Lifetime and diffusion distance of singlet oxygen in air under everyday atmospheric conditions.

Singlet oxygen is a toxic chemical but powerful oxidant, exploited in many chemical and biological applications. However, the lifetime of singlet oxygen in air under atmospheric conditions is yet to be known. This has limited safe usage of singlet oxygen in air, despite being a strong antimicrobial agent with the unique property of relaxing to breathable oxygen after serving its purpose. Here, we solve this long-standing problem by combining experimental and theoretical research efforts; we generate singlet oxygen using a photosensitizer at a local source and monitor the time-dependent extent of singlet oxygen reaction with probe molecules at a detector, precisely controlling the detector distance from the source. To explain our experimental results, we employ a theoretical model that fully accounts for singlet oxygen diffusion, radiative and nonradiative relaxations, and the bimolecular reaction with probe molecules at the detector. For all cases investigated, our model, with only two adjustable parameters, provides an excellent quantitative explanation of the experiment. From this analysis, we extract the lifetime of singlet oxygen in the air to be 2.80 s at 23 °C under 1 atm, during which time singlet oxygen diffuses about 0.992 cm. The correctness of this estimation is confirmed by a simple mean-first-passage time analysis of the maximum distance singlet oxygen can reach from the source. We also confirm the sterilization effects of singlet oxygen for distances up to 0.6-0.8 cm, depending on the bacteria strain in question, between the bacteria and the singlet oxygen source.

Smart Hybrid Nanocomposite for Photodynamic Inactivation of Cancer Cells with Selectivity.

Photodynamic therapy has been efficiently applied for cancer therapy. Here, we have fabricated the folic acid (FA)- and pheophorbide A (PA)-conjugated FA/PA@Fe3O4 nanoparticle (smart hybrid nanocomposite, SHN) to enhance the photodynamic inactivation (PDI) of specific cancer cells. SHN coated with the PDI agent is designed to have selectivity for the folate receptor (FR) expressed on cancer cells. Structural characteristics and morphology of the fabricated MNPs were studied with X-ray diffraction and scanning electron microscopy. The photophysical properties of SHN were investigated with absorption, emission spectroscopies, and Fourier transform infrared spectroscopy. In addition, the magnetic property of Fe3O4 nanoparticle (MNP) can be utilized for the collection of SHNs by an external magnetic field. The photofunctionality was given by the photosensitizer, PA, which generates reactive oxygen species by irradiation of visible light. Generation of singlet oxygen was directly evaluated with time-resolved phosphorescence spectroscopy. Biocompatibility and cellular interaction of SHN were also analyzed by using various cancer cells, such as KB, HeLa, and MCF-7 cells which express different levels of FR on the surface. Cellular adsorption and the PDI effect of SHN on the various cancer cells in vitro were correlated well with the surface expression levels of FR, suggesting potential applicability of SHN on specific targeting and PDI of FR-positive cancers.

Study of Singlet Oxygen Dynamics on Silicon Polymer Matrix.

We report a detailed analysis of singlet oxygen generated from the photofunctional polymer film (PFPF) matrix which is the silicone polymer film (PDMS) embedded with a photosensitizer. Activation and deactivation dynamics of singlet oxygen generated from PFPFs were investigated with time-resolved phosphorescence spectroscopy. The singlet oxygen generated from PFPFs was dissipated into three different regions of the polymer matrix; the inside (component A), the surface (component B), and the outside (component C). According to the deactivation dynamics of singlet oxygen in the polymer matrix, the components B and C are expected to be more important for various applications.

Far-Infrared Irradiation Inhibits Adipogenic Differentiation and Stimulates Osteogenic Differentiation of Human Tonsil-Derived Mesenchymal Stem Cells: Role of Protein Phosphatase 2B.

