nano robotics as medicament

Nanorobotics as medicament

Table of Contents

1. INTRODUCTION....................................................................................................2

2. HOW PHARMACEUTICAL COMPANY DEVELOPS DRUGS.........................4

3. NANOROBOTS: WHAT ARE THEY?..................................................................5

4. PRINCIPLES OF NANOROBOTIC APPLICATIONS........................................6

5. APPLICATIONS OF NANOROBOTS IN MEDICAL FIELD..............................7

5.1 IMPROVING OXYGEN DELIVERY.......................................................7

5.1.1 DESIGN ISSUES OF RESPIROCYTE.............................................8

5.2 HEART ATTACKS....................................................................................9

5.2.1 NANOROBOTS IN HEART SURGERY...................................9

5.2.2 MOLECULAR SORTING ROTORS.........................................10

5.2.3 PROPELLOR..............................................................................10

5.2.4 INJECTION OF NANOROBOTS..............................................10

5.2.5 NAVIGATION............................................................................11

5.2.6 POSITIONING............................................................................12

5.2.7 DETECTION..............................................................................12

5.2.8 DESTRUCTION.........................................................................12

5.3 AN IDEAL NANOROBOTIC PHARMACEUTICAL DELIVERY

VEHICLE..................................................................................................13

5.3.1 COOKING CANCER WITH NANOSHELLS...........................15

5.3.2 CONTROL OF CELL SIGNALING PROCESSES...................18

5.4 REPLACING JOINTS WITH BETTER STUFF......................................20

5.5 HOW DOES A NANOROBOT DETECT A CEREBRAL

ANEURYSM? ..............................................................................................

.....................22

6. MANUFACTURING DESIGN.............................................................................24

7. FEW INTERESTING FACTS ABOUT NANOROBOTS....................................25

CONCLUSION........................................................................................................................28

GOVT.S.K.S.J.T.IE.C.DEPT Page 0


REFERENCES.........................................................................................................................29

ABSTRACT

The path we have chosen is the union of robotics & medicine. The integration of

nanotechnology into medicine is likely to bring some new challenges in medical treatment.

The proposed application of nanorobots can range from common cold to dreadful disease

like cancer. Some such examples can be Pharmacyte, Respirocyte, Microbivores,

Chromallocyte and many more. The study of nanorobots has lead to the field of

Nanomedicine. Nanomedicine offers the prospect of powerful new tools for the treatment of

human diseases and the improvement of human biological systems.

Let us peep inside the real world of NANOTECHNOLOGY.

Advancement in nanotechnology may allow us to build artificial red blood cells called

Respirocytes capable of carrying oxygen and carbon dioxide molecules (i.e., functions of

natural blood cells). Respirocytes are nanorobots, tiny mechanical devices designed to

operate on the molecular level. Respirocytes can provide a temporary replacement for natural

blood cells in the case of an emergency. Thus Respirocytes will literally change

the treatment of heart disease. One of the most realistic and nearly feasible achievements is

the cure for cancer which is one of the main focuses of this work. From eliminating the side

effects of chemotherapy to treating Alzheimer's disease, the potential medical applications

of nanorobots are vast and ambitious. A few generations from now someone diagnosed

with cancer will be offered a new alternative to chemotherapy. The traditional treatment of

radiation that kills not just cancer cells but healthy human cells as well, causing hair loss,

fatigue, nausea, depression, and a host of other symptoms. A doctor practicing Nanomedicine

would offer the patient an injection of a special type of Nanorobot that would seek out

cancer cells and destroy them, dispelling the disease at the source, leaving healthy cells

untouched. The extent of the hardship to the patient would essentially be a prick to the arm. A

person undergoing a nanorobotictreatment could expect to have no awareness of the

molecular devices working inside them, other than rapid betterment of their health.

These nanorobots will be able to repair tissues, clean blood vessels and airways, transform

our physiological capabilities, and even potentially counteract the aging process. The

researchers think their nanorobots could become available around 2015. If this medicine



delivery comes into existence, then there will be no end for our human life. In this paper we

are dealing with nanorobotics.

CHAPTER 1

INTRODUCTION:

In the 1966 film fantastic voyage, audiences were introduced to their own bodies from the

inside. A group of doctors got into a submarine-like ship and were shrunk down to the size of

a cell. They were then injected into a human body to search and destroy a blood clot.

Audiences got a fairly realistic look at some of the inner working of the human body.

It’s a recurrent theme in science fiction: human beings want to live long, healthy, pain-free

lives and we will continue to create (and invest in) ways to do so. Nanotechnology is an

emerging reality that can help us along that path. It won’t enable humans to shrink , but it

can, however, help us modify and create particles that circulate through the body with as

much control as if we were in there calling the shots.

Nanotechnology is a fascinating science and it offers many challenges. One such challenge

is Nanorobots, which once thought to be a fantasy has come into reality now. Nanorobotics

is the emerging technology field of creating machines or robots whose components are at or

close to the microscopic scale of a nanometer (10−9 meters). More specifically, nanorobotics

refers to the nanotechnology engineering discipline of designing and building nanorobots,

with devices ranging in size from 0.1-10 micrometers and constructed of nanoscale or

molecular components. The names nanobots, nanoids, nanites, nanomachines or

nanomites have also been used to describe these devices currently under research and

development.

