Transcript ARTIFICIAL CELLS

ARTIFICIAL CELLS
Life is endowed with a
mysterious and divine
life-force
Jayanti Tokas1, Rubina Begum1, Shalini Jain2 and Hariom Yadav2
1Department
2 NIDDK,
of Biotechnology, JMIT, Radaur
National Institute of Health, Bethesda,MD20892, USA
Email: [email protected]
Artificial Cells
 Artificial microscopic structures
 Same size as biological cells
 Have some of the functional properties
of biological cells.
 They
contain
biologically
active
materials.
Properties of an ideal minimal cell
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An information carrying polymer
Transport across the membrane
An external source of chemical energy
A catalytic activity
Growth and Division
Regulation
Hypothetical cell like structure
Membranes
 Lipid bilayer vesicles(liposomes)Multilamellar vesicles(MLVs)
* Small unilamellar vesicles(SUVs)-5nm-100nm.
* Large unilamellar vesicles(LUVs)-100nm-1µm.
Smallest biological cell - 0.2-0.5 µm
Transport across cell
membranes
 An assisted mechanism is necessary
• Carrier molecules
• Channels
• Pumps
Channels
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Neutral peptides
Cyclic peptides
α-hemolysin
A tetrameric channel - M2 protein
Energy Supply
 ATP molecules from the environment
 Mimic the energy transduction process
used by all living cells
Encapsulating Macromolecules
 Catalytic activity of the macromolecule is
not damaged
 Dehydration- re hydration method
 Freeze- thaw technique
 Injection of molecules
Micro encapsulation
• To separate functional macromolecules
• Regulate exchange of materials
• Support metabolism
• Transduce environmental energy into
chemical energy
• Synthesize a desired biosynthetic product
Challenges for cell encapsulation
 Optimize
Biocompatibility
Mass transfer
Stability
Reproducibility
 Structural
Functional relationship
Increases Long term stability
Repoducible results
A number of commercial
machines are
available for automatic
production
of artificial cells
Preparation of Artificial cell
Two step Method
Contd..
Contd...
Artificial cells
Like biological cells, Artificial Cells function with
content retained inside to –
 Act on outside permanent molecules
 Release products of interaction
Dimensions of Polymeric Artificial Cells
 Macro dimensions
 For genetically engineered cells, stem cells, other cells, tissues,
microorganisms, etc.
 Micron dimensions
For enzymes, genetically engineered microorganisms and other
microorganisms, peptides, etc.
 Nano dimensions
For blood substitutes, enzymes, peptides, magnetic materials,
drugs, etc.
 Molecular dimensions
For blood substitutes, crosslinked enzymes, conjugated proteins,
etc.
Artificial cells containing biological
cells
 Microencapsulated islets for Diabetes
Mellitus
 Microencapsulated hepatocytes for
liver failure
* Stem cells
Artificial cells containing genetically
engineered cells
 Beta-endorphin secreting cells
 Recombinant ciliary neurotrophic factor
secreting cells
 Oral therapy for Uremia- E.coli DH 5 cells
Artificial cells containing enzymes
 Treatment of enzyme deficiency diseases
* Phenylketonuria
* Lesch Nyan Disease
* Skin Cancer Melanoma
 Urea removal
Artificial cells containing
microorganisms
 Microencapsulation of cholesterol
removing microorganismsPseudomonas pictorum
Artificial Cells With Nano-Dimensions
Typical nano-dimension artificial cells
of 80nm mean diameter
Artificial RBC(Hb +Enz) with all
Biochemical properties
Artificial cells in Molecular
Dimensions
•As Oxygen Carrier
Contd..
Aid in Cancer Therapy
Polymeric Artificial cells Containing
Cells
Cell Content
Aim
Cells and Tissues
Pancreatic cells
Feedback controlled secretion of
insulin for diabetes mellitus
Hepatocytes
To support liver function in liver
failure
Kidney cells
To secrete erythropoietin to treat
anemia
Parathyroid Cells
To secrete parathyroid hormone to
treat hypoparathyroidism
Contd..
