This is a working overview of Intranasal route, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-05-04. Anything still debated is marked as such rather than presented as settled.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
== Applications == Development of solid lipid nanoparticles is one of the fields of lipid nanotechnology (for a review on lipid nanotechnology, see ) with several potential applications in drug delivery, clinical medicine and research, as well as in other disciplines. Due to their size-dependent properties, lipid nanoparticles can possibly develop new therapeutics. The ability to incorporate drugs into nanocarriers offers a new prototype in drug delivery that could hold great promise for attaining bioavailability enhancement along with controlled and site-specific drug delivery. SLNs are also considered to be well tolerated in general, due to their composition from physiologically similar lipids. The conventional approaches such as use of permeation enhancers, surface modification, prodrug synthesis, complex formation and colloidal lipid carrier-based strategies have been developed for the delivery of drugs to intestinal lymphatics. In addition, polymeric nanoparticles, self-emulsifying delivery systems, liposomes, microemulsions, micellar solutions and recently, solid lipid nanoparticles (SLN) have been exploited as probable possibilities as carriers for oral intestinal lymphatic delivery.
In organic chemistry, an active ester is an ester functional group that is highly susceptible toward nucleophilic attack. Activation can be imparted by modifications of the acyl or the alkoxy components of a normal ester, say ethyl acetate. Typical modifications call for electronegative substituents. Active esters are employed in both synthetic and biological chemistry.
This discovery highlights how stromal cells are not just passive frameworks but are active regulators of lymphocyte survival and spatial arrangement. To conclude, the communication between adaptive immune cells shows that B and T zones rely heavily on the reticular network, which carry the small molecules and antigens described above. This reticular cell network helps maintain the proper distribution of immune cells and prevents overuse of one specific type of B or T cell by the immune system. By influencing antigen transport and various cell to cell signaling, reticular cells ensure that the immune response remains both balanced and efficient on a cellular level. Their structural make up and communication support adaptive immune system coordination.
He is currently a professor of ophthalmology at the University of Geneva, an adjunct clinical professor of ophthalmology at the Keck School of Medicine, University of Southern California, a research group leader of the Ocular Cell Biology Group at the Center for Applied Biotechnology and Molecular Medicine at the University of Zurich, a visiting professor at the University of Wenzhou, China, a research professor of ophthalmology at the NYU Grossman School of Medicine, and medical director of the ELZA Institute.
Sources: en.wikipedia.org
=== Structure === The proton pump, H+/K+ ATPase is a α,β-heterodimeric enzyme. The catalytic α subunit has ten transmembrane segments with a cluster of intramembranal carboxylic amino acids located in the middle of the transmembrane segments TM4, TM5, TM6 and TM8. The β subunit has one transmembrane segment with N terminus in cytoplasmic region. The extracellular domain of the β subunit contains six or seven N-linked glycosylation sites which is important for the enzyme assembly, maturation and sorting.
== Structure == The catalytic peptide of ALS in Arabidopsis thaliana (mouse-eared cress) is a chloroplastic protein consisting of 670 residues, the last 615 of which form the active form. Three main domains are found, with two thiamine pyrophosphate sandwiching a DHS-like NAD/FAD-binding domain. In SCOP assignment, these subunits are named d1yhya1, d1yhya2, and d1yhya3 from the N-terminal to the C-terminal. The structure of acetolactate synthase that was used for the picture on this page was determined using X-ray diffraction at 2.70 angstroms. There are five specific ligands that interact with this protein. The five are listed below.
is the density of the fluid at all points in the fluid. Bernoulli's equation and the Bernoulli constant are applicable throughout any region of flow where the energy per unit mass is uniform. Because the energy per unit mass of liquid in a well-mixed reservoir is uniform throughout, Bernoulli's equation can be used to analyze the fluid flow everywhere in that reservoir (including pipes or flow fields that the reservoir feeds) except where viscous forces dominate and erode the energy per unit mass. The following assumptions must be met for this Bernoulli equation to apply:
Sources: en.wikipedia.org
=== Post-hoc analysis and proton inventory === It is necessary to conduct a post-hoc analysis to determine the buffer or solvent-independent enthalpy from the experimental thermodynamics. The collected experimental data reflects not only the binding thermodynamics of the interaction of interest, but any contributing competing equilibria associated to it. A post-hoc analysis can be performed to determine the buffer or solvent-independent enthalpy from the experimental thermodynamics, by simply going through the process of Hess' law. Below example shows a simple interaction between a metal ion (M) and a ligand (L). B represents the buffer used for this interaction and
Inspired by their colleagues in Buffalo, workers at a Starbucks store in Mesa, Arizona, petitioned the NLRB for a union election on November 18, 2021, to be represented by Workers United. The organizing at the Mesa location stemmed from, in part, a well-liked manager being terminated after whistle-blowing on Starbucks' anti-union plan. Starbucks temporarily closed two stores participating in the union drive in October for renovations. The company claimed these closures were unrelated to the unionization efforts. Starbucks began working with Littler Mendelson, a self-described "union-busting firm", in October. Starbucks requested that the National Labor Relations Board include all Buffalo Starbucks locations in the union vote, however, the NLRB rejected this argument and declared store by store elections. Finally, on December 9, 2021, the workers at the Elmwood Avenue store became the first unionized Starbucks workers at a Starbucks owned location in the United States with a 19–8 vote. The Camp Road location voted 12–8 not to be in the union. Starbucks does have unionized locations in other countries. On December 13, workers at two Boston area locations petitioned the NLRB for union elections to be unionize with Workers United. The workers cited the win in Buffalo as inspiration for organizing. Workers in at least one location had most cards signed within a day. In February 2022, Starbucks fired seven workers in Memphis who had led the unionization effort and temporarily closed the store.
== Types == The mutated cells are mature T-lymphocytes and contain CD4+ receptors on the membrane surface. There are two variants of this mutated cell, Lutzner cells and Sézary cells. Sometimes these names are interchangeable, but it has been determined through histology that they are morphologically different.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.