The present era of nanotechnology has reached to a stage where programmable and externally

controllable complex machines that are built at molecular level which can work inside the

patient’s body. Nanotechnology will enable engineers to construct sophisticated nanorobots

that can navigate the human body, transport important molecules, manipulate microscopic

objects and communicate with physicians by way of miniature sensors, motors, manipulators,

power generators and molecular- scale computers. The idea to build a nanorobots comes from

the fact that the body’s natural nanodevices; the neutrophiles, lymphocytes and white blood



cells constantly rove about the body, repairing damaged tissues, attacking and eating invading

microorganisms, and sweeping up foreign particles for various organ to break down or

excrete. Nanomedical systems designed to perform a specific task with precision at nanoscale

dimension. This allows drugs of nanosize to be used in lower concentration and has an earlier

onset of therapeutic action. It also provides materials for controlled drug delivery by directing

carriers to a specific location. The typical medical nanodevice will probably be a micron-

scale robot assembled from nanoscale parts. These nanorobots can work together in response

to environment stimuli and programmed principles to produce macro scale results.

This chapter explores some unique approaches to delivering drugs and killing cancer that

nanotechnology makes possible. We start with problems pharmaceutical companies have

with drug development and discuss a “nano-way” to deliver drugs that addresses this

problem. We then provide a recipe for eliminating cancer and tell you about some new

concepts of artificial blood and bones.



CHAPTER 2

HOW PHARMACEUTICAL COMPANY DEVELOPS

DRUGS

Bioavailability refers to how well a treatment can target specific cells. For the last hundred

years or so, pharmaceutical products have suffered from poor bioavailability their main

approach is to flood the body with drugs that are needed. One aspirin cures a headache but

one hundred aspirins kill the patient. This is especially not good for cancer and

chemotherapy; increasing the amount of toxic drugs eventually kills the patient.

As with any business, companies doing drug development have to choose between risk and

reward. The amount of risk in drug development is incredibly high in terms of both times and

money. The starting point is to determine which molecules of what compounds will be most

effective at curing a disease. Different programs speed up the process but taking a new drug

from research to development to administration still takes a long time. Even today, the

average time between the patent application and marketing of a new medicine is 12 years.

And a patent expires after only 20 years. To top it off, some research projects are scrapped as

late as advanced stage clinical trials (roughly nine years after kickoff!).

Only 32 new drugs were introduced in 2000 a pretty low figure and the number of new drugs

is increasing. This is not good trade-off, but there may be some light at the end of particular

tunnel: Rapid advances in biotechnological applications can help us in the direction of faster,

less-costly drug development. Nanotechnology, in conjunction with biotechnology, will aid

in more effective medicines while lowering the costs.



CHAPTER 3

NANOROBOTS: WHAT ARE THEY?

Nanorobots are nanodevices that will be used for the purpose of maintaining and protecting

the human body against pathogens. They will have a diameter of about 0.5 to 3 microns and

will be constructed out of parts with dimensions in the range of 1 to 100 nanometers. The

main element used will be carbon in the form of diamond / fullerene nanocomposites because

of the strength and chemical inertness of these forms. Many other light elements such as

oxygen and nitrogen can be used for special purposes. To avoid being attacked by the host’s

immune system, the best choice for the exterior coating is a passive diamond coating, The

smoother and more flawless the coating, the less the reaction from the body’s immune

system. Such devices have been designed in recent years but no working model has been built

so far.

The powering of the nanorobots can be done by metabolising local glucose and oxygen for

energy. In a clinical environment, another option would be externally supplied acoustic

energy. Other sources of energy within the body can also be used to supply the necessary

energy for the devices. They will have simple onboard computers capable of performing

around 1000 or fewer computations per second. This is because their computing needs are

simple. Communication with the device can be achieved by broadcast-type acoustic

signalling.

A navigational network may be installed in the body, with station keeping navigational

elements providing high positional accuracy to all passing nanorobots that interrogate them,

wanting to know their location. This will enable the physician to keep track of the various

devices in the body. These nanorobots will be able to distinguish between different cell types

by checking their surface antigens (they are different for each type of cell). This is

accomplished by the use of chemotactic sensors keyed to the specific antigens on the target

cells.



When the task of the nanorobots is completed, they can be retrieved by allowing them to

exfuse themselves via the usual human excretory channels. They can also be removed by

active scavenger systems. This feature is design-dependent.

CHAPTER 4

PRINCIPLES OF NANOROBOTIC APPLICATIONS

The availability of advanced nanomedical instrumentalities should not significantly alter the

classical medical treatment methodology, although the patient experiences and outcomes will

be greatly improved. Treatment in the nanomedical era will become faster and more accurate,

efficient and effective.

Three key required pieces to advance the development and implementation of medical

nanorobotics, according to the paper published by The International Journal of Robotics

Research:

1. Equipment prototyping: Computational nanotechnology provides a key tool for the

fast and effective development of nanorobots, helping in the investigation to address

major aspects on medical instrumentation and device prototyping.

2. The manufacturing technology: For manufacturing purposes, the nanorobot should be

integrated as a biochip device.

3. Inside-body transduction: Cell morphology, microbiology, and proteomics are used

as parameters for nanorobot morphology and inside-body interaction. Changes on

chemical gradients and telemetric instrumentation are used for medical prognosis, with

the nanorobots activation based on proteomic over expression.



CHAPTER 5

APPLICATIONS OF NANOROBOTS IN MEDICAL

FIELD

5.1IMPROVING OXYGEN DELIVERY

The artificial mechanical red blood cell or “respirocyte” is a bloodborne spherical 1-micron

diamondoid 1000- atmosphere pressure vessel (Fig1) with active pumping powered by

endogenous serum glucose, able to deliver 236 times more oxygen to the tissues per unit

volume than natural red cells and to manage carbonic acidity. The nanorobot is made of 18

billion atoms precisely arranged in a diamondoid pressure tank that can be pumped full of up

to 3 billion oxygen (O2) and carbon dioxide (CO2) molecules. Later on, these gases can be

released from the tank in a controlled manner using the same molecular pumps. Respirocytes

mimic the action of the natural hemoglobin-filled red blood cells. Gas concentration sensors

on the outside of each device let the nanorobot know when it is time to load O2 and unload

CO2 (at the lungs), or vice versa (at the tissues). An onboard nanocomputer and numerous


Figure 1 An artificial red cell—the respirocyte.285 Designer Robert A.Freitas, Jr.© 1999, Forrest Bishop.Used with permission.


chemical and pressure sensors enable complex device behaviors remotely reprogrammable by

the physician via externally applied acoustic signals.

