This doctoral thesis is an effort to understand how lipid phase-separation induced by diacylglycerol analogues in lipid-based nanoparticles affects their in vivo behavior, leading to specific... Show moreThis doctoral thesis is an effort to understand how lipid phase-separation induced by diacylglycerol analogues in lipid-based nanoparticles affects their in vivo behavior, leading to specific nanoparticle-protein communications and selective cell targeting. By studying how lipid composition affects morphology and this in turn affects the nano-bio interface, a comprehensive picture and prediction of nanoparticle behavior and cell selectivity is provided. More specifically, liposomes containing diacylglycerol analogues are found to phase separate and to be able to specifically target subsets of endothelial cells in zebrafish embryos. The mechanism behind this selective targeting is the result of a triglyceride lipase mediated mechanism due to phase separation and lipid composition, and is conserved in higher organisms (mice). Moreover, mRNA-based lipid nanoparticles that contain diacylglycerol analogues exhibit the same selectivity which leads to cell-specific mRNA delivery and transfection. Show less
The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is a promising approach for anti-cancer immunotherapy by bridging innate and adaptive immunity. Recent evidence... Show moreThe cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is a promising approach for anti-cancer immunotherapy by bridging innate and adaptive immunity. Recent evidence suggests that chemotherapy-induced DNA damage can directly induce dendritic cell (DC) maturation and recruitment, which synergizes with STING activation to enhance anti-tumor effects. As an immunogenic cell death (ICD) inducer, oxaliplatin generates massive double-stranded DNA (dsDNA) crosslinks, release of tumor-associated antigens and promoting the "eat me" signal. STING activation improves antigen immunogenicity, which can promote T cell activation and infiltration. In this study, we developed liposomes encapsulating oxaliplatin and combine this formulation with a STING agonist (ADU-S100) for treating colorectal cancer. The liposomes efficiently inhibited the proliferation of tumor cells while induced ICD in CT26 colorectal cancer cells, which enhanced dendritic cell maturation and phagocytosis in vitro. The liposome-based immunochemotherapy exhibited the strongest efficacy, resulting in complete remission upon tumor inoculation. Mechanistic studies showed this potent anti-cancer effect was related to the significant recruitment of infiltrating CD8 and CD4 T cells, reduction of suppressive Treg cells, and a shift in the phenotype of tumor-associated suppressive macrophages that promote cancer to immune stimulating macrophages. Thus, our study demonstrated the potential of combining oxaliplatin-loaded liposomes with a STING agonist to reduce tumor growth by regulating the immunosuppressive state in the tumor. Show less
This thesis aimed to investigate core cross-linked polymeric micelles (CCPMs) and expand their potential for the delivery of hydrophobic drugs and co-factors. Applying polypept(o)ides as the... Show moreThis thesis aimed to investigate core cross-linked polymeric micelles (CCPMs) and expand their potential for the delivery of hydrophobic drugs and co-factors. Applying polypept(o)ides as the polymeric platform technology, the fundamental implications of secondary structure formation on ring-opening N-carboxyanhydride (NCA) polymerization and self-assembly were examined and optimized. CCPMs with functional core architectures serving external or disease-related stimuli were developed. To establish robust CCPM production, overcome drug resistance mechanisms, and explore therapeutic agents for immunomodulation, polymer science was combined with organic and inorganic chemistry. Show less
Tumor heterogeneity favors tumor tissue to survive and resist drugs, leading to the failure of chemotherapeutic agents to induce a therapeutic response. In addition, the absorption mechanisms,... Show moreTumor heterogeneity favors tumor tissue to survive and resist drugs, leading to the failure of chemotherapeutic agents to induce a therapeutic response. In addition, the absorption mechanisms, metabolism and excretion of chemotherapeutic drugs, which are commonly used for cancer patients and the lack of specific targeting of these drugs can cause adverse effects on treated patients. Thus, the general objective of this thesis is to investigate the biological activity of targeted poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) as