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1.
J Am Chem Soc ; 146(30): 20878-20890, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39016781

RESUMO

The investigation of long noncoding RNAs (lncRNAs) and RNA binding proteins (RBPs) interactions in living cell holds great significance for elucidating their critical roles in a variety of biological activities, but limited techniques are available to profile the temporal-spatial dynamic heterogeneity. Here, we introduced a molecular beacon-functionalized nanoneedle array designed for spatially resolved profiling of lncRNA-RBP interactions (Nano-SpatiaLR). A nanoneedle array modified with a molecular beacon is employed to selectively isolate specific intracellular lncRNAs and their associated RBPs without affecting cell viability. The RBPs are then in situ analyzed with a fluorescent labeled antibody and colocalized with lncRNA signals to get a quantitative measurement of their dynamic interactions. Additionally, leveraging the spatial distribution and nanoscale modality of the nanoneedle array, this technique provides the spatial heterogeneity information on cellular lncRNA-RBPs interaction at single cell resolution. In this study, we tracked the temporal-spatial interactive heterogeneity dynamics of lncRNA-RBPs interaction within living cells across different biological progresses. Our findings demonstrated that the interactions between lncRNA HOTAIR and RBPs EZH2 and LSD1 undergo significant changes in response to drug treatments, particularly in tumor cells. Moreover, these interactions become more intensified as tumor cells aggregate during the proliferation process.


Assuntos
RNA Longo não Codificante , Proteínas de Ligação a RNA , Análise de Célula Única , RNA Longo não Codificante/metabolismo , RNA Longo não Codificante/genética , Humanos , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/química , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo
2.
Biomater Sci ; 10(12): 3259-3267, 2022 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-35583002

RESUMO

Photodynamic therapy (PDT) represents a promising treatment modality for a range of cancers and other non-malignant diseases due to its non-invasive nature arising from the light-dependent activation. However, PDT has not been the first-line treatment of cancer thus far as a consequence of, among others, the lack of effective transport and activation strategies, and the undesired side effect caused by skin photosensitisation induced by the "always on" photosensitisers. To overcome this "Achilles' heel", we present herein a non-covalent approach to construct a one-component dynamic supramolecular nanophotosensitising system based on a carefully designed porphyrin. The control of the photoactivities of the resulting supramolecular fibres lies in the spatiotemporal control of the monomer-polymer equilibrium. Both the thermodynamics and kinetics of this nanosystem have been carefully studied by different techniques. Moreover, in vitro and in vivo studies have also been performed, showing that these supramolecular aggregates exhibit facile cell internalisation and progressive disassembly after being endocyted by targeted cells, leading to activation of the photosensitising units and eventually cell death and tumour eradication under photoirradiation.


Assuntos
Nanofibras , Neoplasias , Fotoquimioterapia , Porfirinas , Humanos , Neoplasias/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes , Porfirinas/farmacologia , Porfirinas/uso terapêutico
3.
Injury ; 53(4): 1552-1556, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35140028

RESUMO

BACKGROUND: Acute Achilles tendon rupture (AATR) is a common injury of the foot and ankle. So far, the optimal management of AATR remains controversial. The target of the present retrospective study was to describe a new operative technique for percutaneous repair of AATR and evaluate efficacy of the technique. METHODS: In the present study, 32 patients were enrolled with AATR treated with the percutaneous oval forceps suture-guiding method with anchor nails from Jan 2014 to Jan 2017. The operation duration and length of incision were collected. The functional outcomes were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score, Achilles tendon total rupture score (ATRS), range of motion (ROM) of the ankle and plantar flexion strength ratio at the last follow-up. The postoperative sports activity level and complications were also recorded. RESULTS: The mean operation duration and length of incision were 24.5 min and 2.0 cm. Whilst patient reported outcome questionnaires like AOFAS and ATRS showed good results, ROM of the ankle was quite low with only 16.5 degrees. Plantar flexion strength ratio was lower post surgery, as well. As for the postoperative sports activity level: 26/32 cases (81.3%) returned to former sports activity level; 4/32 cases (12.5%) showed a decline in sports activity level; 2/32 cases (6.2%) gave up on sports. The overall complication rate was 6.2%, one sural nerve damage and one fusiform thickening were found in the study. CONCLUSION: The percutaneous oval forceps suture-guiding method with anchor nails is a new considerable surgery method with adequate healing rates and an alternative to existing surgical procedures.


