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Biomimetic nanoparticles aim to effectively emulate the behavior of either cells or exosomes. Leukocyte-based biomimetic nanoparticles, for instance, incorporate cell membrane proteins to transfer the natural tropism of leukocytes to the final delivery platform. However, tuning the protein integration can affect the in vivo behavior of these nanoparticles and alter their efficacy. Here we show that, while increasing the protein:lipid ratio to a maximum of 1:20 (w/w) maintained the nanoparticle’s structural properties, increasing protein content resulted in improved targeting of inflamed endothelium in two different animal models. Our combined use of a microfluidic, bottom-up approach and tuning of a key synthesis parameter enabled the synthesis of reproducible, enhanced biomimetic nanoparticles that have the potential to improve the treatment of inflammatory-based conditions through targeted nanodelivery.

Ponatinib (Pon) is a multi-tyrosine kinase inhibitor that demonstrated high efficiency for treating cancer. However, severe side effects caused by Pon off-targeting effects prevent its extensive use. Using our understanding into the mechanisms by which Pon is transported by bovine serum albumin in the blood, we have successfully encapsulated Pon into a biomimetic nanoparticle (NP). This lipid NP (i.e., "leukosomes") incorporates membrane proteins purified from activated leukocytes that enable immune evasion, and enhanced targeting of inflamed endothelium NPs have been characterized for their size, charge, and encapsulation efficiency. Membrane proteins enriched on the NP surface enabled modulation of Pon release. These NP formulations showed promising dose-response results on two different murine osteosarcoma cell lines, F420 and RF379. Our results indicate that our fabrication method is reproducible, nonuser-dependent, efficient in loading Pon, and applicable toward repurposing numerous therapeutic agents previously shelved due to toxicity profiles.

The solid tumour microenvironment includes nerve fibres that arise from the peripheral nervous system(1,2). Recent work indicates that newly formed adrenergic nerve fibres promote tumour growth, but the origin of these nerves and the mechanism of their inception are unknown(1,3). Here, by comparing the transcriptomes of cancer-associated trigeminal sensory neurons with those of endogenous neurons in mouse models of oral cancer, we identified an adrenergic differentiation signature. We show that loss of TP53 leads to adrenergic transdifferentiation of tumour-associated sensory nerves through loss of the microRNA miR-34a. Tumour growth was inhibited by sensory denervation or pharmacological blockade of adrenergic receptors, but not by chemical sympathectomy of pre-existing adrenergic nerves. A retrospective analysis of samples from oral cancer revealed that p53 status was associated with nerve density, which was in turn associated with poor clinical outcomes. This crosstalk between cancer cells and neurons represents mechanism by which tumour-associated neurons are reprogrammed towards an adrenergic phenotype that can stimulate tumour progression, and is a potential target for anticancer therapy.

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.

In the last decades, several approaches were developed to design drug delivery systems to address the multiple biological barriers encountered after administration while safely delivering a payload. In this scenario, bio-inspired and bio-mimetic approaches have emerged as promising solutions to evade the mononuclear phagocytic system while simultaneously negotiating the sequential transport across the various biological barriers. Leukocytes freely circulate in the bloodstream and selectively target the inflamed vasculature in response to injury, infection, and cancer. Recently we have shown the use of biomimetic nanovesicles, called leukosomes, which combine both the physical and biological properties of liposomes and leukocytes, respectively, to selectively deliver drugs to the inflamed vasculature. Here we report the use of leukosomes to target and deliver doxorubicin, a model chemotherapeutic, to tumors in syngeneic murine models of breast cancer and melanoma. Exploiting the inflammatory pathway responsible for recruiting immune cells to the site of injury, leukosomes exhibited increased targeting of cancer vasculature and stroma. Furthermore, delivery of doxorubicin with leukosomes enabled significant tumor growth inhibition compared with free doxorubicin in both breast and melanoma tumors. This study demonstrates the promise of using biomimetic nanovesicles for effective cancer management in solid tumors.

