Three curcumin analogues viz., bisdemethoxy curcumin, monodemethoxy curcumin, and dimethoxycurcumin that differ at the phenolic substitution were synthesized. These compounds have been subjected for free radical reactions with DPPH radicals, superoxide radicals (O₂^•−), singlet oxygen (¹O₂) and peroxyl radicals (CCl₃O₂^•) and the bimolecular rate constants were determined. The DPPH radical reactions were followed by stopped-flow spectrometer, ¹O₂ reactions by transient luminescence spectrometer, and CCl₃O₂^• reactions using pulse radiolysis technique. The rate constants indicate that the presence of o-methoxy phenolic OH increases its reactivity with DPPH and CCl₃O₂^•, while for molecules lacking phenolic OH, this reaction is very sluggish. Reaction of O₂^•− and ¹O₂ with curcumin analogues takes place preferably at β-diketone moiety. The studies thus suggested that both phenolic OH and the β-diketone moiety of curcumin are involved in neutralizing the free radicals and their relative scavenging ability depends on the nature of the free radicals.

One of the major challenges in harnessing the therapeutic benefits of curcumin (an active ingredient from turmeric) is its poor bioavailability due to its short biological half-life. In this regard, nanoformulations have shown tremendous hope for improving the pharmacokinetic and therapeutic behavior of curcumin by altering its biological stability and bioavailability. Biopolymers, especially alginate and chitosan, have received special attention as excipients to prepare nanoformulations of curcumin due to their abundant availability, biocompatibility, and amicability to form different types of self-assembled structures and ease of undergoing chemical modifications. However, there are certain challenges, such as poor water solubility under physiological conditions and heterogeneity with regard to molecular weight and large-scale production of well-preserved nanostructures. Substantial advancement has been achieved towards overcoming these challenges by developing newer derivatives through a chemical modifications approach, and this has ascertained the suitability of alginate and chitosan as excipients for drug delivery systems (DDS). The present minireview briefly discusses curcumin and its limitation as a drug molecule, carbohydrates as DDS, and the recent developments related to the alginate and chitosan-based nanoformulations of curcumin. Special emphasis has been given to highlighting the impact of alginate and chitosan-based nanoformulations in improving the therapeutic efficacy and bioavailability of curcumin.

In addition to their classical role in ATP generation, mitochondria also contribute to Ca²⁺ buffering, free radical production, and initiation of programmed cell death. Mitochondrial dysfunction has been linked to several leading causes of morbidity and mortality worldwide including neurodegenerative, metabolic, and cardiovascular diseases as well as several cancer subtypes. Thus, there is growing interest in developing drug-delivery vehicles capable of shuttling therapeutics directly to the mitochondria. Here, we functionalized the conventional 10,12-pentacosadiynoic acid/1,2-dimyristoyl-sn-glycero-3-phosphocholine (PCDA/DMPC)-based liposome with a mitochondria-targeting triphenylphosphonium (TPP) cationic group. A fluorescent dansyl dye (DAN) group was also included for tracking mitochondrial drug uptake. The resultant PCDA-TPP and PCDA-DAN conjugates were incorporated into a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)-based lipid bilayer, and these modified liposomes (Lip-DT) were studied for their cellular toxicity, mitochondrial targeting ability, and efficacy in delivering the drug Doxorubicin (Dox) to human colorectal carcinoma (HCT116) and human breast (MCF7) cancer cells in vitro. This Lip-DT-Dox exhibited the ability to shuttle the encapsulated drug to the mitochondria of cancer cells and triggered oxidative stress, mitochondrial dysfunction, and apoptosis. The ability of Lip-DT-Dox to trigger cellular toxicity in both HCT116 and MCF7 cancer cells was comparable to the known cell-killing actions of the unencapsulated drug (Dox). The findings in this study reveal a promising approach where conventional liposome-based drug delivery systems can be rendered mitochondria-specific by incorporating well-known mitochondriotropic moieties onto the surface of the liposome.

The dual role of cucurbituril-functionalized Co:Ni alloy nanocomposites is demonstrated: one for the sustained release of NH ₃ -free green H ₂ through the hydrolysis of ammonia borane and other as an efficient electrocatalyst for the hydrogen evolution reaction.