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Background: Cancer is the major public health problem in developing countries. The treatment of cancer requires a multimodal approach and chemotherapy is one of them. Chemotherapeutic drug is administered to cancer patients in the form of a formulation which is prepared by mixing an active ingredient (drug) with the excipient. The role of excipient in a formulation is to regulate the release, bio-distribution, and selectivity of drug within the body. Methods: In this context, selectivity of an anticancer formulation is achieved through two mechanisms like passive and active targeting. The passive targeting of a formulation is generally through enhanced permeation retention (EPR) effect which is dictated by physical properties of the carrier such as shape and size. On the contrary, active targeting means surface functionalization of excipient with target-specific ligands and/or receptors to increase its selectivity. Results: Over the past several decades, remarkable progress has been made in the development and application of an engineered excipient or carrier to treat cancer more effectively. Especially nanoparticulate systems composed of metal/liposomes/polymeric material/proteins have received significant attention in the rational design of anticancer drug formulations; for example, therapeutic agents have been integrated with nanoparticles of optimal sizes, shapes and surface properties to improve their solubility, circulation half-life, and bio-distribution. In this review article, recent literature is included to discuss the role of physicochemical properties of excipients in achieving tumour targeting through passive and active approaches. Conclusion: The selection of an excipient/carrier and targeting ligand plays a very important role in rational design and development of anticancer drug formulations.

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Hispolon (HS), a bioactive polyphenol, and its derivatives such as hispolon monomethyl ether (HME), hispolon pyrazole (HP), and hispolon monomethyl ether pyrazole (HMEP) were evaluated for comparative toxicity and antigenotoxic effects. The stability of HS derivatives in biological matrices followed the order HS < HP ≈ HME < HMEP. The cytotoxicity analysis of HS derivatives indicated that HP and HMEP were less toxic than HS and HME, respectively, in both normal and tumor cell types. The mechanisms of toxicity of HS and HME involved inhibition of thioredoxin reductase (TrxR) and/or induction of reductive stress. From the enzyme kinetic and docking studies, it was established that HS and HME interacted with the NADPH-binding domain of TrxR through electrostatic and hydrophobic bonds, resulting in inhibition of the catalytic activity. Subsequently, treatment with HS, HP, and HMEP at a nontoxic concentration of 10 μM in Chinese Hamster Ovary (CHO) cells showed significant protection against radiation (4 Gy)-induced DNA damage as assessed by micronuclei and γ-H2AX assays. In conclusion, the above results suggested the importance of phenolic and diketo groups in controlling the stability and toxicity of HS derivatives. The pyrazole derivatives, HP and HMEP, may gain significance in the development of functional foods.

Herein, we report an electron beam mediated one-pot, rapid approach for the synthesis of blue light emitting organosilicon oxide nanoparticles (OSiNPs) in aqueous solution with a potential for scale-up production. Mechanistic studies based on pulse radiolysis revealed that unlike the generally believed solvated electron (e sol − ) driven process, the present synthesis proceeds through the reaction of hydroxyl radical (•OH) with the precursor molecules resulting in the formation of silane-derived radicals. Subsequently, these radicals react with each other to form OSiNPs. Compositional studies by XPS, FTIR, and Raman indicate the presence of siloxane/silicone and silica (SiO 2 ) like units as the major constituents in the NPs. XRD pattern signifies the amorphous nature of the NPs, while imaging studies revealed self-assembling of NPs (3−5 nm) into a porous structure. Notably, the NPs exhibited excitation-wavelength-dependent photoluminescence (PL) spectra, pointing to the presence of multiple emission centers with varying energy levels. The nature of these emission centers and their heterogeneous distribution was analyzed in detail through pH and absorbed dose dependent PL studies, HF treatment, fluorescence excitation spectrum, temperature dependent steady state, and time-resolved PL studies. Moreover, OSiNPs were functionalized with a biocompatible ligand, i.e., Lglutathione (L-Glu), which significantly enhanced the quantum efficiency (up to ∼25%) of emission as well as colloidal stability. These functionalized NPs (L-Glu@OSiNPs) were found to exhibit less toxicity up to a concentration of ∼0.5 mg/mL. Interestingly, the L-Glu@OSiNPs exhibited tumor selectivity (in A549 human lung cancer cells) at lower pH along with cell labeling capabilities with propensity to localize at the nucleus. Furthermore, in addition to their usage in anticounterfeiting measures, application of L-Glu@OSiNPs in fingerprinting was also demonstrated by testing on a variety of surfaces. Meanwhile, linear and reproducible PL intensity variations of OSiNPs signify highly sensitive and robust thermosensing properties of OSiNPs.

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This study demonstrates the cytotoxic activity and the underlying mechanisms of a synthetic organoselenium compound containing pyridine and diselenide moieties.