5.1.1 DESIGN ISSUES OF RESPIROCYTE

Figure 2 respirocyte design

The respirocyte is built of 18 billion precisely arranged structural atoms. It is constructed of

diamondoid honeycomb framework for maximum strength. Thick diamond bulkheads

separate internal tankage volumes. Twelve pumping stations are spaced evenly along an

equatorial circle. Respirocytes exchange gasses via molecular sorting rotors. The rotors have

specially shaped tips to catch particular types of molecules Gas molecules are stored tightly

in tanks. Each respirocyte has three types of rotors. One gathers oxygen at the lungs or in

production before introduction to the body and releases it while traveling through the body.

Another captures carbon dioxide while in the bloodstream and releases it at the lungs. The

third takes in glucose from the bloodstream, which is burned in a reaction similar to cellular

respiration in order to power the respirocyte. Anonboard hemomechanical turbine or fuel cell

generates power by combining glucose drawn from the bloodstream and oxygen drawn from

internal storage.. Each power plant develops 0.3 Pico watts of power. One power plant



measures 42 nm x 42 nm x 175 nm in size, constructed of 100 million atoms weighing ~10-

18 kg. Various sensors are needed to acquire the external data essential in regulating gas

input and output operations, tank volume management, and unique protocols. One example is

constructing a concentration sensor from a sorting rotor. The respirocyte would probably

need only about 1000 operations per second.

5.2 HEART ATTACK

Blood vessels play an important role in supply a blood to all parts of the body. Due to the

fatty deposition on the walls of blood vessels blood will not move freely to all parts of the

body these leads to heart attacks and damage the vital organs.

In general the most common methods of surgery used for heart attacks is

1. By-Pass surgery

2. Angio Plaster

5.2.1 NANOROBOTS IN HEART SURGERY

Both of the above methods are risky and number of side effects. As a result patient becomes

very weak. But a surgery-using nanorobot is very simple one. Doctors do their treatment even

without touching the body.

Below figure 3 shows the structure of the nanorobots. It is constructed with various

nanomechanical devices and nanosensors like.


Figure 3 Structure of Nanorobots

http://i.zdnet.com/blogs/nanorobots_sensors.jpg


· Molecular sorting rotors

· Propeller

· Fins

· Sensors

Types of Sensors

1. Chemical sensors -> to find the fatty deposit.

2. Microwave generated sensing -> to generate movement.

3. Chemotactic sensors -> to find cancer cells.

4. Acoustic sensors-> to guide the nanorobots

5.2.2 MOLECULAR SORTING ROTORS

It is made up of carbon nanotubes. Simply a sheet of carbon atom forms a carbon nanotube .

A roll having only one sheet of carbon atoms thickness is known as single walled carbon

nanotubes (SWNT). Thus the electrical properties of SWNT’s can be used to generate

mechanical motion from electrical energy. One of the main advantages of these SWNT’s is,

operating at the molecular level. Nanotube substitutes with nanogears with axle used for

changing the direction of movement.

5.2.3 PROPELLOR

The word propeller in ship is used to drive forward the device against water. Like that in

nanorobots it is used to drive forward against the blood stream. Fins are fitted along with the

propellers which are used to propel the device. Sensors are fitted externally and internally

with the nanorobots to receive the signal for correct guidance. There are several techniques to

do the heart surgery with the nanorobots. We have to know how to inject nanorobots into our

body, how to move it to the destination place, how to control and remove the device after

surgery.



5.2.4 INJECTION OF NANOROBOTS

We have to find a way to introduce nanorobots into the body for surgery and allowing it to do

the operation without ancillary damage. So nanorobots should be made smaller than the blood

vessels thus making it to travel. Femoral artery in the leg is considered to be the largest artery

in our body. So we inject the nanorobots through this artery.

5.2.5 NAVIGATION

Every living thing needs area to move. Like fishes are moved in water, nanorobots use blood

flow for its movement. It must be able to guide the device which makes use of the blood

flow. The devices used for navigation are propeller, fins, jet pump, and electromagnetic

pump. In order to move the nanorobots in blood flow, following things are very important

1. Speed of blood

2. Get through the heart without stuck

3. React with changes in blood flow rate

4. Able to change the direction according to the blood stream

To satisfy the above consideration we have to make the nanorobots with electric motors

turning propellers.

5.2.6 POSITIONING


Figure 4 Navigation of nanorobots into blood vessels


To know the location of nanorobots where it goes we use ultrasonic technique. Nanorobots

must be able to produce ultrasonic waves by passing a signal to piezoelectric membrane,

which is in built with the device. Several signals processing techniques are used to track this

ultrasonic signal and finding the location at any time. Instead of ultrasonic wave we use

infrared ray for signal processing.

5.2.7 DETECTION

To locate a blood clot (or) deposit of arterial plaque we use sensors of different types.

Already preplanned route is available to reach operation site. With the help of preplanned

route we reach the fatty deposited area. (NanoRobots towards a destination) To control the

nanorobots as per our wish, we fit the TV camera in the nanorobots and transmit its picture

outside the body to a remote control unit. Solid-state television camera sensors are used to

receive the signals from the remote station and do the operations according to signals send by

remote control unit. There are pre-programmed microchips available to give appropriate

signals so that nanorobots is initiated externally through a computer.

5.2.8 DESTRUCTION

The fatty deposits (or) clots are removed using special blades fitted with nanorobots.

Continuous (or) pulse signal is used to activate the blades. These blades physically separate

the deposits from blood vessels. Care should be taken in removing the fatty deposits. Small

deposits of these fatty materials without removing lead to big problem in future.

