pH响应性掺锰非晶态碳酸钙纳米颗粒的制备及其在小鼠乳腺癌磁共振成像中的研究OA

Objective To prepare a pH-responsive Mn-doped amorphous calcium carbonate nanoparticle(Mn@ACC/PAA),and to assess its efficacy as MRI contrast agents through in vitro relaxivity and in vivo tumor-targeted imaging,along with comprehensive biosafety evaluation including cytotoxicity and blood compatibility.Methods The morphology of the nanomaterials was characterized using transmission electron microscopy.The hydrodynamic diameter was measured by dynamic light scattering.Additionally,the material properties were analyzed through a combination of spectroscopic techniques:ultraviolet-visible absorption spectroscopy was employed to examine light absorption characteristics,X-ray diffraction to identify crystal structures,Fourier-transform infrared spectroscopy to detect surface functional groups,and X-ray photoelectron spectroscopy to reveal elemental composition and chemical states.The MRI performance of the Mn@ACC/PAA was evaluated with 1.0T small animal MRI system;and its biosafety was assessed via Cell Counting Kit-8(CCK-8)assays and hemolysis tests.Results Spherical Mn@ACC/PAA nanoparticles(with a diameter of 16.29 nm)were prepared successfully,they exhibited good solution dispersibility and monodispersity.The particles released Mn2+under acidic conditions(pH 5.5),achieving high r1(18.07 mM-1·s-1)for enhanced T1-weighted contrast.The material showed low toxicity to mouse embryonic fibroblast cell line NHI/3T3 but concentration-dependent cytotoxicity to mouse mammary tumor cell line 4T1,with minimal hemolysis and good biocompatibility.Conclusion The pH-responsive amorphous calcium carbonate nanoparticles prepared via manganese doping not only enable efficient T1-weighted magnetic resonance imaging but also demonstrate excellent biocompatibility,which opens new avenues for their application in clinical fields such as tumor diagnosis.