Product Design Specification Hydrogels for Coating Medical Devices October 5 2006 Team Members Ben Roedl Team Leader Patrick Schenk Communications Darshin Patel BWIG Brett Mulawka BSAC Purpose To form PEG macromer based hydrogels on biomaterial surfaces in an interfacial photopolymerization process and to screen the coatings for interactions with cells and media that mimic physiologic fluids It is hypothesized that these coatings will resist fouling and may be useful for implantable devices Approach The biomaterial specimen is stained with an Eosin solution which is the first component of a 2 part photoinitiator system The stained specimen is immersed in a macromer solution containing component 2 triethanolamine of the photoinitiator system and ferrous and vinyl caprolactam promoters Visible light energy is applied to the aqueous solution At the intersection of the stain the macromer and the light on the surface an adherent thin self limiting hydrogel forms by polymerization of the macromer The coated specimen is exposed to cells in culture and ionic calcium rich media to determine if the cells attach to the coating and spread relative to controls Resistance to such fouling is indicative of utility in applications such as catheters sensors etc Client Requirements Detailed process for applying a hydrogel to surfaces Testing of thickness of hydrogel coatings using a subjective adherence rating system Testing of fouling resistance of hydrogels in various physiologically imitated environments Testing adherence of hydrogels to different materials Resolve logistics of performing experiments Design Requirements 1 Physical and Operational Characteristics a Performance Requirements Testing processes must have universal applications standardized procedures and consistent data collection b Safety The PEG being tested must be non fouling and not negatively affect a physiological environment in any other way Also during the creation and application of the hydrogels the team needs to be conscious of the chemicals they are working with and take necessary precautions 2 c Accuracy and Reliability Although some data will be subjectively collected the same team member will be judging results to ensure consistency d Life in Service Unresolved The hydrogels will need varying service lives based on where and how they are used e Shelf Life All hydrogel reagents have specific needs as far as temperature during storage The hydrogel will not be stored once the desired testing of it is complete f Operating Environment The hydrogel could potentially operate in urine in the case of catheters Possibly blood or interstitial fluid as well g Ergonomics Not Applicable h Size The testing samples will either be one by one square centimeters or one by two square centimeters and between 25 and 100 microns in thickness i Weight Will be determined once the hydrogel tests samples have been produced j Materials i Eosin Y ii Phosphate Buffered Saline PBS 1 NaCl 2 Na2HPO4 Anydrous 3 KH2PO4 3 4 Distilled Water iii Macromer Solution 1 Macromer 3 35KA2 or 20KA2 2 10X Buffer a Triehanolamine TEOA b Potassium Phosphate Monobasic K Phos c Water for Injection WFI d 2 N Hydrochloric Acid HCl 3 N Vinylcaprolactam VC 4 WFI 5 Ferrous Sulfate Heptahydrate 6 D Fructose k Aesthetics Appearance and Finish No appearance requirements 2 Production Characteristics a Quantity One application process and multiple experiments with different materials b Target Product Cost No cost restrictions for testing 3 Miscellaneous a Standards and Specifications None b Customer Genzyme Corporation i Arthur J Coury Ph D Vice President Biomaterials Research c Patient related concerns None at this point 4 d Competition Abbott Labs Amgen Johnson Johnson 5
View Full Document
Unlocking...