The effect of squalane-dissolved fullerene-C60 on adipogenesis-accompanied oxidative stress and macrophage activation in a preadipocyte-monocyte co-culture system

Interplay of co-cultured chimeric adipose and gingival tissues exacerbates inflammatory dysfunction relevant to periodontal and metabolic conditions

Adipose tissue dysfunction is a key feature of metabolic syndrome, which increases the risk of periodontitis, an inflammatory disease induced by bacteria that affects the gingiva and other components of periodontal tissue. Recent studies indicate that molecules from inflamed periodontal tissue contribute to adipose tissue dysfunction. However, the cellular mechanisms and interactions between adipose tissue and gingiva driving the progression of metabolic and periodontal conditions remain unclear. To address this, we developed a chimeric (mouse/human) co-culture tissue model (which identifies the origins of species-specific cytokines) to investigate these interactions. Using tissue-specific functional cells and immunocytes, we constructed equivalents of adipose tissue (ATE) and gingiva (GTE), co-cultivating them under inflammatory conditions induced by bacterial endotoxin, lipopolysaccharide (LPS). Our findings showed that exposure to LPS resulted in a notable reduction in lipid accumulation, GLUT4 expression, and adiponectin secretion in ATE, along with increased macrophage colonies forming around lipid droplets, as well as elevated levels of triglyceride, leptin, and IL-6. In GTE, LPS triggered significant inflammatory responses, characterized by increased macrophage accumulation, elevated COX-2 expression, and heightened secretion of inflammatory cytokines. LPS also reduced epithelial thickness and the expression of keratin 19 and collagen IV, indicating impaired barrier function and gingival integrity. Co-culturing ATE with GTE exacerbated these LPS-induced harmful effects in both tissues. In conclusion, our findings suggest that interplay between gingiva and adipose tissue can intensify the inflammatory and dysfunctional changes caused by LPS. This co-culture tissue model offers a valuable tool for future studies on periodontitis and metabolic syndrome.

Pathological roles of bone marrow adipocyte-derived monocyte chemotactic protein-1 in type 2 diabetic mice

Type 2 diabetes mellitus (T2DM) has become a prevalent public health concern, with beta-cell dysfunction involved in its pathogenesis. Bone marrow adipose tissue (BMAT) increases in both the quantity and area in individuals with T2DM along with heightened monocyte chemotactic protein-1 (MCP-1) secretion. This study aims to investigate the influence and underlying mechanisms of MCP-1 originating from bone marrow adipocytes (BMAs) on systemic glucose homeostasis in T2DM. Initially, a substantial decrease in the proliferation and glucose-stimulated insulin secretion (GSIS) of islet cells was observed. Moreover, a comparative analysis between the control (Ctrl) group and db/db mice revealed significant alterations in the gene expression profiles of whole bone marrow cells, with a noteworthy upregulation of Mcp-1. And the primary enriched pathways included chemokine signaling pathway and AGE-RAGE signaling pathway in diabetic complications. In addition, the level of MCP-1 was distinctly elevated in BMA-derived conditional media (CM), leading to a substantial inhibition of proliferation, GSIS and the protein level of phosphorylated Akt (p-Akt) in Min6 cells. After blocking MCP-1 pathway, we observed a restoration of p-Akt and the proliferation of islet cells, resulting in a marked improvement in disordered glucose homeostasis. In summary, there is an accumulation of BMAs in T2DM, which secrete excessive MCP-1, exacerbating the abnormal accumulation of BMAs in the bone marrow cavity through paracrine signaling. The upregulated MCP-1, in turn, worsens glucose metabolism disorder by inhibiting the proliferation and insulin secretion of islet cells through an endocrine pathway. Inhibiting MCP-1 signaling can partially restore the proliferation and insulin secretion of islet cells, ultimately ameliorating glucose metabolism disorder. It's worth noting that to delve deeper into the impact of MCP-1 derived from BMAs on islet cells and its potential mechanisms, it is imperative to develop genetically engineered mice with conditional Mcp-1 knockout from BMAs.

Efficiently normalizing leukopoiesis by gadofullerene nanoparticles to ameliorate radiation-triggered myelosuppression

Myelosuppression is a predominant side-effect of radiotherapy, which manifests as the lower activity of blood cell precursors in bone marrow. Though progress in anti-myelosuppression has been made by the application of growth factors e.g., the granulocyte colony-stimulating factor (G-CSF), the side-effects (e.g., bone-pain, liver injury, and lung toxicity) limit their applications in clinic. Herein, we developed a strategy of efficiently normalizing leukopoiesis using gadofullerene nanoparticles (GFNPs) against myelosuppression triggered by radiation. Specifically, GFNPs with high radical-scavenging abilities elevated the generation of leukocytes and alleviated the bone marrow's pathological state under myelosuppression. Notably, GFNPs potentiated the differentiation, development, and maturation of leukocytes (neutrophils, lymphocytes) in radiation bearing mice even better than what G-CSF did. In addition, GFNPs had little toxicity towards the main organs including the heart, liver, spleen, lung, and kidney. This work provides an in-depth understanding of how advanced nanomaterials mitigate myelosuppression by regulating leukopoiesis.

