R.K.Pandey, Regional
Sericultural Research Station, Jammu 181101, pandeyjammu@gmail.com
What is
Nanotechnology?
Nanotechnology,
"the manufacturing technology of the 21st century," is defined as the
understanding and control of matter at dimensions of roughly 1 to 100
nanometers (billionths of a meter, or 10 m.) A nanometer (nm) is one-billionth
of a meter, or a millionth of a millimeter - smaller than the wavelength of
visible light and a hundred-thousandth the width of a human hair. At this
scale, unique properties of materials emerge which can be applied to produce
technologies and products with entirely new abilities and applications.
Nanotechnology (NT) involves imaging, measuring, modeling, and manipulating
matter only a few nanometers in size. Nature already uses nanotechnology in the
molecular machinery of every living thing. Nature's designs are working examples
to us of what can be made. However, rather than using trial and error, we can
apply intelligent design principles to our creations.
The Nano Age
According to futurist
and inventor, Raymond Kurzweil, the Nanotech Age is expected to begin between
2025 and 2050, bringing an end to the current Information Age which began in
1990. Coming is a Nano Revolution that
will be at least as transformative as the Industrial Revolution (perhaps much
more so), but packed into just a few years. Well beyond present-day nanotech
applications, mature "molecular manufacturing" or "molecular
nanotechnology" will enable us to manifest our dreams (or nightmares). We
are nearing the ability to build molecules out of atoms mechanochemically, and
to use these molecular building blocks to construct virtually any substance or
device we can conceive of. This most powerful technology of all will radically
transform and extend the capabilities of practically every area of human
endeavor by exploring the ultimate limits of fabrication. Nanotechnology will
become the most powerful tool the human species has ever used. With it, we will
literally fashion the world of tomorrow into whatever we so desire.
Nanomaterials
Materials having
morphological features smaller than 100 nm in at least one dimension are Nan
materials. This classification includes thin films, quantum dots, etc. When
matter is reduced to the nanoscale (1 - 100 nm,) the effects of increased
surface-area, in tandem with quantum effects, begin to dominate material
properties. As a particle's size decreases, a greater proportion of its atoms
are found at the surface compared with those inside. Larger surface area equals
greater reactivity. Quantum confinement results in size-dependent property
changes, meaning materials with nanoscale dimensions (Nano materials) can start
to exhibit very different optical, electrical and magnetic properties,
(especially as the structure or particle size approaches the smaller end of the
nanoscale) compared to what they would on a macroscale. This effect has been
likened to an expansion of the entire periodic table of the elements out into
another dimension; as though we now have access to many new primary elements
which did not exist before, enabling unique/novel applications. For instance,
when made into nanoparticles, opaque substances may become transparent
(copper); inert materials attain catalytic properties (platinum); stable
materials turn combustible (aluminium); solids become liquids at room
temperature (gold); insulators turn into conductors (silicon). Materials such
as gold, which are chemically inert at normal scales, can serve as a potent
chemical catalyst at the nanoscale. Much of the fascination and potential of
nanotechnology stems from these unique surface area and quantum phenomena
exhibited by matter at the nanoscale. Silk thread is a double strand of the fibroin held together by a substance which is gummy in nature; this gummy substance is the sericin protein. The chemical composition of silk filament is fibroin (70-80%), sericin (19-28%) and other matter plus ash contributes to (1.0-2.0%).
Nano silk sericin
Nano silk sericin
 |
Fig.1 Silk filament
|
The waste water of degumming process of silk
industry is utilized for the extraction of sericin group of proteins and its
conversion to nano particles.
Extraction of
sericin
The 5 L waste water is centrifuged in a
centrifuge at 4000 rpm for about 10 minutes to remove the suspended particles.
The clear supernatant is concentrated in a rotary evaporator to about half of
the original volume 2 L. The clear concentrated sericin solution is stored at
4oC for further use.
Preparation of nano
sericin
The 48 g of urea is
added to a 100 ml concentrated sericin solution to make the final concentration
of urea to 8M. The solution is agitated continuously at 60oC for one hour.
