Restoration projects use native plants such as sea oats (Uniola paniculata) to help stabilize the coast. Sea oats are a native grass that can collect blowing sand to build dunes. Sea oats used in the restoration projects can be produced using sexual or asexual techniques. An ideal seedling would be genetically distinct, have increased seed production and germination, and have superior vegetative biomass. Finding ways to produce, propagate, and grow coastal plants such as sea oats effectively is critical to efforts to reduce erosion. In this study, production of sea oats via greenhouse based hydroponic systems was studied. This was accomplished by using fresh, brackish, and saline water conditions and then varying the amount of phosphorus fertilizer. Root growth was shown to be significantly affected by salinity, with an optimal salinity of 10 ppt. Phosphorus fertilizer was not statistically significant. When the mortality was investigated, there was an area of interest with a predicted mortality rate of 80%. The area was between 1.25x and 1.5x concentration of phosphoric acid and 7 and 13 ppt of salinity. The schematics of the hydroponic system, coupled with the findings, should assist growers and researchers in optimal growing conditions under hydroponic greenhouse conditions. Further studies are needed to assess if other nutrient conditions may have significant effects, and how plants grown in a greenhouse may survive in field conditions. Ultimately, this work should contribute to efforts to effectively produce plants, which will help reduce erosion and assist in coastal restoration efforts.

ABSTRACT As life expectancies rise and the average age of our population increases, there has emerged a growing need for joint repair and replacement surgeries due to worn out, torn, or damaged cartilage and bone tissue. This has resulted in an escalating demand for further development of the materials used in joint replacement surgeries and advances in joint repair technology. Researchers in the tissue engineering and regenerative medicine fields have furthered the development of advanced materials for musculoskeletal repair by utilizing growth factors, nanomaterials, and antibiotics within the repair material. The first aim of this thesis was to provide a summary of the current literature on advances in joint repair materials. While there have been many advances utilizing calcium phosphates to aid in bone regeneration; calcium phosphates now just represent a single ingredient within the state-of-the-art complex biomaterials for joint repair. These combination materials can achieve up-regulation of osteogenesis within the wound site. Furthermore, as the advances in nanofabrication have branched to most fields of science and engineering, the development of complex nanocomposites has become a common strategy for resolving difficult multi-tissue repair problems. The development of this class of bioactive, biomaterial nanocomposites is reviewed within todays current literature. The second aim of this thesis was to construct a new biomaterial aiding in joint repair. By utilizing thermally initiated frontal polymerization, a bioactive, degradable bone augment was constructed that would provide orthopedic surgeons a material with an extended working time, good mechanical stability, and potentially osteoconductive and osteoinductive activity. Four ratios of monomers were explored in an effort to optimize the mechanical properties, chemical stability and cytocompatibility. The ratio of 5:1 acrylate monomer to thiol monomer provided the best overall material characteristics: high cytocompatibility, compressive mechanical strength of 3.65 MPa, and a maximum propagation temperature of 160°C +/- 10°C.

