1. A REPORT ON
DRUG ENCAPSULATION AND DRUG DELIVERY
IN CANCER TREATMENT
Implant Training at Department of Nuclear Physics
School of Physical Sciences
University of Madras
(from 08-06-2015 to 18-06-2015)
Submitted by
Ms. S. Jenisha Chris
Reg.No. 201410039
Department of Biotechnology
Rajalakshmi Engineering College
Thandalam
Chennai – 602 105.

2. INTRODUCTION:
Cells in our body continuously divide and form daughter cells, which undergo differentiation to
perform specified functions. Cell cycle includes an interphase, S-phase and M-phase. In order to maintain
a balance in cell growth, some cells undergo (PCD) programmed cell death. It eliminates unnecessary cells
and worn out cells. Unchecked cell growth and multiplication produce a mass of cells, a tumor.
Neoplasia:
Neoplasia is the abnormal proliferation of cells. Proliferation of cells is due to “inactivation of
tumor suppressor genes and activation of oncogenes”. Malignant neoplasm is called cancer.
Figure 1. Formation of Cancer Cells
CHARACTERISTICS OF CANCEROUS CELL:
 Proliferation: insensitivity to antigrowth signals.
 Hypoxia:inadequate oxygen supply due to consumption of oxygen by proliferating tumor cells.
 Metabolism: anaerobic glycolysis.
 pH: acidic due to lactic acid production.
 Resistance to immune response: acidic pH reduces cytotoxic T lymphocytes function.
These characteristics of cancer cells make the highly resistive to host immune system. Hence
external treatment has to be given to kill cancer cells.
TREATMENTS OF CANCER:
1) Operative Methods:
 Removal of the tumor lump or infected portion of the organs
 Disadvantage: Complete cure not possible.

3. 2) Radiation:
 Exposing the cancerous region to high dosage of X-rays. X-rays affect the DNA of the cells.
 Disadvantage: Kills both cancerous as well as normal cells.
3) Stem cell therapy:
 Use of stem cells (pluripotent) to replace infected tissues and organs.
 Employed in cases of leukemia and lymphoma.
 Disadvantage: miss calculation in injection leads to unwanted growth of cells. Side effects
such as infection by microbial flora of the body and rejection in case of donor stem cell usage
may occur.
4) Chemotherapy:
 Injection of anticancer drugs which selectively kill cells dividing at an uncontrolled rate.
 Disadvantage: Inability to differentiate between normally dividing cells and cancer cells.
ANTICANCERDRUGS
All anticancer drugs act on cancer cells and kill it by damaging the part of the cell’s control center
that makes it divide. It interrupts the chemical processes involved in cell division.
Major types include:
 Alkylating agents
 Antimetabolites
 Antitumor antibiotics
 Mitotic inhibitors
Alkylating agents:
These drugs damage the DNA of the dividing cells there by it prevents the metabolism of the
cells.
Examples: Mechlorethamine, cyclophosphamide, busulfan dacarbazine, altretamine.
Antimetabolites:
These cells affect the S-phase of the cell cycle during which doubling of chromosomes takes
place. It interferes with the formation of two sets of chromosomes there by preventing the daughter cell
formation.
Examples: 5-flurouracil, 6-mercaptopurine Cytarabine, Gemcitabine Hydroxyurea, Methotrexate.
Antitumor antibiotics:
These drugs alter the DNA of the cell by interfering with the activity of enzymes involved in
synthesis of DNA.
Examples: Anthracyclins, actinomycin-D, mitomycin-C, bleomycin.

4. Mitotic inhibitors:
These drugs affect the M-phase of the cell cycle where mitotic cell division takes place.
Examples: Paclitaxel, vinblastine, ixabepilone.
DRUG DELIVERYSYSTEM:
Drug delivery refers to approaches,formulations, technologies, and systems for transporting
a pharmaceutical compound in the body as needed to safely achieve its desired therapeutic effect. It
involves scientific site-targeting within the body.
Importance ofdrug delivery system:
Drugs have side effects especially those used for cancer treatment as they lack the ability to
differentiate between cancerous and normal cells. Side effects are caused when drugs act on the normal
cells. In order to overcome this, drug delivery system was introduced.
Routes ofdrug delivery system:
Oral, inhalation, absorption through skin and intravenous injection.
Drug delivery system focusses on two main aspects:
 Delivery of drug only to the target.
 Sustained release of drug at controlled rate.
Types:
 targeted drug delivery
 sustained drug delivery
 controlled drug delivery
Targeted drug delivery:
It is a type of drug delivery system where the drug is selectively targeted or delivered only to its site
of action or absorption and to the non-target organs, tissues or cells.
Advantages:
 Increase of concentration only at the target.
 Higher efficiency.
 Reduced side effects.
 Usage of desired concentration of drug.