Assuntos
Tendão do Calcâneo , Procedimentos Ortopédicos , Tendão do Calcâneo/lesões , Tendão do Calcâneo/cirurgia , Humanos , Unhas/cirurgia , Procedimentos Ortopédicos/métodos , Estudos Retrospectivos , Ruptura/etiologia , Ruptura/cirurgia , Instrumentos Cirúrgicos , Técnicas de Sutura , Suturas , Resultado do Tratamento
4.
Chem Commun (Camb) ; 58(5): 669-672, 2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-34919102

RESUMO

A subphthalocyanine substituted with nine tetra(ethylene glycol) chains on the periphery has been synthesised. This novel amphiphilic and cone-shaped compound can self-assemble in water into spherical nanoparticles with a hydrodynamic diameter of 154 nm. These nanoparticles can be taken up readily by cancer cells and localised predominately in lysosomes where they disassemble gradually, leading to activation in fluorescence emission and, photocytotoxicity, showing IC50 values of as low as 1.2 µM.


Assuntos
Fotoquimioterapia
5.
Biomater Sci ; 10(1): 189-201, 2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-34817474

RESUMO

A series of glutathione (GSH)-responsive polydopamine (PDA) nanoparticles (NPs) were prepared using a disulfide-linked dopamine dimer as starting material, of which the size could be tuned systematically by adjusting the amount of ammonia solution used. Molecules of a phthalocyanine (Pc)-based photosensitiser and an epidermal growth factor receptor (EGFR)-targeting peptide were then sequentially immobilised on the surface of the NPs through coupling with the surface functionalities of PDA. The immobilised Pc molecules in the resulting nanosystem were photodynamically inactive due to the strong self-quenching effect and the quenching by the PDA core. Upon exposure to GSH in phosphate-buffered saline or EGFR-positive cancer cells, namely A549 and A431 cells, the NPs were disassembled through cleavage of the disulfide linkages to release the Pc molecules, thereby restoring their fluorescence emission and singlet oxygen generation. The NPs with the smallest size (ca. 200 nm in diameter) exhibited the highest cellular uptake and high photocytotoxicity with IC50 values as low as 0.05 µM based on Pc. These NPs could also accumulate and be activated in the tumour of A431 tumour-bearing nude mice, lighting up the tumour with fluorescence over a period of 72 h and completely eradicating the tumour through laser irradiation for 10 min (675 nm, 20 J cm-2). The results suggest that these biodegradable and versatile PDA-based NPs can serve as a promising nanoplatform for fabrication of advanced photosensitisers for targeted photodynamic therapy.


Assuntos
Antineoplásicos/farmacologia , Nanopartículas , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Animais , Linhagem Celular Tumoral , Glutationa , Indóis , Camundongos , Camundongos Nus , Polímeros
6.
Nanoscale ; 13(37): 15899-15915, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34522935

