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2.
Int J Biol Macromol ; 271(Pt 2): 132672, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38810855

RESUMO

Wound infection not only hinders the time sequence of tissue repair, but also may lead to serious complications. Multifunctional wound dressings with biocompatibility, excellent mechanical properties and antibacterial properties can promote wound healing during skin infection and reduce the use of antibiotics. In this study, a multifunctional dual-network antibacterial hydrogel was constructed based on the electrostatic interaction of two polyelectrolytes, hydroxypropyl trimethyl ammonium chloride chitosan (HACC) and sodium alginate (SA). Attributing to the suitable physical crosslinking between HACC and SA, the hydrogel not only has good biocompatibility, mechanical property, but also has broad-spectrum antibacterial properties. In vivo results showed that the hydrogel could regulate M2 polarization, promote early vascular regeneration, and create a good microenvironment for wound healing. Therefore, this hydrogel is an effective multifunctional wound dressing. Consequently, we propose a novel hydrogel with combined elements to expedite the intricate repair of wound infection.


Assuntos
Alginatos , Antibacterianos , Quitosana , Hidrogéis , Cicatrização , Cicatrização/efeitos dos fármacos , Hidrogéis/química , Hidrogéis/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Quitosana/química , Quitosana/farmacologia , Quitosana/análogos & derivados , Animais , Alginatos/química , Alginatos/farmacologia , Camundongos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologia , Infecções Bacterianas/tratamento farmacológico , Masculino , Bandagens , Staphylococcus aureus/efeitos dos fármacos
3.
RSC Adv ; 14(16): 10874-10883, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38577422

RESUMO

Antibacterial hydrogels have gained considerable attention for soft tissue repair, particularly in preventing infections associated with wound healing. However, developing an antibacterial hydrogel that simultaneously possesses excellent cell affinity and controlled release of metal ions remains challenging. This study introduces an antibacterial hydrogel based on alginate modified with bisphosphonate, forming a coordination complex with magnesium ions. The hydrogel, through an interpenetrating network with silk fibroin, effectively controls the release of magnesium ions and enhances strain resistance. The Alg-Mg/SF hydrogel not only demonstrates outstanding biocompatibility and broad-spectrum antibacterial properties but also stimulates macrophages to secrete anti-inflammatory factors. This advanced Alg-Mg/SF hydrogel provides a convenient therapeutic approach for chronic wound management, showcasing its potential applications in wound healing and other relevant biomedical fields.

4.
Int J Biol Macromol ; 268(Pt 2): 131827, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38670204

RESUMO

Cell culturing is a cornerstone of tissue engineering, playing a crucial role in tissue regeneration, drug screening, and the study of disease mechanisms. Among various culturing techniques, 3D culture systems, particularly those utilizing suspended fiber scaffolds, offer a more physiologically relevant environment than traditional 2D monolayer cultures. These 3D scaffolds enhance cell growth, differentiation, and proliferation by mimicking the in vivo cellular milieu. This review focuses on the critical role of suspended fiber scaffolds in tissue engineering. We compare the effectiveness of 3D suspended fiber scaffolds with 2D culture systems, discussing their respective benefits and limitations in the context of tissue regeneration. Furthermore, we explore the preparation methods of suspended fiber scaffolds and their potential applications. The review concludes by considering future research directions for optimizing suspended fiber scaffolds to address specific challenges in tissue regeneration, underscoring their significant promise in advancing tissue engineering and regenerative medicine.


