Transcript Young Innovators 2009

YOUNG INNOVATORS 2009
Sustained Release Curcumin
Microspheres for Inhibition of
Breast Cancer
Komal Shahani 1,2, Jayanth Panyam 2
1 Wayne State University
2 University of Minnesota
ABSTRACT
Curcumin, a dietary polyphenol, has demonstrated chemopreventive potential in
vitro in several breast cancer cell lines. However, curcumin suffers from poor
oral bioavailability (<1%) and short half-life in vivo, resulting in sub-optimal
plasma concentration. The inability to achieve effective systemic concentration
following oral administration limits curcumin’s therapeutic and preventive
potential in breast cancer. We hypothesized that increased and extended systemic
availability of curcumin following subcutaneous administration of a sustained
release microsphere formulation will result in effective inhibition of breast
cancer. Curcumin-loaded PLGA microspheres were prepared by a rapid solvent
evaporation process designed in our laboratory. Microspheres were characterized
for size, morphology, drug loading, and in vitro release of curcumin.
Pharmacokinetics of the sustained release microsphere formulation was
determined in BALB/c mice. The tumor inhibitory potential of the sustained
release microsphere formulation was determined in female BALB/c nude mice
bearing MDA-MB-231 (human breast adenocarcinoma) xenografts.
Young Innovators 2009
ABSTRACT
The rapid solvent evaporation process enabled the production of PLGA
microspheres with high curcumin loading (~38% w/w; 75% encapsulation
efficiency) and sustained release properties (80% release over 28 days). SEM and
bright field microscopy studies of the microspheres indicated a smooth, spherical
morphology and an average diameter of 22 ± 9 µm. When injected
subcutaneously in BALB/c mice, a single dose of curcumin-loaded PLGA
microspheres sustained curcumin blood levels for a period of 4 weeks.
Interestingly, curcumin concentrations in the lungs and the brain were higher
than that in blood and were similarly sustained through 4 weeks. High and
sustained levels of curcumin in these organs suggest that curcumin could
potentially inhibit breast cancer metastases to these organs. A single dose of
curcumin microspheres injected subcutaneously significantly inhibited the
growth of MDA-MB-231 tumors (compared to a single dose of blank
microspheres, intraperitoneal injections of curcumin solution and vehicle control
administered thrice a week, P < 0.05) over a period of 4 weeks. We have
successfully demonstrated extended systemic availability of curcumin following
subcutaneous administration of a sustained release microsphere formulation and
established its tumor inhibitory potential in a mouse model of breast cancer.
Young Innovators 2009
CURCUMIN
• Dietary polyphenol derived from root of Curcuma
longa (Turmeric)
• Antioxidant and anti-inflammatory activities
• Widely used in Indian medicine and curries
• Shown to suppress, arrest, or reverse the process
of carcinogenesis
Young Innovators 2009
PRECLINICAL AND CLINICAL EFFICACY
OF CURCUMIN
• Poor oral bioavailability (< 1%)
• High oral doses (8 g/day) in humans result in Cmax
of < 2 M
• Short half life (~28 minutes)
• Limits potential in breast cancer
Young Innovators 2009
PRECLINICAL AND CLINICAL EFFICACY
OF CURCUMIN
• Daily intraperitoneal injections of curcumin have
been shown to inhibit DMBA induced mammary
tumors in rats
• Frequent systemic dosing is not a preferred
modality for breast cancer prevention and therapy
Young Innovators 2009
HYPOTHESIS
• Increased and extended systemic availability of
curcumin following subcutaneous administration
of a sustained release microsphere formulation will
result in effective inhibition of breast cancer
Young Innovators 2009
METHODS
• PLGA microspheres with high curcumin loading
were fabricated by a rapid solvent evaporation
process designed in our laboratory
• Microspheres were characterized for size and
morphology using bright field and scanning
electron microscopy (SEM), and for drug loading
and in vitro release of curcumin using HPLC
• Physical state of the encapsulated drug was
determined by differential scanning calorimetry
(DSC)
Young Innovators 2009
METHODS
• Pharmacokinetics of the sustained release microsphere
formulation was determined in BALB/c mice
• Curcumin concentrations in blood and tissues were
determined by LC-MS/MS
• Tumor inhibition studies were carried out in female
BALB/c nu/nu mice bearing MDA-MB-231 (human
breast adenocarcinoma) xenografts
• Immunohistochemistry studies were done on tumor
samples. Cleaved caspase-3, Ki-67, and CD31 were used
as biomarkers of apoptosis, proliferation, and
angiogenesis respectively
Young Innovators 2009
RESULTS
• PLGA microspheres with high curcumin loading
(~38% w/w; 75% encapsulation efficiency) were
fabricated
• Microspheres had a smooth, spherical morphology
and an average diameter of 22 ± 9 µm
• Curcumin loaded in microspheres maintained its
crystallinity, indicated by a melting peak at 183° C in
the DSC thermogram
• Microspheres sustained release of curcumin in vitro
over a one-month period (80% release over 28 days)
Young Innovators 2009
RESULTS
• In mice, a single intraperitoneal injection of
curcumin solution resulted in rapid clearance (t1/2
