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1.
J Neuroinflammation ; 18(1): 64, 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33653377

RESUMO

BACKGROUND: Immune cell infiltration and neuroinflammation are heavily associated with spinal cord injury (SCI). C-C motif chemokine ligand 2/C-C chemokine receptor type 2 (CCL2/CCR2) axis has been identified as a critical role player during the invasion of immune cells to lesions in many diseases. γδ T cells, a subgroup of T cells, manage the course of inflammation response in various diseases; however, it remains unknown whether γδ T cells are recruited to injury site through CCL2/CCR2 signaling and exert the regulation effect on neuroinflammation after SCI. METHODS: Basso Mouse Scale (BMS), regularity index, cadence, max contact area, and motor-evoked potential testing (MEP) were measured to determine the neurological function recovery after spinal cord injury. Nissl staining was performed to identify the number of surviving motor neurons at lesion epicenter. Immunofluorescence, Western blot, enzyme-linked immunosorbent assays (ELISA), and quantitative real-time polymerase chain reaction (QRT-PCR) also were employed to evaluate the expression of associated proteins and genes. RESULTS: In this study, we demonstrated that TCRδ-/- mice present improved neurological recovery after SCI. γδ T cell recruitment to the SCI site was significantly reduced and motor functional improvement enhanced in CCL2-/- and CCR2-/- mouse strains. Furthermore, reconstitution of TCRδ-/- mice with γδ T cells extracted from CCR2-/- mice also showed similar results to CCL2 and CCR2 deficient mice. CONCLUSIONS: In conclusion, γδ T cell recruitment to SCI site promotes inflammatory response and exacerbates neurological impairment. CCL2/CCR2 signaling is a vital recruitment mechanism of γδ T cells to the SCI site, and it may be taken as a novel therapeutic target for future SCI.


Assuntos
Quimiocina CCL2/imunologia , Receptores CCR2/imunologia , Transdução de Sinais/imunologia , Traumatismos da Medula Espinal/imunologia , Linfócitos T/imunologia , Animais , Quimiocina CCL2/metabolismo , Quimiotaxia de Leucócito/imunologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores CCR2/metabolismo , Traumatismos da Medula Espinal/patologia , Linfócitos T/metabolismo
2.
Small ; 17(41): e2102102, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34510724

RESUMO

Neuroinflammation is critically involved in the repair of spinal cord injury (SCI), and macrophages associated with inflammation propel the degeneration or recovery in the pathological process. Currently, efforts have been focused on obtaining efficient therapeutic anti-inflammatory drugs to treat SCI. However, these drugs are still unable to penetrate the blood spinal cord barrier and lack the ability to target lesion areas, resulting in unsatisfactory clinical efficacy. Herein, a polymer-based nanodrug delivery system is constructed to enhance the targeting ability. Because of increased expression of matrix metalloproteinases (MMPs) in injured site after SCI, MMP-responsive molecule, activated cell-penetrating peptides (ACPP), is introduced into the biocompatible polymer PLGA-PEI-mPEG (PPP) to endow the nanoparticles with the ability for diseased tissue-targeting. Meanwhile, etanercept (ET), a clinical anti-inflammation treatment medicine, is loaded on the polymer to regulate the polarization of macrophages, and promote locomotor recovery. The results show that PPP-ACPP nanoparticles possess satisfactory lesion targeting effects. Through inhibited consequential production of proinflammation cytokines and promoted anti-inflammation cytokines, ET@PPP-ACPP could decrease the percentage of M1 macrophages and increase M2 macrophages. As expected, ET@PPP-ACPP accumulates in lesion area and achieves effective treatment of SCI; this confirmed the potential of nano-drug loading systems in SCI immunotherapy.


