Next-generation aluminum adjuvants: Immunomodulatory layered double hydroxide NanoAlum reengineered from first-line drugs

Thymoquinone enhances efficacy of cervical Cancer therapeutic vaccines via modulating CD8+ T cells

Cervical cancer, primarily driven by persistent high-risk human papillomavirus (HPV) infection, remains a global health challenge. While therapeutic vaccines offer promising alternatives to conventional treatments, their clinical efficacy is often hindered by limitations in antigen presentation and the immunosuppressive tumor microenvironment (TME). In this study, we explore the potential of thymoquinone (TQ), a bioactive compound derived from Nigella sativa seeds, to enhance the efficacy of cervical cancer therapeutic vaccines. Utilizing a mouse cervical cancer xenograft model with TC-1 cells expressing HPV16 E6/E7 and ras genes, we observed substantial heterogeneity in vaccine-induced antitumor responses. Mice were stratified into hyporesponsiveness (Hypo) and hyperresponsiveness (Hyper) groups based on tumor progression. The Hyper group exhibited significantly reduced tumor growth, marked by increased CD4+ and CD8+ T cell infiltration, reduced regulatory T cells (Tregs), and altered systemic immune parameters. Metabolite profiling identified 63 differential metabolites, with TQ being notably upregulated in the Hyper group, correlating positively with CD4+ and CD8+ T cells and negatively with Tregs and tumor volume. Combining TQ with the vaccine potentiated antitumor responses, leading to smaller tumors without significant changes in body weight. Immunohistochemical and flow cytometry analyses revealed augmented CD4+ and CD8+ T cell infiltration and reduced Tregs, alongside increased IFN-γ production in the combination of vaccine with (Vax + TQ) group. RNA-Seq analysis of TQ-treated CD8+ T cells revealed upregulation of immune-related genes, including Spp1, Grem1, Cxcl10, Isg15, Lcn2, and Sema3c, highlighting enriched immune pathways. Furthermore, TQ treatment upregulated ISG15 expression and enhanced CD8+ T cell cytotoxicity and cytokine secretion both in vitro and in vivo. In conclusion, our findings suggest that TQ enhances the efficacy of cervical cancer therapeutic vaccines by modulating immune responses, particularly by upregulating ISG15 and boosting CD8+ T cell function. This study provides a theoretical foundation for TQ as a promising adjuvant in cancer immunotherapy.

Artificially tagging tumors with nano-aluminum adjuvant-tethered antigen mRNA recruits and activates antigen-specific cytotoxic T cells for enhanced cancer immunotherapy

T cell therapy for solid tumors faces significant challenges due to the immune off-target attack caused by the loss of tumor surface antigens and inactivation in acidic tumor microenvironment (TME). Herein, we developed a bifunctional immunomodulator (MO@NAL) by loading ovalbumin (OVA; model antigen) mRNA (mOVA) onto lysozyme-coated layered double hydroxide nano-aluminum adjuvant (NA). The NA's inherent alkalinity effectively neutralizes the excess acid within the TME and suppresses regulatory T cells, creating a favorable microenvironment to enhance cytotoxic T cell infiltration and activation in tumors. Particularly, once internalization by tumor cells, MO@NAL efficiently tags the tumor cell surface with OVA through the carried mOVA, providing targets for recruiting and directing the antigen-specific cytotoxic T cells to destroy tumor cells. In mice pre-vaccinated with the OVA vaccine, intratumoral administration of MO@NAL rapidly awakens OVA-specific immune memory, rapidly and effectively inhibiting the progression of colon tumors and melanoma at both early and advanced stages. In non-pre-vaccinated mice, combining MO@NAL with the OVA therapeutic vaccine or OVA-specific adoptive T cell transfusion similarly achieves robust solid tumor suppression. These findings thus underscore the potential of MO@NAL as an effective and safe immunomodulator for enhancing cytotoxic T cell responses and providing timely intervention in solid tumor progression.

Layered double hydroxides for regenerative nanomedicine and tissue engineering: recent advances and future perspectives

With the rapid development of nanotechnology, layered double hydroxides (LDHs) have attracted considerable attention in the biomedical field due to their highly tunable composition and structure, superior biocompatibility, multifunctional bioactivity, and exceptional drug delivery performance. However, a focused and comprehensive review addressing the role of LDHs specifically in tissue regeneration has been lacking. This review aims to fill that gap by providing a systematic and in-depth overview of recent advances in the application of LDHs across various regenerative domains, including bone repair, cartilage reconstruction, angiogenesis, wound healing, and nerve regeneration. Beyond presenting emerging applications, the review places particular emphasis on elucidating the underlying mechanisms through which LDHs exert their therapeutic effects. Although LDHs demonstrate considerable promise in regenerative medicine, their clinical translation remains in its infancy. To address this, we not only provided our insights into the personalized problems that arise in the application of various tissues, but also focused on discussing and prospecting the common challenges in the clinical translation of LDHs. These challenges include optimizing synthesis techniques, enhancing biosafety and stability, improving drug-loading efficiency, designing multifunctional composite materials, and establishing pathways that facilitate the transition from laboratory research to clinical practice.

Advancing cancer gene therapy: the emerging role of nanoparticle delivery systems

Gene therapy holds immense potential due to its ability to precisely target oncogenes, making it a promising strategy for cancer treatment. Advances in genetic science and bioinformatics have expanded the applications of gene delivery technologies beyond detection and diagnosis to potential therapeutic interventions. However, traditional gene therapy faces significant challenges, including limited therapeutic efficacy and the rapid degradation of genetic materials in vivo. To address these limitations, multifunctional nanoparticles have been engineered to encapsulate and protect genetic materials, enhancing their stability and therapeutic effectiveness. Nanoparticles are being extensively explored for their ability to deliver various genetic payloads-including plasmid DNA, messenger RNA, and small interfering RNA-directly to cancer cells. This review highlights key gene modulation strategies such as RNA interference, gene editing systems, and chimeric antigen receptor (CAR) technologies, alongside a diverse array of nanoscale delivery systems composed of polymers, lipids, and inorganic materials. These nanoparticle-based delivery platforms aim to improve targeted transport of genetic material into cancer cells, ultimately enhancing the efficacy of cancer therapies.

