Medical Biotechnology

1
Chapter 11

• Medical Biotechnology

2
Detecting and Diagnosing Human Disease Conditions

• Models of Human Disease
• Identify diseases and test therapies before
  clinical trials in humans
• Clinical trials three phases
• Phase I safety studies- safe dose and how to
  administer the dose (ADME)
• Phase II few hundred patients for the purpose of
  testing effectiveness
• Phase III effectiveness compared to other drugs
  involve thousands of patients often with
  different backgrounds and stages of illness
  throughout the country

3
Detecting and Diagnosing Human Disease Conditions

• FDA Oversight of Drug Development Process
• Clinical Trials

Video What is a Clinical Trial?
4
Detecting and Diagnosing Human Disease Conditions

• Lab to Market Failure
• Limited biomarkers to optimize treatment
• Inadequate experimental approaches for patient
  selection
• Limitations in animal models

Interactive Map of Current US Clinical Trials
5
Detecting and Diagnosing Human Disease Conditions

• Models of Human Disease
• Rat gene, ob, also found in humans therefore
  homologous
• Codes for a protein hormone called leptin if
  missing leads to obesity
• Found that treating obese children defected in
  this gene with leptin decreases their weight

6
Detecting and Diagnosing Human Disease Conditions

• Models of Human Disease
• Organism has 959 cells, 131 of them are destined
  to go through apoptosis
• Study programmed cell death in this organism
• Programmed cell death important to correct
  development of the fetus and improper cell death
  is implicated in Alzheimers, Lou Gehrigs,
  Huntingtons, Parkinsons

7
Detecting and Diagnosing Human Disease Conditions

• Models of Human Disease
• Heart attack mice
• Defect in genes for cholesterol uptake
• HIV small animal model

HIV Clinical Trials
8
Detecting and Diagnosing Human Disease Conditions

• Detecting Genetic Diseases

9
Detecting and Diagnosing Human Disease Conditions

• Molecular Diagnostics
• The use of DNA, RNA, and proteins to facilitate
  disease detection, diagnosis, subclassification,
  prognosis, and monitoring response to therapy

10
Detecting and Diagnosing Human Disease Conditions

• Advantages of Molecular Diagnostics
• Improvement in sensitivity
• High specificity
• Cost less
• Faster analysis time

11
Detecting and Diagnosing Human Disease Conditions

• Detecting Genetic Diseases
• Fetal testing for chromosome abnormalities and
  defective genes
• Amniocentesis (Test at 16 weeks - karyotype)
• Chorionic villus sampling (Test at 8 to 10 weeks
  - karyotype)

12
Detecting and Diagnosing Human Disease Conditions

• Detecting Genetic Diseases
• Testing for chromosome abnormalities and
  defective genes
• Fluorescence in situ hybridization (FISH)
• Fluorescence probes that are specific for
  chromosomes and/or genes
• Spectral karotype

13
Detecting and Diagnosing Human Disease Conditions

• Detecting Genetic Diseases
• Testing for chromosome abnormalities and
  defective genes
• RFLP (restriction fragment length polymorphisms)

14
Detecting and Diagnosing Human Disease Conditions

• Hybridization - single-stranded oligonucleotides
  are permitted to interact so that complexes, or
  hybrids, are formed by molecules with
  sufficiently similar, complementary sequences
• Target - the nucleotide sequence the
  oligonucleotide is designed to hybridize with
• Probe - the nucleic acid that carries a marker
  for detection

Making SNPs Make Sense
15
Detecting and Diagnosing Human Disease Conditions

• Dot Blots
• Assay for detecting SNPs
• Uses PCR amplified DNA blotted onto a membrane
• Unbound ASO probe is washed off
• Bound ASO probe is detected by radioactive or
  colorimetric assays

Dot Blot animation
16
Detecting and Diagnosing Human Disease Conditions

• Allele-Specific Oligonucleotide (ASO) Dot Blot to
  detect Sickle Cell Anemia

17
Detecting and Diagnosing Human Disease Conditions

• Reverse Dot Bot
• Instead of binding DNA to the membrane, an array
  of ASOs are bound to a membrane and hybridized to
  labeled target DNA

