EXPERIMENTAL
SUMMARY: The selective over expression of ferritin receptor (Fr) in breast cancer cells provide a unique opportunity to deliver therapeutic agents to cancer cells via receptor mediated endocytosis mechanism. The present study is aimed at designing and development of doxorubicin bearing solid lipid nanoparticles coupled with ferritin for their selective and preferential presentation at tumour cells and thus assessing their targetability.
Akash Chaurasiya1, Mayank Singhal and Anil K. Chaurasiya2
1Faculty of Pharmacy, Jamia Hamdard, New Delhi, India2Pharmacy Department, S.N. Medical College, Agra, India
e-mail: [email protected]
Solid lipid nanoparticles have been widely investigated clinically for various purposes such as selective drug delivery and diagnostic agents [1-2]. Solid lipid nanoparticles encapsulated anticancer drugs reveal their potential for increased therapeutic efficacy and decreased nonspecific toxicities due to their ability to enhance the delivery of chemotherapeutic agents to tumors. The ferritin molecule is a hollow protein shell (outside diameter 12–13 nm, inside 7–8 nm), composed of 24 polypeptide chains and capable of storing up to 4500 Fe (III) atoms as an inorganic complex [3] Iron is vital element for the metabolism, viability and proliferation of normal and of cancer cells. In the work done by various researchers, ferritin has been identified as one of the successful targets commonly found on tumour cells of breast, liver, colon, etc, while cell types with normal phenotype express low or frequently undetectable levels of ferritin [4]. Researchers observed that ferritin level is increased in tumour cells or malignant cells which could be due to an increase in number of receptors responsible for uptake of ferritin (i.e. iron storage protein). The present study is aimed at designing and development of doxorubicin bearing solid lipid nanoparticles coupled with ferritin for their selective and preferential presentation at tumour cells and thus assessing their targetability.
[1] C. Schwarz, W. Mehnert, J.S. Lucks, R.H. Muller, J Control Rel., 1994, 30, pp. 83–96.[2] R.H. Muller, W. Mehnert, J.S. Lucks, C. Schwarz, A.Z. Muhlen, H. Weyhers, C. Freitas , D. Ruhl, Eur J Pharm Biopharm, 1995, 41, pp. 62–69.[3] G.C. Ford, P.M. Harrison, D.W. Rice, J.M.A. Smith, A. Treffry, J.L. White, J. and Yariv, Phil. Trans. R. Soc. Lond. B, 304, 1984, pp. 551-565.[4] S.B. Mark, J.N. Thomson, The EMBO J, 1983, 2, pp. 1599–603.
TEM Photomicrogra
ph of Optimized SLN-PEG-Fr
SEM Photomicrogra
ph of optimized
SLN-PEG-Fr
B
Size, PDI and Entrapment Efficiency of Optimized SLN
Formulations
INTRODUCTION
Surface Morphology
FLUORESCENCE MICROSCOPY
PBS (pH 7.4) containing 1%
tween-80
Cellular uptake studies Cellular uptake studies were conducted with SLNs formulation encapsulating calcein dye diluted in 1 ml of RPMI-1640 and added to monolayers of MDA-MB-468 breast cancer cells grown in 25 mm culture flask and incubating 2x105 cells for 0.5, 1, 2, 3 and 4 hours at 37º C.
Fr-conjugated SLNs
Solvent dilution method
Characterization of SLNs•Shape and morphology by transmission electron microscopy and Scanning electron microscopy
•Vesicle size and size distribution using Zetasizer 3000 (Malvern Inst. Ltd., UK).
•Entrapment of doxorubicin in SLNs formulation using minicolunm centrifugation technique.
•In vitro drug release from the formulations using dialysis membrane.
Tristearin, HSPC, cholesterol and Fr-PEG-
DSPE conjugate (40:40:20:1) dissolved in
ethanol at 40ºC
SLN Preparation
Formulation
code
Size (nm)
PDI EntrapmentEfficiency
(%)SLN-PEG 154.1±3.
540.08
247.34±2.45
SLN-PEG-Fr
189.2±2.46
0.094
59.25±1.86
RESULTS AND DISCUSSION
0
10
20
30
40
50
60
70
0 2 4 6 8 10 12 14 16 18 20 22 24
Time (hr)
Cu
mu
lati
ve
(%
) D
rug
Re
lea
se
Percent drug release of uncoupled SLN
Percent drug release of ferritin coupled SLN
In vitro Release Study
Cell Uptake Study
Fluorescence microscopic images of
(A) Fr coupled SLN and (B) uncoupled SLNs
Doxorubicin loaded ferritin coupled
SLNs were successfully developed and
characterized. In-vitro release study clearly shows
that incorporation of doxorubicin in
SLNs decreases the rate of release
therefore the drug remains for longer
duration of time in the body. Conjugation of ferritin to the
pegylated SLNs enhance in vitro cell
uptake upto 10.4 times as compared to
uncoupled pegylated SLNs. The Fluorescence microscopy further
confirms the higher uptake of ferritin
coupled SLNs in MDA-MB-468 breast
cancer cell lines. Therefore, the developed system
appear promising in the cancer
treatment by selectively targeting the
tumour cell lines. The results warrant
further evaluation of this delivery
system.
CONCLUSIONS
REFERENCES
National Conference on Impact of Nanotechnology on Drug Discovery & Development, Shimla 2011
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