Production of power is very important for every operation to most efficient one in magnetic

induction. Our body is full of magnetic field. Rotation of nanorobots cuts this magnetic field,


Figure 5 View of Nanorobot removing the fatty deposit


produce power based on faraday’s law. To take nanorobots from the body we use two

methods one is retrace our path upstream another is making small surgery to remove.

5.2An Ideal Nanorobotic Pharmaceutical Delivery Vehicle

What would an ideal drug delivery vehicle look like? To start with, it would be targetable not

just to specific tissues or organs, but to individual cellular addresses within a tissue or organ.

Alternatively, it would be targetable to all individual cells within a given tissue or organ that

possessed a particular characteristic (e.g., all cancer cells, or all bacterial cells of a defined

species). This ideal vehicle would be biocompatible and virtually 100% reliable, with all drug

molecules being delivered only to the desired target cells and none being delivered elsewhere

so that unwanted side effects are eliminated. The ideal vehicle would remain under the

continuous control of the supervising physician, including post-administration. Even after the

vehicles had been injected into the body, the doctor would still be able to activate or

inactivate them remotely, or alter their mode of action or operational parameters. Once

treatment was completed, all of the vehicles could be removed intact from the body, leaving

no lingering evidence of their passage. This hypothetical ideal drug delivery vehicle may be

called a “Pharmacyte”

Pharmacytes will be self-powered, computer-controlled nanorobotic systems capable of

digitally precise transport, timing, and targeted delivery of pharmaceutical agents to specific

cellular and intracellular destinations within the human body. Drug molecules could be

purposely delivered to one cell, but not to an adjacent cell, in the same tissue. The exemplar

Pharmacyte would not be a relatively passive nanoparticle but rather would be an active

medical nanorobot 1–2 μm in size, similar to the respirocyte but slightly larger. It would be

capable of carrying up to ~1 μm3 of pharmaceutical payload stored in onboard tanks that are

mechanically offloaded using molecular sorting pumps mounted in the hull, operated under

the control of an onboard nanocomputer. Depending on mission requirements, the payload

could be discharged into the proximate extracellular fluid or delivered directly into the

cytosol using a transmembrane injector mechanism. The sorting pumps are typically

envisioned as ~1,000 nm3-size devices that can transfer ~106 molecules/sec. Each pump

employs reversible binding sites mounted on a rotating structure that cycle between the

interior and exterior of the nanorobot, allowing transport of a specific molecule even against

a considerable concentration gradient.



Other reversible binding sites comprise sensors on the surface of the nanorobot in order to

recognize the unique biochemical signature of specific vascular and cellular addresses,

simultaneously testing encountered biological surfaces for a sufficiently reliable combination

(at least 5–10 in number) of positive-pass and negative-pass molecular markers to ensure

virtually 100% targeting accuracy. Onboard power may be provided by glucose and oxygen

drawn from the local environment (e.g., circulating blood, interstitial fluid, or cytosol) that is

metabolized using fuel cells or other methods for biochemical energy conversion. If needed

for a particular application, deployable mechanical cilia and other locomotive systems can be

added to the Pharmacyte to permit transvascular and transcellular mobility, thus allowing

delivery of pharmaceutical molecules to specific cellular and even intracellular addresses

with negligible error. Because sorting pumps can be operated reversibly, Pharmacytes could

also be used to selectively extract specific molecules from targeted locations as well as

deposit them. Pharmacytes, once depleted of their payloads or having completed their

mission, would be recovered from the patient via centrifuge nanapheresis or by conventional

excretory pathways. The nanorobots might then be recharged, reprogrammed and recycled

for use in a subsequent patient who may need a different pharmaceutical agent targeted to

different tissues or cells than in the first patient.

Phagocytosis and foreign-body granulomatous reaction are major issues for all medical

nanorobots intended to remain in the body for extended durations, though short-duration

Pharmacytes that can quickly be extracted from the body may face somewhat fewer

difficulties. In either case, bloodborne 1 to 2 μm Pharmacytes can avoid clearance by the RES

(whether via geometrical trapping or phagocytic uptake) and techniques have been proposed

for phagocyte avoidance and escape at each step in the phagocytic process. Modest

concentrations of Pharmacytes will not embolize small blood vessels because the minimum

viable human capillary that allows passage of intact erythrocytes and white cells is 3 to 4 μm

in diameter, which is larger than the largest proposed Pharmacyte. Pharmacytes can also be

equipped with mobility systems to allow mechanically-assisted passage through partially

occluded vessels or unusually narrow spaces such as the interendothelial slits of the spleen.

Targeting ligands or receptors in the cell membrane exterior can be recognized by

chemotactic sensors on the nanorobot surface, but note that the Pharmacyte (as distinguished

from conventional nanoparticles) need not always be endocytosed. For example, in some

cases nanorobots may use transmembrane mechanical nanoinjectors to avoid having to enter

a target cell. Alternatively, if the mission requires cytopenetration then endocytosis of the

nanorobot may be purposely stimulated using biomimetic or completely artificial (including



powered mechanical) methods; after payload delivery, indigestible diamondoid nanorobots

will require exocytosis by similar means. Nanorobot volume is only 1 to 10 μm3 compared to

103 to 104 μm3 for most human tissue cells so Pharmacytes could be targeted to intracellular

organelles, though nanorobots would have insufficient room to enter one (excepting perhaps

the ER and nucleus) and would have to rely on nanoinjection in those cases.

There are many potential uses of Pharmacytes but it will suffice to briefly mention just two

general classes of applications.

