Browsing by Subject "nanoparticles"
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Item Astrocyte TIMP-1: Regulation and Gene Delivery in HAND(2018-12) Joshi, Chaitanya R.; Ghorpade, Anuja; Clark, Abbot F.; He, Johnny J.; Sumien, Nathalie; Rickards, Caroline A.Despite antiretroviral therapy, HIV-associated neurocognitive disorders (HAND) persist in 30-70% of patients. During HAND, elevated matrix metalloproteinases (MMPs) in the brain exacerbate the disease by blood-brain barrier breakdown, neuroinflammation and direct neurotoxicity. Tissue inhibitors of metalloproteinases (TIMPs) counter MMP activity. In the brain, TIMP-1 is primarily produced by astrocytes in response to injury or inflammation. However, TIMP-1 is downregulated during chronic inflammation in astrocytes and in HIV encephalitis brain tissues. We propose that restoring astrocyte TIMP-1 levels could mitigate neurodegeneration due to its MMP-inhibitory and -independent neuroprotective functions. HIV-1 non-productively infects astrocytes, which express viral proteins such as transactivator of transcription (Tat). As Tat mimics aspects of HAND by direct and indirect mechanisms, glial fibrillary acidic protein (GFAP) promoter-restricted Tat expressing (GT-Tg) mice were used to model HAND in our studies. Prolonged astrocyte Tat expression in GT-Tg mice resulted in HAND-relevant behavioral impairments characterized by higher anxiety, lower ambulation, impaired spatial learning, and memory. Importantly, behavioral deficits were accompanied by altered brain MMP/TIMP balance. Our data from GT-Tg mouse model confirmed neurocognitive decline and TIMP-1 dysregulation in the context of HAND. As TIMP-1 was downregulated with prolonged Tat expression in mice, we focused on replenishing TIMP-1 via gene delivery to the brain using cationic polymers. Polyethylenimine (PEI) is a highly efficient polymer for transfecting mammalian cells, however, high cytotoxicity restricts its use. Hence, PEI was modified using arginine (A) and stabilized with polyethylene glycol (P) to produce multiple AnPn analogues. AnPn analogues were biocompatible and successfully delivered reporter genes to primary neural cells. Select AnPn led to sustained reporter gene expression in human astrocytes and in mouse brains. In order to restrict gene expression to astrocytes, truncated GFAP promoters were used to drive gene expression. Subsequently, GFAP promoters were modified enhancing their activity and increasing gene expression. Lastly, successful polymer-mediated GFAP promoter-driven TIMP-1 gene delivery was demonstrated in human astrocytes. Overall, these findings enhance our understanding HIV-1 Tat-mediated TIMP-1 regulation, provide a novel therapeutic TIMP-1 gene delivery system, and pave the way for future investigations geared towards preclinical translation of TIMP-1-based HAND therapy.Item Bioengineered Nanoparticles for Targeted Cancer Therapy(2018-05) Gdowski, Andrew S.; Vishwanatha, Jamboor K.; Ranjan, Amalendu P.; Cistola, David P.; Olivencia-Yurvati, Albert H.Despite improved overall survival in cancer patients over the past 50 years, limited advances have been made in treating patients with metastatic cancers. Multiple types of cancers demonstrate the unique ability to specifically metastasize to the bone. Among these, prostate cancer exhibits increased capacity to create bone specific lesions with high frequency. Once bone localization takes place, treatment regimens are limited and overall survival is poor. These bone metastases often cause debilitating and life threatening problems including: uncontrollable pain, hypercalcemia, broken bones, spinal cord compression, and the inability to perform activities of daily living. The overarching goal of this thesis was to develop novel bone targeted nanoparticle therapies. The first generation of nanoparticles we engineered and tested were designed to target the hydroxyapatite structure of the bone particularly in areas of high bone turnover with subsequent therapeutic release at the site of the tumor. Notably, this nanoparticle formulation was efficacious in decreasing prostate cancer bone metastatic tumors, improving bone structure, and reducing pain in a mouse model. The next generation of nanoparticles were developed to simultaneously target the bone endothelium and tumor cells using a programmable bioinspired approach with guidance from genomic information of prostate cancer patients. This novel bioinspired nanoparticle demonstrated enhanced ability to self-recognize cancer cells as well as improved bone homing and retention in our in vivo evaluation. Finally, we addressed the challenge of nanoparticle manufacturing scale up from lab size quantities to large scale batches using a microfluidic process. It is our sincere hope that concepts and publications derived from this thesis will help guide future efforts for targeted therapy and improve the lives of patients with cancer.Item Characterization and Optimization of