TY - JOUR
T1 - Effect of serum on transfection by polyethylenimine/virus-like particle hybrid gene delivery vectors
AU - Drake, David M.
AU - Keswani, Rahul K.
AU - Pack, Daniel W.
N1 - Funding Information:
This work was supported by the National Science Foundation (BES 06-02636) and the American Cancer Society (RSG-05-019-01-CDD). Flow cytometry was performed at the Flow Cytometry Facility of the Roy J. Carver Biotechnology Center at the University of Illinois, and confocal microscopy was performed at the Center for Microscopic Imaging at the University of Illinois College of Veterinary Medicine.
PY - 2010/11
Y1 - 2010/11
N2 - Purpose: Murine leukemia virus-like particles (M-VLP) complexed with polymers to promote cellular uptake and endosomal escape represent a new class of effective gene delivery vectors. Building upon recent studies of viral-synthetic hybrid vectors, we report the effects of serum on the formation, activity and stability of PEI/M-VLP complexes. Methods: M-VLP were produced by cells grown in serum-supplemented media (M-VLP-S), serum-free media (M-VLP-SF) or serum-free Opti-MEM® I (M-VLP-OM). PEI/M-VLP stoichiometry was varied to investigate complex formation and optimal transfection conditions. The effects of prolonged storage, freeze-thaw cycles, and ultracentrifugation of M-VLP on the stability of vector transduction efficiency were also observed. Results: M-VLP-S required more PEI to form infective complexes than M-VLP-SF and M-VLP-OM. The stoichiometry of PEI/M-VLP-S was dependent on total PEI concentration (7-8 μg/100 μL M-VLP supernatant), while optimal infectivity of PEI/M-VLP-SF and PEI/M-VLP-OM depended on PEI/M-VLP ratios (12-17 μg and 10-14 μg PEI/109 M-VLP, respectively). PEI/M-VLP-SF and PEI/M-VLP-OM complexes were significantly more efficient than PEI/M-VLP-S. Stability of the hybrid vectors was not significantly affected by serum. Conclusions: PEI/M-VLP complexes exhibiting increased efficiency were constructed by producing M-VLP in serum-free media. M-VLP could be stored by freezing or refrigeration and concentrated by ultracentrifugation without unacceptable loss of infectivity.
AB - Purpose: Murine leukemia virus-like particles (M-VLP) complexed with polymers to promote cellular uptake and endosomal escape represent a new class of effective gene delivery vectors. Building upon recent studies of viral-synthetic hybrid vectors, we report the effects of serum on the formation, activity and stability of PEI/M-VLP complexes. Methods: M-VLP were produced by cells grown in serum-supplemented media (M-VLP-S), serum-free media (M-VLP-SF) or serum-free Opti-MEM® I (M-VLP-OM). PEI/M-VLP stoichiometry was varied to investigate complex formation and optimal transfection conditions. The effects of prolonged storage, freeze-thaw cycles, and ultracentrifugation of M-VLP on the stability of vector transduction efficiency were also observed. Results: M-VLP-S required more PEI to form infective complexes than M-VLP-SF and M-VLP-OM. The stoichiometry of PEI/M-VLP-S was dependent on total PEI concentration (7-8 μg/100 μL M-VLP supernatant), while optimal infectivity of PEI/M-VLP-SF and PEI/M-VLP-OM depended on PEI/M-VLP ratios (12-17 μg and 10-14 μg PEI/109 M-VLP, respectively). PEI/M-VLP-SF and PEI/M-VLP-OM complexes were significantly more efficient than PEI/M-VLP-S. Stability of the hybrid vectors was not significantly affected by serum. Conclusions: PEI/M-VLP complexes exhibiting increased efficiency were constructed by producing M-VLP in serum-free media. M-VLP could be stored by freezing or refrigeration and concentrated by ultracentrifugation without unacceptable loss of infectivity.
KW - gene delivery
KW - hybrid vectors
KW - murine leukemia virus
KW - polyethylenimine
KW - virus-like particles
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U2 - 10.1007/s11095-010-0238-z
DO - 10.1007/s11095-010-0238-z
M3 - Article
C2 - 20730559
AN - SCOPUS:78549264038
SN - 0724-8741
VL - 27
SP - 2457
EP - 2465
JO - Pharmaceutical Research
JF - Pharmaceutical Research
IS - 11
ER -