5.2.1 COOKING CANCER WITH NANOSHELLS

The body is constantly replacing old cells with new ones; the old, damaged cells are

deliberately “killed” in a process called apoptosis. Sometimes, however, mutations occur so

that some new cells form when the body doesn’t need them and old cells don’t die when they

should –which, by the way, is a basic definition of cancer cells bypass apoptosis and form a

mass of tissue called a tumour.


Figure 6 tumour cell genaration


Pharmacyte is often desired to deliver cytocidal agents to tumor cells. Current methods

involve introducing large quantities of chemotherapy agents into the body in an effort to kill a

relatively few cancerous cells, with numerous unwanted side effects on healthy cells. Precise

targeting using Pharmacytes can ensure delivery only to the correct cellular addresses, with

presentation of cytocidal chemical agents literally on a cell-by-cell basis. In one trivial

scenario, the targeted killing of 1 billion cancer cells with each cell capable of being killed by

~106 precisely delivered ~1,000-dalton cytocidal molecules (i.e., lethality similar to bufagin

toxin) would require a total whole-body treatment dose of just ~1015 cytocidal molecules or

~0.001 mm3 (~2 μg) of delivered material. This dose could be carried and dispensed by one

trillion Pharmacyte nanorobots (total injected volume of therapeutic nanorobots ~2 cm3)

assuming that only 0.1% of the nanorobots encounter an acceptable target and are allowed to

release a 0.001 μm3 cytocidal payload into the targeted cell, while the remaining 99.9% of

the nanorobots release nothing. After initiating cell death, unmetabolized free cytocidal

molecules can be locally reacquired by the Pharmacyte and subsequently transported out of

the patient, thus minimizing any post-treatment collateral damage. Note that the strict size

requirements for macromolecules to reach the leaky vasculature of a tumor and convectively

enter its pores may apply to passively-diffusing payload molecules that might be conveyed

and released by Pharmacytes, but these limits do not apply to the motorized active nanorobots

themselves. Upon arriving in the vicinity of a tumor, the Pharmacyte may deliver its payload

either via direct nanoinjection (for tumor cells adjoining the vasculature) or by progressive

cytopenetration through adjacent cells until the targeted tumor cell that awaits payload

delivery is reached.


Figure 7 cancer treatment with nanorobots.


It is well-known that apoptotic cellular “death receptors” can be expressed on both normal

and cancerous cells in the human body, so one challenge for conventional drug-based therapy

is to find some way to activate death receptors selectively on cancer cells only. With

Pharmacytes, such selectivity should be simple and routine using multiple chemosensors, a

benefit that may be characteristic of most future nanorobot-based therapeutics. For example,

if caspase cascade amplification is sufficient to permit single-site activation of the cascade,

then in principle an extracellular nanorobot intending cytocide of a detected cancerous cell

could press onto the outer surface of the target cell an appropriate ligand display tool. This

tool might contain suitably exposed trimeric CD95L (aka FasL) ligand (binds to the

extracellular domains of three CD95 death receptors), TNF or lymphotoxin alpha (binds to

CD120a), Apo3L ligand aka TWEAK (binds to DR3), or Apo2L ligand. The binding event

would then activate a single death receptor complex, potentially triggering the entire

irreversible cytocidal cascade. If necessary, multiple such display tools could be employed.

This technique avoids much of the storage requirement for bulky consumables aboard the

medical nanorobot. As yet another approach, molecular sorting pumps on the pharmacyte

surface could be used to selectively extract from the cytoplasm of a target cell specific crucial

molecular species of inhibitors of apoptosis (IAPs) that normally hold the apoptotic process

in check. Examples include survivin, commonly found in human cancer cells, the

transcription factor NF-κB, and Akt, which delivers a survival signal that inhibits the

apoptosis induced by growth factor withdrawal in neurons, fibroblasts, and lymphoid cells.

Conversely, decoy receptors (DcRs) that compete with DR4 and DR5 for binding to Apo2L

could be saturated with intrinsically harmless but precisely engineered intracellular “chaff”

ligands. With IAPs removed or DcRs blockaded, apoptosis may be free to proceed.

Pharmacytes could also tag target cells with biochemical substances capable of triggering a

reaction by the body’s natural defensive or scavenging systems, a strategy called “phagocytic

flagging”. For example, novel recognition molecules are expressed on the surface of

apoptotic cells. In the case of T lymphocytes, one such molecule is phosphatidylserine, a lipid

that is normally restricted to the inner side of the plasma membrane but, after the induction of

apoptosis, appears on the outside. Cells bearing this molecule on their surface can then be

recognized and removed by phagocytic cells. Seeding the outer wall of a target cell with

phosphatidylserine or other molecules with similar action could activate phagocytic behavior

by natural macrophages that had mistakenly identified the target cell as apoptotic. Loading

the target cell membrane surface with B7 costimulator molecules also permits T-cell

recognition, allowing an immunologic response via the immunological synapse. These



tagging operations should work well against cells that have an apoptotic response that can be

triggered by cytotoxic T cells, such as human cancer cells and cysts.

5.2.2 control of cell signalling processes

A second major application area of pharmacytes would be the control of cell Signalling

processes. As a trivial example, Ca++ serves as an intracellular mediator in a wide variety of

cell responses including secretion, cell proliferation, neurotransmission, cellular metabolism

(when complexed to calmodulin), and signal cascade events that are regulated by calcium-

calmodulin-dependent protein kinases and adenylate cyclases. The concentration of free Ca+

+ in the extracellular fluid or in the cell’s internal calcium sequestering compartment (which

is loaded with a binding protein called calsequestrin) is ~10-3 ions/nm3. However, in the

cytosol, free Ca++ concentration varies from 6 × 10-8 ions/nm3 for a resting cell up to 3 x

10-6 ions/nm3 when the cell is activated by an extracellular signal; cytosolic levels >10-5

ions/nm3 may be toxic (e.g., via apoptosis). To transmit an artificial Ca++ activation signal to

a typical (20 μm)3 tissue cell in ~1 msec, a single pharmacyte stationed in the cytoplasm

must promptly raise the cytosolic ion count from 480,000 Ca++ ions to 24 million Ca++ ions.

