Magnetic nanoparticles based on iron oxides (MNPs-Fe) with magnetite or maghemite phases have been widely employed in bio-applications. Thus, they have been used as contrast agents in magnetic resonance imaging (MRI) and oncological treatments through different therapies. Besides, due to the vast health problem of multidrug-resistant bacterial infections, several studies have proposed MNPs-Fe as photothermal agents (PTAs) within antibacterial photothermal therapy (PTT). This work presents a quick and easy green synthesis (GS) to obtain MNPs-Fe using orange peel extract from orange waste from local commerce, which presents an environmentally friendly approach compared to traditional methods such as coprecipitation. The GS can be irradiated with microwaves to reduce the synthesis time drastically. We evaluated the weight yield of the GS and the physical-chemical and magnetic features of the synthesized MNPs-Fe. Besides their cytotoxicity in animal cell line ATCC RAW 264.7, their antibacterial activity against Staphylococcus Aureus (S. Aureus) and Escherichia Coli (E. Coli) was assessed. We found that the MNPs-Fe synthesized using the GS, with 50% v/v of NH4OH and 50% v/v of orange peel extract (50GS-MNPs-Fe) had an excellent weight yield, negligible cytotoxicity for concentrations of MNPs-Fe below 250 µg·mL-1 in 24 hours, and 8 days. In the MNPs-Fe surface, we identified a coating of organic molecules (~ 25 nm) such as terpenes, aldehydes, etc. MNPs-Fe inhibited S. Aureus and 2.54 log10 (CFU) of E. Coli under red LED light irradiation (630 nm, 65.5 mW·cm-2, 30 min). Likewise, they exhibited a superparamagnetic (SPM) behavior for temperatures above 60 K, with a size of 49.3±9.6 nm and saturation magnetization (Ms) of 72.83 and 44.16 emu·g-1 at 60 and 300 K, respectively. Therefore, 50GS-MNPs-Fe are excellent candidates as broad-spectrum PTAs in antibacterial PTT, magnetic hyperthermia (MH), or MRI.

Sentinel lymph node dissection (sLND) using a magnetometer and superparamagnetic iron oxide nanoparticles (SPIONs) as a tracer was successfully applied in prostate cancer (PCa). Radioisotope-guided sLND combined with extended pelvic LND (ePLND) achieved better node removal, increasing the number of affected nodes or the detection of sentinel lymph nodes outside the established ePLND template. We determined the diagnostic value of additional magnetometer-guided sLND after intraprostatic SPION-injection in high-risk PCa. This retrospective study included 104 high-risk PCa patients (PSA >20 ng/ml and/or Gleason score ≥8 and/or cT2c) from a prospective cohort who underwent radical prostatectomy with magnetometer-guided sLND and ePLND. The diagnostic accuracy of sLND was assessed using ePLND as a reference standard. Lymph node metastases were found in 61 of 104 patients (58.7%). sLND had a 100% diagnostic rate, 96.6% sensitivity, 95.6% specificity, 96.6% positive predictive value, 95.6% negative predictive value, 3.4% false negative rate, and 4.4% false positive rate (detecting lymph node metastases outside the ePLND template). These findings demonstrate the high sensitivity and additional diagnostic value of magnetometer-guided sLND, exceeding that of ePLND through the individualized extension of PLND or the detection of sentinel lymph nodes / lymph node metastases outside the established node template in high-risk PCa.

Targeted radioisotope-guided sentinel lymph node dissection (sLND) has shown high diagnostic accuracy in prostate cancer (PCa). To overcome the downsides of the radioactive tracers, magnetometer-guided sLND using superparamagnetic iron oxide nanoparticles (SPIONs) was successfully applied in PCa. This prospective study (SentiMag Pro II, DRKS00007671) determined the diagnostic accuracy of magnetometer-guided sLND in intermediate- and high-risk PCa. Fifty intermediate- or high-risk PCa patients (PSA≥10 ng/ml and/or Gleason score ≥7; median PSA 10.8 ng/ml, IQR 7.4–19.2 ng/ml) were enrolled. After intraprostatic SPIONs injection a day earlier, patients underwent magnetometer-guided sLND and eLND, followed by radical prostatectomy. SLNs were detected in vivo and in ex vivo samples. Diagnostic accuracy of sLND was assessed using eLND as the reference. SLNs were detected in all patients (detection rate 100%), with 447 SLNs (median 9, IQR 6–12) being identified and 966 LNs (median 18, IQR 15-23) being removed. Thirty-six percent (18/50) of patients had LN metastases (median 2, IQR 1–3). Magnetometer-guided sLND had 100% sensitivity, 97.0% specificity, 94.4% positive predictive value, 100% negative predictive value, 0.0% false negative rate, and 3.0% additional diagnostic value (LN metastases only in SLNs outside the eLND template). In vivo, one positive SLN/LN-positive patient was missed, resulting in a sensitivity of 94.4%. In conclusion, this new magnetic sentinel procedure has high accuracy for nodal staging in intermediate- and high-risk PCa. The reliability of intraoperative SLN detection using this magnetometer system requires verification in further multicentric studies.

