Publications

The latest Tunable Resistive Pulse Sensing (TRPS) and qEV Isolation publications.

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Recent Publications

Cardioprotection by remote ischemic conditioning is transferable by plasma and mediated by extracellular vesicles.

Background Remote ischemic conditioning (RIC) by brief periods of limb ischemia and reperfusion protects against ischemia–reperfusion injury. We studied the cardioprotective role of extracellular vesicles (EV)s released into the circulation after RIC and EV accumulation in injured myocardium. Methods We used plasma from healthy human volunteers before and after RIC (pre-PLA and post-PLA) to evaluate the transferability of RIC. Pre- and post-RIC plasma samples were separated into an EV enriched fraction (pre-EV + and post-EV +) and an EV poor fraction (pre-EV- and post-EV-) by size exclusion chromatography. Small non-coding RNAs from pre-EV + and post-EV + were purified and profiled by NanoString Technology. Infarct size was compared in Sprague–Dawley rat hearts perfused with isolated plasma and fractions in a Langendorff model. In addition, fluorescently labeled EVs were used to assess homing in an in vivo rat model. (ClinicalTrials.gov, number: NCT03380663) Results Post-PLA reduced infarct size by 15% points compared with Pre-PLA (55 ± 4% (n = 7) vs 70 ± 6% (n = 8), p = 0.03). Post-EV + reduced infarct size by 16% points compared with pre-EV + (53 ± 15% (n = 13) vs 68 ± 12% (n = 14), p = 0.03). Post-EV- did not affect infarct size compared to pre-EV- (64 ± 3% (n = 15) and 68 ± 10% (n = 16), p > 0.99). Three miRNAs (miR-16-5p, miR-144-3p and miR-451a) that target the mTOR pathway were significantly up-regulated in the post-EV + group. Labelled EVs accumulated more intensely in the infarct area than in sham hearts. Conclusion Cardioprotection by RIC can be mediated by circulating EVs that accumulate in injured myocardium. The underlying mechanism involves modulation of EV miRNA that may promote cell survival during reperfusion.

2021

Caracterización de partículas coloidales en el agua del suelo mediante detección sintonizable de pulsos resistivos.

The transport of colloids in soil determines the fate of pollutants, nutrients and microorganisms in the environment and the contamination of groundwater. Colloidal retention mechanisms in soils depend on complex interactions between the soil pore walls and colloids. The hypothesis of this thesis is that the interaction of the particulate colloidal pollutants with the colloids present in the soil pore water has a dramatic influence on the transport of pollutants. This is due to the fact that the filtration of colloids in the porous medium depends on the size, shape and charge of the coatings and colloidal aggregates formed between the polluting particles and the suspended soil colloids. Improving the characterization of colloidal particulate pollutants in soil water can help to explain more precisely the role of soil as a filter for pollutants. Emerging technologies in particle characterization can represent an important advance in this characterization. Specifically, the tunable resistive pulse sensing (TRPS) detection technology allows the real (non-hydrodynamic) size of individual particles to be determined with high precision in a polydisperse suspension between 40 nm and 3 micrometers, in addition to determining, also individually, their surface electrical potential. The new knowledge that this technique can provide could lead to a better understanding of the transport of particulate pollutants in the soil, which could improve the diagnosis of potential vulnerability of subsurface waters against pathogenic organisms, engineered nanoparticles and metals bound to colloids, as well as optimize the design of micro and nanopesticide formulations.

2021

Cancer-Associated Fibroblasts Exosomal miR-106a Promotes Breast Cancer Invasion and Metastasis by Down-regulation of TCEAL7

