Low-Cost Label-Free Biosensing Bimetallic Cellulose Strip with SILAR-Synthesized Silver Core-Gold Shell Nanoparticle Structures.

We introduce a label-free biosensing cellulose strip sensor with surface-enhanced Raman spectroscopy (SERS)-encoded bimetallic core@shell nanoparticles. Bimetallic nanoparticles consisting of a synthesis of core Ag nanoparticles (AgNP) and a synthesis of shell gold nanoparticles (AuNPs) were fabricated on a cellulose substrate by two-stage successive ionic layer absorption and reaction (SILAR) techniques. The bimetallic nanoparticle-enhanced localized surface plasmon resonance (LSPR) effects were theoretically verified by computational calculations with finite element models of optimized bimetallic nanoparticles interacting with an incident laser source. Well-dispersed raspberry-like bimetallic nanoparticles with highly polycrystalline structure were confirmed through X-ray and electron analyses despite ionic reaction synthesis. The stability against silver oxidation and high sensitivity with superior SERS enhancement factor (EF) of the low-cost SERS-encoded cellulose strip, which achieved 3.98 × 108 SERS-EF, 6.1%-RSD reproducibility, and <10%-degraded sustainability, implicated the possibility of practical applications in high analytical screening methods, such as single-molecule detection. The remarkable sensitivity and selectivity of this bimetallic biosensing strip in determining aquatic toxicities for prohibited drugs, such as aniline, sodium azide, and malachite green, as well as monitoring the breast cancer progression for urine, confirmed its potential as a low-cost label-free point-of-care test chip for the early diagnosis of human diseases.

Exenatide Prevents Morphological and Structural Changes of Mitochondria Following Ischaemia-Reperfusion Injury.

BACKGROUND: Exenatide exerts cardioprotective effects by attenuating ischaemic reperfusion (IR) injury, possibly through activating the opening of mitochondrial ATP-sensitive potassium channels. We used atomic force microscopy (AFM) to investigate changes in mitochondrial morphology and properties in order to assess exenatide-mediated cardioprotection in IR injury. METHODS: We used an in vivo Sprague-Dawley rat IR model and ex vivo Langendorff injury model. In the left anterior descending artery (LAD) occlusion model, animals were randomly divided into three groups: sham-operated rats (Sham, n=5), IR-injured rats treated with placebo (IR, n=6), and IR-injured treated with exenatide (IR + EXE, n=6). For the Langendorff model, rats were randomly divided into two groups: IR injury with placebo (IR, n=4) and IR injury with exenatide (IR+EXE, n=4). Morphological and mechanical changes of mitochondria were analysed by AFM. RESULTS: Exenatide pre-treatment improved cardiac function as evidenced by improvement in echocardiographic results. The ratio of infarct area (IA) to risk area (RA) was significantly reduced in exenatide-treated rats. According to AFM, IR significantly increased the area of isolated mitochondria, indicative of mitochondrial swelling. Treatment with exenatide reduced the mitochondrial area and ameliorated the adhesion force of mitochondrial surfaces. CONCLUSIONS: Exenatide pre-treatment improves morphological and mechanical characteristics of mitochondria in response to IR injury in a rat model. These alterations in mitochondrial characteristics appear to play a cardioprotective role against IR injury.

Instrument-Free Synthesizable Fabrication of Label-Free Optical Biosensing Paper Strips for the Early Detection of Infectious Keratoconjunctivitides.

