1. A Brief History of Silver and Silver Colloids in Medicine.
Silver has been used as a medicine and preservative by many cultures throughout history.
The Greeks, Romans, Egyptians, and others used silver vessels for water and other liquids to
keep them fresh. Pioneers trekking across the Wild West generations ago faced many
hardships. Keeping safe drinking water was one of them. Bacteria, algae, etc. found a fertile
breeding ground in the wooden water casks that were carried on the wagons. They placed
silver and copper coins in the casks to retard the growth of these spoilage organisms. They
also put silver dollars in their milk to keep it fresh.
Silver water purification filters and tablets manufactured in Switzerland are used by many
nations and international airlines. Silver is also used in the water purification systems of
space craft. Preventing the growth of algae and bacteria in swimming pools is another
problem that people face today. Electrical ionization units that impregnate the water with
silver and copper ions are available today that sanitize the pool water without the harsh
effects of chlorine.
Medical applications of silver were recognized by the ancient Egyptians, Greeks, Romans,
and in the alchemical writings of Paracelsus. Following the discovery of bacteria as a cause of
disease, several physicians discovered the antibacterial qualities of silver and applied them to
their practice of medicine. They used silver nitrate successfully in the treatment of skin
ulcers, compound fractures, and suppurating wounds.
In 1881, Carl Crede pioneered the installation of 2% silver nitrate in the eye of neonates to
prevent gonorrheal ophthalmia, a technique which has been in widespread use ever since.
Von Naegeli and others in 1893 realized that the antibacterial effects of silver were primarily
due to the silver ion. He coined the term oligodynamic to mean that a small amount of silver
is released from the metallic surface when placed in contact with liquids.
In the early 1900's silver foil dressings were used for wounds. These dressings were used
extensively until just after World War II, and were listed in the Physician's Desk Reference
In the early 1970's, Drs. Becker, Marino, and Spadaro, of the Veterans Administration
Hospital in Syracuse, New York, pioneered the study of implanted silver wires and
electrodes and silver-coated fabrics for the treatment of complex bone infections.
Dr. A. B. Flick developed broader clinical applications for silver nylon fabrics, first in
partnership with Dr. Becker and later independently. Other university centered research
teams also investigated the wound healing properties of silver plated fabrics applied with the
application of an electrical potential. The result was the commercial introduction of silver
dressings for wound healing and burns.
Silver sulfadiazine ointment is the number one treatment for burns in U.S. burn centers.
Silver coated catheters and silver heart valves are used because they stop the bacterial
growth that was commonplace with the old ones. To protect us from food poisoning, silver
particles are now being put in cutting boards, table tops, surface disinfectants, washing
machines, and refrigerators. Silver is now being used in clothing, for the military, sportsman
and businessman. It is woven and impregnated into the fabric to kill bacteria that cause body
odor and clothing odors.
In contemporary times, colloidal silver as a medicinal substance for internal use is something
of an orphan. It is popular among alternative medicine enthusiasts but is not approved by
Silver was used as a medicine in the late 1800's and early 1900's. While several metal salts
and compounds demonstrated strong germicidal properties, silver alone showed both strong
germicidal properties and low or no toxicity to humans. The colloidal state proved to be the
most effective form because it lacked the caustic properties of salts (such as silver nitrate)
and demonstrated a high level of activity with very low concentrations.
Medicinal silver compounds were in widespread use in the late 1800's and early 1900's. By
1940, there were approximately four dozen different silver compounds on the market being
used to treat every known infectious disease.
These different silver preparations were drastically different from each other. Some were
true colloids of silver, others were silver salts or other compounds of silver. Many were silver
proteinates. The actual silver content also varied widely, with some products containing as
much as 30% silver by weight.
With the discovery of antibiotics, interest in silver, as an anti-microbial medicine, declined.