5. Figure 2. Target Delivery of Drug molecules
Methods of Drug targeting:
 Active targeting by carrier proteins and antibodies.
 Ligand mediated targeting by signal triggering molecules.
 Physical targeting by ph, temperature,light, electric field, ionic strength and stimuli.
 Passive targeting by physiochemical properties.
 Dual targeting carrier acts as drug.
Sustained drug delivery:
The drug delivery system that are designed to prolonged therapeutic effect by continuously
releasing medication over an extended period of time after administration of a single dose.
Advantages:
 Reduced fluctuation in drug level in blood.
 Reduced dosing frequency.
 Maximum bioavailability in minimum dosage.
 Reduced hospitality time.
Characteristics ofsustained formulations:
 Biological half-life : Average
 Dosage : Minimum
 Side effects : No
 Solubility : Good
 Stability : High
 Nature : Weakly acidic
 Encapsulation : Waxes,shellac and zein, ethyl cellulose.
 Localization : No
Controlled drug delivery:
Controlled release is release of the drug at a predetermined rate in order to maintain a constant
drug concentration for a specific period of time.

6. CARRIERS:
Carriers are substances on which drugs are carried to the targeted site and released in the desired
way in order to have a therapeutic effect.
Characteristics ofcarriers:
 Biocompatibility
 Biodegradable
 Non-toxic
 Non-immunogenic
Important carriers used:
Liposomes, lipoprotein-based drug carriers,nanoparticle drug carriers,dendrimers.
Figure 3(a) Liposome without Drug Figure 3(b) Drug loaded Liposome
NANOMATERIALS
Figure 4(a) Drug loaded CNT Figure 4(b) Drug loaded gold nanoparticle
The use of nanoparticles in the biological field has increased due to the superior properties that they
possesswhen compared to their bulk counterparts such asenhanced permeability and retention and the ease
with which they are taken up by the cells. Apart from this, nanoparticles own a functional surface which
gives the nanoparticles the ability to bind, adsorb and carry other compounds thus making them suitable for
drug delivery. Ofthese nanoparticles, noble metal nanoparticles are preferreddue to their optical properties,

7. nontoxicity and biocompatibility when compared to other metals. Majorly, iron, gold, silver and platinum
nanostructures are the most extensively studied examples of metal nanodrugs which have the ability to
convert light or radio frequency into heat thus enabling the thermal ablation of the targeted cancer cells.
Palladium is a noble metal with remarkable catalytic, mechanic and electronic properties. Palladium
nanostructures have gained interest in the last decade in a number of applications including catalysis, as
sensors for the detection of various analytes. In medicine, palladium is nowadays commonly used in dental
appliances, it is also used as an effective carrier in drug delivery system. One major drawback that arises
while using Pd nanoparticles is its agglomeration during reduction from its metal salts. Thus, an effective
way to prevent the aggregation of Pd nanoparticles is mandatory. An effective strategy for this would be
the use of stabilizing agents or surfactants. The most promising and environment friendly stabilizing agents
are enzymes and polymers.
The role of stabilizing agent or surfactant is played well by chitosan. Chitosan is a
linear polysaccharide composed of randomly distributed β-(1-4)-linked D-glucosamine
(deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit). It is made by treating shrimp
and other crustacean shells with the alkali sodium hydroxide. Chitosan is a biopolymer that is
biocompatible, biodegradable, ecofriendly, ntoxic and has NH2 and OHgroups which actsaschelating sites
for drugs.
Moreover, as the combination of nanoparticles with chitosan in the form of nanocomposite matrices
provide a high surface area required to achieve high loading of enzymes, drugs and compatible micro
environment to facilitate the stability. A nanocomposite system consisting of both palladium and chitosan
will encompass the properties of both the moieties, which makes it a powerful choice for use in
biocompatible targeted delivery and sustained release.
CHITOSAN/PALLADIUM (CS/Pd) NANOCOMPOSITE:
Preparation of CS/Pd Nanocomposite:
Chitosan was dissolved in 2% acetic acid to obtain a polymer solution at a concentration
of 0.34% (w/v). The solution was then filtered and used further. Amount of Palladium (II) acetate
was chosen such that the composite would contain 5% - 15% (w/w) palladium i.e. the amount of
palladium would be 5% of the weight of chitosan for the CS/Pd [5 weight% (5 wt%)] case, 10%
the weight of chitosan for the 10 wt% case and similarly 15% the weight of chitosan for the
15 wt% case. The calculated quantity of palladium (II) acetate was added to the chitosan solution
kept under simultaneous stirring and sonication. The pH of the solution was found to be ~2 to 3.
The required quantity of NaBH4 was added drop by drop to the above mixture and allowed to
disperse in the chitosan solution for about 5 h after which the solution was centrifuged and the
particles were collected. A flow chart depicting the synthesis of CS/Pd is given below.

