Melanoma incidence is growing worldwide.Although recent advances in imaging,there is not still available a specific melanoma agent that can be used for melanoma staging.Archaeosomes may be defined as liposomes compose...Melanoma incidence is growing worldwide.Although recent advances in imaging,there is not still available a specific melanoma agent that can be used for melanoma staging.Archaeosomes may be defined as liposomes composed of one or more polar lipids extracted from the Archaea domain(Archaebacterium).As liposomes have been used as vehicles for drugs and isotopes,the aim of this work is to evaluate radiolabelled 99mTc-archaeosomes as a potential melanoma imaging agent.and evaluate its potential role as a melanoma imaging agent.Archaeosomes were prepared by handshaken method and were radiolabeled with 99mTc;radiolabelling efficiency and purity were evaluated through different chromatographic systems.In vitro stability of 99mTc-diethylene-triamine-pentaacetate(DTPA)-archaeosomes was performed through L-cysteine challenge.Archaeosome size distribution was determined by laser light scattering,having nanometer size between 90 and 120 nm.Radiolabelling efficiency was>90%;99mTc-DTPAarchaeosomes presented a radiochemical purity superior to 80%evaluated 24 h post-radiolabelling.For the highest concentration of L-cysteine(30 mM)and 1 h incubation,radiochemical purity was 92.90%,6.41%was bound to cysteine,and 0.69%remained as 99mTcO4-.Biodistribution and scintigraphic imaging studies in healthy C57 black mice showed high liver,spleen uptake,and renal elimination.Melanoma bearing mice had similar biodistribution as healthy mice but increased melanoma uptake,with T/M ratio of 46±3.7.Our results show the feasibility of 99mTc radiolabelling archaeosomes and their potential role as a melanoma imaging agent.展开更多
文摘Melanoma incidence is growing worldwide.Although recent advances in imaging,there is not still available a specific melanoma agent that can be used for melanoma staging.Archaeosomes may be defined as liposomes composed of one or more polar lipids extracted from the Archaea domain(Archaebacterium).As liposomes have been used as vehicles for drugs and isotopes,the aim of this work is to evaluate radiolabelled 99mTc-archaeosomes as a potential melanoma imaging agent.and evaluate its potential role as a melanoma imaging agent.Archaeosomes were prepared by handshaken method and were radiolabeled with 99mTc;radiolabelling efficiency and purity were evaluated through different chromatographic systems.In vitro stability of 99mTc-diethylene-triamine-pentaacetate(DTPA)-archaeosomes was performed through L-cysteine challenge.Archaeosome size distribution was determined by laser light scattering,having nanometer size between 90 and 120 nm.Radiolabelling efficiency was>90%;99mTc-DTPAarchaeosomes presented a radiochemical purity superior to 80%evaluated 24 h post-radiolabelling.For the highest concentration of L-cysteine(30 mM)and 1 h incubation,radiochemical purity was 92.90%,6.41%was bound to cysteine,and 0.69%remained as 99mTcO4-.Biodistribution and scintigraphic imaging studies in healthy C57 black mice showed high liver,spleen uptake,and renal elimination.Melanoma bearing mice had similar biodistribution as healthy mice but increased melanoma uptake,with T/M ratio of 46±3.7.Our results show the feasibility of 99mTc radiolabelling archaeosomes and their potential role as a melanoma imaging agent.