2. Colloidal Silver Featured in the Wall Street Journal.
Colloidal Silver Featured In The Wall Street Journal March 2, 2009 |
Sports socks, washing machines, food containers, soap and band-aids : What do these items
have in common? Colloidal Silver, nano-sized silver particles that have been used to
manufacture everyday products by the industrial giants to kill germs, giving us a healthier
environment. Check out the leaders of the industry…
The “powers” of colloidal silver have been heralded for thousands of years only to be quieted
by penicillin and other bacteria killers conjured up in the pharmaceutical labs, given Latin
names and used to fight every bacterium originated disease known to man.
The results of shunning this natural “nano-sized” (nano = one billionth of a meter) antibiotic
has been that diseases have evolved to have a resistance to the man made antibiotics and
now scientist are scrambling to find replacements for the antibiotics that have survived less
than 100 years.
There are critics that hypothesize that the large pharmaceutical companies are pressuring
the regulatory agencies to prevent nano-sized silver products from being sold directly to the
public without the giants taking their cut. Websites have sold silver nanoparticles in solution
known as colloidal silver without the ability to mention what the product will cure or
testimonials from those that have had positive results.
Wall Street Journal announces that the “War Against Germs Has Silver Lining”.
Curad USA, makers of hospital bandages lined with nano-silver particles now has released
Curad Silver Bandages for the home use instead of a Band-aid. Curad claims “that silver
reduced bacterial growth like Staph. aureaus, E. coli, E. hirae and Pseudomonas aeruginosa”.
Samsung Electronics has introduced a refrigerator and new laundry washing machine that
uses silver ions to sanitize the laundry and eliminate 99% of odor causing bacteria (sold at
Lowe’s and Best Buy). Plank, a Boston company, has launched a new soap for Yoga users
that lists silver as the main active ingredient. The company has a toothpaste and shampoo in
R&D that is imbued with silver.
Asia has become the largest consumer of products that uses the nano-silver as a
antimicrobial ingredient. Colloidal silver is known to kill virus, is it possible they are guarding
against bird flu?
While some agencies strive to prevent you from buying colloidal silver online, the EPA is
clear that we NOW have silver in our drinking supply and has, for health purposes
established a daily reference dose for silver in drinking water at 350 micrograms (u.g) and a
critical dose at 1400 u.g. In contrast, international health bodies, such as the World Health
Organization, have not established such standards for silver since its toxicity is very low.
Silver “becomes more active against microbes when it’s made into small particles because
they can cover more surface area when they come into direct contact with bacteria,”
according to Andrew Maynard, physicist and chief scientific adviser for studies on Emerging
Nanotechnologies underway at Woodrow Wilson International Center for Scholars in
Adidas, and Polartec have licensed silver coated nylon fabric known as X-Static (Noble
Biomaterials Inc.) to incorporate antimicrobial silver in athletic and outdoor clothing for their
ability to kill odors and promote thermal properties. Brooks Sports sells a line (HVAC) of
socks, caps and shirts that use silver to differentiate them from all others.
ARC Outdoors uses silver infused fabric from NanHorizon Inc. to produce antimicrobial
socks for the U.S. military. SmartSilver is brand of odor-eliminating underwear, stocking
caps and gloves that kills bacteria on contact using nano-silver. ARC sells to Wal-Mart, Bass
ProShops, Cabela’s and wants to expand to hospital products such as sheets and surgical
Sharper Image has introduced a plastic food storage container that is infused with nano-
silver particles that they claim will keep food fresher, longer.
So what diseases will colloidal silver display benefits for? Bacteria and virus are known to be
killed by silver suspended in a liquid of nanoparticle size called colloidal silver. In addition to
the bacterial growths like Staph. aureaus, E. coli, E. hirae and Pseudomonas aeruginosa
mentioned by Curad and Maynard, yeast, fungus and virus have all died in tests using
colloidal silver. So is yeast infection a yeast? Yes. Is ringworm a fungus? Yes. Is acne caused
by bacteria? Yes. Is sinusitis caused by a bacteria infection? Yes. Is silver used in infants
eyes? Yes. Is silver used for burn victims? Yes. Is colloidal silver an immune system
support? Yes. Will colloidal silver be the answer for bird flu? Is bird flu a virus?
