No abstract

Melanoma originates in the epidermis and becomes metastatic after invasion into the dermis. Prior interactions between melanoma cells and dermis are poorly studied. Here, we show that melanoma cells directly affect the formation of the dermal tumour niche by microRNA trafficking before invasion. Melanocytes, cells of melanoma origin, are specialized in releasing pigment vesicles, termed melanosomes. In melanoma in situ, we found melanosome markers in distal fibroblasts before melanoma invasion. The melanosomes carry microRNAs into primary fibroblasts triggering changes, including increased proliferation, migration and pro-inflammatory gene expression, all known features of cancer-associated fibroblasts (CAFs). Specifically, melanosomal microRNA-211 directly targets IGF2R and leads to MAPK signalling activation, which reciprocally encourages melanoma growth. Melanosome release inhibitor prevented CAF formation. Since the first interaction of melanoma cells with blood vessels occurs in the dermis, our data suggest an opportunity to block melanoma invasion by preventing the formation of the dermal tumour niche.

Overexpressed extracellular matrix (ECM) in pancreatic ductal adenocarcinoma (PDAC) limits drug penetration into the tumor and is associated with poor prognosis. Here, we demonstrate that a pretreatment based on a proteolytic-enzyme nanoparticle system disassembles the dense PDAC collagen stroma and increases drug penetration into the pancreatic tumor. More specifically, the collagozome, a 100 nm liposome encapsulating collagenase, was rationally designed to protect the collagenase from premature deactivation and prolonged its release rate at the target site. Collagen is the main component of the PDAC stroma, reaching 12.8 ± 2.3% vol in diseased mice pancreases, compared to 1.4 ± 0.4% in healthy mice. Upon intravenous injection of the collagozome, ∼1% of the injected dose reached the pancreas over 8 h, reducing the level of fibrotic tissue to 5.6 ± 0.8%. The collagozome pretreatment allowed increased drug penetration into the pancreas and improved PDAC treatment. PDAC tumors, pretreated with the collagozome followed by paclitaxel micelles, were 87% smaller than tumors pretreated with empty liposomes followed by paclitaxel micelles. Interestingly, degrading the ECM did not increase the number of circulating tumor cells or metastasis. This strategy holds promise for degrading the extracellular stroma in other diseases as well, such as liver fibrosis, enhancing tissue permeability before drug administration.

Protocells, artificial cell-like particles, capable of autonomously synthesizing RNA and proteins based on a DNA template, are emerging platforms for studying cellular functions and for revealing the origins-of-life. Here, we show for the first time that artificial lipid-based vesicles, containing the molecular machinery necessary for transcription and translation, can be used to synthesize anti-cancer proteins inside tumors. The particles were engineered as stand-alone systems, sourcing nutrients from their biological microenvironment to trigger protein synthesis. When pre-loaded with template DNA, amino acids and energy-supplying molecules protocells synthesized, up to 2×107 copies of superfolder green fluorescent protein (sfGFP) were synthesized in each liposome. A variety of proteins, having molecular weights reaching 66 kDa and with diagnostic and therapeutic activities, were synthesized inside the particles. Incubating protein producing particles, encoded to secrete Pseudomonas exotoxin A (PE) with 4T1 breast cancer cells in culture, resulted in killing of most of the malignant cells. In mice bearing 4T1 tumors, histological evaluation of the tumor tissue after a local injection of PE-producing particles, indicating robust apoptosis. Protein producing particles are synthetic-biology platforms capable of synthesizing therapeutic proteins on-demand.

Personalized medicine promises to revolutionize cancer therapy by matching the most effective treatment to the individual patient. Using a nanoparticle-based system, we predict the therapeutic potency of anticancer medicines in a personalized manner. We carry out the diagnostic stage through a multidrug screen performed inside the tumour, extracting drug activity information with single cell sensitivity. By using 100 nm liposomes, loaded with various cancer drugs and corresponding synthetic DNA barcodes, we find a correlation between the cell viability and the drug it was exposed to, according to the matching barcodes. Based on this screen, we devise a treatment protocol for mice bearing triple-negative breast-cancer tumours, and its results confirm the diagnostic prediction. We show that the use of nanotechnology in cancer care is effective for generating personalized treatment protocols.