RESUMO

A thioketal-linked dimer of 3,4-dihydroxy-L-phenylalanine was prepared which underwent self-polymerisation in the presence of doxorubicin (Dox) in an ethanol/water (1 : 4, v/v) mixture with ammonia. The resulting Dox-encapsulated polydopamine (PDA) nanoparticles were further conjugated with molecules of a zinc(II) phthalocyanine (Pc)-based photosensitiser and a peptide containing the heptapeptide QRHKPRE sequence (labelled as QRH) that can target the epidermal growth factor receptor (EGFR) overexpressed in cancer cells. Upon internalisation into these cells through receptor-mediated endocytosis, these nanoparticles labelled as PDA-Dox-Pc-QRH were disassembled gradually via cleavage of the thioketal linkages by the intrinsic intracellular reactive oxygen species (ROS). The stacked Pc molecules were then disaggregated, resulting in activation of their photosensitising property upon irradiation. The ROS generated by the activated Pc promoted further degradation of the nanoparticles and release of Dox, thereby enhancing cell death by synergistic chemo and photodynamic therapy. Systemic injection of PDA-Dox-Pc-QRH into EGFR-overexpressed tumour-bearing nude mice led to targeted delivery to the tumour, and subsequent light irradiation caused complete tumour ablation without inducing notable toxicity.


Assuntos
Nanopartículas , Fotoquimioterapia , Animais , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Indóis , Camundongos , Camundongos Nus , Polímeros , Espécies Reativas de Oxigênio
7.
Int Immunopharmacol ; 97: 107657, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33878544

RESUMO

Osteoarthritis (OA) is a common joint disease that takes joint degeneration or aging as its pathological basis, and joint swelling, pain or dysfunction as its main clinical manifestations. Decursin (DE), the major active component isolated from Angelica gigas Nakai, has been demonstrated to possess anti-inflammatory effect in many diseases. But, the specific physiological mechanism of DE on OA is not clear yet. Therefore, the object of this study was to assess the therapeutic effect of DE on OA, and to explore its potential anti-inflammatory mechanisms. In vitro cell experiments, the inflammatory response in chondrocytes is mediated via interleukin-1ß (IL-1ß), which led to abnormal secretion of pro-inflammatory factors, such as prostaglandin E2 (PGE2), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), nitric oxide (NO) and inducible nitric oxide synthase (iNOS). These cytokines were all decreased by the preconditioning of DE in a dose-dependent form of 1, 5, and 10 µM. Moreover, DE could restrain IL-1ß-mediated inflammatory reaction and the collapse of extracellular matrix (ECM) via reducing the secretion of ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) and MMPs (matrix metalloproteinases). In short, DE restrained IL-1ß-mediated abnormal excitation of PI3K/AKT/NF-κB axis. Furthermore, molecular docking analysis showed that DE has a strong binding affinity with the inhibitory targets of PI3K. In vivo animal studies, DE treatment could helped to improve destruction of articular cartilage and decreased the serum inflammatory factor levels in an operationally induced mouse OA model. To sum up, these data obtained from the experiment indicate that DE has good prospects for the treatment of osteoarthritis.


Assuntos
Anti-Inflamatórios/farmacologia , Benzopiranos/farmacologia , Butiratos/farmacologia , Osteoartrite/tratamento farmacológico , Animais , Anti-Inflamatórios/uso terapêutico , Benzopiranos/uso terapêutico , Butiratos/uso terapêutico , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/imunologia , Cartilagem Articular/patologia , Progressão da Doença , Avaliação Pré-Clínica de Medicamentos , Humanos , Interleucina-1beta/metabolismo , Masculino , Camundongos , Simulação de Acoplamento Molecular , NF-kappa B/metabolismo , Osteoartrite/imunologia , Osteoartrite/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia
8.
Nanoscale ; 13(13): 6499-6512, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33885529

RESUMO

A novel nanosystem of polydopamine-coated gold nanorods (AuNR@PDA) immobilised with molecules of hairpin DNA-conjugated distyryl boron dipyrromethene (DSBDP) was designed and fabricated for detection of microRNA-21 (miR-21). By using this oncogenic stimulus, the photodynamic effect of the DSBDP-based photosensitiser was also activated. In the presence of miR-21, the fluorescence intensity of the nanosystem was increased due to the dissociation of the conjugate from AuNR@PDA upon hybridisation. The intracellular fluorescence intensity triggered by intracellular miR-21 was in the order: MCF-7 > HeLa > HEK-293, which was in accordance with their miR-21 expression levels. The specificity was demonstrated by comparing the results with those of an analogue with a scrambled DNA sequence. The nanosystem could also result in miR-21-mediated photodynamic eradication of miR-21-overexpressed MCF-7 cells. After intravenous injection of the nanosystem into HeLa tumour-bearing nude mice, the fluorescence intensity of the tumour was increased over 24 h and was about 3-fold stronger than that of the scrambled analogue. Upon irradiation, the nanosystem could also greatly reduce the size of the tumour without causing significant tissue damage in the major organs. The overall results showed that this nanoplatform can serve as a specific and potent theranostic agent for simultaneous miR-21 detection and miR-21-mediated photodynamic therapy.


