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The use of membrane-based guided bone regeneration techniques has great potential for single-stage reconstruction of critical-sized bone defects. Here, a multifunctional bone regeneration membrane combining flexible elasticity, electrical stimulation (ES) and osteoinductive activity is developed by in situ doping of MXene 2D nanomaterials with conductive functionality and ß-TCP particles into a Poly(lactic acid-carbonate (PDT) composite nano-absorbable membrane (P/T/MXene) via electrostatic spinning technique. The composite membrane has good feasibility due to its temperature sensitivity, elastic memory capacity, coordinated degradation profile and easy preparation process. In vitro experiments showed the P/T/MXene membrane effectively promoted the recruitment and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) under ES and enhanced the angiogenic capacity of endothelial cells, which synergistically promoted bone regeneration through neovascularization. In addition, an in vivo rat model of cranial bone defects further confirmed the bone regeneration efficacy of the P/T/MXene membrane. In conclusion, the developed P/T/MXene membrane can effectively promote bone regeneration through their synergistic multifunctional effects, suggesting the membranes have great potential for guiding tissue regeneration and providing guidance for the biomaterials design.
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OBJECTIVE: This study aimed to distinguish tuberculous spondylodiscitis (TS) from pyogenic spondylodiscitis (PS) based on laboratory, magnetic resonance imaging (MRI) and computed tomography (CT) findings. Further, a novel diagnostic model for differential diagnosis was developed. METHODS: We obtained MRI, CT and laboratory data from TS and PS patients. Predictive models were built using binary logistic regression analysis. The receiver operating characteristic curve was analyzed. Both internal and external validation was performed. RESULTS: A total of 81 patients with PS (n = 46) or TS (n = 35) were enrolled. All patients had etiological evidence from the focal lesion. Disc signal or height preservation, skip lesion or multi segment (involved segments ≥ 3) involvement, paravertebral calcification, massive sequestra formation, subligamentous bone destruction, bone erosion with osteosclerotic margin, higher White Blood Cell Count (WBC) and positive result of tuberculosis infection T cell spot test (T-SPOT.TB) were more prevalent in the TS group. A diagnostic model was developed and included four predictors: WBC<7.265 * (10^9/L), skip lesion or involved segments ≥ 3, massive sequestra formation and subligamentous bone destruction. The model showed good sensitivity, specificity, and total accuracy (91.4%, 95.7%, and 93.8%, respectively); the area under the receiver operating characteristic curve (AUC) was 0.981, similar to the results of internal validation using bootstrap resampling (1000 replicates) and external validation set, indicating good clinical predictive ability. CONCLUSIONS: This study develop a good diagnostic model based on both CT and MRI, as well as laboratory findings, which may help clinicians distinguish between TS and PS.
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Apoptosis has been regarded to mediate intervertebral disc degeneration (IDD); however, the basic question of how the apoptotic bodies are cleared in the avascular intervertebral disc without phagocytes, which are essential to apoptosis, remains to be elucidated. Our goals were to investigate the ultrastructure of nucleus pulposus (NP) cells undergoing chondroptosis, a variant of apoptotic cell death, in a rabbit annular needle-puncture model of IDD. Experimental IDD was induced by puncturing discs with a 16-G needle in New Zealand rabbits. At 4 and 12â weeks after puncture, progressive degeneration was demonstrated by X-ray, magnetic resonance imaging and histological staining. TUNEL staining suggested a significant increase in the apoptosis index in the degenerated NP. However, the percentage of apoptotic cells with the classic ultrastructure morphology was much less than that with chondroptotic ultrastructure morphology under transmission electron microscopy (TEM). The chondroptotic cells from the early to late stage were visualized under TEM. In addition, the percentage of chondroptotic cells was significantly enhanced in the degenerated NP. Furthermore, 'paralyzed' cells were found in the herniated tissue. Western blotting revealed an increase in caspase3 expression in the degenerated NP. The expression of the Golgi protein (58K) was increased by the fourth week after puncture but decreased later. These findings indicate that chondroptosis is a major type of programmed cell death in the degenerated rabbit NP that may be related to the progressive development of IDD.
