BME Summer Seminar - Wednesday, June 17
Event Date: | June 17, 2015 |
---|---|
Hosted By: | Weldon School of Biomedical Engineering |
Time: | 12:30 p.m. |
Location: | MJIS 2001, WL campus |
Thiol-ene hydrogels crosslinked by cyclodextrin and poly(ethylene glycol) for forming immuno-protective islet coating
Han Shih (Dr. Chien-Chi Lin and Dr. Alyssa Panitch, co-advisors)
Abstract: Type I diabetes mellitus (T1DM) is an autoimmune disease caused by the destruction of insulin-producing β-cells by auto-reactive T-cells. Although islet transplantation holds the promise of permanently reversing T1DM, significant shortage of donor islets, as well as the need for lifelong immunosuppressant therapy limits the clinical prevalence of this approach. An effective microencapsulation strategy should serve as an immuno-isolation barrier to protect the transplanted islets from host immune response such as instant blood mediated inflammatory reaction (IBMIR). To achieve this goal, we have developed hydrogel conformal coating using a visible light-mediated interfacial thiol-norbornene photopolymerization. Upon visible light exposure, photosensitizer eosin-Y extracted hydrogen from a thiol-containing crosslinker (e.g., DTT) to form thiyl radicals that reacted orthogonally with the norbornene moieties on PEG-norbornene (PEGNB) to form a thiol-ene hydrogel. Unlike conventional visible light polymerizations, no additional cytotoxic co-initiator or co-monomer was required in thiol-ene gelation system. The step-growth thiol-norbornene coating also afforded high consistency and tunability. More importantly, isolated islets coated with thiol-norbornene gel maintained their viability and function in vitro. We also developed a cytocompatible thiol-ene hydrogel crosslinked by β-cyclodextrin (βCD) to allow the inclusion of curcumin, an anti-inflammatory drug candidate with poor water solubility. These CD-containing hydrogels were cytocompatible to pancreatic β-cells. Furthermore, the incorporation of βCD enhanced the uptake and prolonged the delivery of hydrophobic curcumin. Future work will focus on combining visible light mediated step-growth thiol-ene conformal coating and anti-inflammatory drug delivery strategies to prolong the survival of transplanted islets.
Tissue Analysis using a miniature Mass Spectrometer
Ran Zou (Dr. Zheng Ouyang, advisor)
Abstract: Lipidomics has emerged as a potential field for biomarker discovery for human diseases. Direct tissue analysis using mass spectrometry can provide highly specific molecular information. Performing direct analysis in clinical settings requires a reliable and portable approach, which likely to use a miniature mass spectrometer with direct sampling ionization capability. A desktop Mini 12 designed for point-of-care applications was used in this study with extraction spray for direct profiling fatty acids and lipids from biological tissues. Photochemical derivatization using Paternò-Büchi (PB) reactions was also implemented for quantifying the relative abundances of the unsaturated isomers of the lipids.
Tissue samples from rat brain, kidney, and liver were used for the method development and characterization. NanoESI electrode holder was gently inserted into the tissue sample and then pulled out. It was then inserted into a borosilicate capillary filled with 10μL methanol for sample extraction. A UV lamp of 6W at 254nm was placed near the MS inlet for the PB reaction and acetone/water (50/50) were used as the extraction ionization and reaction solvent, respectively. A DC of 1500V was applied on the wire to generate nanoESI for MS/MS analysis by the Mini 12 with a discontinuous atmospheric pressure interface.
Paternò-Büchi reaction combined with the Mini 12 mass spec system can confidently and efficiently determine the locations of C=C double bond in the fatty acid of rat brain tissue. Our future efforts aim to conduct comparative studies of the normal and cancerous tissues using this the Mini 12 MS system. This easy-to-operate system and fast analysis method should be feasible for use by doctors, surgeons, and biologists.
***Bring your lunch to seminar – BMEGSA will provide snacks and drinks***
Seminar will also be available via WebEx meeting in SL220A at IUPUI*
2015-06-17 12:30:00 2015-06-17 13:30:00 America/Indiana/Indianapolis BME Summer Seminar - Wednesday, June 17 Two BME graduate students, Han Shih and Ran Zou, will present their research progress in the Weldon School's weekly seminar series, to begin at 12:30 p.m. on Wednesday, June 17, in MJIS 2001. MJIS 2001, WL campus