Assuntos
MicroRNAs , Nanotubos , Fotoquimioterapia , Animais , Boro , DNA , Ouro , Células HEK293 , Humanos , Indóis , Camundongos , Camundongos Nus , MicroRNAs/genética , Polímeros , Porfobilinogênio/análogos & derivados
9.
J Orthop Sci ; 26(4): 636-643, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32798112

RESUMO

BACKGROUND: Percutaneous reduction, cannulated screw fixation and calcium sulfate cement grafting (PR + CSC) for treatment of displaced and intra-articular calcaneal fractures (DIACFs) is a difficult technique, because the minimally invasive treatment has limited exposure and cannot be used to reduce articular surface under direct vision. The goal of this study was to apply 3D printing technology to preoperative planning and surgery of DIACFs, and to evaluate its effectiveness, feasibility and safety in fracture repair. METHODS: We enrolled 81 patients with DIACFs in the study from August 2015 to August 2017. Patients with DIACFs in our hospital were randomly divided into the 3D printing group (40 cases) and the conventional group (41 cases). The operation duration, blood loss volume and the number of fluoroscopy were compared. Radiological results were evaluated using radiographs and functional results were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score. The complications were also assessed. In addition, we made a questionnaire to verify the usefulness of the 3D printed model for both doctors and patients. RESULTS: The operation duration, blood loss volume and the number of fluoroscopy in 3D printing group were significantly less than that in the conventional group. Besides, 3D printing group achieved significantly better radiological results than conventional group both postoperatively and at the final follow-up except the calcaneal width at the final follow-up. The AOFAS score in the 3D printing group was significantly higher than that in the conventional group. In addition, the questionnaire from doctors and patients exhibited high scores of overall satisfaction of the 3D printed models. As for complications, there was no significant difference among the two groups. CONCLUSION: This study suggested the clinical feasibility of PR + CSC assisted by 3D printing technology in the treatment of DIACFs. LEVEL OF EVIDENCE: II.


Assuntos
Calcâneo , Fraturas Ósseas , Fraturas Intra-Articulares , Parafusos Ósseos , Calcâneo/diagnóstico por imagem , Calcâneo/cirurgia , Sulfato de Cálcio , Fixação Interna de Fraturas , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Humanos , Fraturas Intra-Articulares/diagnóstico por imagem , Fraturas Intra-Articulares/cirurgia , Impressão Tridimensional , Resultado do Tratamento
10.
Biochemistry ; 60(13): 1019-1030, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33169977

RESUMO

Designing nanoparticles (NPs) with desirable cell type-specific exocytosis properties, say promoting their exocytosis from scavenging cell types (e.g., macrophages and endothelial cells) or suppressing their exocytosis from target disease cell types (e.g., cancer cells), improves the application of nanomedicines. However, the design parameters available for tuning the exocytosis of NPs remain scarce in the "nano-cell" literature. Here, we demonstrate that surface modification of NPs with hydrocarbyl functional groups, commonly found in biomolecules and NP-based drug carriers, is a critical parameter for tuning the exocytosis of NPs from RAW264.7 macrophages, C166 endothelial cells, and HeLa epithelial cancer cells. To exclude the effect of hydrophobicity, we prepare a collection of hydrophilic NPs that bear a gold NP (AuNP) core, a dense polyethylene glycol (PEG) shell, and different types of hydrocarbyl groups (X) that are attached to the distal end of the PEG strands (termed "Au@PEG-X NPs"). For all three cell types tested, modification of NPs with straight-chain dodecane leads to a >10-fold increase in the level of cellular uptake, drastically higher than those of all other types of X tested. However, the probability of exocytosis of NPs significantly depends on the types of cell and X. Notably, NPs modified with cyclododecanes are most likely to be exocytosed by RAW264.7 and C166 cells (but not HeLa cells), accompanied by the release of intralumenal vesicles to the extracellular milieu. These data suggest a reductionist approach for rationally assembling bionanomaterials for nanomedicine applications by using hydrocarbyl functional groups as building blocks.