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Apoptose , Degeneração do Disco Intervertebral/patologia , Núcleo Pulposo/ultraestrutura , Animais , Caspase 3/metabolismo , Modelos Animais de Doenças , Degeneração do Disco Intervertebral/diagnóstico por imagem , Masculino , Núcleo Pulposo/enzimologia , CoelhosRESUMO
OBJECTIVE: Adipose-derived stem cells (ADSCs) have been demonstrated to have an anti-apoptosis effect on chondrocytes; However, their effect on autophagic activation remains unclear. We sought to explore whether ADSCs can activate autophagy and inhibit IL-1ß- and lipopolysaccharide (LPS)-induced catabolism in chondrocytes. METHODS: ADSCs and chondrocytes were collected from SD rats. The biologic characteristics of ADSCs were analyzed by flow cytometric analysis, Oil red O and Alizarin Red staining. Autophagic level and autophagic flux were revealed by Western blotting for LC3-II and SQSTM1/P62, MDC (monodansylcadaverine) staining and mRFP-GFP-LC3 analysis. The mTOR pathway was investigated by Western blotting for p-mTOR. The mRNA level of matrix metalloproteinases (MMPs) and thrombospondin motifs (ADAMTSs) was detected by real-time PCR. RESULTS: The typical surface markers and differentiation potentials of ADSCs were proved. ADSCs enhanced the expression of LC3-II/LC3-I and reduced SQSTM1 levels in IL-1ß-induced chondrocytes after 24 and 48 h co-culturing and in LPS-induced chondrocytes after 48 h co-culturing respectively. mRFP-GFP-LC3 analysis suggested that autophagosomes and autolysosomes were formed earlier in IL-1ß-treated chondrocytes than in LPS-treated chondrocytes. Bafilomycin A1 treatment further increased the LC3-II/LC3-I level in chondrocytes in co-culture with ADSCs. The mTOR pathway was inhibited in the chondrocytes in co-culture with ADSCs. Finally, ADSCs inhibited the increase of MMPs and ADAMTSs in chondrocytes induced by IL-1ß and LPS. CONCLUSIONS: ADSCs seem able to activate autophagy and inhibit catabolism in chondrocytes in an inflammation environment, and the mTOR pathway might be involved in the autophagy activation.
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Condrócitos , Animais , Células Cultivadas , Citocinas , Ratos , Ratos Sprague-Dawley , Células-TroncoRESUMO
Extracellular acidification occurs under physiologic and pathologic conditions, such as exercise, ischemia, and inflammation. It has been shown that acidosis has various adverse effects on bone. In recent years there has been increasing evidence which indicates that ovarian cancer G protein-coupled receptor 1 (OGR1) is a pH-sensing receptor and mediates a variety of extracellular acidification-induced actions on bone cells and other cell types. Recent studies have shown that OGR1 is involved in the regulation of osteoclast differentiation, survival, and function, as well as osteoblast differentiation and bone formation. Moreover, OGR1 also regulates acid-induced apoptosis of endplate chondrocytes in intervertebral discs. These observations demonstrate the importance of OGR1 in skeletal development and metabolism. Here, we provide an overview of OGR1 regulation ofosteoclasts, osteoblasts, and chondrocytes, and the molecular actions of OGR1 induced by extracellular acidification in the maintenance of bone health.
