Membrane Particles Research Articles

Extraction and Biological Evaluation of Matrix-Bound Nanovesicles (MBVs) from High-Hydrostatic Pressure-Decellularized Tissues.

Decellularized tissues are widely used as promising materials in tissue engineering and regenerative medicine. Research on the microstructure and components of the extracellular matrix (ECM) was conducted to improve the current understanding of decellularized tissue functionality. The presence of matrix-bound nanovesicles (MBVs) embedded within the ECM was recently reported. Results of a previous experimental investigation revealed that decellularized tissues prepared using high hydrostatic pressure (HHP) exhibited good in vivo performance. In the current study, according to the hypothesis that MBVs are one of the functional components in HHP-decellularized tissue, we investigated the extraction of MBVs and the associated effects on vascular endothelial cells. Using nanoparticle tracking assay (NTA), transmission electron microscopy (TEM), and RNA analysis, nanosized (100–300 nm) and membranous particles containing small RNA were detected in MBVs derived from HHP-decellularized small intestinal submucosa (SIS), urinary bladder matrix (UBM), and liver. To evaluate the effect on the growth of vascular endothelial cells, which are important in the tissue regeneration process, isolated SIS-derived MBVs were exposed to vascular endothelial cells to induce cell proliferation. These results indicate that MBVs can be extracted from HHP-decellularized tissues and may play a significant role in tissue remodeling.

Mass under the Membrane Theory of Gravitation

The Cosmic Membrane theory of gravitation (CM) implies Newton’s absolute space. We identify the homogeneous vector field used by us since 1994 with the Higgs-field as source of the heavy mass. Following Randall and Sundrum, the introduction of the wafting layer outside the membrane solves the issue of the mobility of particles in a super-strong membrane. Starting with Feynman’s radius of excess, we obtain a depth of space of WRS = 1.432×106 [m] of the gravitational funnel at the edge of sun. Using Chandrasekhar’s gravitational energy, we obtain the tension F0 of the membrane as F0=1.820×1019 [N/m2], and the vertical vector field acceleration AVFV, acting perpendicularly from the fourth spatial dimension on the membrane, with AVFV=1.148×105 [m/s2]. The horizontal vector field acceleration AVFH, i.e., inside the wafting layer, is AVFH=1.330×105 [m/s2], and acts as acceleration a=AVFH w’ with w’ the being slope of the membrane. The mass of the moved membrane in a moving gravitational funnel behaves as an inert mass, but yields a numerical value that is too small to explain the equivalence of heavy and inert mass. Assuming speed of light c for transversal gravitational waves, we obtain a first estimation of the mass distribution ρsurf of the membrane. The clay lump model of the relativistic increase of mass follows the assumption that the energy of the accelerating photons will act again half as mass and half as kinetic energy at the accelerated particle. Our result equals exactly Einstein’s SR result.

Emergence of Edible Plant-Derived Nanovesicles as Functional Food Components and Nanocarriers for Therapeutics Delivery: Potentials in Human Health and Disease.

Extracellular vesicles (EVs) are a highly heterogeneous population of membranous particles that are secreted by almost all types of cells across different domains of life, including plants. In recent years, studies on plant-derived nanovesicles (PDNVs) showed that they could modulate metabolic reactions of the recipient cells, affecting (patho)physiology with health benefits in a trans-kingdom manner. In addition to its bioactivity, PDNV has advantages over conventional nanocarriers, making its application promising for therapeutics delivery. Here, we discuss the characteristics of PDNV and highlight up-to-date pre-clinical and clinical evidence, focusing on therapeutic application.

Plant extracellular vesicles and their potential in human health research, the practical approach.

Extracellular vesicles are small membrane particles (30-1000 nm) released by Bacteria, Eukaryotes and Archaea. They have been shown to play an important role in intracellular and intercellular communication, within and between kingdoms via transport of bioactive molecules. Thus, they can be involved in altering gene expression and regulation of physiological and pathological processes of the recipient. Their unique properties make extracellular vesicles a perfect candidate vector for targeted drug delivery or a biomarker. For a long time, animal and mainly mammal extracellular vesicles have been used in research. But for plants, there had been speculations about the existence of nanovesicles due to the presence of a cell wall. Today, awareness of plant extracellular vesicles is on the rise and their research has proved they have various functions, such as protein secretion, transport of bioactive molecules or defense against pathogens. Further potential of plant extracellular vesicles is stressed in this review.

Extracellular vesicles: Emerging frontiers in wound healing.