Assuntos
Traumatismos da Medula Espinal , Anti-Inflamatórios/uso terapêutico , Humanos , Imunoterapia , Macrófagos , Metaloproteinases da Matriz/uso terapêutico , Traumatismos da Medula Espinal/tratamento farmacológico
3.
Pak J Med Sci ; 37(2): 403-408, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33679922

RESUMO

OBJECTIVE: To investigate the biomechanical effects of osteoporosis on adjacent segments after posterior lumbar interbody fusion (PLIF). METHODS: This study was designed and conducted in the Traumatology and Orthopedics Laboratory, School of Chinese Medicine, Jinan University, Guangzhou, China, between December 2019 and February 2020. A healthy finite element model of L3-S1 was developed along with one PLIF model and one PLIF with osteoporosis model. Based on a hybrid test method, the inferior surface of S1 was entirely fixed, and a preload of 400N combined with an adjusted moment was imposed on the superior surface of L3 in each model to simulate flexion, extension, lateral bending and axial rotation. The intradiscal pressure (IDP), shear stress on annulus fibrosus, and the range of motion (ROM) of L3-L4 and L5-S1 were calculated and compared. RESULTS: In each direction, the highest value of IDP and shear stress on annulus fibrosus at L3-L4 and L5-S1 was found in the PLIF model, and the lowest value in the healthy model. The largest ROM at L4-L5 appeared in the healthy model, and the smallest value in the PLIF model in each direction. At L3-L4 and L5-S1, the highest ROM in most directions was found in the PLIF model, followed by the PLIF with osteoporosis model, and the lowest value in the healthy model. CONCLUSIONS: Osteoporosis can decrease IDP, shear stress on annulus fibrosus, and ROM at adjacent levels, and slow down the development of ASD after PLIF.

4.
Neurosurg Rev ; 43(3): 813-823, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30259268

RESUMO

Three fixation modalities including suture suspensory, anchor, and titanium plate are used extensively in unilateral open-door cervical laminoplasty. Nevertheless, up to now no systematic review and network meta-analysis have been published, and the differences in efficacy and safety of the three fixation modalities are still unclear. The purpose of this study is to compare the effectiveness and safety of the three fixation modalities including suture suspensory, anchor, and titanium plate in unilateral open-door cervical laminoplasty. Randomized controlled trials and cohort studies which compared the three interventions in unilateral open-door cervical laminoplasty were identified using the following databases: PubMed, Cochrane Library, Embase, Web of science, China National Knowledge Infrastructure, Chinese Science and Technology Periodical Database, and Wanfang data. Network meta-analysis was performed using R 3.4.3 software and STATA version 14.0. The results revealed that compared with suture suspensory, titanium plate and anchor showed the same effects in Japanese Orthopedic Association Scores, operative time, and blood loss. However, titanium plate showed superiority in postoperative range of motion of cervical spine, incidence of axial symptoms, and C5 paralysis; in terms of cervical curvature, titanium plate also showed better effectiveness than suture suspensory, but similar as anchor. Our network meta-analysis suggests that titanium plate is preferable to suture suspensory or anchor with more range of motion and lower incidence of axial symptoms and C5 paralysis. However, considering the limitations of this research, high-quality trials are needed in the future to evaluate the outcomes.


Assuntos
Vértebras Cervicais/cirurgia , Fixadores Internos , Procedimentos Neurocirúrgicos/métodos , Humanos , Laminoplastia , Metanálise em Rede , Resultado do Tratamento
5.
Pak J Med Sci ; 34(4): 879-885, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30190746

RESUMO

OBJECTIVE: To compare the effectiveness of exercise therapy with surgery for lumbar spinal stenosis. METHODS: Five English databases PubMed, the Cochrane Library, Web of science, OVID and PEDro database were searched for randomized controlled trials comparing surgical procedures with exercise therapy for lumbar spinal stenosis. Information on patients, study design, inclusion criteria, intervention and follow-up, outcomes, treatment details and adverse events were extracted. Meta-analysis was performed using Review Manager Version 5.3. RESULTS: Two randomized controlled trials and one mixed design trial with a total of 897 patients were included. The pooled results showed a significant difference between exercise and surgery in Oswestry Disability Index at two years (MD= 3.85, 95%CI: 0.48 to 7.22; P=0.03), but no significant difference at six months (MD= 2.18, 95%CI: -2.80 to 7.17; P=0.39) and one year (MD= 4.26, 95%CI: -1.79 to 10.32; P=0.17). In terms of physical function of 36 Items Short Form Health Survey, there were no significant differences between exercise and surgery at six months (MD= -2.23, 95% CI: -7.46 to 2.99; P=0.40), one year (MD= -2.17, 95% CI: -7.44 to 3.10; P=0.42) and two years (MD= -0.67, 95% CI: -6.16 to 4.82; P=0.81). CONCLUSION: In brief, the current evidence demonstrated a trend that exercise therapy had a similar effect for lumbar spinal stenosis compared with decompressive laminectomies. However, for the small sample size and low methodology quality of the included trials, some rigorously designed and large-scaled RCTs need to be performed to confirm the conclusion.