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Ácidos/metabolismo , Osso e Ossos/metabolismo , Espaço Extracelular/metabolismo , Neoplasias Ovarianas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Feminino , Humanos , PrótonsRESUMO
The aim of this study was to evaluate the influence factors of metagenomic next-generation sequencing (mNGS) negative results in the diagnosed patients with spinal infection. mNGS test was applied in a cohort of 114 patients with suspected spinal infection, among which 56 patients had a final diagnosis of spinal infection. mNGS achieved a sensitivity of 75.0% (95% CI, 61.6% to 85.6%) and a specificity of 84.5% (95% CI, 72.6% to 92.7%), using histopathology and culture results as reference. Diagnosed patients with a negative culture result had lower white blood cell account, percentage of neutrophilic granulocyte, C-reactive protein (all P<0.05) and relatively higher rate of prior antimicrobial treatment history (P=0.059). However, diagnosed patients with a negative mNGS result did not have such difference with mNGS-positive patients, suggesting that mNGS was not strictly limited by the above indicators, which presented the advantages of this technique from another point of view.
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Sequenciamento de Nucleotídeos em Larga Escala , Metagenômica , Sensibilidade e Especificidade , Humanos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Masculino , Feminino , Metagenômica/métodos , Pessoa de Meia-Idade , Idoso , Adulto , Idoso de 80 Anos ou mais , Adulto Jovem , Doenças da Coluna Vertebral/microbiologia , Doenças da Coluna Vertebral/diagnósticoRESUMO
Intercellular communication between tumor cells and immune cells regulates tumor progression including positive communication with immune activation and negative communication with immune escape. An increasing number of methods are employed to suppress the dominant negative communication in tumors such as PD-L1/PD-1. However, how to effectively improve positive communication is still a challenge. In this study, a nuclear-targeted photodynamic nanostrategy is developed to establish positive spatiotemporal communication, further activating dual antitumor immunity, namely innate and adaptative immunity. The mSiO2 -Ion@Ce6-NLS nanoparticles (NPs) are designed, whose surface is modified by ionic liquid silicon (Ion) and nuclear localization signal peptide (NLS: PKKKRKV), and their pores are loaded with the photosensitizer hydrogen chloride e6 (Ce6). Ion-modified NPs enhance intratumoral enrichment, and NLS-modified NPs exhibit nuclear-targeted characteristics to achieve nuclear-targeted photodynamic therapy (nPDT). mSiO2 -Ion@Ce6-NLS with nPDT facilitate the release of damaged double-stranded DNA from tumor cells to activate macrophages via stimulator of interferon gene signaling and induce the immunogenic cell death of tumor cells to activate dendritic cells via "eat me" signals, ultimately leading to the recruitment of CD8+ T-cells. This therapy effectively strengthens positive communication to reshape the dual antitumor immune microenvironment, further inducing long-term immune memory, and eventually inhibiting tumor growth and recurrence.
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Nanopartículas , Fotoquimioterapia , Linhagem Celular Tumoral , Linfócitos T CD8-Positivos , Fármacos Fotossensibilizantes/farmacologia , Fotoquimioterapia/métodos , Macrófagos , Imunoterapia/métodos , Microambiente TumoralRESUMO
Coloading adjuvant drugs or biomacromolecules with photosensitizers into nanoparticles to enhance the efficiency of photodynamic therapy (PDT) is a common strategy. However, it is difficult to load positively charged photosensitizers and negatively charged adjuvants into the same nanomaterial and further regulate drug release simultaneously. Herein, a single-component dual-functional prodrug strategy is reported for tumor treatment specifically activated by tumor microenvironment (TME)-generated HOCl. A representative prodrug (DHU-CBA2) is constructed using indomethacin grafted with methylene blue (MB). DHU-CBA2 exhibited high sensitivity toward HOCl and achieved simultaneous release of dual drugs in vitro and in vivo. DHU-CBA2 shows effective antitumor activity against lung cancer and spinal metastases via PDT and cyclooxygenase-2 (COX-2) inhibition. Mechanistically, PDT induces immunogenic cell death but stimulates the gene encoding COX-2. Downstream prostaglandins E2 and Indoleamine 2,3 dioxygenase 1 (IDO1) mediate immune escape in the TME, which is rescued by the simultaneous release of indomethacin. DHU-CBA2 promotes infiltration and function of CD8+ T cells, thus inducing a robust antitumor immune response. This work provides an autoboost strategy for a single-component dual-functional prodrug activated by TME-specific HOCl, thereby achieving favorable tumor treatment via the synergistic therapy of PDT and a COX-2 inhibitor.
