Download Prof. Ramamurthy`s lecture

LECTURE 1
Molecular and Supramolecular Photochemistry
Instructor:
nstructor V. Ramamurthy
amamurthy (murthy)
University of Miami, Coral Gables, FL
Email: [email protected]
y
~ 500 pages
~ 1200 pages
X-RAY
INFRARED MICROWAVE
ULTRAVIOLET
Vibrational
infrared
Visible
Ultraviolet
2.5 mm
200 nm
400 nm
BLUE
800 nm
RED
15 mm
RADIO
FREQUENCY
Nuclear
magnetic
resonance
1m
5m
Konark
Modhera
Recognizing the importance of
light, SUN
SUN-its
its ultimate source has
been worshipped in many ancient
cultures Only a few have gone
cultures.
beyond to probe its nature.
Ise Jingū- the Naikū
The Light Paradigm (500 BC-1850 AD)
The light and heat of
the sun is composed of
minute particles.
Lucretius (50 BC)
Particles!
Newton
(1643-1727)
Waves!
Maxwell
(1831-1879)
The Light Paradigm (1850 AD-1900 AD)
E = h
quanta
E = h
photons
Max Planck ((1918))
Albert Einstein ((1921))
E2- E1 = h
Niels Bohr (1922)
E = h = mc2
De Broglie (1929)
Light: Prosperity through basic science
LASER (Light Amplification by the Stimulated Emission of Radiation)
1917: Albert Einstein derives the
theoretical basis for the laser.
1965: The compact laser disc (CD) invented.
1960: The first working (ruby)
laser.
1974: A laser-driven barcode scanner
used for
o tthe
e first
st ttime.
e
The world market for laser technology is now over $100 billion a year
Light: Prosperity through basic science
Oil lamp
Gas arc lamp
Filament lamp
Fluorescent lamp
Light emitting diodes
 Photomedicine
 Lithography
 Industrial Synthesis of Chemicals
 Photography
Photography, Xeorography and
Holography
 Sunsscreen,
S
Ph
Photochromic
t h
i Gl
Glass
 Photostabilization
 Photocuring
 TiO2: Environmental
E i
l Cleanup
Cl
 Solar Energy Conversion
Photomedicine
 Phototherapy - Jaundice treatment
 PUVA therapy - Skin disorders,
disorders Blood cancer
 Photodynamic
Ph t d
i therapy
th
- Cancer
C
 Lasik
i surgery - Vision
i i correction
i
Phototherapy for Neonatal Jaundice Treatment
 Accumulation of the potentially toxic
yellow liphophilic bilirubin in human
serum leads to Jaundice.
 If the percentage of bilirubin
i
increases
to 15-25
1 2 mg/100
/100 mL, it
i will
i
lead to hyperbilirubinemia.
 Severe hyperbilirubinemia cases,
sufficient pigment may partition into
the brain to cause irreversible
damage, even death.
H-O-C
O
O
C-O-H
H
H
NH
N
NH
HN
OO
Bilirubin
McDonagh etal., Science, 208, 1980, 145-151.
Biosynthesis of bilirubin
Glucuronyl transferase activity in fetal and new born liver is very low.
Whyy bilirubin is lipophilic
p p
((hydrophobic)
y
p
)?
Natural Cure for Jaundice
Different ways to cure jaundice
 Wait till liver matures soon enough to clear bilirubin unaided.
 Exchange transfusion: blood along with threatening pigment
drained and replaced
p
with clean blood.
 Phototherapy - irradiate the baby with light.
Discovery of phototherapy
The discovery of phototherapy stems from the observations of
Sister J. Ward, a nurse in U.K.
Evening walk with hyperbilirubinemia patients - lead to
discovery of phototherapy by scientists.
scientists
Phototherapy - Jaundice Treatment
“light
“li ht converts
t bilirubin
bili bi to
t a less
l hydrogen
h d
bonded
b d d
(more water soluble) isomer”
Skin Disorders
Psoriasis
Polymorphic light eruption
Governor of Kerala
Vitiligo
Acute dermatitis
PUVA- therapy

Egyptians and Asian Indians practiced this therapy centuries ago.

Boiled extracts of fruits of plants Ammi majus in Egypt and Psoralea
Corylifolia L in India plus sunlight cured vitiligo.
vitiligo

