[Study of TAT-PEG loaded magnetic liposomes crossing blood spinal cord barrier after spinal cord injury in rats].

OBJECTIVE

To evaluate the ability of a kind of novel magnetic liposomes modified with polyethylene glycol (PEG) and transactivating-transduction protein (TAT) to cross the blood spinal cord barrier (BSCB) so as to demonstrate whether or not they can accumulate at the lesions of injured spinal cord.

METHODS

The novel liposomes were made through reverse-phase evaporation method modified with polyethylene glycol (PEG) and transactivating-transduction protein (TAT) with an iron core. Thirty-six Wistar rats subject to spinal cord injury (SCI) at T10 were randomly divided into three groups (Groups I, II and III). The rats of Group III were injected with TAT-PEG loaded magnetic liposomes (4.55 mg/kg). The rats of GroupII received an injection of the equivalent PEG loaded magnetic liposomes while those of control group (GroupI) the equivalent normal saline. The accumulation of liposomes was observed by MRI (magnetic resonance imaging), Prussian blue staining, electron microscope and flame atomic absorption spectrophotometer.

RESULTS

This kind of TAT-PEG loaded magnetic liposomes could cross the BSCB and enter into the cells around the injured tissue. A low signal of T2WI on MRI could also be found in Group III. The results of flame atomic absorption spectrophotometer showed that the iron content accumulated around the lesion site in Group III was obviously higher than the other two groups (P < 0.05).

CONCLUSION

The TAT-PEG loaded magnetic liposomes may be employed as one kind of novel drug carrier to cross the BSCB and accumulate at tissue cells of spinal cord. It is likely to become a new therapy for SCI.