Multiple hurdles, such as drug solubility, stability, and physical barriers in the body, hinder bioavailability of many promising therapeutics. Polymeric nanocarriers can encapsulate the therapeutics to protect non-target areas from side effects but also protect the drug from premature degradation for increased circulation and bioavailability. To capitalize on these advantages, the polymer nanoparticle must be properly engineered for increased control in size distribution, therapeutic encapsulation, colloidal stability, and release kinetics. However, each application requires a specific set of characteristics and properties. Being able to tailor these by manipulation of different design parameters is essential to optimize nanoparticles for the application of interest. This study of nanoparticle fabrication and characterization takes us a step closer to building effective delivery systems tailored for specific treatments. Poly(ethylene oxide)-b-poly(D,L-lactic acid) (PEO-b-PDLLA) based nanoparticles were produced to range from 100-200 nm in size. They were fluorescently labeled with a hydrophobic dye 6-13 bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) at an optimal loading of 0.5 wt% with respect to the core. Surfaces were successfully coated with streptavidin to be readily functionalized with various biotinylated compounds such as PD-L1 antibodies or A488 fluorophore. Using the same PEO-b-PDLLA, iron oxide and a conjugated polymer poly(2- methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) were co-encapsulated to form fluorescently labeled magnetic particles. Using poly(lactic-co-glycolic acid), CRISPR-Cas9 plasmids were encapsulated at 1.6 wt% and most of the payload released within the first 24 hours. The incorporated plasmids were intact enough to have mammalian macrophages successfully express the bacterial protein Cas9. Using similar PLGA based particles, the surface was functionalized with streptavidin and bound to the surface of bacteria as an active carrier for increased penetration of solid tumors averaging ~23 particles per bacterium. PEO-b-PLGA based particles were used in conjunction with a hydrophobic salt former to encapsulate a peptide designed to reduce platelet binding to cancer cells and mitigate extravasation. The peptide encapsulated was increased from < 2 wt% without salt former to 8.5 wt% with the used of hexadecyl phosphonic acid. Although the applications across these projects can be broad, the fundamentals and important design parameters considered contribute to the overarching field of effective carriers for drug delivery. / Ph. D. / There are many reasons why many promising pharmaceutical formulations never make it through regulation and onto market, including low solubility of the drug, low absorbance by the body, and harmful side effects, to name a few. Using polymer drug carriers, these difficulties can be overcome by holding the drug in a more soluble carrier, releasing it on a certain timeline or to a specific location to increase absorbance and decrease side effects. When designing a carrier, the requirements for the product are dependent on the application and the disease of interest. This work looks at the material types and conditions during particle formation to see how it affects the final product to better define and understand how these parameters change the performance. This work shows that the carrier size can be manipulated depending on how much of one material is used versus the other, they can be labeled to fluoresce so they can be tracked during cell and animal studies, and they can be coated with targeting compounds on the surface to increase the specificity of the carrier to localize to a target location of interest. Different particles containing DNA for gene editing, peptides for cancer therapies, and magnetic iron oxides to increase transport across difficult cell barriers have all be fabricated and characterized. The lessons learned through these projects will help guide future work to more effective and efficient delivery of pharmaceuticals to the body.

This project introduces a novel ultrasonic shearing-based fabrication method for synthesizing nanobubbles, which can then be utilized as a platform for any theranostic applications in clinical medicine, such as drug/gene delivery systems. Our standard in situ sonochemical synthesis of nanobubbles incorporates a perfluorocarbon gas core (300 μl) and an albumin outer shell, which are then incorporated into phosphate-buffered saline (4 ml) and later sonicated with a US probe. The initial optimization phase consisted of experimenting with various amounts of human serum albumin (HSA), which stabilizes the nanobubble gas core. Of the parameters (20 mg, 40 mg, and 80 mg HSA), 40 mg HSA significantly outperformed (pin vivo imaging nanobubbles in the liver. A continuation of this project will continue to optimize and expand on the theranostic applications of the US sheared nanobubbles in vivo and ex vivo in osteoporosis and the bone.

No / Whereas protease inhibitors have been developed successfully against hypertension and viral infections, they have failed thus far as cancer drugs. With advances in cancer profiling we now better understand that the tumor “degradome” (i.e. the repertoire of proteases and their natural inhibitors and interaction partners) forms a complex network in which specific nodes determine the global outcome of manipulation of the protease web. However, knowing which proteases are active in the tumor micro-environment, we may tackle cancers with the use of Protease-Activated Prodrugs (PAPs). Here we exemplify this concept for metallo-, cysteine and serine proteases. PAPs not only exist as small molecular adducts, containing a cleavable substrate sequence and a latent prodrug, they are presently also manufactured as various types of nanoparticles. Although the emphasis of this review is on PAPs for treatment, it is clear that protease activatable probes and nanoparticles are also powerful tools for imaging purposes, including tumor diagnosis and staging, as well as visualization of tumor imaging during microsurgical resections.

