Messenger ribonucleic acid (mRNA)-based therapeutics hold great prospects in disease treatment and lipid nanoparticles (LNPs) are the most extensively applied non-viral platform for RNA delivery in clinics. Despite the clinical success of LNPs as vehicles have been achieved, developing LNPs with enhanced mRNA transmembrane delivery and transfection efficiency in a non-toxic manner is highly desirable and challenging. In this study, we designed a series of new ionizable amino lipids with piperazine-derived headgroups and constructed a group of LNPs to promote the transfection activity of mRNA cargos. Among them, LNP formulated with lipid 10 (L10-LNP) can efficiently package mRNA and perform superior transfection efficiency both in vitro and in vivo, which is mainly attributed to the improved intracellular uptake and effective endosomal escape. We verified that a single administration of L10-LNP packaging interleukin (IL)-12 mRNA induced tumor shrink and even regression by robust activation of immune effector CD8⁺ T cells and stimulating the generation of IFN-γ without causing systemic toxicity, which provides a promising platform for clinical cancer immunotherapy.

Proteins have been widely used in the biomedical field because of their well-defined architecture, accurate molecular weight, excellent biocompatibility and biodegradability, and easy-to-functionalization. Inspired by the wisdom of nature, increasing proteins/peptides that possess self-assembling capabilities have been explored and designed to generate nanoassemblies with unique structure and function, including spatially organized conformation, passive and active targeting, stimuli-responsiveness, and high stability. These characteristics make protein/peptide-based nanoassembly an ideal platform for drug delivery and vaccine development. In this review, we focus on recent advances in subsistent protein/peptide-based nanoassemblies, including protein nanocages, virus-like particles, self-assemblable natural proteins, and self-assemblable artificial peptides. The origin and characteristics of various protein/peptide-based assemblies and their applications in drug delivery and vaccine development are summarized. In the end, the prospects and challenges are discussed for the further development of protein/peptide-based nanoassemblies.