We introduce a surface-enhanced Raman scattering (SERS)-functionalized, gold nanoparticle (GNP)-deposited paper strip capable of label-free biofluid sensing for the early detection of infectious eye diseases. The GNP biosensing paper strip was fabricated by the direct synthesis and deposition of GNPs on wax-divided hydrophilic areas of a permeable porous substrate through a facile, power-free synthesizable, and highly reproducible successive ionic layer absorption and reaction (SILAR) technique. To maximize localized surface plasmon resonance-generated SERS activity, the concentration of the reactive solution and number of SILAR cycles were optimized by controlling the size and gap distance of GNPs and verified by computational modeling with geometrical hypotheses of Gaussian-estimated metallic nanoparticles. The responses of our SERS-functionalized GNP paper strip to Raman intensities exhibited an enhancement factor of 7.8 × 10(8), high reproducibility (relative standard deviation of 7.5%), and 1 pM 2-naphthalenethiol highly sensitive detection limit with a correlation coefficient of 0.99, achieved by optimized SILAR conditions including a 10/10 mM/mM HAuCl4/NaBH4 concentration and six SILAR cycles. The SERS-functionalized GNP paper is supported by a multivariate statistics-preprocessed machine learning-judged bioclassification system to provide excellent label-free chemical structure sensitivity for identifying infectious keratoconjunctivitis. The power-free synthesizable fabrication, label-free, rapid analysis, and high sensitivity feature of the SILAR-fabricated SERS-functionalized GNP biosensing paper strip makes it an excellent alternative in point-of-care applications for the early detection of various infectious diseases.

Intrinsic and extrinsic mechanical properties related to the differentiation of mesenchymal stem cells.

Diverse intrinsic and extrinsic mechanical factors have a strong influence on the regulation of stem cell fate. In this work, we examined recent literature on the effects of mechanical environments on stem cells, especially on differentiation of mesenchymal stem cells (MSCs). We provide a brief review of intrinsic mechanical properties of single MSC and examined the correlation between the intrinsic mechanical property of MSC and the differentiation ability. The effects of extrinsic mechanical factors relevant to the differentiation of MSCs were considered separately. The effect of nanostructure and elasticity of the matrix on the differentiation of MSCs were summarized. Finally, we consider how the extrinsic mechanical properties transfer to MSCs and then how the effects on the intrinsic mechanical properties affect stem cell differentiation.

Selective cytotoxic effect of non-thermal micro-DBD plasma.

Non-thermal plasma has been extensively researched as a new cancer treatment technology. We investigated the selective cytotoxic effects of non-thermal micro-dielectric barrier discharge (micro-DBD) plasma in cervical cancer cells. Two human cervical cancer cell lines (HeLa and SiHa) and one human fibroblast (HFB) cell line were treated with micro-DBD plasma. All cells underwent apoptotic death induced by plasma in a dose-dependent manner. The plasma showed selective inhibition of cell proliferation in cervical cancer cells compared to HFBs. The selective effects of the plasma were also observed between the different cervical cancer cell lines. Plasma treatment significantly inhibited the proliferation of SiHa cells in comparison to HeLa cells. The changes in gene expression were significant in the cervical cancer cells in comparison to HFBs. Among the cancer cells, apoptosis-related genes were significantly enriched in SiHa cells. These changes were consistent with the differential cytotoxic effects observed in different cell lines.

Matrilin-3 Role in Cartilage Development and Osteoarthritis.

The extracellular matrix (ECM) of cartilage performs essential functions in differentiation and chondroprogenitor cell maintenance during development and regeneration. Here, we discuss the vital role of matrilin-3, an ECM protein involved in cartilage development and potential osteoarthritis pathomechanisms. As an adaptor protein, matrilin-3 binds to collagen IX to form a filamentous network around cells. Matrilin-3 is an essential component during cartilage development and ossification. In addition, it interacts directly or indirectly with transforming growth factor ß (TGF-ß), and bone morphogenetic protein 2 (BMP2) eventually regulates chondrocyte proliferation and hypertrophic differentiation. Interestingly, matrilin-3 increases interleukin receptor antagonists (IL-Ra) in chondrocytes, suggesting its role in the suppression of IL-1ß-mediated inflammatory action. Matrilin-3 downregulates the expression of matrix-degrading enzymes, such as a disintegrin metalloproteinase with thrombospondin motifs 4 (ADAMTS4) and ADAMTS5, matrix metalloproteinase 13 (MMP13), and collagen X, a hypertrophy marker during development and inflammatory conditions. Matrilin-3 essentially enhances collagen II and aggrecan expression, which are required to maintain the tensile strength and elasticity of cartilage, respectively. Interestingly, despite these attributes, matrilin-3 induces osteoarthritis-associated markers in chondrocytes in a concentration-dependent manner. Existing data provide insights into the critical role of matrilin-3 in inflammation, matrix degradation, and matrix formation in cartilage development and osteoarthritis.