7 hours) of curcumin from blood
• Intraperitoneal injections of curcumin solution
administered thrice a week resulted in peaks and
troughs in curcumin blood levels
• A single subcutaneous dose of microspheres
sustained curcumin blood levels for a period of 4
weeks
Young Innovators 2009
RESULTS
• Blood levels with the microsphere formulation were
similar to that seen at the end of a week following
thrice a week intraperitoneal injections of curcumin
solution
• Curcumin levels in the lungs and the brain were 1030-fold higher than in blood
through 4 weeks
and were sustained
• Histological evaluation of the subcutaneous tissue
from vicinity of the injection site showed that
presence of curcumin mitigated acute inflammatory
response to PLGA microspheres
Young Innovators 2009
RESULTS
• In nude mice, a single subcutaneous dose of curcumin
microspheres significantly inhibited growth of MDAMB-231 tumors compared to other controls over a
period of 4 weeks
• Intraperitoneal injections of curcumin solution
administered thrice a week had no effect on tumor
growth
• Immunohistochemistry studies demonstrated that
curcumin microsphere treatment significantly
increased the number of apoptotic cells, and decreased
the number of Ki-67+ and CD31+ cells
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DISCUSSION
• A single intraperitoneal injection of curcumin solution
resulted in rapid clearance of curcumin from blood due
to its short half life
• Multiple intraperitoneal
injections of curcumin
solution resulted in peaks and troughs in curcumin
blood levels
• Blood levels were highest at 30 minutes post injection
followed by a decline to near detection limits within 24
hours
Young Innovators 2009
DISCUSSION
• A single dose of curcumin microspheres was found to
sustain curcumin levels in blood for 4 weeks
• Curcumin penetrates the lungs and the brain well due
to its highly lipophilic nature
• This observation is significant because lungs and brain
are often the sites for metastases in breast cancer
• High and sustained levels of curcumin achieved in
these organs could potentially inhibit breast cancer
metastases to these organs
Young Innovators 2009
DISCUSSION
• Encapsulation of curcumin in microspheres was
found to cause a profound change in
pharmacokinetics of the drug
• Longer half life (35-fold) and mean residence time
(51-fold) values observed with microsphere
formulation suggest sustained availability when
curcumin is formulated as microspheres
• A single dose of curcumin microspheres
significantly inhibited tumor growth compared to
other controls
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DISCUSSION
• Several mechanisms could account for the antitumor effect of curcumin microspheres
• Curcumin microsphere treatment significantly
enhanced apoptosis, and impaired tumor cell
proliferation and angiogenesis
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CONCLUSIONS
• The enhanced efficacy of curcumin microspheres
appears to be related to the ability of
microspheres to provide sustained curcumin
exposure to tissues of interest
• Overall, sustained curcumin delivery using
injectable microspheres is a promising approach
to breast cancer prevention and therapy
Young Innovators 2009
ACKNOWLEDGMENTS
• Dr. Peter Villalta, Mass Spectrometry Lab (UMN)
• Diana, Brenda and Angela, RAR (UMN)
• Dr. John Nelson, Characterization Facility (UMN)
• Dr. Raj Suryanarayanan and Sunny, Department of
Pharmaceutics (UMN)
• Department of Pharmaceutical Sciences, Wayne
State University
• Department of Pharmaceutics, University of
Minnesota
Young Innovators 2009
REFERENCES
• Yang KY, Lin LC, Tseng TY, Wang SC, Tsai TH. Oral
bioavailability of curcumin in rat and the herbal analysis
from Curcuma longa by LC-MS/MS. J Chromatogr B
Analyt Technol Biomed Life Sci 2007; 853: 183-9
• Cheng AL, Hsu CH, Lin JK, et al. Phase I clinical trial of
curcumin, a chemopreventive agent, in patients with highrisk or pre-malignant lesions. Anticancer research 2001; 21:
2895-900
• Thangapazham RL, Sharma A, Maheshwari RK.
Multiple molecular targets in cancer chemoprevention
by curcumin. Aaps J 2006; 8: E443-9
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REFERENCES
• Singletary K, MacDonald C, Wallig M, Fisher C. Inhibition
of
7,12-dimethylbenz[a]anthracene
(DMBA)-induced
mammary tumorigenesis and DMBA-DNA adduct formation
by curcumin. Cancer Lett 1996; 103: 137-41
Young Innovators 2009
BIOS/CONTACT INFO
Komal Shahani received her Bachelors degree in Pharmacy and
Masters degree in Pharmaceutics from the University of
Mumbai, India. She earned her Doctorate degree in
Pharmaceutical Sciences from Wayne State University, Detroit
in August 2009. She is currently a Research Associate in the
Department of Pharmaceutics at the University of Minnesota,
Minneapolis. Her doctoral research focused on the use of
polymeric, sustained release microparticles of dietary
polyphenols for breast cancer chemoprevention. She has
presented in several regional and national meetings. She is the
lead author of one published paper and two others in
preparation. She has been awarded the 2009 AAPS Graduate
Student Symposium Award in Biotechnology. She can be
contacted at [email protected]
Young Innovators 2009