Throughout the female menstrual cycle, physiological changes occur that affect the biodistribution of nanoparticles within the reproductive system. We demonstrate a 2-fold increase in nanoparticle accumulation in murine ovaries and uterus during ovulation, compared to the non-ovulatory stage, following intravenous administration. This biodistribution pattern had positive or negative effects when drug loaded nanoparticles, sized 100-nm or smaller, were used to treat different cancers. For example, treating ovarian cancer with nanomedicines during mouse ovulation resulted in higher drug accumulation in the ovaries, improving therapeutic efficacy. Conversely, treating breast cancer during ovulation, led to reduced therapeutic efficacy, due to enhanced nanoparticle accumulation in the reproductive system rather than at the tumor site. Moreover, chemotherapeutic nanoparticles administered during ovulation increased ovarian toxicity and decreased fertility compared to the free drug. The menstrual cycle should be accounted for when designing and implementing nanomedicines for females.

Humanized Biomimetic Nanovesicles In article number 2101437, Assaf Zinger, Francesca Taraballi, Robert Krencik, and co‐workers optimize and validate the scalable production of neuron‐targeting biomimetic nanovesicles (NV) with distinct lipid backbones suited to potential therapeutic cargo by integrating membrane proteins from human pluripotent stem cell‐derived neurons. NVs with neuronderived membrane proteins exhibit enhanced neuronal association and uptake compared to bare NVs. These customizable NVs enable next‐generation functionalized theranostics for neurodegeneration. [Image: see text]

Pancreatic cancers, both adenocarcinomas and endocrine tumors are characterized by varying levels of aberrant angiogenesis and fibrotic microenvironment. The difficulty to deliver drugs and treat the disease has been attributed in part to the vascular architecture and tissue/ECM density. Here we present longitudinal three-dimensional intravital imaging of vascular and tumor microenvironment remodeling in spontaneous transgenic tumors (RIP1-Tag2 insulinomas) and orthotopically injected tumors (KPC adenocarcinomas). Analysis of the data acquired in insulinomas revealed major differences in tumor blood vessel branching, fraction volume, number of branch points segments, vessel straightness and length compared to the normal tissue. The aggressive adenocarcinoma presented widespread peritumoral vascular remodeling and heterogeneous vascular distribution. Longitudinal imaging was used to acquire sequential vascular remodeling data during tumor progression. This work demonstrates the potential for using a pancreatic intravital imaging window for direct visualization of the tumor heterogenic microenvironments during tumor progression.

Despite numerous advances in medical treatment, sepsis remains one of the leading causes of death worldwide. Sepsis is characterized by the involvement of all organs and tissues as a consequence of blood poisoning, resulting in organ failure and eventually death. Effective treatment remains an unmet need and novel approaches are urgently needed. The growing evidence of clinical and biological heterogeneity of sepsis suggests precision medicine as a possible key for achieving therapeutic breakthroughs. In this scenario, biomimetic nanomedicine represents a promising avenue for the treatment of inflammatory diseases, including sepsis. We investigated the role of macrophage-derived biomimetic nanoparticles, namely leukosomes, in a lipopolysaccharide-induced murine model of sepsis. We observed that treatment with leukosomes was associated with significantly prolonged survival. In vitro studies elucidated the potential mechanism of action of these biomimetic vesicles. The direct treatment of endothelial cells (ECs) with leukosomes did not alter the gene expression profile of EC-associated cell adhesion molecules. In contrast, the interaction of leukosomes with macrophages induced a decrease of pro-inflammatory genes (IL-6, IL-1b, and TNF-α), an increase of anti-inflammatory ones (IL-10 and TGF-β), and indirectly an anti-inflammatory response on ECs. Taken together, these results showed the ability of leukosomes to regulate the inflammatory response in target cells, acting as a bioactive nanotherapeutic.

Efficient communication is essential in all layers of the biological chain. Cells exchange information using a variety of signaling moieties, such as small molecules, proteins, and nucleic acids. Cells carefully package these messages into lipid complexes, collectively named extracellular vesicles (EVs). In this work, we discuss the nature of these cell carriers, categorize them by their origin, explore their role in the homeostasis of healthy tissues, and examine how they regulate the pathophysiology of several diseases. This review will also address the limitations of using EVs for clinical applications and discuss novel methods to engineer nanoparticles to mimic the structure, function, and features of EVs. Using lessons learned from nature and understanding how cells use EVs to communicate across distant sites, we can develop a better understanding of how to tailor the fundamental features of drug delivery carriers to encapsulate various cargos and target specific sites for biomedicine and bioengineering.