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Neoplasias Pulmonares , Fotoquimioterapia , Pró-Fármacos , Neoplasias da Coluna Vertebral , Humanos , Fármacos Fotossensibilizantes/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Ciclo-Oxigenase 2 , Linfócitos T CD8-Positivos , Neoplasias da Coluna Vertebral/tratamento farmacológico , Indometacina , Microambiente TumoralRESUMO
Peripheral nerve injury (PNI) remains a challenging area in regenerative medicine. Nerve guide conduit (NGC) transplantation is a common treatment for PNI, but the prognosis of NGC treatment is unsatisfactory due to 1) neuromechanical unmatching and 2) the intra-conduit inflammatory microenvironment (IME) resulting from Schwann cell pyroptosis and inflammatory-polarized macrophages. A neuromechanically matched NGC composed of regenerated silk fibroin (RSF) loaded with poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (P:P) and dimethyl fumarate (DMF) are designed, which exhibits a matched elastic modulus (25.1 ± 3.5 MPa) for the peripheral nerve and the highest 80% elongation at break, better than most protein-based conduits. Moreover, the NGC can gradually regulate the intra-conduit IME by releasing DMF and monitoring sciatic nerve movements via piezoresistive sensing. The combination of NGC and electrical stimulation modulates the IME to support PNI regeneration by synergistically inhibiting Schwann cell pyroptosis and reducing inflammatory factor release, shifting macrophage polarization from the inflammatory M1 phenotype to the tissue regenerative M2 phenotype and resulting in functional recovery of neurons. In a rat sciatic nerve crush model, NGC promoted remyelination and functional and structural regeneration. Generally, the DMF/RSF/P:P conduit provides a new potential therapeutic approach to promote nerve repair in future clinical treatments.
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Fibroínas , Regeneração Nervosa , Traumatismos dos Nervos Periféricos , Animais , Regeneração Nervosa/efeitos dos fármacos , Regeneração Nervosa/fisiologia , Ratos , Traumatismos dos Nervos Periféricos/terapia , Fibroínas/química , Fibroínas/farmacologia , Modelos Animais de Doenças , Ratos Sprague-Dawley , Células de Schwann/metabolismo , Regeneração Tecidual Guiada/métodos , Inflamação , Alicerces Teciduais/química , Nervo Isquiático/lesõesRESUMO
Oxidative stress can lead to nucleus pulposus cell (NPC) apoptosis, which is considered to be one of the main contributors to intervertebral disc degeneration (IVDD). Procyanidin B2 is a natural antioxidant that protects against oxidative stress. However, whether procyanidin B2 protects NPCs from oxidative stress remains unknown. In this study, we demonstrated that procyanidin B2 could reduce tert-butyl hydroperoxide-induced reactive oxygen species in rat NPCs and attenuate rat NPC apoptosis. Further experiments revealed that procyanidin B2 upregulated the expression of both nuclear factor erythroid 2-related factor 2 (Nrf2) and phosphorylation of protein kinase B (Akt). We then used silencing of Nrf2 and LY294002 to silence Nrf2 expression and block the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, respectively, and found that the protective roles of procyanidin B2 in NPCs were inhibited. Therefore, we demonstrated that procyanidin B2 alleviated rat NPC apoptosis induced by oxidative stress by upregulating Nrf2 via activation of the PI3K/Akt signaling pathway. This study provides a potential therapeutic approach for procyanidin B2 in IVDD, which might help in the development of new drugs for IVDD treatment.