This is a transfer rate of ~2.4 × 1010 ions/sec that may be accomplished using ~24,000 hull-

mounted molecular sorting pumps across a total nanorobot emission surface area of ~2.4

μm2. Onboard storage volume of ~1 μm3 can hold up to ~20 billion calcium atoms, enough

to transmit up to ~1,000 artificial Ca++ signals into the cell even assuming no reabsorption

and recycling of the ions.

Properly configured in cyto pharmacytes could also modify natural intracellular message

traffic according to preprogrammed rules or by following external commands issued by the

supervising physician. In the case of steroids and thyroid hormones, this may involve the

direct manipulation of the signaling molecules themselves (after they have passed through the

cell membrane) or their bound receptor complexes. However, most signaling molecules are

absorbed at the cell surface, initiating a signal cascade which may be modulated by

manipulating second-messenger molecules or other components of the in cyto signal cascade.

A few basic examples of signal modifying action involving cAMP would include:



Amplification A single epinephrine molecule received by a beta adrenergic receptor at a cell

surface transduces the activation of dozens of G-protein alpha subunits, each of which in turn

activates a single adenylate cyclase enzyme which cyclizes hundreds of ATP molecules into

cAMP molecules. The intracellular population of cAMP (in muscle or liver target cells) is

normally <10-6Mor ~5 million molecules for a typical (20 μm)3 tissue cell. Stimulation by

epinephrine raises the cAMP population to ~25 million molecules in a few seconds.

However, upon detecting this rising tide of cAMP during the first few msec, each in cyto

pharmacyte could quickly amplify this existing chemical signal by releasing 20 million

cAMP molecules (occupying a storage volume of ~0.01 ìm3) from onboard inventories in ~1

msec—thus accelerating cellular response time by several orders of magnitude. Suppression.

Similarly, upon detection of rising cAMP levels in target cells, resident pharmacytes could

use molecular pumps to rapidly remove cAMP from the cytosol as quickly as it is formed,

even under maximum adrenal stimulation. The diffusion-limited intake current at the basal

concentration (~6 x 10-7 molecules/nm3) for a cAMP-absorbing spherical nanodevice 1 μm

in radius is ~4 million molecules/ sec, so a single such device could probably keep up with

natural cAMP production rates and thus completely extinguish the response by preserving a

flat basal concentration even in the face of a maximum stimulus. (As a practical matter, it

may be more efficient to control epinephrine generation at its glandular source unless it is

desired to interface with just a single tissue type.) Simultaneously, the cAMPabsorbing

nanorobot may hydrolyze the stored cAMP in the manner of the cAMP phosphodiesterases,

then excrete these deactivated AMP messenger molecules back into the cytosol. Similar

methods might be useful in ligand-gated ion channel desensitization or in disease symptom

suppression, as, for example, in suppressing the prolonged elevation of cAMP in intestinal

epithelial cells associated with the cholera toxin, which produces severe diarrhea by causing a

large influx of water into the gut.

Replacement Combining suppression and amplification, an existing chemical signal could be

eliminated and replaced by a different—even an opposite—message pathway using resident

pharmacyte mediators. Alternative pathways may be natural or wholly synthetic. Novel

responses to existing signals may be established within the cell to enhance functionality or to

improve stability or controllability. For instance, detection of one species of cytokine by a

pharmacyte could trigger rapid specific absorption of that cytokine and a simultaneous fast

release of another (different) species of cytokine in its place. Such procedures must of course

take into account the many redundant signaling pathways and backup systems (e.g.,

developmental signals, immune system, blood clotting) that exist within the body. Medical



nanorobots can allow the replacement of many redundant pathways with more refined and

specific responses.

Linkage Previously unlinked signal cascades may be artificially linked using in cyto

nanorobots. As a fanciful example, the receipt of epinephrine by pharmacytes located in the

capillaries of the brain could trigger these devices to suppress the adrenalin response while

simultaneously releasing chemical messengers producing message cascades that stimulate

production of enkephalins or other opioids, thus encouraging a subjective state of

psychological relaxation rather than the “fight orflight” response to certain stressful

conditions.

5.3REPLACING JOINTS WITH BETTER STUFF

Bones are actually a sort of process: at the cellular level, they undergo constant repair and

rebuilding as they fight gravity, allowing our body to effectively adapt to our environment.

What makes bone to versatile is its basic building material; hydroxyapatite. Osteoblasts

secrete this stuff within a matrix of collagen. The body continuously reabsorbs the

hydroxvapatite crystals and re-deposits new material in their place what process does is

adjust the bone`s thickness in response to changes in the body `s distribution of weight figure

shows an excellent top –down hierarchy of strength in the materials that make up bone

comparing actual bone cells to collagen fibers and to individual collagen molecules [ each a

mere3nm in length]


Figure 8 scales of bone structure.


Why is the bone being reabsorbed? Well, the body figures the bone isn’t needed. Since the

implant is now bearing the greatest amount of load, the body responds by “pulling back” on

bone production in that area. Just as the osteoblasts are stimulated into generating more bone

when they’re confronted by more stresses, they can also be told to back off when the burden

seems to be less. Result: bone generations falls off, and then the body starts to reabsorb

existing bone. The problem is how to keep the bone in the business of rebuilding itself.

Looking specifically at hip implants, another source of contention is the plastic that is used in

the socket portion. A traditional hip implant has a metal ball and a plastic socket, as shown in

fig. the metal rubs against the plastic socket, plastic particles break off, and the body responds

to foreign fragments with inflammation, resulting in bone loss at the femur. Researchers at

the Tokyo University are developing a biocompatible polymer joint that resembles

phospholipids. Using such a polymer joint fools the body into not attacking the residual

flakes; no inflammatory response means no weakening of the bone.