Extracellular vesicles are membranous particles, ranging from 30 nm to 10 µm in diameter, which are released by nearly all cell types to aid in intercellular communication. These complex vesicles carry a multitude of signaling moieties from their cell of origin, such as proteins, lipids, cell surface receptors, enzymes, cytokines, metabolites, and nucleic acids. A growing body of evidence suggests that in addition to delivering cargos into target cells to facilitate intercellular communication, extracellular vesicles may also play roles in such processes as cell differentiation and proliferation, angiogenesis, stress response, and immune signaling. As these vesicles have natural biocompatibility, stability in circulation, low toxicity, and low immunogenicity, and serve as efficient carriers of molecular cargos, these nanoparticles are ideal therapeutic candidates for regenerative medicine. Exploring and identifying the homeostatic functions of extracellular vesicles may facilitate the development of new regenerative therapies. In this review, we summarize the wound healing process, difficulties in stem cell therapies for regenerative medicine, and the applications of mesenchymal stromal cell-derived extracellular vesicles in improving and accelerating the wound healing process.

The encephalomyocarditis virus Leader promotes the release of virions inside extracellular vesicles via the induction of secretory autophagy

Naked viruses can escape host cells before the induction of lysis via release in extracellular vesicles (EVs). These nanosized EVs cloak the secreted virus particles in a host-derived membrane, which alters virus-host interactions that affect infection efficiency and antiviral immunity. Currently, little is known about the viral and host factors regulating this form of virus release. Here, we assessed the role of the encephalomyocarditis virus (EMCV) Leader protein, a ‘viral security protein’ that subverts the host antiviral response. EV release upon infection with wildtype virus or a Leader-deficient mutant was characterized at the single particle level using high-resolution flow cytometry. Inactivation of the Leader abolished EV induction during infection and strongly reduced EV-enclosed virus release. We demonstrate that the Leader promotes the release of virions within EVs by stimulating a secretory arm of autophagy. This newly discovered role of the EMCV Leader adds to the variety of mechanisms via which this protein affects virus-host interactions. Moreover, these data provide first evidence for a crucial role of a non-structural viral protein in the non-lytic release of picornaviruses via packaging in EVs.

Therapeutic Strategy of Mesenchymal-Stem-Cell-Derived Extracellular Vesicles as Regenerative Medicine.

Extracellular vesicles (EVs) are lipid bilayer membrane particles that play critical roles in intracellular communication through EV-encapsulated informative content, including proteins, lipids, and nucleic acids. Mesenchymal stem cells (MSCs) are pluripotent stem cells with self-renewal ability derived from bone marrow, fat, umbilical cord, menstruation blood, pulp, etc., which they use to induce tissue regeneration by their direct recruitment into injured tissues, including the heart, liver, lung, kidney, etc., or secreting factors, such as vascular endothelial growth factor or insulin-like growth factor. Recently, MSC-derived EVs have been shown to have regenerative effects against various diseases, partially due to the post-transcriptional regulation of target genes by miRNAs. Furthermore, EVs have garnered attention as novel drug delivery systems, because they can specially encapsulate various target molecules. In this review, we summarize the regenerative effects and molecular mechanisms of MSC-derived EVs.

Chitosan-modified geopolymer sub-microparticles reinforced multifunctional membrane for enhanced removal of multiple contaminants in water

Nanoparticle-reinforced membranes have received widespread interest in water purification; however, their application is limited due to high cost, harsh conditions, and strong tendency of nanoparticles agglomeration and leaching. Herein, a multifunctional membrane was newly created by filling the pores of a glass fiber microfiltration membrane (GF) with chitosan-modified geopolymer sub-microparticles (CS-GMs) and crosslinking with polydopamine. Characterizations revealed that the introduction of CS-GMs was successful in regulating the porous structure of the membrane and suppressing membrane thickness growth and particle agglomeration. With an optimal dose of CS-GMs (0.45 g), the screening pore size of the membrane was regulated to 58 nm, thus showing a high rejection rate for microplastics (89.37%). In addition, the membrane was super-hydrophilic/underwater super-oleophobic and superior to the documented nanoparticle-reinforced membranes in decontaminating different oil-in-water emulsions (>99.5%) and co-existing pollutants (n-hexadecane: 99.62%, crystal violet: 94.51%, and lead ions: 99.62%) due to the effects of sieving and adsorption. Moreover, it possessed good reusability, rational environmental tolerance, long-term operational stability and point-of-use functions. Overall, this study paves the way for the feasible creation of low-cost, eco-friendly, and multifunctional sub-microparticle-reinforced membranes for the effective elimination of multiple contaminants in wastewater.

