Novel phospholipid-modified-polyethylenimine (PLPEI)-based-nanocarriers for siRNA delivery
Permanent URL:
http://hdl.handle.net/2047/D20196782
Amiji, Mansoor (Committee member)
Clark, Heather (Committee member)
Schatz, Robert (Committee member)
Tracy, Mark (Committee member)
The first aim of this project was to evaluate if these MNPs could be utilized for siRNA delivery and gene silencing in vitro. The possibilities of two other structurally different PLPEI-based nanocarriers for their siRNA delivery and gene silencing potential were explored, followed by studies to elucidate their mechanism of action and thus, explain why some PLPEI nanocarriers performed better in vitro with respect to siRNA delivery and silencing over the other PLPEI-based nanocarriers. Dioleoyl phosphoethanolamine-PEI (DOPE-PEI) was found to be best PLPEI nanocarrier in vitro for intracellular siRNA and downregulation of a model protein (Green fluorescent protein or GFP). Further, DOPE-PEI was chosen for downregulating the MDR1 gene that encodes for P-glycoprotein (P-gp) in human breast cancer cells in vitro. The aim was to exhibit that the combination therapy of siRNA and drug can overcome multidrug resistance (MDR) in cancer therapy by downregulating P-gp.
In vivo studies with the PLPEI nanocarriers have been branched into two sections. First, the biodistribution profile of the PLPEI-based nanocarriers was studied in an in vivo subcutaneous (s.c.) murine tumor model closely mimicking human breast cancer tumor xenograft, in female Balb/c mice. With an aim to overcome MDR in vivo, therapeutic efficacy and P-gp downregulation studies were then performed in s.c. human breast cancer tumor xenograft model (MCF7/ADR) in nude, female mice using the combination treatment of siRNA and doxorubicin hydrochloride (dox).
Preliminary data has also been presented with transferrin conjugated micelles that have been formulated based on PLPEI, loaded with siRNA, with the aim of developing a targeted siRNA delivery system for prospective improved tumor targeting in vivo.
Specific Aims for the project
1. To formulate and characterize PLPEI based Micelle-like-Nanoparticles (MNPs) specifically, 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine-PEI (PAzPC-PEI or PC-PEI) - based MNPs for in vitro siRNA delivery and gene downregulation.
2. To develop and characterize phosphoethanolamine-modified PEI (PE-PEI)-based nanocarriers for siRNA delivery and compare their effectiveness with regards to intracellular delivery and gene silencing in vitro against PAzPC-PEI- based nanocarriers via studies to elucidate their mechanism of action.
3. To develop and characterize PE-PEI-based, siRNA loaded MNPs, targeting the MDR1 gene (siMDR1) and evaluate the efficacy of the combination therapy of siMDR1 loaded MNPs and doxorubicin in overcoming MDR in human breast cancer cells.
4. To evaluate the biodistribution of DOPE-PEI/siRNA-based nanocarriers and the role of PEGylation in the organ distribution profile and blood circulation time.
5. To evaluate the therapeutic efficacy and MDR1 gene downregulation capacity of the DOPE-PEI/siRNA and doxorubicin combination therapy.
6. To formulate DOPE-PEI based transferrin (Tf)-conjugated micelles for prospective utilization as targeted siRNA delivery system in vitro.
nanocarrier
PEI
polymer
siRNA
Nanoparticles -- Therapeutic use
Drug delivery systems
Small interfering RNA -- Therapeutic use
Polyethylene -- Therapeutic use
Polymers -- Therapeutic use
Micelles -- Therapeutic use
Breast -- Cancer -- Treatment
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