Assuntos
Exocitose , Nanopartículas/química , Animais , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Células Endoteliais/metabolismo , Ouro/química , Células HeLa , Humanos , Nanopartículas Metálicas/química , Camundongos , Tamanho da Partícula , Polietilenoglicóis/química , Células RAW 264.7 , Propriedades de Superfície
11.
J Foot Ankle Surg ; 59(6): 1209-1214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32950372

RESUMO

Flexible flatfoot is a common deformity in the pediatric population and can cause a range of symptoms and reduce the quality of life. Subtalararthroereisis may be appropriate for pediatric population whose conservative management had failed to relief their symptoms typically for at least 6 months. Subtalararthroereisis has been developed for a long time, but the use of interference screw for the treatment of pediatric flexible flatfoot has not been reported. From January, 2016 to June, 2017, we operated on 21 children (39 feet) between the ages of 8 and 14 years. The clinical assessment was based on the American Orthopedic Foot and Ankle Society (AOFAS) hind-foot scale and the Chippaux-Smirak Index (CSI) measurements. And the anatomical parameters assessment was based on the radiographs and photographs. The postoperative AOFAS scores and CSI measurements were improved compared with preoperative AOFAS scores and CSI measurements. Postoperative anatomical parameters achieved significantly better results than preoperative anatomical parameters. In conclusion, the use of interference screw in subtalararthroereisis for the treatment of pediatric flexible flatfoot deformity is an effective, simple and minimally invasive solution.


Assuntos
Pé Chato , Adolescente , Parafusos Ósseos , Criança , Pé Chato/diagnóstico por imagem , Pé Chato/cirurgia , Humanos , Osteotomia , Qualidade de Vida , Radiografia , Resultado do Tratamento
12.
Org Lett ; 22(18): 7098-7102, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32806143

RESUMO

A phthalaldehyde-substituted phthalocyanine has been synthesized that can conjugate with a range of biomolecules, including peptides, monosaccharides, lipids, and DNAs, and be immobilized on the surface of bovine serum album nanoparticles and glass slides using the versatile and efficient phthalaldehyde-amine capture reactions. The light-induced cytotoxic effects of the latter two materials have also been examined against cancer cells and bacteria, respectively, showing that they are highly efficient photosensitizing systems for photodynamic therapy.

13.
Chem Commun (Camb) ; 56(7): 1078-1081, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31872834

RESUMO

A boron dipyrromethene based photosensitiser substituted with a 1,2,4,5-tetrazine moiety has been prepared of which the photoactivity can be activated upon an inverse-electron-demand Diels-Alder reaction with trans-cyclooctene derivatives. By using a biotin-conjugated trans-cyclooctene to tag the biotin-receptor-positive HeLa cells, this photosensitiser exhibits site-specific activation through cycloaddition, leading to high photocytotoxicity.