Enhancement of Matrix Metalloproteinase-2 (MMP-2) as a Potential Chondrogenic Marker during Chondrogenic Differentiation of Human Adipose-Derived Stem Cells.

Human adipose-derived stem cells (hASCs) have a capacity to undergo adipogenic, chondrogenic, and osteogenic differentiation. Recently, hASCs were applied to various fields including cell therapy for tissue regeneration. However, it is hard to predict the direction of differentiation of hASCs in real-time. Matrix metalloproteinases (MMPs) are one family of proteolytic enzymes that plays a pivotal role in regulating the biology of stem cells. MMPs secreted by hASCs are expected to show different expression patterns depending on the differentiation state of hASCs because biological functions exhibit different patterns during the differentiation of stem cells. Here, we investigated proteolytic enzyme activity, especially MMP-2 activity, in hASCs during their differentiation. The activities of proteolytic enzymes and MMP-2 were higher during chondrogenic differentiation than during adipogenic and osteogenic differentiation. During chondrogenic differentiation, mRNA expression of MMP-2 and the level of the active form of MMP-2 were increased, which also correlated with Col II. It is concluded that proteolytic enzyme activity and the level of the active form of MMP-2 were increased during chondrogenic differentiation, which was accelerated in the presence of Col II protein. According to our findings, MMP-2 could be a candidate maker for real-time detection of chondrogenic differentiation of hASCs.

Label-free biochemical analytic method for the early detection of adenoviral conjunctivitis using human tear biofluids.

Cell culture and polymerase chain reaction are currently regarded as the gold standard for adenoviral conjunctivitis diagnosis. They maximize sensitivity and specificity but require several days to 3 weeks to get the results. The aim of this study is to determine the potential of Raman spectroscopy as a stand-alone analytical tool for clinical diagnosis of adenoviral conjunctivitis using human tear fluids. A drop-coating deposition surface enhanced Raman scattering (DCD-SERS) method was identified as the most effective method of proteomic analysis in tear biofluids. The proposed DCD-SERS method (using a 2-µL sample) led to Raman spectra with high reproducibility, noise-independence, and uniformity. Additionally, the spectra were independent of the volume of biofluids used and detection zones, including the ring, middle, and central zone, with the exception of the outer layer of the ring zone. Assessments with an intensity ratio of 1242-1342 cm(-1) achieved 100% sensitivity and 100% specificity in the central zone. Principal component analysis assessments achieved 0.9453 in the area under the receiver operating characteristic curve (AUC) as well as 93.3% sensitivity and 94.5% specificity in the central zone. Multi-Gaussian peak assessments showed that the differences between these two groups resulted from the reduction of the amide III α-helix structures of the proteins. The presence of adenovirus in tear fluids could be detected more accurately in the center of the sample than in the periphery. The DCD-SERS technique allowed for high chemical structure sensitivity without additional tagging or chemical modification, making it a good alternative for early clinical diagnosis of adenoviral conjunctivitis. Therefore, we are hopeful that the DCD-SERS method will be approved for use in ophthalmological clinics in the near future.

Effects of sildenafil on nanostructural and nanomechanical changes in mitochondria in an ischaemia-reperfusion rat model.

