Intranasal administration of sertraline ensures sustained brain delivery and antidepressant effect in a mouse model of depression

Simultaneous induction of systemic hyperglycaemia and stress impairs brain redox homeostasis in the adult zebrafish

For diabetic patients it is crucial to constantly monitor blood glucose levels to mitigate complications due to hyperglycaemia, including neurological issues and cognitive impairments. This activity leads to psychological stress, called "diabetes distress," a problem for most patients living with diabetes. Diabetes distress can exacerbate the hyperglycaemia effects on brain and negatively impact the quality of life, but the underlying mechanisms remain poorly explored. We simulated diabetes distress in adult zebrafish by modelling hyperglycaemia, through exposure to dextrose solution, along with chronic unpredictable mild stress (CUMS), and evaluated brain redox homeostasis by assessing reactive oxygen species (ROS) content, the antioxidant system, and effects on mitochondrial biogenesis and fission/fusion processes. We also evaluated the total, cytosolic and nuclear content of nuclear factor erythroid 2-related factor 2 (NRF2), a critical regulator of redox balance, in the whole brain and total NRF2 in specific brain emotional areas. The combined CUMS + Dextrose challenge, but not the individual treatments, reduced total NRF2 levels in the entire brain, but strongly increased its levels in the nuclear fraction. Compensatory upregulation of antioxidant genes appeared inadequate to combat elevated levels of ROS, leading to lowering of the reduced glutathione content and total antioxidant capacity. CUMS + Dextrose treatment also upregulated transcription factors implicated in mitochondrial biogenesis and dynamics with a predominance of fission, which is consistent with increased oxidative stress. In conclusion, this study highlights the close interplay between hyperglycaemia and psychological distress causing overriding oxidative stress in the brain, rendering the organism vulnerable to the development of disease complications.

Advanced drug delivery technologies for postmenopausal effects

Postmenopause is the 12-month absence of menstrual periods, characterized by decreased estrogen and progesterone levels, leading to physical and psychological alterations such as hot flashes, mood swings, sleep disruptions, and skin changes. Present postmenopausal treatments include hormone replacement therapy, non-hormonal drugs, lifestyle modifications, vaginal estrogen therapy, bone health treatments, and alternative therapies. Advanced drug delivery systems (ADDSs) are essential in managing postmenopausal effects (PMEs), offering targeted and controlled delivery to alleviate symptoms and improve overall health. This review emphasizes such ADDSs for addressing PMEs. Emerging trends such as artificial ovaries are also reviewed. Additionally, the prospects of technologies such as additive manufacturing (3D and 4D printing) and artificial intelligence in further tailoring therapeutic strategies against PMEs are provided.

Research progress in brain-targeted nasal drug delivery

The unique anatomical and physiological connections between the nasal cavity and brain provide a pathway for bypassing the blood-brain barrier to allow for direct brain-targeted drug delivery through nasal administration. There are several advantages of nasal administration compared with other routes; for example, the first-pass effect that leads to the metabolism of orally administered drugs can be bypassed, and the poor compliance associated with injections can be minimized. Nasal administration can also help maximize brain-targeted drug delivery, allowing for high pharmacological activity at lower drug dosages, thereby minimizing the likelihood of adverse effects and providing a highly promising drug delivery pathway for the treatment of central nervous system diseases. The aim of this review article was to briefly describe the physiological structures of the nasal cavity and brain, the pathways through which drugs can enter the brain through the nose, the factors affecting brain-targeted nasal drug delivery, methods to improve brain-targeted nasal drug delivery systems through the application of related biomaterials, common experimental methods used in intranasal drug delivery research, and the current limitations of such approaches, providing a solid foundation for further in-depth research on intranasal brain-targeted drug delivery systems (see Graphical Abstract).