7/6/2016
We will begin momentarily at 2pm ET
Slides available now! Recordings will be available to ACS members after one week.
www.acs.org/acswebinars Contact ACS Webinars ® at
[email protected] 1
Have Questions?
“Why am I muted?” Don’t worry. Everyone is muted except the presenter and host. Thank you and enjoy the show.
Type them into questions box! Contact ACS Webinars ® at
[email protected] 2
1
7/6/2016
Have you discovered the missing element?
http://bit.ly/benefitsACS Find the many benefits of ACS membership! 3
Benefits of ACS Membership Chemical & Engineering News (C&EN) The preeminent weekly news source.
NEW! Free Access to ACS Presentations on Demand® ACS Member only access to over 1,000 presentation recordings from recent ACS meetings and select events.
NEW! ACS Career Navigator Your source for leadership development, professional education, career services, and much more.
http://bit.ly/benefitsACS
4
2
7/6/2016
Let’s get Social…post, tweet, and link to ACS Webinars during today’s broadcast!
facebook.com/acswebinars
@acswebinars
Search for “acswebinars” and connect!
5
How has ACS Webinars benefited you?
®
“The ACS Webinar on high performance elastomers is the standard by which all other presentations should be measured. The material presented was at an easy level and suitable for a broad cross section of the target audience. The speaker was very clear and knowledgeable in the subject. He also kept the talk to 30 minutes, which allowed for a good Q and A session.” Quote in reference to: http://bit.ly/GoElastomers
Richard Walton, Ph.D. Research Associate Goulston Technologies, Inc.
Be a featured fan on an upcoming webinar! Write to us @
[email protected] 6
3
7/6/2016
facebook.com/acswebinars @acswebinars youtube.com/acswebinars
Search for “acswebinars” and connect! 7
Learn from the best and brightest minds in chemistry! Hundreds of webinars presented by subject matter experts in the chemical enterprise. Recordings are available to current ACS members one week after the Live broadcast date. www.acs.org/acswebinars ®
Broadcasts of ACS Webinars continue to be available to the general public LIVE every Thursday at 2pm ET!
www.acs.org/acswebinars
8
4
7/6/2016
ChemIDP.org
POLYMER Division of the American Chemical Society
We invite you to participate in the many activities and benefits of The Division of Polymer Chemistry - one of the largest and most active non-profit, international groups devoted to the advancement of Polymer Science. Become a Member of POLY to enjoy these benefits! • Technical programming at the National ACS meetings • Discounted workshops on contemporary topics in Polymer Science • Industrial scientist support and networking through the IAB (Industrial Advisory Board) • Support for Student Chapters, student symposia, and student awards
www.polyacs.org
10
5
7/6/2016
®
Upcoming ACS Webinars www.acs.org/acswebinars Thursday, July 14, 2016
Insulation Chemistry on Earth and Beyond: Polyimide and Polyamide Aerogels Mary Ann Meador, Senior Scientist, Materials Chemistry and Physics Branch of the Materials and Structures Division, NASA Glenn Paulomi Majumder, Managing Editor of ACS Macro Letters, Biomacromolecules, Macromolecules and ACS Biomaterials Science & Engineering
Thursday, July 21, 2016
Chemistry and the Economy: The Brexit, Challenges of OverSupply and the End of Bank Stimulus Paul Hodges, Chairman of International eChem (IeC) William Carroll, Past ACS President and ACS Chair of the Board
Contact ACS Webinars ® at
[email protected] 11
2016 Material Science Series http://bit.ly/2016MaterialScienceSeries Discover the material science innovations that makes life more comfortable!
The 2016 Material Science Series is co-produced with ACS Industry Member Programs, C&EN, and the ACS POLY Division
12
6
7/6/2016
2016 Material Science Series “The Chemistry of Sight: Material Innovations in Eye Care and Contact Lenses”
Mark Jones
Heather Sheardown
Executive External Strategy and Communications Fellow, Dow Chemical
Professor, Department of Chemical Engineering, McMaster University
Slides available now! Recordings will be available to ACS members after one week
www.acs.org/acswebinars The 2016 Material Science Series is co-produced with ACS Industry Member Programs, C&EN, and the ACS POLY Division
13
THE CHEMISTRY OF SIGHT: MATERIAL INNOVATIONS IN EYE CARE AND CONTACT LENSES
Heather Sheardown
7
7/6/2016
The Eye
15
Contact Lenses • 100 million contact lens wearers worldwide • 1.4% of population but only 4% of 2.4 billion people who wear glasses • To be accepted, contact lenses need to be simpler, more convenient and very very comfortable
16
8
7/6/2016
Contact Lenses 3 types of lenses commonly used •
Rigid gas permeable lenses
•
Soft hydrogel lenses
•
Silicone hydrogel lenses
17
Desirable Properties of Contact Lenses • Ability to correct vision • Comfort in the eye • Low deposition of tear components • Mechanical properties (resistance to tear) • Oxygen permeability
18
9
7/6/2016
Soft Contact Lenses • Developed early 60s – originally from poly (hydroxyethyl methacrylate) • Made from slightly crosslinked hydrophilic polymers •
Polymers added to alter water uptake which determines oxygen permeability
• Generally thought to be very comfortable but limited wear time due to low oxygen permeability
19
Typical Soft Contact Lenses
20
10
7/6/2016
