Non-Hodgkin Lymphoma (NHL) is one of the more common cancer subtypes in the United States, making up 4% of all cancers nationwide. The American Cancer Society estimates there will be approximately 82,000 new diagnoses and over 20,000 deaths in 2021. Some of the most common subtypes of NHL, Diffuse Large B-Cell Lymphoma (DLBCL) and Burkitt’s lymphoma, are particularly aggressive and accounts for nearly 30% of all NHL diagnoses. One of the more common systemic chemotherapeutic regimens for NHL is R-CHOP, which consists of an anti-CD20 antibody, a corticosteroid, and several potent chemotherapeutic drugs. There are a number of unfavorable side effects associated with this treatment regimen, such as alopecia, nausea, fatigue, and long-term cardiotoxicity due to the off-target effects of doxorubicin. Despite CHOP-based therapies having a success rate of 50% - 70% for DLBCL patients and Burkitt’s Lymphoma patients, approximately 20% of patients experience primary refractory disease and 30% of patients in complete remission will relapse. Recently, a novel peptide therapeutic (Tat-POSH) has been fabricated into peptide amphiphile micelles (PAMs) which have been shown to kill Burkitt’s Lymphoma cells. Previous work has shown the benefits of using environmentally-sensitive linkers, such as disulfide bridges and enzymatically-sensitive sequences for intracellular drug delivery. Using HBTU-mediated coupling of fmoc-protected amino acids, we have synthesized Tat-POSH peptide amphiphiles (PAs) with environmentally-sensitive regions coupling the therapeutic peptide and lipid moeities to assist with intracellular release, verifying structure using analytical mass spectrometry (MS). The Tat-POSH PAs were then purified using reverse-phase MS-controlled high pressure liquid chromatography (LC-MS) with a mobile phase of acetonitrile and 0.1% TFA ddH2O. Using the evaporation method, Tat-POSH PAs formed micelles (i.e., PAMs) which were further characterized for surface charge, size, and shape by employing transmission electron microscopy (TEM), zeta potential, and dynamic light scattering (DLS), respectively. Dissociation kinetics of the environmentally-sensitive linker were measured by the coupling fluorophores, 6-carboxytetramethylrhodamine (TAMRA) and 6-carboxyfluorescein (FAM), to additional lysines adjacent to the cleavage site and using Forster Resonance Energy Transfer (FRET) to assess the proximity of the two fluorophores.

Environmentally sensitive linkers for lymphoma targeted drug delivery

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.