Research Projects

 

Purification and Characterization of Therapeutic Nanoparticles

Mentor: Dr. Yiming Liu

Therapeutic nanoparticles are emerging as a new class of medicine. They are designed to navigate the therapeutic complex in vivo to achieve target specificity, controlled drug release and pharmacological kinetics. Purification and chemical characterization play critical roles in the safety and their drug properties such as solubility, metabolism, plasma binding, biodistribution, target tissue accumulation. Our research will be focused on the development of effective protocols for fast purification and sensitive bioassay of therapeutic nanoparticles. Based on the physicochemical properties of the nanomedicine targeted, separation techniques, including dialysis, ultrafiltration, electrophoresis, and gel filtration will be investigated to obtain purified products. Bioassay of the final products will be developed by using instrumental methods based on HPLC-MS, CE-MS, and ICP-MS.   

 

 Fate of Phosphorus in the Wetlands of the Northern Gulf of Mexico

Mentor: Dr. Fengxiang Han

Eutrophication is a serious nutrient pollution in the water body. The Gulf of Mexico continues in increasing its hypoxic area annually due to carrying of nutrients N and P through Mississippi River. Moreover, in 2005, a local fertilizer company accidentally released 17.5 million gallons of waste water containing phosphorus (P) from retaining ponds into the Grand Bay National Reserve, resulting in approximately 8 hectares of tidal marsh and 77 hectares of upland devastation. However, after 10 years of the accident, it is essential to re-assess the environmental fate of P in the area and its long-term effects on the biogeochemistry of trace elements and heavy metals of the reserve. The proposed study will provide a solid scientific understanding of the biogeochemical processes controlling P fate in the region. The objectives of this study are to investigate P speciation and its bound in inorganic and organic compounds with NMR and inductively coupled plasma optic emission spectroscopy (ICP-AES).

 

Theoretical Studies on Functionalized Graphene-metal Cluster Interactions

Mentor: Dr. Jerzy Leszczynski

Functionalized graphene – metal nano-cage hybrid platforms are used in recent years for trace level identification of explosives and environment contaminating materials using Raman fingerprints. In the present project, nature of interactions of functionalized graphene systems with model metal (Au and Ag) clusters would be investigated using state of the art density functional theories (DFT). The characterization of such model systems would be based on the simulated Raman spectra. The computed results would be compared with the available experiment/s to justify the validity of such model in silico investigations to explain the interaction characteristics of the related more complex nano systems.

 

Molecular Sensors for Environmentally Important Anions

Mentor: Dr. Alamgir Hossian

Selective recognition of anions has received a tremendous attention in recent years because of their significant importance in biology and environment. Developing application-based anion sensors is a challenging task because of the synthetic difficulties of efficient hosts for anions. Although, several classes of synthetic receptors have been known showing affinity for anions, synthetic receptors for selective anion sensing are still limited in the literatures. This summer project will involve the synthesis of simple tripodal amine-based receptors which are expected to be soluble in water. Because of the presence of amine groups, the neutral compounds are potential to form complexes with transition metal ions. The synthesized receptors will be complexed with Cu(II) ions in order to obtain metal based-hosts. The chain length of the receptors will be varied to observe the effect of cavity sizes. Both free amines and their metal complexes will be investigated for different types of environmentally important anions in water. Targeted anions include fluoride, chloride, bromide, iodide, sulfate, phosphate, nitrate and perchlorate. The molecules will be synthesized using conventional synthetic protocols, and characterized by NMR, mass and elemental analysis. The new compounds will be investigated for a variety of anions in solutions by UV-Vis and fluorescence titrations. The synthesized molecules will also be studied for visual colorimetric detection of certain anions in solution. 

 

Magnetically enriched SERS-Based Hybrid Nanostructure for Multiplex Detection and Quantification of Pathogens.

Mentor: Dr. Ashton Hamme

Bioterrorist threats, ever increasing global demand for fresh water due to population growth, and increased stresses on our freshwater resources due to global climate change aggravate the need for better drinking water pathogen monitoring. To address these concerns, we want to develop a multi-step approach based on magnetically enriched Raman tagged-gold nanopopcorns attached Single-walled carbon nanotube (AuNP@SWCNT) hybrid nanostructures for simultaneous detection and quantification of multiplex waterborne pathogens. Surface enhanced Raman spectroscopy (SERS) will be used to detect two key pathogens: E. coli Migula and Salmonella DT104, via a homogenous sandwich immunoassay detection strategy. Biosensor speci´Čücity and sandwich formation will be integrated through the use of recognition biomolecules that recognize specific epitopes on the exterior of the pathogen. The magnetic NP are well suited for rapid target capturing, enrichment and concentration of the Raman tagged plasmonic hybrid nanostructures within a small region hence will facilitate the formation of hotspots prior to SERS analysis. Thus, it is possible to obtain more reproducible and sensitive signals. Here, SERS tagged multi-branched AuNP@SWCNT will show strong probe signal enhancement because of both electromagnetic and chemical effects. The detectable quantifiable signals will derive from the labeled signal tags as a consequence of immunocomplex formation.