Polymeric nanocarriers improve cellular uptake, stability, solubility, and functionality of entrapped drugs and nutraceuticals. The hypothesis of this study was that entrapping lutein, a hydrophobic antioxidant, in different polymeric nanoparticles (NPs) will improve its stability and antioxidant activity. The following objectives were proposed: 1. Synthesize and characterize polymeric nanoparticles of poly lactic co-glycolic acid (PLGA) and PLGA NPs covered with a layer of chitosan (PLGA/Chi) from a physicochemical perspective, and 2. Assess functionality of the entrapped lutein as a function of type of polymer in which entrapped. Nanoparticles were synthesized by emulsion evaporation method. Characterization included size, zeta potential, and morphology measurement, followed by testing the physical and chemical stability, and antioxidant activity of entrapped lutein. PLGA NPs loaded with lutein were in the size range of 119.2 nm ± 0.98 nm with a PDI of 0.17± 0.02 and a zeta potential of 29 mV ± 1.1 mV in nanopure water with 0.05 mg PVA/ mg PLGA ± 0.002 mg PVA/ mg PLGA remaining on the surface of the nanoparticles. PLGA/Chi NPs loaded with lutein were in the size range of 145.9 ± 0.3 nm with a PDI of 0.25 ± 00.01 and a zeta potential of 21.2 mV ± 2.3 mV with 0.06 mg ± 0.002 mg PVA/ mg PLGA/Chi remaining in nanopure water. PLGA NPs and PLGA/Chitosan NPs loaded with lutein were stable in emulsions made with Tween 20 for 72 hours at 37 °C as indicated by a constant size over time. PLGA and PLGA/Chi NPs protected the chemical stability of lutein in Tween 20 emulsions for 24 hours at 37 °C. PLGA and PLGA/Chitosan NPs showed significant reductions in the oxidation of cholesterol by 45 ± 1% and 60 ± 1 % at 48 hours, and 36 ± 1 % and 42 ± 3 % at 72 hours when compared to the free lutein. The addition of chitosan to the PLGA NPs further enhanced the efficacy of lutein as an antioxidant when compared to PLGA NPs. These results support the hypothesis that polymeric NPs are enhancing stability and antioxidant activity of entrapped lutein and hence may find beneficial applications in the biomedical and food science fields for delivery of lutein.

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This project explored a gene-regulated chemotherapy using a silver nanoparticle (SNP) conjugated with deoxyribozyme (DNAzyme) oligonucleotides which target a mutated gene in select cancer cells, sensitize them to doxorubicin treatment. Light exposure to the SNP-DNAzyme conjugates disengages the oligonucleotides and permits specific cleavage of the Kirsten Rat Sarcomal Oncogene Homolog (K-RAS) mRNA. These conjugates could provide spatiotemporal specificity in killing only those photoexposed cells with the mutant gene. Synthesis, functionalization and characterization of citrate and hydroxypropyl cellulose SNP conjugates confirmed attachment and photolytic release of the thiol-modified 10-23 DNAzyme. Gel electrophoresis was used to demonstrate DNAzyme photoactivation, showing greater K-RAS RNA degradation when disengaged compared to the SNP-tethered form. DNAzyme in the tethered form was also protected from DNAse degradation compared to photolyzed DNAzyme. Characterization of the toxicity and localization of the nanoparticle drug delivery system constructed for the release of a photolabile DNA oligonucleotide was checked within several sets of cells to check for temporal and spatial control efficiency. MTS, alamar blue, and flow cytometry assays were performed to assess cell viability in several sets of cell cultures, including HEK293 and MCF-7 (wildtype K-RAS), SW480 and MDA-MB-231 (mutant K-RAS), and 3T3 (negative control) lines. Following the 5-day experimental protocol involving staggered treatment with SNP-DNAzyme, UV light, and doxorubicin, no cell group showed the intended pattern of necrosis in mutant K-RAS cells without morbidity in controls or partial treatments. Thus further evaluation of K-RAS+/- cells which respond consistently in viability assays is necessary before this strategy can be deemed of potential as a targeted therapeutic.

The published benefits of polymeric nanoparticles as a system for antioxidant delivery have encompassed topics of improved oral delivery, bioavailability, and modified release to name a few. Generally accepted as safe polymers Poly(lactic-coglycolic acid) and the mucoadhesive chitosan were selected to entrap alpha-tocopherol and lutein. This study proposed to assess the physical stability of PLGA and Chi/PLGA nanoparticles with entrapped bioactives in varying biological suspension medias ( water, pbs, hbss and cell media). Also, to assess the chemical stability of the entrapped antioxidants lutein and alpha-tocopherol within the same media as deemed relevant for in-vitro and and in-vivo studies. Of the tested media, physical stability was not media dependent for the PLGA(AO) or PLGA/Chi (AO) particles. Neither the size nor the PDI appeared significantly affected by the media it was re-suspended. Entrapped alphatocopherol remained chemically stable throughout the time suspended in the various biological mediums. While the lutein emulsion stability decreased over time, the NP(L)demonstrated improved stability. Also, the entrapped lutein stability was not dependent on the selected medium. Identifying any potential effects of suspension media on polymeric nanoparticles and the entrapped bioactive affords the opportunity to improve analysis of more robust or complex nanoparticle studies. Also, presented are considerations that should be taken prior to design of an experiment.