Reverse Dot Blot video
18
Detecting and Diagnosing Human Disease Conditions

• Detecting Genetic Diseases
• Single Nucleotide Polymorphisms (SNPs)
• One of the most common forms of genetic variation
• Estimated that one SNP occurs approximately every
  1,000-3,000 bp in the human genome
• 99.9 percent of the DNA sequence will be exactly
  the same gt 80 of 0.1 percent variation will be
  SNPs
• Most have no effect because they occur in
  non-protein coding regions (introns)
• 10 pharmaceuticals donated millions in a
  collaborative partnership called the SNP
  Consortium

19
Detecting and Diagnosing Human Disease Conditions

• Microarray
• A chip containing thousands of pieces of single
  stranded DNA molecules
• DNA is isolated from a patient, fluorescently
  labeled, and hybridized to the microarray
• A laser scanner measures the intensity of the
  fluorescence to indicate the binding of the
  patients DNA to the SNP or gene on the microarray

20
Detecting and Diagnosing Human Disease Conditions

• Detecting Genetic Diseases
• Identifying sets of disease genes by microarray
  analysis
• Microarray created with known diseased genes or
  SNPs
• DNA from a patient is tagged with fluorescent
  dyes and then hybridized to the chip
• Binding of a patients DNA to a gene sequence on
  the chip indicates that the persons DNA has a
  particular mutation or SNP

21
Medical Products and Applications of Biotechnology

• Pharmacogenomics individualized medicine based
  on a persons genetic information

Pharmacogenomics Animation
22
Medical Products and Applications of Biotechnology

• The search for new medicines and drugs
• Oncogenes- genes that produce proteins that may
  function as transcription factors and receptors
  for hormones and growth factors, as well as serve
  as enzymes involved in a wide variety of ways to
  change growth properties of cells that cause
  cancer
• Tumor Suppressor Genes regulate oncogenes

23
Medical Products and Applications of Biotechnology

• The search for new medicines and drugs
• Personalized Medicine
• BRCA1 or 2 increases risk of developing breast
  cancer
• But there are many other cases of breast cancer
  that do not exhibit this mode of inheritance
• They SHOULD be treated differently (i.e.
  different chemotherapy!)

24
Medical Products and Applications of Biotechnology

• Microarray technology
• Can compare levels of gene expression in
  different tissues
• Applications in cancer research

Microarray animation
25
Medical Products and Applications of Biotechnology

• The search for new medicines and drugs
• Improving techniques for drug delivery
• Factors that influence drug effectiveness
• Drug solubility
• Drug breakdown
• Drug elimination

26
Medical Products and Applications of Biotechnology

• Microparticle Drug Delivery
• Microspheres tiny particles that can be filled
  with drugs

Drug Delivery Video
27
Medical Products and Applications of Biotechnology

• Nanotechnology area of science involved in
  designing, building, and manipulating structures
  at the nanometer
• (nm) scale

Nanotechnology video
28
Medical Products and Applications of Biotechnology

• Polymer based nanomedicine

Targeted Medicine Video
29
Medical Products and Applications of Biotechnology

• Nanobots manufactured device with embedded
  sensors to facilitate target identification and
  drug delivery

30
Medical Products and Applications of Biotechnology

• Vaccines and Therapeutic Antibodies
• Vaccines stimulate immune response
• Also hope that vaccination may be useful against
  conditions such as Alzheimers disease or drug
  addiction
• Using antibodies in some types of therapies
  Development of Monoclonal Antibodies

31
Gene Therapy

• Gene Therapy treating disease by inserting
  functional genes to replace defective ones

32
Gene Therapy

• A vector delivers the therapeutic gene into a
  patients target cell
• Functional proteins are created from the
  therapeutic gene

Gene Therapy Animation
33
Gene Therapy

• Ex vivo Gene Therapy

• In vivo Gene Therapy

Gene Therapy Video
34
Gene Therapy

• Vectors for Therapeutic Gene Delivery

• Non-Viral

• Viral

Animation Gene Therapy Vectors
35
Gene Therapy

• 1990 4 year old Ashanti DaSilva had a genetic
  disorder called severe combined immunodeficiency
  (SCID)
• Defect in ADA gene results in an accumulation of
  dATP, which is toxic to certain types of T cells
• Takes down the entire immune system

