Melatonin delivered in solid lipid nanoparticles ameliorated its neuroprotective effects in cerebral ischemia

Melatonin hyalurosomes as a powerful antioxidant for combating skin damage induced by UV radiation

Extrinsic skin aging is caused by chronic skin photodamage. The present study aims to inspect the role of nanoencapsulation of melatonin (MEL) in hyalurosomes in combating UVB-induced skin damage to take advantage of the hydrating penetration enhancing and antiaging effects of hyaluronic acid along with the powerful antioxidant effects of MEL. Measurement of particle size, zeta potential, encapsulation efficiency and in vitro MEL release were carried out. The in vivo photoprotective effects of MEL were tested in rats. A histopathological examination was conducted, and antioxidant and anti-inflammatory markers were measured along with estimating the expression of P38 MAPK, P-ERK and P-JNK. Particle size and zeta potential of MEL hyalurosomes were 285.9 nm and -26.3 mV with 95% entrapment efficiency and provided a sustained release profile for 48h. In vivo, results revealed the superior effect of MEL hyalurosomes in protecting skin against UVB-induced damage and reducing the levels of inflammatory mediators like TNF-α and IL6 compared with MEL suspension. However, they had a prominent role in increasing the levels of antioxidants. These findings may be accredited to the effect of nanoencapsulation in enhancing skin penetration and deposition of MEL besides the effect of hyaluronic acid as a powerful antiaging tool.

Significance of the gut tract in the therapeutic mechanisms of polydopamine for acute cerebral infarction: neuro-immune interaction through the gut-brain axis

Background

Recent research has made significant progress in elucidating gastrointestinal complications following acute cerebral infarction (ACI), which includes disorders in intestinal motility and dysbiosis of the gut microbiota. Nevertheless, the role of the gut (which is acknowledged as being the largest immune organ) in the immunoreactive effects of polydopamine nanoparticles (PDA) on acute ischemic stroke remains inadequately understood. In addition to its function in nutrient absorption, the gut acts as a protective barrier against microbes. Systemic immune responses, which are triggered by the disruption of gut barrier integrity, are considered as one of the mechanisms underlying acute ischemic stroke, with the gut-brain axis (GBA) playing a pivotal role in this process.

Methods

In this study, we used a PDA intervention in an ACI model to investigate ACI-like behavior, intestinal barrier function, central and peripheral inflammation, and hippocampal neuron excitability, thus aiming to elucidate the mechanisms through which PDA improves ACI via the GBA.

Results

Our findings indicated that as ACI mice experienced dysbiosis of the gut microbiota and intestinal barrier damage, the levels of proinflammatory factors in the serum and brain significantly increased. Additionally, the activation of astrocytes in the hippocampal region and neuronal apoptosis were observed in ACI mice. Importantly, our study is the first to provide evidence demonstrating that PDA effectively suppresses the neuroimmune interactions of the gut-brain axis and significantly improves intestinal epithelial barrier integrity.

Conclusion

We hope that our discoveries will serve as a foundation for further explorations of the therapeutic mechanisms of PDA in ACI, particularly in elucidating the protective roles of gut microbiota and intestinal barrier function, as well as in the development of more targeted clinical interventions for ACI.

Revolutionizing Stroke Care: Nanotechnology-Based Brain Delivery as a Novel Paradigm for Treatment and Diagnosis

Stroke, a severe medical condition arising from abnormalities in the coagulation-fibrinolysis cycle and metabolic processes, results in brain cell impairment and injury due to blood flow obstruction within the brain. Prompt and efficient therapeutic approaches are imperative to control and preserve brain functions. Conventional stroke medications, including fibrinolytic agents, play a crucial role in facilitating reperfusion to the ischemic brain. However, their clinical efficacy is hampered by short plasma half-lives, limited brain tissue distribution attributed to the blood-brain barrier (BBB), and lack of targeted drug delivery to the ischemic region. To address these challenges, diverse nanomedicine strategies, such as vesicular systems, polymeric nanoparticles, dendrimers, exosomes, inorganic nanoparticles, and biomimetic nanoparticles, have emerged. These platforms enhance drug pharmacokinetics by facilitating targeted drug accumulation at the ischemic site. By leveraging nanocarriers, engineered drug delivery systems hold the potential to overcome challenges associated with conventional stroke medications. This comprehensive review explores the pathophysiological mechanism underlying stroke and BBB disruption in stroke. Additionally, this review investigates the utilization of nanocarriers for current therapeutic and diagnostic interventions in stroke management. By addressing these aspects, the review aims to provide insight into potential strategies for improving stroke treatment and diagnosis through a nanomedicine approach.

