Nanotechnology: Nanomedicine, role ofgold nanoparticles in cancerous cellsPresented byYashvant RaoCenter For NanoscienceCentral University of GujaratINDIAOctober 2012 Central University of Gujarat INDIA382030
NanotechnologyNanoscience is the study of atoms, molecules, andobjects whose size is on the nanometer scale ( 1 - 100nanometers ).nanotechnology works with materials, devices, andother structures.With a potential applications, nanotechnology is akey technology for the future and governmentshave invested billions of dollars in its research.Nanotechnology entails the application of fields ofscience as diverse as surface science, organicchemistry, molecular biology, semiconductorphysics, microfabrication etc.
Nanotechnology is the engineering of functionalsystems at the molecular scale.Nano refers to the 10-9 power, or one billionth. Inthese terms it refers to a meter, or ananometer, which is on the scale of atomicdiameters. For comparison, a human hair is about100,000 nanometers thick.The word itself is a combination of nano, from theGreek “nanos” (or Latin “nanus”), meaning“Dwarf”, and the word "Science”.By comparison, typical carbon-carbon bondlength, or the spacing between these atoms in amolucule, are in the range 0.12–0.15 nm, and a DNAdouble-helix has a diameter around 2 nm.Cont.
• Nanomedicine ranges from the medicalapplications of nanomaterials, to nanoelectronic,biosensors, and even possible future applications ofmolecular nanotechnology.• Nanomedicine seeks to deliver a valuable set ofresearch tools and clinically useful devices in thenear future• Two forms of nanomedicine that have already beentested in mice and are awaiting human trials areusing gold nanoshells to help diagnose and treatcancer, and using liposomes as vaccine adjuvantsand as vehicles for drug transport.
• The use of nanotechnology in medicine offerssome exciting possibilities. Some techniques areonly imagined, while others are at various stagesof testing, or actually being used today.• The use of nanotechnology in the field of medicinecould revolutionize the way we detect and treatdamage to the human body and disease in thefuture, and many techniques only imagined a fewyears ago are making remarkable progresstowards becoming realities.• Nanoparticles that deliver chemotherapy drugsdirectly to cancer cells are under development
End goal of nanomedicine is improved diagnostics, treatmentand prevention of disease
Cancer is a class of diseases characterized by out-of-control cell growth. There are over 100 different types ofcancer, and each is classified by the type of cell that isinitially affected. Cancer harms the body when damaged cells divideuncontrollably to form lumps or masses of tissue calledtumors. Tumors can grow and interfere with the digestive,nervous, and circulatory systems, and they can releasehormones that alter body function. Tumors that stay inone spot and demonstrate limited growth are generallyconsidered to be benignCancer
• A cancerous cell manages to move throughout thebody using the blood or lymph systems, destroyinghealthy tissue in a process called invasion.• That cell manages to divide and grow, making newblood vessels to feed itself in a process calledangiogenesis.• Tumer cells are besically two types.• A tumor cell is part of a tissue that is abnormallygrowing. It may be either malignant or benign innature. "Tumor" originally meant "swelling" because,with unchecked cellular reproduction, the tissueaffected swells to sometimes grotesque proportions.
While normal cells will stop dividing if there is a mutation inthe DNA, cancer cells will continue to divide with mutation.
When cancer begins it invariably produces nosymptoms with signs and symptoms only appearingas the mass continues to grow or ulcerates. For example mass effects from lung cancer can causeblockage of the bronchous resulting in cough orpneumonia, esophageal cancer can cause narrowingof the esophagus making it difficult or painful toswallow, and colorectal cancer may lead tonarrowing or blockages in the bowel resulting inchanges in bowel habits.Cont.
DNA mutations disrupt the cellcycle.Mutations may becaused by:1. radiation2. smoking3. Pollutants4. chemicals5. viruses
Cancer Screening and DiagnosisEarly and accurate diagnosis of cancer is importantto maximize the chances that a cancer can be cured
There are several factors that regulate the cellcycle and assure a cell divides correctly.1.Before a cell divides, theDNA is checked tomake sure it hasreplicated correctly. (IfDNA does not copyitself correctly, a genemutation occurs.DNA replicationanimation:click on DNA picture
Cancer is a disease of the cell cycle. Some ofthe body’s cells divide uncontrollably andtumors form.Tumors in Liver Tumor in Colon
Due to DNA mutations, cancer cells ignore thechemical signals that start and stop the cell cycle.
