MCHRI Post-doctoral Fellow

Honors & Awards

  • MCHRI Post-doctoral Fellowship Award, Stanford University (2021)
  • International Travel Grant Award, Department of Science and Technology, Science and Engineering Research Board (DST-SERB) (2019)
  • Inspire Senior Research Fellowship Award, Department of Science and Technology, Government of India (2018)
  • Senior Research Fellow Award, Council of Scientific and Industrial Research (CSIR), Government of India (2017)
  • Best Poster Presentation Award, Indian Institute of Science (IISC), Bangalore India (2016)
  • Inspire Junior Research Fellowship Award, Department of Science and Technology, Government of India (2016)

Boards, Advisory Committees, Professional Organizations

  • Member, American Chemical Society (ACS), USA (2019 - Present)
  • Member, Royal Society of Chemistry (RSC), UK (2019 - Present)
  • Member, Indian Society for Technical Education (ISTE), India (2008 - 2012)
  • Member, International Society of Optics and Photonics (SPIE), USA (2017 - Present)
  • Member, Materials Research Society (MRS), USA (2019 - Present)

Professional Education

  • Doctor of Philosophy, Pondicherry Central University, Nanoscience and Technology (2020)
  • Master of Technology, Pondicherry Central University, Nanoscience and Technology (2014)
  • Bachelor of Technology, PSG College of Technology, Anna University, Biotechnology (2012)

Stanford Advisors

All Publications

  • Human Umbilical Cord Wharton's Jelly-Derived Mesenchymal Stem Cells Labeled with Mn2+ and Gd3+ Co-Doped CuInS2-ZnS Nanocrystals for Multimodality Imaging in a Tumor Mice Model ACS APPLIED MATERIALS & INTERFACES Chetty, S., Praneetha, S., Murugan, A., Govarthanan, K., Verma, R. 2020; 12 (3): 3415–29


    Mesenchymal stem cell (MSCs) therapy has recently received profound interest as a targeting platform in cancer theranostics because of inherent tumor-homing abilities. However, the terminal tracking of MSCs engraftment by fluorescent in situ hybridization, immuno-histochemistry, and flow-cytometry techniques to translate into clinics is still challenging because of a dearth of inherent MSCs-specific markers and FDA approval for genetic modifications of MSCs. To address this challenge, a cost-effective noninvasive imaging technology based on multifunctional nanocrystals (NCs) with enhanced detection sensitivity, spatial-temporal resolution, and deep-tissue diagnosis is needed to be developed to track the transplanted stem cells. A hassle-free labeling of human umbilical cord Wharton's Jelly (WJ)-derived MSCs with Mn2+ and Gd3+ co-doped CuInS2-ZnS (CIS-ZMGS) NCs has been demonstrated in 2 h without requiring an electroporation process or transfection agents. It has been found that WJ-MSCs labeling did not affect their multilineage differentiation (adipocyte, osteocyte, chondrocyte), immuno-phenotypes (CD44+, CD105+, CD90+), protein (β-actin, vimentin, CD73, α-SMCA), and gene expressions. Interestingly, CIS-ZMGS-NCs-labeled WJ-MSCs exhibit near-infrared (NIR) fluorescence with a quantum yield of 84%, radiant intensity of ∼3.999 × 1011 (p/s/cm2/sr)/(μW/cm2), magnetic relaxivity (longitudinal r1 = 2.26 mM-1 s-1, transverse r2 = 16.47 mM-1 s-1), and X-ray attenuation (78 HU) potential for early noninvasive multimodality imaging of a subcutaneous melanoma in B16F10-tumor-bearing C57BL/6 mice in 6 h. The ex vivo imaging and inductively coupled plasma mass-spectroscopy analyses of excised organs along with confocal microscopy and immunofluorescence of tumor results also significantly confirmed the positive tropism of CIS-ZMGS-NCs-labeled WJ-MSCs in the tumor environment. Hence, we propose the magnetofluorescent CIS-ZMGS-NCs-labeled WJ-MSCs as a next-generation nanobioprobe of three commonly used imaging modalities for stem cell-assisted anticancer therapy and tracking tissue/organ regenerations.

    View details for DOI 10.1021/acsami.9b19054

    View details for Web of Science ID 000509428300011

    View details for PubMedID 31875453

  • Noninvasive Tracking and Regenerative Capabilities of Transplanted Human Umbilical Cord-Derived Mesenchymal Stem Cells Labeled with I-III-IV Semiconducting Nanocrystals in Liver-Injured Living Mice ACS APPLIED MATERIALS & INTERFACES Chetty, S., Praneetha, S., Govarthanan, K., Verma, R., Murugan, A. 2019; 11 (9): 8763–78