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Degeneração do Disco Intervertebral , Núcleo Pulposo , Ratos , Animais , Proteínas Proto-Oncogênicas c-akt/fisiologia , Fosfatidilinositol 3-Quinase/metabolismo , Fosfatidilinositol 3-Quinase/uso terapêutico , Fosfatidilinositol 3-Quinases , Núcleo Pulposo/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fator 2 Relacionado a NF-E2/uso terapêutico , Estresse Oxidativo , Degeneração do Disco Intervertebral/tratamento farmacológico , Degeneração do Disco Intervertebral/metabolismo , ApoptoseRESUMO
Replicating the controlled nanofibrillar architecture of collagenous tissue represents a promising approach in the design of tendon replacements that have tissue-mimicking biomechanicsâoutstanding mechanical strength and toughness, defect tolerance, and fatigue and fracture resistance. Guided by this principle, a fibrous artificial tendon (FAT) was constructed in the present study using an engineering strategy inspired by the fibrillation of a naturally spun silk protein. This bioinspired FAT featured a highly ordered molecular and nanofibrillar architecture similar to that of soft collagenous tissue, which exhibited the mechanical and fracture characteristics of tendons. Such similarities provided the motivation to investigate FAT for applications in Achilles tendon defect repair. In vitro cellular morphology and expression of tendon-related genes in cell culture and in vivo modeling of tendon injury clearly revealed that the highly oriented nanofibrils in the FAT substantially promoted the expression of tendon-related genes combined with the Achilles tendon structure and function. These results provide confidence about the potential clinical applications of the FAT.
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Engenharia Tecidual , Alicerces Teciduais , Alicerces Teciduais/química , Engenharia Tecidual/métodos , Regeneração , Tendões , Seda/químicaRESUMO
Due to the limited self-repairing capacity after peripheral nerve injuries (PNI), artificial nerve conduits are widely applied to facilitate neural regeneration. Exogenous electrical stimulation (ES) that is carried out by the conductive conduit regulates the biological behavior of Schwann cells (SCs). Meanwhile, a longitudinal surface structure counts to guide axonal growth to accelerate the end-to-end connection. Currently, there are no conduits equipped with both electrical conduction and axon-guiding surface structure. Herein, a biodegradable, conductive poly(l-lactide-co-caprolactone)/graphene (PLCL/GN) composite conduit is designed. The conduit with 20.96 ± 1.26 MPa tensile strength has a micropatterned surface of 20 µm groove fabricated by microimprint technology and self-assembled polydopamine (PDA). In vitro evaluation shows that the conduits with ES effectively stimulate the directional cell migration, adhesion, and elongation, and enhance neuronal expression of SCs. The rat sciatic nerve crush model demonstrates that the conductive micropatterned conduit with ES promotes the growth of myelin sheath, faster nerve regeneration, and 20-fold functional recovery in vivo. These discoveries prove that the PLCL(G)/PDA/GN composite conduit is a promising tool for PNI treatment by providing the functional integration of physical guidance, biomimetic biological regulation, and bioelectrical stimulation, which inspires a novel therapeutic approach for nerve regeneration in the future.
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Traumatismos dos Nervos Periféricos , Polímeros , Ratos , Animais , Polímeros/química , Nervo Isquiático/lesões , Nervo Isquiático/fisiologia , Indóis/farmacologia , Regeneração Nervosa/fisiologiaRESUMO
The electrical microenvironment plays an important role in bone repair. However, the underlying mechanism by which electrical stimulation (ES) promotes bone regeneration remains unclear, limiting the design of bone microenvironment-specific electroactive materials. Herein, by simple co-incubation in aqueous suspensions at physiological temperatures, biocompatible regenerated silk fibroin (RSF) is found to assemble into nanofibrils with a ß-sheet structure on MXene nanosheets, which has been reported to inhibit the restacking and oxidation of MXene. An electroactive hydrogel based on RSF and bioencapsulated MXene is thus prepared to promote efficient bone regeneration. This MXene/RSF hydrogel also acts as a piezoresistive pressure transducer, which can potentially be utilized to monitor the electrophysiological microenvironment. RNA sequencing is performed to explore the underlying mechanisms, which can activate Ca2+/CALM signaling in favor of the direct osteogenesis process. ES is found to facilitate indirect osteogenesis by promoting the polarization of M2 macrophages, as well as stimulating the neogenesis and migration of endotheliocytes. Consistent improvements in bone regeneration and angiogenesis are observed with MXene/RSF hydrogels under ES in vivo. Collectively, the MXene/RSF hydrogel provides a distinctive and promising strategy for promoting direct osteogenesis, regulating immune microenvironment and neovascularization under ES, leading to re-establish electrical microenvironment for bone regeneration.