BACKGROUND/AIMS: Far-infrared (FIR) irradiation has been reported to exhibit various biological effects including improvement of cardiovascular function. However, its effect on the differentiation of stem cells has not been studied. Using tonsil-derived mesenchymal stem cells (TMSC), we examined whether and how FIR irradiation affects adipogenic or osteogenic differentiation. METHODS: TMSC were exposed to FIR irradiation (3-25 µm wavelength) for various times (0, 30, or 60 min), and then adipogenic or osteogenic differentiation was induced for 14 days with its respective commercially available differentiation medium. At the end of the differentiation, the cells were stained using Oil red O or Alizarin red S solution, and the expression of differentiation-specific proteins was analyzed by western blotting. RESULTS: FIR irradiation did not alter cell viability or the expression of MSC-specific surface antigens (CD14, CD34, CD45, CD73, CD90, and CD105) in TMSC. However, FIR irradiation significantly inhibited adipogenic differentiation of TMSC, as evidenced by decreased Oil red O staining as well as protein expression of peroxisome proliferator-activated receptor γ and fatty acid binding protein 4. In contrast, FIR irradiation induced osteogenic differentiation, as evidenced by increased Alizarin red S staining as well as protein expression of osteocalcin and alkaline phosphatase. Treatment with heat alone did not inhibit the adipogenic differentiation of TMSC, suggesting that the inhibitory effect on adipogenic differentiation was not due to heat induced by FIR irradiation. However, heat alone did stimulate osteogenic differentiation, but to a lesser extent than FIR irradiation. Furthermore, FIR irradiation increased intracellular Ca²âº levels and the activity of protein phosphatase 2B (PP2B) in TMSC. Treatment with cyclosporin A, a specific PP2B inhibitor, reversed the inhibitory effect of FIR irradiation on adipogenic differentiation of TMSC, but had no effect on osteogenic differentiation. CONCLUSION: Our data demonstrate that FIR irradiation inhibits adipogenic differentiation but enhances osteogenic differentiation of TMSC; the inhibitory effect on adipogenic differentiation is non-thermal and mediated at least in part by activation of Ca²âº-dependent PP2B.

Target-oriented photofunctional nanoparticles (TOPFNs) for selective photodynamic inactivation of Methicillin-resistant Staphylococcus aureus (MRSA).

To inactivate methicillin-resistant Staphylococcus aureus (MRSA) with minimum damage to host cells and tissue, target-oriented photofunctional nanoparticles (TOPFNs) were fabricated and characterized. MRSA is a predominant infective pathogen even in hospital and non-hospital environments due to its ability to develop high levels of resistance to several classes of antibiotics through various pathways. To solve this major problem, photodynamic inactivation (PDI) method applies to treat antibiotic-resistant bacteria. PDI involves the photosensitizer (PS) and light with a specific wavelength to be able to apply for a non-invasive therapeutic procedure to treat pathogenic bacteria by inducing apoptosis or necrosis of microorganisms. However, most current PDI researches have suffered from the instability of PDI agents in the biological environment due to the lack of selectivity and low solubility of PDI agents, which leads to the low PDI efficiency. In this study, the TOPFNs were fabricated by an esterification reaction to introduce hematoporphyrin (HP) and MRSA antibody to the surface of Fe3O4 nanoparticles. The TOPFNs were designed as dispersible PDI agent in biological condition, which was effectively used for selectively capturing and killing of MRSA. The capture efficiency TOPFNs was compared with PFNs as a negative control. The results showed that the capture efficiency of TOPFNs and PFNs was 95.55% and 6.43% in MRSA and L-929 cell mixed condition, respectively. And TOPFNs have a selective killing ability for MRSA with minimum damage to L-929 cells. Furthermore, PDI effect of TOPFNs was evaluated on the mice in vivo condition in order to check the possibility of practical medical application.

Identifying the KAT6B Mutation via Diagnostic Exome Sequencing to Diagnose Say-Barber-Biesecker-Young-Simpson Syndrome in Three Generations of a Family.

Diagnostic exome sequencing (DES) is a powerful tool to analyze the pathogenic variants leading to development delay (DD) and intellectual disability (ID). Recently, heterozygous de novo mutation of the histone acetyltransferase encoding gene KAT6B has been recognized as causing a syndrome with congenital anomalies and intellectual disability, namely Say-Barber-Biesecker-Young-Simpson (SBBYS) syndrome. Here we report a case of SBBYS syndrome in a third generation Korean family affected with a missense mutation in KAT6B, c.2292C>T p.(His767Tyr) identified by DES. This is the first confirmed familial inherited mutation of the KAT6B reported worldwide. Our case emphasizes again the importance of basic physical examination and taking a family history. Furthermore, advances in genetic diagnostic tools are becoming key to identifying the etiology of DD and ID. This allows a physiatrist to predict the disease's clinical evolution with relative certainty, and offer an appropriate rehabilitation plan for patients.

Eradication of Plasmodium falciparum from Erythrocytes by Controlled Reactive Oxygen Species via Photodynamic Inactivation Coupled with Photofunctional Nanoparticles.