a drug delivery system (DDS) for carvedilol (CVDL) or oxaliplatin (OXA), in vitro and in vivo, to treat colorectal cancer (CRC). DDSs were formulated to achieve this goal. In chapters 2, 3 and 4, our studies were discussed in detail on the formulations and characterizations of NPs as DDSs with ideal characteristics to increase the therapeutic range of drugs at the tumor site. As well as the biological evaluation of these DDS when its anti-inflammatory activity (Chapter 2) and its antitumor activity in vitro (Chapters 2, 3 and 4) and in vivo (Chapters 3 and 4). Taken together, all the DDSs studied in this thesis were able to improve the chemotherapeutic efficiency of the drugs studied in Chapters 2, 3 and 4. Show less
Dit proefschrift beschrijft een collectie aan alternatieve strategieën voor het begrijpen, ontwerpen en toepassen van lipide nanosystemen, waarin de rol van de bio-nano interacties centraal staan.... Show moreDit proefschrift beschrijft een collectie aan alternatieve strategieën voor het begrijpen, ontwerpen en toepassen van lipide nanosystemen, waarin de rol van de bio-nano interacties centraal staan. In het bijzonder wordt gekeken naar de interactie van RNA-lipide nanosystemen, bekend van de toepassing als vaccins en andere medicatie. Het onderzoeksgebied van de nanomedicatie kan gebruik maken van de specifieke voorbeelden die worden beschreven, maar er kan ook inspiratie worden opgedaan om de aanpak van onderzoek doen te verschuiven van een kostbare empirische aanpak naar rationeel gedreven ontwerpstrategie. Dit alles zal helpen in de ontwikkelen van nieuwe RNA therapieen in de toekomst. Show less
The work described in this dissertation contributes to a better mechanistic understanding of nanoparticles in vivo. To achieve that goal, we used the zebrafish as a highly predictive pre-screening... Show moreThe work described in this dissertation contributes to a better mechanistic understanding of nanoparticles in vivo. To achieve that goal, we used the zebrafish as a highly predictive pre-screening model of nanoparticles. This approach enables the investigation of the fundamental behavior of nanoparticles, correlation of the physicochemical properties of the formulated nanoparticles with their biodistribution and identification of important nano-bio interactions. Zebrafish established transgenic lines were used to study specific interactions. In addition, genetically modified zebrafish applying CRISPR/Cas9 were generated. These strategies not only show key mechanistic features of nanoparticles in circulation, but also promote the rational design of more efficient nanoparticles systems.After understanding the fundamental behavior of nanoparticles, this thesis describes the identification of a key interaction between stabilins receptors (expressed in liver sinusoidal endothelial cells) and nanoparticles. Next, the scope is changed to design nano-systems that target specific cell types showing liposomes capable of switching the surface charge in situ and in vivo using light as an external trigger and a rationally designed lipid nanoparticle formulation containing mRNA able to preferentially target the hepatic reticuloendothelial system. In addition, a phase-separated liposomes hijacking a lipase mediated transport to selectively target endothelial lipase in vivo was studied. Show less
Proteins play a crucial role in life, taking part in all vital process in the body, and are therefore used as therapeutic agents in a diverse range of biomedical applications. When... Show more Proteins play a crucial role in life, taking part in all vital process in the body, and are therefore used as therapeutic agents in a diverse range of biomedical applications. When administrated into bodily fluids, most native proteins are prone to degradation or inactivation process. The challenges of protein delivery are overcoming poor stability, low permeability toward cell membrane. Among all existing materials for protein delivery, mesoporous silica nanoparticles (MSNs) are one of the most promising intracellular nanocarriers due to its key properties: biocompatible, straightforward synthesis, and surface modification. For various biomedical applications, monodisperse MSNs with a particle size in the 50-200 nm range,3 controllable surface chemistry,4 and a large pore size (> 5 nm) are desired. This thesis presents a new method to synthesize large disc-like pore (10 ± 1 nm) containing MSNs with an elongated cuboidal-like geometry (90 × 43 nm), which effectively encapsulate and release proteins. Show less
Kroon, J.; Metselaar, J.M.; Storm, G.; Pluijm, G. van der 2014
