A. James Clark School of Engineering

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The collections in this community comprise faculty research works, as well as graduate theses and dissertations.

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Subject: search.filters.subject.ICAM-1

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    Tuning Design Parameters of ICAM-1-Targeted 3DNA Nanocarriers to Optimize Pulmonary Targeting Depending on Drug Type
    (MDPI, 2022-07-19) Roki, Nikša; Solomon, Melani; Bowers, Jessica; Getts, Lori; Getts, Robert C.; Muro, Silvia
    3DNA holds promise as a carrier for drugs that can be intercalated into its core or linked to surface arms. Coupling 3DNA to an antibody targeting intercellular adhesion molecule 1 (ICAM-1) results in high lung-specific biodistributions in vivo. While the role of individual parameters on ICAM-1 targeting has been studied for other nanocarriers, it has never been examined for 3DNA or in a manner capable of revealing the hierarchic interplay among said parameters. In this study, we used 2-layer vs. 4-layer anti-ICAM 3DNA and radiotracing to examine biodistribution in mice. We found that, below saturating conditions and within the ranges tested, the density of targeting antibodies on 3DNA is the most relevant parameter driving lung targeting over liver clearance, compared to the number of antibodies per carrier, total antibody dose, 3DNA dose, 3DNA size, or the administered concentration, which influenced the dose in organs but not the lung specific-over-liver clearance ratio. Data predicts that lung-specific delivery of intercalating (core loaded) drugs can be tuned using this biodistribution pattern, while that of arm-linked (surface loaded) drugs requires a careful parametric balance because increasing anti-ICAM density reduces the number of 3DNA arms available for drug loading.
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    IN VIVO BIODISTRIBUTION, LUNG TARGETING, AND PARAMETRIC MODULATION OF A DNA-BASED DRUG DELIVERY SYSTEM ADDRESSED TO ICAM-1
    (2020) Roki, Niksa; Muro, Silvia; Bentley, William; Bioengineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The design goal of ligand-targeted nanoparticles (NPs) is to achieve site-specific targeting to specific biological targets, which can maximize therapeutic efficacy and safety. However, site-specific delivery remains suboptimal due to biological barriers, particularly non-specific interactions and sequestration of NPs by the immune system and anatomic structures of clearance organs in vivo. This formidable challenge prompted the exploration of novel ligand-based NP designs. Due to their exceptional precision, versatility, and biocompatibility, NPs composed of DNA (DNA-NPs) and targeted via ligands, have emerged as a promising strategy to deliver therapeutic effects with unique precision. One such formulation is anti-ICAM/3DNA, a multibranched DNA-made nanocarrier (3DNA®) functionalized with antibodies (Abs) against intercellular adhesion molecule-1 (ICAM-1), a cell surface glycoprotein accessible for targeting from the bloodstream and overexpressed in the lungs in many diseases. In particular, a prototype formulation of anti-ICAM/3DNA had demonstrated high cell-specific targeting and therapeutic potential in vitro. In this dissertation, we explored the kinetics, biodistribution, and lung-specific targeting in vivo of a new anti-ICAM/3DNA design that enabled precise surface functionalization with Abs to provide and modulate targeting. In Aim 1, we modified a radiotracing-based method to correct 125I-NP biodistribution results by separating the signal arising from the free 125I label, providing more accurate measurements of the NP biodistribution. In Aim 2, intravenous injection of anti-ICAM/3DNA in mice resulted in profuse and specific lung targeting, which had an unprecedently high specificity index over non-specific control. In Aim 3, we demonstrated that below the lung delivery saturation conditions and within the parametric range tested, anti-ICAM density on 3DNA played a key role in modulating lung specificity compared to the dose concentration and size of anti-ICAM/3DNA. Additionally, we estimated how this would impact targeting of drugs that can be intercalated into the DNA carrier core or linked to carrier outer arms. Overall, this study demonstrates that anti-ICAM/3DNA bio-physicochemical properties allow for efficient, specific, and tunable lung targeting. This new knowledge will help guide future DNA-NP designs for targeted therapeutic delivery and set the basis for investigational applications aimed at the treatment of pulmonary diseases.
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    Investigation of Vesicular-Mediated Transport of Intercellular Adhesion Molecule-1-Targeted Carriers for Treatment of Lysosomal Storage Disorders