Sildenafil exerts cardioprotective effects by activating the opening of mitochondrial ATP-sensitive potassium channels to attenuate ischaemia-reperfusion (IR) injury. In the present study, we used atomic force microscopy (AFM) to investigate changes in mitochondrial morphology and properties to assess sildenafil-mediated cardioprotection in a rat myocardial infarction model. To investigate the cardioprotective effects of sildenafil, we used an in vivo Sprague-Dawley rat model of IR. Rats were randomly divided into three groups: (i) sham-operated rats (control; n = 5); (ii) IR-injured rats treated with vehicle (normal saline; IR; n = 10); and (iii) IR-injured rats treated with 0.75 mg/kg, i.p., sildenafil (IR + Sil; n = 10). Morphological and mechanical changes to mitochondria were analysed by AFM. Infarct areas were significantly reduced in sildenafil-treated rats (7.8 ± 3.9% vs 20.4 ± 7.0% in the sildenafil-treated and untreated IR groups, respectively; relative reduction 62%; P < 0.001). Analysis of mitochondria by AFM showed that IR injury significantly increased the areas of isolated mitochondria compared with control (24 150 ± 18 289 vs 1495 ± 1139 nm(2) , respectively; P < 0.001), indicative of mitochondrial swelling. Pretreatment with sildenafil before IR injury reduced the mitochondrial areas (7428 ± 3682 nm(2) ; P < 0.001; relative reduction 69.2% compared with the IR group) and ameliorated the adhesion force of mitochondrial surfaces. Together, these results suggest that sildenafil has cardioprotective effects against IR injury in a rat model by improving the morphological and mechanical characteristics of mitochondria.

Medical applications of atomic force microscopy and Raman spectroscopy.

This paper reviews the recent research and application of atomic force microscopy (AFM) and Raman spectroscopy techniques, which are considered the multi-functional and powerful toolkits for probing the nanostructural, biomechanical and physicochemical properties of biomedical samples in medical science. We introduce briefly the basic principles of AFM and Raman spectroscopy, followed by diagnostic assessments of some selected diseases in biomedical applications using them, including mitochondria isolated from normal and ischemic hearts, hair fibers, individual cells, and human cortical bone. Finally, AFM and Raman spectroscopy applications to investigate the effects of pharmacotherapy, surgery, and medical device therapy in various medicines from cells to soft and hard tissues are discussed, including pharmacotherapy--paclitaxel on Ishikawa and HeLa cells, telmisartan on angiotensin II, mitomycin C on strabismus surgery and eye whitening surgery, and fluoride on primary teeth--and medical device therapy--collagen cross-linking treatment for the management of progressive keratoconus, radiofrequency treatment for skin rejuvenation, physical extracorporeal shockwave therapy for healing of Achilles tendinitis, orthodontic treatment, and toothbrushing time to minimize the loss of teeth after exposure to acidic drinks.

Cell viability, adhesion and function of RAW 264.7 macrophages on fluorinated xerogel-derived nitric oxide permeable membrane for the application of cellular sensing.

Organically modified xerogels have an advantage over gas sensing applications due to their open, rigid structure and hydrophobicity. Here we evaluated the biocompatibility of xerogel-derived nitric oxide (NO) permeable membranes modified with fluorinated functional groups for application in cellular sensing by growing RAW 264.7 macrophages on them. We examined the cell viability, adhesion and growth of RAW 264.7 macrophages on NO permselective membrane and other cell-adhesive matrices, poly L-lysine and collagen. The surface roughness of each membrane was obtained from topographic atomic force microscopy (AFM) images. In addition, we measured the level of NO release of RAW 264.7 macrophages by lipopolysaccharide (LPS) stimulation using a Griess assay to confirm the function of cells. The fluorinated xerogel-derived membrane had a very smooth surface with rms roughness 2.1 Å and did not show cytotoxic effects in RAW 264.7 macrophages. As a result, the morphology and function of adhering RAW 264.7 macrophage showed no differences from those of other cell-adhesive membranes. Finally, we successfully detected NO release in RAW 264.7 macrophages stimulated by LPS, using a planar-type xerogel-derived NO sensor. Therefore, we suggest that fluorinated xerogel-derived membrane could be used as both a NO permeable and cell-adhesive membrane for cellular sensing applications.

Vertically aligned carbon nanotube emitter on metal foil for medical X-ray imaging.

A simple method is proposed for growing vertically aligned carbon nanotubes on metal foil using the triode direct current plasma-enhanced chemical vapor deposition (PECVD). The carbon nanotube (CNT) electron emitter was fabricated using fewer process steps with an acid treated metal substrate. The CNT emitter was used for X-ray generation, and the X-ray image of mouse's joint was obtained with an anode current of 0.5 mA at an anode bias of 60 kV. The simple fabrication of a well-aligned CNT with a protection layer on metal foil, and its X-ray application, were studied.

