ABSTRACT
To assess a novel cell manipulation technique of tissue engineering with respect to its ability to augment superparamagnetic iron oxide particles (SPIO) labeled mesenchymal stem cells (MSCs) density at a localized cartilage defect site in an in vitro phantom by applying magnetic force.Meanwhile,non-invasive imaging techniques were use to track SPIO-labeled MSCs by magnetic resonance imaging (MRI).Human bone marrow MSCs were cultured and labeled with SPIO.Fresh degenerated human osteochondral fragments were obtained during total knee arthroplasty and a cartilage defect was created at the center.Then,the osteochondral fragments were attached to the sidewalls of culture flasks filled with phosphate-buffered saline (PBS) to mimic the human joint cavity.The SPIO-labeled MSCs were injected into the culture flasks in the presence of a 0.57 Tesla (T) magnetic force.Before and 90 min after cell targeting,the specimens underwent T2-weighted turbo spin-echo (SET2WI) sequence of 3.0 T MRI.MRI results were compared with histological findings.Macroscopic observation showed that SPIO-labeled MSCs were steered to the target region of cartilage defect.MRI revealed significantchanges in signal intensity (P＜0.01).HE staining exibited that a great number of MSCs formed a three-dimensional (3D) cell "sheet" structure at the chondral defect site.It was concluded that 0.57 T magnetic force permits spatial delivery of magnetically labeled MSCs to the target region in vitro.High-field MRI can serve as an very sensitive non-invasive technique for the visualization of SPIO-labeled MSCs.
ABSTRACT
Objective To prepare the Target-directed probe(Hab18-SPIO) and to test its phisichemical characteristics. Methods The McAb Target-directed probe(Hab18-SPIO) was prepared through hepatocellular carcinoma(HCC) McAb(Hab18) conjugated toSPIO using chemical method,while negative McAb probe(SED-SPIO) was also prepared using the same method.These agents weretested by high-performance liquid chromatography(HPLC) and electron microscope. Results The results of HPLC and electronmicroscope proved that Hab18 was conjugated SPIO effectively.The diameter of particles was between 50 and 70 nm.The binding rate of Hab18 was 97.5%. Conclusion The probe targeted to membrane-associated antigen of HCC(Hab18g) has been successfully prepared,which has novel physiochemical property.It is of great value in specific MR diagnosis of early HCCs.