Rigid Gas Permeable Lenses • Introduced in the late 70s • Show high oxygen permeability but lack comfort • Copolymers of PMMA and silicone containing materials – typically methacryloxypropyltris(trimethyoxy) silane + hydrophilic comonomers to impart hydrophilic character to the lenses • Development of fluorine containing RGP lenses based on realization that the fluoroderivatives may improve oxygen permeability and resistance to deposit formation on lenses
21
Composition of RGP Lenses
22
11
7/6/2016
Silicone Hydrogel Contact Lenses • Recognition of outstanding oxygen permeability of silicone rubber • Oxygen transport occurs through the silicone phase rather than water phase as with traditional soft contact lenses • Silicone elastomers on their own stick to the cornea • Combine HEMA with monomer so successfully used in the manufacture of RGP lenses
23
Co-Continuous Phases • Combination of adequate oxygen permeability and adequate ionic or hydraulic permeability • Macromer + TRIS + Solvent, one of which is a hydrophilic monomer
24
12
7/6/2016
Co-Continuous Phases • Combination of adequate oxygen permeability and adequate ionic or hydraulic permeability
25
Monomers Used in Silicone Hydrogel Manufacture
TRIS 26
13
7/6/2016
TRIS Modifications
27
Macromers for Silicone Hydrogels
28
14
7/6/2016
Comparison of Properties of First Two Silicone Hydrogels
29
Oxygen Permeability
30
15
7/6/2016
Audience Survey Question ANSWER THE QUESTION ON BLUE SCREEN IN ONE MOMENT
About how many people worldwide wear contact lenses? • 75 million people
• 105 million people • 115 million people • 130 million people • 150 million people
31
CL Wearers • CL’s represent the most widely used biomaterial worldwide • Worn by 130 million people
– 32 million in US – 3.5 million in Canada • 90% wear SCL
32
16
7/6/2016
Growth in SiHy Materials
Morgan et al, CL Spectrum 2016; 31(1): 28-33
33
Current Issues with Contact Lenses • Protein and lipid adsorption • Rigidity • Surface friction • COMFORT
34
17
7/6/2016
Intraocular Lens Implants •
10 million IOLs are implanted annually in developed world and developing countries
•
Cataracts remains the leading cause of blindness worldwide
35
The Lens •
The lens is situated behind the iris in a small bag-like structure called the lens capsule
•
The lens itself is generally considered to be composed of three layers, appropriately titled the lens nucleus, the lens cortex and the lens epithelium ANTERIOR
epithelial cells
cortical fibres POSTERIOR
nuclear fibres
18
7/6/2016
DISTANCE VISION low power lens relaxed ciliary muscle
cornea NEAR VISION high power lens
contracted ciliary muscle
cornea
Audience Survey Question ANSWER THE QUESTION ON BLUE SCREEN IN ONE MOMENT
When was the first Intraocular Lens (IOL) surgery performed? • 1938 • 1949 • 1954 • 1967 • 1971
38
19
7/6/2016
Current Technologies to Treat Cataracts •
Dr. Harold Ridley is credited with performing the first IOL operation on November 29, 1949
•
He chose polymethyl methacrylate as the his material choice as he observed it induced a negligible tissue response in the eye while working as a military surgeon
39
Current Materials and Designs • Hydrophobic acrylic materials • Hydrophilic acrylic materials • Silicones • Square edged design
40
20
7/6/2016
In Bag Positioning
41
Phakoemulsification
© 2008
42
21
7/6/2016
Progression of IOL Materials
43
44
22
7/6/2016
Problems with Current Technologies •
Approximately 30% of patients with artificial intraocular lenses (IOLs) develop posterior capsule opacification (PCO) within five years of surgery and must undergo a subsequent procedure
•
Currently there are only 3 accommodative IOLs on the market and none effectively reduces the incidence of PCO
© 2008
45
Lens Refilling •
During this technique, the capsular bag is evacuated through a small capsular opening to be then refilled with an elastic polymer capable of responding to adequate change in surface curvature according to the varying zonular tension.
46
23
7/6/2016
In Situ Curable Silicones – Example • • • •
Used ROP to create prepolymers using D4 and D4H Hexaethyldisiloxane used as a cap to control molecular weight Used hydrosilation to create polymerizable groups Cured by UV polymerization within 5 min
47
Drug Delivery to the Eye •
Eye disease is becoming a greater burden on society – Aging population – Increased incidence of health problems – Increased incidence of psychological problems
•
New treatments developed based on increased understanding of biological mechanisms
•
Challenge is delivery to the target tissue
48
24
7/6/2016
Opportunity Pharmacological treatments for back of the eye diseases are a growth industry
Source: Braun Consulting group
49
Problem Biological barriers limit treatment options Both eye drops and systemic administration of drug fail to reach target site at therapeutic concentrations Recurring injection is the status quo Painful, invasive, potentially dangerous, low patient compliance Drug delivery devices are transforming the market Controlled release devices are seen as the next step
Iluvien from Alimera Sciences
50
25
7/6/2016
Audience Survey Question ANSWER THE QUESTION ON BLUE SCREEN IN ONE MOMENT
What percentage of the drug actually gets to the desired target in the eye with topical drops? • About five percent • About ten percent • About twenty percent • About thirty percent • About fifty percent
51
Topical Drops • 90% of current market formulations for disease management – poor insertion technique in >50% • over-spill
– – – –
poor compliance in 50% tear flow drainage diluted by blinking corneal diffusion resistance
• Substantial systemic absorption •
