Aging is a multifunctional physiological manifestation. The nasal cavity is considered a major site for easy and cost-effective drug and vaccine administration, due to high permeability, low enzymatic activity, and the presence of a high number of immunocompetent cells. This review article primarily focuses on aging genetics, physical parameters, and the use of nanoparticles as delivery systems of drugs and vaccines via the nasal cavity. Studies have identified various genes involved in centenarian and average-aged people. VEGF is a key mediator involved in angiogenesis. Different therapeutic approaches induce vascular function and angiogenesis. FOLR1 gene codes for folate receptor alpha protein that helps in regulating the transport of vitamin B folate, 5-methyltetrahydrofolate and folate analogs inside the cell. This gene also aids in slowing the aging process down by cellular regeneration and promotes healthy aging by reducing aging symptoms. It has been found through the literature that GATA 6, Yamanaka factors, and FOLR1 work in synchronization to induce healthy and delayed aging. The role and applications of genes including CBS, CISD, SIRT 1, and SIRT 6 play a significant role in aging.

Molecular hydrogen is renowned as an odorless and colorless gas. The recommendations developed by China suggest that the inhalation of hydrogen molecules is currently advised in COVID-19 pneumonia treatment. The therapeutic effects of molecular hydrogens have been confirmed after numerous clinical trials and animal-model-based experiments, which have expounded that the low molecular weight of hydrogen enables it to easily diffuse and permeate through the cell membranes to produce a variety of biological impacts. A wide range of both chronic and acute inflammatory diseases, which may include sepsis, pancreatitis, respiratory disorders, autoimmune diseases, ischemia-reperfusion damages, etc. may be treated and prevented by using it. H₂ can primarily be inoculated through inhalation, by drinking water (which already contains H₂), or by administrating the injection of saline H₂ in the body. It may play a pivotal role as an antioxidant, in regulating the immune system, in anti-inflammatory activities (mitochondrial energy metabolism), and cell death (apoptosis, pyroptosis, and autophagy) by reducing the formation of excessive reactive O₂ species and modifying the transcription factors in the nuclei of the cells. However, the fundamental process of molecular hydrogen is still not entirely understood. Molecular hydrogen H₂ has a promising future in therapeutics based on its safety and possible usefulness. The current review emphasizes the antioxidative, anti-apoptotic, and anti-inflammatory effects of hydrogen molecules along with the underlying principle and fundamental mechanism involved, with a prime focus on the coronavirus disease of 2019 (COVID-19). This review will also provide strategies and recommendations for the therapeutic and medicinal applications of the hydrogen molecule.

The fermentative production of lactic acid from lignocellulosic biomass as a renewable feedstock addresses the challenges which include high feedstock costs, and biomass recalcitrance. These pretreatment processes, such as organosolv fractionation and high-solids enzymatic saccharification, enhanced sugar recovery by achieving a 566.6 g/bagasse Kg yield. The application of genetic engineering to lactic acid bacteria (LAB) improved efficiencies even further, as shown by the engineered strains Bacillus coagulans which achieved lactic acid yields of 110 g/L under optimized fermentation conditions. The application of advanced technologies like the use of twin-screw extrusion systems and green or eco-friendly solvent systems aided in the process efficiency and carbohydrate recovery. The study demonstrated the latest innovations, such as the application of CRISPR/Cas9 for strain improvement to overcome tolerances against inhibitors and optimize substrate utilization. Moreover, co-fermentation and integrated saccharification approaches upgraded the overall process of sustainable treatment and reduced the production cost. This review highlights the lactic acid (LA) potential in the sugar industry alongside its use in bio-based fuel production. Future research should concentrate on optimizing other genetically engineered techniques to improve LAB performance, exploring cost-effective and energy-efficient pretreatment and saccharification methods, incorporating lactic acid production into industrial processes, and addressing regulatory and market acceptance issues for genetically modified LAB in commercial applications. Graphical abstract