SUMMARYNormal Cell Division1. DNA is replicatedproperly.2. Chemical signals startand stop the cell cycle.3. Cells communicate witheach other so theydon’t becomeovercrowded.Cancer Cells1. Mutations occur in theDNA when it isreplicated.2. Chemical signals that startand stop the cell cycle areignored.3. Cells do not communicatewith each other andtumors form.
Carcinoma (Gk. karkinos, or "crab", and -oma,"growth") is the medical term for the mostcommon type of cancer occurring in humans.carcinoma is a cancer that begins in a tissue thatlines the inner or outer surfaces of the body, andthat generally arises from cells originating in theendodermal or ectodermal germ layer duringembryogenesis.carcinoma is tumor tissue derived from putativeepithelial cells whose genome has becomealtered or damaged to such an extent that thecells become transformed, and begin to exhibitabnormal malignant propertiesCarcinoma
• A sarcoma (from the Greek sarx meaning "flesh") isa cancer that arises from transformed cells ofmesenchymal origin.• Malignant tumors made of cancerousbone, cartilage, fat, muscle, vascular, orhematopoietic tissues are, by definition, consideredsarcomas.• This is in contrast to a malignant tumor originatingfrom epithelial cells, which are termed carcinoma.• Sarcomas are quite rare. Commonmalignancies, such as breast, colon, and lungcancer, are almost always carcinoma.
• Lymphoma is a cancer of the lymphocytes, a type of cellthat forms part of the immune system.• Lymphoma is present as a solid tumor of lymphoid cells.Treatment might involve chemotherapy and in some casesradiotherapy and/or bone marrow transplantation, and canbe curable depending on the histology, type, and stage ofthe disease.• These malignant cells often originate in lymph nodes,presenting as an enlargement of the node (a tumor). It canalso affect other organs in which case it is referred to asextranodal lymphoma
Leukemia (American English) or leukaemia (BritishEnglish) (from the Greek leukos λευκός "white", andhaima "blood") is a type of cancer of the blood or bonemarrow characterized by an abnormal increase ofimmature white blood cells called "blasts". Leukemia is abroad term covering a spectrum of diseases. In turn, it ispart of the even broader group of diseases affecting theblood, bone marrow, and lymphoid system, which areall known as hematological neoplasms. Clinically and pathologically, leukemia is subdividedinto a variety of large groups. The first division isbetween its acute and chronic forms.Cont.
A germ cell tumor (GCT) is a neoplasm derived fromgerm cells. Germ cell tumors can be cancerous or non-cancerous tumors. Germ cells normally occur inside thegonads (ovary and testis). Germ cell tumors thatoriginate outside the gonads may be birth defectsresulting from errors during development of theembryo.Germ cell tumor
A blastoma is a type of cancer, more common inchildren, that is caused by malignancies in precursorcells, often called blasts. Examples arenephroblastoma, medulloblastoma andretinoblastoma. The suffix "-blastoma" is used toimply a tumor of primitive, incompletelydifferentiated (or precursor) cells, i.e.,chondroblastoma is composed of cells resemblingthe precursor of chondrocytes. Blastomas usually occur in children.Blastoma
Gold nanoparticles• Gold nanoparticles (‘nanogold’)occur as clusters of gold atomsup to 100nm in diameter.• Nanogold has unusual visibleproperties because the particlesare small enough to scattervisible light- in contrast, mass gold reflectslight• Gold nanoparticles appear deepred to black in solution- colour depends on size ofnanoparticles• The distance between particlesalso affects colour- surface plasmon resonance isthe term used bynanotechnologists to describethis effect.5nm gold clustersGold nanoparticle
Biological electronic microscopy is one of the areaswhere gold nanoparticles have been extensively used ascontrast agents. They can be associated with manytraditional biological probes such as antibodies, lectins,superantigens, glycans, nucleic acids andreceptors. gold particles having various sizes can beeasily spotted in electron micrographs, it is possible formultiple experiments to be conducted simultaneously.Cont.
Gold nanoparticles are produced in a liquid ("liquidchemical methods") by reduction of chloroauricacid (H[AuCl4]), although more advanced and precisemethods do exist. It can also be synthesised by laserablation.Methods of synthesis of gold nano particles1. Turkevich method2. Brust method3. Perrault Method4. Sonolysis5. Block Copolymer-mediated Method6. Electron MicroscopySynthesis of gold nsnoparticles
Cancer TreatmentsTumor penetration is a key issue for successfulchemotherapy
Nanoparticle use in CancerTreatments• Because of their small size,nanoparticles can pass throughinterstitial spaces between necroticand quiescent cells.• Tumor cells typically have largerinterstitial spaces than healthy cells• Particles collect in center bringingtherapeutics to kill the tumor frominside out.