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Electrospinning of L-Tyrosine Polyurethane Scaffolds for Gene Delivery

Qaqish, Walid P
http://rave.ohiolink.edu/etdc/view?acc_num=akron1416997407

Abstract Details

2014, Master of Science in Engineering, University of Akron, Biomedical Engineering.
Pseudo-poly(amino acids), such as to L-tyrosine polyurethanes (LTUs), are a class of polymers developed to enhance their biocompatibility while offering the ability to tailor mechanical properties. LTU4a, a variant LTU, has been synthesized due to the lack of 1250 Da PCL-marcodiol. LTU4a has been dissolved using a co-solvent of chloroform and hexafluoro-2-propanol (HFIP) and emulsified with aqueous buffer that contained DNA.1 Using a novel in situ stirring device, the emulsion has been maintained throughout the electrospinning process. This method resulted in repeatable `dome’ structures (20-200µm in diameter) within the scaffolds. By varying the speed of the in situ stirring device, the `dome’ diameter size can be controlled and is inversely proportional to the stirring speed. Additionally, degradation products of LTU4a scaffolds exhibits limited toxicity based on the LIVE/DEAD® assay of human dermal fibroblasts (HDF) (>95% viability). The durability of LTU4a scaffolds is shown with limited enzymatic (a-chymotrypsin) degradation (<6%). Furthermore, permeability of emulsion electrospun LTU4a scaffolds decreases as compared to LTU4a scaffolds that only contained fibers using conventional electrospinning methods. Since these domes are hollow and are able to encapsulate aqueous droplets, the in situ stirring device can be used to incorporate bioactive molecules such as plasmid DNA (pDNA). Based on the desirable properties of this electrospinning method, studies has been performed to evaluate the bioactivity of pDNA and polyplexes formed by complexing pDNA with linear polyethylenimine (LPEI). The release of pDNA and polyplexes has been verified via PicoGreen® and gel electrophoresis. However, the released pDNA show damage by restriction enzymatic assays and spectral analysis of the pDNA. The decreased pDNA bioactivity hindered transfection in HDFs. Overall, electrospun LTU4a scaffolds have shown excellent biocompatibility as a tissue engineering platform. Finally, emulsion electrospinning of LTU4a with the in situ stirring device offers new scaffold morphologies, and an easy method to increase the therapeutics used electrospun scaffolds for drug delivery applications
Yang Yun, Dr. (Advisor)
Darrell Reneker, Dr. (Committee Member)
Hossein Tavana, Dr. (Committee Member)
139 p.
Biomedical Engineering; Biomedical Research; Polymers
L-Tyrosine, Polyurethanes, Electrospinning, Emulsion, Drug Delivery, DNA

Recommended Citations

Citations

  • Qaqish, W. P. (2014). Electrospinning of L-Tyrosine Polyurethane Scaffolds for Gene Delivery [Master's thesis, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1416997407

    APA Style (7th edition)

  • Qaqish, Walid. Electrospinning of L-Tyrosine Polyurethane Scaffolds for Gene Delivery . 2014. University of Akron, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1416997407.

    MLA Style (8th edition)

  • Qaqish, Walid. "Electrospinning of L-Tyrosine Polyurethane Scaffolds for Gene Delivery ." Master's thesis, University of Akron, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1416997407

    Chicago Manual of Style (17th edition)

akron1416997407
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© 2014, some rights reserved.Creative Commons License Electrospinning of L-Tyrosine Polyurethane Scaffolds for Gene Delivery by Walid P Qaqish is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by University of Akron and OhioLINK.