摘要:
In magnetic resonance imaging (MRI) based on chemical exchange-dependent saturation transfer (CEST), a novel carrier for CEST contrast agents is provided. The carrier is non-spherical and comprises a semipermeable shell, wherein the shell comprises a paramagnetic compound. The shell encloses a cavitycomprising an MR analyte, wherein the semipermeable shell allows diffusion of the MR analyte. The CEST effect is based on the 5 bulk magnetic susceptibility effect caused by the anisotropy of the carrier. This leads to a versatile carrier that does not require interaction of the analyte with a paramgnetic chemical shift reagent.
摘要:
The invention relates to a method of MR imaging of at least a portion of a body of a patient placed in an examination volume of an MR device. The object of the invention is to improve CEST contrast enhanced imaging. The method of the invention comprises the following steps: a) saturation of nuclear magnetization of exchangeable protons of a CEST contrast agent administered to the patient by subjecting the portion of the body to at least one frequency-selective saturation RF pulse matched to the MR frequency of exchangeable protons of the CEST contrast agent, wherein the saturation period, i.e. the duration of the frequency-selective saturation RF pulse, is shorter than the time required for saturation to build up a full CEST contrast enhancement effect when starting from zero saturation; b) generating at least one MR signal of water protons of the body by subjecting the portion of the body to an MR imaging sequence comprising at least one RF pulse and switched magnetic field gradients; c) acquiring sampling the at least one MR signal from the body; d) repeating steps a) to c) a number of times under variation of parameters of the MR imaging sequence, wherein MR signals are acquired and sampled during a saturation build-up period, i.e. before a steady state of the CEST effect is achieved; e) reconstructing a proton-density weighted, CEST contrast-enhanced MR image from the acquired and sampled MR signals.
摘要:
Described are Chemical Exchange-dependent Saturation Transfer (CEST) contrast agents for Magnetic Resonance Imaging (MRI) comprising a polymersome provided with a paramagnetic agent. The polymersome preferably comprises a polymeric shell enclosing a cavity, wherein the cavity comprises a pool of proton analytes, and wherein the shell allows diffusion of the proton analytes. The polymersome-based CEST MRI contrast agents are suitable as drug carriers useful in MRI-guided drug release.
摘要:
Described are drug carriers useful in magnetic resonance imaging (MRI)-guided drug release comprising a shell capable of releasing an enclosed biologically active agent as a result of a local stimulus, e.g. energy input, such as heat, wherein the shell encloses a 19F MR contrast agent. Preferably, the carrier also acts as a contrast enhancement agent for MRI based on the principle of Chemical Exchange-dependent Saturation Transfer (CEST). To this end the shell encloses a cavity that comprises a paramagnetic chemical shift reagent, a pool of proton analytes, and the 19F contrast agent, and wherein the shell allows diffusion of the proton analytes.
摘要:
Described are drug carriers useful in magnetic resonance imaging (MRI)-guided drug release comprising a shell capable of releasing an enclosed biologically active agent as a result of a local stimulus, e.g. energy input, such as heat, wherein the shell encloses a 19F MR contrast agent. Preferably, the carrier also acts as a contrast enhancement agent for MRI based on the principle of Chemical Exchange-dependent Saturation Transfer (CEST). To this end the shell encloses a cavity that comprises a paramagnetic chemical shift reagent, a pool of proton analytes, and the 19F contrast agent, and wherein the shell allows diffusion of the proton analytes.
摘要:
The present invention relates to a composition comprising a shell structure forming a cavity, wherein said shell structure comprises a drug and wherein said composition is associated with at least one contrast agent; wherein said shell structure is capable of releasing its contents into the exterior upon the application of an external stimulus and wherein said contrast agent comprises magnetic particles which are capable of being detected by Magnetic Particle Imaging (MPI), wherein at least more than 5% (w/w) of the magnetic particles comprised in said contrast agent have a magnetic moment of at least −18 m 2 A, 10 wherein said magnetic particles are preferably composed of Fe, Co, Ni, Zn or Mn or alloys thereof or oxides of any of these. The present invention further relates to the use of such a composition or a composition comprising a shell structure forming a cavity, wherein said shell structure comprises a drug and wherein said composition is associated with at least one contrast agent, wherein said contrast agent is capable of being detected by MPI and wherein said shell structure is capable of releasing its contents into the exterior upon the application of an external stimulus as a carrier for a controlled delivery of a drug, as well as to a method of data acquisition for the control of a drug delivery process comprising the detection or localization via MPI of such compositions. In a further aspect the present invention relates to such compositions for treating a pathological condition, wherein the treatment comprises the release of the drug by the application of a stimulus.
