Polymer Frequently Asked Questions
Block polymers and biodegradable polymers
- Will your polymer(s) work for my application?
- PLA, PLGA, PEG, biodegra...what? I'm a specialist in (insert field here) but I need to start from scratch on these polymers.
- Have these polymers (or similar ones) been involved in any clinical trials yet?
- Are your materials GMP?
- Are these cGMP?
- Can you synthesize different sizes than what we see in the catalog?
- Who is PolySciTech® affiliated with?
- How do I order?
- How is payment handled?
- Can I request custom synthesis?
- What are your standard terms and conditions?
- Do you provide free samples?
- Do you offer discounts to universities?
- Do you ship to (insert country here)?
- Is there a minimum order for custom synthesis?
Will your polymer(s) work for my application?
Answer: By far this is the most common question. The honest answer is that without great detailed information about your application, and in some cases even with great detailed information about your application, we cannot tell you for certain. The polymers you see below are utilized for medical and biochemical research. Popular applications include micelles, thermoreversible gels, and solid formulations (coating, nanoparticles, etc.). Another popular application which includes all of the previously mentioned ones is delivery of a drug. By no means are these the only applications, ground-breaking research is being performed on these polymers daily and so applications of these polymers are continually expanding. Recent research utilizing these types of polymer for these various applications can be found below in the Applications section.
PLA, PLGA, PEG, biodegra...what? I'm a specialist in (insert field here) but I need to start from scratch on these polymers.
The polymers listed below are utilized for biomedical implants and drug delivery. These polymers include two main types of units, biodegradable and water soluble:
Biodegradable units include lactic, glycolic, and caprolactone units have ester linkages which react with water forming soluble acids. These acids are either metabolized or harmlessly flushed away in a normal mammalian body. See the following links for more details on biodegradable polymers:
The rate of biodegradation of these polymers generally follows the pattern:
- (Fastest degradation) PLGA < P(D,L)LA < P(L)LA << PCL (Slowest degradation)
Water Soluble Unit
The water soluble unit in each case includes poly(ethylene glycol)(PEG). PEG is noted for good biocompatibility with a low immunogenic response (See: http://www.jbc.org/cgi/reprint/252/11/3578). Although PEG is not biodegradable on any meaningful time scale, it can be screened out of the body by the kidneys and excreted as long as its molecular weight is less than 10,000 Da*. These units compromise one or more blocks depending on whether the polymer is a diblock (one polyethylene glycol arm and one biodegradable arm) or a triblock (two biodegradable arms on either side of the polyethylene glycol arm).
Have these polymers (or similar ones) been involved in any clinical trials yet?
Yes, there are currently clinical trials underway utilizing PEG-PLA as a means to deliver Genexol-PM. See: http://clincancerres.aacrjournals.org/cgi/reprint/10/11/3708
Are your materials GMP?
At this time PolySciTech® lacks the in-house capability to generate GMP grade materials directly. If you are interested in GMP non-block polyesters and other GMP polymers/materials please contact Purac (www.purac.com).
Are these cGMP?
No, the polymers provided are strictly for research purposes. To the best of our knowledge, there are not yet any commercial cGMP sources of these polymers.
Can you synthesize different sizes than what we see in the catalog?
Yes, typically if you are seeking a block size that is not currently in our catalog we will treat this as a customer request rather than a custom synthesis. The difference is in a customer request we simply manufacture then sell it to you at list price and add the remainder of the batch to our catalog. In the case of custom synthesis you will have either the entire batch or the remainder of the batch will not be sold and so the chemical will be exclusively yours. This is more often the case for extreme specialty polymers such as custom endcapped/specially shaped materials. If you are just looking for different block sizes and do not require exclusivity of the batch then this can be generated as a customer request.
Who is PolySciTech® affiliated with?
PolySciTech® is the research polymer and materials division of Akina, Inc., which was founded by Dr. Kinam Park in 2001 and is located in West Lafayette, Indiana.
How do I order?
Contact John Garner (email@example.com, (765) 464-0390 Extension 304). Orders are accepted in whatever manner befits your organization. A PO number is preferred, but not necessary.
We ship polymers overnight in cold packs (insulated containers) to assure they stay cool and fresh.
Orders placed after Noon US Eastern time, or for polymers not in stock, may not be shipped the same day.