Studies have shown that cancer-associated broblasts (CAFs) play an irreplaceable role in the occurrence and development of tumors. Therefore, exploring the action and mechanism of CAFs on tumor cells is particularly important for designing new and effective treatments and improving prognosis of tumors. For exosomes have been shown to play vital roles in intercellular communication, in this study, we compared the effects of CAFs-derived exosomes and NFs-derived exosomes on breast cancer cell proliferation, migration, and metastasis. The results showed that exosomes from both CAFs and NFs could enter into breast cancer cells and CAFs-derived exosomes had a more enhancing effect on breast cancer cell proliferation and invasion than NFs-derived exosomes. Furthermore, it was found that the expression levels of miR-106a in exosomes derived from CAFs were signicantly up-regulated than that of NFsderived exosomes and what’s more, in vitro and in vivo studies have shown that miR-106a can promote breast cancer cell proliferation, migration and metastasis by specically binding to the 3'UTR of TCEAL7. It is inspiring to nd that the miR-106a-TCEAL7 pathway promotes Snail nuclear ectopic activation by activating NF-κB, thereby inducing epithelial-mesenchymal transition and promoting cell proliferation and metastasis. Moreover, a mouse xenograft model conrmed that CAFs-derived exosomes miR-106a could promote tumor metastasis. The above data shows that CAFs-derived exosomes miR-106a promote Snail nuclear ectopic by targeting TCEAL7 to activate the NF-κB pathway, thereby inducing EMT, invasion and metastasis of breast cancer. Targeting CAFs-derived exosome miR-106a may be a potential treatment option to overcome breast cancer progression.

2021

Cancer cell uptake and distribution of oxanorbornane-based synthetic lipids and their prospects as novel drug delivery systems

Innovative developments in drug delivery technologies rely on our ability to tune the properties of supramolecular and macromolecular carriers through the chemical characteristics of individual components or building-blocks. In this regard, oxanorbornane-based synthetic lipids offer great promise as novel drug delivery systems (NDDS). As part of our efforts to develop them as vehicles for anticancer drugs, we have designed and synthesized a new derivative with a fluorescent tag (NBD) on the head group, and investigated its uptake and distribution in A549 cells. Addition of its DMSO solution to aqueous phase followed by extrusion generated solid lipid particles (SLPs), which were characterized by DLS, AFM and TEM techniques. Vesicles of this lipid in a co-assembled state with phosphatidylcholine (PC) and cholesterol were also prepared by thin-film hydration method. DLS data obtained from samples suspended in PBS showed that average size of SLPs is relatively smaller (∼56 nm) than that of vesicles (∼262 nm). The zeta potential of these particles was between −45 and −51 mV, which favor stable formulations. Confocal microscopic analysis of these aggregates after incubation with A549 cells showed that they get distributed predominantly in the cytosolic side. Concentration- and time-dependent flow cytometry analysis revealed that the uptake commences in the initial 5 min itself, and almost 90% of cells become NBD-positive in 2 h. There was an increase in uptake at higher concentration, indicative of passive diffusion. At the same time, a reduction in uptake at lower temperature (4 °C) compared to that at 37 °C pointed towards some contribution from active transport as well. Variation in uptake after pre-treatment with endocytosis inhibitors such as chlorpromazine and methyl-β-cyclodextrin suggested involvement of clathrin- and caveolae-mediated endocytic pathways. Cell viability and hemolytic assays further indicated that these nanocarriers have good safety profile.

2022

Cancer-associated fibroblast-derived exosomal miR-18b promotes breast cancer invasion and metastasis by regulating TCEAL7

Studies have shown that cancer-associated fibroblasts (CAFs) play an irreplaceable role in the occurrence and development of tumors. Therefore, exploring the action and mechanism of CAFs on tumor cells is particularly important. In this study, we compared the effects of CAFs-derived exosomes and normal fibroblasts (NFs)-derived exosomes on breast cancer cells migration and invasion. The results showed that exosomes from both CAFs and NFs could enter into breast cancer cells and CAFs-derived exosomes had a more enhancing effect on breast cancer cells migration and invasion than NFs-derived exosomes. Furthermore, microRNA (miR)-18b was upregulated in CAFs-derived exosomes, and CAFs-derived exosomes miR-18b can promote breast cancer cell migration and metastasis by specifically binding to the 3'UTR of Transcription Elongation Factor A Like 7 (TCEAL7). The miR-18b-TCEAL7 pathway promotes nuclear Snail ectopic activation by activating nuclear factor-kappa B (NF-κB), thereby inducing epithelial-mesenchymal transition (EMT) and promoting cell invasion and metastasis. Moreover, CAFs-derived exosomes miR-18b could promote mouse xenograft model tumor metastasis. Overall, our findings suggest that CAFs-derived exosomes miR-18b promote nuclear Snail ectopic by targeting TCEAL7 to activate the NF-κB pathway, thereby inducing EMT, invasion, and metastasis of breast cancer. Targeting CAFs-derived exosome miR-18b may be a potential treatment option to overcome breast cancer progression.