After cooling at room temperature, the solution is dialyzed using dialysis
tubing against distilled water for 48 hrs. The distilled water is changed every
3 hrs, to remove urea completely. The solution is then subjected to
lyophilization using Opera freeze dryer at
-55 0C for 24hrs to get nano sericin in powder
form. It contains 18 kinds of Amino Acids, including all 8 kinds of human
needful ones.
APPLICATIONS
The sericin in nano form can be used in
various applications. Recently, Silk sericin has been widely used in
biomaterial applications due to its biocompatibility, biodegradability, and
anti-oxidative and bioactive activities.
Cosmetics
Because the hydrophilic
amino acids proportion reaches 80%, it has extraordinary excellent performance
on humidity-control and skin protection as cosmetic materials. The colloid
proteins protect and care one's skin and hair, forming the protective velum,
keeping the skin moisture, preventing injury on skin stratum corneum and
blocking off ultraviolet radiation. The sericin has good moisture absorbing
characteristics so it can be used as a moisturizer in the cosmetics and it also
gives glow to the skin. The sericin
shows gelling property at all conditions. This property can be used to replace
the artificial binding agent used in perfume sticks. By making the sericin
stable it is possible to increase the porosity in the perfume sticks which
makes it easy for burning.
Wound healing
One of the major
applications of tissue engineered skin substitutes for wound healing is to
promote the healing of cutaneous wounds. As the sericin based hydrogel has the
three dimensional cross linking property, it can be used as a scaffold in the
tissue engineering effectively.
Anti microbial
products
The sericin shows
antibacterial properties. It can be widely used in the pharmaceutical products
as an antibacterial agent. It is an excellent treatment for the cuts, wounds,
burns, sores and skin infections. The sericin based hydrogel can be used in
these applications as it can absorb moisture and has antimicrobial property.
This property can be utilized to prevent the urinary tract infections. The
anti-microbial activity of the Silk Sericin capped silver nitrate against
gram-positive and gram-negative bacteria is confirmed.
Sericin is also
reported to have diverse biological activities, such as anti-oxidation,
anti-bacterium, anti-coagulation and promoting cell growth and differentiation.
In the field of regenerative medicine, owing to its biodegradability, easy
availability, and hydrophilicity with many polar side groups, sericin is mostly
copolymerized, crosslinked, or blended with other polymers to form various
scaffolds in order to help obtain improved properties for relevant biomedical
applications, such as skin regeneration. Besides being jointly fabricated with
other biomaterials, the possibility of using only pure sericin to generate
scaffolds has just begun to be explored.
Facial mask paste
from silk sericin
Acne, blackheads, white
heads and blemishes are a problem that everyone at some point in their life has
dealt with and not just in their youth. These issues affect people of all ages
for various reasons. Hydrogel Mask provides superior quality over the
conventional Serum-soaked cloth masks. Before the hydrogel masks appeared on
the market, serum-soaked cloth masks were synonymous with the face masks,
appealing to consumers with their ease of use and the great hydrating ability.
Despite these merits, some users complain that they do not completely make
contact with their skin or some essence ingredients run from the face.
Compared with the
traditional standard essence masks, Hydrogel Mask provides extraordinary
moisturizing quality that has been proven to be superior to the traditional
essence masks by up to 18%.
What’s more, the new
concept Thermo-Sensible Water-Soluble gel mask gradually melts its active
ingredients into skin, reacting to the skin temperature. Genic has obtained
patents regarding thermosensible quality and TCD (Transdermal Cosmetic Delivery
System). It also utilizes the bio-matrix method, which is safe for the human
body.
This gel mask has a
great cooling effect and it keeps skin moisturized as well. The enhanced
moistness and adhesive ability guarantees effective delivery of active
ingredients into the deeper skin without damage, while resolving the problem of
other sheet-type masks’ losing active ingredients.
 |
| Fig.2 Silk sericin facial mask |
Even though
nanotechnology is an emerging field of science greatly exploited in different
sectors mainly electronics, energy, environment and health, its application in
sericulture is rarely exploited in India and abroad. The research in this
sector in India is still at a preliminary stage and also at a conceptual level
to understand realistic assessments.
Reference
International
Conference on Nano Science and Nanotechnology 2015
Int.J.ChemTech Res.7
(5), 2117-2124(2015)
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