3. Nano Silver- The Differences of Ions, Atoms and Charged Particles.
Many non-scientific writers confuse ions and charged particles and use the terms
interchangeably when describing colloidal silver. Others refer to colloidal particles as though
they are single atoms of silver. Much has been written about silver particles having a positive
charge, which is false. It is no wonder then that lay people trying to learn about colloidal
silver become confused and have a hard time grasping the science involved with the subject
matter when so much of what they read is scientifically flawed.
Since the real science involved in understanding colloidal suspensions requires an
understanding of the underlying principles, it is important to have a clear understanding of
the differences between atoms, ions and charged particles.
What is colloidal silver and why is this important?
While a colloid can have many forms, colloidal silver is one type of colloid that consists of solid
particles suspended in a liquid. The solid is very small particles of metallic silver and the
liquid is water. Very small particles in this context refer to particles whose diameter is
measured in nanometers. A silver colloid then must have silver particles in suspension.
Colloidal silver also contains another form of silver called ions. The difference between
solutions, colloids, and suspensions is defined by the size of the particles:
solutions <10-9 m (less than 1 nm)
colloids 10-9 m to 10-6 m (1 nm to 1000 nm)
suspensions > 10-6 m ( larger than 1000 nm)
Various forms of silver
Colloidal silver is generally produced by electrolysis when an electric current is passed
through a series circuit consisting of a silver electrode and de-ionized (DI) water. The
current can be either alternating current (AC) or direct current (DC). The current flow
causes Ag0 (metal) and Ag+ (ions) to migrate from the electrode into the DI water. AC
processes tend to be more efficient than DC in limiting the ionic concentration. It is generally
assumed that water ionizes to H+ and OH-, and that the H+, in the form of the hydronium
ion, H3O+, migrates to the cathode, where it is reduced to hydrogen gas, H2, which is
liberated. The electrons taken from the cathode are replaced at the anode when Ag metal
goes into solution as Ag+.
Therefore, colloidal silver consists of silver in two distinctly different forms, metallic silver
particles and ions. The total amount of silver that is reported as the silver concentration (in
parts per million) is the sum total of the silver contained in the particles and the silver
contained in the silver ions. Accurate measurement of total silver content requires the
measurement by either atomic absorption or atomic emission of the silver atoms. An Atomic
Absorption Spectrophotometer (AAS) is typically used for accurate results. To measure the
concentration of silver ions by atomic absorption requires that the particles first be removed
by centrifugation leaving only the ions. Alternatively, an Ion Selective Electrode (ISE) can be
selected that only responds to the silver ions in solution. ISE measurements are less accurate
than AAS and are generally accurate to within about 2%. The concentration of silver particles
is determined by subtracting the ionic concentration from the total silver concentration.
Typically, silver ions make up 75 to 99 percent of the total silver while only 1 to 25 percent of
the total silver is particles. A solution containing only ionic silver and no particles is not a
colloid since there are no solid silver particles in suspension. On the other hand, if 100
percent of the silver was particles and no ions were present, the solution would be a pure
colloid. One measure of the quality of a silver colloid is the percentage of silver particles.
Ideally, all the silver content would be in the form of particles with no silver ions.
A single silver atom can be considered to be an atomic sized particle of metallic silver. It is
the smallest size of silver matter that exists. The diameter of a single silver atom is 0.288
nm. While it is theoretically possible to have a particle of metallic silver that consists of a
single atom, in practice particles are much larger and consist of many atoms. Just for
reference, a particle one nanometer in diameter would consist of 31 silver atoms, and a 5 nm
diameter particle would be about 3900 atoms while a 20 nm diameter particle would contain
about 250,000 silver atoms. The particle size typically observed in colloidal silver has been
measured in the range of 5 to 200 nanometers. Such measurements are performed using a
Photon Correlation Spectrometer (PCS) that can measure down to 1 nm.