2021

Burn Injury-Induced Extracellular Vesicle Production and Characteristics

ABSTRACT: Extracellular vesicles (EVs) are nano-sized membrane-bound particles containing biologically active cargo molecules. The production and molecular composition of EVs reflect the physiological state of parent cells, and once released into the circulation, they exert pleiotropic functions via transferring cargo contents. Thus, circulating EVs not only serve as biomarkers, but also mediators in disease processes or injury responses. In the present study, we performed a comprehensive analysis of plasma EVs from burn patients and healthy subjects, characterizing their size distribution, concentration, temporal changes, cell origins, and cargo protein contents. Our results indicated that burn injury induced a significant increase in circulating EVs, the response peaked at the time of admission and declined over the course of recovery. Importantly, EV production correlated with injury severity, as indicated by the total body surface area and depth of burn, requirement for critical care/ICU stay, hospitalization length, wound infection, and concurrence of sepsis. Burn patients with inhalation injury showed a higher level of EVs than those without inhalation injury. We also evaluated patient demographics (age and sex) and pre-existing conditions (hypertension, obesity, and smoking) and found no significant correlation between these conditions and overall EV production. At the molecular level, flow cytometric analysis showed that the burn-induced EVs were largely derived from leukocytes and endothelial cells (ECs), which are known to be activated postburn. Additionally, a high level of zona-occludens-1 (ZO-1), a major constituent of tight junctions, was identified in burn EV cargos, indicative of injury in tissues that form barriers via tight junctions. Moreover, when applied to endothelial cell monolayers, burn EVs caused significant barrier dysfunction, characterized by decreased transcellular barrier resistance and disrupted cell-cell junction continuity. Taken together, these data suggest that burn injury promotes the production of EVs containing unique cargo proteins in a time-dependent manner; the response correlates with injury severity and worsened clinical outcomes. Functionally, burn EVs serve as a potent mediator capable of reducing endothelial barrier resistance and impairing junction integrity, a pathophysiological process underlying burn-associated tissue dysfunction. Thus, further in-depth characterization of circulating EVs will contribute to the development of new prognostic tools or therapeutic targets for advanced burn care.

2022

Bone Marrow Mesenchymal Stem Cells-Derived Extracellular Vesicles Promote Proliferation, Invasion and Migration of Osteosarcoma Cells via the lncRNA MALAT1/miR-143/NRSN2/Wnt/β-Catenin Axis

Introduction Osteosarcoma is a malignant primary bone tumor. Bone marrow-derived mesenchymal stem cells-derived extracellular vesicles (BMSC-EVs) bear repair function for bone and cartilage. This study investigated the mechanism of BMSC-EVs in osteosarcoma cell proliferation, migration and invasion. Methods BMSC-EVs were isolated and identified. The effects of different concentrations of EVs on osteosarcoma cell proliferation, migration and invasion were evaluated. LncRNA MALAT1 expression in osteosarcoma cells was detected. BMSCs were transfected with si-MALAT1 or si-NC. The binding relationships between MALAT1 and miR-143, and miR-143 and NRSN2 were verified. Levels of NRSN2 and Wnt/β-catenin pathway key proteins were detected. miR-143 mimic was transfected into EVs-treated osteosarcoma cells. Nude mice were injected with MG63 cells to verify the effect of EVs on osteosarcoma growth in vivo. Results BMSC-EVs facilitated proliferation, invasion and migration of osteosarcoma cells. BMSC-EVs carried MALAT1 into osteosarcoma cells. BMSC-EVs-treated osteosarcoma cells showed increased MALAT1 and NRSN2 expressions, decreased miR-143 expression, and activated Wnt/β-catenin pathway. miR-143 mimic or si-MALAT1 reversed the effects of BMSC-EVs on osteosarcoma cells. In vivo experiment confirmed that BMSC-EVs promoted tumor growth in nude mice. Discussion BMSC-EVs promoted proliferation, invasion and migration of osteosarcoma cells via the MALAT1/miR-143/NRSN2/Wnt/β-catenin axis. This study might offer new insights into osteosarcoma management. Keywords: osteosarcoma, bone marrow-derived mesenchymal stem cells, extracellular vesicles, lncRNA MALAT1, miR-143, NRSN2, Wnt/β-catenin pathway

2021

Bone marrow mesenchymal stem cell derived exosomes delay the occurrence and development of osteoarthritis through cartilage protection.

