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This book describes the theories, applications, and challenges for different oral controlled release formulations.This book differs from most in its focus on oral controlled release formulation design and process development.

This research describes the development and thorough characterization of a novel, versatile, and biocompatible hybrid nanocarrier of the NO-releasing agent NOC-18, with a specific focus on optimizing the purification process. In this study, we focused on the sustained release of NO using biocompatible and diagnostic hybrid magnetic nanoparticles (hMNPs) containing cerium-doped maghemite (CM) NPs, embedded within human serum albumin (HSA) protein. A comprehensive study was conducted using electron paramagnetic resonance (EPR) alongside the Griess assay to evaluate NO release from the chosen NO donor, NOC-18, and to assess the limitations of the molecule under various reaction conditions, identifying the optimal conditions for binding NOC-18 with minimal NO loss. Two types of particles were designed: In-hMNPs, where NOC-18 is encapsulated within the particles, and Out-hMNPs, where NOC-18 is attached onto the surface. Our results demonstrated that In-hMNPs provided a sustained and prolonged release of NO (half-life, 50 h) compared to the rapid release for the Out-hMNPs, likely due to the strong bonds formed with cerium, which helped to stabilize the NO molecules. These results represent a promising approach to designing a dual-function agent that combines contrast properties for tumor MRI with the possibility of increasing the permeability of tumor vasculature. The employment of this dual-function agent in combination with nanotherapeutics could improve the latter’s efficacy by facilitating their access to the tumor.

Melatonin regulates vital physiological processes in animals, such as the circadian cycle, sleep, locomotion, body temperature, food intake, and sexual and immune responses. In plants, melatonin modulates seed germination, longevity, circadian cycle, photoperiodicity, flowering, leaf senescence, postharvest fruit storage, and resistance against biotic and abiotic stresses. In plants, the effect of melatonin is mediated by various regulatory elements of the redox network, including RNS and ROS. Similarly, the radical gas NO mediates various physiological processes, like seed germination, flowering, leaf senescence, and stress responses. The biosynthesis of both melatonin and NO takes place in mitochondria and chloroplasts. Hence, both melatonin and nitric oxide are key signaling molecules governing their biological pathways independently. However, there are instances when these pathways cross each other and the two molecules interact with each other, resulting in the formation of N-nitrosomelatonin or NOMela, which is a nitrosated form of melatonin, discovered recently and with promising roles in plant development. The interaction between NO and melatonin is highly complex, and, although a handful of studies reporting these interactions have been published, the exact molecular mechanisms governing them and the prospects of NOMela as a NO donor have just started to be unraveled. Here, we review NO and melatonin production as well as RNS–melatonin interaction under normal and stressful conditions. Furthermore, for the first time, we provide highly sensitive, ozone-chemiluminescence-based comparative measurements of the nitric oxide content, as well as NO-release kinetics between NOMela and the commonly used NO donors CySNO and GSNO.

Nitric oxide (NO) is a key molecule in cardiovascular homeostasis and its abnormal delivery is highly associated with the occurrence and development of cardiovascular disease (CVD). The assessment and manipulation of NO delivery is crucial to the diagnosis and therapy of CVD, such as endothelial dysfunction, atherosclerotic progression, pulmonary hypertension, and cardiovascular manifestations of coronavirus (COVID-19). However, due to the low concentration and fast reaction characteristics of NO in the cardiovascular system, clinical applications centered on NO delivery are challenging. In this tutorial review, we first summarized the methods to estimate the in vivo NO delivery process, based on computational modeling and flow-mediated dilation, to assess endothelial function and vulnerability of atherosclerotic plaque. Then, emerging bioimaging technologies that have the potential to experimentally measure arterial NO concentration were discussed, including Raman spectroscopy and electrochemical sensors. In addition to diagnostic methods, therapies aimed at controlling NO delivery to regulate CVD were reviewed, including the NO release platform to treat endothelial dysfunction and atherosclerosis and inhaled NO therapy to treat pulmonary hypertension and COVID-19. Two potential methods to improve the effectiveness of existing NO therapy were also discussed, including the combination of NO release platform and computational modeling, and stem cell therapy, which currently remains at the laboratory stage but has clinical potential for the treatment of CVD.