We investigated the antimalarial effect of photodynamic inactivation (PDI) coupled with magnetic nanoparticles (MNPs) as a potential strategy to combat the emergence of drug-resistant malaria and resurgence of malaria after treatment. Because the malarial parasite proliferates within erythrocytes, PDI agents need to be taken up by erythrocytes to eradicate the parasite. We used photofunctional MNPs as the PDI agent because nanosized particles were selectively taken up by Plasmodium-infected erythrocytes and remained within the intracellular space due to the enhanced permeability and retention effect. Also, the magnetism of Fe3O4 nanoparticles can easily be utilized for the collection of photofunctional nanoparticles (PFNs), and the uptaken PFNs infected the erythrocytes after photodynamic treatment with external magnetics. Photofunctionality was provided by a photosensitizer, namely, pheophorbide A, which generates reactive oxygen species (ROS) under irradiation. PAs were covalently bonded to the surface of the MNPs. The morphology and structural characteristics of the MNPs were investigated by scanning electron microscopy and X-ray diffraction (XRD), whereas the photophysical properties of the PFNs were studied with Fourier transform infrared, absorption, and emission spectroscopies. Generation of singlet oxygen, a major ROS, was directly confirmed with time-resolved phosphorescence spectroscopy. To evaluate the ability of PFNs to kill malarial parasites, the PDI effect of PFNs was evaluated within the infected erythrocytes. Furthermore, malarial parasites were completely eradicated from the erythrocytes after PDI treatment using PFNs on the basis of an 8 day erythrocyte culture test.

Sensing Estrogen with Electrochemical Impedance Spectroscopy.

This study demonstrates the application feasibility of electrochemical impedance spectroscopy (EIS) in measuring estrogen (17ß-estradiol) in gas phase. The present biosensor gives a linear response (R2 = 0.999) for 17ß-estradiol vapor concentration from 3.7 ng/L to 3.7 × 10-4 ng/L with a limit of detection (3.7 × 10-4 ng/L). The results show that the fabricated biosensor demonstrates better detection limit of 17ß-estradiol in gas phase than the previous report with GC-MS method. This estrogen biosensor has many potential applications for on-site detection of a variety of endocrine disrupting compounds (EDCs) in the gas phase.

Controlled Delivery of Extracellular ROS Based on Hematoporphyrin-Incorporated Polyurethane Film for Enhanced Proliferation of Endothelial Cells.

The principle of photodynamic treatment (PDT) involves the administration of photosensitizer (PS) at diseased tissues, followed by light irradiation to produce reactive oxygen species (ROS). In cells, a moderate increase in ROS plays an important role as signaling molecule to promote cell proliferation, whereas a severe increase of ROS causes cell damage. Previous studies have shown that low levels of ROS stimulate cell growth through PS drugs-treating PDT and nonthermal plasma treatment. However, these methods have side effects which are associated with low tissue selectivity and remaining of PS residues. To overcome such shortcomings, we designed hematoporphyrin-incorporated polyurethane (PU) film induced generation of extracellular ROS with singlet oxygen and free radicals. The film can easily control ROS production rate by regulating several parameters including light dose, PS dose. Also, its use facilitates targeted delivery of ROS to the specific lesion. Our study demonstrated that extracellular ROS could induce the formation of intracellular ROS. In vascular endothelial cells, a moderated increase in intracellular ROS also stimulated cell proliferation and cell cycle progression by accurate control of optimum levels of ROS with hematoporphyrin-incorporated polymer films. This modulation of cellular growth is expected to be an effective strategy for the design of next-generation PDT.

Posterior Deltoid-to-Triceps Tendon Transfer for Elbow Extension in a Tetraplegia Patient: A Case Report.

In tetraplegia patients, activities of daily living are highly dependent on the remaining upper limb functions. In other countries, upper limb reconstruction surgery to improve function has been applied to diverse cases, but few cases have been reported in Korea. The current authors experienced a case of posterior deltoid-to-triceps tendon transfer and rehabilitation in a complete spinal cord injury with a C6 neurologic level, and we introduce the case-a 36-year-old man-with a literature review. The patient's muscle strength in C5 C6 muscles were normal, but C7 muscles were trace, and the Spinal Cord Independence Measure III (SCIM III) score was 24. The tendon of the posterior deltoid was transferred to the triceps brachii muscle, and then the patient received comprehensive rehabilitative treatment. His C7 muscle strength in the right upper extremity was enhanced from trace to fair, and his SCIM III score improved to 29.

