Publications

2018
Vinu Krishnan, Apoorva Sarode, Rohit Bhatt, Joshua De Oliveira, Tyler D. Brown, Y. P. Jiang, Jagath Reddy Junutula, and Samir Mitragotri. 6/2018. “Surface-functionalized Carrier-free Drug Nanorods for Leukemia.” Advanced Therapeutics, 1, 2. Publisher's VersionAbstract
Pure drug nanoparticles have emerged as an alternate method for formulating extremely hydrophobic drugs. Herein, a simple and efficient process for synthesizing PEGylated and antibody‐conjugated, carrier‐free nanomedicine is reported as a promising strategy to deliver the drug, Camptothecin (CPT) for aggressive circulating tumors such as Acute Myeloid Leukemia (AML). Size, shape, and surface morphology of pure drug nanorods (NRs) are examined and characterized by a variety of techniques. Incorporation of polyethylene glycol (PEG) onto the particle changed its surface charge and topography while affecting its drug‐dissolution kinetics. Furthermore, the toxicity of PEGylated versus non‐PEGylated forms of humanized anti‐CD33 antibody (Hu195Ab)–coated CPT NRs are compared. Hu195Ab drug‐linked NRs increased cell killing in leukemic cells and surface PEGylation show reduced non‐specific uptake in cells. The results demonstrate that surface‐modified carrier‐free nanodrugs could have significant implications in cancer drug delivery for treating AML. This would be the first instance of studying the potential of surface‐functionalized carrier‐free drug NRs in the treatment of leukemia.
Maria Jarvis, Michael Arnold, Jenna Ott, Vinu Krishnan, Kapil Pant, Balabhaskar Prabhakarpandian, and Samir Mitragotri. 5/2018. “Detachment of ligands from nanoparticle surface under flow and endothelial cell contact: Assessment using microfluidic devices.” Bioeng Transl Med. , 3, 2, Pp. 148-155. Publisher's VersionAbstract
Surface modification of nanoparticles is a well‐established methodology to alter their properties to enhance circulation half‐life. While literature studies using conventional, in vitro characterization are routinely used to evaluate the biocompatibility of such modifications, relatively little attention has been paid to assess the stability of such surface modifications in physiologically relevant conditions. Here, microfluidic devices were used to study the effect of factors that adversely impact surface modifications including vascular flow and endothelial cell interactions. Camptothecin nanoparticles coated with polyethylene glycol (PEG) and/or folic acid were analyzed using linear channels and microvascular networks. Detachment of PEG was observed in cell‐free conditions and was attributed to interplay between the flow and method of PEG attachment. The flow and cells also impacted the surface charge of nanoparticles. Presence of endothelial cells further increased PEG shedding. The results demonstrate that endothelial cell contact, and vascular flow parameters modify surface ligands on nanoparticle surfaces.
Rangaramanujam M Kannan and Samir Mitragotri. 2018. “Engineering clinical translation-Introduction to Special Issue Dedicated to 2017 Bioengineering and Translational Medicine Conference.” Bioeng Transl Med, 3, 2, Pp. 73.
Michaela Cooley, Apoorva Sarode, Masoud Hoore, Dmitry A Fedosov, Samir Mitragotri, and Anirban Sen Gupta. 2018. “Influence of particle size and shape on their margination and wall-adhesion: implications in drug delivery vehicle design across nano-to-micro scale.” Nanoscale, 10, 32, Pp. 15350-15364.Abstract
Intravascular drug delivery technologies majorly utilize spherical nanoparticles as carrier vehicles. Their targets are often at the blood vessel wall or in the tissue beyond the wall, such that vehicle localization towards the wall (margination) becomes a pre-requisite for their function. To this end, some studies have indicated that under flow environment, micro-particles have a higher propensity than nano-particles to marginate to the wall. Also, non-spherical particles theoretically have a higher area of surface-adhesive interactions than spherical particles. However, detailed systematic studies that integrate various particle size and shape parameters across nano-to-micro scale to explore their wall-localization behavior in RBC-rich blood flow, have not been reported. We address this gap by carrying out computational and experimental studies utilizing particles of four distinct shapes (spherical, oblate, prolate, rod) spanning nano- to-micro scale sizes. Computational studies were performed using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) package, with Dissipative Particle Dynamics (DPD). For experimental studies, model particles were made from neutrally buoyant fluorescent polystyrene spheres, that were thermo-stretched into non-spherical shapes and all particles were surface-coated with biotin. Using microfluidic setup, the biotin-coated particles were flowed over avidin-coated surfaces in absence versus presence of RBCs, and particle adhesion and retention at the surface was assessed by inverted fluorescence microscopy. Our computational and experimental studies provide a simultaneous analysis of different particle sizes and shapes for their retention in blood flow and indicate that in presence of RBCs, micro-scale non-spherical particles undergo enhanced 'margination + adhesion' compared to nano-scale spherical particles, resulting in their higher binding. These results provide important insight regarding improved design of vascularly targeted drug delivery systems.