Assuntos
Compostos de Boro/farmacologia , Compostos Heterocíclicos com 1 Anel/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/efeitos da radiação , Biotina/análogos & derivados , Biotina/síntese química , Biotina/farmacologia , Compostos de Boro/síntese química , Compostos de Boro/efeitos da radiação , Linhagem Celular Tumoral , Reação de Cicloadição , Ciclo-Octanos/síntese química , Ciclo-Octanos/química , Ciclo-Octanos/farmacologia , Compostos Heterocíclicos com 1 Anel/síntese química , Compostos Heterocíclicos com 1 Anel/efeitos da radiação , Humanos , Luz , Fotoquimioterapia , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/efeitos da radiação , Oxigênio Singlete/metabolismo
14.
Orthop Surg ; 12(1): 124-132, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31849195

RESUMO

OBJECTIVE: To assess the long-term outcomes after percutaneous reduction (PR) and screw fixation versus plate fixation via the sinus tarsi approach (STA) for displaced intra-articular calcaneal fractures (DIACF). METHODS: This retrospective study included a total of 150 patients (June 2008-August 2011), comprising 85 men and 65 women (mean age, 38.4 years), who were assigned to the PR group or the STA group. The inclusion criteria were DIACF (>2 mm) including Sanders type II and III, closed fracture, unilateral fracture, no history of smoking or no smoking during hospitalization and 3 months after surgery, and follow-up time not less than 8 years. The exclusion criteria were clear surgical contraindications (severe cardiovascular and cerebrovascular diseases), local or systemic infection symptoms, diagnosis with diabetes or lower extremity vascular disease, and Sanders type IV or open fractures. Outcomes were assessed by means of the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot scores, radiographic images, and postoperative complications. RESULTS: The mean follow-up period was 8.7 years (range, 8.0-10.0 years). The AOFAS scores in the PR group during the follow-up period were 54.2 ± 5.1, 85.8 ± 4.0, 88.1 ± 3.8, 87.9 ± 3.6, 87.8 ± 3.9, 86.9 ± 3.9, respectively, and in the STA group were 55.0 ± 5.6, 84.5 ± 5.2, 87.1 ± 3.8, 86.9 ± 3.8, 87.7 ± 3.3, and 87.6 ± 2.8, respectively. There was no significant difference in AOFAS scores, Bohler's angle, Gissane's angle, calcaneal length, and height between the two groups (P > 0.05). The good to excellent rate of the PR group (80.8%) was less than that of the STA group (91.7%) (P = 0.055). For Sanders III fractures, the good to excellent rate of the PR group (33.3%) was less than that of the STA group (76.9%) (P = 0.029). For calcaneal width recovery, the STA group performed better than the PR group (P < 0.05). The incidence of postoperative complications in the PR group (12.8%) was lower than that in the STA group (27.8%) (P = 0.026), of which the incidence of wound complications was 3.8% in the PR group and 13.9% in the STA group (P = 0.041). In addition, there was no significant difference in other postoperative complications such as sural nerve injury, peroneus longus and brevis muscle injury, calcaneal valgus symptoms, lateral impingement symptoms, and subtalar arthritis (P > 0.05). CONCLUSION: From the 8-10-year follow-up results of PR and STA as surgical procedures for the treatment of DIACF, it was found that there was no significant difference in the overall efficacy between them. STA was found to be superior to the PR in terms of the recovery of calcaneal width, providing more stable fixation for Sanders III fractures. PR was found to be more effective in reducing wound complications.


Assuntos
Placas Ósseas , Parafusos Ósseos , Calcâneo/cirurgia , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/cirurgia , Adulto , Calcâneo/lesões , Feminino , Seguimentos , Fixação Interna de Fraturas/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
J Foot Ankle Surg ; 59(3): 522-528, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31864842