Paroxetine Loaded Nanostructured Lipid Carriers Based In-situ Gel for Brain Delivery via Nasal Route for Enhanced Anti-Depressant Effect: In Vitro Prospect and In Vivo Efficacy

This study focused on developing a thermosensitive gel with nanostructured lipid carriers (NLCs) loaded with paroxetine (PAR) to enhance the treatment and management of depression via nasal administration. Micro emulsion technique was utilized for the PAR-NLCs preparation. The acetyl alcohol and oleic acid were used in the ratio of 76:24. In the NLCs Tween 40, Span40 and Myrj 52 were used as a surfactant. The NLCs were then added into Poloxamer mixture to get thermosensitive NLCs based gel. Characterization, in vitro and in vivo studies were performed to check the efficiency of formulation in drug delivery. The entrapment efficiency of optimized PAR-NLCs was about 90%. The particle size, zeta potential and PDI were 155 ± 1.4 nm, -25.9 ± 0.5 mV, and 0.12 ± 0.01 respectively. The optimized gel showed a gelling temperature of 31.50 ± 0.50°C and a gelling time of 1 ± 0.12 s with a pH of 6, suitable for nasal administration. The in vitro release assay of PAR-NLC-gel showed a cumulative release of about 59% in the first 6 h after comparison with PAR-NLCs which showed almost 100%release. In vivo studies included forced swim test and tail suspension tests showed significant potential for treating depression when compared to PAR-NLCs. PAR-NLCs and NLCs based gel enhanced the tissue architecture and suppressed the expression of TNF-α in brain cortex from histological and immunohistochemical analysis. PAR- NLCs gel-based delivery system can prove to be an effective delivery system for brain targeting through nose for the better management of depression.

Fabrication of Uniform Melatonin Microparticles Potentially for Nasal Delivery: A Comparison of Spray Drying and Spray Freeze Drying

PURPOSE

Insomnia is a major health concern, and melatonin (MLT) is key for initiating sleep. Delivering MLT nasally can enhance brain bioavailability by targeting the olfactory region. This study aimed to fabricate MLT embedded microparticles for nasal delivery.

METHODS

MLT-cyclodextrin (CD) derivatives complex microparticles (MCCMPs) were fabricated by spray drying and spray freeze drying MLT and CD derivative solutions. Phase solubility and 1H-1H ROSEY NMR analysis assessed MLT-CD assembly. The effects of formulation compositions and process parameters on microparticle structural attributes were investigated. The in vitro nasal release and deposition performances were evaluated by a modified paddle-over-disk apparatus and 3D-printed nasal cavity cast, respectively.

RESULTS

Sodium sulphobutylether-β-cyclodextrin (SBE-β-CD) exhibited the best complexation ability with MLT, with the indole structure of MLT included in its cavity. Spray dried MCCMPs showed dense structure with high density, while the spray freeze dried counterpart showed the brittle and porous structure with low density. Despite the porous structure may promote the release rate of spray freeze dried samples, the high hydrophilicity of the CD derivative overshadows this advantage. Samples prepared by spray drying not only exhibited rapid release rates but also could deposit more effectively in the olfactory region, as they avoid breakage due to their higher mechanical strength. The optimal sample showed ~ 86.70% of the MLT released at 20 min and ~ 10.57% of the deposition fraction in the olfactory region.

CONCLUSIONS

This work compares MCCMPs fabricated by spray drying and spray freeze drying, providing the optimal formulation and process combinations.

