This laboratory has previously described the aggregation of intravenously administered lipid-coated microbubbles (LCM) around tumors and areas of injury. 7β-Hydroxycholesterol has been used to inhibit astrocytic proliferation in nervous system injury models. The compound has been given by direct infusion, by epidural catheter, or in liposomes (delivered stereotactically to the injury site). In this article, we report the use of LCM to deliver 7β-hydroxycholesterol to a radiofrequency injury site in the rat cerebrum.METHODS:
First, the ability of LCM to target the thermal lesion in the rat brain was characterized using a lipid-soluble fluorescent dye 3,3-dioctadecyloxacarbocyanine perchlorate. Then, the effectiveness of this delivery system in suppression of glial proliferation was measured by glial fibrillary acidic protein immunoreactivity.RESULTS:
Glial fibrillary acidic protein immunoreactivity was significantly reduced when 7β-hydroxycholesterol was administered via LCM but not alone, suggesting that astrocytic proliferation would correspondingly be diminished.CONCLUSION:
LCM were assessed as a delivery vehicle for 7β-hydroxycholesterol in a rat brain radiofrequency lesion and found to be efficient in reducing astrogliosis, as measured by glial fibrillary acidic protein immunoreactivity.