Modularized viromimetic polymer nanoparticle vaccines (VPNVaxs) to elicit durable and effective humoral immune responses

Tuning Surface Valences of Nanoengagers to Enhance Their Structural Advantages for Efficiently Redirecting T Cells against Solid Tumors

The nanoengager strategy, which enhances receptor signaling responsiveness through a multivalent ligand binding mode, offers a promising approach for improving immune cell redirecting therapy. Increasing nanomaterial platforms have been developed for constructing more flexible and multifunctional nanoengagers, but the different mediating mechanisms from their multivalent nanostructures, compared to original monomolecule engagers, have rarely been discussed. Here, we constructed dual-specificity T cell nanoengagers (TNEs) targeting CD3 and PDL1 receptors based on a polyethylene glycol-b-polylactic acid (PEG-b-PLA)-assembled nanoparticle and specifically studied the impact of surface antibody valences on their functional mechanisms, thereby enhancing the structural advantages of TNEs against solid tumors. Major conclusions include the following: (1) Valence control of surface antibodies is crucial for ensuring the safety and efficacy of TNEs when redirecting T cells. (2) Tuning the valence ratios of the two antibodies with the respective targeting is essential for enhancing the tumor-targeting capability and overall antitumor efficacy of TNEs, while TNE with a valence ratio of anti-CD3 to anti-PDL1 of 25:50 demonstrated the best performance. (3) Compared to monovalent soluble engager molecules, TNEs with an optimized surface multivalent antibody structure can effectively promote the enrichment of peripheral T cells into solid tumor sites and improve the tumor immune microenvironment. These results demonstrate the importance of optimizing the surface antibody valences to enhance the structural advantages of the TNE and would benefit the design and application of nanoparticle-based engagers, especially for TNEs.

Coagulation-Targeted TGF-β Signaling Pathway Inhibitor Nanomedicine for Inhibiting the Growth and Lung Metastasis of Breast Cancer

The transforming growth factor β (TGF-β) signaling pathway exerts a dual role in oncogenesis, acting as a suppressor in healthy and early stage neoplastic tissues while promoting malignancy and metastasis in advanced cancers. Tumor hemorrhage further exacerbates TGF-β-mediated metastasis by up-regulating its expression. Here, a coagulation-targeting peptide (A15)-decorated TGF-β inhibitor nanomedicine (A15-LY-NPs) was developed. The tumor colonization assays showed that the nanomedicine reduced 4T1-luc cell colonization in normal tissues. When combined with a vascular disrupting agent, A15-LY-NPs demonstrated three times greater drug accumulation in the tumor at 24 h compared to the control and showed a 93.7% tumor suppression rate in 4T1 tumors initiated at ∼500 mm3, significantly attenuating metastatic spread to the lungs and liver. This study presents an innovative approach for the precise and efficient delivery of TGF-β inhibitors to tumors, offering the potential to augment the efficacy of cancer therapeutics.

Chiral nanomaterials as vaccine adjuvants: a new horizon in immunotherapy

Chiral nanomaterials are emerging as a promising class of vaccine adjuvants with the potential to significantly enhance vaccine efficacy, especially in the context of cancer immunotherapy. These nanomaterials can trigger enantioselective immune responses, enabling more precise and efficient vaccines. Their distinctive optical, electronic, and catalytic characteristics, along with the ability to be engineered with specific physical and chemical properties, make them highly suitable for next-generation vaccines development. Chiral nanomaterials can enhance antigen presentation, modulate the tumor microenvironment, and boost the efficacy of immune responses, particularly against complex diseases such as cancer. Nevertheless, significant challenges remain, such as ensuring the reproducibility of their synthesis, conducting thorough safety assessments, and gaining a deeper understanding of their interactions with the immune system. Continued research and development are crucial to unlocking the potential of chiral nanomaterials in vaccine technology, thus paving the way for more effective, targeted, and personalized immunotherapies.