A silver ion is a single atom of silver that is missing one electron from its outer orbit. The
diameter of a silver ion is 0.230 nm, which is slightly smaller than an atom owing to one less
electron. Ag has the electron configuration [Kr]4d105s1. When Ag – e ? Ag+, it is the 5s1
electron which is lost. The missing electron causes the ion to be positively charged and also
changes the physical properties in some very dramatic ways. Metallic silver is not soluble in
water, but ionic silver has a finite measurable solubility. Typically, silver is dissolved in an
acid such as nitric acid to form silver nitrate. When silver is dissolved, it is no longer metallic
silver. It is not visible even under the most powerful microscope and it does not reflect light.
Even a solution saturated with Ag+ ions has no Tyndall effect 3, but a colloidal Ag does, even
in concentrations as little as 0.1 ppm. The solubility product constant, Ksp for AgOH is 1.52 x
10-8, which means that, in a neutral solution, one could have 9.2 x 1022 Ag ions per liter
without getting precipitation.
In summary, a silver ion is positively charged because it lacks an electron. An electron has a
negative charge. Take away an electron and the ion so formed assumes a positive charge.
The charge attributed to ions is ionic charge and it is due to the gain or loss of electrons. This
is not the same as a particle that may have a charge. Particle charge is due the adsorption of
charged species. In fact the silver particles found in colloidal silver are negatively charged,
not positive like the ions.
Silver particles that are suspended in pure water to form a colloid will assume a negative
charge that is called the zeta potential. Most solids develop a negative zeta potential when
dispersed in water of low ionic concentration. The charge acquired by the particles is partly
due to the adsorption of ions in the solution. The surface charge gives rise to a potential
distribution around the particle: the value of this potential at the slipping plane 4 is defined
as the zeta potential.
The zeta potential of colloidal silver solutions that contain silver ions will typically be in the
range of –35 to –45 millivolts (mV) depending on ionic content. The zeta potential of silver
colloids that contain no silver ions will have a higher negative potential of about –50 mV. The
higher the ionic content, the less negative the zeta potential since the positive charge of the
silver ions will cancel some of the negative charge on the particles.
Particles have a negative charge
In the case of colloidal silver, the silver ions present are positively charged, so how do the
silver particles acquire a negative charge? Silver ions are created during the electrolysis that
makes colloidal silver. The creation of silver ions would tend to make the net charge of the
solution positive. However, solutions always have a net charge very close to zero because
Coulomb force is extremely strong, and even a tiny charge imbalance creates enough voltage
to ionize everything in-between and cancel it. Ionization breaks the water molecule into
hydrogen H+ and hydroxyl ions OH-, which are negatively charged. The negative charge of
the hydroxyl ions counters the positive charge of the silver ions and maintains a solution of
whose net charge is zero. Thus the negative hydroxyl ions are created at the same time that
the positive silver ions and silver particles are created. The hydroxyl ions are non-metallic
ions that bond to the atoms of the silver particles thus imparting their negative charge to
Oxygen has 6 valence electrons and 2 hydrogens have one each, for a total of 8. Therefore
the Lewis structure of H2O is
This is known as AX4E2 structure (4 electron clouds, 2 unshared pairs) which would be bent,
with a bond angle of 107 degree.
The actual bond angle is 105 degree , due to the repulsion of the 2 unshared pairs.
When H ionizes as H+, that leaves the non-metallic OH- anion , which would have the
following structure and would be polar
As in the case of sols, when the OH- anion approaches the Ag atom, although that atom is
neutral, the first thing it sees is the 5s1 electron, therefore, the H, or positive, end of the
anion is attracted to the atom, leaving the negative end sticking out into the solution. This
behavior is well documented for sols (colloidal particles which have charged particles
adsorbed on them). The mutual repulsion of the similar charges then stabilizes the colloid by
keeping the particles from agglomerating.