6.
Int J Biol Macromol ; 220: 1084-1094, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35985397

RESUMO

Hydrogels with fascinating adhesion have been demonstrated great potential in various applications. However, most hydrogels lose their adhesion in wet or underwater environments due to the influence of interfacial water. Inspired by mussel, an underwater adhesive hydrogel was facilely fabricated by introducing electrostatic interactions, which consisted of poly (acrylic acid) (PAA), quaternized xylan (QAX) and tannic acid (TA). In this hydrogel, -COO- from PAA, -N+(CH3)3 from QAX and catechol group from TA resembled amino acids with negative and positive charges and 3,4-dihydroxyphenylalanine units in mussel, which endowed the hydrogels with great underwater adhesion through multiple interactions. Notably, acrylic acid (AA) played a key role in the dispersion of the system. QAX, a biomass derived from plants with excellent properties, worked with PAA to construct hydrogel networks. The resultant hydrogels exhibited excellent mechanical properties including remarkable stretchability (>4000 %) and compressibility. Moreover, the hydrogels had superior UV-blocking (~99.96 %), and showed good adhesion both in air and underwater. The hydrogels can be exploited as a wearable sensor to monitor human motions and even subtle motions, which have the potential to be explored in human health monitoring.


Assuntos
Bivalves , Hidrogéis , Acrilatos , Adesivos/química , Animais , Bivalves/química , Catecóis/química , Di-Hidroxifenilalanina/química , Humanos , Hidrogéis/química , Taninos/metabolismo , Água/metabolismo , Xilanos/metabolismo
7.
Biomater Adv ; 133: 112624, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35525736

RESUMO

Human umbilical cord mesenchymal stem cell (hucMSC) derived exosomes (EXOs) have been investigated as a new treatment for spinal cord injury (SCI) because of their anti-inflammatory, anti-apoptotic, angiogenesis-promoting, and axonal regeneration properties. The CAQK peptide found in the brains of mice and humans after trauma has recently been found to specifically bind to the injured site after SCI. Thus, we developed a nanocarrier system called EXO-C@P based on hucMSC exosomes remodelled by the CRISPR/Cas9 plasmid to control inflammation and modified by the CAQK peptide. EXO-C@P was shown to effectively accumulate at the injury site and saturate the macrophages to significantly reduce the expression of inflammatory cytokines in a mouse model of SCI. Moreover, EXO-C@P treatment improved the performance of mice in behavioural assessments and upregulated soluble tumour necrosis factor receptor-1 (sTNFR1) in serum and at the trauma site after SCI surgery, but lowered the proportion of iNOS+ cells and the concentration of proinflammatory factors. In conclusion, EXO-C@P provides an effective alternative to multiple topical administration and drug delivery approaches for the treatment of SCI. STATEMENT OF SIGNIFICANCE: SCI is a serious disease characterised by a high incidence, high disability rate, and high medical costs, and has become a global medical problem. Several studies have shown that the inflammatory response is the critical inducer of secondary injury after SCI. The inflammatory cytokine TNF-α is considered to be one of the most significant therapeutic targets for autoimmune diseases. Antibodies targeting TNF-α and sTNFR1 are capable of neutralising free TNF-α. In this study, exosomes in the CRISPR/Cas9 system were used to establish stem cells with an autoregulated and feedback-controlled TNF-α response, with these cells secreting sTNFR1, which neutralised TNF-α and antagonised the inflammation stimulated by TNF-α. Moreover, the plasmid was combined with CAQK, which targeted the injury site and promoted the recovery of SCI function.