Nanotechnology-driven therapies for neurodegenerative diseases: a comprehensive review

Neurological diseases, characterized by neuroinflammation and neurodegeneration, impose a significant global burden, contributing to substantial morbidity, disability and mortality. A common feature of these disorders, including stroke, traumatic brain injury and Alzheimer's disease, is the impairment of the blood-brain barrier (BBB), a critical structure for maintaining brain homeostasis. The compromised BBB in neurodegenerative conditions poses a significant challenge for effective treatment, as it allows harmful substances to accumulate in the brain. Nanomedicine offers a promising approach to overcoming this barrier, with nanoparticles (NPs) engineered to deliver therapeutic agents directly to affected brain regions. This review explores the classification and design of NPs, divided into organic and inorganic categories and further categorized based on their chemical and physical properties. These characteristics influence the ability of NPs to carry and release therapeutic agents, target specific tissues and ensure appropriate clearance from the body. The review emphasizes the potential of NPs to enhance the diagnosis and treatment of neurodegenerative diseases through targeted delivery, improved drug bioavailability and real-time therapeutic efficacy monitoring. By addressing the challenges of the compromised BBB and targeting inflammatory biomarkers, NPs represent a cutting-edge strategy in managing neurological disorders, promising better patient outcomes.

The Influence of Oxidative Stress Markers in Patients with Ischemic Stroke

Stroke is the second leading cause of death worldwide, and its incidence is rising rapidly. Acute ischemic stroke is a subtype of stroke that accounts for the majority of stroke cases and has a high mortality rate. An effective treatment for stroke is to minimize damage to the brain's neural tissue by restoring blood flow to decreased perfusion areas of the brain. Many reports have concluded that both oxidative stress and excitotoxicity are the main pathological processes associated with ischemic stroke. Current measures to protect the brain against serious damage caused by stroke are insufficient. For this reason, it is important to investigate oxidative and antioxidant strategies to reduce oxidative damage. This review focuses on studies assessing the concentration of oxidative stress biomarkers and the level of antioxidants (enzymatic and non-enzymatic) and their impact on the clinical prognosis of patients after stroke. Mechanisms related to the production of ROS/RNS and the role of oxidative stress in the pathogenesis of ischemic stroke are presented, as well as new therapeutic strategies aimed at reducing the effects of ischemia and reperfusion.

Injectable dual thermoreversible hydrogel for sustained intramuscular drug delivery

Herein, we reported novel docetaxel-decorated solid lipid nanoparticle (DCT-SLN)-loaded dual thermoreversible system (DCT-DRTS) for intramuscular administration with reduced burst effect, sustained release and improved antitumor efficacy. The optimized DCT-DRTs was subjected to in-vitro and in-vivo analyses. Antitumor evaluation of the DCT-DRTS was executed and compared with DCT-hydrogel, and DCT-suspension trailed by the histopathological and immune-histochemical analyses. The DCT-SLN gave a mean particle size of 157 nm and entrapment efficiency of 93 %. It was a solid at room temperature, and changed to liquid at physiological temperature due to its melting point of about 32 °C. Unlikely, poloxamer mixture remained liquefied at 25-27 °C, however converted to gel at physiological temperature. This behavior demonstrated opposed reversible property of the DCT-SLN and poloxamer hydrogel in DCT-DRTS system, making it ideal for intramuscular administration and quick gelation inside the body. The DCT-DRTS sustained the drugs release and unlike DCT-hydrogel, the preliminary plasma concentration of DCT-DRTS was significantly reduced, overcoming the burst release. A meaningfully enhanced antitumor efficacy and improved survival rate was observed from DCT-DRTS in tumor cell xenograft athymic nude mice. Additionally, increased apoptotic and reduced proliferation markers were observed in DCT-DRTS treated tumor masses. It was concluded that DCT-DRTS may be a suitable choice for intramuscular administration of DCT with sustained release, improved bioavailability, reduced toxicity and enhanced antitumor effects.

