lyophilization is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-12-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
| Property | Value | Notes |
|---|---|---|
| Common route | Intranasal | Also injected in some animal work |
| Solubility class | Freely soluble in water | Solid form is hygroscopic |
| Typical storage | About -20 degrees Celsius | Keep desiccated and dark |
| Purity method | Reverse-phase HPLC | Reported as area percent |
| Confirmatory method | Mass spectrometry | Verifies expected molecular mass |
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
=== 15 April === Four people were killed by Russian shelling in Siversk, Donetsk Oblast. Two people were killed in a separate attack in Lukiantsi, Kharkiv Oblast. Ukrainian media reported that the Ukrainian military launched a missile attack on a Russian command post in Crimea. The partisan group Atesh claimed that the headquarters of the 810th Marine Brigade in Sevastopol was struck. Ukrainian border guards intercepted a Russian sabotage group trying to enter Sumy Oblast.
=== GeneCore Facility === Provides transcriptomic services for academic and commercial users, including bulk, single-cell, and spatial transcriptomic analysis. Services include experimental design consultation, sample preparation, library preparation, sequencing, and data analysis.
{\displaystyle {\begin{aligned}&{\frac {dS}{dt}}=-{\frac {\beta IS}{N}},\\[6pt]&{\frac {dI}{dt}}={\frac {\beta IS}{N}}-\gamma I-\mu I,\\[6pt]&{\frac {dR}{dt}}=\gamma I,\\[6pt]&{\frac {dD}{dt}}=\mu I,\end{aligned}}}
== Editorship of journals == Editor-in-Chief, Journal of Current Biomedical Research (2017 to date) Associate Editor of African Journal of Pharmaceutical Sciences and Pharmacy Associate Editor, Journal of Pharmaceutical and Allied Sciences Member Editorial Board of American Journal of Pharmacotherapy and Pharmaceutical Sciences (2024)
=== Founding === Five Guys was founded in 1986 by Janie and Jerry Murrell. Jerry and the couple's sons Jim, Matt, Chad, and Ben were the original "Five Guys". The Murrells had a fifth son, Tyler, two years later. Today, all five sons, the current "Five Guys", are involved in the business: Matt and Jim travel the United States visiting stores, Chad oversees training, Ben selects the franchisees, and Tyler runs the bakery. The first Five Guys was in Arlington's Westmont Shopping Center. Buns were baked in the same center by Brenner's Bakery. This location closed, in favor of another in Alexandria, Virginia, at the intersection of King and North Beauregard Streets, which closed on September 21, 2013.
Sources: en.wikipedia.org
=== Combination chemotherapy and immunotherapy === To develop methods for the treatment of immunosuppressive cancers we combine polymer-drug conjugates with polymer – checkpoint inhibitor conjugates. Newly designed backbone degradable HPMA copolymer – anticancer drug conjugates possess long-circulating pharmacokinetics and enhanced antitumor activities, while keeping excellent biocompatibility. The conjugates induce immunogenic cell death in murine cancer models and convert “cold” tumors to “hot” ones that are susceptible to PD-L1 degradation immunotherapy. Original design of a new multivalent PD-L1 antagonist not only acts as a traditional checkpoint inhibitor, but mediates the surface crosslinking of PD-L1, biases its subcellular fate to lysosomes for degradation, and exhibits persistent suppression. Pre-clinical evaluation of the leading HPMA copolymer-epirubicin conjugate (KT-1) is being executed at the Nanotechnology Characterization Laboratory at NCI.
Initial letters are used where there is no ambiguity: C cysteine, H histidine, I isoleucine, M methionine, S serine, V valine. No other amino acids in this set begin with each of those letters. Where arbitrary assignment is needed, the structurally simpler amino acids are given precedence: A alanine, G glycine, L leucine, P proline, T threonine. For example, alanine is simpler than arginine or asparagine, the other amino acids starting with "a". F PHenylalanine and R aRginine are assigned by being phonetically suggestive, W tryptophan is assigned based on the double ring being visually suggestive to the bulky letter W, K lysine and Y tyrosine are assigned as alphabetically nearest to their initials L and T (note that U was avoided for its similarity with V, while X was reserved for undetermined or atypical amino acids); for tyrosine the mnemonic tYrosine was also proposed, D aspartate was assigned arbitrarily, with the proposed mnemonic asparDic acid; E glutamate was assigned in alphabetical sequence being larger by merely one methylene –CH2– group, N asparagine was assigned arbitrarily, with the proposed mnemonic asparagiNe; Q glutamine was assigned in alphabetical sequence of those still available (note again that O was avoided due to similarity with D), with the proposed mnemonic Qlutamine.
Most drugs are taken orally and are absorbed through the gastrointestinal tract. Antacids would increase the pH environment in the stomach and cause premature release of enteric coated drugs, which are designed to be protected from an acidic environment in stomach. For example, proton-pump inhibitors (PPIs) are enteric coated to protect them from decomposition under an acidic environment. Co-administration of antacids with PPIs would lead to premature release into acidic gastric environments and inactivate PPIs before absorption. These types of pharmacokinetics antagonism should be carefully avoided to prevent loss of drug efficacy. Since most drugs are either weakly acidic or weakly basic, modified pH would also affect the location at which the drug is deionised, thus affecting the required time for absorption and onset.