Types of cell culture inserts affect cell crosstalk between co-cultured macrophages and adipocytes

Cell culture inserts offer an in vivo-like microenvironment to investigate cell-cell interactions between co-cultivated cells. However, it is unclear if types of inserts affect cell crosstalk. Here, we developed an environment-friendly cell culture insert, XL-insert, which can reduce plastic waste with lower cost. We compared XL insert with two types of commercial disposable culture inserts, Koken® insert with atelocollagen membrane (Col-inserts) and Falcon® inserts with plastic membrane (PET-inserts) on cell-cell interactions in co-cultivated THP-1 macrophages and OP9 adipocytes. Scanning electron microscope, immunoassay and imaging analysis showed that among three types of inserts, XL-inserts allowed cytokines from co-cultivated macrophages and adipocytes to diffuse freely and offered preferable in vivo-like microenvironment for cell-cell interactions. PET-inserts showed limitations for intercellular communication due to some pores being blocked by somas on the membrane that caused much lower permeability for cytokines passing through. Col-inserts blocked large sized cytokines but allowed small sized molecules to permeate resulting in improved lipid accumulation and adiponectin secretion in OP9 adipocytes. Taken together, our data demonstrated that membrane type and pore size on the membrane affect the cross-talk between co-cultivated cells very differently. Some previous co-culture studies might have different results if the inserts were changed.

Liposomes Containing Amaranth Unsaponifiable Matter and Soybean Lunasin Suppress ROS Production in Fibroblasts and Reduced Interleukin Production in Macrophages

Inflammation is a normal response in defense to agents that may cause damage to the human body. When inflammation becomes chronic, reactive oxygen species (ROS) are produced; which could lead to diseases such as cancer. The aim was to assess liposomes' antioxidant and anti-inflammatory capacity loaded with amaranth unsaponifiable matter and soybean lunasin (UM + LunLip) in an in vitro model using fibroblasts and macrophages. To evaluate ROS production, fibroblasts CHON-002 ABAP were added to promote ROS production; and the cells were treated with UM + LunLip. For inflammation markers production, lipopolysaccharides (LPS)-stimulated RAW 264.7 and peritoneal macrophages were treated with empty liposomes (EmLip), liposomes loaded with unsaponifiable matter (UMLip), liposomes loaded with lunasin (LunLip), and UM + LunLip. ROS production was significantly decreased by 77% (p < 0.05) when fibroblasts were treated with UM + LunLip at 2 mg lunasin/mL compared with the control treated with ABAP. Treatment with UMLip was the most effective in reducing tumor necrosis factor-α (71-90%) and interleukin-6 (43-55%, p < 0.001). Both liposomes containing unsaponifiable matter (UMLip and UM + LunLip) were more effective than EmLip or LunLip. In conclusion, amaranth unsaponifiable matter-loaded liposomes are effective in decreasing pro-inflammatory cytokine production.

Enzyme-digested Colla Corii Asini (E'jiao) suppresses lipopolysaccharide-induced inflammatory changes in THP-1 macrophages and OP9 adipocytes

Gut microbial lipopolysaccharides (LPS)-induced inflammatory responses in adipose tissue are associated with the dysfunction of adipocytes, insulin resistance and the development of metabolic syndrome. The aim of this study is to investigate (1) the effects of LPS on the differentiation and inflammatory responses of THP-1 monocytes and OP9 preadipocytes under serum free conditions and (2) the repressive effects of enzyme-digested Colla Corii Asini (CCAD) and fish gelatin (FGD) on LPS-induced inflammatory responses in THP-1 macrophages and OP9 adipocytes. Immunofluorescence and oil red O staining showed that a serum free medium supplied with phorbol 12-myristate 13-acetate (PMA) could induce differentiation and lipid accumulation in THP-1 cells as well as OP9 cells. ELISA showed that LPS significantly increased interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) secretions in PMA-differentiated THP-1 macrophages in a dose-dependent manner. LPS significantly suppressed lipid accumulation and adiponectin secretions, and enhanced IL-6 secretions in OP9 adipocytes. Both CCAD and FGD significantly reduced the levels of both macrophages- and adipocytes-derived inflammatory cytokines and increased the level of OP9-secreted adiponectin. In conclusion, LPS could induce inflammatory responses in both THP-1 and OP9 cells and cause dysfunction of OP9 adipocytes under the serum free conditions. CCAD and FGD can repress LPS-induced inflammatory responses in both THP-1 macrophages and OP9 adipocytes, and increase the secretion of adiponectin in OP9 adipocytes. They could be used as health care supplements for improving metabolic syndrome.