Christian Agatemor, Kelly N Ibsen, Eden EL Tanner, and Samir Mitragotri. 2018. “Ionic liquids for addressing unmet needs in healthcare.” Bioeng Transl Med, 3, 1, Pp. 7-25.Abstract
Advances in the field of ionic liquids have opened new applications beyond their traditional use as solvents into other fields especially healthcare. The broad chemical space, rich with structurally diverse ions, and coupled with the flexibility to form complementary ion pairs enables task-specific optimization at the molecular level to design ionic liquids for envisioned functions. Consequently, ionic liquids now are tailored as innovative solutions to address many problems in medicine. To date, ionic liquids have been designed to promote dissolution of poorly soluble drugs and disrupt physiological barriers to transport drugs to targeted sites. Also, their antimicrobial activity has been demonstrated and could be exploited to prevent and treat infectious diseases. Metal-containing ionic liquids have also been designed and offer unique features due to incorporation of metals. Here, we review application-driven investigations of ionic liquids in medicine with respect to current status and future potential.
Amrita Banerjee, Kelly Ibsen, Tyler Brown, Renwei Chen, Christian Agatemor, and Samir Mitragotri. 2018. “Ionic liquids for oral insulin delivery.” Proc Natl Acad Sci U S A, 115, 28, Pp. 7296-7301.Abstract
With the rise in diabetes mellitus cases worldwide and lack of patient adherence to glycemia management using injectable insulin, there is an urgent need for the development of efficient oral insulin formulations. However, the gastrointestinal tract presents a formidable barrier to oral delivery of biologics. Here we report the development of a highly effective oral insulin formulation using choline and geranate (CAGE) ionic liquid. CAGE significantly enhanced paracellular transport of insulin, while protecting it from enzymatic degradation and by interacting with the mucus layer resulting in its thinning. In vivo, insulin-CAGE demonstrated exceptional pharmacokinetic and pharmacodynamic outcome after jejunal administration in rats. Low insulin doses (3-10 U/kg) brought about a significant decrease in blood glucose levels, which were sustained for longer periods (up to 12 hours), unlike s.c. injected insulin. When 10 U/kg insulin-CAGE was orally delivered in enterically coated capsules using an oral gavage, a sustained decrease in blood glucose of up to 45% was observed. The formulation exhibited high biocompatibility and was stable for 2 months at room temperature and for at least 4 months under refrigeration. Taken together, the results indicate that CAGE is a promising oral delivery vehicle and should be further explored for oral delivery of insulin and other biologics that are currently marketed as injectables.
