Chemistry Instructor, Department of Physical Sciences
Associate Director, Center for Nanobiotechnology Research
Nanostructured biomaterials with emphasis on biodegradable and bioactive matrices for bone tissue repair and regeneration: Scaffold design is an area of focus primarily because tissue scaffolds provides structure for cell attachment, guides cell proliferation and differentiation, and mimic’s the native extracellular matrix (ECM) of bone. Polymeric scaffolds made from biodegradable polymers are engineered to facilitate repair of damaged tissues. The scaffolds are designed to provide an environment conducive to cell growth which helps in expediting the tissue regeneration process. The success rate depends upon the ability of scaffolds to mimic the functionality of natural ECM. The natural ECM plays an important role on morphogenesis, tissue development, and angiogenesis since it acts as binding sites for many proteins such as cytokine molecules and growth factors. The goal of this project is to develop bioactive polymeric scaffolds based on polycaprolactone (PCL), modified carbon nanofibers (mCNF) and hydroxyapatite (HA) that mimic the efficiency of natural ECM in modulating the cellular and molecular markers during bone-tissue regeneration. Nanocomposite scaffolds based on PCL/mCNF will be fabricated using electrospinning to achieve improved mechanical properties and uncompromised cell growth for bone tissue engineering applications. A nanoscaled HA coating will be electrophoretically deposited onto the composite nanofibers to further promote bioactivity and osteoconductivity. The response of human mesenchymal stem cells to the scaffolds and the release characteristics of bone morphogenic proteins adsorbed onto the HA surface will be studied. The mechanism of adsorption and release will be studied in order to optimize the process.
Development of nanobiomaterials for drug delivery: This study is aimed at understanding how to release therapeutics in a controlled manner from nanofibrous polymeric tissue scaffolds fabricated by electrospinning polyvinyl alcohol (PVA) encapsulated with varying concentrations of detonation nanodiamonds (DND). DND’s have recently garnered attention as drug delivery vehicles. The surface energy of the DND’s makes it relatively straightforward to adsorb or covalently attach therapeutic molecules. Earlier work showed that drugs encapsulated into the nanofibers alone exhibited a burst release. It is anticipated that the DND’s will help us achieve a more sustained release. The toxicity of the DND’s to several different cell lines showed little compromise in the cell’s viability at low DND concentrations. Our research focuses on the potential use of DND to deliver therapeutics, the compatibility concerns with using carbon based nanomaterials (i.e., cytotoxicity), and the fabrication and characterization of these novel nanocomposite scaffolds for drug delivery.
Learn more (.pdf) about Nyairo's research.
- Zaynah Welcome, Hongzhuan Wu, Elijah Nyairo, Christian Rogers, Derrick Dean, Kennedy Wekesa, Karyn Gunn, Robert Villafane. “Cytotoxicity and Cell adhesion Properties of Human Mesenchymal Stem Cells in Electrospun Nanofiber Polymer Scaffolds”. International Journal of Advanced Biotechnology and Bioinformatics (2012) – In Press
- Himani D. Deshpande, Derrick R. Dean, Vinoy Thomas, William C. Clem, Moncy V. Jose, Elijah Nyairo, Manoj Mishra. ”Carbon nanofiber reinforced polycaprolactone fibrous meshes by electrostatic co-spinning” Current Nanoscience 8, 5 (2012) 753-761
- Renu Bhatt, Vinoy Thomas, Derrick Dean, Elijah Nyairo, Manoj Mishra “Role of PPARs as Chemotherapeutics and Anticancer Molecules” International Journal of Advanced Biotechnology and Bioinformatics (2012) – In Press
- Himani Deshpande, Carrie Schindler, Derrick Dean, William Clem, Elijah Nyairo, Manoj Mishra, Vinoy Thomas “Nanocomposite scaffolds based on electrospun PCL/CNF/HA by electrosphoretic deposition” Journal of Biomaterials and Tissue Engineering Vol 1, (2011) 177-184
- Vinoy Thomas, Thomas Donahoe, Elijah Nyairo, Derrick R. Dean, Yogesh K. Vohra. “Electrospinning of Biosyn® Based Tubular Conduits: Structural, Morphological ans Mechanical Characterizations”, Acta Biomaterialia 7, 5 (2011) 2070–2079
- Vinoy Thomas, Bini Mathew, Derrick R. Dean, Elijah Nyairo “Biodegradable Polymeric Nano-Biomaterials for Cancer Therapeutic Applications” in Signaling, Gene Regulation and Cancer, (2011) Nova Science Publishers, Inc., Hauppauge, N.Y (ISBN 978-1-61942-088-5)
- Moncy V. Jose, Vinoy Thomas, Yuanyuan Xu, Susan Bellis, Elijah Nyairo, Derrick Dean “Aligned Bioactive Multi-Component Nanofibrous Nanocomposite Scaffolds for Bone Tissue Engineering” Macromolecular Biosciences 10, 4 (2010), 433-444
- Abdalla M, Dean D, Theodore M, Fielding J, Nyairo E, Price G “Magnetically Processed Carbon Nanotube/Epoxy Nanocomposites: Morphology, Thermal and Mechanical Properties” Polymer 51, 7 ( 2010) 1614-1620
- Green K J, Dean D, Vaidya U K, Nyairo E. “Multiscale fiber reinforced composites based on a carbon nanofiber/epoxy nanophased polymer matrix: Synthesis, mechanical and thermomechanical behavior” Composites Part A: Applied Science and Manufacturing 40, 9 (2009) 1470-1475
- Jose M V, Thomas V, Dean D, Nyairo E. “Fabrication and characterization of aligned nanofibrous PLGA/Collagen blends as bone tissue scaffolds” Polymer 50, 15 (2009) 3778-3785
- Jose M V, Thomas V, Johnson K, Dean D, Nyairo E. “Aligned Nanofibrous PLGA/HA as Nanofibrous Nanocomposite Scaffolds for Bone Tissue Engineering” Acta Biomaterialia 5, 1 (2009) 305-315
- Abdalla M, Dean D, Robinson P, Nyairo E. “Cure Behavior of Epoxy/MWCNT Nanocomposite: The Effect of Nanotube Surface Modification”. Polymer 49, 15 (2008) 3310 – 3317
- Abdalla M, Dean D, Adibempe D, Nyairo E, Robinson P, Thompson, G. “The Effect of Interfacial Chemistry on Molecular Mobility and Morphology of Multiwalled Carbon Nanotubes Epoxy Nanocomposite” Polymer 48, 19 (2007) 5662 – 5670
- Jose M V, Dean D, Tyner J, Price G, Nyairo E. “Polypropylene/Carbon Nanotube Nanocomposite Fibers: Process-Morphology-Property relationships”. J Appl Polym Sci, 103, 6 (2007) 3844 – 3850
- Thomas V, Jagani S, Johnson K, Jose M V, Dean D, Vohra Y, Nyairo E. “Electrospun Bioactive Nanocomposite Scaffolds of Polycaprolactone and Nanohydroxyapatite for Bone Tissue Engineering”. J Nanosci Nanotechnol 6, 2 (2006) 487– 493
- Dean D, Obore A M, Richmond S, Nyairo E. “Multiscale Fiber-Reinforced Nanocomposites: Synthesis, Processing and Properties”. Compos Sci Technol, 66, 13 (2006) 2135 – 2142
- Dean D, Walker R, Theodore M, Hampton E, Nyairo E. “Chemorheology and Properties of Epoxy/Layered Silicate Nanocomposites.” Polymer 46, 9 (2005) 3014 – 3021.