Hydrogen-Rich Water Prevents Dehydration-Induced Cellular Oxidative Stress and Cell Death in Human Skin Keratinocytes

Hypohydration is linked to increased risk of a variety of diseases and can be life-threatening, especially in elderly populations. Dehydration induces cellular damage partially through the production of reactive oxygen species (ROS) in cells, tissues and organs. Hydrogen molecules are known to convert ROS to harmless water. Therefore, theoretically hydrogen-rich water (HW) might eliminate dehydration-induced ROS and reverse its harmful effects in cells. In this in vitro study, we demonstrated that air-drying for 5 min could induce ROS generation in both nucleus and cytoplasm of human keratinocytes HaCaT as quantified by CellROX® Green/Orange reagents (Thermo Fisher Scientific, Waltham, Massachusetts, U.S.), respectively. Conversely, when the air-drying time was increased to 10 and 20 min, HaCaT cells lost the ability to produce ROS. Scanning electron microscopic (SEM) images showed that 10 min air-drying could induce severe membrane damage in HaCaT cells. PrestoBlue assay showed that, when HaCaT cells were air-dried for 20 min, cell viability was decreased to 27.6% of the control cells 48 h later. However, once HaCaT cells were pretreated with HW-prepared media, dehydration-induced intracellular ROS, cell membrane damage and cell death were significantly reduced as compared with double distilled water (DDW) under the same conditions. In conclusion, our data suggested that HW can decrease dehydration-induced harmful effects in human cells partially through its antioxidant capacity.

Advances in research on fat infiltration and lumbar intervertebral disc degeneration

Low back pain (LBP) is a disabling condition with no available cure, severely affecting patients' quality of life. Intervertebral disc degeneration (IVDD) is the leading cause of chronic low back pain (CLBP). IVDD is a common and recurrent condition in spine surgery. Disc degeneration is closely associated with intervertebral disc inflammation. The intervertebral disc is an avascular tissue in the human body. Transitioning from hematopoietic bone marrow to bone marrow fat may initiate an inflammatory response as we age, resulting in bone marrow lesions in vertebrae. In addition, the development of LBP is closely associated with spinal stability imbalance. An excellent functional state of paraspinal muscles (PSMs) plays a vital role in maintaining spinal stability. Studies have shown that the diminished function of PSMs is mainly associated with increased fat content, but whether the fat content of PSMs is related to the degree of disc degeneration is still under study. Given the vital role of PSMs lesions in CLBP, it is crucial to elucidate the interaction between PSMs changes and CLBP. Therefore, this article reviews the advances in the relationship and the underlying mechanisms between IVDD and PSMs fatty infiltration in patients with CLBP.

Hydrogen Nano-Bubble Water Suppresses ROS Generation, Adipogenesis, and Interleukin-6 Secretion in Hydrogen-Peroxide- or PMA-Stimulated Adipocytes and Three-Dimensional Subcutaneous Adipose Equivalents

Reactive oxygen species (ROS)-induced oxidative stress in adipose tissue is associated with inflammation and the development of obesity-related metabolic disorders. The aim of this study is to investigate the effects of hydrogen nano-bubble water (HW) on ROS generation, adipogenesis, and interleukin-6 (IL-6) secretion in hydrogen peroxide (H₂O₂) or phorbol 12-myristate 13-acetate (PMA)-stimulated OP9 adipocytes, and three-dimensional (3D) subcutaneous adipose equivalents. Nanoparticle tracking analysis showed that fresh HW contains 1.17 × 10⁸/mL of nano-sized hydrogen bubbles. Even after 8 to 13 months of storage, approximately half of the bubbles still remained in the water. CellROX^® staining showed that HW could diminish H₂O₂- or PMA-induced intracellular ROS generation in human keratinocytes HaCaT and OP9 cells. We discovered that PMA could markedly increase lipid accumulation to 180% and IL-6 secretion 2.7-fold in OP9 adipocytes. Similarly, H₂O₂ (5 µM) also significantly stimulated lipid accumulation in OP9 cells and the 3D adipose equivalents. HW treatment significantly repressed H₂O₂- or PMA-induced lipid accumulation and IL-6 secretion in OP9 adipocytes and the 3D adipose equivalents. In conclusion, HW showed a possibility of repressing oxidative stress, inflammatory response, and adipogenesis at cellular/tissue levels. It can be used for preventing the development of metabolic disorders amongst obese people.

