BIOMED PhD Research Proposal 

Title: 
Engineering Durable Antigen-Specific (AS) Immune Tolerance via Push/Pull Immunomodulation of Dendritic Cells

Speaker:
Sihan Jia, PhD Candidate
School of Biomedical Engineering, Science and Health Systems
Drexel University

Advisor:
Peter Deak, PhD
Assistant Professor
Department of Chemical and Biological Engineering
College of Engineering
Drexel University 

Details:
Autoimmune and inflammatory diseases arise when dendritic cells (DCs) drive antigen-specific effector responses rather than tolerance. Current tolerogenic DC strategies are limited by incomplete, unstable reprogramming and off-target immunosuppression. This proposal develops a Push/Pull Immunomodulation (PPI) platform that simultaneously suppresses pro-inflammatory activation (“push”) and reinforces tolerogenic, regulatory programming (“pull”) in DCs to induce durable, antigen-specific tolerance.

Using a high-throughput screen of 40,833 immunomodulator/PRR-agonist combinations, we identified lead PPI formulations that maximize the IL-10/TNF-α ratio and engage tolerogenic checkpoints, including PD-L1 and BTLA, as well as the tryptophan-kynurenine-AhR axis. These leads are validated in human monocyte-derived DCs against clinical comparators and delivered via PLGA microparticles and lymph-node-targeting liposomes to confirm antigen-specific regulatory T-cell induction, in vivo persistence, and trafficking. The central proposed aim tests whether antigen-loaded PPI-DCs establish durable, antigen-specific tolerance in vivo using the MOG35-55 experimental autoimmune encephalomyelitis model, assessing clinical protection, antigen-specific Treg induction, and bystander specificity.

Together, this work defines a generalizable, biomaterial-enabled approach to engineering long-lived antigen-specific immune tolerance.

Faculty, staff, and students are invited to join the PHASES Data Core (Reneé Moore, PhD, Daniel Vader, PhD, Jonas Ventimiglia, MS, and Jamie Reese, MPA) for open discussions on working with electronic health records, Medicare and Medicaid, and location-based data.

Looking for new data sources? Faculty, staff, and students are invited to join the PHASES Data Core (Reneé Moore, PhD, Daniel Vader, PhD, Jonas Ventimiglia, MS, and Jamie Reese, MPA) for open discussions on working with electronic health records, Medicare and Medicaid, and location-based data. From first projects to established research, healthcare and location data can lead to new discoveries and better research. Questions, works in progress, brainstorming ideas, and problem solving are all welcome! Please register for one or more of the sessions being offered on June 16th. Session 1: Designing and conducting studies using electronic health records and Medicare/ Medicaid claims data from 11:00-12:00 Session 2: Using location information to contextualize study data from 2:00-3:00

BIOMED PhD Thesis Defense

Title: 
Predicting Dementia from Spontaneous Speech Using Large Language Models

Speaker: 
Felix Agbavor, PhD Candidate
School of Biomedical Engineering, Science and Health Systems
Drexel University

Advisor:
Hualou Liang, PhD
Professor
School of Biomedical Engineering, Science and Health Systems
Drexel University

Details:
Alzheimer’s disease (AD) and related cognitive disorders are typically diagnosed using clinical assessments that can be costly, time-intensive, and difficult to scale for frequent monitoring. Speech provides a practical alternative because it is natural, non-invasive, inexpensive to collect, and closely coupled to cognition. This dissertation investigates how foundation-model representations can improve speech-based cognitive impairment prediction while addressing two major barriers to deployment: limited generalization beyond English and brittleness under single-modality reliance.

The dissertation develops and evaluates three complementary contributions. First, it establishes speech-only foundations for both diagnostic prediction and severity estimation. Using transcript-first modeling, large language model (LLM) embeddings extracted from spontaneous speech transcripts support accurate AD classification and cognitive score prediction, outperforming conventional handcrafted feature baselines. Using end-to-end voice modeling, self-supervised speech representations enable direct waveform-to-prediction modeling with strong discrimination and stable performance under external validation, while supporting calibrated probability outputs suitable for screening-style interpretation.

Second, the dissertation treats multilingual robustness as a first-class objective. Using the TAUKADIAL bilingual setting (English and Mandarin Chinese), it evaluates language-agnostic versus language-specific strategies built on multilingual speech embeddings. Results show that strong bilingual performance benefits from language-specific modeling and task-aware aggregation across multiple picture-description prompts, while cross-language transfer remains challenging under distribution shift.