Assuntos
Medicina Regenerativa , Engenharia Tecidual , Alicerces Teciduais , Alicerces Teciduais/química , Humanos , Engenharia Tecidual/métodos , Animais , Medicina Regenerativa/métodos , Regeneração , Diferenciação Celular , Técnicas de Cultura de Células/métodos , Proliferação de Células , Técnicas de Cultura de Células em Três Dimensões/métodos
5.
Bioact Mater ; 33: 572-590, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38111651

RESUMO

A central question in neural tissue engineering is how the tissue-engineered nerve (TEN) translates detailed transcriptional signals associated with peripheral nerve regeneration into meaningful biological processes. Here, we report a skin-derived precursor-induced Schwann cell (SKP-SC)-mediated chitosan/silk fibroin-fabricated tissue-engineered nerve graft (SKP-SCs-TEN) that can promote sciatic nerve regeneration and functional restoration nearly to the levels achieved by autologous nerve grafts according to behavioral, histological, and electrophysiological evidence. For achieving better effect of neuroregeneration, this is the first time to jointly apply a dynamic perfusion bioreactor and the ascorbic acid to stimulate the SKP-SCs secretion of extracellular matrix (ECM). To overcome the limitation of traditional tissue-engineered nerve grafts, jointly utilizing SKP-SCs and their ECM components were motivated by the thought of prolongating the effect of support cells and their bioactive cues that promote peripheral nerve regeneration. To further explore the regulatory model of gene expression and the related molecular mechanisms involved in tissue engineering-aided peripheral nerve regeneration, we performed a cDNA microarray analysis of gene expression profiling, a comprehensive bioinformatics analysis and a validation study on the grafted segments and dorsal root ganglia tissues. A wealth of transcriptomic and bioinformatics data has revealed complex molecular networks and orchestrated functional regulation that may be responsible for the effects of SKP-SCs-TEN on promoting peripheral nerve regeneration. Our work provides new insights into transcriptomic features and patterns of molecular regulation in nerve functional recovery aided by SKP-SCs-TEN that sheds light on the broader possibilities for novel repair strategies of peripheral nerve injury.

6.
Biomater Sci ; 11(22): 7358-7372, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37781974

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) has a signature of extremely high matrix stiffness caused by a special desmoplastic reaction, which dynamically stiffens along with the pathological process. The poor prognosis and low five-year survival rate of PDAC are partly owing to chemoresistance triggered by substrate stiffness. Understanding the potential mechanisms of matrix stiffness causing PDAC chemoresistance is of great significance. In this study, methacrylated gelatin hydrogel was used as platform for PANC-1 and MIA-PaCa2 cell culture. The results indicated that compared to soft substrate, stiff substrate distinctively reduced the gemcitabine sensitivity of pancreatic cancer. Intriguingly, transmission electron microscopy, immunofluorescence staining, western blot and qRT-PCR assay showcased that the number of autophagosomes and the expression of LC3 were elevated. The observations indicate that matrix stiffness may regulate the autophagy level, which plays a vital role during chemoresistance. In brief, soft substrate exhibited low autophagy level, while the counterpart displayed elevated autophagy level. In order to elucidate the underlying interaction between matrix stiffness-mediated cell autophagy and chemoresistance, rescue experiments with rapamycin and chloroquine were conducted. We found that inhibiting cell autophagy dramatically increased the sensitivity of pancreatic cancer cells to gemcitabine in the stiff group, while promoting autophagy-driven chemoresistance in the soft group, demonstrating that matrix stiffness modulated chemoresistance via autophagy. Furthermore, RNA-seq results showed that miR-1972 may regulate autophagy level in response to matrix stiffness. Overall, our research shed light on the synergistic therapy of PDAC combined with gemcitabine and chloroquine, which is conducive to promoting a therapeutic effect.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Desoxicitidina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Gencitabina , Neoplasias Pancreáticas/tratamento farmacológico , Autofagia , Cloroquina , Proliferação de Células , Neoplasias Pancreáticas
7.
Biomol Biomed ; 2023 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-37870482