Membrane particles evoke a serotype-independent cross-protection against pneumococcal infection that is dependent on the conserved lipoproteins MalX and PrsA

Pneumococcal conjugate vaccines (PCVs) used in childhood vaccination programs have resulted in replacement of vaccine-type with nonvaccine-type pneumococci in carriage and invasive pneumococcal disease (IPD). A vaccine based on highly conserved and protective pneumococcal antigens is urgently needed. Here, we performed intranasal immunization of mice with pneumococcal membrane particles (MPs) to mimic natural nasopharyngeal immunization. MP immunization gave excellent serotype-independent protection against IPD that was antibody dependent but independent of the cytotoxin pneumolysin. Using Western blotting, immunoprecipitation, mass spectrometry, and different bacterial mutants, we identified the conserved lipoproteins MalX and PrsA as the main antigens responsible for cross-protection. Additionally, we found that omitting the variable surface protein and vaccine candidate PspA from MPs enhanced protective immune responses to the conserved proteins. Our findings suggest that MPs containing MalX and PrsA could serve as a platform for pneumococcal vaccine development targeting the elderly and immunocompromised.

Molecular and structural design of polyacrylonitrile-based membrane for oil-water separation

Herein, a durable superhydrophobic/superoleophilic membrane with micro-/nano-hierarchical structure was achieved through molecular and structural design of fluorinated polyacrylonitrile-based membrane. In which, the introduction of perfluorooctanol acrylate into copolymer chain and usage of electrospinning/electrospraying technology followed by heat post-treatment provided low surface energy and durable hierarchical structure, respectively. The resultant membrane demonstrated superhydrophobicity and superoleophilicity with water contact angle of 160° and oil contact angle of 0° in air, which endowed the membrane with excellent separation ability for oil/water mixture with separation efficiency above 99% and ultrahigh flux beyond 8000 L/m 2 /h. Furthermore, the obtained membrane maintained its superhydrophobicity after exposure to broad pH, organic solvents, high temperature and ultrasonic treatment, ascribed to the chemical reaction of cyano groups on the surface of fibers and particles during the heat post-treatment. This work provides a promising strategy to fabricate superwetting membrane to remove trace amount of water in oil. A durable and robust membrane with micro-/nano-hierarchical structure was achieved through molecular and structural design of polyacrylonitrile-based membrane for efficient separation of various oil/water mixtures. • A novel fluorinated polyacrylonitrile copolymer was synthesized. • Membrane with micro-/nano-scale structures was constructed by using the copolymer. • The fibers and particles in membrane were integrated by chemical interactions. • Durable superhydrophobicity of membrane was achieved. • The membrane showed excellent separation efficiency for oily wastewater.

Bipolar Metal Flexible Electrospun Fibrous Membrane Based on Metal–Organic Framework for Gradient Healing of Tendon‐to‐Bone Interface Regeneration (Adv. Healthcare Mater. 12/2022)

Bioscaffolds This schematic diagram is to illustrate the repair effect of a bipolar fibrous membrane in the ink painting style with Chinese characteristics. The sky and ground on both sides of the fibrous membrane respectively represents tendon and bone. Both the MOF particles in the bipolar fibrous membrane can promote tissue repair, and the phoenix is used to highlight the repair effect of MOF particles. This work can be found in article number 2200072 by Wenguo Cui, Yao Chen, Lei Wang, and co-workers.

The M13 Phage Assembly Machine Has a Membrane-Spanning Oligomeric Ring Structure.

Bacteriophage M13 assembles its progeny particles in the inner membrane of the host. The major component of the assembly machine is G1p and together with G11p it generates an oligomeric structure with a pore-like inner cavity and an ATP hydrolysing domain. This allows the formation of the phage filament, which assembles multiple copies of the membrane-inserted major coat protein G8p around the extruding single-stranded circular DNA. The phage filament then passes through the G4p secretin that is localized in the outer membrane. Presumably, the inner membrane G1p/G11p and the outer G4p form a common complex. To unravel the structural details of the M13 assembly machine, we purified G1p from infected E. coli cells. The protein was overproduced together with G11p and solubilized from the membrane as a multimeric complex with a size of about 320 kDa. The complex revealed a pore-like structure with an outer diameter of about 12 nm, matching the dimensions of the outer membrane G4p secretin. The function of the M13 assembly machine for phage generation and secretion is discussed.

