The use of polysaccharides as building blocks in the development of drugs and contrast agents delivery systems is rapidly growing. This can be attributed to the outstanding virtues of polysaccharides such as biocompatibility, biodegradability, upgradability, multiple reacting groups and low cost. The focus of this thesis was to develop and characterize novel starch based hydrogels and nanoparticles for delivery of drugs and imaging agents. To this end, two different systems were developed. The first system includes polymer and nanoparticles prepared by graft polymerization of polymethacrylic acid and polysorbate 80 onto starch. This starch based platform nanotechnology was developed using the design principles based on the pathophysiology of breast cancer, with applications in both medical imaging and breast cancer chemotherapy. The nanoparticles exhibited a high degree of doxorubicin loading as well as sustained pH dependent release of the drug. The drug loaded nanoparticles were significantly more effective against multidrug resistant human breast cancer cells compared to free doxorubicin. Systemic administration of the starch based nanoparticles co-loaded with doxorubicin and a near infrared fluorescent probe allowed for non-invasive real time monitoring of the nanoparticles biodistribution, tumor accumulation, and clearance. Systemic administration of the clinically relevant doses of the drug loaded particles to a mouse model of breast cancer significantly enhanced therapeutic efficacy while minimizing side effects compared to free doxorubicin. A novel, starch based magnetic resonance imaging (MRI) contrast agent with good in vitro and in vivo tolerability was formulated which exhibited superior signal enhancement in tumor and vasculature. The second system is a co-polymeric hydrogel of starch and xanthan gum with adjustable swelling and permeation properties. The hydrogels exhibited excellent film forming capability, and appeared to be particularly useful in controlled delivery applications of larger molecular size compounds. The starch based hydrogels, polymers and nanoparticles developed in this work have shown great potentials for controlled drug delivery and biomedical imaging applications.

The use of polysaccharides as building blocks in the development of drugs and contrast agents delivery systems is rapidly growing. This can be attributed to the outstanding virtues of polysaccharides such as biocompatibility, biodegradability, upgradability, multiple reacting groups and low cost. The focus of this thesis was to develop and characterize novel starch based hydrogels and nanoparticles for delivery of drugs and imaging agents. To this end, two different systems were developed. The first system includes polymer and nanoparticles prepared by graft polymerization of polymethacrylic acid and polysorbate 80 onto starch. This starch based platform nanotechnology was developed using the design principles based on the pathophysiology of breast cancer, with applications in both medical imaging and breast cancer chemotherapy. The nanoparticles exhibited a high degree of doxorubicin loading as well as sustained pH dependent release of the drug. The drug loaded nanoparticles were significantly more effective against multidrug resistant human breast cancer cells compared to free doxorubicin. Systemic administration of the starch based nanoparticles co-loaded with doxorubicin and a near infrared fluorescent probe allowed for non-invasive real time monitoring of the nanoparticles biodistribution, tumor accumulation, and clearance. Systemic administration of the clinically relevant doses of the drug loaded particles to a mouse model of breast cancer significantly enhanced therapeutic efficacy while minimizing side effects compared to free doxorubicin. A novel, starch based magnetic resonance imaging (MRI) contrast agent with good in vitro and in vivo tolerability was formulated which exhibited superior signal enhancement in tumor and vasculature. The second system is a co-polymeric hydrogel of starch and xanthan gum with adjustable swelling and permeation properties. The hydrogels exhibited excellent film forming capability, and appeared to be particularly useful in controlled delivery applications of larger molecular size compounds. The starch based hydrogels, polymers and nanoparticles developed in this work have shown great potentials for controlled drug delivery and biomedical imaging applications.