Squalene Stimulates a Key Innate Immune Cell to Foster Wound Healing and Tissue Repair

Anti-inflammatory effects of virgin olive oil (VOO) have been described recently, along with its wound healing effect. One of the main minor compounds found in VOO is squalene (SQ), which also possesses preventive effects against skin damage and anti-inflammatory properties. The inflammatory response is involved in wound healing and manages the whole process by macrophages, among others, as the main innate cells with a critical role in the promotion and resolution of inflammation for tissue repair. Because of that, this work is claimed to describe the role that squalene exerts in the immunomodulation of M1 proinflammatory macrophages, which are the first cells implicate in recent injuries. Pro- and anti-inflammatory cytokines were analysed using TPH1 cell experimental model. SQ induced an increase in the synthesis of anti-inflammatory cytokines, such as IL-10, IL-13, and IL-4, and a decrease in proinflammatory signals, such as TNF-α and NF-κB in M1 proinflammatory macrophages. Furthermore, SQ enhanced remodelling and repairing signals (TIMP-2) and recruitment signals of eosinophils and neutrophils, responsible for phagocytosis processes. These results suggest that SQ is able to promote wound healing by driving macrophage response in inflammation. Therefore, squalene could be useful at the resolution stage of wound healing.

Multifunctional Carbon-Based Nanomaterials: Applications in Biomolecular Imaging and Therapy

Molecular imaging has been widely used not only as an important detection technology in the field of medical imaging for cancer diagnosis but also as a theranostic approach for cancer in recent years. Multifunctional carbon-based nanomaterials (MCBNs), characterized by unparalleled optical, electronic, and thermal properties, have attracted increasing interest and demonstrably hold the greatest promise in biomolecular imaging and therapy. As such, it should come as no surprise that MCBNs have already revealed a great deal of potential applications in biomedical areas, such as bioimaging, drug delivery, and tumor therapy. Carbon nanomaterials can be categorized as graphene, single-walled carbon nanotubes, mesoporous carbon, nanodiamonds, fullerenes, or carbon dots on the basis of their morphologies. In this article, reports of the use of MCBNs in various chemical conjugation/functionalization strategies, focusing on their applications in cancer molecular imaging and imaging-guided therapy, will be comprehensively summarized. MCBNs show the possibility to serve as optimal candidates for precise cancer biotheranostics.

Three-dimensional Inflammatory Human Tissue Equivalents of Gingiva

Periodontal diseases (such as gingivitis and periodontitis) are the leading causes of tooth loss in adults. Inflammation in gingiva is the fundamental physiopathology of periodontal diseases. Current experimental models of periodontal diseases have been established in various types of animals. However, the physiopathology of animal models is different from that of humans, making it difficult to analyze cellular and molecular mechanisms and evaluate new medicines for periodontal diseases. Here, we present a detailed protocol for reconstructing human inflammatory tissue equivalents of gingiva (iGTE) in vitro. We first build human tissue equivalents of gingiva (GTE) by utilizing two types of human cells, including human gingival fibroblasts (HGF) and human skin epidermal keratinocytes (HaCaT), under three-dimensional conditions. We create a wound model by using a tissue puncher to punch a hole in the GTE. Next, human THP-1 monocytes mixed with collagen gel are injected into the hole in the GTE. By adimistration of 10 ng/mL phorbol 12-myristate 13-acetate (PMA) for 72 h, THP-1 cells differentiated into macrophages to form inflammatory foci in GTE (iGTE) (IGTE also can be stumilated with 2 µg/mL of lipopolysaccharides (LPS) for 48 h to initiate inflammation). IGTE is the first in vitro model of inflammatory gingiva using human cells with a three-dimensional architecture. IGTE reflects major pathological changes (immunocytes activition, intracellular interactions among fibryoblasts, epithelial cells, monocytes and macrophages) in periodontal diseases. GTE, wounded GTE, and iGTE can be used as versatile tools to study wound healing, tissue regeneration, inflammation, cell-cell interaction, and screen potential medicines for periodontal diseases.

Water-Soluble Fullerene Derivatives as Brain Medicine: Surface Chemistry Determines If They Are Neuroprotective and Antitumor

Delivering drugs to the central nervous system (CNS) is a major challenge in treating CNS-related diseases. Nanoparticles that can cross blood-brain barrier (BBB) are potential tools. In this study, water-soluble C₆₀ fullerene derivatives with different types of linkages between the fullerene cage and the solubilizing addend were synthesized (compounds 1-3: C-C bonds, compounds 4-5: C-S bonds, compound 6: C-P bonds, and compounds 7-9: C-N bonds). Fullerene derivatives 1-6 were observed to induce neural stem cell (NSC) proliferation in vitro and rescue the function of injured CNS in zebrafish. Fullerene derivatives 7-9 were found to inhibit glioblastoma cell proliferation in vitro and reduce glioblastoma formation in zebrafish. These effects were correlated with the cell metabolic changes. Particularly, compound 3 bearing residues of phenylbutiryc acids significantly promoted NSC proliferation and neural repair without causing tumor growth. Meanwhile, compound 7 with phenylalanine appendages significantly inhibited glioblastoma growth without retarding the neural repair. We conclude that the surface functional group determines the properties as well as the interactions of C₆₀ with NSCs and glioma cells, producing either a neuroprotective or antitumor effect for possible treatment of CNS-related diseases.