αvβ3-targeted sEVs for efficient intracellular delivery of proteins using MFG-E8

BackgroundSmall extracellular vesicles (sEVs) are nanometer-sized membranous particles shed by many types of cells and can transfer a multitude of cargos between cells. Recent studies of sEVs have been focusing on their potential to be novel drug carriers due to natural composition and other promising characteristics. However, there are challenges in sEVs-based drug delivery, one of which is the inefficient loading of drugs into sEVs, especially for large biomolecules.ResultsIn this study, we proposed a membrane-associated protein, milk fat globule–epidermal growth factor 8 protein (MFG-E8), to produce αvβ3-targeted sEVs with high delivery efficiency of interested protein. MFG-E8 is a secreted protein with NH2-terminal epidermal growth factor (EGF)–like domains, containing an Arg-Gly-Asp(RGD) sequence that binds αvβ3 and αvβ5 integrins, and COOH terminal domains C1 and C2, which can bind to lipid membrane with strong affinity. Firstly, we transiently expressed MFG-E8 in HEK293F cells and found that this protein could be secreted and adhere to the cell membrane. The recombinant MFG-E8 is also found to locate at the outer membrane of sEVs. Then we generated engineered sEVs by expressing high levels of the EGFP fused to MFG-E8 in HEK293F cells and showed that MFG-E8 could increase the delivery efficiency of EGFP into sEVs. Further delivery of Gaussia luciferase (GL) by fusion expression with MFG-E8 in donor cells demonstrated that target proteins fused with MFG-E8 still kept their activity. Finally, we identified the sEVs’ target to integrin αvβ3 by comparing the transfection efficiency with MFG-E8 loaded sEVs (MFG-E8-sEVs) in αvβ3 positive cells and αvβ3 negative cells. Analysis showed higher target protein could transfect into αvβ3 positive cells with MFG-E8-sEVs than with EGFP loaded sEVs (EGFP-sEVs), meaning the engineered sEVs with MFG-E8 not only could increase the delivery of target protein into sEVs, but also could target the αvβ3 positive cells.ConclusionThis study suggests that recombinant MFG-E8 is an ideal protein to increasingly deliver the drug into sEVs and give sEVs the ability to target the αvβ3 positive cells.

Zebrafish Melanoma-Derived Interstitial EVs Are Carriers of ncRNAs That Induce Inflammation.

Extracellular vesicles (EVs) are membranous particles released by all cell types. Their role as functional carrier of bioactive molecules is boosted by cells that actively secrete them in biological fluids or in the intercellular space (interstitial EVs, iEVs). Here we have optimised a method for the isolation and characterization of zebrafish iEVs from whole melanoma tissues. Zebrafish melanoma iEVs are around 140 nm in diameter, as determined by nanoparticle tracking and transmission electron microscopy (TEM) analysis. Western blot analysis shows enrichment for CD63 and Alix in the iEV fraction, but not in melanoma cell lysates. Super resolution and confocal microscopy reveal that purified zebrafish iEVs are green fluorescent protein positive (GFP+), indicating that they integrate the oncogene GFP-HRASV12G used to induce melanoma in this model within their vesicular membrane or luminal content. Analysis of RNA-Seq data found 118 non-coding (nc)RNAs differentially distributed between zebrafish melanoma and their iEVs, with only 17 of them being selectively enriched in iEVs. Among these, the RNA components of RNAses P and MRP, which process ribosomal RNA precursors, mitochondrial RNAs, and some mRNAs, were enriched in zebrafish and human melanoma EVs, but not in iEVs extracted from brain tumours. We found that melanoma iEVs induce an inflammatory response when injected in larvae, with increased expression of interferon responsive genes, and this effect is reproduced by MRP- or P-RNAs injected into circulation. This suggests that zebrafish melanoma iEVs are a source of MRP- and P-RNAs that can trigger inflammation in cells of the innate immune system.