<p>Recent advances in nanotechnology have led to the application of nanoparticles in a wide variety of fields. In the field of nanomedicine, there is great emphasis on combining diagnostic and therapeutic modalities into a single nanoparticle construct (theranostics). In particular, anisotropic nanoparticles have shown great potential for surface-enhanced Raman scattering (SERS) detection due to their unique optical properties. Gold nanostars are a type of anisotropic nanoparticle with one of the highest SERS enhancement factors in a non-aggregated state. By utilizing the distinct characteristics of gold nanostars, new plasmonic materials for diagnostics, therapy, and sensing can be synthesized. The work described herein is divided into two main themes. The first half presents a novel, theranostic nanoplatform that can be used for both SERS detection and photodynamic therapy (PDT). The second half involves the rational design of silver-coated gold nanostars for increasing SERS signal intensity and improving reproducibility and quantification in SERS measurements. </p><p>The theranostic nanoplatforms consist of Raman-labeled gold nanostars coated with a silica shell. Photosensitizer molecules for PDT can be loaded into the silica matrix, while retaining the SERS signal of the gold nanostar core. SERS detection and PDT are performed at different wavelengths, so there is no interference between the diagnostic and therapeutic modalities. Singlet oxygen generation (a measure of PDT effectiveness) was demonstrated from the drug-loaded nanocomposites. In vitro testing with breast cancer cells showed that the nanoplatform could be successfully used for PDT. When further conjugating the nanoplatform with a cell-penetrating peptide (CPP), efficacy of both SERS detection and PDT is enhanced. </p><p>The rational design of plasmonic nanoparticles for SERS sensing involved the synthesis of silver-coated gold nanostars. Investigation of the silver coating process revealed that preservation of the gold nanostar tips was necessary to achieve the increased SERS intensity. At the optimal amount of silver coating, the SERS intensity is increased by over an order of magnitude. It was determined that a majority of the increased SERS signal can be attributed to reducing the inner filter effect, as the silver coating process moves the extinction of the particles far away from the laser excitation line. To improve reproducibility and quantitative SERS detection, an internal standard was incorporated into the particles. By embedding a small-molecule dye between the gold and silver surfaces, SERS signal was obtained both from the internal dye and external analyte on the particle surface. By normalizing the external analyte signal to the internal reference signal, reproducibility and quantitative analysis are improved in a variety of experimental conditions.</p> / Dissertation

Engineered nanoparticles provide potential opportunities for improving current drug delivery, bioimaging and biosensing modalities. In many cases, a ligand, such as a protein, peptide or nucleic acids, is attached to the nanoparticles surface to serve as a targeting group. However, the nanoconjugation (i.e. covalently bound molecules to a nanocarrier) is not an innocuous reaction. It can change the binding affinity and interfere with the intracellular trafficking of the tethered species. The understanding of this influence to the tethered species is still lacking. Therefore, the main objective of this thesis is to investigate the effect of nanoconjugation to the biological identity of the tethered biomolecules, in terms of cellular uptake, intracellular trafficking and the ultimate biological outcomes. The Epidermal Growth Factor Receptor (EGFR) is a tyrosine kinase that regulates cell proliferation and can cause cancer if dysregulated. Continuous treatment with high doses of EGF can induce apoptosis, in EGFR overexpressing cell lines. In this thesis, Epidermal Growth Factor (EGF) was chosen as the object of investigation. Covalent attachment of EGF to gold nanoparticles (NP-EGF) was found to enhance apoptosis in EGFR overexpressing cell lines (A431, MDA-MB-468) and it is sufficient to induce apoptosis in cell lines exhibiting EGFR expression at physiological levels (HeLa). NP-EGF accumulation through the endosomal pathway was also investigated to assess the impact of nanoconjugation on the spatio-temporal distribution of NP-EGF as potential origin for the observed enhancement of apoptosis. Two orthogonal experimental approaches were applied: (1) isolation of NP-EGF containing endosomes by taking advantage of the increased density of endosomes associated with the uptake of Au NPs; (2) correlated darkfield/fluorescence imaging to map the spatial distribution of NP-EGF in endosomes as a function of time. The studies reveal that nanoconjugation prolongs the dwelling time of phosphorylated receptors in the early endosomes and that the retention of activated EGFR in the early endosomes is accompanied by an EGF mediated apoptosis at effective concentrations that do not induce apoptosis in the case of the free EGF. Investigating the nanoconjugation-enhanced EGF-induced apoptosis improves the current understanding of cell-nanomatieral interactions and provides new opportunities for overcoming apoptosis evasion by cancer cells. / 2017-01-01T00:00:00Z