RESUMO

Postoperative sore throat (POST) is a prevalent complication after general anesthesia and targeting high-risk patients help in its prevention. This study developed and validated a machine learning model to predict POST. A total number of 834 patients who underwent general anesthesia with endotracheal intubation were included in this study. Data from a cohort of 685 patients was used for model development and validation, whilst a cohort of 149 patients served for external validation. The prediction performance of random forest (RF), neural network (NN), and XGBoost models was compared using comprehensive performance metrics. The Local Interpretable Model-Agnostic Explanations (LIME) methods elucidated the best-performing model. POST incidences across training, validation, and testing cohorts were 41.7%, 38.4%, and 36.2%, respectively. Five predictors were age, sex, endotracheal tube cuff pressure, endotracheal tube insertion depth, and the time interval between extubation and the first drinking of water after extubation. After incorporating these variables, the NN model demonstrated superior generalization capabilities in predicting POST when compared to the XGBoost and RF models in external validation, achieving an area under the receiver operating characteristic curve (AUROC) of 0.81 (95% CI 0.74-0.89) and a precision-recall curve (AUPRC) of 0.77 (95% CI 0.66-0.86). The model also showed good calibration and clinical usage values. The NN model outperforms the XGBoost and RF models in predicting POST, with potential applications in the healthcare industry for reducing the incidence of this common postoperative complication.

8.
Bioact Mater ; 26: 249-263, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36936807

RESUMO

Chitosan and its degradation product, oligosaccharides, have been shown to facilitate peripheral nerve regeneration. However, the underlying mechanisms are not well understood. In this study, we analyzed the protein expression profiles in sciatic nerves after injury using proteomics. A group of proteins related to exosome packaging and transport is up-regulated by chitosan oligosaccharides (COS), implying that exosomes are involved in COS-induced peripheral nerve regeneration. In fact, exosomes derived from fibroblasts (f-EXOs) treated with COS significantly promoted axon extension and regeneration. Exosomal protein identification and functional studies, revealed that TFAP2C is a key factor in neurite outgrowth induced by COS-f-EXOs. Furthermore, we showed that TFAP2C targets the pri-miRNA-132 gene and represses miR-132-5p expression in dorsal root ganglion neurons. Camkk1 is a downstream substrate of miR-132-5p that positively affects axon extension. In rats, miR-132-5p antagomir stimulates CAMKK1 expression and improves axon regeneration and functional recovery in sciatic nerves after injury. Our data reveal the mechanism for COS in axon regeneration, that is COS induce fibroblasts to produce TFAP2C-enriched EXOs, which are then transferred into axons to promote axon regeneration via miR-132-5p/CAMKK1. Moreover, these results show a new facet of fibroblasts in axon regeneration in peripheral nerves.

9.
China Tropical Medicine ; (12): 1007-2023.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1016571

RESUMO

@#Abstract: Objective To report a case of suppurative knee arthritis caused by Pasteurella multocida and review relevant literature to improve the awareness of the clinical physicians regarding this bacterium and provide reference for clinical diagnosis and treatment. Methods A case of right knee suppurative arthritis caused by Pasteurella multocida was retrospectively reported and relevant literatures were reviewed in this article. Results The infected person was a 76-year-old female patient with a 5-year history of intermittent pain in his right knee and suffered from joint swelling, aggravation pain, and limited flexion and extension activities after intraarticular injection of sodium hyaluronate. After admission and completing all necessary tests, the patient was later confirmed to have been infected with Pasteurella multocida. The patient's right knee was promptly examined and cleared under arthroscopic surgery, synovium and meniscus were excised, a drainage tube was inserted, and continuous joint cavity irrigation was performed after the surgery, and then ceftriaxone was injected and amoxicillin/clavulanate potassium was taken orally for anti-infection and the patient's condition improved significantly after 26 days. Conclusions Pasteurella multocida infection cases are relatively rare, but the consequences in high-risk groups are relatively serious. Therefore, awareness of Pasteurella multocida and infection caused by it should be improved and high-risk groups should try to avoid contact with infectious sources as well as strengthen the management of pets so as to avoid infection.