Assuntos
Exossomos , Células-Tronco Mesenquimais , Traumatismos da Medula Espinal , Sistemas CRISPR-Cas , Citocinas/metabolismo , Exossomos/metabolismo , Retroalimentação , Humanos , Fatores Imunológicos/metabolismo , Imunoterapia , Inflamação/metabolismo , Células-Tronco Mesenquimais/metabolismo , Plasmídeos , Traumatismos da Medula Espinal/terapia , Fator de Necrose Tumoral alfa/metabolismo , Cordão Umbilical/metabolismo
8.
Curr Med Chem ; 28(40): 8296-8318, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33557729

RESUMO

BACKGROUND: Cellulose, having huge reserves of natural polymers, has been widely applied in pharmaceutical and biomedicine fields due to its good biocompatibility, biodegradability, non-toxicity and excellent mechanical properties. At present, water- resistant metal-based and petroleum-based materials applied in the medical field have obvious problems of poor biocompatibility and high cost. Therefore, water-resistant cellulose- based materials with good biocompatibility and low price have become an attractive alternative. This review aims to summarize the preparation of water-resistant cellulose- based materials and their potential application in pharmaceutical and biomedical in recent years. METHODS: Common hydrophobic treatments of cellulose fibers or paper were overviewed. The preparation, properties and applications of water-resistant cellulose- based materials in the pharmaceutical and biomedical fields were summarized. RESULTS: Common hydrophobic treatments of cellulose fibers or paper were divided into chemical modification (graft polymerization, crosslinking, solution casting or dip-coating), physico-chemical surface modifications (plasma treatments, surface patterning, electrostatic spraying and electrowetting) and physical processing (electrostatic spinning, SAS process and 3D EHD printing). These hydrophobically processed cellulose fibers or paper could be prepared into various water-resistant cellulose-based materials and applied in pharmaceutical excipients, drug-loaded amphiphilic micelles, drug-loaded composite fibers, hydrophobic biocomposite film/coatings and paper-based detectors. They presented excellent water resistance and biocompatibility, low cytotoxicity and high drug loading ability, and stable drug release rate, etc., which could be used for water-insoluble drugs carriers, wound dressings, and medical testing equipment. CONCLUSION: Currently, water-resistant cellulose-based materials were mainly applied in water-insoluble drugs delivery carriers, wound dressing and medical diagnosis and presented great application prospects. However, the contradiction between hydrophobicity and mechanical properties of these reported water-resistant cellulose-based materials limited their wider application in biomedicine such as tissue engineering. In the future, attention will be focused on the higher hydrophobicity of water-resistant cellulose-based materials with excellent mechanical properties. In addition, clinical medical research of water-resistant cellulose-based materials should be strengthened.


Assuntos
Celulose , Água , Materiais Biocompatíveis , Humanos , Hidrogéis , Polímeros , Engenharia Tecidual
9.
World Neurosurg ; 146: e739-e746, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33171324

RESUMO

BACKGROUND: Adjacent segment degeneration is a common complication following anterior lumbar interbody fusion (ALIF). Osteoporosis is becoming increasingly prevalent in the elderly population and thus patients undergoing ALIF may experience osteoporosis with age. However, the influence of osteoporosis on adjacent segment degeneration after ALIF remains unclear. METHODS: Three finite element models of the L3-S1 segment, including a healthy model, an ALIF model, and an ALIF with osteoporosis model, were used for analysis. ALIF was simulated at the L4-L5 segment. Based on a hybrid test method, the models were imposed with a preload of 400 N and an adjusted moment in flexion, extension, lateral bending, and axial torsion. Intradiscal pressure, shear stress on anulus fibrosus, and range of motion at L3-L4 and L5-S1 were calculated and compared. RESULTS: In each direction, the maximal values of intradiscal pressure and shear stress on anulus fibrosus at L3-L4 and L5-S1 were found in the ALIF model, and the minimal values were found in the healthy model. At L3-L4 and L5-S1, the maximal values of range of motion in most directions were found in the ALIF model followed by the ALIF with osteoporosis model, and the minimal values were found in the healthy model. However, the maximal value of range of motion at L5-S1 in axial torsion was found in the ALIF with osteoporosis model. CONCLUSIONS: Osteoporosis may mitigate the adverse influence of ALIF on adjacent segments.