A tumor-specific cleavable nanosystem of PEG-modified C60@Au hybrid aggregates for radio frequency-controlled release, hyperthermia, photodynamic therapy and X-ray imaging

Taking advantages of fullerene (C60) and gold nanoparticles (AuNPs) for potentials in photodynamic therapy (PDT), drug delivery and radio frequency thermal therapy (RTT), a C60@Au hybrid nanocomposite was synthesized by chemical deposition of Au nanoparticles onto C60, and functionalized by PEG5000 via a pH cleavable hydrazone bond, making C60@Au-PEG keep the PEG on the surface of drug delivery system during circulation but dissociate PEG from the system after accumulation in tumor tissue, then doxorubicin (DOX) was loaded onto C60@Au-PEG with a very high drug loading efficiency. The release profiles of DOX from C60@Au-PEG/DOX showed strong dependences on radio frequency (RF). For the drug delivery, C60@Au-PEG/DOX afforded much higher antitumor efficacy owing to 8.6-fold higher DOX uptake of tumor than DOX. Besides, in this work, C60@Au-PEG/DOX not only served as a powerful RTT agent for RF-thermal ablation of tumor and a strong photosensitizer (PS) for PDT, but also as an X-ray contrast agent for tumor diagnosis. In the in vitro and in vivo studies, C60@Au-PEG/DOX showed excellent chemo-RF thermal-photodynamic therapeutic efficacy, RF-controlled drug releasing function, tumor targeting property, tumoral acid PEG dissociating character and X-ray imaging ability, demonstrating that there is a great potential of C60@Au-PEG/DOX for simultaneous diagnosis and therapy in cancer treatment.

STATEMENT OF SIGNIFICANCE

A significant challenge in cancer therapy is to maximize the therapeutic efficacy and minimize the side effects. In the past decade, a lot of nanoparticles have been used as the carriers for efficient drug delivery. However, the design of drug delivery system (DDS) with stimuli-responsive controlled-release property, simultaneous diagnosis and therapy functions is still a challenge. Herein, we developed a new drug delivery system (C60@Au-PEG/DOX), and explored its applications in tumor therapy. The in vitro and in vivo results showed C60@Au-PEG/DOX could significantly improve the therapeutic efficacy and reduce the systemic toxicity through X-ray imaging guided locatable DOX release, photodynamic and photothermal therapies. These results are of interest as they demonstrate a multi-functional DDS for tumor theranostic applications.

Macrophage apoptosis induced by aqueous C60 aggregates changing the mitochondrial membrane potential

Fullerenes have been applied to various fields in recent years for their unique physicochemical properties. C60's potential environmental and health risks are therefore being investigated. This work presents the cytotoxicity of aqueous C60 aggregates (nC60) by using the mouse peritoneal macrophage (RAW264.7) as a model biological system. Cells incubated with nC60 showed a decrease in cell viability, and the quantities of cell apoptosis increased significantly in a dose-dependent and time-dependent manner. By TEM imaging cells were observed to be asymmetric and shrunken compared to control cells. nC60 was adsorbed onto the plasma membrane and apparent phagocytosis was observed after a 24h exposure. The intracellular reactive oxygen species (ROS) were quantified with the dichlorofluorescein diacetate (DCFH-DA) detection assay kit by flow cytometry and found to increase in treated cells. Membrane damage and lipid peroxidation were not observed, since both intracellular and extracellular MDA showed no variation. Detection of the mitochondrial membrane potential (MMP) by JC-1 assay kit showed that MMP had an obvious dose-dependent loss. We speculate that the nC60 aggregates induced apoptosis of macrophage by changing the mitochondrial membrane potential.