Nanoparticles for Polynucleotide delivery(2015-05-01) Conjeevaram Nagarajan, Bhavani Saranya; Lacko, Andras G.; Cistola, David P.; Krishnamoorthy, Raghu R.Nucleic acid therapeutics involves the use of polynucleotides (DNA, RNA) as novel therapeutic agents for the treatment of a wide range of diseases including cancer and several metabolic and genetic disorders. However, the highly unstable nature of RNA molecules necessitates the use of drug carriers to prevent them from nuclease degradation and facilitate targeted delivery in vivo. Hence, this study was conducted to optimize the preparation of nanoparticle carriers in order to improve the stability of the polynucleotides (siRNA and mRNA). Additionally, as heterogeneity and stability of nanoparticle formulations are major issues preventing the clinical approval of therapeutic formulations this study was also focused on improving the homogeneity and the stability of the nanoparticles. In the siRNA study, reconstituted high density lipoprotein (rHDL) nanoparticles were used as the delivery vector. Optimization of siRNA-rHDL formulation was attempted with respect to homogeneity, size of the nanoparticle and entrapment efficiency of siRNA. The results showed that the inclusion of the lyophilization step in the preparation of nanoparticles resulted in a marginal increase in the homogeneity. The size analysis of siRNA rHDL nanoparticles using AFM and TEM imaging revealed the presence of spherical nanoparticles in the range of 10-16nm. Optimization studies with mRNA peptide nanoparticle formulation were conducted using a combination of cationic detergents and peptides at varied concentrations. The particle size analysis via Dynamic Light Scattering (DLS) detector revealed the presence of 268 nm diameter particles as the major component of the mRNA nanoparticle formulation that involved the combination of DOTAP (neutralizer) and Myr-5A (Apo A-I mimetic peptide). Further optimization of this formulation will be required to improve the homogeneity of the nanoparticles.Item Development and In Vitro Characterization of Gemcitabine Loaded Nanoparticles for Pancreatic Cancer Therapy(2021-05) Pham, Jennifer H.; Ranjan, Amalendu P.; Fudala, Rafal; Mathew, Stephen O.Pancreatic Ductal Adenocarcinoma (PDAC) is the 4th leading cause of cancer deaths worldwide and the most common type of pancreatic malignancy (90%). With a poor five-year survival rate of only 5-8%, complete surgical resection remains the only curative treatment. However, most patients are diagnosed at a later stage where chemotherapy and radiotherapy are the only options. Gemcitabine is the FDA-approved treatment for PDAC, but the current therapy leads to more severe side effects due to the instability of gemcitabine in the blood stream and its poor membrane permeability. Nanoparticles are effective in cancer therapy because they allow modifications that make for a more effective delivery method and also reduces the toxicity to normal tissue. In this proposed study, we aim to formulate, optimize and evaluate the in vitro effectiveness of gemcitabine loaded nanoparticles in a PDAC cell line in order to improve the effectiveness of current chemotherapy treatments for pancreatic ductal adenocarcinoma. We found out of the three types of nanoplatforms used for encapsulating gemcitabine (GEM-NPs): polymeric, liposomal and lipid polymer hybrid, the liposomal nanoparticles were the most effective in the encapsulation of gemcitabine according to the physicochemical properties, such as average particle size, zeta potential, drug loading and encapsulation efficiency. In vitro functional evaluation of liposomal formulation was done in a PDAC cell line (PANC-1). This study suggests that the use of liposomal nanoparticles is the most beneficial in the encapsulation and delivery of gemcitabine.Item Development of In Situ Self-Assembly Nanoparticles to Encapsulate Lopinavir and Ritonavir for Long-Acting Subcutaneous Injection(MDPI, 2021-06-18) Tanaudommongkon, Irin; Tanaudommongkon, Asama; Dong, XiaoweiMost antiretroviral medications for human immunodeficiency virus treatment and prevention require high levels of patient adherence, such that medications need to be administered daily without missing doses. Here, a long-acting subcutaneous injection of lopinavir (LPV) in combination with ritonavir (RTV) using in situ self-assembly nanoparticles (ISNPs) was developed to potentially overcome adherence barriers. The ISNP approach can improve the pharmacokinetic profiles of the drugs. The ISNPs were characterized in terms of particle size, drug entrapment efficiency, drug loading, in vitro release study, and in vivo pharmacokinetic study. LPV/RTV ISNPs were 167.8 nm in size, with a polydispersity index of less than 0.35. The entrapment efficiency was over 98% for both LPV and RTV, with drug loadings of 25% LPV and 6.3% RTV. A slow release rate of LPV was observed at about 20% on day 5, followed by a sustained release beyond 14 days. RTV