36
Gene Therapy

• Case Study Cystic Fibrosis
• Defective cystic fibrosis transmembrane
  conductance regulator (CFTR)
• Normally it serves as a pump at the cell membrane
  to move electrically charged chloride atoms out
  of the cells
• If cells cant move chloride out, they absorb
  water trying to dilute the chloride in the cell
• This leads to the production of THICK sticky
  mucus

Animation Cystic Fibrosis Case Study
37
Gene Therapy

• Gene Therapy in Clinical Trials

38
Gene Therapy

• Challenges
• Adverse effects of viral vectors
• Targeting specific cells
• Controlling expression of the therapeutic gene
• Long lasting therapy

Video Challenges of Gene Therapy
39
Regenerative Medicine

• Growing cells and tissues that can be used to
  replace or repair defective tissues and organs

Regenerative Medicine Video
40
Regenerative Medicine

• Tissue Engineering - replacement of tissues and
  organs by growing them in culture
• Cell based
• Scaffold guided

Video Tissue Engineering
41
Regenerative Medicine

• Cells Based Tissue Regeneration
• Fetal tissue grafts
• Nanofibers

42
Regenerative Medicine

• Scaffold Guided Tissue Regeneration
• Creates framework onto which cells
• are seeded and bathed in growth
• factors

43
Regenerative Medicine

• Application Bone regeneration

Bone regeneration animation
44
Regenerative Medicine

• Application Blood Vessel regeneration

Animation of blood vessel regeneration
45
Regenerative Medicine

• Cells and Tissue Transplantation
• Organ transplantation
• Autograft transplanting a patients own tissue
  from one region of the body to another- ex. Vein
  from leg used in coronary bypass-organ
  transplants are between individuals and so must
  be checked for compatibility
• Histocompatibility complex - gt70 genes which
  produce tissue typing proteins (must match!)
• There are many different types of MHC proteins
  (one group is called human leukocyte antigens or
  HLAs)- have been using immunosuppressive drugs
  but there are problems.

46
Regenerative Medicine

• Cells and Tissue Transplantation
• Organ transplantation
• Xenotransplantation transfer between species
  (pig to human)
• University of Missouri scientists have produced
  cloned, knockout pigs that lack a gene called
  GGTA1 (or 1,3 galactosyltransferase)
• The gene normally codes for a sugar that would be
  recognized as foreign by humans

47
Regenerative Medicine
Video Growing Body Parts
48
Regenerative Medicine

• Bioprinting - The construction of a biological
  structure by computer-aided, automatic,
  layer-by-layer depositing of bioink onto
  biopaper.
• Bioink cells from patient
• Biopaper thin gel layers

Bioprinting Video
49
Regenerative Medicine

• Embryonic Stem Cells cells derived from a
  blastocyst that can differentiate into any type
  of cell in the body

Stem Cell Animation
50
Regenerative Medicine

• Culturing embryonic stem cells

51
Regenerative Medicine

• Applications of embryonic stem cells

52
Regenerative Medicine

• Problems with embryonic stem cell therapies
• Tumor formation

53
Regenerative Medicine

• Adult Derived Stem Cells cell from mature
  tissue that can be cultured and differentiated to
  become any cell type from the organ of origin

54
Regenerative Medicine

• Adult Derived Stem Cells
• Hematopoietic stem cell therapy

55
Regenerative Medicine

• Adult Stem Cell Applications Heart Disease

56
Regenerative Medicine

• Adult Stem Cell Applications
• Cord Blood Banking

Animation Types of Stem Cells
57
Regenerative Medicine

• Embryonic Stem Cells

• Adult Stem Cells

• Pluripotent
• Possible transplant rejection

• Multipotent
• Autologous stem cells reduce chance of rejection

stem cell therapies
58
Regenerative Medicine

• Induced Pluripotent Stem Cells (iPSCs)
• mature body cells that have been reprogrammed to
  change their identities and revert back to an
  embryolike state

59
Stem Cells

• Induced Pluripotent Stem Cells (iPSCs) Methods
• Using viruses to insert the genes necessary for
  reprogramming

60
Stem Cells

• Induced Pluripotent Stem Cells (iPSCs)
  Applications
• Disease modeling
• Cell and tissue regeneration
• Treating genetic disorders

61
Stem Cells

• Induced Pluripotent Stem Cells (iPSCs) Questions
• Possible tumor formation
• Poorly controlled pluripotency

62
Regenerative Medicine

• Cloning
• Therapeutic Cloning and Reproductive Cloning