Throughout the female menstrual cycle, physiological changes occur that affect the biodistribution of nanoparticles within the reproductive system. This can have positive or negative effects. We demonstrate a 2-fold increase in nanoparticle accumulation in the ovaries during female mouse ovulation compared to the non-ovulatory stage following intravenous administration. Accumulation in the reproductive system is favored by nanoparticles smaller than 100 nm. Chemotherapeutic nanoparticles administered during ovulation increased ovarian toxicity and decreased short-term and long-term fertility when compared to the free drug. Breast cancer treated with nanomedicines during ovulation results in higher drug accumulation in the reproductive system rather than at the site of the tumor, reducing treatment efficacy. Conversely, ovarian cancer treatment was improved by enhanced nanoparticle accumulation in the ovaries during ovulation. Our findings suggest that the menstrual cycle should be considered when designing and implementing nanotherapeutics for females.

Nanovesicles (NVs) are emerging as innovative, theranostic tools for cargo delivery. Recently, surface engineering of NVs with membrane proteins from specific cell types has been shown to improve the biocompatibility of NVs and enable the integration of functional attributes. However, this type of biomimetic approach has not yet been explored using human neural cells for applications within the nervous system. Here, this paper optimizes and validates the scalable and reproducible production of two types of neuron‐targeting NVs, each with a distinct lipid formulation backbone suited to potential therapeutic cargo, by integrating membrane proteins that are unbiasedly sourced from human pluripotent stem‐cell‐derived neurons. The results establish that both endogenous and genetically engineered cell‐derived proteins effectively transfer to NVs without disruption of their physicochemical properties. NVs with neuron‐derived membrane proteins exhibit enhanced neuronal association and uptake compared to bare NVs. Viability of 3D neural sphere cultures is not disrupted by treatment, which verifies the utility of organoid‐based approaches as NV testing platforms. Finally, these results confirm cellular association and uptake of the biomimetic humanized NVs to neurons within rodent cranial nerves. In summary, the customizable NVs reported here enable next‐generation functionalized theranostics aimed to promote neuroregeneration., Membrane proteins are extracted from either human pluripotent stem cells or differentiated neurons and combined with lipids to synthesize biomimetic nanovesicles (NVs). Neural targeting of NVs can be evaluated both in vitro using monolayer cultures and 3D organoids and in vivo by direct injection of NVs into murine trigeminal ganglions.

Osteosarcoma (OS) is the most common pediatric bone tumor with a worldwide incidence of 3.4 cases per million people annually. Unfortunately, current treatments are still not sufficient to eradicate OS, due to its ability to resist the upfront standard chemotherapy. Therefore, it is essential to identify and effectively deliver novel therapeutic regimens. Multi-tyrosine kinase inhibitors have been explored as new therapeutics for different sarcomas. Among many, Ponatinib (Pon) demonstrated very potent anti-tumor activity, however, it received a black box warning from the FDA due to significant cardiovascular side effects. Recently, our lab developed novel biomimetic nanoparticles (NPs) called Leukosomes (Leuko) capable of encapsulating and effectively releasing Pon. These NPs are synthesized from activated leukocytes, maintaining leukocytes' tropism towards inflamed endothelium. Leveraging on this technology, we aim to validate the therapeutic potential of Leuko in 3D OS tumor model (sarcospheres) and their ability to target primary murine OS model while concomitantly reducing the detrimental side effects. Given its biological relevance and ability to better recapitulate the tumor structure, a 3D tumor model was chosen to reproduce key properties, such as diffusion limitations and the cellular network of solid tumors that have significant impacts on cancer drug efficacy.In the sarcospheres model, we observed efficient penetration and internalization of NPs in both, murine (RF379, 577) and human PDX derived (PDX94, pPDX202) OS cell lines, where Leuko exhibited a 20% increase in targeting vs the control Liposome (Lipo). This difference was not detected in the control 2D model. Moreover, our data demonstrated a 2-fold increase in the Leuko cytotoxic effect in 3D compared to 2D systems. Murine OS cell viability was 20% lower in sarcospheres after treatment with the IC50 for Pon. In addition, NPs induced complete inhibition of murine sarcosphere formation in the extreme limiting dilution assay (ELDA). These findings were also confirmed using the PDX derived OS cell lines. Subsequently, an in vivo intratibial syngeneic orthotopic mouse model was utilized to determine the targeting and biodistribution of the NPs. Leuko showed an increased targeting and penetration in the tumor 1 and 3h post NPs injection as anticipated by the 3D in vitro studies. By exploiting the inflammatory conditions within the tumor, which increases the Leuko accumulation, these preliminary results advocate the translational potential of this innovative formulation as a new targeted drug delivery approach for OS. This promising platform could improve the clinical therapeutic approaches and lead to improved outcomes and reduced side effects for OS patients. Citation Format: Federica Giordano, Stefania Lenna, Riccardo Rampado, April Ewing, Gherardo Baudo, Matteo Massaro, Assaf Zinger, Enrica De Rosa, Jason T Yustein, Francesca Taraballi. Ponatinib loaded leukocyte-based nanoparticles for osteosarcoma treatment in sarcosphere tumor model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 311.

