Biography

Our research focus is to develop exosome-based diagnostic and therapeutic strategies and stem cell–derived regenerative approaches for neurodegenerative and malignant brain diseases, including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and glioblastoma.

We first demonstrated that human neural stem cells transplanted into aged rats differentiated into neurons and significantly improved cognitive function. To overcome the ethical and technical challenges associated with fetal and embryonic stem cells, we established a method to generate neural cells from adult human mesenchymal stem cells by over expression of an embryonic stem cell gene. We further advanced this autologous cell-therapy concept through a small-molecule compound that dramatically enhances endogenous neural stem cell proliferation and neurogenesis in the aged brain. 

Our current studies extend these findings to the molecular and nanoscale levels through exosome research. We discovered that exosomal DNA cargo can reflect disease states and serve as non-invasive biomarkers detectable in saliva from glioblastoma patients. Building on this concept, we are developing saliva-based exosome assays for the early diagnosis of Alzheimer’s disease. In parallel, we have established exosome-mediated drug delivery systems capable of crossing blood-brain barrier that transport therapeutic agents, such as shRNA targeting NANOG, and OCT4 to suppress stemness and drug resistance in glioblastoma cancer stem cells. 

In addition, our laboratory investigates the mechanisms regulating stemness, neuroinflammation, and neural differentiation, focusing on molecules such as reelin, which is reduced in schizophrenia and autism, and amyloid-β precursor protein, which contributes to Alzheimer’s pathology. These studies reveal how such factors control stem-cell migration and differentiation under both normal and disease conditions and guide the development of novel molecular and regenerative therapies. 

By combining stem cell and exosome technologies with advanced biosensing tools we aim to transform therapeutic strategies for brain disorders from symptom management to true regeneration and cure. 

Recent Publications

Below is a selection of Dr. Sugaya’s recent representative publications illustrating his current research in exosome biology, glioblastoma, Alzheimer’s disease, and regenerative neuroscience. 

1. Vaidya M., Smith J., Pessaia J., Field M., Sugaya K. Atypical behavior of recurrent glioblastoma tumor cells with a highly adherent radial glial phenotype. CNS Oncology. 2025; 14(1): 2559576. 

2. Smith J., Field M., Sugaya K. Brain-homing peptide expression on the membrane enhances the delivery of exosomes to neural cells and tissue. Neuroglia. 2025; 6(1): 3.

3. Ambrosius H., Vaidya M., Joshua F., Bajaj A., Zhai L., Sugaya K., Huo Q. Rapid isolation and characterization of exosomes through a single-step, label-free protein biomarker analysis. ACS Applied Bio Materials. 2025 Apr 9.

4. Vaidya M., Kimura A., Bajaj A., Sugaya K. 3′-UTR sequence of exosomal NANOGP8 DNA as an extracellular-vesicle localization signal. International Journal of Molecular Sciences. 2024; 25(13): 7294.

5. Smith J., Field M., Sugaya K. Suppression of NANOG expression reduces drug resistance of cancer stem cells in glioblastoma. Genes. 2023; 14(6): 1276.

6. Vaidya M., Sreerama S., Gonzalez-Vega M., Smith J., Field M., Sugaya K. Coculture with neural stem cells may shift the transcription profile of glioblastoma multiforme toward cancer-specific stemness. International Journal of Molecular Sciences. 2023; 24(4): 3242.

7. Vaidya M., Smith J., Field M., Sugaya K. Analysis of regulatory sequences in exosomal DNA of NANOGP8. PLoS One. 2023; 18(1): e0280959.

8. Sayeed N., Sugaya K. Exosome-mediated Tom40 delivery protects against hydrogen-peroxide–induced oxidative stress by regulating mitochondrial function. PLoS One. 2022; 17(8): e0272511.

9. Vaidya M., Sreerama S., Gaviria M., Sugaya K. Exposure to a pathological condition may be required for the cells to secrete exosomes containing mtDNA aberration. Journal of Nucleic Acids. 2022; Article ID 7960198.

10. Carrick F.R., Azzolino S.F., Hunfalvay M., Pagnacco G., Oggero E., D’Arcy R.C.N., Abdulrahman M., Sugaya K. The pupillary light reflex as a biomarker of concussion. Life (Basel). 2021; 11(10): 1104.

11. Carrick F.R., Valerio L.S.A., Gonzalez-Vega M.N., Engel D., Sugaya K. Accelerated wound healing using a novel far-infrared ceramic blanket. Life (Basel). 2021; 11(9): 878. 

12. Vaidya M., Sugaya K. Methods for the detection of circulating pseudogenes and their use as cancer biomarkers. Methods in Molecular Biology. 2021; 2324: 339–360.

13. Vaidya M., Sugaya K. DNA associated with circulating exosomes as a biomarker for glioma. Genes. 2020; 11(11): 1276.

14. Valerio L.S.A., Sugaya K. Xeno- and transgene-free reprogramming of mesenchymal stem cells toward the cells expressing neural markers using exosome treatments. PLoS One. 2020; 15(10): e0240469.

15. Vaidya M., Sugaya K. Differential sequences and single-nucleotide polymorphism of exosomal SOX2 DNA in cancer. PLoS One. 2020; 15(2): e0229309. 

For more publication information, please visit Pubmed.