Small extracellular vesicles induced gene expression changes in microglia

BackgroundSmall extracellular vesicles (sEVs) are 30‐150 nm membranous particles released by a variety of cells and serve as a mediator in intercellular communication between adjacent and distal cells. sEVs carry biomolecular cargo including miRNAs, mRNAs, proteins, and lipids, which are selectively sorted and packaged and mirror the physiological state of the donor cells. Disease states can alter sEV composition affecting the message carried and thereby, its functional impact. Microglia, as the tissue‐resident macrophages and primary innate immune cells of the central nervous system, play an important role in neuropathic pain. Here, we investigated alterations in the composition of serum sEVs from a mouse model of neuropathic pain and assessed the functional consequences of sEV uptake by primary cortical microglia.MethodssEVs were purified from the serum of a spared nerve injury (SNI) mouse model of neuropathic pain and sham‐operated mice four weeks after surgery. sEV uptake by primary cortical microglia was confirmed by incubating microglia with 1 µg of PKH26‐labeled sEVs for 24 h and visualized using confocal microscopy. Transcriptome and cytokine alterations induced by sEV uptake in microglia (1 µg for 24 h) were determined using RNA‐seq and cytokine array.ResultsWe identified a differential expression of 22 miRNAs in serum sEVs derived from SNI and sham control mice. Confocal microscopy confirmed the presence of sEVs in microglia following 24 h sEV incubation. We observed a significant difference in gene expression resulting from the uptake of distinct serum sEVs – alterations were more prominent in microglia treated with sham sEVs. Gene Ontology analysis indicated gene expression changes induced by the uptake of sEVs from both SNI and sham surgery were both implicated in immune responses, but genes upregulated by sham sEVs were also enriched in inflammatory responses. Secretions of pro‐inflammatory cytokines and chemokines including CXCL10, CXCL2, and TNF‐α were higher in microglia incubated with sEVs from mice that had sham surgery compared to PBS control or SNI sEVs.ConclusionsOur data demonstrate alterations in sEV composition from both SNI and sham surgeries, and the molecular changes captured in donor sEVs could impact gene expression in the recipient cells. The differences observed in microglial phenotypes and gene expression suggest sEVs from sham surgery are directed at wound healing and thus differ from nerve injury‐induced sEVs.

The Relation Between Extracellular Vesicles Released From Red Blood Cells, Their Cargo, and the Clearance by Macrophages.

Extracellular vesicles (EVs) are cell-derived membrane particles that include exosomes, ectosomes, microvesicles, microparticles, apoptotic bodies, and other EV subsets. EVs are involved in intercellular communication and the transport of macromolecules between cells. Here, we propose and test the ability of red blood cell (RBC)-derived EVs (RBC-EVs) as putative drug carriers. EVs were produced by treating RBCs with Phorbol-12-myristate-13-acetate (PMA) and separating from the cells by differential centrifugation steps. RBC-EVs were characterized by size determination, flow cytometry, and scanning electron microscopy (SEM). EVs were loaded with DNA plasmids coding for the green fluorescent protein (GFP) by electroporation. The DNA-loaded EVs (DNA-EVs) were used to transfect THP-1-derived macrophages and analyzed by fluorescence microscopy and flow cytometry. The results showed that RBC-EVs had an almost spherical shape and a polydispersity in their size with an average of 197 ± 44 nm and with a zeta potential of −36 ± 8 mV. RBC-EVs were successfully loaded with DNA but associated with an increase of the polydispersity index (PdI) and showed a positive signal with Picogreen. DNA-EVs were almost completely taken up by macrophages within 24 h, however, resulting in the expression of the GFP in a subpopulation of macrophages. As the way, we designed that RBC-EVs could be potential nucleic acid carriers when the immune system was addressed. This study may contribute to the understanding of the role of EVs in the development of microvesicle-based vehicles.

Investigation of fluoride and silica removal from semiconductor wastewaters with a clean coagulation-ultrafiltration process

Fluoride and silica contamination in water is a worldwide issue due to the wastewater discharge from semiconductor industry. Coagulation-ultrafiltration (UF) process is commonly used to treat semiconductor wastewaters, but it requires excessive amounts of coagulant/flocculant. In this study, a clean coagulation-UF process using chemical mechanical polishing (CMP) wastewater as a coagulant to treat fluoride-containing wastewater was firstly proposed. The fluoride-containing wastewater, CMP wastewater, mixed fluoride-containing wastewater and CMP wastewater, and mixed fluoride-containing wastewater and polyaluminium chloride/polyacrylamide were compared to investigate turbidity removal efficiency, fluoride removal efficiency and membrane fouling resistance. The negatively charged SiO2 particles in CMP wastewater were found to be adsorbed on the positively charged CaF2 particles surface through electrostatic interaction. Results indicated that CMP wastewater provided a superior turbidity removal efficiency and a minimal membrane fouling resistance compared to conventional coagulant. After UF filtration, the fluoride concentration and turbidity were 2.09 mg L−1 and 0 NTU, respectively, which met the median fluoride effluent standard. The extended Derjaguin-Landau-Verwey-Overbeek theory showed that increasing molar ratio of SiO2 to CaF2 improved the interfacial free energy between membrane and suspended particles, thus mitigating membrane fouling. This clean design principle and strategy will broaden the sustainability of coagulation-UF process for wastewater treatment.