released faster than LPV in the first 5 days and slower than LPV thereafter. LPV trough concentration remained above 160 ng/mL and RTV trough concentration was above 50 ng/mL after 6 days with one subcutaneous injection. Overall, the ISNP-based LPV/RTV injection showed sustained release profiles in both in vitro and in vivo studies.Item Effect of Composition and Size on Surface Properties of Anti-Cancer Nanoparticles(MDPI, 2023-09-09) Mishra, Ina; Garrett, Meredith; Curry, Stephen; Jameson, Jeffrey; Kastellorizios, MichailLiposomal formulations offer significant advantages as anticancer drug carriers for targeted drug delivery; however, due to their complexity, clinical translation has been challenging. In addition, liposomal product manufacturing has been interrupted in the past, as was the case for Doxil((R)) (doxorubicin hydrochloride liposome injection). Here, interfacial tension (IFT) measurements were investigated as a potential physicochemical characterization tool to aid in liposomal product characterization during development and manufacturing. A pendant drop method using an optical tensiometer was used to measure the interfacial tension of various analogues of Doxil((R)) liposomal suspensions in air and in dodecane. The effect of liposome concentration, formulation (PEG and cholesterol content), presence of encapsulated drug, as well as average particle size was analyzed. It was observed that Doxil((R)) analog liposomes demonstrate surfactant-like behavior with a sigmoidal-shape interfacial tension vs. concentration curve. This behavior was heavily dependent on PEG content, with a complete loss of surfactant-like behavior when PEG was removed from the formulation. In addition to interfacial tension, three data analyses were identified as able to distinguish between formulations with variations in PEG, cholesterol, and particle size: (i) polar and non-polar contribution to interfacial tension, (ii) liposomal concentration at which the polar and non-polar components were equal, and (iii) rate of interfacial tension decay after droplet formation, which is indicative of how quickly liposomes migrate from the bulk of the solution to the surface. We demonstrate for the first time that interfacial tension can be used to detect certain liposomal formulation changes, such as PEG content, encapsulated drug presence, and size variability, and may make a useful addition to physicochemical characterization during development and manufacturing of liposomal products.Item Nasal Tumor Vaccination Protects against Lung Tumor Development by Induction of Resident Effector and Memory Anti-Tumor Immune Responses(MDPI, 2023-02-26) Donkor, Michael; Choe, Jamie Y.; Reid, Danielle; Quinn, Byron; Pulse, Mark; Ranjan, Amalendu P.; Chaudhary, Pankaj; Jones, Harlan P.Lung metastasis is a leading cause of cancer-related deaths. Here, we show that intranasal delivery of our engineered CpG-coated tumor antigen (Tag)-encapsulated nanoparticles (NPs)-nasal nano-vaccine-significantly reduced lung colonization by intravenous challenge of an extra-pulmonary tumor. Protection against tumor-cell lung colonization was linked to the induction of localized mucosal-associated effector and resident memory T cells as well as increased bronchiolar alveolar lavage-fluid IgA and serum IgG antibody responses. The nasal nano-vaccine-induced T-cell-mediated antitumor mucosal immune response was shown to increase tumor-specific production of IFN-gamma and granzyme B by lung-derived CD8(+) T cells. These findings demonstrate that our engineered nasal nano-vaccine has the potential to be used as a prophylactic approach prior to the seeding of tumors in the lungs, and thereby prevent overt lung metastases from existing extra pulmonary tumors.Item North Texas Health & Science - 2011, Issue 2(University of North Texas Health Science Center at Fort Worth, 2011-01-01)Item Optimization of Reconstituted High Density Lipoprotein nanoparticles as a Delivery System for Neuroblastoma(2013-12-01) Hinze, Cheryl L.; Lacko, Andras G.Despite many advances in cancer therapy over the last few decades, cancer remains one of the most common causes of death in not only the United States, but around the world. Two of the major problems cancer patients face today are the horrific side effects associated with chemotherapy, and the development of drug resistance. Both of these become even bigger problems when they are applied to children. Neuroblastoma is one of the most common forms of pediatric cancer. High risk Neuroblastoma patients are commonly faced with intensive multi-modal therapies in attempt to overcome a very aggressive disease. Due to the intensive therapy required, side effects can often linger even after remission is achieved in these patients, and multi-drug resistance is common due to the high levels of Doxorubicin administered. New solutions are needed in order to overcome both of these problems in Neuroblastoma as well as other types of cancer. In this thesis, we