Environmental pollutants like heavy metals are toxic, persistent, and bioaccumulative in nature. Contamination of agricultural fields with heavy metals not only hampers the quality and yield of crops but also poses a serious threat to human health by entering the food chain. Plants generally cope with heavy metal stress by regulating their redox machinery. In this context, nitric oxide (NO) plays a potent role in combating heavy metal toxicity in plants. Studies have shown that the exogenous application of NO donors protects plants against the deleterious effects of heavy metals by enhancing their antioxidative defense system. Most of the studies have used sodium nitroprusside (SNP) as a NO donor for combating heavy metal stress despite the associated concerns related to cyanide release. Recently, NO-releasing nanoparticles have been tested for their efficacy in a few plants and other biomedical research applications suggesting their use as an alternative to chemical NO donors with the advantage of safe, slow and prolonged release of NO. This suggests that they may also serve as potential candidates in mitigating heavy metal stress in plants. Therefore, this review presents the role of NO, the application of chemical NO donors, potential advantages of NO-releasing nanoparticles, and other NO-release strategies in biomedical research that may be useful in mitigating heavy metal stress in plants.

A chemical study of Aesculus wilsonii Rehd. (also called Suo Luo Zi) and the in vitro anti-inflammatory effects of the obtained compounds was conducted. Retrieving results through SciFinder showed that there were four unreported compounds, aeswilosides I–IV (1–4), along with fourteen known isolates (5–18). Their structures were elucidated by extensive spectroscopic methods such as UV, IR, NMR, [α]D, and MS spectra, as well as acid hydrolysis. Among the known ones, compounds 5, 6, 8–10, and 12–16 were obtained from the Aesculus genus for the first time; compounds 7, 11, 17, and 18 were first identified from this plant. The NMR data of 5 and 18 were reported first. The effects of 1–18 on the release of nitric oxide (NO) from lipopolysaccharide (LPS)-induced RAW264.7 cells were determined. The results showed that at concentrations of 10, 25, and 50 μM, the novel compounds, aeswilosides I (1) and IV (4), along with the known ones, 1-(2-methylbutyryl)phloroglucinyl-glucopyranoside (10) and pisuminic acid (15), displayed significant inhibitory effects on NO production in a concentration-dependent manner. It is worth mentioning that compound 10 showed the best NO inhibitory effect with a relative NO production of 88.1%, which was close to that of the positive drug dexamethasone. The Elisa experiment suggested that compounds 1, 4, 10, and 15 suppressed the release of TNF-α and IL-1β as well. In conclusion, this study enriches the spectra of compounds with potential anti-inflammatory effects in A. wilsonii and provides new references for the discovery of anti-inflammatory lead compounds, but further mechanistic research is still needed.

Cembrane-type diterpenoids are among the most frequently encountered natural products from the soft corals of the genus Lobophytum. In the course of our investigation to identify anti-inflammatory constituents from a wild-type soft coral Lobophytum crassum, two new cembranoids, lobophyolide A (1) and B (2), along with five known compounds (3–7), were isolated. The structures of these natural products were identified using NMR and MS spectroscopic analyses. Compound 1 was found to possess the first identified α-epoxylactone group among all cembrane-type diterpenoids. The in vitro anti-inflammatory effect of compounds 1–5 was evaluated. The results showed that compounds 1–5 not only reduced IL-12 release, but also attenuated NO production in LPS-activated dendritic cells. Our data indicated that the isolated series of cembrane-type diterpenoids demonstrated interesting structural features and anti-inflammatory activity which could be further developed into therapeutic entities.