A Crucial Role of Rh Substituent Ion in Photoinduced Internal Electron Transfer and Enhanced Photocatalytic Activity of CdS-Ti(5.2-x)/6 Rhx /2 O2 Nanohybrids.

The photocatalytic activity and photostability of CdS quantum dot (QD) can be remarkably enhanced by hybridization with Rh-substituted layered titanate nanosheet even at very low Rh substitution rate (<1%). Mesoporous CdS-Ti(5.2-x)/6 Rhx/2O2 nanohybrids are synthesized by a self-assembly of exfoliated Ti(5.2-x)/6 Rhx/2O2 nanosheets with CdS QDs. The partial substitution of Rh(3+)/Rh(4+) ions for Ti(4+) ions in layered titanate is quite effective in enhancing an electronic coupling between hybridized CdS and titanate components via the formation of interband Rh 4d states. A crucial role of Rh substituent ion in the internal electron transfer is obviously evidenced from in situ X-ray absorption spectroscopy showing the elongation of (RhO) bond under visible light irradiation. This is the first spectroscopic evidence for the important role of substituent ion in the photoinduced electron transfer of hybrid-type photocatalyst. The CdS-Ti(5.2-x)/6 Rhx/2O2 nanohybrids show much higher photocatalytic activity for H2 production and better photostability than do CdS and unsubstituted CdS-TiO2 nanohybrid. This result is ascribable to the enhancement of visible light absorptivity, the depression of electron-hole recombination, and the enhanced hole curing of CdS upon Rh substitution. The present study underscores that the hybridization with composition-controlled inorganic nanosheet provides a novel efficient methodology to optimize the photo-related functionalities of semiconductor nanocrystal.

The effect of post-stroke depression on rehabilitation outcome and the impact of caregiver type as a factor of post-stroke depression.

OBJECTIVE: To evaluate the effect of post-stroke depression (PSD) on rehabilitation outcome and to investigate the risk factors of PSD, especially, the role of caregivers type (family or professional) in subacute stroke patients. METHODS: Two hundred twenty-six stroke patients were enrolled retrospectively. All the subjects' basic characteristics, Korean version of the Beck Depression Inventory (K-BDI), Korean version of the Modified Barthel Index (K-MBI), and the modified Rankin Scale (mRS) were recorded when the patient was transferred into the Department of Rehabilitation Medicine and at the time of discharge. The results were statistically analyzed by using SPSS ver. 20.0. RESULTS: The patients' K-BDI score showed a significantly negative association with K-MBI at discharge (ß=-0.473, p<0.001) and a significantly positive association with the mRS score at discharge (ß=0.316, p<0.001). Patients with lesions on the left hemisphere (odds ratio [OR], 3.882; 95% confidence interval [CI], 1.726-8.733) and professional caregiver support (OR, 0.028; 95% CI, 0.012-0.065) had a higher rate of depression. CONCLUSION: Depression was prevalent in stroke patients, and it had a negative effect on patients' functional outcome. Patients who had a lesion on the right hemisphere had less depression. The type of caregiver was related to the incidence of subacute PSD, and family caregivers were found to lower the frequency of stroke patients' depression.

Functional manipulation of dendritic cells by photoswitchable generation of intracellular reactive oxygen species.

Reactive oxygen species (ROS) play an important role in cellular signaling as second messengers. However, studying the role of ROS in physiological redox signaling has been hampered by technical difficulties in controlling their generation within cells. Here, we utilize two inert components, a photosensitizer and light, to finely manipulate the generation of intracellular ROS and examine their specific role in activating dendritic cells (DCs). Photoswitchable generation of intracellular ROS rapidly induced cytosolic mobilization of Ca(2+), differential activation of mitogen-activated protein kinases, and nuclear translocation of NF-κB. Moreover, a transient intracellular ROS surge could activate immature DCs to mature and potently enhance migration in vitro and in vivo. Finally, we observed that intracellular ROS-stimulated DCs enhanced antigen specific T-cell responses in vitro and in vivo, which led to delayed tumor growth and prolonged survival of tumor-bearing mice when immunized with a specific tumor antigen. Therefore, a transient intracellular ROS surge alone, if properly manipulated, can cause immature DCs to differentiate into a motile state and mature forms that are sufficient to initiate adaptive T cell responses in vivo.

