetonas , Polímeros , Zircônio
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