| Summary: | 碩士 === 國防醫學院 === 藥學研究所 === 97 === In order to improve the transfect efficiency of non-viral vector,
cationic polymers were studied. Cationic polymer, Branched polyethylenimine
( B-PEI ), has been approved to be an efficient agent for gene
delivery. PEI is a highly positive-charged organic macromolecule whose
amino group condensed DNA and enhanced gene delivery into the
nucleus of mammalian cells. Some reports demonstrated that the optimal
molecular weight of PEI is in the range from 20 to 30 kDa to delivery
DNA. But, Branched PEI also has cytotoxicity. Albumin is the most
abundant plasma protein. Because of its biodegradability and lack of
toxicity and immunogenicity, albumin is used as a drug carrier. Some
reports demonstrated that HSA enhances DNA transfection by combining
in lipoplexes.
To decrease the toxicity of PEI and increase protection of DNA, the
complex of DNA , human serum albumin ( HSA ) and polyethylenimine
( PEI ) was used in this study. pEGFP vector was used as reporter gene to
evaluated the transfection of formulations. HSA-PEI-DNA complexes
were obtained by adsorbed HSA on PEI-DNA complexes. The complex
was also crosslinked by using glutaraldehyde to extend the transfection of
DNA. Following two works were conducted in this study, including : (1)
To evaluate the physicochemical properties of formulation, such as zeta
potential, particle size distribution and surface morphology ; (2) To
evaluate the transfect efficiency and toxicity of formulations by using
HEK 293 cell model. The jetPEI-DNA complex had the maximal
transfection efficiency ( 33.19 % ) which was used as positive control ;
the naked pEGFP had the least transfection efficiency ( 0.13 % ) which
was used as negative control. In this study we found that HSA could
increase the transfect efficiency and decrease the toxicity by adsorbed on
the PEI-DNA complex. Three formulations, H5 ( 5 μg DNA ), H 7.5 ( 5
μg DNA ) and H5 ( 10 μg DNA ), showed higher than 20 % cell transfect
efficiency and 80 % of cell viability with a good developing value.
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