10.
Front Bioeng Biotechnol ; 11: 1308761, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38162183

RESUMO

Peripheral nerve injury (PNI) is a neurological disorder caused by trauma that is frequently induced by accidents, war, and surgical complications, which is of global significance. The severity of the injury determines the potential for lifelong disability in patients. Artificial nerve scaffolds have been investigated as a powerful tool for promoting optimal regeneration of nerve defects. Over the past few decades, bionic scaffolds have been successfully developed to provide guidance and biological cues to facilitate Schwann cell myelination and orientated axonal growth. Numerous assessment techniques have been employed to investigate the therapeutic efficacy of nerve scaffolds in promoting the growth of Schwann cells and axons upon the bioactivities of distinct scaffolds, which have encouraged a greater understanding of the biological mechanisms involved in peripheral nerve development and regeneration. However, it is still difficult to compare the results from different labs due to the diversity of protocols and the availability of innovative technologies when evaluating the effectiveness of novel artificial scaffolds. Meanwhile, due to the complicated process of peripheral nerve regeneration, several evaluation methods are usually combined in studies on peripheral nerve repair. Herein, we have provided an overview of the evaluation methods used to study the outcomes of scaffold-based therapies for PNI in experimental animal models and especially focus on Schwann cell functions and axonal growth within the regenerated nerve.

11.
Polymers (Basel) ; 14(17)2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36080709

RESUMO

Polymer slurry is widely used in underground engineering treatment, but due to the concealed nature of underground projects, the diffusion pattern of slurry in the sand has been little studied. In this study, the basic physical properties of water-based polyurethane, oil-based polyurethane, and acrylate and epoxy resin were compared, and the performance of chemical grouted sands with different polymer slurry/sand mass ratios (PS/S) was tested. The higher the PS/S, the better the mechanical and impermeability properties of the chemical grouted sands. In this paper, water-based polyurethane was selected to carry out orthogonal tests on the diffusivity of slurry in sands. This experiment investigated the degree of influence of sand quality, grouting pressure and sand compactness on the diffusion of slurry in sands. The test results show that, in terms of factors affecting the final pressure of grouting, the sand density has the greatest influence, followed by the sand quality, and the grouting pressure is the smallest. In terms of slurry diffusibility, grouting pressure has the greatest influence, followed by sand compactness, and the sand quality is the smallest. The diffusion mechanism of slurry in the sand was deduced from the morphology of chemical grouted sands. Water-based polyurethane showed splitting-compression-penetration diffusion in sands of different grades, and the diffusion pattern of the slurry was not the same in low-pressure (1-1.5 MPa) grouting and high-pressure (2 MPa) grouting, and lateral splitting occurred in the case of high-pressure grouting diffusion.

12.
Polymers (Basel) ; 14(14)2022 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-35890558

RESUMO

A large number of drainage pipes and canals in China have been in disrepair for a long time and there have been problems such as leakage and corrosion. In response to these problems, this paper studies a non-excavation technology for repairing the arched canal structure-the in-situ spraying method. To study the influence of the original canal structure on the mechanical characteristics of the lining structure by in-situ spraying and the restraint effect on the lining structure, a field model test with a similar ratio of 1:2 was conducted in the field test pit. By conducting four stages of three-point concentrated load loading tests, the mechanical characteristics of the lining structure were investigated to reveal the influence of the canal structure on the force of the lining structure. The test results show that: the maximum crack width of the newly added lining structure is 0.27 mm and the normal service ultimate bearing capacity of the arched structure repaired by H-70 reaches 150 kN; comparing the loading test and the numerical simulation results, the difference between the two vault displacement results is 4.65% and the results are relatively consistent. The displacement of the bottom of the lining structure is small and the participation of the bottom plate is small, while the displacement of the upper arch structure of the lining is significantly larger than the lateral displacement, indicating that the canal structure can effectively limit the lateral displacement of the newly added lining and that the canal structure is greatly reduced. The bending moment of the lining structure is improved and the restraint effect on the arch foot is more obvious. This paper proposes the use of H-70 to repair arched canal structures by the in-situ spraying method and seeks to prove the feasibility of this method and fill the gap of research in this area. This paper provides the structural design basis and experimental knowledge for the construction of the repair method, which has important practical significance for the pipeline repair project in the future.