The solid tumor microenvironment includes nerve fibers that arise from the peripheral nervous system. Recent work indicates that newly formed adrenergic nerve fibers promote tumor growth, but the origin of these nerves and the mechanism of their inception are unknown. Here, by comparing the transcriptomes of cancer-associated trigeminal sensory neurons with those of endogenous neurons in multiple mouse models of oral cancer, we identified an adrenergic differentiation signature. We show that loss of TP53 leads to adrenergic transdifferentiation of tumor-associated sensory nerves through loss of the microRNA miR-34a. Tumor cells that expressed wild-type p53 protein released vesicles containing microRNAs that were taken up by neighboring neurons. MiR-34a blocks neuronal proliferation, and the neurons were maintained in their current state. By contrast, tumors that had a mutant versions of the gene encoding p53 released vesicles that lacked miR-34a. In this case, neurons increased in number in the vicinity of the tumor, and these cells were reprogrammed as adrenergic neurons that express the molecule noradrenaline. These neurons had more axonal branches than did those near tumors that expressed wild-type p53. Interactions between adrenergic neurons and the tumor aided cancer growth. Tumor growth was inhibited by sensory denervation or pharmacological blockade of adrenergic receptors, but not by chemical sympathectomy of pre-existing adrenergic nerves; and when mice received a transplant of p53-deficient tumor cells, treatment with a drug (carvedilol) that blocks adrenergic signaling pathways slowed tumor growth. A retrospective analysis of tumor samples from patients with oral cancer revealed that p53 status was associated with nerve density, which was in turn associated with poor clinical outcomes. Neural regulation represents an emerging targetable pathway for the treatment of cancer. The peripheral adrenergic nervous system has previously been shown to regulate cancer tumorigenesis. In contrast to previous findings using a prostate cancer mouse model, in our oral cancer mouse model, ablation of the sympathetic nervous system before tumor inoculation neither abrogated the development of adrenergic neo-nerves nor inhibited tumor growth. Our present study reveals that the emergence of adrenergic neonerves in the tumor microenvironment accompanies the initial phase of oral cavity squamous cell carcinoma (OCSCC) development in a transgenic OCSCC mouse models. We have identified crosstalk between the peripheral nervous system and head and neck tumors and described a phenotypic switch, induced by cancer cells, in which sensory nerves differentiate into adrenergic neo-neurons. This crosstalk between cancer cells and neurons represents mechanism by which tumor-associated neurons are reprogrammed towards an adrenergic phenotype that can stimulate tumor progression, and is a potential target for anticancer therapy. Our findings show that in p53-deficient tumors, an miRNA-based mechanism mediates neuronal responses to environmental cues and determines the fate of cancer-associated neurons. We have shown that axonal sprouting and autonomic reprogramming of existing nerves occur as a result of exosomal miRNA shuttling from cancer cells to neurons. These miRNAs orchestrate gene expression via combined dominantly negative (for example, miR-34a) and positive (for example, miR-21 and miR-324) effects, activating transcriptional programs that establish neuronal identity. In our mouse model of OCSCC, surgical ablation of sensory nerves prevented the development of these adrenergic neo-nerves; and as tumors evolve, neo-neural networks develop in and around the tumor stroma, providing signals that coordinate cancer progression. Our results thus show that the peripheral sensory nerves may be reprogrammed during the development of cancer in a manner similar to that of neural progenitors that initiate adrenergic neurogenesis during tumor formation. These results are consistent with recent preclinical data suggesting that sympathetic fibers accumulate in the normal vicinity of solid tumor tissues and infiltrate into the stroma. Furthermore, clinical data show that cancer patients treated with β-blockade have improved survival, supporting the role of adrenergic nerve activity in cancer progression. Although further studies will be required to dissect the molecular events that link tumor-associated neuritogenesis to cancer progression, our data raise the tantalizing possibility that drugs that target both axonal growth and the adrenergic nervous system could be useful for the treatment of cancer. Moreover, our discovery that the absence of functional p53 influences the formation of neighboring neurons might have relevance for interpreting reports showing that fluctuations in the levels of wild-type p53 are observed in nerve regeneration. Thus, these findings might have repercussions that reach beyond the field of cancer research to regenerative medicine. Citation Format: Moran Amit, Hideaki Takahashi, Mihnea-Paul Dragomir, Simone Anfossi, Antje Lindemann, Frederico Netto-Glebber, Samantha Tam, Abdullah Osman, Erik Kuntsen, Curtis R. Pickering, Mei Zhao, Xiayu Rao, Jing Wang, Deborah A. Silverman, Carlos Caulin, Assaf Zinger, Ennio Tasciotti, Patrick Dougherty, Adel El-Naggar, George A. Calin, Jeffrey N. Myers. Cancer takes a nerve: Loss of p53 drives neuron reprogramming in head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr NG07.