Michael A Evans, Po-Ju Huang, Yuji Iwamoto, Kelly N Ibsen, Emory M Chan, Yutaka Hitomi, Peter C Ford, and Samir Mitragotri. 2018. “Macrophage-mediated delivery of light activated nitric oxide prodrugs with spatial, temporal and concentration control.” Chem Sci, 9, 15, Pp. 3729-3741.Abstract
Nitric oxide (NO) holds great promise as a treatment for cancer hypoxia, if its concentration and localization can be precisely controlled. Here, we report a "Trojan Horse" strategy to provide the necessary spatial, temporal, and dosage control of such drug-delivery therapies at targeted tissues. Described is a unique package consisting of (1) a manganese-nitrosyl complex, which is a photoactivated NO-releasing moiety (photoNORM), plus Nd-doped upconverting nanoparticles (Nd-UCNPs) incorporated into (2) biodegradable polymer microparticles that are taken up by (3) bone-marrow derived murine macrophages. Both the photoNORM [Mn(NO)dpaq ]BPh(dpaq = 2-[,-bis(pyridin-2-yl-methyl)]-amino-'-5-nitro-quinolin-8-yl-acetamido) and the Nd-UCNPs are activated by tissue-penetrating near-infrared (NIR) light at ∼800 nm. Thus, simultaneous therapeutic NO delivery and photoluminescence (PL) imaging can be achieved with a NIR diode laser source. The loaded microparticles are non-toxic to their macrophage hosts in the absence of light. The microparticle-carrying macrophages deeply penetrate into NIH-3T3/4T1 tumor spheroid models, and when the infiltrated spheroids are irradiated with NIR light, NO is released in quantifiable amounts while emission from the Nd-UCNPs provides images of microparticle location. Furthermore, varying the intensity of the NIR excitation allows photochemical control over NO release. Low doses reduce levels of hypoxia inducible factor 1 alpha (HIF-1α) in the tumor cells, while high doses are cytotoxic. The use of macrophages to carry microparticles with a NIR photo-activated theranostic payload into a tumor overcomes challenges often faced with therapeutic administration of NO and offers the potential of multiple treatment strategies with a single system.
Daniel C Pan, Jacob W Myerson, Jacob S Brenner, Priyal N Patel, Aaron C Anselmo, Samir Mitragotri, and Vladimir Muzykantov. 2018. “Nanoparticle Properties Modulate Their Attachment and Effect on Carrier Red Blood Cells.” Sci Rep, 8, 1, Pp. 1615.Abstract
Attachment of nanoparticles (NPs) to the surface of carrier red blood cells (RBCs) profoundly alters their interactions with the host organism, decelerating NP clearance from the bloodstream while enabling NP transfer from the RBC surface to the vascular cells. These changes in pharmacokinetics of NPs imposed by carrier RBCs are favorable for many drug delivery purposes. On the other hand, understanding effects of NPs on the carrier RBCs is vital for successful translation of this novel drug delivery paradigm. Here, using two types of distinct nanoparticles (polystyrene (PSNP) and lysozyme-dextran nanogels (LDNG)) we assessed potential adverse and sensitizing effects of surface adsorption of NPs on mouse and human RBCs. At similar NP loadings (approx. 50 particles per RBC), adsorption of PSNPs, but not LDNGs, induces RBCs agglutination and sensitizes RBCs to damage by osmotic, mechanical and oxidative stress. PSNPs, but not LDNGs, increase RBC stiffening and surface exposure of phosphatidylserine, both known to accelerate RBC clearance in vivo. Therefore, NP properties and loading amounts have a profound impact on RBCs. Furthermore, LDNGs appear conducive to nanoparticle drug delivery using carrier RBCs.
Aaron C Anselmo, Yatin Gokarn, and Samir Mitragotri. 2018. “Non-invasive delivery strategies for biologics.” Nat Rev Drug Discov.Abstract
Biologics now constitute a significant element of available medical treatments. Owing to their clinical and commercial success, biologics are a rapidly growing class and have become a dominant therapeutic modality. Although most of the successful biologics to date are drugs that bear a peptidic backbone, ranging from small peptides to monoclonal antibodies (~500 residues; 150 kDa), new biologic modalities, such as nucleotide-based therapeutics and viral gene therapies, are rapidly maturing towards widespread clinical use. Given the rise of peptides and proteins in the pharmaceutical landscape, tremendous research and development interest exists in developing less-invasive or non-invasive routes for the systemic delivery of biologics, including subcutaneous, transdermal, oral, inhalation, nasal and buccal routes. This Review summarizes the current status, latest updates and future prospects for such delivery of peptides, proteins and other biologics.
