Current Research Projects

“Toxicity of components used in cannabis vaping”

• Cannabis vaping is becoming more widespread, but the potential toxic effects of various ingredients commonly used in vape liquids are not well understood

• This project is especially interested in terpenes (used as flavoring agents) and diluents (used to assist the aerosolization of the flavors and active ingredients), as well as potential synergistic effects between multiple components

Investigator(s): Yanira Baldovinos, Jake Dickinson, James Liu

Collaborator(s): Professor Robert Strongin; Portland State University

“Aerosol exposure surfactometer”

• Lung surfactant exists in the alveolar space and is important to healthy lung function, and there is growing evidence that aerosol contaminants may harm lung function by interfering with lung surfactant properties

• This project aims to develop a novel equipment setup for studying the co-exposure of lung surfactant and lung cells to aerosols

Investigator(s): James Liu

Collaborator(s): Dr. Saber Hussain; Air Force Research Laboratory

“Nanotherapeutics for Huanglongbing disease management in citrus plants”

• Huanglongbing (HLB) is the most devastating disease in the citrus tree, caused by Candidatus Liberibacter asiaticus and transmitted by Diaphorina citri

• HLB management is difficult due to the nonspecific symptoms, late diagnosis, fastidious nature of the bacterium, and irregular distribution of the pathogen in trees

• This project aims to develop novel antimicrobial encapsulated nanoparticles that enter the plant vascular system (phloem) where bacteria reside

Investigator(s): Dr. Swarna Shikha, Katiana Battiste

Collaborator(s): Dr. W. Evan Braswell; Animal and Plant Health Inspection Service, USDA

“Sensitization vs. irritation”

• In an effort to quickly assess potential hazards associated with environmental contaminants in the air, as well as to decrease the use of animals used in safety testing, investigations that lead to verifiable in vitro testing methods are needed

• Sensitization is an irreversible effect initiated and induced by the immune system; we study the exposures to pulmonary sensitizers, cellular activators, and irritating particles

• Results show that compared to naïve cultures, markers for dendritic cell trafficking and antigen presentation are observed as well as increased number and length of dendritic protrusions

Investigator(s): Matthew Gibb

Collaborator(s): Dr. Madhuri Singal, PhD, RRT, DABT; AeroTox Consulting Services, LLC

“Gut tri-culture project”

• There is momentum in biomedical research to improve the structure and function of in vitro intestinal models that better represent human biology; to build a more comprehensive model, three human cell-types are co-cultured and characterized

• The model demonstrates a potentiating effect in metabolism and pro-inflammatory markers and barrier integrity and cell seeding density seem to play a role in the reliability of endpoint readouts

• The data show that monocultures do not have the same characteristics inherent to triple cell culture models; multiple cell types in an in vitro model produce a better representation of an intact organ and aid in the ability to assess immunomodulatory effects of nanomaterials designed for cancer theranostics after ingestion.

Investigator(s): Matthew Gibb and Sahar Pradhan

Collaborator(s): Dr. Jo Anne Shatkin, PhD; Vireo Advisors, LLC

“Nano-neuro-toxicology”

• In vivo and in vitro models can be used to elucidate mechanisms for Parkinson’s disease with neurotoxins in an effort to mimic biochemical inductions related to the disease

• We use an in vitro approach that offers clues in neural cellular communication for Parkinson’s disease

• Viability, metabolic activity, and gene expression are measured pre- and post-treatment; fluorescence and electron microscopy aid in the assessment of mitochondrial health

Investigator(s): Sahar Pradhan

Collaborator(s): Professor Elisabeth G. Vichaya, PhD; Baylor University

"Changes in mitochondrial health after nanomaterial exposure: A useful biomarker in toxicology research"

• We aim to use the mitochondria as a non-invasive biosensor for exposure to a variety of engineered nanomaterials

• We measured reactive oxygen species (ROS) generation and cellular viability in mammalian cells following exposure to aluminum nanoparticles

• We found a dose-response change in coupling efficiency between ATP production and oxidative phosphorylation, which can be an early indicator for the onset of metabolic disease

• Further research has the potential to reveal mechanisms of toxic action related to low dose exposures of many different environmental contaminants

Investigator(s): Matthew Gibb and Sahar Pradhan

Collaborator(s): Dr. Saber Hussain, PhD, ATS; U.S. Air Force Research Laboratory

"Comprehensive physicochemical characterization of cellulose materials”

The major objective of this work is to provide qualitative and quantitative characterization of cellulose materials to aid in the advancement of safer renewable resources.

