The present disclosure provides stimuli-responsive particles, methods of preparing stimuli-responsive particles, and methods of using the stimuli-response particles. Unlike conventional platforms, (e.g., polymers, liposomes, dendrimers) the particles of the present disclosure have precise size control of the particle diameter, high uniformity, high stability, high active agent uptake capacity, minimal premature active agent leakage, biocompatibility, and biodegradability. Additionally, the present disclosure provides magnetic resonance imaging (MRI) systems and methods of using the MRI systems in combination with the stimuli-responsive particles described herein.

The present disclosure provides stimuli-responsive particles, methods of preparing stimuli-responsive particles, and methods of using the stimuli-response particles. Unlike conventional platforms, (e.g., polymers, liposomes, dendrimers) the particles of the present disclosure have precise size control of the particle diameter, high uniformity, high stability, high active agent uptake capacity, minimal premature active agent leakage, biocompatibility, and biodegradability. Additionally, the present disclosure provides magnetic resonance imaging (MRI) systems and methods of using the MRI systems in combination with the stimuli-responsive particles described herein.

Biomimetic magnetic nanoparticles comprising MamC. The present invention provides superparamagnetic biomimetic nanoparticles comprising magnetite, which can be produced using a scalable process. In addition, these nanoparticles exhibit promising properties, since, if functionalized, they can be converted into drug carriers or contrast agents for obtaining clinical images. They can also be used in clinical setting to purge bone marrow, as molecule separators, and/or for environmental applications as biosensors. These nanoparticles, coupled to a drug, can be encapsulated in liposomes, thereby obtaining magnetoliposomes, which can be functionalized for use in the targeted delivery/release of drugs. In addition, mixtures of magnetoliposomes (functionalized or not with a targeting agent) and functionalized biomimetic magnetic nanoparticles or liposomes containing mixtures of functionalized BMNPs and MNPs can be used to combine different treatments, such as, for example, targeted delivery/release of drugs and hyperthermia.

A magnetic particle imaging system includes a field free region generator and an excited magnetic field generator. The field free region generator generates a field free line with a direction of linear extension of a field free region as a direction of extension. The excited magnetic field generator generates an excited magnetic field in the field free line generated by the field free region generator. The excited magnetic field generator includes a first excited magnetic field generation unit and a second excited magnetic field generation unit. The first excited magnetic field generation unit and the second excited magnetic field generation unit are spaced from each other in the direction of extension of the field free line.

The present invention relates to a magnetic resonance structure with a cavity or a reserved space that provides contrast and the additional ability to frequency-shift the spectral signature of the NMR-susceptible nuclei such as water protons by a discrete and controllable characteristic frequency shift that is unique to each MRS design. The invention also relates to nearly uniform solid magnetic resonance T.sub.2* contrast agents that have a significantly higher magnetic moment compared to similarly-sized existing MRI contrast agents.

A magnet arrangement for generating a selection magnetic field with a gradient and a field-free region in a sample volume includes: a Maxwell magnet system with two ring magnets, which are arranged in coaxial fashion and at a distance from one another on a common Z-axis extending through the sample volume, a focus field coil arrangement with at least one focus field coil pair for displacing the field-free region within the sample volume, and a drive coil for generating an MPI drive field. The magnet arrangement comprises a quadrupole magnet system with at least one quadrupole ring for generating a quadrupole magnetic field, the quadrupole magnet system being arranged coaxially with respect to the Maxwell magnet system. Using the magnet arrangement according to the invention, it is possible to switch between a selection magnet field with a field-free point and a field-free line without undesirably increasing the field gradient.

A method for electronic calibration of a magnetic particle imaging system is provided by proposing a coded calibration scene that contains multiple nanoparticle samples distributed randomly or pseudo-randomly inside a volume of the coded calibration scene where nanoparticle positions are changed virtually multiple times to create different calibration scenes. Virtual effect is created with current carrying electromagnets surrounding the nanoparticle samples. The method comprises: placing a plurality of nanoparticle samples inside a calibration scene; surrounding the plurality of nanoparticle samples with one or more electromagnets; applying a current to the one or more electromagnets to cause a magnetic field offset at a desired amplitude to virtually move the plurality of nanoparticle samples to a desired position; generating a system matrix with compressed sensing methods by using measurements taken for different current excitations of the one or more electromagnets, wherein the plurality of nanoparticles samples are virtually in different positions.

A method for electronic calibration of a magnetic particle imaging system is provided by proposing a coded calibration scene that contains multiple nanoparticle samples distributed randomly or pseudo-randomly inside a volume of the coded calibration scene where nanoparticle positions are changed virtually multiple times to create different calibration scenes. Virtual effect is created with current carrying electromagnets surrounding the nanoparticle samples. The method comprises: placing a plurality of nanoparticle samples inside a calibration scene; surrounding the plurality of nanoparticle samples with one or more electromagnets; applying a current to the one or more electromagnets to cause a magnetic field offset at a desired amplitude to virtually move the plurality of nanoparticle samples to a desired position; generating a system matrix with compressed sensing methods by using measurements taken for different current excitations of the one or more electromagnets, wherein the plurality of nanoparticles samples are virtually in different positions.

A pulsed magnetic particle imaging system includes a magnetic field generating system that includes at least one magnet, the magnetic field generating system providing a spatially structured magnetic field within an observation region of the magnetic particle imaging system such that the spatially structured magnetic field will have a field-free region (FFR) for an object under observation having a magnetic nanoparticle tracer distribution therein. The pulsed magnetic particle imaging system also includes a pulsed excitation system arranged proximate the observation region, the pulsed excitation system includes an electromagnet and a pulse sequence generator electrically connected to the electromagnet to provide an excitation waveform to the electromagnet, wherein the electromagnet when provided with the excitation waveform generates an excitation magnetic field within the observation region to induce an excitation signal therefrom by at least one of shifting a location or condition of the FFR. The pulsed magnetic particle imaging system further includes a detection system arranged proximate the observation region, the detection system being configured to detect the excitation signal to provide a detection signal. The excitation waveform includes a transient portion and a substantially constant portion.

A system for monitoring an approach to a target includes a luminal device including a distal portion, a sensor coupled to the distal portion of the luminal device, and a surgical instrument including one or more indicators having a detectable property located along at least a portion of the surgical instrument. The luminal device is configured to be inserted into a patient, and the distal portion of the luminal device is configured to be guided proximate a target. The sensor is configured to sense the detectable property of the one or more indicators. The surgical instrument is configured to be guided through the luminal device.