Nanostructural and nanomechanical responses of collagen fibrils in the collagenase-induced Achilles tendinitis rat model.

Achilles tendons are vulnerable to acute or chronic injuries that lead to inflammation. We investigated nanostructural and nanomechanical changes in collagen fibrils from rat Achilles tendons over a period of 9 weeks after injury using atomic force microscopy (AFM). To evaluate the nanostructural changes in Achilles tendons, we measured the diameter and D-banding of collagen fibrils by AFM. And the adhesion forces, which were related to cross-linking of collagen, were calculated from the retraction process of a force-distance curve. We successfully observed the time course of changes in collagen fibrils during healing using AFM. The diameters and D-banding in healed tendons were similar to those of uninjured tendons at 9 weeks after injury, but the adhesion forces remained different from those of uninjured tendons. Our AFM results depicted the minute changes in Achilles tendon surface by natural healing quite well, even drawbacks to naturally healed tendon. Understanding changes in collagen cross-linking and structure while healing will lead to better understanding of healing mechanisms and subsequent improvements in treatment. And AFM can be applied as powerful tool to evaluate structural and property changes in collagen fibrils before and after injury and/or treatment in Achilles tendon.

Analysis of aging effects on chemical property of human hair by Fourier transform infrared spectroscopy.

BACKGROUND: In the previous work, we investigated the aging effect on morphology and mechanical property of the hair by using atomic force microscopy. OBJECTIVES: The effects of aging on chemical properties of human hair were investigated by Fourier transform infrared (FT-IR) spectroscopy. METHODS: Healthy hair samples with no diseases were collected from 60 Koreans (30 males and 30 females) and they were grouped by age: 1-10, 11-20, 21-30, 31-40, 41-50, and 51-60 years. RESULTS: The characteristic parameters of FT-IR absorbance bands including center frequency, half width, height, and area were analyzed using the Gaussian model. To quantitatively analyze the chemical composition of hair, the height and area of all bands in the spectra were normalized to the amide I centered at 1652-1659 and 1654-1658 cm(-1), for male and female hairs, respectively. In all male and female hairs, the spectra of specific components of the hair keratin showed to have the same dependence on aging. The center positions of the bands arising from amide A, CH(3) mode, and amide I were altered by aging. The female hair contains more cystein than the male hair. Changes in the amount of amide II and amide A by aging were more significant in male hair than in female hair. CONCLUSIONS: The changes in chemical components of the hair according to the ages were shown at the inflection point at 30 s.

A comparative study of hair shafts in scalp psoriasis and seborrheic dermatitis using atomic force microscopy.

BACKGROUND: As the inflammatory scalp conditions share similar clinical manifestations of scaling, inflammation, and pruritus, the differential diagnosis of these lesions; especially between scalp psoriasis (SP) and seborrheic dermatitis (SD) is sometimes difficult. OBJECTIVES: The aim of this study was to investigate the differences on the hair surface in SP and SD for a clinical diagnosis, using atomic force microscopy (AFM). METHODS: The hair shafts of 14 patients and 28 patients with SP and SD respectively, were taken from the lesional region. Hairs from healthy adults not having any hair diseases were also examined in the same way for the controls. Surface characteristics of SP and SD-affected hair shafts such as, pitting, scale thickness, and roughness, were observed on the AFM images. RESULTS: One hundred percentage and four percentage of the patients with SP and SD respectively had macropits on their hair shafts. In both the SP and SD-affected hairs, the scale thickness was more than 4-fold than that in the control hairs. The surface of SP-affected hairs was rougher than that of SD-affected and control hairs. CONCLUSION: The differences in hair shafts between SP and SD were investigated noninvasively using AFM. The presence of macropits could be helpful in the differentiation between SP and SD.

Structural and biomechanical effects of photooxidative collagen cross-linking with photosensitizer riboflavin and 370 nm UVA light on human corneoscleral tissues.

