Role of Apoptosis in the Pathogenesis of Osteoarthritis: An Explicative Review.

Apoptosis is a complex regulatory, active cell death process that plays a role in cell development, homeostasis, and ageing. Cancer, developmental defects, and degenerative diseases are all pathogenic disorders caused by apoptosis dysregulation. Osteoarthritis (OA) is by far the most frequently diagnosed joint disease in the aged, and it is characterized by the ongoing breakdown of articular cartilage, which causes severe disability. Multiple variables regulate the anabolic and catabolic pathways of the cartilage matrix, which either directly or indirectly contribute to cartilage degeneration in osteoarthritis. Articular cartilage is a highly specialized tissue made up of an extracellular matrix of cells that are tightly packed together. As a result, chondrocyte survival is crucial for the preservation of an optimal cartilage matrix, and chondrocyte characteristics and survival compromise may result in articular cartilage failure. Inflammatory cytokines can either promote or inhibit apoptosis, the process of programmed cell death. Pro-apoptotic cytokines like TNF-α can induce cell death, while anti-apoptotic cytokines like IL-4 and IL-10 protect against apoptosis. The balance between these cytokines plays a critical role in determining cell fate and has implications for tissue damage and disease progression. Similarly, they contribute to the progression of OA by disrupting the metabolic balance in joint tissues by promoting catabolic and anabolic pathways. Their impact on cell joints, as well as the impacts of cell signalling pathways on cytokines and inflammatory substances, determines their function in osteoarthritis development. Apoptosis is evident in osteoarthritic cartilage; however, determining the relative role of chondrocyte apoptosis in the aetiology of OA is difficult, and the rate of apoptotic chondrocytes in osteoarthritic cartilage is inconsistent. The current study summarises the role of apoptosis in the development of osteoarthritis, the mediators, and signalling pathways that trigger the cascade of events, and the other inflammatory features involved.

QbD-based rivastigmine tartrate-loaded solid lipid nanoparticles for enhanced intranasal delivery to the brain for Alzheimer's therapeutics.

Alzheimer's disease (AD) is a neurodegenerative disease that affects a wide range of populations and is the primary cause of death in various countries. The treatment of AD is still restricted to oral conventional medicines that act only superficially. Fabrication of intranasal solid lipid nanoparticulate system for the uptake of therapeutic agents will act as a convincing approach with limited off-site toxicity and increased pharmacological activity. The objective of this study was to formulate, optimize, and evaluate the efficiency of rivastigmine tartrate (RT)-loaded intranasal solid lipid nanoparticles (SLNs) employing the solvent-evaporation diffusion method. To optimize the formulation parameters, the central composite design (CCD) was used. Lipid concentration (X1) and surfactant concentration (X2) were considered to be independent variables, while particle size (Y1), percentage entrapment efficiency (Y2), and percentage drug release (Y3) were considered as responses. The solid lipid was glyceryl monostearate, while the surfactant was polysorbate 80. The optimized formulation has a particle size of 110.2 nm, % entrapment efficiency of 82.56%, and % drug release of 94.86%. The incompatibility of drug excipients was established by differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR). Nasal histopathology tests on sheep mucosa revealed that the developed SLNs were safe to utilize for intranasal delivery with no toxicity. Ex vivo permeation investigations revealed that the flux and diffusion coefficients for RT solid lipid nanoparticles and RT solution were 3.378 g/cm2 /h and 0.310-3 cm2 /h, respectively. Stability studies demonstrated that the developed SLNs were stable when stored under various storage conditions. The viability and vitality of adopting a lipid particle delivery system for improved bioavailability via the intranasal route were also established in the in vivo pharmacokinetic investigations. According to the histopathological and pharmacokinetic investigations, the developed formulations were safe, non-lethal, efficient, and robust. These results suggest the potentiality provided by rivastigmine tartrate-loaded solid lipid nanoparticles for nasal delivery.

Intranasal Lipid Particulate Drug Delivery Systems: An Update on Clinical Challenges and Biodistribution Studies of Cerebroactive Drugs in Alzheimer's disease.

BACKGROUND: Alzheimer's is the primary cause of death in the various countries that affect wide strata of the population. The treatment of it is restricted to a few conventional oral medications that act only superficially. It is evident that the delivery of a drug to the brain across the blood-brain barrier is challenging as the BBB is armed with several efflux transporters like the P-glycoprotein as well as nasal mucociliary clearance adds up leading to decreased concentration and reduced therapeutic efficacy. Considering these, the intranasal IN route of drug administration is emerging as an alternative route for the systemic delivery of a drug to the brain. The intranasal (IN) administration of lipid nanoparticles loaded with cerebroactive drugs showed promise in treating various neurodegenerative diseases, since the nasal route allows the direct nose to brain delivery by means of solid lipid nanoparticles (SLN's). The tailoring of intranasal lipid particulate drug delivery systems is a pleasing approach to facilitate uptake of therapeutic agents at the desired site of action, particularly when a free drug has poor pharmacokinetics/ biodistribution (PK/BD) or significant off-site toxicities. OBJECTIVES: 1) In this review, key challenges and physiological mechanisms regulating intranasal brain delivery in Alzheimer's disease, ex vivo studies, pharmacokinetics parameters including brain uptake and histopathological studies are thoroughly discussed. 2) A thorough understanding of the in vivo behaviour of the intranasal drug carriers will be the elusive goal. 3) The article emphasizes to drag the attention of the research community working in the intranasal field towards the challenges and hurdles of the practical applicability of intranasal delivery of cerebroactive drugs. METHOD: Various electronic databases, journals like nanotechnology and nanoscience, dove press are reviewed for the collection and compilation of data. RESULTS: From in vivo biodistribution studies, pharmacokinetics parameters, and gamma scintigraphy images of various drugs, it is speculated that intranasal lipid particulates drug delivery system shows better brain targeting efficiency for various CNS disorders in comparison to other routes. CONCLUSION: Various routes are explored for the delivery of drugs to increase bioavailability in the brain for CNS disorders but the intranasal route shows better results that pave the way for success in the future if properly explored.