Short-term change of handgrip strength after trigger point injection in women with muscular pain in the upper extremities.

OBJECTIVE: To determine overall handgrip strength (HGS), we assessed the short-term change of HGS after trigger point injection (TPI) in women with muscular pain in the upper extremities by comparison with established pain scales. METHODS: The study enrolled 50 female patients (FMS with MPS group: 29 patients with combined fibromyalgia [FMS] and myofascial pain syndrome [MPS]; MPS group: 21 patients with MPS) who presented with muscular pain in the upper extremities at Konyang University Hospital. In addition, a total of 9 healthy women (control group) were prospectively enrolled in the study. We surveyed the three groups using the following established pain scales: the Fibromyalgia Impact Questionnaire (FIQ), the 36-Item Short Form Health Survey (SF-36), and the Short Form McGill Pain Questionnaire (MPQ). HGS was measured in both hands of study participants using a handgrip dynamometer. We performed TPI (0.5% lidocaine, total 10 mL, injected at the pain site of upper extremities). After 20 minutes, we remeasured the patient's HGS and MPQ score. RESULTS: ANOVA analysis was conducted among groups. Based on Tukey multiple comparison test, the majority of FIQ and SF-36 subscales, total FIQ and SF-36 scores, MPQ and HGS were significantly different between FMS with MPS and the other groups. There was no statistically significant difference between MPS and control groups. Higher HGS was positively associated with enhanced physical function, negatively associated with total FIQ and MPQ scores, and positively associated with the total SF-36 score calculated using Spearman correlation. Post-TPI MPQ decreased and HGS increased. In patient groups, a negative correlation was found between MPQ and HGS. CONCLUSION: The HGS test might potentially be a complementary tool in assessing the short-term treatment effects of women with muscular pain in the upper extremities.

Molecular epidemiology of Pseudomonas aeruginosa clinical isolates from Korea producing ß-lactamases with extended-spectrum activity.

This study was performed to investigate the prevalence and molecular epidemiology of Pseudomonas aeruginosa isolates from Korea that produce enzymes with extended-spectrum (ES) activity to ß-lactams. A total of 205 non-duplicate P. aeruginosa clinical isolates were collected from 18 university hospitals in Korea. PCR and sequencing experiments were performed to identify genes encoding ß-lactamases. PCR mapping and sequencing of the regions surrounding the ß-lactamase genes were performed. Multilocus sequence typing experiments were performed. The most common sequence type (ST) was ST235 (n = 96), and 2 single-locus variants of ST235, ST1015 (n = 1) and ST1162 (n = 1), were also identified. These 3 STs were grouped as a clonal complex (CC), CC235. The remaining 107 isolates were identified as 59 different STs. Isolates belonging to CC235 showed higher rates of non-susceptibility to imipenem (85.4% versus 47.7%) and meropenem (92.7% versus 52.3%) compared to non-CC235 isolates. All the metallo-ß-lactamase (MBL)-producing isolates were identified as CC235, except for 1 ST591. Genes encoding OXA-17 and OXA-142 were detected in 1 isolate and 4 isolates of CC235, respectively; while the bla(SHV-12) gene was detected in 4 non-CC235 isolates. Class A and D ß-lactamases with ES activity play a role in acquiring ceftazidime resistance in P. aeruginosa in Korea. Production of IMP-6 and VIM-2 MBLs is the main mechanisms in acquiring resistance to ceftazidime and carbapenems in P. aeruginosa isolates in Korea. Clonal spread of P. aeruginosa CC235 may be an important conduit for the dissemination of MBL genes in Korea.

Comparison of pulsed-field gel electrophoresis & repetitive sequence-based PCR methods for molecular epidemiological studies of Escherichia coli clinical isolates.

BACKGROUND & OBJECTIVES: PFGE, rep-PCR, and MLST are widely used to identify related bacterial isolates and determine epidemiologic associations during outbreaks. This study was performed to compare the ability of repetitive sequence-based PCR (rep-PCR) and pulsed-field gel electrophoresis (PFGE) to determine the genetic relationships among Escherichia coli isolates assigned to various sequence types (STs) by two multilocus sequence typing (MLST) schemes. METHODS: A total of 41 extended-spectrum ß-lactamase- (ESBL-) and/or AmpC ß-lactamase-producing E. coli clinical isolates were included in this study. MLST experiments were performed following the Achtman's MLST scheme and the Whittam's MLST scheme, respectively. Rep-PCR experiments were performed using the DiversiLab system. PFGE experiments were also performed. RESULTS: A comparison of the two MLST methods demonstrated that these two schemes yielded compatible results. PFGE correctly segregated E. coli isolates belonging to different STs as different types, but did not group E. coli isolates belonging to the same ST in the same group. Rep-PCR accurately grouped E. coli isolates belonging to the same ST together, but this method demonstrated limited ability to discriminate between E. coli isolates belonging to different STs. INTERPRETATION & CONCLUSIONS: These results suggest that PFGE would be more effective when investigating outbreaks in a limited space, such as a specialty hospital or an intensive care unit, whereas rep-PCR should be used for nationwide or worldwide epidemiology studies.