This study quantitatively investigated the immediate effects of a photooxidative collagen cross-linking treatment with photosensitizer riboflavin (RF) and 370 nm UVA light in in vitro human corneoscleral collagen fibrils using histology, thickness, scanning electron microscopy, and atomic force microscopy analyses. Twenty 8 x 2 mm corneoscleral strips were dissected sagittally from donor tissue using a scalpel. Four parameters were investigated, including the density, thickness, adhesion force, and stiffness of corneoscleral tissues before and after the collagen cross-linking treatment. The RFUVA-catalyzed collagen cross-linking treatment led to an increase in the density of both corneal (8%) and scleral (23%) stromal collagens. However, there was no difference in corneoscleral thickness. Furthermore, RFUVA-catalyzed collagen cross-linking treatment led to an increased biomechanical response of corneosclera: 25 and 8% increases in corneoscleral stiffness, and 24 and 22% increases in corneoscleral adhesion force. The collagen cross-linking treatment through RF-sensitized photoreaction may cause structural and biomechanical changes in the collagen fibril network of the cornea and the sclera. This is due to narrowing of the interfibrillar spacing and the stromal edema.

Short-term response of mitomycin C on the human rectus muscle following strabismus surgery: histological, ultrastructural, and biomechanical evaluation.

This study investigated the inflammatory effect of intraoperative mitomycin C (MMC) on adhesion reformation in human rectus muscles. Ten consecutive patients who underwent medial rectus resection had their postoperative rectus muscles divided into two groups: control group (n = 10) and MMC group (n = 10). In the MMC group, the muscle was soaked for 2 min with MMC, prepared as a 0.2 mg/mL (0.02%) solution. The 0.02% MMC reactions were examined using histological analysis with hematoxylin-eosin (inflammatory response) and Masson's trichrome (collagen fibrils), immunoreactivities of cyclooxygenase-II (inflammatory response), and collagen type I and III, scanning electron microscopy analysis to quantify the diameter and D-periodicity of collagen fibrils, and atomic force microscopy analysis to quantify the diameter, D-periodicity, and adhesion force of collagen fibrils. The rectus muscles treated with 0.02% MMC showed a significantly increased inflammatory response (p < 0.05), increased collagen density (p < 0.0001), increased fibril diameter (p < 0.001 or p < 0.05), and decreased fibril adhesion force (p < 0.005) compared to the rectus muscles in the control group. MMC simultaneously caused an inflammatory response as well as nanostructural and biomechanical property changes in the collagen fibril network.

Structural response of human corneal and scleral tissues to collagen cross-linking treatment with riboflavin and ultraviolet A light.

High success rates in clinical trials on keratoconic corneas suggest the possibility of efficient treatment against myopic progression. This study quantitatively investigated the in vitro ultrastructural effects of a photooxidative collagen cross-linking treatment with photosensitizer riboflavin and UVA light in human corneo-scleral collagen fibrils. A total of 30.8 × 2 mm corneo-scleral strips from donor tissue were sagittally dissected using a scalpel. The five analytic parameters namely fibril density, fibril area, corneo-scleral thickness, fibril diameter, and fibril arrangement were investigated before and after riboflavin-UVA-catalyzed collagen cross-linking treatment. Collagen cross-linking effects were measured at the corneo-scleral stroma and were based on clinical corneal cross-linking procedures. The structural response levels were assessed by histology, digital mechanical caliper measurement, scanning electron microscopy, and atomic force microscopy. Riboflavin-UVA-catalyzed collagen cross-linking treatment led to an increase in the area, density, and diameters of both corneal (110, 112, and 103 %) and scleral (133, 133, and 127 %) stromal collagens. It also led to increases in corneal (107 %) and scleral (105 %) thickness. Collagen cross-linking treatment through riboflavin-sensitized photoreaction may cause structural property changes in the collagen fibril network of the cornea and sclera due to stromal edema and interfibrillar spacing narrowing. These changes were particularly prominent in the sclera. This technique can be used to treat progressive keratoconus in the cornea as well as progressive myopia in the sclera. Long-term collagen cross-linking treatment of keratoconic and myopic progression dramatically improves weakened corneo-scleral tissues.