Bioactive materials have the ability to interact with living tissue and are the most promising

approach to ensuring a strong, long lasting adhesive interface between the implant and the

surrounding tissue. Now they have come up with a process that involves injecting the

affected joint with a soft material that then hardens at the molecular level, bonding a damaged

bone together. More specifically, the material reacts to body fluids to form apatite, the body’s

own ceramic. The resulting material is better than the existing artificial bone material; it’s

strong and hard as actual bone. Such a material is considered a “bioactive ceramic” the body

activates the material and helps form it into a ceramic. The approach combines various


Figure 9 hip implants


sophisticated understandings of materials, chemistry and biology at the molecular level,

which is what nanotechnology, is all about.

5.4HOW DOES A NANOROBOT DETECT A CEREBRAL

ANEURYSM?

A cerebral or brain aneurysm is a cerebrovascular disorder in which weakness in the wall

of a cerebral artery or vein causes a localizeddilation or ballooning of the blood vessel.

Aneurysms may result from congenital defects, preexisting conditions such as high blood

pressure and atherosclerosis (the buildup of fatty deposits in the arteries), or head trauma.

Cerebral aneurysms occur more commonly in adults than in children but they may occur at

any age.

Nanorobots used to detect brain aneurysm:

(a) the nanorobots enter the vessel and flow with the bloodstream (b) the nanorobots are

moving through the vessel with the fluid (c) the aneurysm saccular bulb begins to become

visible at the vessel wall (d) nanorobots move closer to the vessel deformation (e) mixed with

the plasma, NOS (nitric oxide synthase) signals can be detected as the chemical gradient

changes, denoting proteomic overexpression (f) the same workspace viewed without red

cells (g) the nanobiosensor is activated as the nanorobots move closer to the aneurysm,

emitting RF signals sent to the cell phone(h) as the nanorobots keep flowing, the chemical

signals become weaker, deactivating the nanorobot transmission (i) red cells and nanorobots

flow with the bloodstream until they leave the vessel.

Finally, here’s a key excerpt from the conclusion and outlook. “The nanomachine platform

design was based on clinical data, proteomic signals, cell morphology, and numerical


Figure 10 Nanorobots used to detect brain aneurysm

http://i.zdnet.com/blogs/nanorobot.jpg


analysis. For the proposed model, the nanorobots were able to recognize chemical gradient

changes in the bloodstream, retrieving information about the position inside the vessel as

intracranial aneurysm detection. An important and interesting aspect in the current

development is the fact that this platform, presented in terms of device prototyping and

system architecture integration, can also be useful for a broad range of applications in

medicine.”

CHAPTER 6:

MANUFACTURING DESIGN:



The approach taken in our development is called nanobhis (Nano-Build Hardware Integrated

System). It represents a joint set of well-established techniques and new methodologies from

nanotechnology with the aim of manufacturing nanorobots. The nanorobot must be equipped

with the necessary devices for monitoring the most important aspects of its operational

workspace. Depending on the case the temperature, Concentration of chemicals in the water,

and electrical conductivity, are some of relevant parameters when monitoring hydrological

resources. Geographically distributed teams of nanorobots are expected to open new

possibilities on agricultural and environmental applications with a larger spectrum of details

not seen whenever. For such aims, computing processing, energy supply, and data

transmission capabilities can be addressed through embedded integrated circuits, using

advances on technologies derived from VLSI design. CMOS VLSI design using deep

ultraviolet lithography provides high precision and a commercial massively way for

manufacturing nanodevices and nanoelectronics. The CMOS industry may thrive successfully

the pathway to enable nanorobots assembly, where the jointly use of nanophotonic and

nanotubes may even accelerate further the actual levels of resolution ranging from 248nm to

157nm devices. To validate designs and to achieve a successful implementation, the use of

VHDL has become the most common methodology utilized in the industry of integrated

circuits.

CHAPTER 7:

FEW INTERESTING FACTS ABOUT NANOROBOTS:

· What chemical elements would medical nanorobots be made of?



The typical medical nanodevice is made up of micronscale robot assembled from nanoscale

parts. These parts could range in size from 1-100 nm (1 nm = 10-9 meter), and might be fitted

together to make a working machine measuring perhaps 0.5-3 microns (1 micron = 10-6

meter) in diameter. Three microns is about the maximum size for blood borne medical

nanorobots, due to the capillary passage requirement.

· Could human body fluids get inside the nanorobot?

From a medical standpoint, it makes sense to regard the nanorobot as having two spaces,

which should be considered separately its interior and its exterior. It is true that the nanorobot

exterior will be exposed to the diverse chemical brew that makes up our human biochemistry.

But the interior of the nanorobot may be a highly controlled environment, possibly a vacuum,

into which external liquids cannot normally intrude. Of course it may often be necessary for a

nanorobot to import external fluids in a controlled manner for chemical analysis or other

purposes. But the important thing is that the device will be watertight and airtight. Body

fluids cannot get into the interior of the device, unless these fluids are purposely pumped in

for some specific reason.

· How would the nanorobots be retrieved from the body?

Some nanodevices4 will be able to exfuse themselves from the body via the usual human

excretory channels; others will be designed to allow ready exfusion by medical personnel

using apheresis-like processes (commonly called nanapheresis) or active scavenger systems.