In 1988
1988, PUVA was the first FDA (Food and Drug Administration)
approved selective immunotherapy for skin disorders including
cancer.
Psoralen + UVA = PUVA therapy
OCH3
O
O
O
How PUVA therapy is done ?
 Methoxsalen capsules are taken two hours before
exposure to UVA.
 Bath PUVA: hands and/or feet are soaked in a dilute
solution of methoxsalen for 30 minutes, then exposed
to UVA.
 A few patients may be treated with topical tripsor
PUVA - a lotion is applied on the affected areas 10
minutes before UVA exposure.
PUVA therapy
OCH3
Psoralen
so e + U
Ultraviolet
v o e A = PUVA
UV
O
O
O
Photoadduct representation with DNA
•
Intercalation
•
Monofunctional adduct ( 3,, 4
with pyrimidine base)
•
Bifunctional crosslinked
adduct(3, 4 and 4’, 5’ with
pyrimidine bases)
PUVA -therapy to treat blood cancer
Centrifugation.
Separate white blood
cells.
Drug in saline + Leukocytes.
Irradiate in the machine.
C ll t white
Collect
hit blood
bl d cells.
ll
Photodynamic therapy
 Photodynamic therapy first used in 1978.
 There is currently one photodynamic drug available on the market:
Photofrin.
 Approved for the treatment of esophageal and lung cancers.
Porphyrins
Chlorins
Phthalocyanines
How does photodynamic therapy work?
 PDT requires sensitizer, light and oxygen
in the target tissue.
 Light generates reactive oxygen species.
 Reactive oxygen species can kill targeted
cells either by necrotic mechanisms or by
initiating the apoptotic cascade.
cascade
Ideal wavelength 650nm
Photodynamic therapy
Laser light source
Directed at target tissue
Light activated PS drug
generates singlet oxygen from
molecular oxygen and kills
cancer cells
PDT effect kills cells
A reaction discovered in 19th century revolutionized the
lithographic industry
C. T. Libermann
1842–1914
Ann. Chem. Pharm. 158, 300, 1871
Photolithography:
g p y Invention 1949-50
Louis Minsk (Kodak)
Otto Suess (Kalley’s)
Louis C. Plambeck (DuPont)
Polyvinylcinnamate-Based
Diazoquinone-Based
Acrylate-Based
Photoressist
Positi e Photoressist
Positive
Photopol mer Imaging
Photopolymer
Photoresist
O
C
C
O
Light
CH
CH
O
+
CH
CH
C
O
C O
O
Applications
pp
of the Principles
p of Photoresists and Lithography
g p y
The Workhorses of Electronics and Printing
•
Printing, Litho, Package, Billboards
•
C l Printing
Color
P i ti
•
Printed Circuit Boards (PC)
•
Integrated Circuit Chips (IC)
•
Photopatterning-DNA and Biochips
•
Micromachines
Fundamental research is the basis for many commercial
products
Lithographic Printing Is the Backbone of Modern
P i ti Industry
Printing
I d t
Gray Shading
Three Color Printing
 Color Printing Requires Color Separation
 Color Printing is Done Through Four Color Processing
Yellow
Magenta
Cyan
Overlay of
the three
Printed Circuit Board Making
Photo Patterning-DNA Chip
Photolithography Applications in Medical Technology
DNA Chips (Micro-array)
(Micro array)
Legends
Several more rounds
of light directed
de-protecting and
nucleotide addition….
Wafer Surface
Linker Molecule
Protective group
Mask
UV light
Nucleotides
Biosensors Based on Photopatterning
Applications
 blood glucose measurements for diabetes
management
 testing food for the presence of pathogenic
g
((Salmonella and E. coli))
microorganisms
 sensing chemical and biological warfare agents
Lithography to Lasik Surgery
R. Srinivasan
S. Blum
J. Wyne
1981:
1981 Di
Discovery off laser
l
ablation
bl ti technique.
t h i
1995: US FDA approval of human Lasik surgery.
2002:
00 : Inducted
duc ed intoo US Inventors
ve o s Hall of
o Fame.
e.
1981: Discovery of laser ablation
1987: Lasik surgery
Photoablation with Excimer Lasers
Short wavelengths of light (190 to 300 nm)
breaks molecular bonds (ablation)
Photoablation with eximer laser (eg: ArF, KrF )
can be done with a micron accuracy.
Refractive surgeries
PRK – Photorefractive keratotomy
LASIK – Laser assisted insitu keratomileusis
How LASIK differs from PRK?

LASER In-situ keratomilieusis (LASIK)

First step is the lifting of corneal flap and then ablation

Treatment is given beneath the flap

Brief recovery time

Very low infection risk and low enhancement rate

Very low risk of scarring and minimal discomfort
J
Japan's
' #1 C
Cosmetic
ti S
Surgery & D
Dermatology
t l
Ch
Chain
i W
World's
ld'
#1 LASIK treatment center: Shinagawa has performed over
600,000 LASIK procedures in Japan
Photochemical synthesis of Rose oxide
Photochemical synthesis of Vitamin – D
Photo-oximation
Photo
oximation - Synthesis of caprolactam
Photochlorination
Nobels in Photochemistry
Development
D
l
t off Flash
Fl h Photolysis
Ph t l i and
d
Femtosecond Chemistry
Norrish
Porter
Zewail
LASER (Light Amplification by the Stimulated Emission of
Radiation) Invention and Innovation
1917: Albert Einstein derives the
theoretical basis for the laser.
Albert Einstein neither invented devices nor made any major
scientific
i ifi discoveries,
i
i yet his
i theories
i greatly influenced
i f
and
shaped the development of late 20th century science and
technology.
Photorefractive Keratectomy
 Cornea reshaped precisely with
excimer laser,, treatment is ggiven on
the corneal surface
 PRK works for myopia, hyperopia
and astigmatism but not for
astigmatism
i
i with
i h hyperopia
h
i
 Healing time is relatively longer
 Used for people whose cornea
epithelium is too thin to create a flap
From Sand to Computer Chips
Photolithography Applications in Electronic Industry
Printed Circuit Boards
Micro-Electro Mechanical Systems (MEMS)