Abstract
The aim of this work was the preparation of stable liposomal gene transfer vesicles
for the in vitro and in vivo gene transfer. It should be possible to use these vesicles
for clinical issues on humans. The requirements for such vesicles are: high efficiency,
stability and security for the user and the patient.
The work contained investigations to the production, the biophysical characteristics,
that in vitro gene transfer efficiency as well as for stability and shelf-life of the gene
transfer vesicles.
Our results show that the gene transfer efficiency is in uenced by the following
factors: the constituents of the gene transfer vesicles, the production of the vesicles,
the ow of the transfection, the cell type and their culture conditions.
Concerning the vesicle constituents it was stated that for high
in vitro transfection rates lipids with a spermin headgroup are
particularly suitable. Out such lipids manufactured liposomal gene
transfer vesicles are however only briefly active and for a longer
storage not suitably.
On the other hand from monocationic lipids (DAC-Chol)
manufactured liposomes were suitable for the preparation of long term
stable gene transfer complexes. The efficiency and shelf-life of
these vesicles could be still increased by the addition of
protaminsulfate. An even more increased stability and the possibility
of freezing the preformulated gene transfer complexes was enabled by
the addition of saccharose. Saccharose lowered however the short time
activity of the gene transfer vesicles to a third of the activity of
gene transfer vesicles, which had been manufactured without sugar
addition. However the reduced short time activity could become
balanced by an increased dosage of the gene transfer complexes. The
investigations show that the use of lipid/protaminsulfate/DNA
complexes, which were manufactured in a saccharose containing
solution ensures an effective gene transfer in vitro and a promising
beginning for in vivo investigations as well as possible clinical
applications is. | 