RESUMO

Many lateral malleolus fractures have been found to have syndesmosis injuries after anatomic reduction. The main methods for the treatment of syndesmosis injuries are screw fixation and suture-button flexible fixations. In pursuit of innovation, we have designed a novel syndesmotic plate (NSP) for simultaneous fixation of lateral malleolus fractures and distal tibiofibular syndesmosis injuries. The purpose of this study is to compare the biomechanical characteristics of the NSP to syndesmotic screw and suture-button fixations. Twelve adult cadaveric specimens were used in this experiment. Axial loading as well as rotation torque were applied in 3 different ankle positions: neutral, dorsiflexion, and plantarflexion. After the initial specimens were tested, they were made into a pronation-abduction III fracture model as described by Lauge-Hansen. Subsequently, the specimens were fixed sequentially using a distal fibular anatomic locking plate (DFALP) combined with syndesmotic screws, DFALP combined with suture button, and NSP. Then the above tests were repeated. The syndesmotic displacement and the strain of the tibia and fibula were recorded during the experiment. In most cases, the displacements and strains of the NSP group and the screw group were smaller than the suture button groups and the native (SBGAN) (p < .05), and the displacements and strains of the NSP group were also slightly smaller than the screw group in most cases, and there was no significant difference between the 2 groups. The NSP we developed has a fixed strength no less than the traditional syndesmotic screw fixation. This provides us a new idea for the treatment of distal tibiofibular syndesmosis injuries.


Assuntos
Fraturas do Tornozelo/cirurgia , Traumatismos do Tornozelo/cirurgia , Placas Ósseas , Parafusos Ósseos , Fixação Interna de Fraturas/instrumentação , Âncoras de Sutura , Adulto , Fraturas do Tornozelo/fisiopatologia , Traumatismos do Tornozelo/fisiopatologia , Cadáver , Feminino , Fixação Interna de Fraturas/métodos , Humanos , Masculino , Amplitude de Movimento Articular , Técnicas de Sutura , Suporte de Carga
16.
Dalton Trans ; 45(23): 9669-75, 2016 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-27225044

RESUMO

LiNi0.6Co0.2Mn0.2O2 cathode material has been surface-modified by coating with ultrathin TiO2via atomic layer deposition (ALD) technology to improve the electrochemical performance of LiNi0.6Co0.2Mn0.2O2 cathodes for lithium ion batteries. Within the cut-off voltage of 2.5-4.3 V, the coated sample delivers an initial discharge capacity of 187.7 mA h g(-1) at 0.1 C and with a capacity retention about 85.9% after 100 cycles at 1 C, which provides a significant improvement in terms of discharge capacity and cyclability, as compared with those of the bare one. Such enhanced electrochemical performance of the coated sample is ascribed to its high-quality ultrathin coating of amorphous TiO2, which can protect the active material from HF attack, withstand the dissolution of metal ions in the electrode and favor the lithium diffusion of oxide as proved by electrochemical impedance spectroscopy (EIS) tests. TiO2 coating via the ALD process provides a potential approach for battery factories to surface-modify Ni-rich electrode materials so as to realize improvements in electrochemical performance.

17.
Biomacromolecules ; 14(8): 2593-600, 2013 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-23763628

RESUMO

Tobacco mosaic virus (TMV) is a classical viral nanoarchitecture that has been extensively employed as a promising template for the fabrication of novel nanomaterials and nanostructures. Despite being an ideal source, the Escherichia coli -derived TMV nanorod is suffering from tenuous assembly capability and stability. Inspired by the disulfide bond widely employed in biosystems, here we rationally introduce a cysteine into TMV coat protein (TMV-CP) to enable disulfide bond formation between adjacent subunits, thereby radically altering the behaviors of original noncovalent assembling system of wild type TMV-CP. The dramatically enhanced self-assembly capability and stability of the engineered TMV nanorods are observed and the essential roles of disulfide bonds are verified, illustrating a promising strategy to obtain desired genetic-modified nanorods that are inaccessible in plants. We expect this work will benefit the development of TMV-based nanotechnology and encourage the utilization of disulfide bonds in other biomacromolecules for improved properties as nanoscaffolds.


Assuntos
Proteínas do Capsídeo/química , Cistina/química , Nanotubos/química , Subunidades Proteicas/química , Vírus do Mosaico do Tabaco/química , Substituição de Aminoácidos , Proteínas do Capsídeo/genética , Escherichia coli , Concentração de Íons de Hidrogênio , Nanotubos/ultraestrutura , Multimerização Proteica , Estabilidade Proteica , Subunidades Proteicas/genética
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