PVP formulated fullerene (C60) increases Rho-kinase dependent vascular tissue contractility in pregnant Sprague Dawley rats

Pregnancy is a unique physiological state, in which C60 fullerene is reported to be distributed in both maternal and fetal tissues. Tissue distribution of C60 differs between pregnant and non-pregnant states, presumably due to functional changes in vasculature during pregnancy. We hypothesized that polyvinylpyrrolidone (PVP) formulated C60 (C60/PVP) increases vascular tissue contractility during pregnancy by increasing Rho-kinase activity. C60/PVP was administered intravenously to pregnant and non-pregnant female Sprague Dawley rats. Vascular responses were assessed using wire myography 24h post-exposure. Increased stress generation was observed in uterine artery, thoracic aorta and umbilical vein. Rho-Rho-kinase mediated force maintenance was increased in arterial segments from C60/PVP exposed pregnant rats when compared to PVP exposed rats. Our findings suggest that intravenous exposure to C60/PVP during pregnancy increases vascular tissue contractility of the uterine artery through elements of Rho-Rho-kinase signaling during late stages of pregnancy.

A tumoral acidic pH-responsive drug delivery system based on a novel photosensitizer (fullerene) for in vitro and in vivo chemo-photodynamic therapy

Fullerene has shown great potential both in drug delivery and photodynamic therapy. Herein, we developed a doxorubicin (DOX)-loaded poly(ethyleneimine) (PEI) derivatized fullerene (C60-PEI-DOX) to facilitate combined chemotherapy and photodynamic therapy in one system, and DOX was covalently conjugated onto C60-PEI by the pH-sensitive hydrazone linkage. The release profiles of DOX from C60-PEI-DOX showed a strong dependence on the environmental pH value. The biodistributions of C60-PEI-DOX were investigated by injecting CdSe/ZnS (Qds) labeled conjugates (C60-PEI-DOX/Qds) into tumor-bearing mice. C60-PEI-DOX/Qds showed a higher tumor targeting efficiency compared with Qds alone. Compared with free DOX in an in vivo murine tumor model, C60-PEI-DOX afforded higher antitumor efficacy without obvious toxic effects to normal organs owing to its good tumor targeting efficacy and the 2.4-fold greater amount of DOX released in the tumor than in the normal tissues. C60-PEI-DOX also showed high antitumor efficacy during photodynamic therapy. The ability of C60-PEI-DOX nanoparticles to combine local specific chemotherapy with external photodynamic therapy significantly improved the therapeutic efficacy of the cancer treatment, the combined treatment demonstrating a synergistic effect. These results suggest that C60-PEI-DOX may be promising for high treatment efficacy with minimal side effects in future therapy.

Fullerol nanoparticles suppress inflammatory response and adipogenesis of vertebral bone marrow stromal cells--a potential novel treatment for intervertebral disc degeneration

BACKGROUND CONTEXT

Intervertebral disc degeneration, leading to chronic back pain, is a major health problem in western societies. Vertebral bone marrow has been considered to play an important role in nutrition supply and metabolic exchange for discs. Vertebral bone marrow lesions, including fatty marrow replacement and inflammatory edema, noted on magnetic resonance imaging were first described in 1988.

PURPOSE

To investigate the potential of a free radical scavenger, fullerol nanoparticles, to prevent vertebral bone marrow lesion and prevent disc degeneration by inhibiting inflammation and adipogenic differentiation of vertebral bone marrow stromal cells (vBMSCs).

STUDY DESIGN/SETTING

Fullerol nanoparticle solutions were prepared to test their in vitro suppression effects on mouse vBMSC inflammation and adipogenic differentiation compared with non-fullerol-treated groups.

METHODS

With or without fullerol treatment, vBMSCs from Swiss Webster mice were incubated with 10 ng/mL interleukin-1 β (IL-1 β). The intracellular reactive oxygen species (ROS) were measured with fluorescence staining and flow cytometry. In addition, vBMSCs were cultured with adipogenic medium (AM) with or without fullerol. Gene and protein expressions were evaluated by real-time polymerase chain reaction and histologic methods.

RESULTS

Fluorescence staining and flow cytometry results showed that IL-1 β markedly increased intracellular ROS level, which could be prevented by fullerol administration. Fullerol also decreased the basal ROS level to 77%. Cellular production of matrix metalloproteinase (MMP)-1, 3, and 13 and tumor necrosis factor alpha (TNF-α) induced by IL-1 β was suppressed by fullerol treatment. Furthermore, adipogenic differentiation of the vBMSCs was retarded markedly by fullerol as revealed by less lipid droplets in the fullerol treatment group compared with the adipogenic group. The expression of adipogenic genes PPARγ and aP2 was highly elevated with AM but decreased on fullerol administration.

CONCLUSIONS

These results suggest that fullerol prevents the catabolic activity of vBMSCs under inflammatory stimulus by decreasing the level of ROS, MMPs, and TNF-α. Also, fat formation in vBMSCs is prevented by fullerol nanoparticles, and, therefore, fullerol may warrant further in vivo investigation as an effective biological therapy for disc degeneration.

