Abstract: Macromolecular contrast agents for magnetic resonance imaging are described. Biomolecules and their modified derivatives form stable complexes with paramagnetic ions thus increasing the molecular relaxivity of carriers. The synthesis of biomolecular based nanodevices for targeted delivery of MRI contrast agents are described. Nanoparticles (NP) have been constructed by self-assembling of chitosan (CHIT) as polycation and poly-gamma glutamic acids (PGA) as polyanion. NP's are capable of Gd-ion uptake forming a particle with suitable molecular relaxivity. Folic acid (FA) is linked to the NP's to produce NP-FA bioconjugates that can be used for targeted in vitro delivery to a human cancer cell line.

Abstract: Macromolecular contrast agents for magnetic resonance imaging are described. Biomolecules and their modified derivatives form stable complexes with paramagnetic ions thus increasing the molecular relaxivity of carriers. The synthesis of biomolecular based nanodevices for targeted delivery of MRI contrast agents are described. Nanoparticles (NP) have been constructed by self-assembling of chitosan (CHIT) as polycation and poly-gamma glutamic acids (PGA) as polyanion. NP's are capable of Gd-ion uptake forming a particle with suitable molecular relaxivity. Folic acid (FA) is linked to the NP's to produce NP-FA bioconjugates that can be used for targeted in vitro delivery to a human cancer cell line.

Abstract: The present invention relates to biocompatible and biodegradable stimuli-sensitive polymeric nanoparticles, which were formed by ion-ion interaction in aqueous media. Synthetic and biological macromolecules with ionizable functional groups are capable of forming nanoparticles whose size and surface properties are sensitive to environmental influences such as pH, temperature and salt concentration. Nanodevices are designed for therapeutic applications as drug and nucleic acid carriers, and/or for MRI diagnosis as contrast agents. These nanodevices are designed for therapeutic applications as targeted drug carriers. Additionally, they can be used as contrast agents for MRI diagnosis. These nanosystems are also potential carriers for delivery of active ingredients as DNA, RNA, short interfering RNA (siRNA), antisense oligonucleotides (AS-ON), and triple helix forming oligonucleotides (TFO) etc. for pharmaceutical applications. Their adjustable size offers yet another advantage.