摘要:
Disclosed are lipidomimetic compounds of formula I (I) wherein: G represents a group satisfying formula II: HO—CH2—{CH(OH)—CH2-0}m-CH2—{C(=0)-0-CH2})q— formula II each n independently is an integer from 1-30; m is an integer from 1-10; q is 0 or 1. These compounds can be added to the lipid bilayer of thermosensitive liposomes, for the purpose of aiding in the prevention of leakage of the liposomes' contents at 37° C., and retarding clearance from circulation.
摘要:
A process for production of a polyolefin-based composite material of high rigidity, containing a polyolefin and a layered clay, involves impregnating a layered, swellable clay which is interstratified with a tetraalkyl cation, with at least one polymerizable monomer and then mixing this impregnated clay with a polyolefin and a peroxide, at a temperature above the melting point of the polyolefin. A polyolefin-based composite material containing 98-50 wt. % of a polyolefin, 1-50 wt. % of another homo- or copolymer and 1-50 wt. % of a layered clay, wherein the ratio between the modulus of elasticity of the material and that of the initial polyolefin, at a temperature which is 30° C. below the melting temperature of the polyolefin, is higher than or equal to 1 has high rigidity.
摘要:
Described are amphiphilic polymers that are provided with chelating moieties. The amphiphilic polymers are block copolymers comprising a hydrophilic block and a hydrophobic block, with the chelating moieties linked to the end-group of the hydrophilic block. The disclosed polymers are capable of self-assembly into structures such as micelles and polymersomes. With suitable metals present in the form of coordination complexes with 5 the chelating moieties, the chelating amphiphilic polymers of the invention are suitable for use in various imaging techniques requiring metal labeling, such as MRI (T 1/T 2 weighted contrast agents or CEST contrast agents) SPECT, PET or Spectral CT.
摘要翻译:描述的是具有螯合部分的两亲性聚合物。 两亲聚合物是包含亲水嵌段和疏水嵌段的嵌段共聚物,螯合部分连接到亲水嵌段的端基。 所公开的聚合物能够自组装成结构如胶束和聚合物囊泡。 使用与5个螯合部分配位络合物形式的合适金属,本发明的螯合两亲性聚合物适用于需要金属标记的各种成像技术,例如MRI(T 1 / T 2加权造影剂或CEST对比度 药剂)SPECT,PET或光谱CT。
摘要:
Described are amphiphilic polymers that are provided with chelating moieties. The amphiphilic polymers are block copolymers comprising a hydrophilic block and a hydrophobic block, with the chelating moieties linked to the end-group of the hydrophilic block. The disclosed polymers are capable of self-assembly into structures such as micelles and polymersomes. With suitable metals present in the form of coordination complexes with 5 the chelating moieties, the chelating amphiphilic polymers of the invention are suitable for use in various imaging techniques requiring metal labeling, such as MRI (T 1/T 2 weighted contrast agents or CEST contrast agents) SPECT, PET or Spectral CT.
摘要翻译:描述的是具有螯合部分的两亲性聚合物。 两亲聚合物是包含亲水嵌段和疏水嵌段的嵌段共聚物,螯合部分连接到亲水嵌段的端基。 所公开的聚合物能够自组装成结构如胶束和聚合物囊泡。 使用与5个螯合部分配位络合物形式的合适金属,本发明的螯合两亲性聚合物适用于需要金属标记的各种成像技术,例如MRI(T 1 / T 2加权造影剂或CEST对比度 药剂)SPECT,PET或光谱CT。