No / channels that are critical for their development and function. Many ion channels contribute to T cell-mediated autoimmune and/or inflammatory responses, so they are attractive targets for pharmacological immune modulations. In this study, we conduct patch clamp experiments to exam the whole cell currents from lymphocytes after nanoparticles exposure with the aim to test if nanoparticles exposure brings any electrophysiological changes for lymphocytes, and to compare the electrophysiological responses of lymphocytes to drugs in nanoparticles forms. Our result suggests a potential inhibition of effects of IBU N on lymphocytes. Such cytotoxicity of nanoparticles in Lymphocytes may be mainly associated with the early membrane damage. These results are also mirrored by the DNA damages occurred on lymphocytes after exposure of nanoparticles. Further detailed investigation is needed to explain the changes of Lymphocytes in response to NPs in real time and dose differences. This would provide useful information in the evaluation of toxicology of nanoparticles and in understanding the underlying mechanism of their effects on ion channels in health and diseases.

Yes / Co-crystallization of polymers with different configurations/tacticities provides access to materials with enhanced performance. The stereocomplexation of isotactic poly(L-lactide) and poly(D-lactide) has led to improved properties compared with each homochiral material. Herein, we report the preparation of stereocomplex micelles from a mixture of poly(L-lactide)-b-poly(acrylic acid) and poly(D-lactide)-b-poly(acrylic acid) diblock copolymers in water via crystallization-driven self-assembly. During the formation of these stereocomplex micelles, an unexpected morphological transition results in the formation of dense crystalline spherical micelles rather than cylinders. Furthermore, mixture of cylinders with opposite homochirality in either THF/H2O mixtures or in pure water at 65 °C leads to disassembly into stereocomplexed spherical micelles. Similarly, a transition is also observed in a related PEO-b-PLLA/PEO-b-PDLA system, demonstrating wider applicability. This new mechanism for morphological reorganization, through competitive crystallization and stereocomplexation and without the requirement for an external stimulus, allows for new opportunities in controlled release and delivery applications. / University of Warwick, Swiss National Science Foundation and the EPSRC. The Royal Society - an Industry Fellowship to A.P.D. The Engineering and Physical Sciences Research Council (EP/G004897/1) - funding to support postdoctoral fellowships for A.P.B. as well as funding for J.S. and M.A.D. through the Warwick Centre for Analytical Science (EP/F034210/1). The Science City Research Alliance and the HEFCE Strategic Development Fund - funding support. Some items of equipment that were used in this research were funded by Birmingham Science City, with support from Advantage West Midlands and part-funded by the European Regional Development Fund.

Yes / FRET forms the basis for energy transfer in biological systems and organisms and it has become an investigative tool in the analysis of protein‐protein interactions and in the study of semiconductors (SC). Until now, FRET has been restricted to the simultaneous presence of both components in the same phase. Here, we report on the first successful prototype demonstrating interfacial FRET. This innovative FRET between inorganic SC‐nanoparticles and illuminating protein chimeras takes place across an oil/water interface. As a ′proof of concept′ oil droplets were stabilized by hydrophobin‐derivatives in aqueous solution. These proteins possess the ability to attach fused functional domains close to an interface. Moreover, an optically active nanostructure directly docks to the hydrophobin at the oil/water interface. Due to its modular design, this signal amplification array has the potential to be exploited in numerous fields ranging from biosensors, biotechnology to medical applications.

No / Nanoparticle usage has emerged in the medical field as a technology well-suited to the diagnosis and treatment of a variety of disease states. The distinctive characteristics of engineered nanoparticles (ENPs) such as higher surface-area-to-volume ratios find various applications in personal care products, food packaging, drug-delivery systems, therapeutics, biosensors and others. The exponential increase in ENP-containing consumer products in the last decade has also increased their inadvertent release into the environment and the debate relating to their adverse effects on human and environmental health. The use of NPs for different functions in human studies has significantly increased the application of NPs in biomedicine, for instance, imaging of cell and tissues, drug delivery and sensing of target molecules. These nanomaterials have been investigated for the treatment and detection of various pathological conditions. There are suitable biological systems now available in man using peripheral blood lymphocytes to determine the effect of NPs in various disease states.

