Preparation and Application of Cell Membrane-Camouflaged Nanoparticles for Cancer Therapy

Recent Advances of Membrane-Cloaked Nanoplatforms for Biomedical Applications

In terms of the extremely small size and large specific surface area, nanomaterials often exhibit unusual physical and chemical properties, which have recently attracted considerable attention in bionanotechnology and nanomedicine. Currently, the extensive usage of nanotechnology in medicine holds great potential for precise diagnosis and effective therapeutics of various human diseases in clinical practice. However, a detailed understanding regarding how nanomedicine interacts with the intricate environment in complex living systems remains a pressing and challenging goal. Inspired by the diversified membrane structures and functions of natural prototypes, research activities on biomimetic and bioinspired membranes, especially for those cloaking nanosized platforms, have increased exponentially. By taking advantage of the flexible synthesis and multiple functionality of nanomaterials, a variety of unique nanostructures including inorganic nanocrystals and organic polymers have been widely devised to substantially integrate with intrinsic biomoieties such as lipids, glycans, and even cell and bacteria membrane components, which endow these abiotic nanomaterials with specific biological functionalities for the purpose of detailed investigation of the complicated interactions and activities of nanomedicine in living bodies, including their immune response activation, phagocytosis escape, and subsequent clearance from vascular system. In this review, we summarize the strategies established recently for the development of biomimetic membrane-cloaked nanoplatforms derived from inherent host cells (e.g., erythrocytes, leukocytes, platelets, and exosomes) and invasive pathogens (e.g., bacteria and viruses), mainly attributed to their versatile membrane properties in biological fluids. Meanwhile, the promising biomedical applications based on nanoplatforms inspired by diverse moieties, such as selective drug delivery in targeted sites and effective vaccine development for disease prevention, have also been outlined. Finally, the potential challenges and future prospects of the biomimetic membrane-cloaked nanoplatforms are also discussed.

Necroptotic cancer cells-mimicry nanovaccine boosts anti-tumor immunity with tailored immune-stimulatory modality

Recent breakthroughs in cancer immunotherapy offer new paradigm-shifting therapeutic options for combating cancer. Personalized therapeutic anti-cancer vaccines training T cells to directly fight against tumor cells endogenously offer tremendous benefits in working synergistically with immune checkpoint inhibitors. Biomimetic nanotechnology offers a versatile platform to boost anticancer immunity by efficiently co-delivering optimized immunogenic antigen materials and adjuvants to antigen presenting cells (APC). Necroptotic tumor cells can release danger associated molecule patterns (DAMPs) like heat shock proteins, being more immunogenic than naïve tumor cells. Here, nano-size "artificial necroptotic cancer cell" (αHSP70p-CM-CaP) composing of phospholipid bilayer and a phosphate calcium core was designed as a flexible vaccine platform for co-delivering cancer membrane proteins (CM), DAMPs signal-augmenting element α-helix HSP70 functional peptide (αHSP70p) and CpG to both natural killer (NK) cells and APC. Mechanically, immunogenic B16OVA tumor cells membrane-associated antigens and αHSP70p were reconstituted in artificial outer phospholipid bilayer membrane via one-step hydration and CpG encapsulated in the phosphate calcium core. The resulted αHSP70p-CM-CaP exhibited 30 nm in diameter with the immunogenic membrane proteins reserved in the particles to produce synergistic effect on bone marrow derived dendritic cells maturation and antigen-presentation. Following αHSP70p-CM-CaP vaccination, efficient lymph node trafficking and multi-epitope-T cells response was observed in mice. Vitally, αHSP70p-CM-CaP was also able to induce expansion of IFN-γ-expressing CD8⁺ T cells and NKG2D⁺ NK cells subsets. Most promisingly, αHSP70p-CM-CaP vaccination led to the killing of target cells and tumor regression in vivo when combined with anti-PD-1 antibody treatment on mice B16OVA melanoma models. Altogether, we demonstrated proof-of-concept evidence for the feasibility, capability and safety of a nanovaccine platform towards efficient personalized anticancer application.

Cell membrane-coated nanocarriers: the emerging targeted delivery system for cancer theranostics

Cancer is a leading cause of death worldwide. The use of nanocarriers (NCs) has generated significant interest to improve cancer therapy by targeted delivery. However, conventional NCs in general lack specificity and have poor biodistribution, resulting in low efficacy in cancer therapy. To circumvent this problem, there has been an increasing focus on cancer cell membrane-coated NCs (CCMCNCs), which can deliver therapeutics directly to tumor cells. CCMCNCs comprise active cancer cell surface adhesive molecules combined with other functional proteins, and offer extended blood circulation with robust cell-specific targeting, ensuring enhanced intratumoral penetration and higher tumor-specific accumulation of NCs. In this review, we discuss the preparation, homologous targeting mechanisms, and application of CCMCNCs in targeted cancer therapy.

Tools for Pathogen Proteomics: Fishing with Biomimetic Nanosponges

The identification of the major virulence factors that drive pathogenicity is critical for gaining insight into the underlying molecular mechanisms of diseases. Although genetic approaches combined with functional analyses have markedly increased the rate of virulence factor discovery, the divergence between genome and proteome can impair the identification of important markers, in particular, of those that act in concert or depend on specific environmental factors. Recently, membrane-coated nanomaterials mimicking source cells of interest have emerged as powerful tools that can be used for improved tumor targeting and as "nanotraps" to capture chemokines and bacterial toxins. In this issue of ACS Nano, Lapek et al. demonstrate that membrane-coated nanosponges in combination with quantitative proteomics can also be used as efficient "fishing devices" for the identification of cell-type-specific virulence factors.