Osteoarthritis is the most common joint degenerative disease. At present, bone marrow mesenchymal stem cells have been used in the treatment of osteoarthritis. However, compared with bone marrow mesenchymal stem cells, bone marrow mesenchymal stem cell derived exosome transplantation has more advantages, such as non-immunogenicity, non-tumorigenicity, convenient storage and transportation. OBJECTIVE: To explore the protective effect of bone marrow mesenchymal stem cell exosomes on osteoarthritis.  METHODS: (1) SD rat bone marrow mesenchymal stem cells were extracted and identified by cell morphology and flow cytometry. Exosomes in the cell supernatant were extracted by ultracentrifugation and identified by transmission electron microscopy, particle size and western blot assay. (2) Primary costal chondrocytes were extracted from suckling rats and cocultured with fluorescently labeled exosomes for 12 hours. The phagocytosis of chondrocytes was observed. In vitro chondrocyte damage was induced by interleukin-1β. PBS (100 μL) containing 50 μg exosomes was added for 24 hours. The expression of matrix metalloproteinase-13 and type II collagen fiber α1 protein was detected by immunofluorescence to evaluate the protective effect of exosomes on injured chondrocytes. (3) The rat model of osteoarthritis was induced by iodoacetic acid in vivo. Exosomes were injected into the joint cavity, and the changes of joint structure of osteoarthritis were observed by hematoxylin-eosin staining and safrane-fast green staining. The expression of matrix metalloproteinase-13 and type II collagen fiber α1 protein was measured by immunohistochemical staining to evaluate the protective effect of exosomes on cartilage in vivo.  RESULTS AND CONCLUSION: (1) The extracted primary cells showed a typical fusiform shape and arranged radially. The extracted cells highly expressed CD73 and CD105, but slightly expressed CD45, CD34 and CD3. Transmission electron microscopy showed that the obtained particles showed a typical saucer-like morphology. The particle size was less than 100 nm. Meanwhile, nanoparticles showed positive expression of ALIX and HRS protein. (2) Typical red-stained particles could be observed in chondrocytes, which confirms that exosomes could be taken up by chondrocytes, and exosomes could promote chondrocyte type II collagen fiber α1 protein expression, but inhibit the expression of matrix metalloproteinase-13, which confirmed that exosomes could attenuate the damage effect of interleukin-1β on chondrocytes. (3) Exosomes could promote the morphological recovery of damaged articular cartilage and the up-regulate type II collagen fiber α1 expression, while inhibited the expression of matrix metalloproteinase-13, which also confirmed that exosomes can alleviate the effects of iodoacetic acid on articular cartilage damage. (4) Above findings results indicate that bone marrow mesenchymal stem cell exosomes delay the occurrence and development of osteoarthritis through a chondroprotective mechanism.

2021

Breast cancer extracellular vesicles-derived miR-1290 activates astrocytes in the brain metastatic microenvironment via the FOXA2→CNTF axis to promote progression of brain metastases

Mechanisms underlying breast cancer brain metastasis (BCBM) are still unclear. In this study, we observed that extracellular vesicles (EVs) secreted from breast cancer cells with increased expression of tGLI1, a BCBM-promoting transcription factor, strongly activated astrocytes. EV-derived microRNA/miRNA microarray revealed tGLI1-positive breast cancer cells highly secreted miR-1290 and miR-1246 encapsulated in EVs. Genetic knockin/knockout studies established a direct link between tGLI1 and both miRNAs. Datamining and analysis of patient samples revealed that BCBM patients had more circulating EV-miRs-1290/1246 than those without metastasis. Ectopic expression of miR-1290 or miR-1246 strongly activated astrocytes whereas their inhibitors abrogated the effect. Conditioned media from miR-1290- or miR-1246-overexpressing astrocytes promoted mammospheres. Furthermore, miRs-1290/1246 suppressed expression of FOXA2 transcription repressor, leading to CNTF cytokine secretion and subsequent activation of astrocytes. Finally, we conducted a mouse study to demonstrate that astrocytes overexpressing miR-1290, but not miR-1246, enhanced intracranial colonization and growth of breast cancer cells. Collectively, our findings demonstrate, for the first time, that breast cancer EV-derived miR-1290 and miR-1246 activate astrocytes in the brain metastatic microenvironment and that EV-derived miR-1290 promotes progression of brain metastases through the novel EV-miR-1290→FOXA2→CNTF signaling axis.