As the world population grows, there is a need for efficient agricultural technologies to provide global food requirements and reduce environmental toll. In medicine, nanoscale drug delivery systems grant improved therapeutic precision by overcoming biological barriers and enhancing drug targeting to diseased tissues. Here, we loaded nanoscale drug-delivery systems with agricultural nutrients, and applied them to the leaves of tomato plants. We show that the nanoparticles – liposomes composed of plant-derived lipids, penetrate the leaf and translocate in a bidirectional manner, distributing to other leaves and to the roots. The liposomes were then internalized by the plant cells, where they released their active ingredient. Up to 33% of the applied nanoparticles penetrated the leaf, compared to less than one percent of free-molecules applied in a similar manner. In our study, tomato plants treated with liposomes loaded with Fe and Mg overcame acute nutrient deficiency which was not treatable using ordinary agricultural nutrients. Furthermore, to address regulatory concerns regarding airborne nanoparticles, we rationally designed liposomes that were stable only over short spraying distances (less than 2 meters), while the liposomes disintegrated into safe molecular building blocks (phospholipids) over longer airborne distances. These findings support expanding the implementation of nanotechnology for delivering micronutrients to agricultural crops for increasing yield.

Rationale: Through localized delivery of rapamycin via a biomimetic drug delivery system, it is possible to reduce vascular inflammation and thus the progression of vascular disease. Objective: Use biomimetic nanoparticles to deliver rapamycin to the vessel wall to reduce inflammation in an in vivo model of atherosclerosis after a short dosing schedule. Methods and Results: Biomimetic nanoparticles (leukosomes) were synthesized using membrane proteins purified from activated J774 macrophages. Rapamycin-loaded nanoparticles were characterized using dynamic light scattering and were found to have a diameter of 108±2.3 nm, a surface charge of −15.4±14.4 mV, and a polydispersity index of 0.11 +/ 0.2. For in vivo studies, ApoE −/− mice were fed a high-fat diet for 12 weeks. Mice were injected with either PBS, free rapamycin (5 mg/kg), or rapamycin-loaded leukosomes (Leuko-Rapa; 5 mg/kg) once daily for 7 days. In mice treated with Leuko-Rapa, flow cytometry of disaggregated aortic tissue revealed fewer proliferating macrophages in the aorta (15.6±9.79 %) compared with untreated mice (30.2±13.34 %) and rapamycin alone (26.8±9.87 %). Decreased macrophage proliferation correlated with decreased levels of MCP (monocyte chemoattractant protein)-1 and IL (interleukin)-b1 in mice treated with Leuko-Rapa. Furthermore, Leuko-Rapa–treated mice also displayed significantly decreased MMP (matrix metalloproteinases) activity in the aorta (mean difference 2554±363.9, P =9.95122×10 −6 ). No significant changes in metabolic or inflammation markers observed in liver metabolic assays. Histological analysis showed improvements in lung morphology, with no alterations in heart, spleen, lung, or liver in Leuko-Rapa–treated mice. Conclusions: We showed that our biomimetic nanoparticles showed a decrease in proliferating macrophage population that was accompanied by the reduction of key proinflammatory cytokines and changes in plaque morphology. This proof-of-concept showed that our platform was capable of suppressing macrophage proliferation within the aorta after a short dosing schedule (7 days) and with a favorable toxicity profile. This treatment could be a promising intervention for the acute stabilization of late-stage plaques.

Biomimetic nanovesicles deriving from leukocytes membrane proteins, called leukosomes, exhibit increased targeting of cancer vasculature and stroma by exploiting the inflammatory pathway responsible for recruiting immune cells to the cancer lesion.