Near-infrared dyes can be used as theranostic agents in cancer management based on their optical imaging and localized hyperthermia capabilities. However, their clinical translatability is limited by issues such as photobleaching, short circulation times, and non-specific biodistribution. We studied the applications of IR820 in optical imaging and hyperthermia, and we prepared nanoconjugate formulations to overcome some of the aforementioned limitations. Free IR820 can be used for optical imaging, with a strong signal still present 24 hours after i.v. injection, an elimination plasma half-life in the order of hours, and primary biodistribution to liver, lung, and kidneys. After 808-mn laser exposure, IR820 can also raise in vitro temperatures to the 41-43°C range that can selectively inhibit cancer cell growth. We conjugated IR820 with PEG-diamine via ionic interactions to create nanoconjugates (IR820-PDNCs) with diameters of approximately 50-nm per SEM and a zeta potential of 2.0±0.9 mV. IR820-PDNCs enhanced cellular internalization compared to IR820 for imaging in SKOV-3, MES-SA, and Dx5 cancer cells. The nanoconjugates also significantly enhanced hyperthermia-mediated cytotoxicity in MES-SA and Dx5 compared to the free dye (p

Master thesis deals with the use of bacteriophage as a theranostic drug nanocarrier. The term theranostics is used in recent years for systems that allow connecting of diagnostics, targeted drug delivery and monitoring of patient’s response to administered treatment in a single modality. These systems are very suitable especially with heterogeneous diseases, such as cancer. Nowadays, the treatment of cancer has often severe side effects to the patient’s body, which lowers his capability to fight the disease. Theoretical part of this work is focused on the properties of viral capsids, proteins and inorganic materials as drug nanocarriers. In practical part of this work, different methods for cultivation of bacteriophage are compared, both in liquid and solid medium and with different concentrations of the maltose, trough whose receptors bacteriophage is able to enter the host cell. Optimal was cultivation with 0.2% maltose in solid medium. Practical part is focused mainly on the use of bacteriophage as a nanocarrier for cytotoxic drug doxorubicin. Bacteriophage was able to encapsulate all applied concentrations of doxorubicin (0; 12.5; 25; 50; 100 and 200 g/ml), which was proved using fluorescent detection. Different times of encapsulation (2; 4; 8 and 12 hours) were studied. Optimal time was 2 hours. Encapsulation properties of bacteriophage were compared to apoferritin. Bacteriophage was able to encapsulate 4× higher concentrations of doxorubicin and its release during rinsing with water was 10× lower compared to apoferritin. This work concludes that bacteriophage is a very suitable platform for targeted drug delivery in theranostics.