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Circadian rhythm (CR) disruption contributes to tumor initiation and progression, however the pharmacological targeting of circadian regulators reversely inhibits tumor growth. Precisely controlling CR in tumor cells is urgently required to investigate the exact role of CR interruption in tumor therapy. Herein, based on KL001, a small molecule that specifically interacts with the clock gene cryptochrome (CRY) functioning at disruption of CR, we fabricated a hollow MnO2 nanocapsule carrying KL001 and photosensitizer BODIPY with the modification of alendronate (ALD) on the surface (H-MnSiO/K&B-ALD) for osteosarcoma (OS) targeting. The H-MnSiO/K&B-ALD nanoparticles reduced the CR amplitude in OS cells without affecting cell proliferation. Furthermore, nanoparticles-controlled oxygen consumption by inhibiting mitochondrial respiration via CR disruption, thus partially overcoming the hypoxia limitation for photodynamic therapy (PDT) and significantly promoting PDT efficacy. An orthotopic OS model demonstrated that KL001 significantly enhanced the inhibitory effect of H-MnSiO/K&B-ALD nanoparticles on tumor growth after laser irradiation. CR disruption and oxygen level enhancement induced by H-MnSiO/K&B-ALD nanoparticles under laser irradiation were also confirmed in vivo. This discovery first demonstrated the potential of CR controlling for tumor PDT ablation and provided a promising strategy for overcoming tumor hypoxia.
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The bone matrix has distinct architecture and biochemistry which present a barrier to synthesizing bone-mimetic regenerative scaffolds. To mimic the natural structures and components of bone, biomimetic structural decellularized extracellular matrix (ECM)/regenerated silk fibroin (RSF) scaffolds incorporated with magnetic nanoparticles (MNP) are prepared using a facile synthetic methodology. The ECM/RSF/MNP scaffold is a hierarchically organized and interconnected porous structure with silk fibroin twined on the collagen nanofibers. The scaffold demonstrates saturation magnetization due to the presence of MNP, along with good cytocompatibility. Moreover, the ß-sheet crystalline domain of RSF and the chelated MNP could mimic the deposition of hydroxyapatite and enhance compressive modulus of the scaffold by ≈20%. The results indicate that an external static magnetic field (SMF) with a magnetic responsive scaffold effectively promotes cell migration, osteogenic differentiation, neogenesis of endotheliocytes in vitro, and new bone formation in a critical-size femur defect rat model. RNA sequencing reveals that the molecular mechanisms underlying this osteogenic effect involve calsequestrin-2-mediated Ca2+ release from the endoplasmic reticulum to activate Ca2+ /calmodulin/calmodulin-dependent kinase II signaling axis. Collectively, bionic magnetic scaffolds with SMF stimulation provide a potent strategy for bone regeneration through internal structural cues, biochemical composition, and external physical stimulation on intracellular Ca2+ homeostasis.