Assuntos
Degeneração do Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/cirurgia , Osteoporose/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Fusão Vertebral , Análise de Elementos Finitos , Humanos , Estresse Mecânico
10.
World Neurosurg ; 145: 462-470.e1, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32891841

RESUMO

BACKGROUND: Vertebroplasty (VP), kyphoplasty (KP), SpineJack system (SJ), radiofrequency kyphoplasty (RFK), Kiva system (Kiva), Sky kyphoplasty system (SK), and conservative treatment are widely used in the treatment of osteoporotic vertebral compression fractures (OVCFs). However, it is still unknown which is the best intervention. The aim of the current study was to evaluate the effectiveness and safety of VP, KP, SJ, RFK, Kiva, SK, and CT in the treatment of OVCFs. METHODS: Randomized controlled trials and cohort studies comparing VP, KP, SJ, RFK, Kiva, SK, or CT for the treatment of OVCFs were identified on the basis of databases including PubMed, the Cochrane Library, Web of Science, and Springer Link. A network meta-analysis was performed using STATA 15.1. RESULTS: A total of 56 studies with 6974 patients and 7 interventions were included in this study. The results of the surface under the cumulative probability demonstrated that SK was the best intervention in decreasing VAS scores and recovering middle vertebral height, RFK was the best intervention in improving ODI scores and decreasing incidence of new fractures, SJ was the best intervention to restore kyphosis angle, and Kiva was the best intervention to reduce incidence of bone cement leakage. Cluster analysis showed that SK was the preferable intervention on the basis of the outcomes of VAS, ODI, middle vertebral height, and kyphotic angle, and RFK was the preferable treatment in decreasing the incidence of adverse events. In our network meta-analysis, node-splitting analysis and loop inconsistency analysis showed no significant inconsistencies. CONCLUSIONS: SK may be the most effective treatment in relieving pain, improving the quality of life, and recovering vertebral body height and kyphotic angle, while RFK may be the safest intervention for OVCFs. However, considering the limitations of this study, more high-quality trials are needed in the future to confirm the current conclusion.


Assuntos
Fraturas por Compressão/terapia , Fraturas por Osteoporose/terapia , Fraturas da Coluna Vertebral/terapia , Tratamento Conservador/métodos , Humanos , Metanálise em Rede , Procedimentos Ortopédicos/métodos
11.
World Neurosurg ; 152: e700-e707, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34129985

RESUMO

BACKGROUND: Adjacent segmental degeneration (ASD) is one of the common complications after posterior lumbar interbody fusion (PLIF). Both whole body vibration (WBV) and osteoporosis are important factors associated with the biomechanics of the lumbar spine. However, to the best of our knowledge, no studies have investigated the effects of osteoporosis on ASD after PLIF under WBV. METHODS: In the present study, using one normal model, one PLIF model and one PLIF with osteoporosis model of the L1-S1 segment were developed. A 5-Hz, 40-N sinusoidal vertical load was imposed on the superior surface of L1 of each model to simulate WBV, and the dynamic responses and maximal values of intradiscal pressure, shear stress on annulus fibrosus, total deformation, and disc bulge were evaluated in the L1-L2, L2-L3, L3-L4, and L5-S1 segments. RESULTS: At the L1-L2, L2-L3, and L3-L4 levels, the differences in the dynamic responses and maximal values in intradiscal pressure, shear stress, total deformation, and disc bulge between the PLIF and PLIF with osteoporosis models were slight. However, at the L5-S1 level, the dynamic response curves and maximal intradiscal pressure, shear stress, and disc bulge values in the PLIF with osteoporosis model were significantly lower than those in the PLIF model. CONCLUSIONS: Osteoporosis can mitigate the development of ASD in the lower adjacent segment but has no obvious influence on the upper adjacent segments during WBV.


Assuntos
Degeneração do Disco Intervertebral/etiologia , Vértebras Lombares/cirurgia , Osteoporose/complicações , Complicações Pós-Operatórias/epidemiologia , Fusão Vertebral/métodos , Vibração , Fenômenos Biomecânicos , Simulação por Computador , Análise de Elementos Finitos , Humanos , Disco Intervertebral/diagnóstico por imagem , Modelos Biológicos , Amplitude de Movimento Articular
12.
J Leukoc Biol ; 110(6): 1131-1142, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34402106

