Senior Scientist

Department of Natural Products and Medicinal Chemistry

CSIR-Indian Institute of Chemical Technology Hyderabad

Assistant Professor of Chemical Sciences

Academy of Scientific & Innovative Research (AcSIR)

Hyderabad 500007, India

Dr Avijit Jana

OUR LATEST RESEARCH

Organic near-infrared (NIR) fluorescent probes have been recognized as an emerging class of materials exhibiting a great potential in advanced bio-analytical applications. However, synthesizing such organic probes that simultaneously work in the NIR spectral range and have large stokes shift, high stability in the biological system, and high photostability have been proven challenging. In this work, aggregation induced excimeric NIR emission in aqueous media was observed from a suitably substituted perylene monoimide (PeIm) dye. Controlled entrapment of the dye into pluronic F127 micellar system to preserve its monomeric emission in aqueous media was also established.Tuning the morphology along with the formation of colloidosome microcapsules by the controlled self-aggregation of PeIm NPs in aqueous suspension was demonstrated successfully.

Morphology Tuning of Organic Nano-Particles

We designed a new photoresponsive real time monitoring nanoparticle based on photoluminescent Silicon Quantum Dots (SiQDs) using onitrobenzyl (ONB) derivative as phototrigger for the controlled release of anticancer drug chlorambucil (Cbl). The strong fluorescence of SiQDs was initially quenched by ONB. Upon irradiation ONB triggered the release of drug causing switching on the fluorescence of SiQDs to monitor the drug release. We reported a new and simple strategy to synthesise amine functionalised silicon quantum dots and covanlently conjugated phototrigger ONB with caged anticancer drug Cbl on to it. Newly designed photoresponsive theranostic ONBCbl-SiQDs performed three important functions: (i) nanocarrier for drug delivery, (ii) controlled drug release under both one photon and two-photon excitation, and (iii) photoswitchable fluorescent nanoparticles for real-time monitoring of drug release based on photoinduced electron transfer (PET) process.

We developed excellent charge reversal photoresponsive nanoparticles for targeted delivery of the anticancer drug chlorambucil. The charge reversal photoresponsive nanoparticles were constructed using two main ingredients, namely folic acid decorated mesoporous silica and quinoline chromophore. The newly synthesized quinoline chromophore performed three important roles, i.e., (i) fluorescent chromophore for cell imaging, (ii) phototrigger for regulated release of anticancer drug, and (iii) charge reversal based on its zeta potential for nuclear localization. Furthermore, folic acid decorated mesoporous silica facilitated active internalization of the drug inside the cancer cells. In vitro biological studies reveal that our photoresponsive DDS could deliver the anticancer drug chlorambucil into the tumor cells, killing the cancer cells by both one photon>365 nm) and two photon (>675 nm) irradiation.

A versatile heterogeneous photocatalysis protocol was developed by using ruthenium bipyridyl tethered porous organosilica (Ru-POS). The versatility of the Ru-POS catalyst in organo-photocatalysis was explored by (i) oxidative aromatization of Hantzsch ester, (ii) reductive dehalogenation of alkyl halides, and (iii) functional group interconversion (FGI) of alcohols to alkyl halides.

Magnetic Fe3O4 nanoparticles embedded in graphene oxide (Fe3O4@GO) behave as a highly efficient and reusable heterogeneous nanocatalyst for alkene hydrogenation in EtOH at 80 oC temperature using hydrazine hydrate as the hydrogen source to deliver the corresponding alkanes in good to excellent yields together with high TOF (>4450 h-1) within a 4–20 h reaction time.

Small molecule near-infrared (NIR) fluorescent probes have been developed as potential bio-materials having profound applications both in diagnosis and clinical practice. Herein, we wish to disclose a highly photostable ultra-bright NIR fluorescent probe for the specific detection of lysosome in numerous cancerous and normal cell lines. Further, the applicability of the developed NIR probe has been evaluated for in vivo deep-tissue imaging.

Lysosome specific NIR probe

Welcome to the Photochemistry and Photobiology Lab – Where the Possibilities are as Boundless as the Light Itself.

At our lab, we are dedicated to exploring the fascinating intersection of photochemistry and biology to design innovative photoresponsive drug delivery and bio-imaging systems. Harnessing the power of light, we aim to develop novel strategies for targeted drug delivery and imaging with the ultimate goal of improving therapeutic outcomes and enhancing patient care.

In our research, we leverage the unique properties of photoresponsive molecules to achieve precise control over drug release and activation. By engineering smart drug delivery systems that respond to specific wavelengths of light, we can tailor treatment regimens to individual patient needs, minimizing side effects and maximizing efficacy.

Our interdisciplinary team brings together expertise in chemistry, biology, and materials science to tackle complex challenges in drug delivery and biomedical research. Through collaborative efforts and cutting-edge technologies, we strive to push the boundaries of knowledge and make meaningful contributions to the field of photomedicine.

Join us as we embark on an exciting journey of discovery, innovation, and translation in the Photochemistry and Photobiology Lab. Together, we can illuminate new pathways toward more effective and personalized therapeutics for a healthier future.