Nanotechnology has become integrated in commercial, industrial and medical products, and its use has grown exponentially in the past several years. Although potential applications of nanoparticles (NPs) are numerous, concerns about their water quality, environmental, and human health impacts remain unclear. Crayfish are ubiquitous to streams and wetland habitats, are used as a food source, and inhabit areas that could be impacted by water quality issues. Numerous studies have been conducted on the toxicity of various classes of agricultural pesticides and oils to crayfish (Procambarus clarkii) as a non-target organism. However, there is little evidence published on chronic toxicity of NP to crayfish. The first objective of this study was to estimate the 28 day toxicity and bioaccumulation of the three most produced nanoparticles, Ag, ZnO, and TiO2, in a laboratory adult crayfish model. The organisms were exposed to different Ag, ZnO, and TiO2 nanoparticle solutions at concentrations of 0, 100, 500, and 1000 𝜇g/mL. AgNO3 and KNO3, and Zn(NO3)26H2O and KNO3 were used as bulk controls for Ag and ZnO treatments, respectively. Dead crayfish were removed and preserved then examined for metal accumulation and pathological changes in behavior. Metal accumulation in major organs was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Results indicate that as the concentration of NP increases the uptake of metal in tissue also increases. In this case, the chemical rankings of toxicity are as follows: AgNO₃ > Zn(NO₃)₂ > AgNP > ZnO > KNO₃ > TiO₂. Silver accumulated in gill tissue 3 times more in AgNO3 treatments than in AgNP treatments. In abdominal tissue, silver accumulated 4 times more in AgNO3 treatments than in AgNP treatments. Zinc accumulated in gill tissue 2 times more in Zn(NO₃)₂ treatments than in ZnO treatments. The second objective was to estimate the bioaccumulation of the nanoparticles: Ag, ZnO, and TiO2 in a mesocosm adult crayfish model. From previous experiments, we determined the following concentrations for each tank: AgNPs 20 mg/L, ZnO 50 mg/L, and TiO2 100 mg/L. A 0 mg/L control tank was also used. Three crayfish were removed from each tank and preserved for analysis weekly. Soil samples were taken bi-weekly. ICP-OES was used to look at the accumulation of the metals in the gill and abdominal tissues as well as the soil samples. Results indicate that bioaccumulation occurs in tissues in fluctuating trend rather than an increasing trend.

Developing materials that are environmentally friendly and capable of high performance is important to maximize the efficiency and success of coastal restoration projects. Louisiana is losing large amounts of coastal land each year, while suffering 90% of the United States coastal wetland loss. Some areas have begun to implement physical structures to dissipate wave energy and accrete sediment. Recent technological advances have allowed the transformation of these structures into engineered ecosystems, with a focus on oyster accumulation. These ecosystems support the growth of oysters, Crassostrea virginica, which serve to improve water quality and protect shorelines through filtration and wave energy attenuation. An evaluation of scale-model reefs showed bioaccumulation on various cement mixtures, as well as the customization available with the implementation of artificial reefs. This customization also allows the use of bioengineered oyster reefs in the creation of more sustainable coastal homes, with the combination of various architectural techniques, as structural and ecological members. Artificial reefs can be used for protection of the homes and shorelines, while also serving as a valuable food source, not only through oyster growth, but through the attraction of a large number of crab, shrimp and fish, as well. Alternative methods of oyster harvest are also explored in this study. An artificial cultch material showed insignificant differences (p=0.0726) in oyster growth when compared to oyster shell, the typical substrate used in oyster production. The artificial cultch could be used as a viable substitute, in areas where oyster shell is either limited or expensive. This body of work shows the potential for the use of sustainable and ecologically valuable artificial materials in coastal and oyster reef restoration.

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