Sodium alginate-based smart gastro-retentive drug delivery system of revaprazan loaded SLNs; Formulation and characterization

Revaprazan (REV), a novel reversible Proton Pump Inhibitor (PPI) used to treat peptic ulcers, faces challenges in therapeutic efficacy due to its poor dissolution properties and a short half-life. Solid lipid nanoparticles (SLNs) have emerged as a drug delivery system capable of enhancing dissolution and bioavailability of lipid soluble drugs. Here, we report on the development and optimization of a smart gastro-retentive raft system of REV-loaded SLNs (GRS/REV-SLNs) to enhance drug bioavailability and gastric retention. The optimized REV-SLNs had a particle size of 120 nm, a Polydispersity Index (PDI) of 0.313, a zeta potential of -20.7 mV, and efficient drug incorporation of 88 %. Transmission Electron Microscopy (TEM) affirmed the spherical morphology of these REV-SLNs, while Fourier Transform Infrared Spectroscopy (FTIR) revealed no chemical interactions among components. In-vitro assessment of the final GRS/REV-SLNs demonstrated sustained gelation and buoyancy for over 12 h, which would significantly enhance REV retention and its release within the stomach. Further assessments in rats confirmed successful gel transformation within the stomach, resulting in the improved bioavailability of REV. Thus, the development of GRS/REV-SLNs significantly improved the delivery and bioavailability of REV within the stomach, and offers a potentially improved method of treating peptic ulcers.

Nano biomaterials based strategies for enhanced brain targeting in the treatment of neurodegenerative diseases: an up-to-date perspective

Neurons and their connecting axons gradually degenerate in neurodegenerative diseases (NDs), leading to dysfunctionality of the neuronal cells and eventually their death. Drug delivery for the treatment of effected nervous system is notoriously complicated because of the presence of natural barriers, i.e., the blood-brain barrier and the blood cerebrospinal fluid barrier. Palliative care is currently the standard care for many diseases. Therefore, treatment programs that target the disease's origin rather than its symptoms are recommended. Nanotechnology-based drug delivery platforms offer an innovative way to circumvent these obstacles and deliver medications directly to the central nervous system, thereby enabling treatment of several common neurological problems, i.e., Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral sclerosis. Interestingly, the combination of nanomedicine and gene therapy enables targeting of selective mutant genes responsible for the progression of NDs, which may provide a much-needed boost in the struggle against these diseases. Herein, we discussed various central nervous system delivery obstacles, followed by a detailed insight into the recently developed techniques to restore neurological function via the differentiation of neural stem cells. Moreover, a comprehensive background on the role of nanomedicine in controlling neurogenesis via differentiation of neural stem cells is explained. Additionally, numerous phytoconstituents with their neuroprotective properties and molecular targets in the identification and management of NDs are also deliberated. Furthermore, a detailed insight of the ongoing clinical trials and currently marketed products for the treatment of NDs is provided in this manuscript.

Phyllanthi Tannin Loaded Solid Lipid Nanoparticles for Lung Cancer Therapy: Preparation, Characterization, Pharmacodynamics and Safety Evaluation

The objective of the present study was to develop PTF-loaded solid lipid nanoparticles (PTF-SLNs) and investigate their efficacy in treating lung cancer. The PTF-SLNs were prepared by the thin film hydration method and verified by FTIR and TEM. Their physicochemical properties were characterized by particle size, polydispersity index (PDI), zeta potential, entrapment efficiency (EE), drug loading (DL), etc. Then, the pharmacodynamic studies of PTF-SLNs were performed on Lewis lung cancer cells and tumor-bearing mice. Finally, the safety studies were assessed by organ index, serum biochemical indicators, and histopathological changes. The PTF-SLNs were characterized by around 50 nm sphere nanoparticles, sustained ideal stability, and controlled drug release effects. The pharmacodynamic evaluation results showed that PTF-SLNs had stronger anti-tumor efficacy than PTF. An in vitro study revealed a more obvious cytotoxicity and apoptosis effect. The IC 50 values of PTF and PTF-SLNs were 67.43 μg/mL and 20.74 μg/mL, respectively. An in vivo study showed that the tumor inhibition rates of 2 g/kg PTF and 0.4 g/kg PTF-SLNs were 59.97% and 64.55%, respectively. The safety preliminary study indicated that PTF-SLNs improve the damage of PTF to normal organs to a certain extent. This study provides a nanoparticle delivery system with phenolic herbal extract to improve anti-tumor efficacy in lung cancer.