CBEE Seminar: Marwa El-Sayed and Michael Zhang

The formation of secondary organic aerosols through aqueous processes (aqSOA) has been identified as an important route in forming organic aerosols; however, many aspects of aqSOA formation are still uncertain. The aim of this ambient study was to characterize the reversible and irreversible formation of aqSOA across the four seasons to provide insight into the main factors which govern the uptake of organic gases into aerosol liquid water. The reversible and irreversible uptake of water-soluble organic gases in liquid water was measured in Baltimore, MD using a recently developed on-line method. Not only did the amount of aqSOA vary across the seasons, but also there were strong seasonal differences in the reversible and irreversible nature of the uptake of gases into liquid water. Based on the seasonal differences observed in aqSOA formation, some of the factors underlying the differences in the concentrations of reversible and irreversible aqSOA were investigated, which include: temperature, RH, precursor VOC emissions, mixing and transport. 

Michael Zhang 

Cell Membrane-Inserting Amphiphilic Bioconjugates for Enhancing Immunotherapies in Cancer 

In cancer immunotherapy, adoptive cell transfer (ACT) expands cells of interest ex vivo and re-infuses them into patients; despite studies suggesting ACT as a durable cure for diseases, the laborious process of ex vivo cell manipulation has made implementing ACT challenging in the clinic. Recently, amphiphilic molecules (amph-molecules) were engineered as a vaccine by coupling known antigen (Ag) and adjuvant (Av) molecules to lipid tails, forming stable bioconjugates that spontaneously traffic to lymph nodes to enhance endogenous immune responses. Using this approach, we show that amph-peptide Ags and amph-toll like receptor ligands (TLRL) rapidly insert into Band T-cell plasma membranes, functionalizing immune cells to 1) efficiently present Ag to Agspecific T-cells for vaccine applications, 2) activate immune cells by paracrine Av signaling, and 3) promote expansion/function of tumor-specific T-cells by autocrine Av signaling to improve therapeutic efficacy.