Novel treatment of neuroinflammation against low back pain by soluble fullerol nanoparticles

STUDY DESIGN

An in vitro study to investigate the anti-inflammatory effects of fullerol on mouse dorsal root ganglia (DRG) under tumor necrosis factor (TNF)-α induction.

OBJECTIVE

To evaluate the potential of a free radical scavenger, fullerol nanoparticles, to prevent DRG tissue and neuron inflammatory responses under TNF-α induction in vitro.

SUMMARY OF BACKGROUND DATA

Low back pain is one of the most common reasons for clinician visits in Western societies. Symptomatic intervertebral disc degeneration is strongly implicated as a cause of low back pain, as it results in DRG inflammation. Increased production of reactive oxygen species (ROS) is associated with DRG inflammation.

METHODS

With or without fullerol treatment, DRG tissue and DRG neurons isolated from wild-type C3H/HeNCrl (Charles River Laboratories, Wilmington, MA) mice were cultured under TNF-α induction. The amount of intracellular ROS was measured with H2DCFDA (Life Technologies Corporation, Grand Island, NY) fluorescence staining. Cellular apoptosis was detected via terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The expression of inflammatory as well as antioxidative enzyme genes in neurons was analyzed by real-time polymerase chain reaction. In addition, inflammatory cytokine expression in DRG tissue was determined by immunofluorescence staining and enzyme-linked immunosorbent assay.

RESULTS

Fluorescence staining results indicated that TNF-α markedly increased the production of intracellular ROS and the number of apoptotic cells. Under fullerol treatment, cellular apoptosis was reduced along with concomitant suppression of ROS. The expression of inflammatory cytokines interleukin 1 β, interleukin 6, cyclooxygenase-2, and prostaglandin E2, was also inhibited by fullerol in a dose-dependent manner. Furthermore, fullerol-treated cells exhibited upregulation of antioxidative enzyme genes superoxide dismutase 2 and catalase.

CONCLUSION

The results obtained from this study clearly suggest that fullerol treatment suppresses the inflammatory responses of DRG and neurons, as well as cellular apoptosis by decreasing the level of ROS and potentially enhancing antioxidative enzyme gene expression. Therefore, fullerol has potential to serve as a novel therapeutic agent for low back pain treatment.

LEVEL OF EVIDENCE

N/A.

Repressive effects of a capacitive-resistive electric transfer (CRet) hyperthermic apparatus combined with provitamin C on intracellular lipid-droplets formation in adipocytes

PURPOSE

The aim of this study was to evaluate inhibitory effects of L-ascorbic acid-2-O-phosphate-Na(2) (APS), a pro-vitamin C, combined with hyperthermia on adipogenic differentiation of mouse stromal cells, OP9.

MATERIALS AND METHODS

OP9 preadipocytes were differentiated with serum replacement, administered with APS, and simultaneously treated with hyperthermia using a capacitive-resistive electric transfer (CRet) apparatus, which was conducted repeatedly twice a day. After 2 days, intracellular lipid droplets were stained with Oil Red O, then observed by microscopy and assessed spectrophotometrically.

RESULTS

After stimulation by serum replacement for 2 days, lipid droplets were accumulated surrounding nucleus of OP9 cells. When APS of 0.15-0.6 mM was administered without hyperthermia, the amount of lipid droplets was markedly suppressed to 50.5%∼-11.3% versus the undifferentiated control, and diminished huge aggregates of lipid droplets. In OP9 cells treated by hyperthermia at 42°C for 0.5 min, 1 min or 3 min in the absence of APS, adipogenesis was suppressed abruptly in a time-dependent manner to 95.4%, 18.7% or -5.5%, respectively. Whereas, the percentage of adipogenesis was 96.8% in OP9 cells treated by mild hyperthermia alone at 41°C for 1 min. The simultaneous application of APS and hyperthermia at 41°C for 1 min markedly suppressed the accumulation of lipid droplets to 25.7%∼-66.2%. By scanning electron microscopy (SEM) observation, the surface of OP9 cells treated with APS and hyperthermia appeared to have the morphological property of undifferentiated OP9 cells.

CONCLUSION

Combined treatment of APS and mild hyperthermia suppresses adipogenesis in OP9 cells, particularly in lipid droplets accumulation during spontaneous differentiation of OP9 preadipocytes.

Assessing nanoparticle toxicity

Nanoparticle toxicology, an emergent field, works toward establishing the hazard of nanoparticles, and therefore their potential risk, in light of the increased use and likelihood of exposure. Analytical chemists can provide an essential tool kit for the advancement of this field by exploiting expertise in sample complexity and preparation as well as method and technology development. Herein, we discuss experimental considerations for performing in vitro nanoparticle toxicity studies, with a focus on nanoparticle characterization, relevant model cell systems, and toxicity assay choices. Additionally, we present three case studies (of silver, titanium dioxide, and carbon nanotube toxicity) to highlight the important toxicological considerations of these commonly used nanoparticles.