 

Aptamer-Conjugated Theranostic Hybrid Graphene Oxide with Label-Free Biosensing and Combined Therapy Capability

Mentor: Dr. Paresh Ray

Cancer is one of the life-threatening diseases is rapidly becoming a global pandemic. Circulating tumor cells (CTC) detection can predict survival possibility in patients with various metastatic cancers. Driven by the need, we want to development of AGE-aptamer conjugated theranostic magnetic nanoparticle attached hybrid graphene oxide for the ultra-sensitive and label-free detection of tumor cell from infected blood sample.  To enhance anticancer efficiency with minimum side effects, combination therapy is envisioned for malignant melanoma. Our aim is to develop methylene blue (MB) bound AGE-aptamer attached hybrid graphene oxide, which is capable of combined synergistic photo thermal & photodynamic treatment of cancer.

 

Development Ant Testing Sensors Based On Nano0applications

Mentor: Danuta Leszczynska

Electrochemistry is the study of relationship between electricity and chemical reaction. It mainly deals with the loss of electrons (oxidation) or gain of electrons (reduction) at the interface of an electron conductor (the electrode: a metal or a semiconductor) and an ionic conductor (the electrolyte). These reduction and oxidation reactions are commonly known as redox reactions. It gives information about the concentration, kinetics and reaction mechanisms of a species in solution. Electrochemistry is an interdisciplinary science that is mainly rooted in chemistry and physics, and also linked to engineering, biochemistry and biology. Consequently, it has diverse applications in various working fields such as: analytical, environmental, surface, solid state and photo-electrochemistry. Electrochemistry involves the measurement of potential (potentiometry) or current response (voltammetry). Cyclic voltammetry is the most popular electrochemical method. In this method, the current response of a small stationary electrode in an unstirred solution is excited by a triangular voltage waveform. Here we will discuss the cyclic voltammetry in Fe(CN)63-/4- redox system.

 

Examination of elimination rate and pathway of PbSe quantum dotsfrom exposed animals

Mentor: Dr. Zikri Arslan

Semiconductor PbSe nanoparticles are a class nanoparticles, known as quantum dots. These nanoparticles exhibit strong absorption in infrared (IR) to near-IR range, and thus are attractive materials for photovoltaic applications and solar energy conversion. However, these nanoparticles also possess numerous questions about safety or toxicity to environmental and human health. Often PbSe nanoparticles are encapsulated with silica to protect the reactive and unstable core. Thought silica encapsulation could minimize the toxic effects, exposure to these nanoparticles will be inevitable in the future as devices containing these nanocrystals find their way to human daily life. It is therefore important to understand the accumulation and elimination of these nanoparticles from biological system. The goal of this study to investigate the elimination rate and pathway of PbSe nanoparticles from exposed animals. The REU students will be working on the analysis of fecal and urine samples collected from mice exposed in vivo to the nanoparticles. Student will be trained on sample preparation, dissolution and digestions via microwave assisted systems with acids. Alkaline digestion will be also performed to understand soluble fraction of nanoparticles to determine metabolic stability of the particles within the body. The student will be trained on use of ICP-MS and similar analytical instrumentation toward biological analysis. The result from this project will provide insight about bioaccumulation, elimination and possible degradation of the PbSe nanocrystals in live organisms.

 

Bio-inspired Carbon Quantum Dots to study host-pathogen interactions

Mentor: Dr. Ifedayo Ogungbe

The summer research project will involve the design of a robust and multifunctional bio-inspired carbon quantum dots (CQDs)-based fluorescence resonance energy transfer (FRET) probe for detecting and imaging host-pathogen interaction, and to study pathogen clearance in vivo.   The project will involve synthesis and characterization of the CQDs, conjugation with biomolecules, studying their optical properties in live cells and animals, and interrogating host-pathogen interactions.

 

Synthesis and characterization of biodegradable melanin-like nanoparticles for potential imaging guided cancer therapy

Mentor: Dr. Yongfeng Zhao

Magnetic resonance imaging (MRI) is one of the most powerful, non-invasive diagnostic imaging modality in medicine and biomedical research. Photothermal therapy is a new noninvasive treatment technique, which employs light absorbers to convert light energy into heat. The integration of imaging and therapy, that is imaging guided therapy, provide substantial benefit for treatment of disease such as cancer. Imaging component can evaluate disease before therapy, and monitor the prognosis of the treatment. Through the imaging, therapeutical strategies will be optimized. The toxicity of the therapy will be further reduced. Currently, it is still challenging to develop a biocompatible nanoplatform with multifunctional properties of MRI and photothermal effect. In this study, poly(3,4-dihydroxyphenylalanine) nanoparticles with different size will be synthesized. The surface of nanoparticles will be modified to improve the colloidal stability in media. After chelated with iron (II) ions, poly(3,4-dihydroxyphenylalanine) nanoparticles will be studied for the size effect on the MRI imaging and photothermal therapy.