8. Figure 5. Flowchart representing the synthesis of CS/Pd nanocomposite.
5-flurouracil (5-FU) is the drug used in this work. It is an antimetabolite affecting the S-PHASE
of the dividing cancer cell. It brings about death of cancer cells by interfering with the synthesis
and doubling of chromosomes, during formation of the daughter cells.
Protocol for the synthesis of 5-FU encapsulated CS/Pd Nanocomposite:
Chitosan was dissolved in 2% acetic acid solution to maintain chitosan concentration at
0.75 (mg/ml). Prepared chitosan solutions were mixed with 3.8 mM 5-FU solutions (5-FU
dissolved in water). Tween 80 (0.5% (v/v)) was added to the above solution, and the pH was
maintained between 4.6 and 4.8. Prepared 5-FU containing chitosan solution was mixed with
1.4 mM TPP solutions such that ratio of chitosan to TPP is (2: 1) (v/v). The nanoparticle suspension
was gently stirred for 180 min at room temperature to allow 5-FU adsorption on the nanoparticles.
Palladium (II) acetate was added to the above solution. The required quantity of NaBH4 was added
drop by drop to the above mixture and allowed to disperse for about 5 h. A solution of 5-FU
encapsulated CS/Pd nanocomposite thus obtained was centrifuged, resuspended in water, freeze-
dried and the powder obtained was used for further analysis.
0.3404 g of CS dissolved in 98 ml of distilled water + 2 ml acetic acid
Required amount of Palladium (II) acetate solution was added
NaBH4 was added drop by drop in the above mixture and dispersed
for 5 h
Centrifuged and CS/Pd nanocomposite was collected

9. Figure 6. Flowchart representing the synthesis of 5-FU encapsulated CS/Pd
Drug Release Protocol:
The release of 5-Fluorouracil (5-FU) from the nanocomposite systems was analyzed by
using the dialysis bag technique. Of all the methods used to assess drug release from nanosized
dosage forms, the dialysis method is the most versatile and popular. In this method, physical
separation of the dosage forms is achieved by the usage of a dialysis membrane which allows for
ease of sampling at periodic intervals. The drug encapsulated nanocomposite is introduced into the
dialysis bag containing release media. The release media that we have used is the phosphate buffer
saline solution (PBS). The dialysis bag is sealed and placed in a beaker containing 60 ml PBS
which is maintained under stirring to minimize the unstirred water layer effects. The volume
enclosed in a dialysis bag is ~ 2 ml which is significantly smaller than the outer media. The drug
released from the nanocomposite diffuses through the dialysis membrane into the solution kept in
the beaker. This solution is collected at regular intervals inorder to study the release.
The dialysis bag used in this study was purchased in the form a 1 feet roll. So the required
amount was first cut and was washed in running tap water for about 45 min, after was it was kept
soaked in distilled water for 2 h after which it was used. The choice of dialysis bag was made such
0.3404 g of CS dissolved in 98 ml of distilled water + 2 ml acetic acid
Solution of 5-FU is added
Solution ofTPP is added followed by tween
Required amount of Palladium (II) acetate added to the above solution
NaBH4 was added drop by drop in the above mixture and dispersed for 5
Solution freeze dried and 5-FU@CS/Pd nanocomposite collected
Simultaneous stirringand sonication
Simultaneous stirringand sonication
Simultaneousstirringand sonicationfor 2 hrs

10. that the molecular weight cut off (MWCO) was apt for the release of the drug alone into the PBS
Solution kept in the beaker. The MWCO of the dialysis bag used for the release studies in this case
was 1000 Da. 3 ml of PBS was collected from the beaker at regular time intervals and replaced
with fresh PBS solution. The collected solution will be analyzed using UV-Vis and the amount of
5-FU released during that time interval will be calculated.
CONCLUSION:
Chitosan/palladium nanocomposite and 5-FU encapsulated nanocomposite was
successfully prepared using the chemical reduction method. Drug release profile was studied.
Further, this nanocomposite material can be used in cancer treatment for effective targeting and
sustained release of drug.
REFERENCES:
1. Palladium: a future key player in the nanomedical field, Anaëlle Dumas and Patrick Couvreur, Chem. Sci., 2015, 6,
2153-2157.
2. An in vitro cytotoxicity study of 5-fluorouracil encapsulated chitosan/gold nanocomposites towards MCF-7 cells,
E.A.K. Nivethaa, S. Dhanave, V. Narayanan, C. Arulvasu, A. Stephen, RSC Adv., 2015,5,1024.