Protocol 
RAC Application 
Kenneth L. Brigham, M.D. 
Preliminary Studies 
Appended are 4 reprints and 2 manuscripts currently under review which present a large 
amount of the information from our laboratories which is relevant to this proposal. Some of 
those data will be summarized briefly here and additional data will be discussed in more detail. 
Liposome delivery of drugs to the lungs One of us (H. Schreier) has worked with 
liposomes as a drug delivery system for many years. That body of work demonstrates that 
liposomes can be delivered by aerosols of a size that reach the lower respiratory tract (PI) and 
that drugs can be effectively delivered to the lungs by this delivery technology (P2). Extensive 
studies of the safety of aerosol delivery of liposomes to the lungs of experimental animals and 
humans have shown no evidence of toxicity, even with repeated delivery of heavy liposome 
doses (P3,P2). Dr. Schreier’s work also demonstrates the ability to target liposomes by altering 
their surface characteristics, including targeting to respiratory epithelial cells by incorporation 
of the attachment and fusion proteins from respiratory syncytial virus into the liposome 
surface (PI). 
In vivo delivery of DNA using cationic liposomes Beginning in 1989, we have 
conducted a series of studies using cationic liposomes to deliver plasmids to the lungs. We have 
assessed safety and efficacy of this technology with the goal of clinical application. 
In mice, we showed that either intravenous or intra-tracheal injection of 
plasmid/cationic liposome complexes resulted in expression of a chloramphenicol 
acetyltransferase (CAT) gene in the lungs (P4). Table 1 summarizes data from those studies. 
With the particular DNA construct which we used, we found that CAT expression was limited 
to the lungs, was related to the dose of DNA delivered and was higher in the lungs when the 
DNA was given intra-tracheally than when given intravenously. We saw no gross evidence of 
toxicity of the procedure in those studies. 
TABLE I 
CAT Activity in Lungs, Liver and Kidneys 72 hrs Following 
DNA-Liposome Injection into Mice 
% chloramphenicol acetylation per h per protein x 10'^ 
Route 
Lunqs 
Liver 
Kidneys 
Intravenous 
30 pg DNA per mouse 
24,5 
0 
0 
15 pg DNA per mouse 
10.1 
0 
0 
Intratracheal 
30 pg DNA per mouse 
35.7 
0 
0 
Intraperitoneal 
30 pg DNA per mouse 
0 
0 
0 
[1781 
Recombinant DNA Research, Volume 19 