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Fibroínas , Alicerces Teciduais , Ratos , Animais , Alicerces Teciduais/química , Fibroínas/química , Osteogênese , Cálcio , Biomimética , Calmodulina , Regeneração Óssea/fisiologia , Fenômenos Magnéticos , Engenharia Tecidual/métodosRESUMO
Innate and adaptive immunity is important for initiating and maintaining immune function. The nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome serves as a checkpoint in innate and adaptive immunity, promoting the secretion of pro-inflammatory cytokines and gasdermin D-mediated pyroptosis. As a highly inflammatory form of cell death distinct from apoptosis, pyroptosis can trigger immunogenic cell death and promote systemic immune responses in solid tumors. Previous studies proposed that NLRP3 was activated by translocation to the mitochondria. However, a recent authoritative study has challenged this model and proved that the Golgi apparatus might be a prerequisite for the activation of NLRP3. In this study, we first developed a Golgi apparatus-targeted photodynamic strategy to induce the activation of NLRP3 by precisely locating organelles. We found that Golgi apparatus-targeted photodynamic therapy could significantly upregulate NLRP3 expression to promote the subsequent release of intracellular proinflammatory contents such as IL-1ß or IL-18, creating an inflammatory storm to enhance innate immunity. Moreover, this acute NLRP3 upregulation also activated its downstream classical caspase-1-dependent pyroptosis to enhance tumor immunogenicity, triggering adaptive immunity. Pyroptosis eventually led to immunogenic cell death, promoted the maturation of dendritic cells, and effectively activated antitumor immunity and long-lived immune memory. Overall, this Golgi apparatus-targeted strategy provided molecular insights into the occurrence of immunogenic pyroptosis and offered a platform to remodel the tumor microenvironment.
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Proteína 3 que Contém Domínio de Pirina da Família NLR , Piroptose , Inflamassomos/metabolismo , Imunidade Inata , Complexo de Golgi/metabolismo , Interleucina-1beta , Caspase 1/metabolismoRESUMO
Narrowing the mechanical and electrical mismatch between tissue and implantable microelectronics is essential for reducing immune responses and modulating physioelectrical signals. Nevertheless, the design of such implantable microelectronics remains a challenge due to the limited availability of suitable materials. Here, the fabrication of an electrically and mechanically biocompatible alginate hydrogel ionotronic fiber (AHIF) is reported, which is constructed by combing ionic chelation-assisted wet-spinning and mechanical training. The synergistic effects of these two processes allow the alginate to form a highly-oriented nanofibril and molecular network, with a hierarchical structure highly similar to that of natural fibers. These favourable structural features endow AHIF with tissue-mimicking mechanical characteristics, such as self-stiffening and soft tissue-like mechanical properties. In addition, tissue-like chemical components, i.e., biomacromolecules, Ca2+ ions, and water, endow AHIF with properties including biocompatibility and tissue-matching conductivity. These advantages bring light to the application of AHIFs in electrically-conductive implantable devices. As a prototype, an AHIF is designed to perform physioelectrical modulation through noncontact electromagnetic induction. Through experimental and machine learning optimizations, physioelectrical-like signals generated by the AHIF are used to identify the geometry and tension state of the implanted device in the body. Such an intelligent AHIF system has promising application prospects in bioelectronics, IntelliSense, and human-machine interactions.
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Eletricidade , Hidrogéis , Alginatos/química , Condutividade Elétrica , Humanos , Hidrogéis/química , Íons/químicaRESUMO
Poor immunogenicity and compromised T cell infiltration impede the application of immune-checkpoint blockade (ICB) immunotherapy for osteosarcoma (OS). Although autophagy is involved in enhancing the immune response, the synergistic role of autophagy in ICB immunotherapy and the accurate control of autophagy levels in OS remain elusive and challenging. Here, we designed a pH-sensitive autophagy-controlling nanocarrier, CUR-BMS1166@ZIF-8@PEG-FA (CBZP), loading a natural derivative, curcumin (CUR), to boost the immunotherapeutic response of PD-1/PD-L1 blockade by activating immunogenic cell death (ICD) via autophagic cell death, and BMS1166 to inhibit the PD-1/PD-L1 interaction simultaneously, enhancing the tumor immunogenicity and sensitizing the antitumor T cell immunity. After entering tumor cells, the pH-sensitive nanoparticles induced autophagy and decreased the intracellular pH, which in turn further facilitated the release of CUR to enhance autophagic activity. Transferring CBZP to orthotopic OS tumor-bearing mice showed powerful antitumor effects and established long-term immunity against tumor recurrence, accompanied by enhanced dendritic cell maturation and tumor infiltration of CD8+ T lymphocytes. Collectively, CBZP exhibited synergistic effects in treating OS by combining ICD induction with checkpoint blockade, thereby shedding light on the use of autophagy control as a potential clinical therapy for OS.
