The present invention improves an existing contrast agent, especially, a T1 contrast agent, and adopts a strategy in which the T1 contrast material is partially coated on a support surface to which a hydrophilic functional group is exposed. The partial coating strategy adopted in the present invention improves both the stability and contrast performance of T1 contrast agent nanoparticles, and such a strategy leads to very interesting technical development.

Superparamagnetic nanoparticle-based analytical method comprising providing a sample having analytes in a sample matrix, providing a point of care chip having analytical regions, each of which is a stationary phase having at least one or more sections, labeling each of the analytes with a superparamagnetic nanoparticle and immobilizing the labeled analytes in the stationary phase, providing an analytical device having a means for exciting the superparamagnetic nanoparticles in vitro and a means for sensing, receiving, and transmitting response of the excited superparamagnetic nanoparticles, placing the chip in the analytical device and exciting the superparamagnetic nanoparticles in vitro, sensing, receiving, and transmitting the response of the superparamagnetic nanoparticles, and analyzing the response and determining characteristic of the analytes, wherein the response of the superparamagnetic nanoparticles comprises harmonics. The present invention also provides the hybrid point of care chip and analyzer to be used in the analytical method.

Disclosed is a multi-functional nanoparticle delivery system comprising a biodegradable core of poly(lactic-co-glycolic acid) (PLGA) or calcium phosphate (CaP), encapsulating a nicotinamide adenine dinucleotide (NAD.sup.+) precursor and a sirtuin activator. Surrounding the core is a liposomal or polymeric layer containing one or more senolytic agents, and an outer layer of magnetic iron oxide nanoparticles for targeted delivery, external manipulation, and imaging. In some embodiments, the nanoparticle surface is functionalized for conjugation with autologous mesenchymal stem cells to enhance homing and regenerative potential. The system is pH-responsive, releasing its payload in acidic microenvironments typical of senescent or diseased cells, while remaining stable at physiological pH. This integrated design supports NAD.sup.+ restoration, sirtuin activation, senescent cell clearance, and tissue regeneration. Applications include treatment of age-related diseases, regenerative medicine, cardiovascular and neurodegenerative disorders, and cosmetic skin rejuvenation.

The present invention improves an existing contrast agent, especially, a T1 contrast agent, and adopts a strategy in which the T1 contrast material is partially coated on a support surface to which a hydrophilic functional group is exposed. The partial coating strategy adopted in the present invention improves both the stability and contrast performance of T1 contrast agent nanoparticles, and such a strategy leads to very interesting technical development.