Abstract: (1) Background: Sentinel lymph node biopsy assumes importance in the search for metastases, especially in patients with malignant breast disease. Our study approaches the new techniques to prevent complications such as possible postoperative seroma formation, pain or hypoesthesia of the axillary cord and medial arm surface, as well as motor deficits in a preventive manner to avoid disabling outcomes and presents initial data from its experience with the sentinel lymph node biopsy technique. (2) Methods: There are mainly two radioactive tracer detection techniques and a new technique using a radiotracer called Sentimag-magtrace. The positive lymph node is located and removed to perform histologic analysis. In our study, we evaluate 100 patients who underwent breast cancer surgery (3) Results: our experience allowed us to calculate the identification rate with the different methods of sentinel lymph nodes by radioactive tracer 88.9 % vs magnetic tracer technology (Sentimag) 89.5%. (4) Conclusions: Thus, this technique avoids radiation exposure for both patients and health care providers, as well as reducing costs and time.

The aim of this study was to develop a novel nanostructured lipid carriers (NLCs) with hepatocytes targeting as carriers for the magnetic resonance imaging (MRI) contrast agent (i.e., magnetic nanostructured lipid carriers, MNLCs), and to evaluate the targeting ability of the MNLCs with T2-weighted MRI both in vitro and in vivo. Here, the galactose-octadecylamine (Gal-ODA) conjugates were synthesized by chemical coupling reaction between lactose acid (LA) and octadecylamine (ODA). Then the superparamagnetic iron oxide (SPIO) loaded nanostructured lipid carrier (conjugated by Gal-ODA, Gal-NLC-SPIO) was prepared by emulsification-ultrasonic method using monoglyceride as lipid materials. The Gal-NLC-SPIO with a diameter of about 50 nm could specifically internalize into LO2 (human hepatic cell line) cells. In vitro MRI results also proved the specific targeting ability of Gal-NLC-SPIO to LO2 cells. The in vivo MR imaging experiments using an orthotopic intrahepatic xenograft tumor model further validated the hepatocytes targeted effect of Gal-NLC-SPIO. The results of this study suggested that Gal-NLC-SPIO can be used as a contrast agent to aid in the diagnosis of hepatic diseases.

The aim of this work is a comprehensive study of the effect of variable atomic composition and structural-phase state of (CoFeZr)x(MgF2)100-x nanocomposites (NCs) on their nonlinear electronic and magnetic/magneto-optical properties. Micrometer-thick nanocomposites layers on the glass substrates were obtained by ion-beam sputtering of a composite target in the argon atmosphere in a wide range of compositions x=9-51at.% The value of the resistive percolation threshold xper=34 at.%, determined from the concentration dependences of the electrical resistance of NCs, coincides with the beginning of nucleation of metallic nanocrystals CoFeZr in MgF2 dielectric matrix. The absolute value of maximum magnetoresistance of NCs is 2.4 % in a magnetic field of 5.5 kOe at x=25 at.%, up to the percolation threshold. Two maxima appear in the concentration dependences of magneto-optical transversal Kerr effect, one of which at x = 34 at.% corresponds to the formation of CoFeZr alloy nanocrystals of a hexagonal structure, and the second one at x=45 at.% corresponds to the phase transition of nanocrystals from a hexagonal to a cubic body-centered structure. The magnetic percolation threshold in (CoFeZr)x(MgF2)100-x system at xfm=34 at.% with the appearance of a hysteresis loop and a coercive force of Hc≈ 8 Oe, coincides with the resistive percolation threshold xper=34 at.%. Concentration dependence of the coercive force showed that at low contents of metallic alloy x<30 at.% NCs are superparamagnetic (Hc=0). With an increase of the alloy content, in the region of magnetic and resistive percolation thresholds NCs exhibit a magnetically soft ferromagnetic character and do not change it far beyond the percolation threshold with the maximum value of the coercive force Hc< 30 Oe. Decrease in magnetic order and soft ferromagnetic are influenced by the diamagnetic phase FeF2 that we discovered at the interface of magnetic nanocrystals CoFeZr with a dielectric matrix MgF2 by the Mössbauer spectroscopy.