Jacob S Brenner, Daniel C Pan, Jacob W Myerson, Oscar A Marcos-Contreras, Carlos H Villa, Priyal Patel, Hugh Hekierski, Shampa Chatterjee, Jian-Qin Tao, Hamideh Parhiz, Kartik Bhamidipati, Thomas G Uhler, Elizabeth D Hood, Raisa Yu Kiseleva, Vladimir S Shuvaev, Tea Shuvaeva, Makan Khoshnejad, Ian Johnston, Jason V Gregory, Joerg Lahann, Tao Wang, Edward Cantu, William M Armstead, Samir Mitragotri, and Vladimir Muzykantov. 2018. “Red blood cell-hitchhiking boosts delivery of nanocarriers to chosen organs by orders of magnitude.” Nat Commun, 9, 1, Pp. 2684.Abstract
Drug delivery by nanocarriers (NCs) has long been stymied by dominant liver uptake and limited target organ deposition, even when NCs are targeted using affinity moieties. Here we report a universal solution: red blood cell (RBC)-hitchhiking (RH), in which NCs adsorbed onto the RBCs transfer from RBCs to the first organ downstream of the intravascular injection. RH improves delivery for a wide range of NCs and even viral vectors. For example, RH injected intravenously increases liposome uptake in the first downstream organ, lungs, by ~40-fold compared with free NCs. Intra-carotid artery injection of RH NCs delivers >10% of the injected NC dose to the brain, ~10× higher than that achieved with affinity moieties. Further, RH works in mice, pigs, and ex vivo human lungs without causing RBC or end-organ toxicities. Thus, RH is a clinically translatable platform technology poised to augment drug delivery in acute lung disease, stroke, and several other diseases.
Amrita Banerjee, Kelly Ibsen, Tyler Brown, Renwei Chen, Christian Agatemor, and Samir Mitragotri. 2018. “Reply to Rogers and Gurau: Definitions of ionic liquids and deep eutectic solvents.” Proc Natl Acad Sci U S A, 115, 47, Pp. E11000-E11001.
Douglas R Vogus, Anusha Pusuluri, Renwei Chen, and Samir Mitragotri. 2018. “Schedule dependent synergy of gemcitabine and doxorubicin: Improvement of in vitro efficacy and lack of in vitro-in vivo correlation.” Bioeng Transl Med, 3, 1, Pp. 49-57.Abstract
Combination chemotherapy is commonly used to treat late stage cancer; however, treatment is often limited by systemic toxicity. Optimizing drug ratio and schedule can improve drug combination activity and reduce dose to lower toxicity. Here, we identify gemcitabine (GEM) and doxorubicin (DOX) as a synergistic drug pair in vitro for the triple negative breast cancer cell line MDA-MB-231. Drug synergy and caspase activity were increased the most by exposing cells to GEM prior to DOX in vitro. While the combination was more effective than the single drugs at inhibiting MDA-MB-231 growth in vivo, the clear schedule dependence observed in vitro was not observed in vivo. Differences in drug exposure and cellular behavior in vivo compared to in vitro are likely responsible. This study emphasizes the importance in understanding how schedule impacts drug synergy and the need to develop more advanced strategies to translate synergy to the clinic.
Zongmin Zhao, Anvay Ukidve, Anshuman Dasgupta, and Samir Mitragotri. 2018. “Transdermal immunomodulation: Principles, advances and perspectives.” Adv Drug Deliv Rev, 127, Pp. 3-19.Abstract
Immunomodulation, manipulation of the immune responses towards an antigen, is a promising strategy to treat cancer, infectious diseases, allergies, and autoimmune diseases, among others. Unique features of the skin including the presence of tissue-resident immune cells, ease of access and connectivity to other organs makes it a unique target organ for immunomodulation. In this review, we summarize advances in transdermal delivery of agents for modulating the immune responses for vaccination as well as tolerization. The biological foundation of skin-based immunomodulation and challenges in its implementation are described. Technological approaches aimed at enhancing the delivery of immunomodulatory therapeutics into skin are also discussed in this review. Progress made in the treatment of several specific diseases including cancer, infections and allergy are discussed. Finally, this review discusses some practical considerations and offers some recommendations for future studies in the field of transdermal immunomodulation.
