Silver nanoparticles act as antitumor agents because of their antiproliferative and apoptosis-inducing properties. The present study aims to develop silver nanoparticle-loaded liposomes for the effective management of cancer. Silver nanoparticle-encapsulated liposomes were prepared using the thin-film hydration method coupled with sonication. The prepared liposomes were characterized by DLS (Dynamic Light Scattering analysis), FESEM (Field Emission Scanning Electron Microscope), and FTIR (Fourier Transform Infrared spectroscopy). The in vitro drug release profile of the silver nanoparticle-loaded liposomes was carried out using the dialysis bag method and the drug release profile was validated using various mathematical models. A high encapsulation efficiency of silver nanoparticle-loaded liposome was observed (82.25%). A particle size and polydispersity index of 172.1 nm and 0.381, respectively, and the zeta potential of −21.5 mV were recorded. FESEM analysis revealed spherical-shaped nanoparticles in the size range of 80–97 nm. The in vitro drug release profile of the silver nanoparticle-loaded liposomes was carried out using the dialysis bag method in three different pHs: pH 5.5, pH 6.8, and pH 7.4. A high silver nanoparticle release was observed in pH 5.5 which corresponds to the mature endosomes of tumor cells; 73.32 ± 0.68% nanoparticle was released at 72 h in pH 5.5. Among the various mathematical models analyzed, the Higuchi model was the best-fitted model as there is the highest value of the correlation coefficient which confirms that the drug release follows the diffusion-controlled process. From the Korsmeyer–Peppas model, it was confirmed that the drug release is based on anomalous non-Fickian diffusion. The results indicate that the silver nanoparticle-loaded liposomes can be used as an efficient drug delivery carrier to target cancer cells of various types.
27 December 2023 in Journal of Biomolecular Structure and Dynamics
Leukemia is a haematological malignancy affecting blood and bone marrow, ranking 10th among the other common cancers. DNA methylation is an epigenetic dysregulation that plays a critical role in leukemogenesis. DNA methyltransferases (DNMTs) such as DNMT1, DNMT3A and DNMT3B are the key enzymes catalysing DNA methylation. Inhibition of DNMT1 with secondary metabolites from medicinal plants helps reverse DNA methylation. The present study focuses on inhibiting DNMT1 protein (PDB ID: 3PTA) with annonaceous acetogenins through in-silico studies. The docking and molecular dynamic (MD) simulation study was carried out using Schrödinger Maestro and Desmond, respectively. These compounds' drug likeliness, ADMET properties and bioactivity scores were analysed. About 76 different acetogenins were chosen for this study, among which 17 showed the highest binding energy in the range of -8.312 to -10.266 kcal/mol. The compounds with the highest negative binding energy were found to be annohexocin (-10.266 kcal/mol), isoannonacinone (-10.209 kcal/mol) and annonacin (-9.839 kcal/mol). MD simulation results reveal that annonacin remains stable throughout the simulation time of 100 ns and also binds to the catalytic domain of DNMT1 protein. From the above results, it can be concluded that annonacin has the potential to inhibit the DNA methylation process and prevent leukemogenesis.Communicated by Ramaswamy H. Sarma.
Epigenetic regulation plays a pivotal role in the aging process, influencing how genes are expressed without altering the underlying DNA sequence. Aging is associated with characteristic changes in epigenetic markers, including DNA methylation, histone modifications, and chromatin remodeling, which collectively impact gene expression, genomic stability, and cellular function. These alterations contribute to the progressive decline in tissue homeostasis and the development of age-related diseases. Recent research has identified epigenetic clocks — biomarkers based on DNA methylation patterns — that can accurately predict biological age and highlight the reversible nature of some aging processes. Understanding how epigenetic mechanisms drive aging offers promising opportunities for therapeutic interventions aimed at slowing aging, restoring tissue function, and extending healthy lifespan.
Aging is a natural and progressive biological process influenced by a combination of genetic, molecular, and environmental factors. The primary causes of aging include cellular and molecular damage accumulated over time, genomic instability, telomere shortening, epigenetic alterations, and oxidative stress. Additionally, dysfunctions in mitochondria, impaired protein maintenance (proteostasis), chronic low-grade inflammation, and the exhaustion of stem cells contribute significantly to the decline in physiological functions. Both intrinsic mechanisms, such as programmed cellular responses, and extrinsic factors, like lifestyle choices and environmental exposures, interplay to drive the aging process. Understanding the underlying causes of aging is crucial for developing interventions aimed at extending healthy lifespan and preventing age-related diseases.