Showing papers by "Nikhil R. Jana published in 2022"
TL;DR: It is shown that anisotropic shape and Au nanoparticle conjugation can enhance the piezocatalytic property of a calcium phosphate nanomaterial by 10 times and the performance approaches that of the bulk/nanoparticle form of well-known BaTiO3.
Abstract: Piezocatalytic materials have considerable application potential in wireless therapy. Most of these applications require biocompatible nanomaterials for in vivo targeting and control of intracellular processes. However, the piezocatalytic performance of a material decreases at a nanometer size regime, and most of the biocompatible materials have poor piezocatalytic efficiency. In particular, hydroxyapatite or calcium phosphate-based nanomaterials have weak piezocatalytic properties that limit the biomedical application potential. Here, we show that anisotropic shape and Au nanoparticle conjugation can enhance the piezocatalytic property of a calcium phosphate nanomaterial by 10 times and the performance approaches that of the bulk/nanoparticle form of well-known BaTiO3. The colloidal form of calcium phosphate nanowires/nanorods/nanospheres (2-5 nm diameter and 30-1000 nm length) and their Au nanoparticle (5-8 nm) composites are prepared, and their piezoelectric properties have been investigated with piezoresponse force microscopy. It has been observed that the anisotropic nanowire structure of calcium phosphate can enhance the piezoelectric property by 2 times and Au nanoparticle conjugation can enhance it up to 10 times with a piezoelectric constant value of 72 pm/V, which is close to the value of the bulk/nanoparticle form of BaTiO3. This enhanced piezoelectric property is shown to enhance the piezocatalytic reactions by 10 times. The approach has been used to design colloidal nano-bioconjugate for selective labeling of cancer cells, followed by wireless cell therapy via medical-grade ultrasound-based intracellular reactive oxygen species generation. The developed approach and material can be extended for wireless therapeutic applications and for controlling intracellular processes.
11 citations
TL;DR: Antimicrobial and cytotoxic effect of zinc oxide nanomaterials are popularly thought due to zinc ion leaching, but the exact mechanism of cytotoxicity is controversial and not fully understood.
Abstract: The antimicrobial and cytotoxic effects of zinc oxide nanomaterials are popularly thought to be occurring due to zinc ion leaching, but the exact mechanism of cytotoxicity is controversial and not fully understood. Recent studies have shown that oxygen vacancy defects in the nanoscale zinc oxide can generate reactive oxygen species (ROS) under dark conditions and may induce cytotoxicity. In this work, we show that the cytotoxicity of zinc oxide nanoparticles is directly correlated with oxygen vacancy defects that generate ROS under dark conditions. More specifically, we designed zinc oxide nanoparticles with controlled oxygen vacancy defects by controlled gallium doping and showed that the ROS generation property of zinc oxide nanoparticles under dark conditions is directly correlated with oxygen vacancy defects. Further studies show that superoxide radicals and hydrogen peroxide are the primary ROS that are produced under dark conditions. These colloidal nanoparticles are used for cell labeling and therapy via intracellular ROS generation without any light exposure. The designed nanoparticle can be used for the formulation of advanced antibacterial and antimicrobial materials and other cell therapy applications.
6 citations
5 citations
TL;DR: A guanidinium-terminated polyaspartic acid micelle is reported for direct cytosolic delivery of protein and DNA by forming a nano-assembly, and it is observed that <200 nm size of colloidal assembly with near-zero surface charge is critical for efficient cytosol delivery.
Abstract: Direct cytosolic delivery of large biomolecules that bypass the endocytic pathways is a promising strategy for therapeutic applications. Recent works have shown that small-molecule, nanoparticle, and polymer-based carriers can be designed for direct cytosolic delivery. It has been shown that the specific surface chemistry of the carrier, nanoscale assembly between the carrier and cargo molecule, good colloidal stability, and low surface charge of the nano-assembly are critical for non-endocytic uptake processes. Here we report a guanidinium-terminated polyaspartic acid micelle for direct cytosolic delivery of protein and DNA. The polymer delivers the protein/DNA directly to the cytosol by forming a nano-assembly, and it is observed that <200 nm size of colloidal assembly with near-zero surface charge is critical for efficient cytosolic delivery. This work shows the importance of size and colloidal property of the nano-assembly for carrier-based cytosolic delivery of large biomolecules.
4 citations
TL;DR: The most challenging aspects of these biomedical applications include the design of the nanoparticle form of piezoelectric materials, optimization of the piezocatalytic condition, and understanding of triggered bioeffects as discussed by the authors .
Abstract: Piezoelectric materials can convert ultrasound-based mechanical energy into electrical energy and associated electrochemical reactions, and they have attracted a wide range of applications in energy harvesting, wastewater treatment, and catalysis. In biomedical science, these piezoelectric materials have been used in ultrasound-based therapy and sonodynamic therapy. In particular, the noninvasive nature and high tissue-penetrating ability of ultrasound offer various wireless therapies at remote areas that include generation of reactive oxygen species at the intra/extracellular space, electrical stimulation of cell/brain/tissue, tumor ablation, and antibacterial activity. The most challenging aspects of these biomedical applications include the design of the nanoparticle form of piezoelectric materials, optimization of the piezocatalytic condition, and understanding of triggered bioeffects. This Spotlight on Applications will focus on recent advances on piezoelectric nanomaterial-based wireless therapy. At first we discuss the piezoelectric materials and nanoparticles, the principle of ultrasound-based piezoelectric response, and piezocatalytic reactions at their surface. Next, we discuss the approaches in constructing different piezoelectric nanoplatforms for wireless therapies. Finally, we summarize the reported wireless therapeutic approaches toward neuronal cell stimulation, combating neurodegenerative disease, antibacterial effect and fouling treatment, cancer cell and tumor therapy, regenerative medicine and tissue engineering, and health monitoring. Current challenges and future directions are discussed for further expansion of the field.
3 citations
TL;DR: Hemin is a protoporphyrin complex of ferric iron ion that acts as catalyst for hydrogen peroxide degradation in catalase and peroxidase enzymes, but poor water solubility and hemin dimerization inhibits this activity.
Abstract: Hemin is a protoporphyrin complex of ferric iron ion that acts as catalyst for hydrogen peroxide degradation in catalase and peroxidase enzymes. However, poor water solubility and hemin dimerization inhibits...
1 citations
TL;DR: In this paper , the authors showed that molecular drugs can be transformed into nanodrugs for better subcellular targeting with the enhanced therapeutic performance, which can be achieved via appropriate size and surface chemistry of colloidal nano-drugs to control or bypass the endocytic uptake and intracellular trafficking processes.
Abstract: Although the origin of disease and drug targets are primarily at intracellular space, such targeting is not achievable in currently available drugs. We and others recently show that molecular drugs can be transformed into nanodrug for better subcellular targeting with the enhanced therapeutic performance. This can be achieved via appropriate size and surface chemistry of colloidal nanodrug to control or bypass the endocytic uptake and intracellular trafficking processes. This approach can be adapted for enhanced drug performance with lower side effects.
01 Jan 2022