• Ong KJ, Shatkin JA*, Ede J, Mulenos MR, Sayes CM. (2019). “90-day dietary study with fibrillated cellulose in Sprague-Dawley rats”. Food and Chemical Toxicology (accepted).

• Mulenos MR, Zechmann B, and Sayes CM*. (2019). “Sample preparation utilizing sputter coating increases contrast of cellulose nanocrystals in the transmission electron microscope”. Microscopy 68(6):471–474. 

• Ameh T and Sayes CM*. (2019). “Utilizing atomic force microscopy for characterizing cellulose materials”. Texas Journal of Microscopy 50(1):15. 

• Mulenos MR and Sayes CM*. (2018). “Elucidating morphological characteristics of cellulose materials”. Texas Journal of Microscopy, 49(1):19. http://www.texasmicroscopy.org/Journal/49-1Journal.pdf

Investigator(s): Sahar Pradhan and Matthew Gibb

Collaborators: Dr. Jo Anne Shatkin, PhD; Vireo Advisors, LLC

"Synthesis and characterization of nanometer-sized liposomes for encapsulation and micro-RNA transfer to breast cancer cells”

• Liposomes are self-assembled colloidal particles made of phospholipids

• Their increasing use as drug carriers warrants more stringent standards for formulation, preparation, safety, and efficacy

• We aim to define critical quality attributes (CQA) along the pathway of pharmaceutical production

• We synthesized liposomes loaded with microRNA and studied cancer treatment in vitro

Investigator(s): Sahar Pradhan

Collaborators: Professor Joseph Taube, PhD; Baylor University

“Antimicrobial Encapsulated Nanomaterials”

• There are many efforts to eradicate vectors that spread disease, but most focus on humans

• Vectors for plant pathogens are also detrimental, especially to the agriculture industry

• We are developing and evaluating a series of prototype Antimicrobial Encapsulated Nanoparticle Systems (AENS) to combat citrus greening disease caused by Diaphorina citri and Candidatus Liberibacter

Investigator(s): Thelma Ameh, Kusy Zarzosa, JP Valle, Dr. Swarna Shikha

Collaborators: Dr. W. Evan Braswell, PhD; Animal and Plant Health Inspection Service, USDA

Completed Research Projects

"Comprehensive physicochemical characterization of nickel colloid and nickel oxide nanomaterials: Challenges and opportunities for environmental & occupational health”

• We comprehensively characterized four nickel nanomaterials

• Key chemical properties included composition, surface reactivity, and ion-particle ratio

• Key physical properties included size distribution, morphology, and aggregation state

Investigator(s): Marina Mulenos George, Desirae Carrasco

Collaborators: NiPERA

"Mechanistic analysis of nanomaterial induced mitophagy”

• Nanomaterials exert toxicity by increasing reactive oxygen species (ROS) production

• This disrupts the homeostasis of mitochondria

• We analyze mitophagy pathways and the electron transport chain following exposure

• Techniques used include Western blotting, PCR, and ELISA

Investigator(s): Henry Lujan, Luke Reardon

“Determining the biological mechanisms of action for environmental exposures: Applying CRISPR/Cas9 to toxicological assessments”

• As nanomaterials evolve, they need to meet public health and safety recommendations

• Toxicity mechanisms can be better understood by applying techniques used in other fields

• We will use systems such as CRISPR/Cas9 for single gene knock-outs, CRISPR interference, and CRISPR libraries

Investigator(s): Henry Lujan, Luke Reardon

Collaborator(s): Dr. Saber Hussain, PhD, ATS; U.S. Air Force Research Laboratory

"Comparing the basal-level gene and protein expressions of human cells”

• Cell culture based models are routinely used to measure the hazards of particle systems

• There is a need for better guidelines on which cell lines are appropriate for specific experiments

• We will analyze cells retrieved from varying depths of the pulmonary system and in varying diseased states

Investigator(s): Henry Lujan, Sahar Pradhan

“Characterizing nanoparticle–protein coronas: Using analytical methods to detect & identify proteins adsorbed onto gold particle surfaces”

• A challenge with nanomaterial drug carriers is the surface adsorption of proteins in the blood

• The “protein corona” is postulated to critically alter drug performance or toxicity

• We aim to identify proteins that make up the corona and understand how surface chemistry affects formation

Investigator(s): Marina Mulenos George, Lauren Pitts