Synthesis of Fe3O4-ZnS/AgInS2 composite nanoparticles using a hydrophobic interaction.

Magnetic nanoparticles and fluorescent quantum dots (QDs) can make many effective applications in biomedical system. Here, we demonstrated one way of synthetic method and its surface modification to use for biomedical applications. Fe3O4 nanoparticles are well known as magnetic materials and its magnetic property can be used in magnetic resonance imaging (MRI), cell detection. QDs as a fluorescent probes, make cell labeling and in vivo imaging possible. ZnS/AgInS2 QDs have a lower toxicity than other QDs (CdSe, CdTe, CdS). We combined two nanoparticles by hydrophobic interaction in their ligands. The prepared fluorescent magnetic composite particles were modified with CTAB-TEOS. The surface modified composite has a low cytotoxicity and these biocompatible particles will provide many possibilities in biomedical system.

Photoluminescent nanographitic/nitrogen-doped graphitic hollow shells as a potential candidate for biological applications.

Water-dispersible graphitic hollow spheres were synthesized using a soft chemical route under hydrothermal conditions by glucose carbonization using a magnetite/silica-encapsulated core-shell sphere as a template. Carbonization on the templates happens as the magnetite core is partially or completely eliminated depending on the reaction conditions. Therefore, nano-sized graphitic hollow spheres or magnetite-core-encapsulated graphitic shells could be obtained. Also nitrogen-doped graphitic spheres were synthesized by a hydrothermal reaction. The graphitic and nitrogen-doped graphitic spheres show wavelength dependent photoluminescence in 300-600 nm range. The photoluminescence seems to depend on the fraction of the sp2 domains and N-doping, therefore, tunable PL emission can be achieved by controlling the nature of sp2 sites. In addition the cellular uptake of the graphitic hollow spheres was evaluated in human HeLa cells, demonstrating its main localization in the cytoplasm. A blue fluorescence signal was the most intensively observed in the cellular uptake process, although some green and red fluorescence was also observed. Since the cores of Fe3O4 could be completely or partly eliminated in a controllable way, it can be used as a magnetic resonance imaging agent. In addition, their easily modifiable hydrophilic surfaces for multi-functionality and hydrophobic voids covered by oxidized graphite make them promising candidates for applications in cellular photo-imaging and targeted drug delivery.

Photosensitizer and vancomycin-conjugated novel multifunctional magnetic particles as photoinactivation agents for selective killing of pathogenic bacteria.

Novel multifunctional magnetic particles (MMPs) conjugated with photosensitizer and vancomycin were fabricated by surface modification of Fe(3)O(4) particles. The capacities to target, capture and inactivate pathogenic bacteria and good biocompatibility suggest that the MMPs have great potentials as photodynamic inactivation agents for serious bacterial contamination.

Synthesis of highly magnetic graphite-encapsulated FeCo nanoparticles using a hydrothermal process.

The graphite encapsulation of metal alloy magnetic nanoparticles has attracted attention for biological applications because of the high magnetization of the encapsulated particles. However, most of the synthetic methods have limitations in terms of scalability and economics because of the demanding synthetic conditions and low yields. Here, we show that well controlled graphite-encapsulated FeCo core-shell nanoparticles can be synthesized by a hydrothermal method, simply by mixing Fe/Co with sucrose as a carbon source. Various Fe/Co metal ratios were used to determine the compositional dependence of the saturation magnetization and relaxivity coefficient. Transmission electron microscopy indicated that the particle sizes were 7 nm. In order to test the capability of graphite-encapsulated FeCo nanoparticles as magnetic resonance imaging (MRI) contrast agents, these nanoparticles were solubilized in water by the nonspecific physical adsorption of sodium dodecylbenzene sulfonate.