Cancer is a leading case of mortality worldwide. Governments spent multibillion expenses on treatment and palliative care of diseased people. Despite these generous funding and intensive research with aim to find a cure or efficient treatment for cancer, until now there is a lack in selective cancer management strategies. Conventional treatment strategies for cancer, such as surgery, cytotoxic chemotherapy, radiation therapy, hormone therapy don’t have selectivity toward cancer – the property of discrimination of healthy organs and tissues from the diseased site. Chemotherapy is very challenging as the difference between effective and lethal doses is very minuscule in most cases. Moreover, devastating side effects dramatically changes the quality of life for cancer patients. To address these issues two main strategies are intensively utilized in chemistry: (I) the design and synthesis of novel anticancer organic compounds with higher selectivity and low toxicity profiles and the second, design and preparation of biocompatible nanocarriers for imaging and anticancer compound selective delivery nanomedicine. The following dissertation combines the above two strategies as bellows: First project is related to the design and synthetic route development toward novel nature-inspired group of heterocyclic compounds – iso-Phidianidines. The second project focused on design, preparation and evaluation of hybrid theranostics (therapeutic and diagnostic in a single entity). Chapter 1 is a general background review of the major topics that will be discussed in this dissertation. The first efficient and high-yielding synthetic route toward iso-phidianidines, containing regioisomeric form of 1,2,4-oxadiazole linked to the indole via methylene bridge is reported in Chapter 2. In vitro test of the synthesized library of iso-phidianidines revealed micromolar range of cytotoxicity toward human cervical cancer cell line. Structure activity relationship revealed the importance of presence of monosubsituted amine in 3 position of oxadiazole to maintain activity. Moreover, gradual increase of activity was detected in increasing of the length of the diamine. Polyamine (spermidine) side chain demonstrated strongest anticancer activity, identified as lead compound and may be studied further as a good candidate for cervical cancer treatment. Finally, the remaining high activity of amino-terminated iso-phidianidines demonstrated that presence of guanidine group in termini is not necessary for high cytotoxicity. The second part of this dissertation (Chapter 3) discusses the rational design, wet protocol synthesis and complete characterization of the novel hybrid material – polydopamine coated iron-cobalt nanocubes (PDFCs). This material was loaded with anticancer model drug doxorubicin in one step procedure (PDFC-DOX) and the resulting drug-delivery vehicle was found to be successfully internalized by cervical cancer cells. The cytotoxicity test demonstrated inhibition of 50% of the cells at the concentration of 30μg/ml for PDFC-DOX. Moreover, the release was highly attenuated and pH-sensitive in acidic range. PDFC was also modified with fluorescein leading to green fluorescent nanoparticles PDFC-FITC, which demonstrated excellent intracellular molecular imaging property. PDFCs with one of the highest magnetic saturation among the materials used in biomedicine (226 emu/g based on core) showed the absence of any cytotoxicity in vitro and excellent MRI contrasting property (r2=186.44 mMs-1, higher than commercial contrast agents Ferridex® and Clio®), both in vitro and in vivo on mice. They were cleared out from the mice bodies in month without affecting their health. Due to the high density of core (8.3 g/cm3) they demonstrated ability to be contrast materials also for X-Ray CT diagnostic modality, increasing the tumor detection and visualization probability in combination with MRI. In addition to it’s diagnostic and drug-delivery modalities, PDFC was evaluated also for microwave-induced cytotoxicity as a novel concept in cancer treatment. As low as 10 μg/ml concentration of PDFCs in human cervical cancer cells caused extensive death above 73% upon exposure to 2,45 GHz of microwaves for one minute. Laser irradiation (808 nm, 15 minutes) of cancer cells with internalized PDFCs caused cell death above 60%. The specific absorption rate of PDFCs at 470 MHz frequency and 20 mT of the alternating magnetic field power was 180 W/g, which is nearly 100 W higher than for commercial nanoparticles (Ferridex®).