Antioxidants, like coenzyme Q10, selenite, and curcumin, inhibited osteoclast differentiation by suppressing reactive oxygen species generation.

Coenzyme Q10 (CoQ10), selenium, and curcumin are known to be powerful antioxidants. Osteoclasts are capable of resorbing mineralized bone and excessive bone resorption by osteoclasts causes bone loss-related diseases. During osteoclast differentiation, the reactive oxygen species (ROS) acts as a secondary messenger on signal pathways. In this study, we investigated whether antioxidants can inhibit RANKL-induced osteoclastogenesis through suppression of ROS generation and compared the relative inhibitory activities of CoQ10, sodium selenite, and curcumin on osteoclast differentiation. We found that antioxidants markedly inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells in both bone marrow-derived monocytes (BMMs) and RAW 264.7 cells. Antioxidants scavenged intracellular ROS generation within osteoclast precursors during RANKL-stimulated osteoclastogenesis. These also acted to significantly suppress the gene expression of NFATc1, TRAP, and osteoclast-associated immunoglobulin-like receptor (OSCAR), which are genetic markers of osteoclast differentiation in a dose-dependent manner. These antioxidants also suppressed ROS-induced IκBα signaling pathways for osteoclastogenesis. Specially, curcumin displayed the highest inhibitory effect on osteoclast differentiation when concentrations were held constant. Together, CoQ10, selenite, and curcumin act as inhibitors of RANKL-induced NFATc1 which is a downstream event of NF-κB signal pathway through suppression of ROS generation, thereby suggesting their potential usefulness for the treatment of bone disease associated with excessive bone resorption.

Real time measurement of myocardial oxygen dynamics during cardiac ischemia-reperfusion of rats.

Because oxygen plays a critical role in the pathophysiology of myocardial injury during subsequent reperfusion, as well as ischemia, the accurate measurement of myocardial oxygen tension is crucial for the assessment of myocardial viability by ischemia-reperfusion (IR) injury. Therefore, we utilized a sol-gel derived electrochemical oxygen microsensor to monitor changes in oxygen tension during myocardial ischemia-reperfusion. We also analyzed differences in oxygen tension recovery in post-ischemic myocardium depending on ischemic time to investigate the correlation between recovery parameters for oxygen tension and the severity of IR injury. An oxygen sensor was built using a xerogel-modified platinum microsensor and a coiled Ag/AgCl reference electrode. Rat hearts were randomly divided into 5 groups: control (0 min ischemia), I-10 (10 min ischemia), I-20 (20 min ischemia), I-30 (30 min ischemia), and I-40 (40 min ischemia) groups (n = 3 per group, respectively). After the induction of ischemia, reperfusion was performed for 60 min. As soon as the ischemia was initiated, oxygen tension rapidly declined to near zero levels. When reperfusion was initiated, the changes in oxygen tension depended on ischemic time. The normalized peak level of oxygen tension during the reperfusion episode was 188 ± 27 in group I-10, 120 ± 24 in group I-20, 12.5 ± 10.6 in group I-30, and 1.24 ± 1.09 in group I-40 (p < 0.001, n = 3, respectively). After 60 min of reperfusion, the normalized restoration level was 129 ± 30 in group I-10, 88 ± 4 in group I-20, 3.40 ± 4.82 in group I-30, and 0.99 ± 0.94 in group I-40 (p < 0.001, n = 3, respectively). The maximum and restoration values of oxygen tension in groups I-30 and I-40 after reperfusion were lower than pre-ischemic values. In particular, oxygen tension in the I-40 group was not recovered at all. These results were also demonstrated by TTC staining. We suggest that these recovery parameters could be utilized as an index of tissue injury and severity of ischemia. Therefore, quantitative measurements of oxygen tension dynamics in the myocardium would be helpful for evaluation of the cardioprotective effects of therapeutic treatments such as drug administration.