    (2017) Manthe, Rachel Lee; Muro, Silvia; Bioengineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Numerous cellular processes and therapeutic interventions rely on vesicular-mediated endocytosis to gain entry into cells and sub-cellular compartments, as well as for transcellular transport across biological barriers such as found at the blood-brain interface. Yet, endocytic behavior can be altered in disease, representing an additional hurdle in the design of effective therapeutic strategies. Lysosomal storage disorders (LSDs), characterized by lysosomal accumulation of undigested substrates as a result of deficient enzymatic activity, illustrate this paradigm. Currently, intravenous infusion of recombinant lysosomal enzymes to replace those deficient is the standard clinical approach for these disorders. However, clathrin-mediated endocytosis utilized by replacement enzymes for cellular uptake and lysosomal trafficking is altered, thereby impacting treatment efficacy as recently demonstrated in acid sphingomyelinase-deficient type A Niemann-Pick disease (NPD). Therefore, alternative means to bypass defunct routes is warranted. Therapeutic delivery via polymer nanocarriers targeting intercellular adhesion molecule-1 (anti-ICAM NCs), a cell-surface molecule overexpressed in endothelial and subjacent tissue cells during inflammation, such as in LSDs, represents a viable option since it permits uptake, intra- and transcellular transport via a unique endocytic route called the cell adhesion molecule (CAM) pathway. In this dissertation, cell culture and animal models were used to examine the (1) endocytic activity of the CAM pathway and other clathrin-independent routes in type A NPD, (2) role of targeting valency (i.e., density of ICAM-1-targeting molecules on the NC surface) in regulating the CAM pathway, and (3) effects induced via engagement of ICAM-1 on cells by anti-ICAM NCs. The results herein demonstrate the CAM pathway is more active in diseased cells compared to other classical endocytic pathways, making it the most amenable route for therapeutic enzyme replacement. Further, modulating targeting valency of NCs optimized this strategy for enhanced enzyme delivery to the brain, a target organ for type A NPD. Lastly, anti-ICAM NCs attenuated endothelial release of soluble ICAM-1, an inflammatory regulator, representing a secondary benefit of this system. Overall, this work validates utility of anti-ICAM NCs for enzyme replacement to treat NPD and likely other LSDs, and provides insight into biological processes and design parameters that influence the therapeutic efficacy of targeted drug carriers.
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    Investigation of Intercellular Adhesion Molecule-1 Targeted Drug Transport Across the Gastrointestinal Epithelium
    (2015) Ghaffarian, Rasa; Muro, Silvia; Bioengineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Contrary to systemic injection of therapeutics, oral formulations represent clear advantages to patients, healthcare systems, and pharmaceutical companies including safety, low cost and patient compliance. However, oral delivery remains a major obstacle due to (1) drug instability in the harsh environment of the gastrointestinal (GI) tract owing to low gastric pH and enzymatic hydrolysis; (2) low permeability through the mucus layer and subsequent adhesion to the GI epithelium; and (3) suboptimal transport into or across the GI epithelium- the cell barrier responsible for selective absorption of substances into the circulation, for local or systemic delivery. While encapsulation methods have been developed to overcome barriers to stability and adhesion to the GI epithelium, safe and effective transport into and across this lining has not yet been achieved for several drugs, especially biotherapeutics. Hence, our goal is to overcome these challenges for delivery of therapeutics (including biotherapeutics) via the oral route. For this purpose, we targeted drugs to intercellular adhesion molecule-1 (ICAM-1), a protein expressed on the GI epithelium and other cell types. We previously demonstrated, that polymer nanocarriers (NCs) coated with antibodies to bind multiple copies of ICAM-1 (multimeric targeting) triggered uptake and transport across cultured GI epithelial cells, enabling intracellular and transcellular drug delivery. To implement this strategy in vivo, we successfully encapsulated antibody-coated NCs in chitosan-alginate microspheres for gastric protection of labile targeting antibodies, site-specific release in the intestinal environment (the site of drug absorption) and retention of targeting ability following release in vitro, in cell culture, and in vivo. Furthermore, to expand the utility of the ICAM-1 targeting approach, we explored a novel drug delivery system that binds only one to two molecules of ICAM-1 (monomeric targeting), which provides distinct advantages for oral drug delivery compared with multimeric strategies. In order to elucidate the advantages offered by this monomeric targeting approach, we compared the uptake and intracellular trafficking of ICAM-1 targeted monomeric antibodies vs. multimeric antibody-coated NCs in cultured endothelial cells, a commonly used cellular model to study ICAM-1 transport. We then revealed that the distinct itinerary of transport offered by monomeric ICAM-1 targeted antibodies led to enhanced uptake and transport across cultured GI epithelial cells, showing promise for oral delivery. Finally, in order to exploit this transport pathway for oral drug delivery, we conjugated a model drug cargo to monomeric ICAM-1 targeted antibodies, which was shown to endow drug targeting and delivery into and across cultured GI epithelial cells, while preserving the functional activity of the drug cargo. These findings demonstrate that monomeric vehicles serve as a viable alternative to multimeric strategies, expanding the range of oral delivery applications afforded by ICAM-1 targeting. Taken together, the work performed in this dissertation advocates the potential of ICAM-1 targeting strategies for improving oral absorption of therapeutics, and provides a foundation for studying these strategies in vivo.