Sebnem Ercelen Ceylan
University of Health Sciences, Hamidiye,
Turkey
Abstract Title: Advancing Vaccine Technology: Development of a Hydrogel-Based Adjuvant for Enhanced Immunogenicity and Biocompatibility
Biography: Sebnem Erçelen Ceylan is a faculty member at the Department of Biophysics, University of Health Sciences. She has extensive experience as a project manager and researcher in national and international scientific projects, particularly in drug delivery systems and vaccine adjuvants. Her research focuses on drug carrier nanosystems, including antigen delivery, and the biophysical characterization and physicochemical stability of vaccine adjuvant formulations. She is currently the Principal Investigator of a NATO Science for Peace and Security Program–funded project on hydrogel-based vaccine adjuvants. Her work contributes significantly to biophysics, nanomedicine, and immunology, supporting the advancement of vaccine technologies for global health.
Research Interest: Adjuvants play a crucial role in enhancing immune responses by improving antigen presentation and immunogenicity. In this study, the adjuvant potential of the newly synthesized 3D cross-linked porous anionic hydrogel particles (HG-5), sized in the range of 200 nm. HG-5 was evaluated. Combining hydrophobic fragments and hydrophilic carboxylic groups in the structure provides its dispersibility in water at a 7.2 – 7.4 pH value. BSA was used as a model antigen for adjuvant loading. The antigen-binding capacity of the newly synthesized adjuvant was determined by BCA and SDS-PAGE assays. The BSA loading capacity of the adjuvants was determined to be 50% by evaluating various parameters, including temperature, incubation time, and mixing conditions. Dynamic Light Scattering (DLS) analysis determined that HG-5 has a size of 200 nm, with a polydispersity index (PDI) of 0.15. Hemolytic activity assays demonstrated no detectable hemolysis even at the highest concentration of HG-5 (25 mg/mL). The viscosity of the adjuvant was analyzed in addition to the evaluation of the RBC rheology after HG-5 incubation to assess its potential influence on blood flow dynamics. The effect of HG-5 on DNA stability and mitochondrial integrity in normal cells was evaluated. No evidence of DNA condensation, fragmentation, or single-strand breaks was observed following the adjuvant treatment. Additionally, HG-5 did not induce mitochondrial dysfunction. In vivo evaluations were conducted using BALB/c mice administered HG-5 at two doses: 800 µg/mouse (40 mg/kg) and 8 mg/mouse (400 mg/kg). HG-5 demonstrated low toxicity, with no significant changes in organ weight. Subcutaneous administration of HG-5 over 28 days resulted in no adverse effects, allergic reactions, weight loss, or mortality. Notably, a significant increase in specific antibodies against BSA was detected in HG-5-immunized mice compared to the control group. These results demonstrate that HG-5 has adjuvant properties favourable for safe and effective vaccine development.