ABSTRACT
BACKGROUND:Transferrin (Tf) is one suitable ligand to be conjugated to drug delivery systems to achieve site-specific targeting and desired therapeutic effect, due to its specific binding to transferrin receptors (TfR), and high expression on the surface of tumor cells. Contrast agents are also modified with Tf to achieve specific tumor imaging. OBJECTIVE:To prepare Tf-labeled magnetoliposomes (MLs), and characterize their utility as TfR targeted MR specific contrast agent in vitro. METHODS:MLs and Tf-MLs were prepared by lipid film hydration method and covalent coupling method, respectively. Tf-MLs were characterized by their mean size, zeta potential, polyindex, r2 relaxivity, Tf-binding efficacy and cytotoxicity.In vitro MRI contrasting properties of the suspended nanoparticles incubated with HepG2 cells were determined. RESULTS AND CONCLUSION:The mean diameter, polydisperisity index, zeta potential and r2 relexivity of Tf-ML were 95.1 nm, 0.21,-1.25 mv and 94.62 mmol-1/s, respectively. The coupling efficiency was calculated and the values obtained were 59.4 μg Tf/μmol phospholipid corresponding to about 27 molecules of Tf-MLs. After a 2-hour incubation with rhodamine-labeled Tf-MLs, rhodamine fluorescence was detected intensively in the plasma membrane and the cytoplasm of the TfR-overexpressing HepG2 cells. In contrast, Tf-ML showed little binding in MCF-7 cells that had low TfR level. HepG2 cels incubated with Tf-ML showed much higher intracellualar iron density than incubated with non-targeted MLs.In vitro MR T2WI of cells demonstrated the centrifuge tube containing HepG2 cells incubated with Tf-MLs produced a lower visible signal intensity than that treated with non-targeted MLs. Tf-MLs showed their potentials such as high r2 relaxivity, specific binding ability characteristics. These results suggest the availability of Tf-MLs to serve as a targeted contrast agent.
ABSTRACT
<p><b>OBJECTIVE</b>To observe the impacts on pain matrix (PM) brain area in the patients of cervical spondylosis of neck type treated with acupuncture at single point and the multiple points.</p><p><b>METHODS</b>Forty-nine patients of cervical spondylosis of neck type were randomized into a single-point group (25 cases) and a multiple-point group (24 cases), and treated with acupuncture at Bailao (EX-HN 15) singly or Bailao (EX-HN 15) and Hegu (LI 4) in combination correspondingly. At the same time, 19 healthy people were selected as a control group. The resting state functional magnetic resonance imaging (fMRI) was conducted in each group before and after treatment. The changes in the regional homogeneity (ReHo) of brain area PM were analyzed in terms of the different therapeutic programs. The relevant analysis was on the scores of the Northwick Park neck pain questionnaire (NPQ) and short form 36 questionnaire (SF-36) for life quality.</p><p><b>RESULTS</b>Compared with the control group, ReHo value was increased in supplementary motor area (SMA) of PM in the patients, of cervical spondylosis of neck type. In the single-point group, after treatment, ReHo value was reduced in the bilateral medial superior frontal gyri of patients. In the multiple-point group, ReHo values were reduced in the left medial superior frontal gyrus and right SMA in PM area after treatment. In the single-point group, ReHo value in each brain area of PM was not significantly correlated with NPQ and SF-36 scores. In the multiple-point group, the changes of ReHo value in superior frontal gyrus were positively correlated with those of NPQ scores.</p><p><b>CONCLUSION</b>Considering the clinical efficacy of acupunctrue for cervical spondylosis of neck type, the overall result in the multiple-point group is better than that in the single-point group. It is deduced that the advantages of the therapeutic program in the multiple-point group is relevant with the cooperative integration of the stimulation at multiple points in cerebral analgesic center.</p>