RESUMO

Traumatic spinal cord injury (SCI) is a devastating condition marked by permanent motor, sensory, and autonomic dysfunction, in which the inflammatory response serves an important and preventable role. High mobility group box-1 (HMGB1) is a potent regulator of inflammation in numerous acute and chronic inflammatory conditions.; however, the role of HMGB1 in SCI remains unclear. The present study aimed to characterize the temporal dynamics of HMGB1 release after SCI, to investigate the role of spinal microglia activation in mediating the effects of HMGB1 on SCI, and to explore the therapeutic potential of intrathecal anti-HMGB1 polyclonal antibody on alleviating SCI. The present study demonstrated that HMGB1 expression was increased immediately after traumatic injury of a primary spinal neuron culture. It was found that neutralizing HMGB1 significantly ameliorated SCI pathogenesis and hind limb paralysis. Moreover, the levels of a number of pro-inflammatory cytokines in the SCI lesion were reduced when local HMGB1 was blocked by anti-HMGB1 antibody. In addition, the injured neuron-derived conditioned medium increased TNF-α secretion and the NF-κB pathway in the BV2 microglia cell line via HMGB1. Collectively, these results indicated that HMGB1 served an important role in SCI inflammation and suggested the therapeutic potential of an anti-HMGB1 antibody for SCI.


Assuntos
Proteína HMGB1/imunologia , Proteína HMGB1/metabolismo , Traumatismos da Medula Espinal/imunologia , Traumatismos da Medula Espinal/metabolismo , Animais , Citocinas/biossíntese , Feminino , Inflamação/imunologia , Inflamação/metabolismo , Microglia/metabolismo , Ratos , Ratos Sprague-Dawley
13.
Carbohydr Polym ; 240: 116289, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32475570

RESUMO

High strength and self-healing properties of hydrogels are of great interest in tissue engineering and biomedical fields. In this paper, nanocomposite hydrogels were prepared by freeze-thaw cycle method via fabricating physical cross-links into chemical-crosslinked formed polymer network. The properties of nanocomposite hydrogels were characterized by FTIR, XRD, SEM, rheological analysis, swelling analysis and mechanical test. The results showed that the electrostatic interaction between CNC and QAX and the high amount of PVA (20 wt%) were favorable to improve the mechanical properties of nanocomposite hydrogels, in which the maximum compressive strength and elongation at break of nanocomposite hydrogels were 1.56 MPa and 771 %, respectively. Prepared hydrogels achieved self-healing without any external stimuli at room temperature with the help of hydrogen bonds and the entanglement of long polymer chains, the healing efficiency was 37.03 % within 48 h. These hydrogels with high strength and self-healing properties will offer new insights for xylan application.


Assuntos
Celulose/química , Hidrogéis/química , Nanocompostos/química , Nanopartículas/química , Compostos de Amônio Quaternário/química , Xilanos/química , Álcool de Polivinil/química
14.
Curr Med Chem ; 27(28): 4593-4612, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32081105

RESUMO

BACKGROUND: Biosensors are widely applied for the detection of bio-molecules in blood glucose , cholesterol, and gene. Cellulose as the most dominating natural polymer has attracted more and more interest, especially in the field of medicine such as advanced medical diagnosis. Cellulose could endow biosensors with improved biocompatibility, biodegradability and nontoxicity, which could help in medical diagnosis. This mini-review summarizes the current development of cellulose-based biosensors as well as their applications in medical diagnosis in recent years. METHODS: After reviewing recent years' publications we can say that, there are several kinds of cellulose used in biosensors including different cellulose derivatives, bacterial cellulose and nanocellulose. Different types of cellulose-based biosensors, such as membrane, nano-cellulose and others were briefly described in addition to the detection principle. Cellulose-based biosensors were summarized as in the previous papers. The description of various methods used for preparing cellulose-based biosensors was also provided. RESULTS: Cellulose and its derivatives with their unique chemical structure proved to be versatile materials providing a good platform for achieving immobilizing bioactive molecules in biosensors. These cellulose-based biosensors possess various desirable properties such as accuracy, sensitivity, convenience, low cost and fast response. Among them, cellulose paper-based biosensors have the advantages of low cost and easy operation. Nano-cellulose has unique properties such as a large aspect ratio, good dispersing ability and high absorption capacity. CONCLUSION: Cellulose displays a promising application in biosensors which could be used to detect different bio-molecules such as glucose, lactate, urea, gene, cell, amino acid, cholesterol, protein and hydroquinone. In future, the attention will be focused on designing miniaturized, multifunctional, intelligent and integrated biosensors. Creation of low cost and environmentally friendly biosensors is also very important.