2022

BMSC-EV-derived lncRNA NORAD Facilitates Migration, Invasion, and Angiogenesis in Osteosarcoma Cells by Regulating CREBBP via Delivery of miR-877-3p

Bone marrow mesenchymal stem cells (BMSCs) can boost osteosarcoma (OS) cell proliferation and invasion, yet the function of extracellular vesicles (EVs) derived from BMSCs on OS is scarcely known. This study is aimed at examining the role of BMSC-EVs in OS cells. BMSCs and BMSC-EVs were isolated and identified. The effect of EVs and EVs-si-NORAD on OS cell proliferation, invasion, migration, and angiogenesis was determined. Expressions of NORAD, miR-877-3p, and CREBBP were detected. The binding relationship among NORAD, miR-877-3p, and CREBBP was verified. The miR-877-3p inhibitor or pc-CREBBP was delivered into OS cells treated with EVs-si-NORAD for in vitro analysis. The nude mouse model of the subcutaneous tumor xenograft was established for in vivo analysis. BMSC-EVs promoted OS cell proliferation, invasion, migration, and angiogenesis. BMSC-EVs carried NORAD into OS cells and upregulated CREBBP by sponging miR-877-3p. miR-877-3p downregulation or CREBBP overexpression partly inverted the inhibitory effect of EVs by silencing NORAD on OS cell proliferation, invasion, migration, and angiogenesis. In vivo experiments validated that BMSC-EV-derived NORAD facilitated tumor growth by upregulating CREBBP via miR-877-3p. To conclude, BMSC-EV-derived NORAD facilitated OS cell proliferation, invasion, migration, and angiogenesis by modulating CREBBP via miR-877-3p, which may offer new insights into OS treatment.

2022

Blockade of exosome release alters HER2 trafficking to the plasma membrane and gives a boost to Trastuzumab

Objective(s) Exosomal HER2 has been evidenced to interfere with antibody-induced anti-tumor effects. However, whether the blockade of HER2+ exosomes release would affect antibody-mediated tumor inhibition has yet to be investigated. Methods Exosomes derived from BT-474, SK-BR3 and SK-OV3 (HER2-overexpressing tumor cells) and MDA-MB-231 cells (HER2 negative) were purified and characterized by bicinchoninic acid (BCA) assay, western blotting and Transmission electron microscopy (TEM). Inhibition of exosome release was achieved by neutral sphingomyelinase-2 (nSMase-2) inhibitor, GW4869. The effects of exosome blockade on the anti-proliferative effects, apoptosis induction, and antibody-mediated cellular cytotoxicity (ADCC) activity of Trastuzumab were examined using MTT, flow cytometry, and LDH release assays. Also, the effects of exosome inhibition on the surface expression and endocytosis/internalization of HER2 were studied by flow cytometry. Results Purified exosomes derived from HER2 overexpressing cancer cells were positive for HER2 protein. Blockade of exosome release was able to significantly improve apoptosis induction, anti-proliferative and ADCC responses of Trastuzumab dose dependently. The pretreatment of Trastuzumab/purified NK cells, but not PBMCs, with HER2+ exosomes could also decrease the ADCC effects of Trastuzumab. Exosome inhibition also remarkably downregulated surface HER2 levels in a time-dependent manner, but does not affect its endocytosis/internalization. Conclusion Based on our findings, HER2+ exosomes may benefit tumor progression by dually suppressing Trastuzumab-induced tumor growth inhibition and cytotoxicity of NK cells. It seems that concomitant blocking of exosome release might be an effective approach for improving the therapeutic effects of Trastuzumab, and potentially other HER2-directed mAbs. In addition, the exosome secretion pathway possibly contributes to the HER2 trafficking to plasma membrane, since the blockade of exosome secretion decreased surface HER2 levels.

2022

Biophysical and Computational Studies of Human Disease Related Proteins with a Single-Pass Transmembrane Helix.