La médecine se dirige de plus en plus vers des traitements personnalisés. Pour répondre à cela, les équipes de recherche ont développé des objets permettant de diagnostiquer et de soigner dans un temps restreint. Ceci a conduit à l’émergence d’un nouveau domaine : la théranostique (thérapie et diagnostic). Les nanoparticules sont une des réponses à ces problématiques. La mise au point de ces objets nécessite de maitriser parfaitement la taille, la morphologie et la composition chimique des particules. Les analogues de bleu de Prusse sont des polymères de coordination à ponts cyanures cristallins qui ont beaucoup été étudiés pour leurs propriétés magnétiques mais également pour des applications médicales. La taille nanométrique, la porosité de la structure, la présence de molécules d’eau et une grande versatilité chimique font de ces matériaux des candidats prometteurs pour un développement en tant qu’agent de contraste pour l’IRM. Ce réseau a également montré ces capacités en hyperthermie photoassistée. L’élaboration de nanoparticules de bleu de Prusse dopées par du GdIII ou du MnII et les études de leurs propriétés structurales et chimiques font partie des aspects développés au cours de ce travail de thèse. Les performances en relaxivité et en hyperthermie photoassistée ont pu être évaluées. Afin de mener des expériences in vivo, le comportement des objets dans les milieux adaptés a été exploré, ce qui a permis d’initier l’émergence d’un système optimal. Au cours de cette thèse, la stabilisation de colloïdes de polymères ide coordination incluant des ions PtII et PdII de type « cyanosols », ont été développés pour être notamment évalués en tant que radio-sensibilisateur en hadronthérapie. Ces objets amorphes permettent d’envisager de nombreuses combinaisons. Après la mise au point du protocole de synthèse, les caractérisations chimiques (taille, structure et compositions) ont permis de mettre en avant plusieurs systèmes à base de platine et de fer ainsi que de platine et d’or qui feront l’objet d’étude pour l’hadronthérapie. L’objectif est de faire de ces nouveaux polymères de coordination des nanoplateformes théranostiques alliant IRM et hadronthérapie. / Personal medicine is the future to treat cancer. To address this concern, researchers started to develop objects which can be effective for both diagnostic and treatment in a short time. A new domain has emerged: theranostic (therapy and diagnostic). Nanoparticles are a promising answer to this problematic. Synthesizing these objects implies to control size, morphology and chemical composition of the particles. Prussian blue analogues are coordination polymers with cyanide bridges which are considerable studied for their magnetic properties, but also for medical application. The size (nanometric), the porosity, the presence of water molecules and the high chemical versatility are the key argument to make Prussian blue good candidates as contrast agent for MRI. This network is also effective for photothermal therapy. Synthesis of Prussian blue doped with GdIII or MnII and study of the chemical and structural properties is one of the aspects developed during this thesis. Relaxivity and photothermal therapy performances have been measured. In order to conduct in vivo experiments, evolution of our nanoparticles in appropriate media have been evaluated which led to the development of an optimal system. During this thesis, new nanoparticles composed of heavy ions such as platinum or palladium, called cyanosols, have been elaborated to be used as radiosensitizers for hadrontherapy. Cyanosols are linked by cyanide bridge to other metallic ions. After the optimization of their synthesis, chemical characterization (size, structure and composition) was done to highlight some systems based, on platinum and iron as well as platinum and gold, which will be studied for hadrontherapy applications. The purpose of this future work is to create new theranostic nanoplatforms combining MRI and hadrontherapy.

京都大学 / 0048 / 新制・課程博士 / 博士(薬科学) / 甲第19973号 / 薬科博第64号 / 新制||薬科||7(附属図書館) / 33069 / 京都大学大学院薬学研究科薬科学専攻 / (主査)教授 橋田 充, 教授 佐治 英郎, 教授 髙倉 喜信 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

There is currently no solution for imaging fibrin-rich adhesions following surgery, yet the condition costs healthcare providers upwards of $2 billion annually. Over the past decade the development of ultrasound contrast agents has seen an increase in commercialization of generic microbubble formulations for standard diagnostic applications such as echocardiography. To enhance diagnostic power, molecularly targeted microbubbles are formulated with the addition of a ligand to the outer shell. The microbubble formulation must be modified so that the contrast agents are stable over time and targeted with the appropriate ligand while maintaining their echogenicity relative to surrounding soft tissue. We used a dual approach to look at microbubbles optically to predict their relative signal enhancement in vivo given their size distribution and concentration. An ImageJ macro script was developed based off BubblesizerJ, a previously developed open-source program. To confirm that modified microbubbles maintain acoustic properties relative to soft tissue, an agarose phantom model was developed that allows for high throughput testing of multiple microbubble formulations. / 2026-09-03T00:00:00Z