Assuntos
Técnicas Biossensoriais , Celulose , Polímeros
15.
Chemosphere ; 261: 127682, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32711240

RESUMO

Neonicotinoid insecticides (NEOs) have become the most widely used insecticides worldwide, and they are ubiquitous in food (i.e., fruit juices). In the present study, occurrence of seven NEOs and four metabolites (m-NEOs) in 400 fruit juice samples were investigated. NEOs and m-NEOs were frequently detected (65%-86%) in fruit juice samples. The median residues of NEOs and m-NEOs were ranged from 0.06 ng/mL to 0.94 ng/mL. Seasonal variations in NEOs and m-NEOs in fruit juices were found, indicating that the target analyte residues during the dry season were remarkably higher than those of residues during wet season. The relative potency factor (RPF) method was used to integrate individual NEOs into a single metric [imidacloprid (IMIRPF)] representing the intakes of IMI equivalent to total NEOs for each fruit juice sample. The estimated daily intake (EDI) of total NEOs for the general Chinese population was obtained. The median IMIRPF for total fruit juices was 13.4 ng/g, and the median EDI of NEOs was 18.2 ng/kg bw/day for the general population. Although the EDIs in this study were considerably lower than the acceptable daily intake (60 µg/kg bw/day, ADI), the dietary exposure risks for total NEOs should not be ignored because of the increasing usage of NEOs and their ubiquitous presence in fruit juices in China. To the best of our knowledge, this report was the first time to document residues of NEO and m-NEO in fruit juice samples collected from China.


Assuntos
Exposição Dietética/estatística & dados numéricos , Sucos de Frutas e Vegetais/análise , Inseticidas/análise , Neonicotinoides/análise , Povo Asiático , China , Coleta de Dados , Frutas/química , Humanos , Nitrocompostos , Nível de Efeito Adverso não Observado , Projetos de Pesquisa , Estações do Ano , Verduras/química
16.
Polymers (Basel) ; 11(4)2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30960605

RESUMO

Xylan-g-/P(AA-co-AM)/Graphene oxide (GO) hydrogels were prepared and used in the removal of heavy mental ions. Acrylamide (AM), acrylic acid (AA), and xylan were used as the raw materials to prepare the hydrogels with ammonium persulfate (APS) as the initiator. The prepared hydrogels were characterized by Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and energy dispersive X-ray (EDX). Some important properties of nanocomposite hydrogels such as swelling behavior, mechanical property, and adsorption capacity were also examined as well as the regeneration of the hydrogels. The results showed that the prepared hydrogels reached the equilibrium state of swelling after 12 h, and the compressive strength of the hydrogel with 30 mg of GO could reach up to 203 kPa. Compared with traditional hydrogel, the mechanical properties of the hydrogels with GO were obviously improved. The maximum adsorption capacity of hydrogels for Pb2+, Cd2+, and Zn2+ could reach up to 683 mg/g, 281 mg/g, and 135 mg/g, respectively. After five cycles of adsorption and desorption, the recovery rate of the hydrogels on Pb2+, Cd2+, and Zn2+ was still up to 87%, 80%, and 80%, respectively-all above 80%.

17.
Int J Biol Macromol ; 132: 978-986, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30880050

RESUMO

The effects of nano-ZnO and nano-SiO2 on the properties of PVA/xylan composite films were investigated in this work. Results showed that nano-ZnO and nano-SiO2 could effectively improve the mechanical strength, moisture and oxygen barrier properties and surface hydrophobic property of the composite films. The results of FTIR and XRD indicated the interaction of hydrogen bonds between nanoparticles and PVA and xylan. When the contents of nano-ZnO and nano-SiO2 in the composite films were 3%, the tensile strength was increased to 20.4 MPa and 22.5 MPa, respectively, while water vapor permeability (3.14 and 3.03 × 10-11 g·m-1·s-1·Pa-1) and oxygen permeability (5.28 and 5.003 cm3·m-2·24 h-1·0.1 MPa-1) reached the minima. With the increase of nano-ZnO and nano-SiO2 dosage, the solubility of composite films was increased. When the contents of nano-ZnO and nano-SiO2 were 3% and 4%, respectively, the contact angles of the films was increased up to 101° and 78°. Besides, the composite films with nano-ZnO exhibited UV shielding performance, whereas the ones with nano-SiO2 had similar UV light-transparency to the pure PVA/xylan composite films.