Animal vaccine revolution: Nanoparticle adjuvants open the future of vaccinology

In recent years, the rapid development of nanoparticle adjuvants has greatly facilitated the treatment and prevention of infectious diseases in humans and animals. The remarkable success of mRNA nanovaccines against SARS-CoV-2 has accelerated the advancement of nanoparticle adjuvant technologies in the era of precision medicine. Significant progress has been made in researching nanovaccines for major animal infectious diseases, such as porcine epidemic diarrhea, avian influenza, porcine reproductive and respiratory syndrome, bovine viral diarrhea, foot-and-mouth disease, African swine fever, and Newcastle disease. This article reviews the nanoparticle adjuvants under investigation for animal use, emphasizing their diverse mechanisms of action and immunological properties, and analyzes the physicochemical factors influencing their immune-enhancing effects. On this basis, we discuss future prospects and key challenges that need to be addressed, aiming to provide valuable references for the development of novel animal vaccine adjuvants.

Bioengineered ClearColi™-derived outer membrane vesicles displaying CT26 neoepitopes as potent vaccine adjuvants against colon carcinoma in a preventive mouse model

The mutation frequency of colorectal cancer, the third most diagnosed tumor worldwide, is usually very high. To simultaneously target several mutations, we previously designed a CT26 polytope containing neoepitopes and epitopes of the murine CT26 colon cancer cell line. Additionally, to overcome the low immunogenicity of the CT26 polytope vaccine, we isolated recombinant outer membrane vesicles (rOMVs) displaying CT26 polytope from ClearColi™ and found that they induce antitumor immunity. In light of our previous studies, in this study, the recombinant CT26 polytope was chosen as the antigen to investigate the role of ClearColi™-derived OMVs and rOMVs displaying the CT26 polytope as adjuvants against colorectal carcinoma. CT26 polytope vaccine alone and in combination with OMV, rOMV displaying CT26 polytope, and alum as adjuvants were administered to BALB/c mice. Then, the humoral immunity specific to CT26-M90 and CT26 polytope and the stimulated IFN-γ, TNF-α, IL-10, and granzyme B were evaluated. Furthermore, the preventive effect of different immunization strategies against CT26 cells was assessed. Herein, immunization with OMVs and, particularly, rOMVs as adjuvants in combination with CT26 polytope resulted in higher production of CT26 polytope- and CT26-M90 peptide-specific IgG2a antibodies, an indicator of potential Th1 response, and enhanced levels of IFN-γ and TNF-α compared to alum. Furthermore, rOMVs as adjuvants induced higher levels of granzyme B and protection against CT26 characterized by significant reduction of tumor size compared to alum as adjuvants. This study indicates the efficacy of rOMVs and OMVs as adjuvants in combination with the CT26 polytope in a preventive CT26 mouse model. rOMVs delivering polytopic antigens, including different neoepitopes and epitopes as adjuvants, can provide promising platforms for the development of personalized cancer vaccines and vaccines against diseases containing highly variable antigens.

Chiral Aluminum Oxyhydroxide Supraparticles as Adjuvants

Aluminum-based adjuvants dominate global vaccine formulations owing to their proven efficacy in humoral immunity induction. However, their inherent limitations in activating cellular immunity pose critical challenges for vaccine development. In this study, chiral flower-like aluminum oxyhydroxide (AlOOH) supraparticles (SPs) are synthesized via a one-pot hydrothermal method using cysteine (Cys) enantiomers as chiral ligands, achieving a g-factor of 0.004. L-AlOOH SPs (L-SPs) demonstrate significantly greater enhancement in dendritic cell (DC) maturation and antigen cross-presentation efficiency compared to D-AlOOH SPs (D-SPs), indicating its potential as an adjuvant. Mechanistic studies reveal that L-SPs enter DCs via Toll-like receptor 2 (TLR2), thereby enhancing NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation. In vivo experiments show that L-SPs generate 21.59-fold higher OVA-specific antibody titers than commercial aluminum adjuvants. Further studies show that L-SPs, after mixed with H9N2 virus proteins, enhance influenza virus antibody titers by 15.28-fold, with sustained protection, confirming its translational potential. This study demonstrates the performance of chiral AlOOH SPs to simultaneously amplify humoral and cellular immunological responses, entering it as a promising next-generation adjuvant for cancer immunotherapy and pandemic preparedness.

Glycoside-Mediated Enhancement of Stability in Aluminum Oxyhydroxide Nanoadjuvants during Freeze-Drying

Aluminum-based adjuvants have been indispensable to vaccine potency. However, their effectiveness is difficult to maintain after freeze-drying, which limits the storage and application of aluminum-adjuvanted vaccines. In this study, the impact of freeze-drying on aluminum oxyhydroxide nanorods (AlOOH NRs) was investigated. Freeze-drying led to aggregation and resulted in the loss of the surface hydroxyl content of aluminum adjuvants. To alleviate freeze-drying-induced damage, the potency of different alkyl glycosides as protectants was further evaluated. It was demonstrated that the structural balance of the head and tail of a glycoside was more conducive to protecting AlOOH NRs from aggregation and loss of surface hydroxyl groups. These results underline the proper selection of protectants to protect adjuvants against functional defects caused by freeze-drying, which is important for the stability and efficacy of vaccines and biopharmaceutical products.