Neuronal uptake and intracellular superoxide scavenging of a fullerene (C60)-poly(2-oxazoline)s nanoformulation

Fullerene, the third allotrope of carbon, has been referred to as a "radical sponge" because of its powerful radical scavenging activities. However, the hydrophobicity and toxicity associated with fullerene limits its application as a therapeutic antioxidant. In the present study, we sought to overcome these limitations by generating water-soluble nanoformulations of fullerene (C(60)). Fullerene (C(60)) was formulated with poly(N-vinyl pyrrolidine) (PVP) or poly(2-alkyl-2-oxazoline)s (POx) homopolymer and random copolymer to form nano-complexes. These C(60)-polymer complexes were characterized by UV-vis spectroscopy, infrared spectroscopy (IR), dynamic light scattering (DLS), atomic force microscopy (AFM) and transmission electron microscopy (TEM). Cellular uptake and intracellular distribution of the selected formulations in catecholaminergic (CATH.a) neurons were examined by UV-vis spectroscopy, immunofluorescence and immunogold labeling. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the ability of these C(60)-polymer complexes to scavenge superoxide. Their cytotoxicity was evaluated in three different cell lines. C(60)-POx and C(60)-PVP complexes exhibited similar physicochemical properties and antioxidant activities. C(60)-poly(2-ethyl-2-oxazoline) (PEtOx) complex, but not C(60)-PVP complex, were efficiently taken up by CATH.a neurons and attenuated the increase in intra-neuronal superoxide induced by angiotensin II (Ang II) stimulation. These results show that C(60)-POx complexes are non-toxic, neuronal cell permeable, superoxide scavenging antioxidants that might be promising candidates for the treatment of brain-related diseases associated with increased levels of superoxide.

Fullerene-polyvinylpyrrolidone clathrate localizes in the cytoplasm to prevent Ultraviolet-A ray-induced DNA-fragmentation and activation of the transcriptional factor NF-kappaB

By Western blot and immunostaining we proved that polyvinylpyrrolidone (PVP)-wrapped fullerene molecules (PVP-fullerene) could combine the 8- and 53-kb proteins which localize in the membrane of human skin keratinocytes HaCaT. Only fullerene molecules are able to cross the lipid membrane and conjugate 53-kb proteins in the cytosol. There are no fullerene molecules detectable in the nucleus or cytoskeleton. Ultraviolet-A (UVA)-irradiation on HaCaT or normal human epidermal melanocytes (NHEM) caused nuclear fragmentations, lowering of intracellular DNA-contents below diploidy, concurrently with the repressed DNA synthesis and the increased DNA-3'OH cleavage terminals, all of which were repressed by PVP-fullerene, as shown by flow cytometry and PI- or TUNEL-stain fluorography. Translocation of the transcriptional factor NF-kappaB in the cytoplasm to the nucleus of the keratinocytes was caused with UVA and repressed by PVP-fullerene with cytoprotective effects. Thus, the PVP-fullerene may be developed as a UV-protective agent with DNA-preservative effects owing to its combinative ability to molecules in the cytoplasm and cytomembrane, and then represses cellular oxidative stress and blocks abnormal signal pathways.

THP-1 Macrophages and SGBS Adipocytes - A New Human in vitro Model System of Inflamed Adipose Tissue

Obesity is associated with an accumulation of macrophages in adipose tissue. This inflammation of adipose tissue is a key event in the pathogenesis of several obesity-related disorders, particularly insulin resistance. Here, we summarized existing model systems that mimic the situation of inflamed adipose tissue in vitro, most of them being murine. Importantly, we introduce our newly established human model system which combines the THP-1 monocytic cell line and the preadipocyte cell strain Simpson-Golabi-Behmel syndrome (SGBS). THP-1 cells, which originate from an acute monocytic leukemia, differentiate easily into macrophages in vitro. The human preadipocyte cell strain SGBS was recently introduced as a unique tool to study human fat cell functions. SGBS cells are characterized by a high capacity for adipogenic differentiation. SGBS adipocytes are capable of fat cell-specific metabolic functions such as insulin-stimulated glucose uptake, insulin-stimulated de novo lipogenesis and β-adrenergic-stimulated lipolysis and they secrete typical adipokines including leptin, adiponectin, and RBP4. Applying either macrophage-conditioned medium or a direct co-culture of macrophages and fat cells, our model system can be used to distinguish between paracrine and cell-contact dependent effects. In conclusion, we propose this model as a useful tool to study adipose inflammation in vitro. It represents an inexpensive, highly reproducible human system. The methods described here can be easily extended for usage of primary human macrophages and fat cells.