Eden EL Tanner, Kelly N Ibsen, and Samir Mitragotri. 2018. “Transdermal insulin delivery using choline-based ionic liquids (CAGE).” J Control Release, 286, Pp. 137-144.Abstract
Transdermal delivery of pharmaceuticals using ionic liquids and deep eutectic solvents (DES) has attracted significant interest due to the inherent tunability of the molecules and their capacity to transport large molecules across the skin. Several key properties of DESs including viscosity, miscibility and possible transport enhancement can be controlled through the choice of ions and their ratio in DES. Herein we investigate the effect of cation/anion ratio using Choline and Geranic acid (CAGE) based DES. We synthesized variants of CAGE by controlling the ratio of Choline to Geranic acid over a range of 1:4 to 2:1. Physicochemical properties including viscosity, conductivity and diffusivity were measured. Effect of CAGE on skin permeability was assessed using insulin in ex vivo porcine skin. Each variant was found to have distinct properties, including interionic interactions, viscosity, and conductivity. In addition, the effect of CAGE on stratum corneum lipids, as assessed by FTIR, was dependent on its composition. Transport enhancement was also composition-dependent, as the variants containing excess geranic acid (1:2 and 1:4, but not geranic acid alone) exhibited higher insulin delivery into the dermis compared to other compositions, demonstrating the importance of investigating the effect of ion ratios on drug delivery.
2017
Douglas R Vogus, Vinu Krishnan, and Samir Mitragotri. 9/2017. “A review on engineering polymer drug conjugates to improve combination chemotherapy.” Current Opinion in Colloid & Interface Science, 31, Pp. 75-85. Publisher's VersionAbstract
Combination chemotherapy treatments with polymer drug conjugates(PDCs) have been designed to overcome the limitations of traditional chemotherapy. While there are many significant design challenges associated with engineering a combination therapy with PDCs, several studies have shown therapeutic benefits of incorporating multiple drugs onto a polymeric carrier. Here, we summarize the chemistries and biological performance of different combination PDCs that have been tested in the preclinical setting and offer recommendations for future studies which will provide the necessary information to streamline future translation.
Peter Popp Wibroe, Aaron C Anselmo, Per H Nilsson, Apoorva Sarode, Vivek Gupta, Rudolf Urbanics, Janos Szebeni, Alan Christy Hunter, Samir Mitragotri, Tom Eirik Mollnes, and Seyed Moein Moghimi. 2017. “Bypassing adverse injection reactions to nanoparticles through shape modification and attachment to erythrocytes.” Nat Nanotechnol, 12, 6, Pp. 589-594.Abstract
Intravenously injected nanopharmaceuticals, including PEGylated nanoparticles, induce adverse cardiopulmonary reactions in sensitive human subjects, and these reactions are highly reproducible in pigs. Although the underlying mechanisms are poorly understood, roles for both the complement system and reactive macrophages have been implicated. Here, we show the dominance and importance of robust pulmonary intravascular macrophage clearance of nanoparticles in mediating adverse cardiopulmonary distress in pigs irrespective of complement activation. Specifically, we show that delaying particle recognition by macrophages within the first few minutes of injection overcomes adverse reactions in pigs using two independent approaches. First, we changed the particle geometry from a spherical shape (which triggers cardiopulmonary distress) to either rod- or disk-shape morphology. Second, we physically adhered spheres to the surface of erythrocytes. These strategies, which are distinct from commonly leveraged stealth engineering approaches such as nanoparticle surface functionalization with poly(ethylene glycol) and/or immunological modulators, prevent robust macrophage recognition, resulting in the reduction or mitigation of adverse cardiopulmonary distress associated with nanopharmaceutical administration.
Samir Mitragotri, Twan Lammers, You Han Bae, Steven Schwendeman, Stefaan De Smedt, Jean-Christophe Leroux, Dan Peer, Ick Chan Kwon, Hideyoshi Harashima, Akihiko Kikuchi, Yu-Kyoung Oh, Vladmir Torchilin, Wim Hennink, Justin Hanes, and Kinam Park. 2017. “Drug Delivery Research for the Future: Expanding the Nano Horizons and Beyond.” J Control Release, 246, Pp. 183-184.