It is very design dependent. In the case of the respirocytes, the removal procedure is fairly

simple: "Once a therapeutic purpose is completed, it may be desirable to extract artificial

devices from circulation. Onboard water ballast control is extremely useful during respirocyte

exfusion from the blood. Blood to be cleared may be passed from the patient to a specialized

centrifugation apparatus where acoustic transmitters command respirocytes to establish

neutral buoyancy. No other solid blood component can maintain exact neutral buoyancy,

hence those other components precipitate outward during gentle centrifugation and are drawn

off and added back to filtered plasma on the other side of the apparatus. Meanwhile, after a

period of centrifugation, the plasma, containing mostly suspended respirocytes but few other

solids, is drawn off through a 1-micron filter, removing the respirocytes. Filtered plasma is

recombined with centrifuged solid components and returned undamaged to the patient's body.

The rate of separation is further enhanced either by commanding respirocytes to empty all



tanks, lowering net density to 66% of blood plasma density, or by commanding respirocytes

to blow a 5-micron O2 gas bubble to which the device may adhere via surface tension,

allowing it to rise at 45 mm/hour under normal gravitational acceleration."

· How fast can medical nanorobots replicate inside the human body?

This is a very common error. Medical nanorobots need not EVER replicate. In fact, it is

unlikely that the FDA (or its future equivalent) would ever approve for general use a medical

nanodevice that was capable of in vivo replication. Except in the most unusual of

circumstances, you would never want anything that could replicate itself to be turned loose

inside your body. Replicating bacteria are trouble enough!

Replication is a crucial basic capability for molecular manufacturing. But aside from the most

aggressive applications, there is simply no good reason to risk manufacturing "fertile"

nanorobots inside the human body, when "mule" nanorobots can be manufactured so cheaply,

conveniently, and in such vast numbers outside of the human body. Replicators will almost

certainly be very tightly regulated by governments everywhere.

· Will medical nanorobots possess a humanlike artificial intelligence?

This is another common error. Many medical nanorobots will have very simple computers on

board each device. Respirocytes, for example, have only a ~1,000 operations/sec computer on

board each device far less computing power.

· How would you communicate with the machines as they do their work?

One of the simplest ways to send broadcast-type messages into the body, to be received by in

vivo nanorobots, is acoustic messaging. A device similar to an ultrasound probe would

encode messages on acoustic carrier waves at frequencies between 1-10 MHz. Thus the

supervising physician can easily send new commands or parameters to nanorobots already at

work inside the body. Each nanorobot has its own power supply, computer, and sensorium,

thus can receive the physician's messages via acoustic sensors, then compute and implement

the appropriate response. The other half of the process is getting messages back out of the

body, from the working nanodevices out to the physician. This can also be done acoustically.

However, onboard power requirements for micron-scale acoustic wave generators in water



dictate a maximum practical transmission range of at most a few hundred microns for each

individual nanorobot. Therefore it is convenient to establish an internal communications

network that can collect local messages and pass them along to a central location, which the

physician can then monitor using sensitive ultrasound detectors to receive the messages. Such

a network can probably be deployed inside a patient in less than an hour, may involve up to

100 billion mobile nanorobotic network nodes, and may release at most 60 watts of waste

heat (less than the 100-watt human body basal rate) assuming a (worst case) full 100%

network duty cycle.

· What form of detection system would medical nanorobots use to

distinguish between differing cell types?

Each cell type has its own unique set of surface antigens. Other cell surface antigens indicate

the health status of the cell, the parent organ type, the species of the animal, and even the

identity of the individuala kind of biochemical Social Security Number.

Example: One very simple nanorobot that I designed a few years ago is the artificial

mechanical red cell, which I call a "respirocyte". The Respirocyte measures about 1 micron in

diameter and just floats along in the bloodstream. It is a spherical nanorobot made of 18

billion atoms. These atoms are mostly carbon atoms arranged as diamond in a porous lattice

structure inside the spherical shell. The respirocyte is essentially a tiny pressure tank that can

be pumped full of up to 9 billion oxygen (O2) and carbon dioxide (CO2) molecules. Later on,

these gases can be released from the tiny tank in a controlled manner. The gases are stored

onboard at pressures up to about 1000 atmospheres. (Respirocytes can be rendered

completely non-flammable by constructing the device internally of sapphire, a flameproof

material with chemical and mechanical properties otherwise similar to diamond.)

CONCLUSION:

Nanotechnology provides the potential for reverse aging, curing physical diseases,

manufacture consumer goods at molecular level. As we have seen the wide application of

nanorobots in field of medicine, its advantages and usability makes it evolving technology in

the coming future. Not only in medicine but the magic of nanotechnology has spread in



various fields like information and communications, food resources, consumer goods,

chemistry and environment.

Nature has created nanostructures for billenia. Biological systems are an existing proof of

molecular nanotechnology. Rather than keep our eyes fixed on the far future, let us start now

by creating some actual working devices that will allow us to cure some of the most deadly

ailments known, as well as advance our capabilities directly, rather than as the side effects of

other technologies. There will be a day when eliminating cancer cells are mere an out patient

medical procedure.

REFERENCES:



1. Nanorobotics as medicament: (Perfect solution for cancer): Emerging Trends

in Robotics and Communication Technologies (INTERACT), 2010

International Conference. http://ieeexplore.ieee.org, IEEE CONFERENCES

2. Use of nanorobots in heart transplantation: Emerging Trends in Robotics and

Communication Technologies (INTERACT), 2010 International Conference.

http://ieeexplore.ieee.org, IEEE CONFERENCES

3. Nanorobots in cancer treatment: Emerging Trends in Robotics and

Communication Technologies (INTERACT), 2010 International Conference

on , http://ieeexplore.ieee.org, IEEE CONFERENCES

4. Nanotechnology: Book by Richard booker and earl boysen , wiley

publications USA, 2010 edition.

5. Nanotechnology : a gentle introduction to the next big idea by Mark A.

Ratner, Daniel Ratner

6. Introduction to Nanotechnology by Charles P. Poole, Jr., Charles P. Poole,

Frank J. Owens

7. Cancer-fighting technology (http:/ / www. physorg. com/ news116071209.

html)


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