Polymers not in stock may take 3-5 weeks, depending on their chemistry.
How is payment handled?
Payment is handled at time of purchase via credit card. Akina accepts payment via Discover, MasterCard, or Visa. Akina Inc. does not extend credit or provide financing.
Can I request custom synthesis?
Yes, Akina Inc. does perform custom synthesis. Price and availability will depend on the product you are requesting.
What are your standard terms and conditions?
Click here to see the list of standard terms and conditions.
Do you provide free samples?
Given the cost of the materials we cannot as a policy provide free samples.
Do you offer discounts to universities?
You can see more about our discounts on our discounts page (http://polyscitech/products/polyvivo/discounts.php).
Do you ship to (insert country here)?
Yes, we ship to any country that is serviced by UPS or Fedex, and banks. If you are in Japan you can purchase our products from our one of our distributors, Funakoshi (http://www.funakoshi.co.jp/export/).
Is there a minimum order for custom synthesis?
Yes, the minimum order for custom synthesis is 1 gram.
The potential applications of these materials are far too broad to cover here. What follows are general references and links to information regarding each application. Hopefully this information will be useful in deciding if these polymers will work for your application.
Micelle Delivery to Target Cancer Cells
Micelles from PEG-PCL
Moon Suk Kim, Hoon Hyun, Young Ho Cho, Kwang Su Seo, Woo Young Jang, Sun Kyung Kim, Gilson Khang, Hai Bang Lee. "Preparation of methoxy poly(ethyleneglycol)-blockpoly(caprolactone) via activated monomer mechanism and examination of micellar characterization." Polymer Bulletin 55: p.149-156. 2005.
Thermogel/ Tissue Engineering
Thermogelling properties of PLA-PEG-PLA triblock
Thermogelling properties of PEG-PLGA
"Sol-Gel Transition Temperature of PLGA-g-PEG Aqueous Solutions" Young-Me Chung, Kevin L. Simmons, Anna Gutowska, and Byeongmoon Jeong. Biomacromolecules 2002, 3, 511-516
Thermogelling properties of PEG-Biodegradable
"Preparation of Methoxy Poly(ethylene glycol)/Polyester Diblock Copolymers and Examination of the Gel-to-Sol Transition." Moon Suk Kim, Kwang Su Seo, Gilson Kwang, Sun Hang Cho, Hai Bang Lee. Journal of Polymer Science Part A: Polymer Chemistry 42 : p. 5784-5793. 2004.
Thermogelling properties of PLGA-PEG-PLGA
Thermogelling properties of PEG-PLA
*"Biodegradable Block Copolymers as injectable Drug Delivery Systems" Byeongmoon Jeong, You Han Bae, Doo Sung Lee, and Sung Wan Kim. Nature 388. p. 860-862. 1997.
Below is an example of solid pellets plasticized to improve the delivery of protein based drugs:
"New synthetic absorbable polymers as BMP carriers: Plastic properties of poly-D,L-lactic acid-polyethylene glycol block copolymers" Naoto Saito, Takao Okada, Shigeyuki Toba, Shimpei Miyamoto, Kunio Takaoka Journal of Biomedical Materials Research Part A Volume 47, Issue 1 , Pages 104 – 110.
Polyethylene glycol block is known to reduce the adsorption of proteins. From a biocompatibility standpoint, this is an improvement over the relatively hydrophobic PLA/PGA, which may allow protein adsorption. Protein adsorption is the first step towards thrombosis in blood contacting materials. For more information and a comparison study between block and non-block polymer check out:
- "Modulation of marrow stromal cell function using poly(D,L-lactic acid)-block-poly(ethylene glycol)-monomethyl ether surfaces" Achim Göpferich, Susan J. Peter, Andrea Lucke, Lichun Lu, Antonios G. Mikos Journal of Biomedical Materials Research Part A Volume 46, Issue 3 , Pages390 – 398
General Degradation Properties
As a general rule, the larger the PEG block relative to the PL/GA the more rapid the degradation.
"Degradation behavior of block copolymers containing poly(lactic-glycolic acid) and poly(ethylene glycol) segments" Maurizio Penco, Silvia Marcioni, Paolo Ferruti, Salvatore D'Antone and Romano Deghenghi. Biomaterials, Volume 17, Issue 16, 1996, Pages 1583-1590