El-Ghlban, S. | bioRxiv Science

bioRxiv2025

Enhanced Wound Healing and Anti-Inflammatory Effects of Vitamin C-Loaded Hyaluronic Acid/Collagen Scaffolds in Preclinical Rat Models

Wound healing is a complex biological process critical for restoring skin integrity after injury. However, chronic wounds present significant clinical challenges due to persistent inflammation, disrupted collagen synthesis, and susceptibility to infection. Bioactive scaffolds have emerged as promising therapeutic strategies to enhance tissue regeneration by modulating cellular behavior and extracellular matrix (ECM) dynamics. This study explores a hyaluronic acid-collagen (HyCol) scaffold enriched with vitamin C (VC), producing (VC-HyCol) to improve wound healing in preclinical rat models. Hyaluronic acid and collagen, key ECM components, provide structural and biochemical support, while vitamin C acts as both a collagen biosynthesis cofactor and an antioxidant to counteract oxidative stress. The scaffold was designed to emulate the native ECM microenvironment, facilitating fibroblast proliferation, keratinocyte migration, and angiogenesis. Physicochemical characterization, biocompatibility assessments, and in vivo wound healing experiments were performed to evaluate its therapeutic efficacy. Results demonstrated that the incorporation of vitamin C significantly enhanced fibroblast activity, reduced inflammatory markers, and accelerated tissue regeneration compared to control groups. Histological and molecular analyses further confirmed enhanced collagen deposition and neovascularization, indicating faster and more organized wound repair. These findings highlight the potential of this multifunctional scaffold as an advanced wound dressing, with significant implications for regenerative medicine and clinical wound management. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=116 SRC="FIGDIR/small/665568v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@d8d248org.highwire.dtl.DTLVardef@d58e05org.highwire.dtl.DTLVardef@5f210eorg.highwire.dtl.DTLVardef@17354b1_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2025

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

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

immunology↗