Third, the dissertation extends beyond speech-only modeling to multimodal picture-description screening. It proposes an embedding-level fusion framework that integrates text, audio, and the shared image stimulus using cross-attention, and it evaluates unimodal, bimodal, and trimodal configurations under a unified protocol. The fusion results demonstrate that multimodal integration improves dementia prediction beyond unimodal baselines and clarifies how each modality contributes, with language content providing the dominant signal and audio and image providing complementary gains.

Overall, this dissertation demonstrates that foundation-model embeddings provide an effective backbone for scalable cognitive impairment screening from speech, but that trustworthy deployment requires explicit attention to multilingual generalization, robustness, and interpretability.

This workshop will provide a brief overview of NSF GRFP application components, then walk you through reflection and planning exercises to help you map out your application process.

This is the first of four biweekly summer workshops on the NSF GRFP; applicants are also encouraged to participate in our grad fellowships biweekly writing group. You can learn more about these events and review materials from previous info sessions and workshops on our NSF Applicant Resource Site (Drexel login required).

The National Science Foundation’s Graduate Research Fellowship Program (GRFP) provides selected fellows with three years of funding, including a living stipend and tuition funds, to support a research-focused doctoral degree in STEM, social sciences, or STEM education. The current application cycle is open to US citizens and permanent residents planning to begin their first graduate program in Fall 2027, or who will be in the 1st year of a PhD program in Fall 2026. BS-MS students planning to continue on to a PhD program are only eligible to apply in their final year of BS-MS study (and not as first year doctoral students).

Register on Zoom to attend

Need help with your résumé? This is the perfect time to ask your questions! Meet with Ken Bohrer, Senior Career Counselor, in person at the Office of Graduate Studies.

Register on Handshake:https://drexel.joinhandshake.com/edu/events/1954962

BIOMED PhD Thesis Defense

Title: 
Development of a Geometrically Tunable Cardiovascular Shunt for Pediatric Heart Reconstruction

Speaker: 
Akari Seiner, PhD Candidate
School of Biomedical Engineering, Science and Health Systems
Drexel University

Advisor:
Christopher Rodell, PhD
Associate Professor
School of Biomedical Engineering, Science and Health Systems
Drexel University

Details:
Congenital heart defects (CHDs) are the most common class of birth anomalies, affecting approximately 1% of live births globally and representing a leading cause of infant morbidity and mortality worldwide. A critical subset, collectively termed single ventricle (SV) defects, are characterized by the functional or morphological inadequacy of one ventricle, leaving a single dominant ventricle to simultaneously support both pulmonary and systemic circulations. Among these, hypoplastic left heart syndrome (HLHS) is the most prevalent and severe, accounting for 25 – 40% of all neonatal cardiac deaths. Without surgical intervention, SV defects are universally fatal. The current standard of care is staged palliative reconstruction, the Norwood–Glenn–Fontan procedure, in which the initial Norwood procedure establishes parallel circulation via implantation of a fixed-diameter modified Blalock–Taussig–Thomas (mBTT) shunt. Despite decades of iterative refinement of surgical procedures and post-operative care, interstage mortality remains as high as 39%, with nearly 48% of patients requiring invasive shunt revision due to the device's inability to accommodate the rapid somatic growth of the developing infant. These persistent limitations motivate the development of a geometrically adaptive shunt capable of dynamically adjusting its lumen diameter without reoperation.

To address these limitations, this work develops a geometrically tunable cardiovascular shunt for pediatric heart reconstruction. Photoresponsive methacrylated dextran (DexMA) hydrogels were synthesized and integrated as luminal linings within polytetrafluoroethylene (PTFE) and expanded PTFE (ePTFE) shunt conduits. A dual-stage crosslinking strategy — combining covalent Michael addition crosslinking with a secondary blue-light photopolymerization step — was established to achieve controlled volumetric contraction of the hydrogel lining upon irradiation, thereby expanding the inner lumen diameter. Systematic investigation of polymer modification, concentration, and dithiothreitol (DTT)-to-methacrylate molar ratios yielded an optimized formulation of 50% modified DexMA at 10%w/v with a 40% DTT/methacrylate ratio. With this formulation, volume changes exceeding 39% were achieved, enabling clinically relevant increases in lumen diameter. Building on this material platform, comprehensive biological safety was established in accordance with ASTM and ISO standards. Hydrogels exhibited excellent long-term hydrolytic stability (> 3 months), cytocompatibility (including both 3T3 fibroblast and HUVEC cell lines), lack of immune response (RAW264.7 cells, primary human PBMCs), and hemocompatibility (absence of complement activation, platelet aggregation, or hemolysis) across hydrogel formulations, collectively demonstrating the platform's suitability for a blood-contacting vascular environment.