studied the effects of different formulation and preparation techniques for the reconstituted high density lipoprotein nanoparticle model for anti-cancer agent delivery. During these studies we found that naturally derived mixes of phosphatidylcholine, and lower levels of apolipoprotein A-1 increase the encapsulation efficiency of the rHDL nanoparticles. We also determined that the addition of lyophilization during preparation before cholate dialysis, forms a more homogeneous preparation. After the optimization of the particle formulation and preparation, we tested the efficacy of two model anti-cancer agents in different cancer cells. First we showed the ability of the rHDL-siRNA nanoparticles to knockdown the SR-B1 protein is greater than the knockdown of a commercial transfection kit. Finally we prove that the rHDL also improves the cytotoxic efficacy of a novel treatment for Neuroblastoma involving Imatinib Mesylate and Saquinavir. In conclusion, the results of this thesis show a more detailed knowledge of the rHDL nanoparticle formulation as well as how it can be applied as an effective delivery system for both siRNA and chemotherapeutic agents. This data should help push our formulations closer to clinical applications, and toward helping reduce the toxic side effects of many chemotherapeutic agents, as well as reducing the incidence of drug resistance.Item Targeted Delivery of [alpha]-Mangostin to Prostate Cancer Cells Utilizing Reconstituted High-Density Lipoprotein Nanoparticles(2022-08) Kapic, Ammar; Berg, Rance E.; Basha, Riyaz; Ranjan, Amalendu P.Item TARGETED DELIVERY OF A NOVEL COMBINATION THERAPY FOR NEUROBLASTOMA(2013-04-12) Hinze, CherylPurpose: Neuroblastoma (NB) is the most common solid extra-cranial tumor found in children. The prognosis for late stage or high risk Neuroblastoma patients remains very low despite very intense multi-modal therapies. The patients that do survive, and reach remission from aggressive NB have a much increased risk of developing cancer again later in life. Therefore it is important to increase the efficacy of the current treatments, while decreasing their toxic side effects in order to raise these patients' standard of living. One of the novel therapies currently being explored for NB is a combination of the chemotherapeutic agent Imatinib Mesylate (Imatinib), a tyrosine kinase inhibitor specific for c-kit and platelet derived growth factor receptor, both of which are expressed on NB cells, and Saquinavir, a protease inhibitor with anti-cancer properties, that is currently used in anti-HIV therapy. Previous studies have shown Saquinavir to be effective against Chronic Myeloid Leukemia cells; therefore we anticipate that it might also be effective against NB cells and tumors. We propose that the encapsulation of this combination of drugs into our reconstituted high density lipoprotein (rHDL) system will not only improve their therapeutic action against NB, but will also reduce their off target toxicity, via amount of toxic side effects due to the selective delivery properties of the rHDL Nanoparticles. Methods: The rHDL particles were prepared using the cholate dialysis method. The particles were then characterized for their physical properties and chemical composition. Size of the particles was determined using dynamic light scattering. SJ-N-KP and SMS-KCNR cells were plated in 96 well plates at a concentration of 5 x 103 cells per well. The Dojindo CCK8 test was used to measure cytotoxicity for both free and encapsulated Imatinib and Saquinavir after 48 hour exposure to the drugs. Results: The mean diameter of the Imatinib-rHDL particles was found to be 97.1 nm, and the mean diameter of the Saquinavir-rHDL particles was found to be 33.1 nm. Encapsulation of the Saquinavir into rHDL nanoparticles has shown up to a 100 fold increase in cytotoxicity in NB cell lines. Conclusions: Our studies show that encapsulation of this novel drug combination into rHDL nanoparticles greatly increases their efficacy against NB cell lines, thus indicating the potential of this system in combination to improve therapy, and raise the prognosis of NB patients.Item Targeted Nanoparticles for the Treatment of Neuroblastoma(2011-05-01) Pratap, Suraj; Lacko, Andras G.Neuroblastoma (NB) is one of the most frequently diagnosed tumors in infants and children. However, the mechanism by which it is initiated and subsequently develops on the molecular and cellular level is yet to be fully elucidated. Its wide spectrum of clinical presentation has baffled physicians and biomedical scientists alike. The variant called high risk neuroblastoma (HRNB) is extremely resistant to the currently available drug regimes. Despite the recent advances in anti-cancer agents and the use of multi-modality therapy for the treatment of HRNB the morbidity and mortality in this group of patients continues to remain high. The purpose of our project was to find novel alternative therapeutic approaches by encapsulating