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Prevention and Treatment of Alzheimer’s Disease in the Light of Ayurveda
Published in Atanu Bhattacharjee, Akula Ramakrishna, Magisetty Obulesu, Phytomedicine and Alzheimer’s Disease, 2020
Vinayak Majhi, Bishnu Choudhury, Sudip Paul
In the absorption of drugs from the nasal cavity, the first step is passage through the mucus. Large and charged particles may find it more difficult to cross, but small and uncharged particles easily pass through this layer (Srikanth et al. 2011). Mechanisms for absorption of drugs through the nasal mucosa include the following: The paracellular route is the first transport mechanism, which is an aqueous route of transport. This is a slow and passive route.The transcellular process is the second mechanism of transport, through a lipoidal route, and is responsible for the transport of lipophilic drugs that show an absorption rate dependent on their lipophilicity. Drugs also cross cell membranes by an active transport route via carrier-mediated means or transport through the opening of tight junctions.
Immune function of epithelial cells
Published in Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald, Principles of Mucosal Immunology, 2020
Richard S. Blumberg, Wayne Lencer, Arthur Kaser, Jerrold R. Turner
Many luminal materials, including hydrophilic nutrients, are transported by distinct transport proteins within apical and basolateral domains. Most often, apical transporters take advantage of the steep, electrochemical Na+ gradient (from extracellular to intracellular) to provide the driving force for absorption. The basolateral Na+-K+ATPase that maintains the Na+ gradient and pumps apically transported Na+ ions across the basolateral membrane is, therefore, essential to ongoing nutrient transport. Paracellular recycling of Na+ ions from the lamina propria to the lumen (via the tight junction, as discussed later) is essential, as the diet does not otherwise contain sufficient Na+ to support ongoing apical absorption. Solutes absorbed by apical transmembrane transport proteins cross the basolateral membrane via facilitated transporters that operate in a strictly concentration-dependent manner. This allows the basolateral transport proteins to drive nutrient absorption from the enterocyte cytoplasm toward the bloodstream when nutrients are being actively absorbed but to also operate in the reverse direction in order to bring nutrients into the enterocyte when none are present in the lumen, e.g., during fasting. Whether by vesicles or transmembrane transport proteins, transport of solutes, membranes, and cargo from one side, through the cell to the other side, is termed the “transcellular pathway” and is an energy-dependent process.
Applications of Nanoparticles in the Treatment of Gliomas
Published in Hala Gali-Muhtasib, Racha Chouaib, Nanoparticle Drug Delivery Systems for Cancer Treatment, 2020
Gerardo Caruso, Elena Fazzari, Salvator M. Cardali, Maria Caffo
Intranasal delivery is an important way to bypass the BBB. In fact, the respiratory region of the nasal cavities is considered to be the site of best pharmacological absorption of systemic circulation. The types of transport exploited are the classical transcellular, paracellular, transcytosis, and carrier-mediated transport. This method has the advantages of rapid absorption, avoiding first-passage metabolism and the lack for the need of alterations in the BBB. Medications are released in the cerebrospinal fluid or in the brain through the olfactory mucosa, exploiting the connective tissue surrounding the olfactory nerve or the axons that form it. A recent study investigated the efficacy of the use of nanocapsules for the release of olanzapine through intranasal administration. The nanocapsules come into contact with the olfactory mucosa through continuous washes with solutions containing these NPs. However, intranasal delivery shows important limitations; the olfactory region of the nasal epithelium corresponds to about 5% in humans and, therefore, in many cerebral regions, the release of medication does not permit the achievement of therapeutic doses [33]. Intranasal mucosa is damaged by repeated use of this route of administration and, moreover, a discrete dose of medication is often eliminated by the mucociliary clearance system [33].
Anti-ageing peptides and proteins for topical applications: a review
Published in Pharmaceutical Development and Technology, 2022
Mengyang Liu, Shuo Chen, Zhiwen Zhang, Hongyu Li, Guiju Sun, Naibo Yin, Jingyuan Wen
The transcellular pathway refers to the transportation of solutes through a cell, including transcellular passive diffusion, transcellular active transport, and transcytosis (Kasting et al. 2019). Diffusion is the movement of chemicals from a region of higher concentration to a region of lower concentration. Active transport, also known as carrier-mediated transport, involves using energy to help specific molecules move across the barrier and against the concentration gradient (Fung et al. 2018). Since the cell membrane is lipophilic, it might resist the passive diffusion of hydrophilic or charged compounds. Transcytosis is another type of transcellular route, where macromolecules are carried across the cell membranes (Liu et al. 2019). These macromolecules are captured in vesicles on the side of the cell, drawn across the cell, and then ejected on the other side (Liu et al. 2019). However, most experimental studies suggest that the primary pathway across SC is the intercellular pathway, as described below.
Nanostructured lipid carriers engineered for intranasal delivery of teriflunomide in multiple sclerosis: optimization and in vivo studies
Published in Drug Development and Industrial Pharmacy, 2019
Dnyandev G. Gadhave, Chandrakant R. Kokare
At the same time, the steady-state flux (Jss) and permeability coefficient (Papp) of TFM-loaded nanoparticles were calculated and summarized in Table 4. The Jss of TFM-NLC and TFM-MNLC were found 54.490 ± 2.03 and 83.105 ± 1.25 µg/cm2/h, respectively. TFM-MNLC formulation produced rapid permeation of TFM across the nasal mucosa. Hence, the Jss and Papp of TFM-MNLC were highly significant than the TFM-NLC [24,35]. The i.n. drug delivery was occupied by two major pathways such as transcellular and paracellular transport. Lipid nanocarriers have an ability to enhance the rate of TFM permeation through the paracellular and transcellular pathway. Mucoadhesive agents were responsible for opening the tight junction of a barrier hence, TFM-MNLC formulation could be referred as a potential delivery tool.
Evaluating the safety profile of focused ultrasound and microbubble-mediated treatments to increase blood-brain barrier permeability
Published in Expert Opinion on Drug Delivery, 2019
Dallan McMahon, Charissa Poon, Kullervo Hynynen
Currently, strategies to circumvent the BBB for the delivery of therapeutics rely on altering paracellular transport (e.g. hyperosmotic solutions [8]), transcellular transport (e.g. carrier protein-mediated transport [9]), or on utilizing delivery routes outside of the circulatory system (e.g. intracranial injections [10], intranasal delivery [11], hydrogels [12]). Although hyperosmotic solutions may be helpful for neurological diseases that require treating large volumes of brain tissue, the use of such reagents can lead to structural alterations to neurons, lesions, macrophage accumulation, and glial activation [13]. Other strategies for bypassing the BBB suffer from their invasive nature, non-targeted delivery, or non-therapeutically relevant concentrations of drug delivery.