New
gel-based drug delivery system developed
A
new drug-delivery gel that releases the drug in response to pressure applied by
the patient has been developed by Japanese scientists.
Drugs
are generally taken by oral administration, injection, etc. However, the
conventional methods may cause side effects and inconvenience. Although
stimuli-responsive drug delivery systems are an effective technique that takes
care of such problems, a special device is necessary in order to apply the
stimulus.
A
research group headed by Katsuhiko Ariga, principal investigator, Kohsaku
Kawakami, scientist, and Hironori Izawa, a post-doctoral researcher (currently
assistant professor, Tottori University) of the NIMS International Center for
Materials Nanoarchitectonics (MANA) succeeded in developing a gel material
which is capable of releasing drugs in response to pressure applied, Science
Daily reports.
The
MANA research group developed a gel material envisioning a new drug
administration method in which the drug is released when the patient applies
manual pressure to the gel, reports Science Daily. Using samples of the gel
containing the anti-emetic drug ondansteron, the researchers confirmed that the
drug was released when stimulus mimicking finger-pressure by the patient was
applied, and found that this effect was maintained for at least three days.
Oral
administration of drugs is difficult for patients experiencing nausea during
cancer chemotherapy. If the material is introduced under the skin, it is
expected to release the drug simply by pressing or rubbing it. It will also be
possible for patients to administer drugs under any environment at their own
intention.
For
relief from cancer pain, hay fever, or asthma, patients may need to administer
drugs quickly. Those are among the situations when this material offers an
extremely convenient new dosing strategy.
Source:
http://health.india.com
19.03.2013
Universal
vaccine against influenza possible?
A
combination of immune cells and antibodies could pave the way for a universal
vaccine against influenza, says a study.
Seasonal
epidemics of influenza result in nearly 36,000 deaths annually in the US,
according to the Centers for Disease Control. Current vaccines against the
influenza virus elicit an antibody response specific for proteins on the
outside of the virus, specifically the hemagglutinin (HA) protein.
Yearly
vaccines are made by growing the flu virus in eggs. The viral envelope
proteins, including HA are cleaved off and used as the vaccine, but vary from
year to year, depending on what flu strains are prevalent. However, high
mutation rates in envelope HA proteins result in the emergence of new viral
types each year, which elude neutralization by pre-existing antibodies in the
body.
On
the other hand, other immune cell types are capable of mediating protection
through recognition of other, more conserved parts of HAs or highly conserved
internal proteins in the influenza virus, reports Science Daily.
E.
John Wherry, PhD, associate professor of Microbiology and director of the
Institute for Immunology at the Perelman School of Medicine, University of Pennsylvania,
and colleagues, report in PLOS Pathogens that influenza virus-specific CD8+ T
cells or virus-specific non-neutralizing antibodies are each relatively
ineffective at conferring protective immunity alone. But, when combined, the
virus-specific CD8 T cells and non-neutralising antibodies cooperatively elicit
robust protective immunity. This synergistic improvement in protective immunity
is dependent, at least in part, on other immune cells — lung macrophages and
phagocytes.
An
implication of this work is that immune responses targeting parts of the virus
that are not highly variable can be combined for effective protection. ‘The
two-pronged approach is synergistic, so by enlisting two suboptimal vaccine
approaches, we achieved a better effect than each alone in an experimental
model,’ says Wherry. ‘Now, we are rethinking past approaches and looking for
ways to combine T-cell vaccines and antibody vaccines to make a more effective
combined vaccine.’
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