Single-pass transmembrane receptors (SPTMRs) are involved in essential processes of biophysical and pathological nature in the human. This membrane protein family includes receptor tyrosine kinases, integrins, and immunoreceptors, which play an important role in metabolism, growth, proliferation, and apoptosis. SPTMR consists of several distinct domains including the extracellular domain (ECD), the transmembrane domain (TMD), and the intracellular domain (ICD) and exists as a monomer, homo- and/or heterodimer. Upon a ligand ligation through ECD, homo- or heterodimerization of SPTMR forms, followed by consequent modification of the ICDs, leading to the initiation of cellular signaling events. This activation requires interactions between TMD helices whose role in receptor activation becomes important. TMD is further highlighted by the discovery of mutations in the TMD or juxtamembrane domain (JMD) that are associated with human diseases. However, the details of cross-membrane signal transduction via SPTMRs have to be elucidated. Due to the high conformational flexibility of SPTMRs with their diverse structural composition, it is hard to characterize SPTMRs structurally. This drives us to work with only TMD helices of SPTMRs and focus on their interactions in the lipid bilayer environment. Our approach is the use of not only experimental data but also computational MD simulations to understand how TMD helices interact and how mutants associated with diseases affect the dimerization of TMD helices.

2021

Biomechanical responses of encysted zoospores of the oomycete Achlya bisexualis to hyperosmotic stress are consistent with an ability to turgor regulate

Zoospores are motile, asexual reproductive propagules that enable oomycete pathogens to locate and infect new host tissue. While motile, they have no cell wall and maintain tonicity with their external media using water expulsion vacuoles. Once they locate host tissue, they encyst and form a cell wall, enabling the generation of turgor pressure that will provide the driving force for germination and invasion of the host. It is not currently known how these spores respond to the osmotic stresses that might arise due to different environments on and around their hosts that have different osmotic strengths. We have made microaspiration (MA) measurements on > 800 encysted zoospores and atomic force microscopy (AFM) measurements on 12 encysted zoospores to determine their mechanical properties and how these change after hyperosmotic stress. Two types of encysted zoospores (Type A and Type B) were produced from the oomycete Achlya bisexualis, that differed in their morphology and response. With a small hyperosmotic stress (using 0.1 and 0.2 M sorbitol to give media osmolality changes of 155.4 and 295.6 mOsmol/kg), Type A zoospores initially became stiffer, with an increase in the Young's modulus (E) over 30 mins from 0.16 MPa to 0.25 and 0.22 MPa respectively. E then returned to its original value after 120 min. With a greater osmotic stress (using 0.3, 0.4 and 0.5 M sorbitol to give media osmolality changes of 438.2, 587.2 and 787.6 mOsmol/kg) the reverse occurred, with an initial decrease in E over 30 - 60 mins to values of 0.1, 0.08 and 0.09 MPa respectively, before recovery to the original value after 120 min. In 0.5 M sorbitol this recovery was only observed with AFM, but not with MA. Type B zoospores, which may be primary/secondary spores about to release secondary/tertiary spores, or else spores that were damaged during encystment, initially stiffened in response to the lower hyperosmotic stresses with a slight increase in E (from 0.077 to 0.1 MPa after 15 min (with both 0.1 and 0.2 M sorbitol) before recovering to the original value after 60 min. These spores showed no change in response to the higher osmotic stresses. The responses of the Type A spores are consistent with rapid changes in cell wall thickness and a turgor regulation mechanism. Turgor regulation is further supported by microscopic observations of the Type A spores showing protoplast retraction from the cell wall followed by deplasmolysis, coupled with measurements of spore volume. As far as we are aware this is the first demonstration of turgor regulation, not just in encysted zoospores, but in oomycetes in general.

2022

Bioinspired artificial exosomes based on lipid nanoparticles carrying let-7b-5p promote angiogenesis in vitro and in vivo.

