provides striking promises, when applied to medical diseases
like cancer, diabetes, or Alzheimer's disease, cardiovascular
problems, infectious or inflammatory diseases. Improving the
quality of life and health of citizens require further
research on nanomedicine.
improvement in the treatment of harsh diseases has led to the
implementation of a multidisciplinary advancement to the target
specific delivery and release of drugs. This received an impetus
via nanoscience and nanotechnology. The latest drug delivery
systems combine polymer science, bioconjugate chemistry and
molecular biology. The main objective is to attain a control
over pharmacokinetics and pharmacodynamics of the applied
medicine, reduce the toxicity.
developments in drug delivery and targeting systems generally
aspire to lower drug nastiness and failure, avoid detrimental
side effects and amplify the drug-availability at the diseased
site. Nanotechnology aims at engineering the drug carriers that
include nanoparticles, nanocapsules, lipoproteins and liposomes,
to slowly decay, respond to stimuli and be target-specific. The
research of nanotechnology has lead to various developments of
various targeting mechanisms. For example special build-up of
chemotherapeutic agents in solid tumours resulting from the
differences in the vascularization of the tumour tissue makes
this property of vascularization nanoparticle specific. These
particles use this property to target the diseased tissue.
Another method known as active targeting involves a coating of
the surface of drug carriers with the nano killers thus allowing
them to get selectively adhered to problematic cells.
approach to drug delivery deal with crossing a typical physical
barrier such as the blood-brain barrier. The basic aim is to
find different suitable routes for the release of the nano
particles or protein-based drugs except for the
gastro-intestinal tract route where the drugs are subjected to
degradation. Thus nanotechnology form the basis of pioneering
delivery techniques that provide many possible advantages to
patients and also gives new definition to drug delivery system.
A result-oriented drug carrier
system should show best possible drug release properties,
refined targets and low toxicity. Nanoparticle dispersions
constituting small particles of 10 - 300 nm diameter as well as
colloidal systems, such as liquid crystal dispersions, hold a
great future as carriers in drug delivery systems.
Dendrimers are nanometre-sized,
polymer macromolecules. They have a central core and branching
units. The core chemistry decides the solubilizing properties of
the cavity within the core and the outer chemical groups
determine the chemical behavior of the dendrimer itself. Certain
linker to the outer surface of the dendrimer that allows it to
bind to a particular disease site is a way to attain targeting.
nanospheres and nanocapsules that are amorphous or crystalline
are efficiently used as drug carriers. They function by
encapsulating or adsorbing a drug and provide protection against
any kind of degradation. In nanocapsules, the basic drug is
restricted to a cavity covered by a polymer membrane, in
nanospheres, there is a matrix system in which the drug is
scattered. The structures are formulated to provide a shield to
the drug. The novel introduction of biodegradable polymeric
nanoparticles has been a miracle in the sustained release of
drugs that are target specific. This approach has also made
nanoparticles the carriers of DNA in gene therapy and their
capability to deliver proteins and genes via oral route.
vesicles that are formed of chemically active lipid bilayers and
it is these bilayers that encapsulates the drug molecules and
solubilize them within them. Moreover, certain proteins can be
included in the liposome-membrane to act as filters and allow
only the transmission of small solutes like ions, nutrients and
antibiotics. Thus, liposome here acts as a natural nanocage for
the drugs thus again protecting them from any kind of
degradation. The transmission is also allowed when there is a
concentration difference between the internal and the external
walls of the nanocage.
i.e. intravenous, intramuscular or subcutaneous routes are used
for drug-administration. Liposomes are the nanosystems that are
administered intravenously. Other nanoscale drug carriers have a
high ability for improving the drug-delivery through nasal and
sublingual routes thus avoiding the initial metabolism and
accessing otherwise directly inaccessible area like brain and
intra-articular cavities. The nasal route is now being used to
administer the drug molecules with nanoparticles thus greatly
improving the bioavailability of drugs.
Now a day
pulmonary problem is increasing, they account for more than one
third of the drug delivery market. Nanotechnology is now being
used to make drug delivery efficient in the lungs. The drugs are
delivered via various ways inhaler systems, aerosols,
powder/capsule inhalers and nebulizers, which are now revised to
contain nanostructures like dendrimers, micelles, nanoparticles
and liposomes. This route forms an effective route for
delivering protein and peptide drugs. The lung-delivery will be
a priority route for gene therapy when needed like in
untreatable diseases of fibrosis treatment.
nanomedicines for pulmonary drug delivery are great at site-
targeting for the respiratory disease treatments.
delivery is another research field for nano delivery systems. It
avoids troubles of gastrointestinal problems and the drug
degeneration. Moreover, due to minimal meddling caused by the
presence of food, the drug-delivery rate becomes more efficient.
Moreover this procedure is non-invasive and is used for local
drug delivery. Trans-tissue drug delivery systems are also
becoming popular and need to be adhered to the resected tissue
nanomedicine used produces an eminent pharmacological outcome
and minimizes any toxicity that is associated with drug
Thus use of
nanotecnology to form an effective drug delivery system in order
to minimize the drug-degradation as well as site targeting of
drugs is gaining momentum.