Assuntos
Nanocompostos/química , Nanopartículas/química , Álcool de Polivinil/química , Dióxido de Silício/química , Xilanos/química , Óxido de Zinco/química , Oxigênio/química , Permeabilidade , Solubilidade , Vapor , Propriedades de Superfície , Temperatura , Resistência à Tração
18.
Artigo em Inglês | MEDLINE | ID: mdl-31015852

RESUMO

BACKGROUND: Tuina, acupuncture, traction, and Chinese herbs play an important role in the treatment of lumbar disc herniation. However, the comparative effectiveness and safety of the four commonly utilized treatment modalities are still unclear. OBJECTIVE: To compare the effectiveness and safety of the four interventions for lumbar disc herniation. METHODS: Randomized controlled trials comparing any two of the four interventions in the treatment of lumbar disc herniation were identified using the following databases: PubMed, the Cochrane Library, Embase, Web of Science, the China National Knowledge Infrastructure, Chinese Science and Technology Periodical Database, and Wanfang data, and network meta-analysis was performed using STATA 14.0. RESULTS: One hundred and twenty-one studies involving a total of 13075 patients were included. In all the outcome measurements, traction demonstrated a worst effectiveness, and Tuina and acupuncture demonstrated a best effectiveness, but no significant differences were found between Tuina and acupuncture. Compared with Tuina or acupuncture, Chinese herbs showed a similar effectiveness in Visual Analogue Score and Japanese Orthopedic Association Scores, but an inferior effectiveness in invalid rate and cure rate. CONCLUSIONS: In the treatment of lumbar disc herniation, Tuina and acupuncture were superior to traction or Chinese herbs, and the effectiveness of traction was the worst. However, considering the limitations of this review, more high-quality trials, especially those comparing Chinese herbs with the other three interventions, should be carried out in the future to further confirm the current findings.

19.
Carbohydr Polym ; 209: 250-257, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30732806

RESUMO

Ancient papers, facing the threat of acidification, aging and microbial corrosion, need to be repaired due to their significance of history, art and culture research. In this work, a new and highly efficient approach was proposed to deacidify and strengthen aging paper by in-situ quaternization for the conservation, in which MgO nanoparticles dispersed in hexamethyldisiloxane was coated on the paper surface and the aqueous alkaline solution and the 2, 3-epoxypropyl trimethyl ammonium chloride/isopropyl alcohol/water mixture were sprayed in a closed reactor. Results showed that properties of ageing papers were improved after MSCE-8/2 treatment. The pH value was in the range of 7.5-9.0 and the maximum amount of alkali storage was 220 mmol/Kg. The tensile strength and folding endurance were increased by 28.05% and 80%, respectively. The fluctuation range of brightness and chromatic aberration was 0.14 and 1.27. Moreover, treated paper also had the great anti-bacteria and anti-aging effects.

20.
J Colloid Interface Sci ; 538: 507-518, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30544068

RESUMO

High strength hydrogels open new possibilities in the fields of bioengineering and biomedical. In this paper, a highly efficient one-pot strategy was developed to prepare carboxymethyl xylan-g-poly (acrylic acid) (CMX-g-PAA) hydrogels with high compression strength, high elongation and high elasticity by using the metal coordination and the reinforcement of hydroxylate multi-walled carbon nanotubes (HCNTs). Prepared hydrogels were characterized by means of FTIR, XRD, SEM, rheological measurements as well as their swelling and mechanical properties. Results showed that the Fe3+-carboxyl coordination and HCNTs imparted hydrogels with high strength and good rapid recovery properties, in which the maximum high compressive strength and elongation at break were achieved to 10.4 MPa and 1032%, and the shape of hydrogels almost returned to the original shape after the external force was removed after 30 cycles of compression. These hydrogels also exhibited Fe3+-triggered shape memory properties. Therefore, as-prepared hydrogels possessing high strength, rapid recovery and shape memory properties, could broaden access for application in intelligent toys, electronic skin, biosensing, and tissue engineering.

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