MicroRNAs (miRNAs) regulate gene expression by post-transcriptional inhibition of target genes. Proangiogenic small extracellular vesicles (sEVs; popularly identified with the name “exosomes”) with a composite cargo of miRNAs are secreted by cultured stem cells and present in human biological fluids. Lipid nanoparticles (LNPs) represent an advanced platform for clinically approved delivery of RNA therapeutics. In this study, we aimed to (1) identify the miRNAs responsible for sEV-induced angiogenesis; (2) develop the prototype of bioinspired “artificial exosomes” (AEs) combining LNPs with a proangiogenic miRNA, and (3) validate the angiogenic potential of the bioinspired AEs. We previously reported that human sEVs from bone marrow (BM)-CD34+ cells and pericardial fluid (PF) are proangiogenic. Here, we have shown that sEVs secreted from saphenous vein pericytes and BM mesenchymal stem cells also promote angiogenesis. Analysis of miRNA datasets available in-house or datamined from GEO identified the let-7 family as common miRNA signature of the proangiogenic sEVs. LNPs with either hsa-let-7b-5p or cyanine 5 (Cy5)-conjugated Caenorhabditis elegans miR-39 (Cy5-cel-miR-39; control miRNA) were prepared using microfluidic micromixing. let-7b-5p-AEs did not cause toxicity and transferred functionally active let-7b-5p to recipient endothelial cells (ECs). let-7b-AEs also improved EC survival under hypoxia and angiogenesis in vitro and in vivo. Bioinspired proangiogenic AEs could be further developed into innovative nanomedicine products targeting ischemic diseases.

2021

Bioengineered 3D tissue model of intestine epithelium with oxygen gradients to sustain human gut microbiome

The human gut microbiome is crucial to host physiology and health. Therefore, stable in vitro coculture of primary human intestinal cells with a microbiome community is essential for understanding intestinal disease progression and revealing novel therapeutic targets. Here, we present a three-dimensional (3D) scaffold system to regenerate an in vitro human intestinal epithelium that recapitulates many functional characteristics of the in vivo small intestine. The epithelium, derived from human intestinal enteroids, contains mature intestinal epithelial cell types and possesses selectively permeable barrier functions. Importantly, by properly positioning the scaffolds cultured under normal atmospheric conditions, two physiologically relevant oxygen gradients, a proximal-to-distal oxygen gradient along the gastrointestinal (GI) tract and a radial oxygen gradient across the epithelium, were distinguished in the tissues when the lumens were faced up and down in cultures, respectively. Furthermore, the presence of the low oxygen gradients supported the coculture of intestinal epithelial cells along with a complex living commensal gut microbiome (including obligate anaerobes) to simulate temporal microbiome dynamics in the native human gut. This unique silk scaffold platform may enable the exploration of microbiota-related mechanisms of disease pathogenesis and host-pathogen dynamics in infectious diseases including the potential to explore the human microbiome-gut-brain axis and potential novel microbiome-based therapeutics.

2022

Bioengineered 3D Skeletal Muscle Model Reveals Complement 4b as a Cell-Autonomous Mechanism of Impaired Regeneration with Aging

A mechanistic understanding of cell-autonomous skeletal muscle changes after injuries can lead to novel interventions to improve functional recovery in an aged population. However, major gaps in our understanding persist owing to limitations of commonly used biological aging models. Two-dimensional cell culture represents an artificial environment, while aging mammalian models are contaminated by influences from non-muscle cells and other organs. We created a three-dimensional muscle aging system to overcome the limitations of these traditional platforms. Here, we first show that old muscle constructs (OMC) manifest a sarcopenic phenotype, as evidenced by hypotrophic myotubes, reduced contractile function, and decreased regenerative capacity compared to young muscle constructs (YMC). OMC also phenocopy the regenerative responses of aged muscle to two interventions, pharmacological and biological. Next, interrogation of muscle cell-specific mechanisms that contribute to impaired regeneration over time reveals that an aging-induced increase of complement component 4b (C4b) delays muscle progenitor cell amplification and impairs functional recovery. However, administration of complement factor I, a C4b inactivator, improves muscle regeneration in vitro and in vivo, indicating C4b inhibition may be a novel approach to enhance aged muscle repair. Collectively, our model exhibits capabilities to study cell-autonomous changes in skeletal muscle during aging, regeneration, and intervention.

