bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2025.04.04.647265

High-integrity nanoemulsions formulation of resiquimod (R848) enhances stability and delivery for triple negative breast cancer immunotherapy

Salem, A.·Attia, S.·El-Ghlban, S.·Montaser, A. S.·Abdelhameed, M. F.·Helmy, M. W.·Attia, M. F.
View original source ↗Export metadata ↓

Abstract

Triple-negative breast cancer (TNBC) poses significant clinical challenges due to its high heterogeneity, with multiple subtypes exhibiting distinct molecular characteristics and treatment responses. The development of resistance to chemotherapy and targeted therapies remains a major obstacle, and identifying reliable biomarkers to predict therapeutic response continues to be challenging. This study aims to enhance the delivery of the immunostimulant Toll-like receptor 7/8 (TLR7/8) agonist resiquimod (R848) using a safe and highly integrated nanoemulsions (NEs) formulation, providing effective and reliable immunotherapy. A series of NEs were prepared and optimized with and without the reactive lipophilic compound ricinoleic acid. Neutral and negatively charged NE formulations encapsulating R848 were compared. The physicochemical properties and in vitro delivery of resiquimod into RAW 264.7 macrophages and 4T1 TNBC cell line models were studied. Both R848-loaded NE formulations exhibited prolonged shelf-life stability with minimal protein binding. Incorporating small portions of ricinoleic acid into the formulation (negatively charged NEs) slowed drug release and improved physical properties and overall delivery compared to ricinoleic-free formulations, likely due to its interaction with the drug. Cytotoxicity and cellular uptake studies were conducted on both NE models, showing localization in the macrophage cell membrane and 4T1 cell cytoplasm. Molecular profiling in 4T1 cells revealed R848-NEs modulated key biomarkers (TLR4/7, Cyclin D1, NF-{kappa}B) while potently inducing autophagy (evidenced by LC3II/p62/Beclin-1 alterations) and PD-L1 upregulation. These dual effects--autophagy-mediated tumor suppression and immune checkpoint modulation--suggest therapeutic synergy between R848-NEs and anti-PD-L1 antibodies, presenting a promising combinatorial strategy for TNBC treatment. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=72 SRC="FIGDIR/small/647265v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@d4daceorg.highwire.dtl.DTLVardef@692daforg.highwire.dtl.DTLVardef@13676d7org.highwire.dtl.DTLVardef@b449fc_HPS_FORMAT_FIGEXP M_FIG C_FIG

Explore related subjects

immunologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Salem, A., Attia, S., El-Ghlban, S., Montaser, A. S., Abdelhameed, M. F., Helmy, M. W., Attia, M. F.. 2025-04-09. High-integrity nanoemulsions formulation of resiquimod (R848) enhances stability and delivery for triple negative breast cancer immunotherapy. https://doi.org/10.1101/2025.04.04.647265

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Common viral infections seed regionally distinct resident memory T cells in the human CNS

T cells persist in the central nervous system (CNS) and can drive both protection and neurological disease. How these cells are organized in humans and what they recognize is largely unknown. Here, we profiled CD8 T cells across anatomically distinct CNS regions, obtained through on-site autopsies and temporal lobe resection surgeries, using single-cell RNA sequencing, paired T cell receptor sequencing, and DNA-barcoded tetramers. Resident memory T cells (TRM) specific for Epstein-Barr virus, cytomegalovirus, influenza A, and SARS-CoV-2 were identified across CNS compartments. Anatomical location was the strongest correlate of TRM cell state, with leptomeningeal cells adopting a cytokine-poised TRM program, whereas brain TRM cells were transcriptionally restrained. Cells of the same clonotype spanned tissues yet adopted local transcriptional states. Viral specificity added another layer of TRM heterogeneity with GZMK/GZMA-expressing EBV-specific populations and interferon-stimulated gene signatures in SARS-CoV-2 and Influenza A-specific cells. The human CNS thus harbors regionally distinct CD8+ TRM shaped by common viral exposures.

immunology↗
bioRxiv2026

A regulatory T cell signature provides a shared molecular basis for the therapeutic window of opportunity in rheumatic disease

Rheumatic diseases, including rheumatoid arthritis (RA), spondyloarthritis (SpA) and osteoarthritis (OA), show distinct phenotypes yet respond to overlapping therapies, implicating shared immune mechanisms. In the Transimmunom cohort, we profiled peripheral blood from 240 individuals (47 healthy, 44 OA, 91 RA, 58 SpA) across deep immunophenotyping, immunoproteomics and Treg-Teff transcriptomics. Single-layer analyses revealed broader Treg than Teff remodeling, along with a shared pattern of reduced activated Tregs and expanded Helios+ Tregs across all diseases, alongside a decrease in functional Treg subpopulations, including CTLA4+ and CD45RA- Tregs. In RA specifically, LAG3+ Tregs were also expanded. Combining omics layers outperformed single-layer approaches for disease classification. Among individual layers, Treg transcriptomes were most discriminative, and integration uncovered disease-specific programs. Unsupervised clustering identified a cross-disease cluster independent of activity, treatment and age, mapping to early disease (<= years) and dominated by a Treg dysfunction-associated program. These results provide a biological rationale for the therapeutic "window of opportunity" concept and duration-stratified Treg-directed trials.

immunology↗
bioRxiv2026

Inhibitory Fc Receptor sets a time limit on macrophage response to IgG

Antibodies engage both activating Fc Receptors and the inhibitory receptor Fc{gamma}RIIB. Why macrophages need a dedicated inhibitory receptor rather than simply tuning activating receptor signaling is unclear. Using DNA-based chimeric receptors and in silico modeling, we independently controlled activating and inhibitory Fc Receptors. We found that Fc{gamma}RIIB imposed a time limit on macrophage phagocytosis and ERK signaling. The time limit is due to activating Fc Receptors converting PI(4,5)P2 to PI(3,4,5)P3, which is subsequently converted to PI(3,4)P2 by Fc{gamma}RIIB. This leads to a pulse of active signaling, which is sufficient for phagocytosis of small bacteria-sized targets but not phagocytosis of large targets and TNF secretion. Unlike engaging Fc{gamma}RIIB, reducing activating Fc Receptor signaling decreased initiation of phagocytosis, the speed of PI(3,4,5)P3 generation, and the amplitude of ERK signaling. Our results demonstrate that Fc{gamma}RIIB controls the duration of IgG signaling, while the activating Fc Receptors control sensitivity.

immunology↗