Biomass-derived isosorbide-based thermoresponsive hydrogel for drug delivery

Developing Supramolecular Metallogel Derived from Pd2L4 Cage Molecule for Delivering an Anti-Cancer Drug to Melanoma Cell B16-F10

Supramolecular gels are an important class of materials that are promising for its wide range of applications including drug delivery. While supramolecular gels are intrinsically porous because of the 3D nano-matrix (gel matrix) that is being formed due to supramolecular self-assembly process involving the gelator molecules during gelation, additional nanopores can be introduced to the overall gel if the gelator molecule itself holds molecular cavity such as metal-organic-cage (MOC) molecules. A MOC having the molecular formula [(Pd2L24).4NO3].3H2O.2DMF.MeOH (Pd-cage) (L2=5-Azido-N,N'-di-pyridin-3-yl-isophthalamide) was successfully synthesized and characterized by FT-IR, 1H NMR, ESI-MS and single crystal X-ray diffraction. Stimuli-reversible supramolecular metallogel PdG could easily be formed from Pd-cage in DMSO/water mixture. The molecular cage of Pd-cage was demonstrated to be available for loading an anti-cancer drug namely doxorubicin (DOX). Subsequently, DOX was also loaded within PdG and delivered to melanoma cell line B16-F10 displaying significant anti-cancer activity as revealed by both MTT and scratch assay. Rheoreversibility of PdG and its ability to load and deliver DOX to cancer cells clearly raised hope for developing this metallogel further as topical anticancer gel.

Isosorbide, a versatile green chemical: Elucidating its ADME properties for safe use

Isosorbide, an environmentally friendly and renewable substance, finds extensive application in diverse fields, such as a bisphenol A substitute, polymers, functional materials, organic solvents, fuels, and pharmaceuticals. Despite its increasing interest and widespread usage, there remains a notable absence of available reports regarding its absorption, distribution, metabolism, and excretion (ADME) properties. This study endeavors to investigate the ADME characteristics of isosorbide in rats. Isosorbide levels in biological samples were quantified based on the analytical method using gas chromatography-mass spectrometry (GC-MS). Following administration, isosorbide exhibited rapid absorption and elimination, with a bioavailability of 96.1%. The metabolic stability assay indicated that isosorbide remained stable during metabolism. The majority of absorbed isosorbide was promptly excreted, with urinary excretion as the primary route. This study furnishes valuable insights into the ADME of isosorbide, contributing to its safety assessment and fostering its continued application across various domains.

Antibacterial Hydrogel as a Self-Drug-Delivery System Derived from Zn(II)-bis-imidazole/NSAID-Based Organic-Inorganic Hybrids

A skin wound is prone to bacterial infection and growth. An antibacterial topical hydrogel that can act as a self-drug-delivery (SDD) system is reported here. Two bidentate ligands (L2/L1) derived from imidazole/benzimidazole derivatives when reacted with Zn(NO3)2 and a series of nonsteroidal-anti-inflammatory drugs (NSAIDs) produced crystalline products, which were characterized by single-crystal X-ray diffraction (SXRD). Simple mixing of the ingredients of the crystalline products (stoichiometry guided by the corresponding crystal structure) produced an aqueous gel (DMSO/water) when the bidentate ligand was water-insoluble L2, whereas water-soluble L1 readily produced hydrogels under similar conditions. Dynamic rheology and scanning electron microscopy (SEM) were employed to characterize the gels. Zone inhibition diameters, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and hemolysis data suggested that among the hydrogelators, L1MEC derived from L1, meclofenac and Zn(NO3)2, was found to be the best against the Gram-negative bacteria Escherichia coli. The corresponding hydrogel L1MEC_HG and a piece of a dried cloth bandage coated with the hydrogel also showed appreciable activity against E. coli. The antibacterial property of L1MEC_HG against E. coli, thus demonstrated, is relevant in developing an antibacterial SDD system because E. coli is reported to be present in infected wounds.

An injectable supramolecular hydrogel as a self-drug-delivery system for local chemoimmunotherapy against melanoma

Skin-cancer melanoma caused 57k death in 2020. Some of the available therapies are: topical application of a gel loaded with an anti-skin cancer drug and intravenous injection of immune cytokines; however, both the approaches have drawbacks such as inefficient internalization of the drug in cancer cells and a short half-life with severe side effects, respectively. Interestingly, we observed for the first time that a subcutaneously implanted hydrogel designed and synthesized by coordinating NSAIDs and 5-AP with Zn(II) can effectively combat melanoma cell (B16-F10)-induced tumors in C57BL/6 mice. Both in vitro and in vivo results show that it can effectively reduce PGE2 expression, consequently upregulating IFN-γ and IL-12 that eventually engage M1-macrophages for activating T cells (CD8+), triggering apoptosis. This unique all-in-one self-drug-delivery approach, wherein the hydrogel implant is made from the drug molecules itself providing both chemotherapy and immunotherapy in combating deadly melanoma, highlights the supramolecular chemistry-based bottom-up approach in cancer therapy.

Recent updates in click and computational chemistry for drug discovery and development

Drug discovery is a costly and time-consuming process with a very high failure rate. Recently, click chemistry and computer-aided drug design (CADD) represent popular areas for new drug development. Herein, we summarized the recent updates in click and computational chemistry for drug discovery and development including clicking to effectively synthesize druggable candidates, synthesis and modification of natural products, targeted delivery systems, and computer-aided drug discovery for target identification, seeking out and optimizing lead compounds, ADMET prediction as well as compounds synthesis, hopefully, inspires new ideas for novel drug development in the future.