One application of bionanotechnology

1. NANOSCALE DRUG DELIVERY SYSTEM
ANJANA PRASAD

2. NANOSCALE DRUG DELIVERY SYSTEM
• An emerging technology for the rational
delivery of chemotherapeutic drugs in the
treatment of diseases mainly cancers.
• Nano particles are used for site specific drug
delivery.
• Improve drug bioavailability .

3. BIOAVAILABILTY
• Availability of a drug at target site.
• Depends on:
1. Route of administration
2. Rate of absorption
3. Metabolism of the drug by the body

4. Fig 1: Factors that influence the bioavailability of a drug

5. GOALS OF A NANOSCALE DRUG
DELIVERY SYSTEM
Targeting, to increase the drug concentration at
desired sites of action and reduce systemic levels
of the drug and its toxic sequelae in healthy
tissues.
Improved solubility, to facilitate parenteral drug
administration.
Reduced clearance, to increase the drug half-life.

6. Constant rate of drug delivery, resulting in zero-
order release kinetics to maintain a constant
therapeutic dose at the site of action.
Increased drug stability, to reduce degradation
and maximize drug action.
Drug delivery across the blood–brain barrier
(BBB) and blood–cochlear barrier.

7. CONVENTIONAL DRUG DELIVERY
Fig 2: Barriers encountered by the drug to reach target site

8. ROUTEOF DRUG DELIVERY STATE/FORM OF DRUG DELIVERED
Oral Pill, capsule, liquid, suspension, cream
Nasal Liquid, aerosol, vapor
Ophthalmic Liquid, gel, cream, ointment, suspension
Parenteral Liquid
Topical and transdermal Ointment, gel, foam, cream, powder, liquid
Pulmonary (through lungs) Deep nasal inhalations of liquid, aerosol
Vaginal Cream, foam, solutions, gel, ointment
Rectal Suppositories (mostly torpedo shaped), cream,
foam, solution, gel, ointment
Table 1: Various routes of drug delivery and its forms

9. DRAWBACKS
• Bioavailability of drug may be less.
• Sometimes may leads to overdosage toxicity.
• Consequential inflammatory response.

10. TARGETED DRUG DELIVERY
• Aims to deliver the right of amount of drug at
only the site of disease or injury.
• Important aspect is the selection of an
appropriate delivery profile.

11. DRUG DELIVERY PROFILE
Plot of concentration of drug delivered from
vehicle with respect to time.
Varies with:
Type of drug
Type of drug vehicle
Physiological factors at delivery sites
Eg: pore size, thickness, geometry, temperature,
biodegradation etc. of vehicle determines the
amount of drug that is released.

12. Fig 3: Plot of drug concentration versus time

13. Drugs are classified into:
Carbohydrates polymers fats
amino acids lipids proteins
peptides organics peptides
Choice of drug determines how it interacts
with the vehicle and hence the delivery profile.

14. DELIVERY VEHICLES SIZE (nm)
Nanocapsules 50 - 200
Liposomes 25 - 200
Nanoparticles 25 - 200
Microemulsions 20 - 50
Table 2: Drug delivery vehicles

15. CHEMISTRY OF DRUG DELIVERY
VEHICLES
1. NANOCAPSULES
 Vesicular system in which drug is confined to
an aqueous or oily cavity surrounded by a
single polymeric membrane.
 Colloidal carriers

16. Fig 4: Nanocapsules
Outer surfactant adsortion layer.
eg: polyalkylcyanoacrylates, polylactides.
Core consist of soyabean oil or other triglycerides having
long and medium chain fatty acids.
Nanocapsule of polyisobutylcyanoacrylate (PIBCA) finds
extensive applications in drug delivery.

17. 2. LIPOSOMES
Popular vehicles used for drug delivery in treatment
of tumor and cancer.
Vesicular colloidal particles composed of self-
assembled amphiphillic molecules.
 Consist of neutral or anionic lipids which may be
synthetic or natural.
Eg: natural lipids include lecithins, sphingomyelins
synthetic includes chains of dimyristroyl, distearoyl.