The Ti-Mesh Technique: Guided Bone Regeneration for Three-Dimensional Augmentations. Clinical Aspects: A Case Series.

This article presents the surgical aspects of, and evaluates bone dimensional changes following, the application of the guided bone regeneration (GBR) technique using individualized titanium mesh on atrophied alveolar ridges to achieve an optimal crest volume for implant placement. Six patients were included and evaluated clinically and radiologically for at least 3 years. Every patient presented bone resorption affecting implant placement in a proper prosthetic position. During the regenerative procedure, customized titanium mesh was used to secure the contour of the augmented site and the stability of xenograft particles deposited on the atrophied crest. After 6 months of healing, the mesh was removed, and implants were placed in planned, prosthetic positions. CBCT scans were taken before the regenerative procedures and after 6 months, before the second-stage surgeries. This allowed for assessment of the postaugmentation vertical and horizontal bone tissue gain. The average volumetric gain of the augmented sites was 5.2 mm horizontally and 2.75 mm vertically. In 50% of cases, minor soft tissue perforation was observed after a few weeks. This complication did not influence the implant placement procedure and was treated during the second-stage procedure with the GBR technique, using a resorbable membrane and xenograft particles to compensate the localized bone defect. No implant failed during the control period. Panoramic radiographs were taken 1 to 3 years after completion of definitive prosthetic treatment to assess potential bone resorption around implants. No crestal bone resorption was observed within this period. It can be concluded that the use of customized titanium mesh is a predictable technique for bone regeneration in advanced, three-dimensional defects.

Formation and characterization of Pt-Cu-IPMC with high specific surface area and dendritic electrode

ABSTRACT Ionic polymer–metal composite (IPMC) is a kind of electroactive intelligent material. The dendritically interfacial electrodes (DIEs) is very important to the performance of IPMC. Herein, the copper–platinum composite electrode (Pt-Cu-IPMC) with a high specific area DIEs was prepared by combining impregnation-reduction plating platinum (IRP-Pt), autocatalytic plating platinum (ACP-Pt) and chemical reduction plating copper (CRP-Cu). The effects of DIEs and the cycles of ACP-Pt have been systematically investigated on the electrode’s thickness, micro-morphology and electromechanical response characteristics of all samples. Importantly, when the cycles of ACP-Pt increases, the platinum and copper particles in the ionomer membrane are highly dispersed. For example, when the cycles of ACP-Pt is 4, the penetration depth of the DIEs reaches 31.98 µm. Thus, copper and platinum dendrites were clearly observed in the samples. Combined with the analysis of the strain energy density, it showed that the presence of DIEs has some impact on the driving performance of the IPMC, the tip displacement, and blocking force of 67.27 mm and 27.21 mN have been achieved in the Pt-Cu-IPMC after three cycles of ACP-Pt.

Remifentanil Anesthesia on the Expression of Apoptosis-Related Proteins Bcl-2 and Bax in Rat Myocardial Cells with Ischemia-Reperfusion Injury

Ischemia-reperfusion damage to the myocardium is inevitable. This study mainly explored the effect of remifentanil anesthesia on the expression of apoptosis-related proteins Bcl-2 and Bax in rat myocardial ischemia-reperfusion injury. Select 48 mice (n=6). First, prepare solutions of different concentrations of remifentanil. A model of ischemia-reperfusion cardiomyocytes was established, and 6 slices of tissue were taken from each specimen, and the positive cells were observed with an optical microscope and magnified 100 times. Bcl-2 and Bax were positive in the cytoplasm and yellowish-brown particles in the inner membrane. According to the distribution of positive cells, randomly select 3 clear fields of view from each part, count the number of positive cells in each field, and then take the average of the proportion of positive cells to get Bcl-2 or Bax protein-positive Index (PEI). Comparison of mRNA levels in each group: Compared with the R3 group, the ratio of the M, R1, and R2 groups increased, and the mRNA expression level of the M group increased almost 3 times, P<0.05. The results of the study show that remifentanil reduces the mortality of myocardial cells by regulating the appearance of Bcl-2 and Bax proteins, and has a certain protective effect on the rat heart during myocardial ischemia and reperfusion. There is no statistically significant difference in the protective effect of remifentanil on myocardial ischemia-reperfusion.