known anti-NB agents in a lipoprotein based formulation to achieve selected, targeted delivery of these drugs to HRNB tumors. We wanted to enhance the therapeutic efficacy of these drugs that have shown encouraging results in pre-clinical trials but have so far exhibited an adverse pharmacokinetic profile precluding their systemic application. Our laboratory has been working for the last several years on a novel drug delivery platform by encapsulating drugs into the core of high density lipoprotein (HDL) type nano-particles. Using this strategy, we encapsulated all-trans retinoic acid (ATRA), fenretinide (FR) and valrubicin into reconstituted HDL (rHDL) nanoparticles and subsequently evaluated some of their physical and chemical properties and their anti-NB potential. Further, we tested the efficiency of an apolipoprotein mimetic peptide called 5-A peptide as a component of rHDL particles and compared its efficiency with apolipoprotein A-1 (Apo-A1). The 5-A peptide offers numerous advantages over the Apo-A-1 both in terms of cost of production as well as manufacturing time. After successfully encapsulating the drugs, we characterized them and tested their cytotoxic potential on various cancerous cell lines. We also conducted cell uptake studies to test our hypothesis of tissue targeting and selective uptake of rHDL nano-particles mediated by the scavenger receptor type B1 (SR-B1). We conducted a pilot study on nude mice in which we administered rHDL containing fluorescent dye intravenously in mice xenografted with NB tumors and took subsequent images to track its distribution in the body. Our results demonstrate that it is possible to encapsulate ATRA, FR and valrubicin into rHDL preparations with a predictable efficiency; these nano-particles show a dose dependent cytotoxic effect on NB cell lines. We anticipate that the results of our studies will facilitate the application of liposomal nano-particles and these novel drugs in the treatment of HRNB in the future.Item The Neuroprotective Efficacy of Antioxidants Against In Vitro Models of Oxidative Stress and Their Theoretical Application Via Intravitreal Injection Encapsulated in Nanoparticles(2010-05-01) Ondricek, Amber J.; Jamboor VishwanathaThe purpose of this study was to explore the possibility of utilizing antioxidants to mitigate oxidative stress induced apoptosis related to neurodegenerative diseases such as glaucoma. Our hypothesis is that in diseases related to an imbalanced redox status, whatever the primary cause may be, the loss of function may be prevented by antioxidants at the level of alleviating oxidative burden and preventing apoptotic signaling events. Application of these antioxidants to the site of injury can be improved using nanoparticle delivery methods. We have done work to characterize a model of mitochondrial associated oxidative stress induced cell death and obtained neuroprotective profiles on a group of antioxidants using this model. We have found that estrogens and phytoestrogens, as well as thiol containing antioxidants, function well as neuroprotectants in our in vitro model. Nanoparticle delivery of these models is a promising intervention and we therefore did work to optimize the characteristics of encapsulating one of these antioxidants, N-acetyl cysteine, in Poly(lactic-coglycolic acid) nanoparticles, which can be localized to the retina. Intravitreal injection of these particles is the preferred delivery route to retinal cells and has not been fully explored. We provide evidence to suggest that the intravitreal injection of nanoparticles is not detrimental to an animal’s vision. Taken together, the results of our experiments suggest that antioxidants remain a promising intervention in diseases related to mitochondrial associated oxidative stress, and that these drugs, when encapsulated in nanoparticles, can be delivered to the retina via intravitreal injection without deleterious side effects.Item Therapeutic Approaches in the Combat of Pneumococcal Infection(2017-05) Burnley, Brittney N.; Jones, Harlan P.; Su, Dong-MingPneumonia cause by Streptococcus pneumoniae (S. pneumoniae) is prominent in the young and elderly. Our focus is improving prevention and controlling inflammatory responses during S. pneumoniae infection. Using a mouse model, studies tested the efficacy of nasal administration of a nanoparticle-based (NP) vaccine formulation to improve protection against S. pneumoniae. Studies also sought to determine the effect of nasal administration of corticotropin releasing hormone (CRH). Results demonstrated that CRH administration decreased mortality compared to Dexamethasone. CRH's effect was associated with significant decrease in inflammatory responses and its protective effect was observed in the absence of neutrophils. A NP based vaccine decreased bacterial growth in lungs correlating with increased IFNγ production. This research suggests efficacious applications of prevention and treatment of pneumococcal disease.