Covalently bonded
Eudragit S-100 (EU) and chitosan (CS) based colon-specific
nanoparticles (CSE NPs) were fabricated as drug carriers for treating
colorectal cancers through oral administration. Thiolation of EU and
CS prevents the usage of the cross-linking agent. This gives an advantage
over the shortcomings of existing EU- and CS-based delivery systems
that are associated with large sized nanoparticles with a broad range
of size distribution. Paclitaxel (PTX)-loaded CSE NPs presented an
efficacy of 8–10% after 48 h of treatment on the HCT 116 cell
line signifying uniform distribution of drug inside the cells. About
66% accumulation of cell population was observed in G2/M phase for
PTX-loaded CSE NPs, indicating arrest of cell division during the
mitotic phase. Biodistribution studies on male Balb/C mice demonstrated
retention of CSE NPs in the colon region up to 24 h post oral administration.
These findings confer a convenient and effective way for preparing
CS- and EU-based drug delivery systems with sustained release and
target specificity for colorectal cancers.
Acute myeloid leukemia (AML) is a malignant disorder of hematopoietic progenitor cells with a poor prognosis of 26% of patients surviving 5 years after diagnosis. Poor bioavailability and solubility are significant factors limiting the efficacy of chemopreventive agents. In AML, the epigenetic regulator polycomb group of protein member EZH2 is highly expressed and is essential for the survival of leukemic cells. An EZH2-specific inhibitor, EPZ011989, encapsulated in human serum albumin nanoparticles (HSANPs) was synthesized for the first time via the desolvation method. The noncovalent interactions between EPZ011989 and HSANPs in nanocomposites facilitating the efficient loading and sustainable release of the drug showed enhanced cellular uptake and nuclear localization of EPZ011989-loaded HSANPs in human AML cell lines. The reduction of cell viability, colony formation inhibition, cell cycle arrest at the G2/M phase, and cell proliferation assay promoting apoptosis through the loss of mitochondrial homeostasis exerting antileukemic activity were evident. The real-time polymerase chain reaction (PCR) and western blot-based studies showed that the present nanoformulation reduces the level of PcG proteins, including EZH2, BMI-1, etc. This downregulation is associated with reduced H3K27me3 and H2AK119ub modifications conferring chromatin compaction. The immunoprecipitation study showed the physical interaction of EZH2 and c-Myb can be linked to the regulation of leukemogenesis. Further investigation revealed the mechanism of EZH2 and c-Myb downregulation via ubiquitination and proteasomal degradation pathway, confirmed by using proteasome inhibitor, suggesting the key role of proteasomal degradation machinery. Moreover, c-Myb interacted with the EZH2 promoter, which is evident by the chromatin immunoprecipitation assay and siRNA silencing. Furthermore, the formulation of EPZ011989 in HSANPs improved its biodistribution in vivo and showed excellent aqueous dispersibility and biocompatibility. In vivo studies further showed that EPZ011989-loaded HSANPs reduce the expression of CD11b + and CD45 + markers in immunophenotyping from peripheral blood and bone marrow in engrafted nude mice. Targeted depletion of EZH2 alleviated the disease progression in nude mice and prolonged their survival. The findings provide valuable experimental evidence for the targeted epigenetic therapy of AML. The present results demonstrate an epigenetic regulation-based superior antileukemic therapy.
The imbalance in the bone remodeling process with more bone resorption by osteoclasts compared to bone formation by osteoblasts results in a metabolic bone disorder known as osteoporosis. This condition reduces the bone mineral density and increases the risk of fractures due to low bone mass and disrupted bone microarchitecture. Osteoclastogenesis increases when the receptor activator NFκB ligand (RANKL) on the osteoblast surface binds to the receptor activator NFκB (RANK) on the osteoclast surface and the function of the decoy receptor of RANKL, osteoprotegrin, is compromised due to external stimuli such as heparin and lipopolysaccharides. The RANK/RANKL axis promotes the nuclear factor kappa B (NFκB) expression, which in turn increases the histone methyltransferase activity of EzH2 and EzH1 for the epigenetic regulation of osteoclastogenesis-related genes. Genistein counteracts NFκB-induced osteoclastogenesis and downstream signaling through the direct regulation of histone methyltransferase, EzH2 and EzH1, transcription. However, genistein possesses limitations like low bioavailability, low water solubility, high estrogen activity, and thyroid side effects, which obstruct its therapeutic usage. Here, the nanoemulsified formulation of genistein with vitamin D was utilized to circumvent the limitations of genistein so that it can be utilized for therapeutic purposes in osteoporosis management. The nanoemulsification of genistein and vitamin D was performed through the spontaneous emulsification using Tween 80 and medium chain triglyceride oil as an organic phase. The physiologically stable and biocompatible combination of the genistein and vitamin D nanoemulsion (GVNE) exhibited the controlled release pattern of genistein with Korsmeyer−Peppas and Higuchi models under different pH conditions (7.4, 6.5, and 1.2). The GVNE potentially enhanced the therapeutic efficacy under in vitro osteoporosis models and helped restore disease parameters like alkaline phosphatase activity, tartrate-resistant acid phosphatase activity, and the formation of multinuclear giant cells. Molecularly, the GVNE overturned the LPS-induced osteoclastogenesis by downregulation of NFκB expression along with its binding on EzH2 and EzH1 promoters. GVNE effects on the osteoporosis model established it as an efficient antiosteoporotic therapy. This nanonutraceutical-based formulation provides an epigenetic regulation of osteoporosis management and opens new avenues for alternate epigenetic therapies for osteoporosis.
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