2023

Bioanalytics for Influenza Virus-Like Particle Characterization and Process Monitoring

Virus-like particles (VLPs) are excellent platforms for the development of influenza vaccine candidates. Nonetheless, their characterization is challenging due to VLPs' unique biophysical and biochemical properties. To cope with such complexity, multiple analytical techniques have been developed to date (e.g., single-particle analysis, thermal stability, or quantification assays), most of which are rarely used or have been successfully demonstrated for being applicable for virus particle characterization. In this study, several biophysical and biochemical methods have been evaluated for thorough characterization of monovalent and pentavalent influenza VLPs from diverse groups (A and B) and subtypes (H1 and H3) produced in insect cells using the baculovirus expression vector system (IC-BEVS). Particle size distribution and purity profiles were monitored during the purification process using two complementary technologies - nanoparticle tracking analysis (NTA) and tunable resistive pulse sensing (TRPS). VLP surface charge at the selected process pH was also assessed by this last technique. The morphology of the VLP (size, shape, and presence of hemagglutinin spikes) was evaluated using transmission electron microscopy. Circular dichroism was used to assess VLPs' thermal stability. Total protein, DNA, and baculovirus content were also assessed. All VLPs analyzed exhibited similar size ranges (90-115 nm for NTA and 129-141 nm for TRPS), surface charges (average of -20.4 mV), and morphology (pleomorphic particles resembling influenza virus) exhibiting the presence of HA molecules (spikes) uniformly displayed on M1 protein scaffold. Our data shows that HA titers and purification efficiency in terms of impurity removal and thermal stability were observed to be particle dependent. This study shows robustness and generic applicability of the tools and methods evaluated, independent of VLP valency and group/subtype. Thus, they are most valuable to assist process development and enhance product characterization.

2022

Bioanalytics for Influenza Virus-Like Particle Characterization and Process Monitoring

Virus-like particles (VLPs) are excellent platforms for the development of influenza vaccine candidates. Nonetheless, their characterization is challenging due to VLPs’ unique biophysical and biochemical properties. To cope with such complexity, multiple analytical techniques have been developed to date (e.g., single-particle analysis, thermal stability, or quantification assays), most of which are rarely used or have been successfully demonstrated for being applicable for virus particle characterization. In this study, several biophysical and biochemical methods have been evaluated for thorough characterization of monovalent and pentavalent influenza VLPs from diverse groups (A and B) and subtypes (H1 and H3) produced in insect cells using the baculovirus expression vector system (IC-BEVS). Particle size distribution and purity profiles were monitored during the purification process using two complementary technologies — nanoparticle tracking analysis (NTA) and tunable resistive pulse sensing (TRPS). VLP surface charge at the selected process pH was also assessed by this last technique. The morphology of the VLP (size, shape, and presence of hemagglutinin spikes) was evaluated using transmission electron microscopy. Circular dichroism was used to assess VLPs’ thermal stability. Total protein, DNA, and baculovirus content were also assessed. All VLPs analyzed exhibited similar size ranges (90–115 nm for NTA and 129–141 nm for TRPS), surface charges (average of −20.4 mV), and morphology (pleomorphic particles resembling influenza virus) exhibiting the presence of HA molecules (spikes) uniformly displayed on M1 protein scaffold. Our data shows that HA titers and purification efficiency in terms of impurity removal and thermal stability were observed to be particle dependent. This study shows robustness and generic applicability of the tools and methods evaluated, independent of VLP valency and group/subtype. Thus, they are most valuable to assist process development and enhance product characterization.

2022
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Other
Other
Nanomedicine
Nanomedicine
Viruses
Viruses
Extracellular Vesicles
Extracellular Vesicles
DXter
DXter
EV Sample Processing
EV Sample Processing
Zenco
Zenco
Nanopore
Nanopore
Unknown
Unknown
qEV RNA Extraction Kit
qEV RNA Extraction Kit
qEV Magnetic Concentration Kit
qEV Magnetic Concentration Kit
qEV Concentration Kit
qEV Concentration Kit
qEV Legacy Columns
qEV Legacy Columns
qEV Gen 2 Columns
qEV Gen 2 Columns
qNano
qNano
Exoid
Exoid
Automatic Fraction Collector (AFC) V2
Automatic Fraction Collector (AFC) V2
Automatic Fraction Collector (AFC) V1
Automatic Fraction Collector (AFC) V1
Other
Other
qEV
qEV
TRPS
TRPS
Bioprocessing
Bioprocessing
Lipid Nanoparticle
Lipid Nanoparticle
Platelet
Platelet
Vaccine
Vaccine
Liposome
Liposome
MicroRNA
MicroRNA
Zeta Potential
Zeta Potential