    Acute liver injury is a critical syndrome ascribed to prevalent death of hepatocytes and imperatively requires liver transplantation. Such a methodology is certainly hampered due to the deficit of healthy donors. In this regard, stem cell-based regenerative therapies are attractive in repairing injured tissues and organs for medical applications. However, it is crucial to understand the migration, engraftment, and regeneration capabilities of transplanted stem cells in the living animal models. For the first time, we demonstrate rapid labeling of umbilical cord-derived mesenchymal stem cells (MSCs) with near-infrared (NIR)-fluorescent CuInS2-ZnS nanocrystals (CIZS-NCs) to develop innovative nanobioconjugates (MSCs-CIZS-NBCs) that exhibit 98% labeling efficiency. Before nanobioconjugate synthesis, the pristine CIZS-NCs were prepared via a two-step, hot-injection, rapid and low-cost domestic-microwave-refluxing (MW-R) method within 6 min. The as-synthesized CIZS-NCs display high photoluminescence quantum yield (∼88%) and long-lived lifetime (23.4 μs). In contrast to unlabeled MSCs, the MSCs-CIZS nanobioconjugates show excellent biocompatibility without affecting the stemness, as confirmed by cell viability, immunophenotyping (CD44+, CD105+, CD90+), multi-lineage-specific gene expressions, and differentiation into adipocytes, osteocytes, and chondrocytes. The in vivo fluorescence tracking analyses revealed that the MSCs-CIZS-NBCs after tail-vein injection were initially trapped in the lungs and gradually engrafted in the injured liver within 2 h. The regeneration potential of MSCs-CIZS-NBCs was confirmed via renewal of the portal tract composed of portal veins, bile ducts, and hepatic arteries around the hepatocytes. Consequently, no apparent inflammations, necrosis, or apoptosis was observed in the acetaminophen (APAP)-induced liver-injured BALB/c mice model over 3 days after transplantation, as corroborated using laser-scanning confocal microscopy and histopathological and hematological analyses. Hence, our innovative NIR-fluorescent MSCs-CIZS-NBCs offer an off-the-self technology for noninvasive tracking of transplanted MSCs in an acute-liver-injured animal model for future image-guided cell-therapies.

    View details for DOI 10.1021/acsami.8b19953

    View details for Web of Science ID 000460996900010

    View details for PubMedID 30741534

  • Microwave-Assisted Synthesis of Quasi-Pyramidal CuInS2-ZnS Nanocrystals for Enhanced Near-Infrared Targeted Fluorescent Imaging of Subcutaneous Melanoma ADVANCED BIOSYSTEMS Chetty, S., Praneetha, S., Murugan, A., Govarthanan, K., Verma, R. S. 2019; 3 (1): e1800127


    Near-infrared (NIR) fluorescent CuInS2 -ZnS nanocrystals (CIZS NCs) are synthesized via an ultra-fast, non-injection microwave (MW)-assisted nanoalloying process at 230 ºC within 5 min using 1-dodecanethiol (DDT) as both the sulfur source and solvent under solvothermal (ST) condition. The structural and surface analyses reveal that DDT-functionalized CIZS NCs exhibit quasi-pyramids of tetragonal-phase with well-defined facets. The DDT-functionalized CIZS NCs present a photoluminescence quantum yield (PLQY) of 76% and a long-lived fluorescence lifetime of ≈0.6 µs in organic-phase. Subsequently, DDT-functionalized CIZS NCs are phase-transferred via ligand-exchange using 11-mercaptoundecanoic acid (MUA) into water-soluble MUA-CIZS NCs that exhibit a substantial PLQY of 55%. In addition, the NIR-fluorescent MUA-functionalized CIZS NCs in conjugation with folic acid (FA), as a tumor-targeting ligand, demonstrates enhanced tumor-targeted imaging ability. The FA-MUA-CIZS NC conjugates exhibit a cell viability of ≈75% even at the highest concentration of 1 mg mL-1 and a labeling efficiency of 95.4%. The in vivo imaging results corroborate that FA-MUA-CIZS NCs conjugates are actively targeted to folate receptor-positive B16F10 tumor-bearing C57BL/6 mice in 2 h. The histopathological and hematological studies confirm no significant changes in tissue architecture and blood biochemical parameters. The confocal microscopy studies reveal deep penetration and uniform distribution of FA-MUA-CIZS NCs conjugates in subcutaneous melanoma.

    View details for DOI 10.1002/adbi.201800127

    View details for Web of Science ID 000455812800008

    View details for PubMedID 32627345

  • Transition Metal Ion (Mn2+, Fe2+, Co2+, and Ni2+)-Doped Carbon Dots Synthesized via Microwave-Assisted Pyrolysis: A Potential Nanoprobe for Magneto-fluorescent Dual-Modality Bioimaging ACS BIOMATERIALS SCIENCE & ENGINEERING Pakkath, S., Chetty, S., Selvarasu, P., Murugan, A., Kumar, Y., Periyasamy, L., Santhakumar, M., Sadras, S., Santhakumar, K. 2018; 4 (7): 2582–96
  • Sustainable, Rapid Synthesis of Bright-Luminescent CuInS2-ZnS Alloyed Nanocrystals: Multistage Nano-xenotoxicity Assessment and Intravital Fluorescence Bioimaging in Zebrafish-Embryos (vol 6, 26078, 2016) SCIENTIFIC REPORTS Chetty, S., Praneetha, S., Basu, S., Sachidanandan, C., Murugan, A. 2016; 6: 28607

    View details for DOI 10.1038/srep28607

    View details for Web of Science ID 000378492100001

    View details for PubMedID 27345563

    View details for PubMedCentralID PMC4921864

  • One-pot microwave-assisted in situ reduction of Ag+ and Au3+ ions by Citrus limon extract and their carbon-dots based nanohybrids: a potential nano-bioprobe for cancer cellular imaging RSC ADVANCES Sajid, P. A., Chetty, S., Praneetha, S., Murugan, A., Kumar, Y., Periyasamy, L. 2016; 6 (105): 103482–90

    View details for DOI 10.1039/c6ra24033j

    View details for Web of Science ID 000387726500080