B IOMATERIALS L AB N ETWORK D EGRADATION Monday, February 6 th and Tuesday, February 7 th

P RE-LAB  Sign-in  Quiz (Metters. 2000)

Rectangular Approximation "Approximating the Area Under a Curve for AP Calculus | Education.com." Education.com | An Education & Child Development Site for Parents | Parenting & Educational Resource. Web. 06 Feb

Procedural Notes  Teamwork  Take turns pipetting, massing, ect. but make sure you remember what has been added to the solution  Pipetting  Check the volume, change by twisting dial  When filling, go to first stop  When ejecting precursors, go to second stop  When ejecting into syringe mold, go to first stop (to avoid bubbles)

L INEAR M OLECULES  PEG-PLA-MA  MSAMAA (CH 2 ) 4

1 “Arm” PEGMAPLA (Lin, C.C., Pharmaceutical Research. 26(3): ) Step-growth Polymerization Unlike last lab, each double bond can hook up with TWO other molecules. M ETHACRYLATE P OLYMERIZATION ……

S ECTION 1 PEG-PLA-MA Network Synthesis  Can surmise from Metters.2000 this will be bulk degrading  Monitor change in network over time…  Size (diameter / height)  Weight  Young’s Modulus  Stereo-microscopy Imaging Polyanhydrides. Wikipedia. 2011

PEG N ETWORK S YNTHESIS 1.10wt% PEG-PLA-MA in PBS 2.10% photo-initiator by volume (LAP) 3.40μL placed in 1mL syringe (tip cut off)  to create cylindrical hydrogel sample geometry 4.exposed to UV-lamp for 10min 5.Remove and place in PBS 6.3 PEG samples

S ECTION 2 MSA/MAA Network Synthesis  Glassy polymer  Monitor change in network over time…  Size (diameter / height)  Weight  Young’s Modulus  Stereo-microscopy Imaging Polyanhydrides. Wikipedia (CH 2 ) 4

MSA/MAA N ETWORK S YNTHESIS Unlike PEG-PLA-MA, the MSA/MAA is a bulk reaction that is not polymerized in a liquid phase. 1.≈0.25g of MSA/MAA 2.0.1wt% DMAP photo-initiator added to PA-MA 3.Fill mold “sandwich” (glass slide / Teflon / glass slide) 4.exposed to UV-lamp for 10min 5.Remove and place in PBS 6.1 MSA/MAA sample

T ESTING  Young’s modulus in Materials Testing Lab – 5N load cell  Mass – after patting networks dry  Size – use calipers for height and diameter. Don’t squish hydrogel  All three will be assembled and posted on blackboard.  Stereo-microscopy Imaging – collect images with digital camera  Each group is responsible for collecting their own images  All performed on D0, D1, D3, D8, D10

Big Picture  Control of mechanical properties & degradation behavior allows tuning to your application  Ex: Control degradation rate  Control drug release rate  Bulk  Typically hydrophilic  Biologically inert  Large number of available chemistries  Surface  Typically hydrophobic  Protein adsorption, cell interaction  Constant turnover at surface  difficult to integrate with tissue  Applications  Prevent postsurgical adhesion formation  In vivo drug and protein delivery  Temporary scaffold for tissue repair  Degradable sutures

S ECTION 3 Degradation time-course  Look at how networks degrade over time  1 team member per data collection day D AY Monday’s LabTuesday’s Lab 0Monday, February 6 th (in lab)Tuesday, February 7 th (in lab) 1Tuesday, February 7 th Wednesday, February 8 th 3Thursday, February 9 th Friday, February 10 th 8Tuesday, February 14 nd Wednesday, February 15 th 10Thursday, February 16 th Friday, February 17 th