With all the improvements in cancer treatments, multidrug resistance is still the major challenge in treating cancer. Cells can develop multidrug resistance (MDR) during or after treatment, which will render the cancer cells resistant not only to the chemotherapy drug being used but also to many other structurally- and mechanically-different chemotherapeutics. In the first project, the main focus was on development of drug resistant cell lines by selection with taxol. Gene changes in the L1T2 cell line after treatment with Taxol was studied. Treatment of L1T2 cells with taxol leads to changes in the expression of ABC transporter proteins, whereas the combination of Taxol with protease inhibitors leads to increased efficacy via inhibition of P-glycoprotein (P-gp). In the second project, we showed that our innovatively-designed Au-loaded poly(lactide-co-glycolic acid) nanoparticles (GPLGA NPs) are able to cross biological barriers and deliver inside the cells without being recognized by the ABC protein transporter. (We focus specifically on P-gp-mediated drug efflux in a model of HEK cell lines.) The concentration of gold was measured using inductively-coupled plasma/mass spectrometry (ICP-MS) after 6- and 24-hour treatment of GPLGA NPs, which did not show significant increase of gold inside the cells in presence of the P-gp inhibitor valspodar. Cancer cells were treated with the GPLGA NPs for 24 hours and then irradiated 5 minutes at 1Wcm-2 using laser settings at 680 or 808 nm. Heat generation in cancer cells, after internalizing GPLGA NPs and laser irradiation, was significant irrespective of laser wavelength. The plasmomic heating response in this in vitro model can be a step closer to overcome MDR. Finally, for the third and last project represented in this dissertation, the focus was on the design and synthesis of innovative, biodegradable PLGA NPs, encapsulated with the platinum(II)-based non-organometallic/non-cyclometalated phosphorescent complex PTA = [Pt(ptp)2], a brightly phosphorescent complex (ptp = square-planar bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]). Size-tunable, emission-polarized phosphorescent PTA-loaded PLGA NPs were synthesized using a single-emulsion, solvent evaporation technique. Photoluminescence characterization shows that PTA-loaded PLGA NPs exhibit strong and stable orange emission with peak maximum ~ 580 nm. The photoluminescence quantum yield (QY) of the synthesized PTA-PLGA NPs was evaluated at ~55%, which allows recording of images with a much better contrast than that with PTA in organic solvents without the PLGA (QY ~0.5% and ~0 emission polarization) or even that with typical fluorescent organic dyes like rhodamines.

Over the last 20 years, there has occurred an increase in the number, scope, and impact of nanomaterials projects. By leveraging the Surface Plasmon Resonance of metallic nanoparticles for labelling, sensing, and treatment, researchers have demonstrated the versatile utility of these nanomaterials in medicine. The literature provides evidence of use of simple, well-known chemistry for nanomaterials synthesis when the focus is new applications of nanomaterials. A case in point, is the synthesis of metallic nanoparticles, whereby HAuCl4, CuCl2, Cu(acac)2, and AgNO3 are typically employed as nanoparticle precursors. Unfortunately, the use of these precursors limits the number of applications available to these materials - particularly for AuNPs in medicine, where the byproducts of nanoparticle synthesis (most often surface-adsorbed reductants, toxic stabilizers, and growth directors) cause nanoparticles to fail clinical trials. Despite the several thousand publications detailing the advancements in nanoparticle therapeutics, as of 2017, there were only 50 FDA-approved nanoparticle formulations. Less than 10 were based on metallic nanoparticles. This is a problem because many of these nanoparticle therapeutics demonstrate potent cell killing ability and labeling of cells. A solution to this problem may be the use of weakly coordinated, monovalent metal complexes, which require only one electron to reduce them to their metallic state. Further, by designing nanoparticle syntheses around these monovalent complexes, we can employ weaker, environmentally friendly stabilizers. This strategy also forgoes the use of exogenous reducing agents, because the monovalent complexes can be reduced and stabilized by one reagent. Herein we investigate the use of Au(Me2S)Cl, [Cu(MeCN)4]BF4, and AgBF4 with green stabilizers to synthesize a variety of nanomaterials. We find that a range of sizes of spherical particles, as well as a range of sizes of gold triangular prisms can be synthesized by using techniques that follow this strategy.

This thesis explores a method to fabricate magnetic membranes with asymmetric distribution of particles and their testing as actuators. Focus of this research is to fabricate thin polymeric sheets and thickness range of 120-125µm, with asymmetric distribution of magnetic nano particles, employing micromagnets during the fabrication. The micromagnets are used to localize the magnetic particles during the curing process at selected locations. The effect of the asymmetric distribution of magnetic particles in the membrane is used for the first time. Magnetite (Fe3O4) is used as the magnetic particles that is embedded into a polymeric membrane made of polydimethylsiloxane (PDMS); the membrane is then tested in terms of deflection observed by using a high-resolution camera. From the perspective of the biomedical application, PDMS is chosen for its excellent biocompatibility and mechanical properties, and Fe3O4 for its non-toxic nature. Since magnetic actuation does not require onboard batteries or other power systems, it is very convenient to use in embedded devices or where the access is made difficult. A comparative study of membranes with asymmetric and randomly distributed particles is carried out in this thesis. The asymmetric distribution of magnetic particles can benefit applications involving localized and targeted treatments and precision medicine.