Author: ccrosby (Page 3 of 6)

Alicia Allen has recently published in Biomaterials Science on generating anisotropic cell sheets from electrospun fibers. The fibers are  a blend of two polymers, one that is cell adhesive (PCL) and one that is thermosensitive (PNIPAAm). When PNIPAAm undergoes a temperature induced phase transition, the cells detach; therefore, this method is both inexpensive and enzyme-free. The abstract can be found below:

Cell alignment in muscle, nervous tissue, and cartilage is requisite for proper tissue function; however, cell sheeting techniques using the thermosensitive polymer poly(N-isopropyl acrylamide) (PNIPAAm) can only produce anisotropic cell sheets with delicate and resource-intensive modifications. We hypothesized that electrospinning, a relatively simple and inexpensive technique to generate aligned polymer fibers, could be used to fabricate anisotropic PNIPAAm and poly(caprolactone) (PCL) blended surfaces that both support cell viability and permit cell sheet detachment via PNIPAAm dissolution. Aligned electrospun PNIPAAm/PCL fibers (0%, 25%, 50%, 75%, 90%, and 100% PNIPAAm) were electrospun and characterized. Fibers ranged in diameter from 1–3 μm, and all fibers had an orientation index greater than 0.65. Fourier transform infrared spectroscopy was used to confirm the relative content of PNIPAAm and PCL. For advancing water contact angle and mass loss studies, only high PNIPAAm-content fibers (75% and greater) exhibited, temperature-dependent properties like 100% PNIPAAm fibers, whereas 25% and 50% PNIPAAm fibers behaved similarly to PCL-only fibers. 3T3 fibroblasts seeded on all PNIPAAm/PCL fibers had high cell viability and spreading except for the 100% PNIPAAm fibers. Cell sheet detachment by incubation with cold medium was successful only for 90% PNIPAAm fibers, which had a sufficient amount of PCL to allow cell attachment and spreading but not enough to prevent detachment upon PNIPAAm dissolution. This study demonstrates the feasibility of using anisotropic electrospun PNIPAAm/PCL fibers to generate aligned cell sheets that can potentially better recapitulate anisotropic architecture to achieve proper tissue function.

Alicia Allen, a fourth year graduate student in the Zoldan Lab, passed her proposal on June 22nd. Alicia discussed her recent work on the generation of aligned cell sheets and proposed leveraging her current system to produce aligned cardiac patches. Congratulations Alicia

Snow Leopard

Chengyi Tu, a fourth-year graduate student in the Zoldan Lab, has passed his thesis proposal. He proposes to investigate how reactive oxygen species and the PI3k pathway direct stem cell fate, with a detailed focus on cardiac stem cell differentiation. Congratulations Chengyi!

Chengyi, with his new orca, ROS!

Elissa Baron (working with Alicia Allen) and David Shu (working with Cody Crosby) received undergraduate research fellowships (URFs), which includes a stipend of $1000.00 to aid their research. From the UT Office of the Vice President for Research:

The Undergraduate Research Fellowship (URF) program provides support for specific scholarly research projects conducted by full-time UT undergraduate students enrolled in any department. These fellowships are intended to cover costs associated with academic research projects proposed and written by student applicants and undertaken with the supervision of a university tenured or tenure-track faculty member, lecturer, senior lecturer or full-time research scientist/engineer.

The Zoldan Lab congratulates Elissa Barone, who presented her research on fiber alignment and its effect on cardiomyocyte differentiation at the Undergraduate Research Symposium in December 2016. Elissa is currently working with Alicia Allen.

Krista Polansky, a sophomore who is working with Julie Strickland, received an undergraduate research fellowship. She proposes to use this fellowship to isolate the individual progenitor cell populations found in murine neurospheres.

We’re happy to announce that Julie Strickland, a second-year in the Zoldan Lab, passed her qualifying exam! She discussed her plan for developing a hydrogel platform to rescue neurons in the brain.

Congrats to Jorge Gomez Medellin , who recently won an URF for his research (under Alicia Allen) on aligning cardiomyocytes on electro-spun scaffolds!

On April 4th, Dr. Zoldan attended a meeting of tissue engineers and material scientists in Bethseda, MD hosted by the National Eye Institute to assist in the development of retina organoid technology and set appropriate benchmarks for progress in the field.  Recent publications have highlighted the significance of creating 3D optic cups that mimic developmental process in humans.

On April 7th, Dr. Zoldan invited Dr. Steven Abrams, chair of pediatrics at Dell Medical School, to present at her seminar series “The Doctor is in the House”. Dr. Abrams gave an energizing talk “Global Childhood Malnutrition: Engineering Solutions for Human Problems” to a packed seminar room. Throughout the talk, Dr. Abrams emphasized the need for engineers and doctors to collaborate on important unsolved engineering problems, ranging from incorporating rare metals into the diets of malnourished children to re-designing the milk dispensers of premature infants.