Our Research

Our team conducts research at the interface of Chemistry, Material Science, and Biological Sciences. We focus on efficient control of the structure, function, and interactions with the highest possible precision to develop multifunctional and biocompatible nanomaterials. Our design principles are inspired by the economy, efficiency, and error-free structure formation in nature. Beyond structure formation, we mimic the unique mechanical behavior of soft biological tissues and biochemical cues for advanced tissue culture scaffolds. The building blocks and components include but are not limited to biopolymers, nanocellulose, block-copolymers, metal nanoparticles, and biological colloidal particles. We use cutting-edge nanotechnological characterization, including state-of-the-art electron microscopy, for advanced material characterization.
Our core research areas are:

  • Precision Nanomaterials
  • Precision Cancer Research
  • Biopolymer-based  materials for optics and photonics
  • Cryogenic transmission electron microscopy (cryo-TEM) and electron tomography

Precision Nanomaterials

We use atomically precise noble metal (gold and silver) nanoclusters and narrow size dispersed plasmonic metal nanoparticles. We are developing concepts and methods for precision nanoparticle self-assemblies across length scales. We tune the functionalities of the organic ligands to control the inter-nanoparticle interactions. Specifically, we use hydrogen bonding, electrostatic interactions, and metal coordination as major driving forces alone or combinations of more than one interaction. We are developing one-dimensional nanowires, 2D colloidal crystals, or 3D colloidal frameworks. We amplify optoelectronic properties and mechanical performance through self-assembly and develop approaches for various composite chiral plasmonic superstructures.

Related publications: Small 2021, Adv. Opt. Mater 2019,  Adv. Funct. Mater. 2018, Angew. Chem. Int. Ed. 2018, Angew. Chem. Int. Ed. 2016

Precision Cancer Research

As of 2020, breast cancer is the most frequently diagnosed cancer type and is one of the leading causes of cancer-related deaths in women. Despite the high incidence of the disease, the average 5-year survival rate of breast cancer patients with the early-stage, non-metastatic disease is over 80%. However, this survival rate falls below 25% in patients with metastasis. Metastatic breast cancer is therefore considered practically incurable and is responsible for more than 90% of tumor-related deaths, often due to the impairment of vital organ functions.  Our team is actively developing lab-on-a-chip (LOC) system-based in vitro models to study the multistep and complex metastasis process. The ultimate aim is to develop a suitable model to study breast cancer metastasis cascade and preclinical model for metastatic cancer treatment. We actively develop hydrogel-based three-dimensional extracellular matrices (ECM) mimic for a cancer cell, tissue, and explant culture. We utilize molecular and polymer hydrogels with unique rheological properties, chemical functionalities, and biochemical cues to study the cell-matrix interactions. Particularly, we mimic the non-linear viscoelasticity of biological systems in artificial scaffolds. The hydrogels are used for 3D tissue culture, patient-derived tissue cultures, and organoid culture.

Related publications: Nat. Commun. 2021,  Cancer Res. 2021

Biopolymer-based materials for optics and photonics

We utilize naturally abundant, renewable, and sustainable molecular, polymeric, and colloidal level building blocks. At the molecular level, utilize plant sterols and terpenoids for designing conformationally rigid surfactants with unique self-assembly properties. We study self-assembly enhanced antimicrobial properties, anti-cancer properties, and gelation.  For polymer-level components, we use cellulose-derived biopolymers for optomechanically tunable gels or fibers. At the colloidal level, we utilize various nanocelluloses, viz., cellulose nanocrystal (CNCs), nanofibrillated cellulose (NFC), and bacterial cellulose (BC).

Related publications: Small 2021, Adv. Mater. 2021   Adv. Mater. 2018    Biomacromolecules 2018    ACS Macro Lett. 2019

Cryogenic Transmission Electron Microscopy

Transmission Electron microscopy (EM) is a powerful imaging technique to study a diverse range of synthetic and biological materials. Biological samples or synthetic soft nanostructures lead to numerous drying artifacts and collapsed structures.  The cryogenic sample preparation method allows imaging of the biological materials and soft nanomaterials near their native state or frozen state with reduced artifacts. The specimens are rapidly frozen using a liquid propane/ethane mixture, resulting in thin (below 130 nm) and transparent vitreous ice. This method is suitable for a wider range of particles such as virus particles, polymer micelles, vesicles, nanotubes, protein assemblies.

Related Publications: ACS Nano 2019  Adv. Mater. 2019  J. Am. Chem. Soc. 2018   Nat. Commun. 2017

Electron Tomography

TEM images of three-dimensional (3D) objects produce superimposed two-dimensional (2D) orthogonal projections. Importantly, in transmission electron microscopy (TEM) images, the 2D projection often contains high-resolution structural details. A limited amount of correct internal structural information is obtained from the 2D images because of the superimposed nature. To overcome the above limitations, we use electron tomography to achieve 3D reconstruction using a series of 2D projections. Electron tomography thus allows the most realistic and high-resolution structural and morphological features of nanostructures near-atomic resolution.

Related Publications: Angew. Chem. Int. Ed. 2020    ACS Nano 2019    Angew. Chem. Int. Ed. 2018