13.
J Mater Chem B ; 10(10): 1582-1590, 2022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-35156678

RESUMO

Peripheral nerve injuries are serious clinical events, and surgical treatment has certain limitations. Conductive hydrogels are promising biomaterials for neural tissue engineering, as they can enhance the functionality of neurons and Schwann cells (SCs) by mimicking the biophysical and biochemical cues existing in the natural extracellular matrix. It remains unexplored, however, whether there is a connection between the effects of different cues, such as hydrogel elasticity and conductivity, on SC fate. In the present work, we fabricated a series of conductive biocomposite hydrogels with the combination of silk fibroin (SF) and graphene oxide (GO) nanosheets and demonstrated an approach to control hydrogel electrical conductivity, independent of matrix elasticity and polymer concentration. Our results indicated that the soft substrates play a more critical role in SC survival, proliferation, spreading, and gene expression of neurotrophic factors, while the increased conductivity may also be beneficial to SC functional behaviors. These findings may promote the understanding of cell-matrix interactions and provide new insights for the design of neural tissue engineering scaffolds.


Assuntos
Sinais (Psicologia) , Hidrogéis , Condutividade Elétrica , Hidrogéis/farmacologia , Células de Schwann , Alicerces Teciduais
14.
J Biol Chem ; 298(3): 101718, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35151688

RESUMO

Peripheral myelination is a complicated process, wherein Schwann cells (SCs) promote the formation of the myelin sheath around the axons of peripheral neurons. Fibroblasts are the second resident cells in the peripheral nerves; however, the precise function of fibroblasts in SC-mediated myelination has rarely been examined. Here, we show that exosomes derived from fibroblasts boost myelination-related gene expression in SCs. We used exosome sequencing, together with bioinformatic analysis, to demonstrate that exosomal microRNA miR-673-5p is capable of stimulating myelin gene expression in SCs. Subsequent functional studies revealed that miR-673-5p targets the regulator of mechanistic target of the rapamycin (mTOR) complex 1 (mTORC1) tuberous sclerosis complex 2 in SCs, leading to the activation of downstream signaling pathways including mTORC1 and sterol-regulatory element binding protein 2. In vivo experiments further confirmed that miR-673-5p activates the tuberous sclerosis complex 2/mTORC1/sterol-regulatory element binding protein 2 axis, thus promoting the synthesis of cholesterol and related lipids and subsequently accelerating myelin sheath maturation in peripheral nerves. Overall, our findings revealed exosome-mediated cross talk between fibroblasts and SCs that plays a pivotal role in peripheral myelination. We propose that exosomes derived from fibroblasts and miR-673-5p might be useful for promoting peripheral myelination in translational medicine.


Assuntos
Alvo Mecanístico do Complexo 1 de Rapamicina , MicroRNAs , Bainha de Mielina , Células de Schwann , Proteína de Ligação a Elemento Regulador de Esterol 2 , Proteína 2 do Complexo Esclerose Tuberosa , Esclerose Tuberosa , Exossomos/genética , Exossomos/metabolismo , Fibroblastos/metabolismo , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Bainha de Mielina/metabolismo , Células de Schwann/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Esteróis/metabolismo , Esclerose Tuberosa/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo
15.
Materials (Basel) ; 14(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34300701