18. Fig 5: Liposomes

19. Size is a prominent factor that determines the
targeting efficiency and the associated therapeutic
effects in liposomes.
Size determines the liposomal accumulation in
tumor site, efficacy of therapy, level of toxicity, cross
vessel permeation and overall transport in the body.
Lesser the size better the extent of targeting and
efficacy of therapy.
Liposomes of 100 nm size and less have exhibited
better targeting and accumulation in tumor site.

20. 3. NANOPARTICLES
Collection of several atoms of a particular
element in a given fashion.
NP of gold, silver, zinc oxide, titania etc. finds
excellent applications in bionanotech.
When functionalized with antibodies, these
nanoparticles can perform targeted delivery.

21. NP is employed as drug delivery vehicles and
biomarkers of tumors and cancer cells.
Having high “enhanced permeability and retention”
(EPR), they are much preferred for tumor and
cancer therapy.
• Alginate NPs are one other type of the class of
nanoparticles being extensively used for drug
delivery

22. 4. MICROEMULSIONS
Clear, stable, isotropic mixtures of oil, water
and surfactant, frequently in combination with
a cosurfactant.
Spherical micelle, rod-shaped micelle,
hexagonal phase, lamellar phase, reverse
hexagonal phase, and reverse micelle.

23. Fig 6: Various microstructures in microemulsions

24. CANCER TREATMENT BY MAGNETIC
HYPERTHERMIA
Very efficient and non invasive approach to treat
cancer.
Used as a supplementary treatment to radiotherapy
and chemotherapy.
The tumorous cells are destroyed at elevated temp
(42 –46ᵒC).

25. Magnetic NPs specifically Fe₂O₃ (10nm radius)
coated with cancer specific biomolecules
injected into the bloodstream near tumor.
NPs attach and accumulate the tumor cells.
Once attched, the NPs are subjected to an
alternating magnetic field for 15- 60 min to gain
and mainatin the temperature range of 42 –
46ᵒC

26. The phenomenon of heat generation that results
from magnetic particles reacting to alternating
magnetic field is known as HYSTERESIS LOSS.
When ferromagnetic substances are subjected o a
magnetic field, the particle will align according to
the field.
For alternating field, the particles are constantly
realigning to match changing field.

27. After realignment the energy used for the
alignment is released during relaxation.
The released energy dissipates as heat.

29. LOOKING FORWARD!!!!!!!!
• Nanoscale drug delivery vehicles are
promising candidates over conventional
systems due to:
Biocompatibility
Low toxicity
Lower clearance rates
Ability to target specific tissues
Controlled release of drugs

30. • Full potential of these emerging technologies has
not yet been fully recognized.
• Toxicology of nanomaterials in humans needs to be
fully studied and evaluated.
• Studies so far have been small and limited to short
term exposure; few looked at wider impact.
LOOKING FORWARD!!!!!!!!

31. • The reproducibility of batches of drug
formulations such as liposomes and NPs also
needed to be refined.
• They are just beginning to make an impact in
chemotherapy owing to the dual drive to
reduce toxicity and side effects and increasing
efficacy by selective targeting tumors.
LOOKING FORWARD!!!!!!!!

32. REFERENCES
1. Parthasarathy Aravind, Papazoglow;
Bionanotechnology; 1st edtn 2007; Nano drug
delivery; page no: 31-43.
2. Malam Yogeshkumar, et al; Liposomes and
nanoparticles: nanosized vehicles for drug
delivery in cancer; e journal; 2009.
3. Kraus H. Robert, Bradford Wright; Magnetic
nanoparticles in cancer diagnosis and
hyperthermic treatment.

33. 4. Jenny Wu, Xuanyi Ma, Yuchen Wang;
Hyperthermic cancer therapy by magnetic
nanoparticles; 2013;e journal.
5. Labhasetwar Vinod, Diandra; Biomedical
applications of nanotechnology; 2007.