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.

Key Points • Why do we need biomimicry? Which challenges does it aim to overcome? • Systemic delivery of free drugs has limitations. These limitations include rapid systemic clearance, inadequate levels of drug in the target tissue, poor solubility of some drugs, and increased off target toxicity. • Much effort has been invested into the development of different synthetic drug carriers. However, biomimetic carrier systems, inspired by the way different cells in our body behave, hold great therapeutic potential in addressing these challenges. • Several types of cells that interact with the vascular system, including erythrocytes, leukocytes, and thrombocytes, have inspired the design of new biomimetic carriers. • Inspired by native cells' biological functions, biomimetic nano-carrier platforms possess favorable properties such as: longer circulation times, mononuclear phagocyte system (MPS) evasion, and favorable interactions with target cells.

Traumatic brain injury (TBI) triggers both central and peripheral inflammatory responses. Existing pharmacological drugs are unable to effectively and quickly target the brain inflamed regions, setting up a major roadblock towards effective brain trauma treatments. Nanoparticles (NPs) have been used in multiple diseases as drug delivery tools with remarkable success due to their rapid diffusion and specificity in the target organ. Here, leukocyte‐based biomimetic NPs are fabricated as a theranostic tool to directly access inflamed regions in a TBI mouse model. This NP systemic delivery is visualized using advanced in vivo imaging techniques, including intravital microscopy and in vivo imaging system. The results demonstrate selective targeting of NPs to the injured brain and increased NPs accumulation among the peripheral organs 24 h after TBI. Interestingly, increased microglial proliferation, decreased macrophage infiltration, and reduced brain lesion following the NPs treatments compared to sham vehicle‐treated mice are also found. In summary, the results suggest that NPs represent a promising future theranostic tool for TBI treatment., Leukosomes are fabricated using lipids mixed with membrane proteins extracted from cultivated leukocytes. Leukosomes are tested in vivo using a traumatic brain injury (TBI) mouse model and demonstrated increased targeting to inflamed organs following TBI in both sexes.

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.