RESUMO

The acid-alkaline-inducd corrosive environments inside wastewater concrete pipelines cause concrete structural deterioration and substantial economic losses all over the world. High-performance concrete/mortar (HPC) was designed to have better resistance to corrosive environments, with enhanced service life. However, the durability of HPC in wastewater pipeline environments has rarely been studied. A high-performance mortar mixture (M) reinforced by supplemental materials (including fly ash and silica fume) and polyvinyl alcohol (PVA) fibers, together with a mortar mixture (P) consisting of cement, sand and water with similar mechanical performance, were both designed and exposed to simulated wastewater pipeline environments. The visual appearance, dimensional variation, mass loss, mechanical properties, permeable pore volume, and microstructure of the specimens were measured during the corrosion cycles. More severe deterioration was observed when the alkaline environment was introduced into the corrosion cycles. Test results showed that the M specimens had less permeable pore volume, better dimensional stability, and denser microstructure than the P specimens under acid-alkaline-induced corrosive environments. The mass-loss rates of the M specimens were 66.1-77.2% of the P specimens after 12 corrosion cycles. The compressive strength of the M specimens was 25.5-37.3% higher than the P specimens after 12 cycles under corrosive environments. Hence, the high-performance mortar examined in this study was considered superior to traditional cementitious materials for wastewater pipeline construction and rehabilitation.

16.
ACS Biomater Sci Eng ; 7(8): 3793-3805, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34251797

RESUMO

Type 1 diabetes mellitus (T1DM), as an autoimmune deficiency disease, is associated with an absolute deficiency of insulin subject to islet ß-cell destruction. Insulin-producing cells (IPCs) differentiated from induced pluripotent stem cells are an ideal replacement origin of ß-cells, which can be applied for cell transplantation therapies in T1DM. At present, more strategies focus on inducing and differentiating to obtain IPCs; however, the unsatisfactory differentiation efficiency and the lack of ideal carriers for in vivo transplantation limited their application. It is necessary to consider the cell microenvironment by constructing a biomimetic niche to improve the differentiation and transplantation efficiency. The main components of the extracellular matrix derived from pancreatic (the niche of ß-cells) decellularization were retained, which could provide the ideal extracellular microenvironment for IPCs. In this research, a hydrogel prepared with alginate (Alg) and the pancreatic extracellular matrix (pECM) was assessed for the beneficial outcomes on encapsulated IPCs. The results showed that pECM/Alg improved the differentiation efficiency and promoted insulin secretion and the expression of insulin-related genes as well. Besides, pECM/Alg-encapsulated IPCs exhibited obvious biocompatibility in vivo, which can prolong the transplantation effect and hypoglycemic function by reducing the inflammatory reaction. RNA-seq indicated that the PI3K/Akt pathway may be related to the improvement of the differentiation efficiency and function of IPCs. In general, the pECM/Alg hydrogel provides an ideal biomimetic microenvironment for IPCs and is suitable for in vivo transplantation.


Assuntos
Células Secretoras de Insulina , Alginatos , Matriz Extracelular , Hidrogéis , Insulina , Fosfatidilinositol 3-Quinases
17.
J Biomater Sci Polym Ed ; 32(2): 151-165, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32867627

RESUMO

Islet transplantation is considered as one of the promising treatment options for curing diabetes. However, the extracellular matrix (ECM) is destroyed during the process of islet isolation and extraction, which leads to decreased islet activity in vitro. ECM-based biomaterials which used to reconstruct the microenvironment of cells have been applied in various fields. In this study, an electrospinning hybrid scaffolds with silk fibroin (SF) and pig pancreatic decellularized extracellular matrix (P-dECM) have been prepared to mimic the islet ECM in vivo. Furthermore, the activity and function of islet were evaluated in vitro. The microstructures, hydrophilia and the main components of scaffolds were characterized by SEM, contact angle analysis and immunohistochemical experiment. The toxicity of stents was assessed by MTT assay. Cell activity and function were estimated by the live-dead cell staining, immunofluorescence, glucose-stimulated insulin secretion assay and q-PCR. A nanofiber scaffold with good hydrophilicity, non-toxic and retention of key ECM components has been obtained, which can improve the survival and promote and function of islets. This scaffold can be a promising candidate for pancreatic tissue engineering and provides a new strategy for islet transplantation.