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Neoplasias Ósseas , Estruturas Metalorgânicas , Osteossarcoma , Animais , Autofagia , Antígeno B7-H1/metabolismo , Neoplasias Ósseas/terapia , Linhagem Celular Tumoral , Inibidores de Checkpoint Imunológico , Imunoterapia , Camundongos , Recidiva Local de Neoplasia , Osteossarcoma/terapia , Receptor de Morte Celular Programada 1 , Microambiente TumoralRESUMO
Background: After peripheral nerve injury, Schwann cells proliferate and migrate to the injured site, thereby promoting peripheral nerve regeneration. The process is regulated by various factors. Endothelial cells participate in the process via angiogenesis. However, the effects of endothelial cells on Schwann cells are not yet known. The present study sought to evaluate whether endothelial cells accelerate Schwann cell proliferation and migration. Methods: We established a co-culture model of rat Schwann cells (RSC96s) and rat aortic endothelial cells (RAOECs), and studied the effects of endothelial cells on Schwann cells by evaluating changes in Schwann cell proliferation and migration and related multiple genes and their protein expressions in the co-culture model. Results: The results showed that increasing the proportion of endothelial cells in the co-culture model enhanced the proliferation. At days 1 and 3 following the co-culturing, the relative growth rates of the co-cultured cells were 122.87% and 127.37%, respectively, which showed a significant increase in the viability compared to that of the RSC96s (P<0.05). In this process, the expression of Ki67 increased. The migration ability of Schwann cells was also enhanced. The migration capacity of Schwann cells was detected by wound-healing and Transwell assays. The results of the group with 15% of endothelial cells was significantly higher than the results of the other groups (P<0.0001 and P<0.05, respectively). Further, neuregulin 1 and glial fibrillary acidic protein increased the process of Schwann cell migration. Conclusions: The results showed that endothelial cells can promote the proliferation and migration of Schwann cells and participate in peripheral nerve regeneration.
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Although autophagy may be beneficial for maintaining the metabolic balance of the extracellular matrix (ECM) in the nucleus pulposus (NP) and its vitality under inflammation, the underlying mechanism still remains unclear. A previous study found that autophagy activation stimulated the release of exosomes in normal chondrocytes, which are located in a similar avascular environment and share many common features with those of nucleus pulposus cells (NPCs). This study explored the protective effect on matrix degradation in the NP by exosomes derived from autophagy-activated NPCs and exosomal microRNAs. NPCs-derived exosomes (NPCs-Exos) were isolated from culture medium of either normal NPCs or rapamycin-treated NPCs and quantified by nanoparticle tracking analysis. The effect of rapamycin-treated NPC-derived exosomes on NPCs were assessed by coculture with interleukin 1ß (IL-1ß)-stimulated NPCs. After examination of six major proteinases of the ECM, matrix metalloproteinase 13 (MMP-13) was chosen for further study. miR-27a, which targets MMP-13, was investigated through previous studies and bioinformatics tool. The levels of miR-27a were upregulated in both rapamycin-treated NPCs and their exosomes, compared to the control. When exosomal miR-27a was transferred into NPCs, it alleviated IL-1ß-induced degradation of the NPC ECM by targeting MMP-13. Autophagy activation may promote the release of NPCs-derived exosomes and thereby prevent the NPC matrix from degradation. Autophagy activation also alleviates intervertebral disc degeneration (IDD), at least partly via exosomal miR-27a, which restrains MMP-13 expression under IL-1ß stimulation. Our work elucidates a new mechanism for how autophagy may participate in preventing IDD, which may be a promising therapeutic strategy.