Jia Niu, David J Lunn, Anusha Pusuluri, Justin I Yoo, Michelle A O'Malley, Samir Mitragotri, Tom H Soh, and Craig J Hawker. 2017. “Engineering live cell surfaces with functional polymers via cytocompatible controlled radical polymerization.” Nat Chem, 9, 6, Pp. 537-545.Abstract
The capability to graft synthetic polymers onto the surfaces of live cells offers the potential to manipulate and control their phenotype and underlying cellular processes. Conventional grafting-to strategies for conjugating preformed polymers to cell surfaces are limited by low polymer grafting efficiency. Here we report an alternative grafting-from strategy for directly engineering the surfaces of live yeast and mammalian cells through cell surface-initiated controlled radical polymerization. By developing cytocompatible PET-RAFT (photoinduced electron transfer-reversible addition-fragmentation chain-transfer polymerization), synthetic polymers with narrow polydispersity (M/M < 1.3) could be obtained at room temperature in 5 minutes. This polymerization strategy enables chain growth to be initiated directly from chain-transfer agents anchored on the surface of live cells using either covalent attachment or non-covalent insertion, while maintaining high cell viability. Compared with conventional grafting-to approaches, these methods significantly improve the efficiency of grafting polymer chains and enable the active manipulation of cellular phenotypes.
Douglas R Vogus, Michael A Evans, Anusha Pusuluri, Alexandra Barajas, Mengwen Zhang, Vinu Krishnan, Maksymilian Nowak, Stefano Menegatti, Matthew E Helgeson, Todd M Squires, and Samir Mitragotri. 2017. “A hyaluronic acid conjugate engineered to synergistically and sequentially deliver gemcitabine and doxorubicin to treat triple negative breast cancer.” J Control Release, 267, Pp. 191-202.Abstract
Combination chemotherapy is commonly used to treat advanced breast cancer. However, treatment success is often limited due to systemic toxicity. To improve therapeutic efficacy, polymer drug conjugates carrying synergistic pairs of chemotherapy drugs can be used to reduce drug administration dose. Here, we systematically evaluated the effect of temporal scheduling of doxorubicin (DOX) and gemcitabine (GEM) on drug synergy. Hyaluronic acid (HA) drug conjugates with distinct linkers conjugating both DOX and GEM were synthesized to control relative release kinetics of each drug. We show that polymer conjugates that release GEM faster than DOX are more effective at killing triple negative breast cancer cells in vitro. We further show that the optimal dual drug conjugate more effectively inhibits the growth of an aggressive, orthotopic 4T1 tumor model in vivo than free DOX and GEM and the single drug HA conjugates. The dual drug HA conjugate can inhibit 4T1 tumor growth in vivo during treatment through both intravenous and non-local subcutaneous injections. These results emphasize the importance of understanding the effect release rates have on the efficacy of synergistic drug carriers and motivate the use of HA as a delivery platform for multiple cancer types.
Dong Li, Jie Zhuang, Haisheng He, Sifan Jiang, Amrita Banerjee, Yi Lu, Wei Wu, Samir Mitragotri, Li Gan, and Jianping Qi. 2017. “Influence of Particle Geometry on Gastrointestinal Transit and Absorption following Oral Administration.” ACS Appl Mater Interfaces, 9, 49, Pp. 42492-42502.Abstract
Geometry has been considered as one of the important parameters in nanoparticle design because it affects cellular uptake, transport across the physiological barriers, and in vivo distribution. However, only a few studies have been conducted to elucidate the influence of nanoparticle geometry in their in vivo fate after oral administration. This article discloses the effect of nanoparticle shape on transport and absorption in gastrointestinal (GI) tract. Nanorods and nanospheres were prepared and labeled using fluorescence resonance energy transfer molecules to track the in vivo fate of intact nanoparticles accurately. Results demonstrated that nanorods had significantly longer retention time in GI tract compared with nanospheres. Furthermore, nanorods exhibited stronger ability of penetration into space of villi than nanospheres, which is the main reason of longer retention time. In addition, mesenteric lymph transported 1.75% nanorods within 10 h, which was more than that with nanospheres (0.98%). Fluorescent signals arising from nanoparticles were found in the kidney but not in the liver, lung, spleen, or blood, which could be ascribed to low absorption of intact nanoparticles. In conclusion, nanoparticle geometry influences in vivo fate after oral delivery and nanorods should be further investigated for designing oral delivery systems for therapeutic drugs, vaccines, or diagnostic materials.

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