Assuntos
Fibroínas , Animais , Biomimética , Matriz Extracelular , Seda , Suínos , Engenharia Tecidual , Alicerces Teciduais
18.
Front Bioeng Biotechnol ; 9: 777320, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35198548

RESUMO

Silk, as a kind of natural fibrin, has been prepared into various biomaterials due to its excellent biocompatibility and mechanicalness. However, there are some controversies on the biocompatibility of silk fibroin (SF), especially when it coexists with sericin. In this study, two kinds of silk from Jiangsu and Zhejiang were degummed with two concentrations of Na2CO3 solution, respectively, to obtain four kinds of silk fibroin. The effects of different degumming treatments on silk fibroin properties were analyzed by means of color reaction, apparent viscosity measurement, and transmission electron microscope and isobaric tags for relative and absolute quantification analyses, and the effects of different silk fibroin membranes on the growth of Schwann cells were evaluated. The results showed that the natural silk from Zhejiang treated with 0.05% Na2CO3 solution had a fuller structure, higher apparent viscosity, and better protein composition. While SF obtained by degumming with 0.5% Na2CO3 solution was more beneficial to cell adhesion and proliferation due to the thorough removal of sericin. This study may provide important theoretical and experimental bases for the selection of biomaterials for fabricating artificial nerve grafts.

19.
Front Cardiovasc Med ; 7: 585268, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33195471

RESUMO

Background: Rs13216675 T>C polymorphism, an SNP (single-nucleotide polymorphism) close to the gap junction protein alpha 1 (GJA1) gene, has been reported to be associated with risk of atrial fibrillation (AF); however, the results remained inconclusive. We aimed to perform a systematic review to clarify the relationship between rs13216675 and risk of AF. Materials and methods: We systematically searched the databases of PubMed, EMBASE, Web of Science, and the Chinese National Knowledge Infrastructure up to July 15, 2020. Data were synthesized using the random-effects model. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the relationship between rs13216675 and risk of AF. Results: Seven studies involving 39,827 cases and 458,466 controls were analyzed in the meta-analysis. The overall pooled OR of rs13216675 polymorphism for AF was significant (OR = 1.10, 95% CI = 1.07-1.12, P < 0.001) under the additive genetic model. Subgroup analyses revealed that rs13216675 polymorphism was significantly associated with AF in both Asians (OR = 1.12, 95% CI = 1.07-1.17, P < 0.001) and Europeans (OR = 1.09, 95% CI = 1.06-1.12, P < 0.001). When data were stratified by control sources, rs13216675 polymorphism was significantly related to AF in studies with both population-based controls (OR = 1.09, 95% CI = 1.07-1.12) and hospital-based controls (OR = 1.12, 95% CI = 1.07-1.17). No evidence of publication bias was detected. Conclusion: Our meta-analysis suggested that rs13216675 was significantly related to risk of AF and, therefore, might serve as a potential biological marker of AF.

20.
Biomaterials ; 255: 120164, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32554132

RESUMO

Electrical stimulation (ES) with conductive polymers can dramatically enhance neurite outgrowth and promote neural regeneration. However, besides ES, the practical applications of neural repair is also highly dependent on the nerve cell functionality and response to substrate conductivity. Therefore, the combination of the ES and suitable materials, such as tissue scaffolds, has been applied to facilitate treatment of neural injuries and demonstrated great potential in peripheral nerve regeneration. In this study, polypyrrole/silk fibroin (PPy/SF) conductive composite scaffold was fabricated by 3D bioprinting and electrospinning. Schwann cells seeded on these scaffolds were electrically stimulated and hence demonstrated enhanced viability, proliferation and migration, as well as upregulated expression of neurotrophic factors. Furthermore, the constructed PPy/SF conductive nerve guidance conduits accompanying with ES could effectively promote axonal regeneration and remyelination in vivo. Moreover, we found that the MAPKs signal transduction pathway was activated by ES at the conductive conduit. Our findings demonstrate that the PPy/SF conductive composite scaffolds with longitudinal guidance exhibit favorable properties for clinical use and promotes nerve regeneration and functional recovery.


Assuntos
Fibroínas , Polímeros , Animais , Estimulação Elétrica , Regeneração Nervosa , Pirróis , Engenharia Tecidual , Alicerces Teciduais
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