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 2×10(7) 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., Determining the most effective treatment for each cancer patient is a key challenge in cancer therapy. In this article, the authors show, in a mouse model of breast cancer, that DNA barcoded nanoparticles can be used for pre-screening the efficacy of anticancer drugs.

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.

Despite advances in cancer therapy, treating cancer after it has metastasized remains an unmet clinical challenge. In this study we demonstrate that 100 nm liposomes target triple-negative murine breast-cancer metastases post intravenous administration. Metastatic breast cancer was induced in BALB/c mice either experimentally, by a tail vein injection of 4T1 cells, or spontaneously, after implanting a primary tumor xenograft. To track their biodistribution in vivo the liposomes were labeled with multi-modal diagnostic agents, including indocyanine green and rhodamine for whole-animal fluorescent imaging, gadolinium for magnetic resonance imaging (MRI), and europium for a quantitative biodistribution analysis. The accumulation of liposomes in the metastases peaked at 24 h post the intravenous administration, similar to the time they peaked in the primary tumor. The efficiency of liposomal targeting to the metastatic tissue exceeded that of a non-liposomal agent by 4.5-fold. Liposomes were detected at very early stages in the metastatic progression, including metastatic lesions smaller than 2 mm in diameter. Surprisingly, while nanoparticles target breast cancer metastasis, they may also be found in elevated levels in the pre-metastatic niche, several days before metastases are visualized by MRI or histologically in the tissue. This study highlights the promise of diagnostic and therapeutic nanoparticles for treating metastatic cancer, possibly even for preventing the onset of the metastatic dissemination by targeting the pre-metastatic niche.

Therapeutic nanotechnologies have made great progress over the past decade. Skepticism has been replaced by the understanding that precision at the nanoscale allows improved treatment modalities in humans. Principles for designing tumor-targeted drug delivery systems are described. At first, the enhanced permeability and retention (EPR) effect was the major targeting mode, with up to 10 % of the injected dose actually reaching tumors. To improve cellular uptake, sugars, antibodies, peptides or other ligands were added to the surface of nanotherapeutics. These can be coupled with external magnetic fields or ultrasonic waves to propel iron oxide or gas-filled particles towards the disease site. Next-generation drug delivery systems will be capable of autonomously swimming towards the disease site and penetrating deep tissue, independent of blood or lymphatic flow. This has been shown to some extent with modified, drug-producing, bacteria. Interestingly, sperm may be nature’s best example of a multifunctional, targeted, high-fidelity, self-propelled, delivery system that we can learn from.

Acidic pH in the tumor microenvironment is associated with cancer metabolism and creates a physiological barrier that prevents from drugs to penetrate cells. Specifically, ionizable weak-base drugs, such as doxorubicin, freely permeate membranes in their uncharged form, however, in the acidic tumor microenvironment these drugs become charged and their cellular permeability is retarded. In this study, 100-nm liposomes loaded with sodium bicarbonate were used as adjuvants to elevate the tumor pH. Combined treatment of triple-negative breast cancer cells (4T1) with doxorubicin and sodium-bicarbonate enhanced drug uptake and increased its anti-cancer activity. In vivo, mice bearing orthotropic 4T1 breast cancer tumors were administered either liposomal or free bicarbonate intravenously. 3.7 ± 0.3% of the injected liposomal dose was detected in the tumor after twenty-four hours, compared to 0.17% ± 0.04% in the group injected free non-liposomal bicarbonate, a 21-fold increase. Analyzing nanoparticle biodistribution within the tumor tissue revealed that 93% of the PEGylated liposomes accumulated in the extracellular matrix, while 7% were detected intracellularly. Mice administered bicarbonate-loaded liposomes reached an intra-tumor pH value of 7.38 ± 0.04. Treating tumors with liposomal bicarbonate combined with a sub-therapeutic dose of doxorubicin achieved an improved therapeutic outcome, compared to mice treated with doxorubicin or bicarbonate alone. Interestingly, analysis of the tumor microenvironment demonstrated an increase in immune cell’ population (T-cell, B-cell and macrophages) in tumors treated with liposomal bicarbonate. This study demonstrates that targeting metabolic adjuvants with nanoparticles to the tumor microenvironment can enhance anticancer drug activity and improve treatment.