Nitric esters are among the compounds that can liberate nitrogen monoxide (NO) in the organism. Due to the vasodilatation caused by nitrogen monoxide, NO-donors have been shown to protect endothelial function, acting as vasodilators, promoting efficient oxygen supply to tissues, to lower blood pressure, and to inhibit platelet aggregation. Incorporation of a NO-liberating moiety in the structure of non-steroidal anti-inflammatory drugs results in anti-inflammatory agents that are safer for the gastrointestinal system. In this research, ibuprofen and naproxen, two commonly applied non-steroidal anti-inflammatory drugs (NSAID), non-selective inhibitors of cyclooxygenases, were used to design novel anti-inflammatory agents able to release NO in the organism. Thus, the NSAIDs were amidated with beta-alanine and L-proline, which were able to incorporate the 2-nitro-oxyethyl moiety as the NO donor. The resulting compounds were anti-inflammatory agents, found to be more potent than the mother drugs, demonstrating remarkable inhibition of cyclooxygenase-2 over cyclooxygenase-1 and the ability to release NO in vitro. Furthermore, two of the most active anti-inflammatory compounds proved to be effective hypolipidemic agents, decreasing plasma total cholesterol, triglycerides, and LDL-cholesterol in hyperlipidemic rats significantly. The most effective compound in all the above tests was the ibuprofen derivative 5, which inhibited COX-2 by 95%, decreased inflammation by 73%, and reduced all lipidemic indices by more than 50%. Furthermore, docking experiments of compound 5 on the active sites of COX-1 and COX-2 showed that it interacts intensely with the binding site of COX-2, and the binding energy is equivalent to that of the relevant to celecoxib selective COX-2 inhibitor 4-[5-(4-bromophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl] benzenesulfonamide (SC-5580). In conclusion, the performed structural modifications resulted not only in the improvement of the anti-inflammatory activity, compared with the parent NSAID, but also acquired strong hypolipidemic activity. Thus, the combination of structural characteristics resulting in a decrease in lipidemia, with possible inhibition of atherosclerosis, due to their anti-inflammatory activity and vasodilatation ability, via the liberated NO, may constitute a useful rationale for new compounds.

Gaseous therapy based on nitric oxide (NO), as a potential anti-tumor treatment strategy, has attracted great attention, but the targeted and controlled gas release in the tumor site still remains a challenge. In addressing these difficulties, a near-infrared (NIR) light-triggered NO release nanogenerator with a “linkage mechanism” was designed on the basis of sodium nitroprusside-doped mesoporous Prussian blue nanoparticles, in which the outer structure was modified with pH-sensitive gatekeeper chitosan and tumor-targeting agent folic acid. The “linkage mechanism” can achieve precise release of NO under the control of photothermal effect at tumor site, which can couple photothermal therapy and gas therapy to address the premature release of gas during transportation. Meanwhile, the amount of released gas can be controlled by adjusting the irradiation time and laser intensity. Furthermore, as-fabricated nanocomposites hold high photothermal conversion efficiency under NIR laser irradiation, resulting in the on-demand release of NO and chemotherapy drugs. The released NO can inhibit the expression of hypoxia-inducible factor α (HIF-1α) and alleviate the hypoxic tumor microenvironment, thereby enhancing the efficacy of chemotherapy. Moreover, in vitro and in vivo experiments exhibited remarkable antitumor efficiency, and the synergistic gas/chemo/photothermal therapy of deep tumors was achieved. These findings indicate an effective strategy to stimulate further the development of deep tumor therapy, which may provide new insights into other NO-related medical applications.

In order to establish an efficient method for separation of polymethoxyflavones (PMFs) and explore the anti-inflammatory mechanism of PMF monomers, a citrus variety rich in PMFs, Ougan (Citrus reticulata cv. Suavissima), was selected, and three monomers, including nobiletin, tangeretin, and 5-demethylnobiletin, were purified by ultrasonic-assisted extraction, solid phase extraction, and high-speed countercurrent chromatography separation. UPLC-MS was used to identify the three monomers. UPLC determined purities of 99.87% to nobiletin, 99.76% to tangeretin, and 98.75% to 5-demethylnobiletin with the standard curve method. A lipopolysaccharide (LPS)-induced NO releasing model was performed in the mouse microglia BV-2 cell line. Results illustrated that PMF monomers inhibited the NO release and the inflammation-related cytokines, including IL-1β, IL-6, and TNFα elevation. QRT-PCR revealed that PMFs alleviated LPS-induced upregulation of iNOS, IL-6, JAK2, TNFα, IL-1β, and NF-κB and LPS-induced downregulation of IκBα, while they did not affect TLR1, TLR2, TLR4, and TLR6. STAT3 expression was repressed by tangeretin and 5-demethylnobiletin, but not by nobiletin. Western blot assay also showed a suppression of expression and phosphorylation of JAK2 by all three PMF monomers, while STAT3 phosphorylation was restrained by tangeretin and 5-demethylnobiletin. The mechanism was primarily verified by the JAK2 inhibitor Ruxolitinib and the STAT3 inhibitor Stattic.