Immunomodulatory and immune-toxicological role of nanoparticles: Potential therapeutic applications.

Nowadays, Nanoparticle-based immunotherapeutic research has invoked global interest due to their unique properties. The immune system is a shielding structure that defends living things from external threats. Before the use of any materials in drug design, it is essential to study the immunological response to avoid triggering undesirable immune responses in the body. This review tries to summarize the properties, various applications, and immunotherapeutic aspects of NP-induced immunomodulation relating to therapeutic development and toxicity in human health. The role of NPs in the immune system and their modulatory functions, resulting in immunosuppression or immunostimulation, exerts benefits or dangers depending on their compositions, sizes, surface chemistry, and so forth. After NPs enter into the body, they can interact with body fluid exposing, them to different body proteins to form protein corona particles and other bio-molecules (DNA, RNA, sugars, etc.), which may alter their bioactivity. Phagocytes are the first immune cells that can interact with foreign materials including nanoparticles. Immunostimulation and immunosuppression operate in two distinct manners. Overall, functionalized nanocarriers optimized various therapeutic implications by stimulating the host immune system and regulating the tranquility of the host immune system. Among others, toxicity and bio-clearance of nanomaterials are always prime concerns at the preclinical and clinical stages before final approval. The interaction of nanoparticles with immune cells causes direct cell damage via apoptosis and necroses as well as immune signaling pathways also become influenced.

Unconventional electronic phase transition in SnBi2Te4: role of anomalous thermal expansion.

We propose SnBi2Te4to be a novel topological quantum material exhibiting temperature (T) mediated transitions between rich electronic phases. Our combined theoretical and experimental results suggest that SnBi2Te4goes from a low-Tsemimetallic phase to a high-T(room temperature) insulating phase via an intermediate metallic phase. Single crystals of SnBi2Te4are characterized by various experimental probes including synchrotron based x-ray diffraction, magnetoresistance, Hall effect, Seebeck coefficient and magnetization. X-ray diffraction data confirms an anomalous thermal expansion of the unit cell volume below ∼100 K, which significantly affects the bulk band structure and hence the transport properties. Simulated surface states are found to be topologically robust with varyingT. This indirectly supports the experimentally observed paramagnetic singularity in the entireT-range. The proposed coexistence of such rich phases is a rare occurrence, yet it facilitates a fertile ground to tune them in a material driven by structural changes.

Boosting photocatalytic property of graphitic carbon nitride with metal complex fabrication for efficient degradation of organic pollutants.

The development of efficient and stable photocatalysts for degradation of refractory pollutants using minimal amounts of metal remains a major challenge. Herein, we synthesize a novel catalyst by fabrication of manganese (III) acetylacetonate complex [Mn (acac)3] over graphitic carbon nitride (GCN) denoted as 2-Mn/GCN by facile ultra-sonication method. The fabrication of the metal complex enables the migration of electrons from the conduction band of graphitic carbon nitride to Mn (acac)3, and migration of holes from valence band of Mn (acac)3 to GCN upon irradiation. Exploiting the improved surface properties, light absorption, and charge separation ensure generation of superoxide and hydroxyl radicals resulting in the rapid degradation of a variety of pollutants. The designed 2-Mn/GCN catalyst realized 99.59% rhodamine b (RhB) degradation in 55 min and 97.6% metronidazole (MTZ) degradation in 40 min with 0.7% Mn content. The influence of catalyst amount, different pH and presence of anions on the degradation kinetics was also explored to offer insights into photoactive material design.

Core-shell assembly of ZrO2 nanoparticles with ionic liquid: a novel and highly efficient heterogeneous catalysts for Biginelli and esterification reactions.

Imidazolium sulfonic acid chloride grafted ZrO2 nanoparticles (ZrO2-IL) were synthesized through facile post-treatment of the nanoparticles with the imidazolium-sulfonic acid chloride ionic liquid. The immobilization of the ionic liquid over the ZrO2 nanoparticles was evident from the XRD, SEM, TEM, Raman, BET, and XPS analysis. The results obtained from the XRD analysis clearly show that the catalyst has an orthorhombic structure and from the BET analysis it is evident that the surface is mesoporous with uniform pore sizes and pore distribution. Further evidence of immobilization of ionic liquid over the ZrO2 NPs was obtained from the SEM, TEM, XPS, and Raman analysis. Under mild conditions, the synthesized heterostructure was used in the acid-catalyzed esterification of different acids. The ZrO2-IL catalyst converts 99% of the acid to ester with a 98.9% yield in 1h. The material was also shown to be highly efficient as catalyst for the Biginelli reaction under solvent-free conditions, with the catalyst for dihydropyrimidin-2(1H)-one (DHPMs) in 1h with 99.2% conversion and 99% yield. The synergy between the ionic liquid catalyst and the substrates increased the catalytic efficiency and resulted in high-yield product conversion. The mechanism of both transformation reactions was investigated, as well as the synergy between ionic liquid and ZrO2 nanoparticles for better catalytic efficiency was established.