Fluoroamphiphiles for enhancing immune response of subunit vaccine against SARS-CoV-2

In recent decades, protein-based therapy has garnered valid attention for treating infectious diseases, genetic disorders, cancer, and other clinical requirements. However, preserving protein-based drugs against degradation and denaturation during processing, storage, and delivery poses a formidable challenge. Herein, we designed a novel fluoroamphiphiles polymer to deliver protein. Two different formulations of nanoparticles, cross-linked (CNP) and micelle (MNP) polymer, were prepared rationally by disulfide cross-linked and thin-film hydration techniques, respectively. The size, zeta potential, and morphology of both formulations were characterized and the delivery efficacy of both in vitro and in vivo was also assessed. The in vitro findings demonstrated that both formulations effectively facilitated protein delivery into various cell lines. Moreover, in vivo experiments revealed that intramuscular administration of the two formulations loaded with a SARS-CoV-2 recombinant receptor-binding domain (RBD) vaccine induced robust antibody responses in mice without adding another adjuvant. These results highlight the potential use of our carrier system as a safe and effective platform for the in vivo delivery of subunit vaccines.

Preparation of viromimetic rod-like nanoparticle vaccines (RLNVax) and study of their humoral immune activation efficacy

Virus-like nanoparticle vaccines can efficiently activate the humoral immune response by cross-linking B cell receptors with their surface multivalent antigen arrays. This structurally dependent mechanism makes it crucial to regulate and optimize structural parameters to enhance the efficacy of nanoparticle vaccines. In this study, we prepared nanoparticle vaccines with different aspect ratios by chemically modifying antigen proteins onto the surfaces of poly(amino acid) nanoparticles of various shapes (spherical, ellipsoidal, and rod-like). This allowed us to investigate the impact of structural anisotropy on the humoral immune activation efficacy of nanoparticle vaccines. Furthermore, the end-group molecules of poly(amino acid) materials possess aggregation-induced emission (AIE) properties, which facilitate monitoring the dynamics of nano-assemblies within the body. Results showed that rod-like nanoparticle vaccines (RLNVax) with a higher aspect ratio (AR = 5) exhibited greater lymph node draining efficiency and could elicit more effective B cell activation compared to conventional isotropic spherical nanoparticle vaccines. In a murine subcutaneous immunization model using ovalbumin (OVA) as a model antigen, RLNVax elicited antigen-specific antibody titers that were about 64 times and 4.6 times higher than those induced by free antigen proteins and spherical nanoparticle vaccines, respectively. Additionally, when combined with an aluminum adjuvant, antibody titers elicited by RLNVax were further enhanced by 4-fold. These findings indicate that the anisotropic rod-like structure is advantageous for improving the humoral immune activation efficacy of nanoparticle vaccines, providing significant insights for the design and optimization of next-generation nanoparticle vaccines.

Dynamic Covalent Hydrogel as a Single-Dose Vaccine Adjuvant for Sustained Antigen Release and Significantly Elevated Humoral Immunity

Vaccine is the most important way for fighting against infection diseases. However, multiple injections and unsatisfied immune responses are the main obstacles for current vaccine application. Herein, a dynamic covalent hydrogel (DCH) is used as a single-dose vaccine adjuvant for eliciting robust and sustained humoral immunity. By adjusting the mass ratio of the DCH gel, 10-30 d constant release of the loaded recombinant protein antigens is successfully realized, and it is proved that sustained release of antigens can significantly improve the vaccine efficacy. When loading SARS-CoV-2 RBD (Wuhan and Omicron BA.1 strains) antigens into this DCH gel, an over 32 000 times and 8000 times improvement is observed in antigen-specific antibody titers compared to conventional Aluminum adjuvanted vaccines. The universality of this DCH gel adjuvant is confirmed in a Nipah G antigen test as well as a H1N1 influenza virus antigen test, with much improved protection of C57BL/6 mice against H1N1 virus infection than conventional Aluminum adjuvanted vaccines. This sustainably released, single-dose DCH gel adjuvant provides a new promising option for designing next-generation infection vaccines.

Functionally Designed Nanovaccines against SARS-CoV-2 and Its Variants

COVID-19, generated by SARS-CoV-2, has significantly affected healthcare systems worldwide. The epidemic has highlighted the urgent need for vaccine development. Besides the conventional vaccination models, which include live-attenuated, recombinant protein, and inactivated vaccines, nanovaccines present a distinct opportunity to progress vaccine research and offer convenient alternatives. This review highlights the many widely used nanoparticle vaccine vectors, outlines their benefits and drawbacks, and examines recent developments in nanoparticle vaccines to prevent SARS-CoV-2. It also offers a thorough overview of the many advantages of nanoparticle vaccines, including an enhanced host immune response, multivalent antigen delivery, and efficient drug delivery. The main objective is to provide a reference for the development of innovative antiviral vaccines.