Conjugation-Free Multilamellar Protein-Lipid Hybrid Vesicles for Multifaceted Immune Responses

Multilayered collagen-lipid hybrid nanovesicles for retinol stabilization and efficient skin delivery

Lipid-based nanocarriers have been extensively utilized for the solubilization and cutaneous delivery of water-insoluble active ingredients in skincare formulations. However, their practical application is often limited by structural instability, leading to premature release and degradation of actives. Here we present highly robust multilamellar nanovesicles, prepared by the polyionic self-assembly of unilamellar vesicles with hydrolyzed collagen peptides, to stabilize all-trans-retinol and enhance its cutaneous delivery. Our results reveal that the reinforced multilayer structure substantially enhances dispersion stability under extremely harsh conditions, like freeze-thaw cycles, and stabilizes the encapsulated retinol. Interestingly, these multilamellar vesicles exhibit significantly lower cytotoxicity to human dermal fibroblasts than their unilamellar counterparts, likely due to their smaller particle number per weight, minimizing potential disruptions to cellular membranes. In artificial skin models, retinol-loaded multilamellar vesicles effectively upregulate collagen-related gene expression while suppressing the synthesis of metalloproteinases. These findings suggest that the robust multilamellar vesicles can serve as effective nanocarriers for the efficient delivery and stabilization of bioactive compounds in cutaneous applications.

Biomimetic Multilayered Lipid Nanovesicles for Potent Protein Vaccination

Lipid vesicles are widely used for drug and gene delivery, but their structural instability reduces in vivo efficacy and requires specialized handling. To address these limitations, strategies like lipid cross-linking and polymer-lipid conjugation are suggested to enhance stability and biological efficacy. However, the in vivo metabolism of these altered lipids remains unclear, necessitating further studies. A new stabilization technique without chemical modification is urgently needed. Here, a bio-mimetic approach for fabricating robust multilamellar lipid vesicles to enhance in vivo delivery and stabilization of protein antigens is presented. This method leverages 1-O-acylceramide, a natural skin lipid, to facilitate the self-assembly of lipid nanovesicles. Incorporating 1-O-acylceramide, anchoring lipid bilayers akin to its role in the stratum corneum, provides excellent stability under environmental stresses, including freeze-thaw cycles. Encapsulating ovalbumin as a model antigen and the adjuvant monophosphoryl lipid A demonstrates the vesicle's potential as a nanovaccine platform. In vitro studies show enhanced immune responses with both unilamellar and multilamellar vesicles, but in vivo analyses highlight the superior efficiency of multilamellar vesicles in inducing higher antibody and cytokine levels. This work suggests ceramide-induced multilamellar lipid vesicles as an effective nanovaccine platform for enhanced antigen delivery and stability.

Metal-Free Atom Transfer Radical Polymerization to Prepare Recylable Micro-Adjuvants for Dendritic Cell Vaccine

In the development of dendritic cell (DC) vaccines, the maturation of DCs is a critical stage. Adjuvants play a pivotal role in the maturation of DCs, with a major concern being to ensure both efficacy and safety. This study introduces an innovative approach that combines high efficacy with safety through the synthesis of micro-adjuvants grafted with copolymers of 2-(methacrylamido) glucopyranose (MAG) and methacryloxyethyl trimethyl ammonium chloride (DMC). The utilization of metal-free surface-initiated atom transfer radical polymerization enables the production of safe and recyclable adjuvants. These micrometer-sized adjuvants surpass the optimal size range for cellular endocytosis, enabling the retrieval and reuse of them during the ex vivo maturation process, mitigating potential toxicity concerns associated with the endocytosis of non-metabolized nanoparticles. Additionally, the adjuvants exhibit a "micro-ligand-mediated maturation enhancement" effect for DC maturation. This effect is influenced by the shape of the particle, as evidenced by the distinct promotion effects of rod-like and spherical micro-adjuvants with comparable sizes. Furthermore, the porous structure of the adjuvants enables them to function as cargo-carrying "micro-shuttles", releasing antigens upon binding to DCs to facilitate efficient antigen delivery.

Glycopolymers With On/Off Anchors: Confinement Effect on Regulating Dendritic Cells

Insufficient activation or over-activation of T cells due to the dendritic cells (DCs) state can cause negative effects on immunotherapy, making it crucial for DCs to maintain different states in different treatments. Polysaccharides are one of the most studied substances to promote DCs maturation. However, in many methods, optimizing the spatial dimension of the interaction between polysaccharides and cells is often overlooked. Therefore, in this study, a new strategy from the perspective of spatial dimension is proposed to regulate the efficacy of polysaccharides in promoting DCs maturation. An anchoring molecule (DMA) is introduced to existing glycopolymers for the confinement effect, and the effect can be turned off by oxidation of DMA. Among the prepared on-confined (PMD2 ), off-confined (PMD2 -O), and norm (PM2 ) glycopolymers, PMD2 and PMD2 -O show the best and worst results, respectively, in terms of the amount of binding to DCs and the effect on promoting DCs maturation. This sufficiently shows that the turn-on and off of confinement effect can regulate the maturation of DCs by polysaccharides. Based on the all-atom molecular dynamics (MD) simulation, the mechanism of difference in the confinement effect is explained. This simple method can also be used to regulate other molecule-cell interactions to guide cell behavior.

Self-assembling nanocarriers from engineered proteins: Design, functionalization, and application for drug delivery

Self-assembling proteins are valuable building blocks for constructing drug nanocarriers due to their self-assembly behavior, monodispersity, biocompatibility, and biodegradability. Genetic and chemical modifications allow for modular design of protein nanocarriers with effective drug encapsulation, targetability, stimuli responsiveness, and in vivo half-life. Protein nanocarriers have been developed to deliver various therapeutic molecules including small molecules, proteins, and nucleic acids with proven in vitro and in vivo efficacy. This article reviews recent advances in protein nanocarriers that are not derived from natural protein nanostructures, such as protein cages or virus like particles. The protein nanocarriers described here are self-assembled from rationally or de novo designed recombinant proteins, as well as recombinant proteins complexed with other biomolecules, presenting properties that are unique from those of natural protein carriers. Design, functionalization, and therapeutic application of protein nanocarriers will be discussed.