Why are the positive silver ions not attracted to the negative hydroxyl ions?
The force of attraction or repulsion of electric charges is inversely proportional to the
dielectric constant of the medium surrounding the charges. Water has a very high dielectric
constant of about 80 at room temperature. This means that the two opposite electric charges
in water attract each other with a force only 1/80 as strong as in air or a vacuum. Thermal
agitation of the ions is great enough to cause the ions to dissociate. It is common that ions of
opposite charge coexist in solution. For example, when salt is dissolved in water the resulting
solution contains sodium ions (Na+) and chloride ions (Cl-) of opposite charge.
Silver colloids must contain suspended particles of silver and usually also contain dissolved
silver ions. Solutions that contain only dissolved silver ions are not colloids. High quality
colloids contain a high percentage of silver particles. Ideally, a silver colloid would contain no
Silver ions are positively charged and silver particles in colloidal suspension are negatively
charged. Reducing ionic silver content causes the zeta potential to become more negative
increasing the stability of the colloid.
4. Colloidal Silver versus Bacteria and Viruses.
What is colloidal silver?
Colloidal Silver is a solution of extremely fine sub microscopic particles (.015 - .005 microns)
of pure silver suspended in water by a positive electric charge on each particle. The particles
remain suspended throughout the solution because these positive charged particles repel
each other with a greater force than gravity can exert upon. A powerful germicidal, silver is
an exceptional metal in that it is non-toxic to the human body, but lethal to over 650 disease
causing bacteria, viruses, fungi, parasites, and molds; while conventional pharmaceutical
antibiotics are typically effective against only 6 or 7 types of bacteria. Some new strains of
bacteria classified as MDR (Multiple Drug Resistant) have proven to be resistant to all
pharmaceutical antibiotics, but not to colloidal silver due to different germicidal mechanisms
How does colloidal silver work?
Richard Davies and Samuel Etris of The Silver Institute, in a 1996 monograph entitled The
Development and Functions of Silver in Water Purification and Disease Control, discuss three
mechanisms of deactivation that silver utilizes to incapacitate disease causing organisms.
They are Catalytic Oxidation, Reaction with Cell Membranes, and Binding with the DNA of
disease organisms to prevent unwinding.
Silver, in its atomic state, has the capacity to absorb oxygen and act as a catalyst to bring
about oxidation. Atomic (nascent) oxygen absorbed onto the surface of silver ions in solution
will readily react with the sulfhydryl (-S-H) groups surrounding the surface of bacteria or
viruses to remove the hydrogen atoms (as water), causing the sulfur atoms to form an R-S-
S-R bond; blocking respiration and causing the bacteria to expire. Employing a simple
catalytic reduction/oxidation reaction, colloidal silver will react with any negative charge
presented by the organism's transport or membrane proteins and deactivate them.
Reaction with Bacterial Cell Membranes:
There is evidence that silver ions attach to membrane surface radicals of bacteria, impairing
cell respiration and blocking its energy transfer system. One explanation is based on the
nature of enzyme construction: Specific enzymes are required for a given biochemical
activity to take place. Enzyme molecules usually require a specific metallic atom as part of
the molecular matrix in order to function. A metal of higher valance can replace a metal of
lower valance in the enzyme complex, preventing the enzyme from functioning normally.
Silver, with a valance of plus 2, can replace many metals with a lower, or equal valance that
exhibit weaker atomic bonding properties.
Binding with DNA:
Studies by C.L. Fox and S.M. Modak with Pseudomonas aeruginosa, a tenacious bacteria that
is difficult to treat, demonstrated that as much as 12% of silver is taken up by the organism's
DNA. While it remains unclear exactly how the silver binds to the DNA without destroying
the hydrogen bonds holding the lattice together, it nevertheless prevents the DNA from
unwinding, an essential step for cellular replication to occur.