Genetically engineered cells
Mouse myoblast (mGH gene) SK2 • Secrete mGH for dwarfism
hybridoma cells
• Secrete anti-hIL-6 monoclonal Abs
for IgG1 plasmacytosis
Mouse myoblasts (human factor IX Secrete human
geen)
hemophilia B
Hamster kidney cells (CNTF gene)
factor
IX
for
Secrete ciliary neutrotrophic factor
for amytrophic lateral sclerosis
Neuro2A cells (pro-piomelaocortin Secrete β-endorphin
gene)
treatment
for
pain
Stem cells
Stem cells plus hepatocytes
Increase duration of viability and
function of hepatocytes
Contd..
Microorganisms
Pseudomonas
pictorum
To remove
Erwinia herbicola
To convert ammonia pyruvate and
phenol into lysine and DOPA
CDH5 E.coli
Urea removal
Metabolic induction of Urea removal
Lactobacilus
delbruecki
Bioactive sorbants
 Activated charcoal and resins
 Ultra thin coating of colloidal membrane
 Detoxify the blood – hemoperfusion.
 McGill Artificial Cells and Organ
Research Centre in the late 1960s.
Hemoperfusion
Patient’s blood
Charcoal-filled artificial cells
Toxins in the blood to enter the cells
Adsorbed by the charcoal.
Artificial cells as drug delivery
vehicles
Drug (biodegradable membrane)
fusion
Target tissue
membrane degraded
Drug released
Artificial cells as biosensors
Artificial cells
analytes
 signal
Coenzyme-depleted enzyme - glucose oxidase
Artificial Cell Membrane Holds
Promise For Medical Use
• Detecting Flue Virus
• Anti-inflammatory Agent
Tailored Glycolipids(sialic acid)
Bind
Specific Protein
(Coat proteins of Influenza virus)
Pink film
Inflammatory Agents
Infection/Injury
Blood Vessels Produce
Receptors
WBC/Neutrophils Bind
Contd..
Excess
* Rheumatoid Arthritis
* Septic Shock
* Clamping of Blood Vessels
During Surgery
Polymerized Membrane
Sugars
Prevents attachment to
Blood Vessels
Artificial red blood cells
 Modified hemoglobin
* high oxygen carrying capacity
* do not have blood group antigens
* longer half life
* non toxic
Extracting Hb from RBC’s
 RBC’s contain Hb which transport O2 through body
 RBC’s are lysed with E-Pure water to extract Hb
E-Pure Water
Modified Hemoglobin
 I generation
 II generation
 III generation
Why Cross-link Hb?
 Hemoglobin must be cross-linked when placed
in the blood stream.
– Hb breaks into dimers which can travel through
capillary pores (holes) and cause death.
+ Cross-linker
In body
Hb dimers are small enough to travel
through pores
Cross-linked Hb can no longer
travel through pores
Present status
 Hemoperfusion for acute poisoning (clinical
trials)
 Hemoperfusion for aluminium and iron overload
(clinical trials)
 Red blood cell substitute (clinical trials)
 Diabetes mellitus animal experiments (clinical
trials)
 Drug delivery systems
 Artificial liver support (experimental)
 Hereditary enzyme deficiency (clinical trials)
NASA supported Researches for dehydrated blood
Supplies
 Artificial Sperm
 Artificial Human Eggs Possible In 5 years
Artificial Human Egg
• Haploidisation
• No Cloning
• Production of Reconstituted Egg
Procedure
Woman’s Somatic Cell
*Remove Nucleus
*Transfer
Shelled Out Oocyte
* Problem
Artificial Sperm
* Dr. Orly Lacham Kalpan succeeded in
fertilizing a normal egg with an artificial
sperm.
* Embryo Developed normally in Lab
Conclusion
• Artificial cells allow to combine properties
of biological systems for therapeutic and
diagnostic applications.
•Artificial cell is an attempt to mimic some of
the biological processes of a real cell, it may
ultimately prove most useful as a partial
substitute for animal cells.