The hydrogel platform was integrated into full-scale shunt prototypes using polydopamine (PDA)-mediated surface functionalization to ensure robust hydrogel-to-PTFE interfacial bonding. Incremental exposure to catheter-delivered blue light via a fiber-optic radial diffuser produced precise lumen diameter expansion up to 40%. Programmable expansion patterns, including incremental weekly increases and one-time targeted adjustments, remained structurally stable over one month. These results were subsequently translated to clinical-grade ePTFE, where comprehensive multi-axial mechanical characterization demonstrated dimensional stability under physiological arterial pressures up to 160 mmHg, and light-activated expansion in ePTFE was statistically equivalent to that achieved in rigid PTFE prototypes.

Evaluation of the tunable shunt under simulated physiological flow conditions was performed using ASTM F1841-19 compliant dynamic hemocompatibility testing and an ex vivo perfusion platform. Dynamic hemocompatibility confirmed that the hydrogel lining does not introduce additional hemolytic shear compared to controls. Hemodynamic perfusion testing over a flow range of 300 – 1000 mL/min demonstrated a highly linear pressure-flow relationship (R² = 0.99), consistent with the physiological range of neonatal cardiac output. Non-invasive nanoCT imaging of shunts before and after flow exposure confirmed structural integrity and dimensional stability of the inner lumen, with no significant differences in lumen diameter or circularity. Together, these findings establish proof-of-concept for a light-responsive, geometrically tunable cardiovascular shunt capable of accommodating infant growth through minimally invasive catheter-based actuation, offering a promising strategy to reduce interstage mortality and reintervention burden in pediatric SV palliation.

As international students prepare to travel to and begin their graduate study in the US, the Office of Graduate Studies of Drexel University is committed to helping make the transition as smooth as possible. The Office of Graduate Studies, in partnership with the International Graduate Student Association (IGSA) and campus partners, hosts a series of optional but highly encouraged pre-arrival webinars over the summer to help incoming international graduate students prepare for graduate study in the US, arrival to and life in the US and Philadelphia, and to answer any questions about student life and graduate study at Drexel.

The webinars include:

-A welcome and introduction by members of the Office of Graduate Studies, International Students and Scholars Services (ISSS), Counseling and Health Services, the Steinbright Career Development Center (SCDC), Drexel Central, and members of the International Graduate Student Association (IGSA);
-A comprehensive overview of life in the US, in Philadelphia, and at Drexel, advice on what to bring and how to prepare for your arrival in the US, and how to prepare for graduate and academic study at Drexel;
-A Question & Answer (Q&A) session featuring current international graduate students, professional staff members to answer questions about immigration requirements, health insurance, immunizations, billing, co-op and career services, and a wide range of other topics!

Join the Zoom

This workshop will provide a deep dive into the NSF GRFP Research Statement. It is helpful for attendees to have a research direction in mind, but applicants at all stages will benefit from attending.

This is the second of four biweekly summer workshops on the NSF GRFP; applicants are also encouraged to participate in our grad fellowships biweekly writing group. You can learn more about these events and review materials from previous info sessions and workshops on our NSF Applicant Resource Site (Drexel login required).

The National Science Foundation’s Graduate Research Fellowship Program (GRFP) provides selected fellows with three years of funding, including a living stipend and tuition funds, to support a research-focused doctoral degree in STEM, social sciences, or STEM education. The current application cycle is open to US citizens and permanent residents planning to begin their first graduate program in Fall 2027, or who will be in the 1st year of a PhD program in Fall 2026. BS-MS students planning to continue on to a PhD program are only eligible to apply in their final year of BS-MS study (and not as first year doctoral students).

Register on Zoom to attend