RVT-802 is an investigational treatment for congenital athymia, primarily associated with DiGeorge syndrome. It is a tissue-based therapy that consists of cultured donor thymus-derived tissue. RVT-802 consists of donor thymus-derived tissue that is cultured and surgically implanted into the recipient In patients with congenital athymia, the thymus gland is absent. Because of the crucial role the thymus gland plays in the maturation and differentiation of T cells, athymia results in severe immunodeficiency, typically resulting in death within the first two years of life. RVT-802 is manufactured by extracting thymus tissue from infants undergoing cardiac surgery, depleting it of immature T cells to prevent graft-versus-host disease, then implanting the processed tissue into the recipient's leg, where it fulfils the immunological role of the thymus.
Sources: en.wikipedia.org
There have been a significant number of publications since then, and a Food and Drug Administration panel voted, with some controversy, 20:3 that available studies "supported a signal of harm", but voted 22:1 to keep the drug on the market. The meta-analysis was not supported by an interim analysis of the trial designed to evaluate the issue, and several other reports have failed to conclude the controversy. This weak evidence for adverse effects has reduced the use of rosiglitazone, despite its important and sustained effects on glycemic control. Safety studies are continuing. In contrast, at least one large prospective study, PROactive 05, has shown that pioglitazone may decrease the overall incidence of cardiac events in people with type 2 diabetes who have already had a heart attack.
=== Detection in body fluids === Reviews that cover attention deficit hyperactivity disorder (ADHD) and phenethylamine indicate that several studies have found abnormally low urinary phenethylamine concentrations in ADHD individuals when compared with controls. In treatment-responsive individuals, amphetamine and methylphenidate greatly increase urinary phenethylamine concentration. An ADHD biomarker review also indicated that urinary phenethylamine levels could be a diagnostic biomarker for ADHD. Thirty minutes of moderate- to high-intensity physical exercise has been shown to induce an increase in urinary phenylacetic acid, the primary metabolite of phenethylamine. Two reviews noted a study where the mean 24 hour urinary phenylacetic acid concentration following just 30 minutes of intense exercise rose 77% above its base level; the reviews suggest that phenethylamine synthesis sharply increases during physical exercise during which it is rapidly metabolized due to its short half-life of roughly 30 seconds. In a resting state, phenethylamine is synthesized in catecholamine neurons from L-phenylalanine by aromatic amino acid decarboxylase at approximately the same rate as dopamine is produced. Monoamine oxidase deaminates primary and secondary amines that are free in the neuronal cytoplasm but not those bound in storage vesicles of the sympathetic neurone. Similarly, β-PEA would not be completely deaminated in the gut as it is a selective substrate for MAO-B, which is not primarily found in the gut.
2,000 military advisors from the PRC and the Soviet Union trained the Việt Minh guerrilla force with the aim of turning it into a full-fledged armed force to fight off their French colonial masters and gain national independence. On top of this, the PRC sent two People's Liberation Army (PLA) artillery battalions to fight at the siege of Dien Bien Phu on May 6, 1954, with one battalion operating the Soviet Katyusha multiple-rocket launcher systems (MRLS) against French forces besieged at Dien Bien Phu's valley. From 1950 to 1954 the Chinese government shipped goods, materials, and medicine worth $54 billion (in 2025 dollars) to Vietnam. From 1950 to 1956 the Chinese government shipped 155,000 small arms, 58 million rounds of ammunition, 4,630 artillery pieces, 1,080,000 artillery shells, 840,000 hand grenades, 1,400,000 uniforms, 1,200 vehicles, 14,000 tons of food, and 26,000 tons of fuel to Vietnam. Mao Zedong considered it necessary to buttress the Viet Minh to secure his country's southern flank against potential interference by westerners, while the bulk of the PRC's regular military forces participated in the Korean War from 1950 to 1953. After the end of the Korean War and the resolution of the First Taiwan Strait Crisis, China stepped up involvement in the Indochina Wars, viewing the presence of potentially hostile forces in Indochina as the main threat.
An advantage of the bacterial one-hybrid system over the yeast one-hybrid system (Y1H) lies in the higher transformation efficiency of plasmids into bacteria which allows for more complex “prey” libraries to be examined.
==== France ==== On 5 June 1916, Tolkien boarded a troop transport for an overnight voyage to Calais. Like other soldiers arriving for the first time, he was sent to the British Expeditionary Force's base depot at Étaples. On 7 June, he was informed that he had been assigned as a signals officer to the 11th (Service) Battalion, Lancashire Fusiliers. The battalion was part of the 74th Brigade, 25th Division. While waiting to be summoned to his unit, Tolkien sank into boredom. To pass the time, he composed a poem titled The Lonely Isle, which was inspired by his feelings during the sea crossing to Calais. To evade the British Army's postal censorship, he developed a code of dots by which Edith could track his movements. He left Étaples on 27 June 1916 and joined his battalion at Rubempré, near Amiens. He found himself commanding enlisted men who were drawn mainly from the mining, milling, and weaving towns of Lancashire. According to John Garth, he "felt an affinity for these working class men", but military protocol prohibited friendships with "other ranks". Instead, he was required to "take charge of them, discipline them, train them, and probably censor their letters ... If possible, he was supposed to inspire their love and loyalty." Tolkien later lamented, "The most improper job of any man ... is bossing other men. Not one in a million is fit for it, and least of all those who seek the opportunity."
Sources: en.wikipedia.org
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.
Reported human trials are few, brief and originate mainly from one country. They describe effects on anxiety-related measures, but sample sizes are small and reporting is limited. The results are widely regarded as preliminary rather than confirmed.
Reverse-phase liquid chromatography is used to assess purity and separation of related impurities. Mass spectrometry confirms that the observed molecular mass matches the expected peptide. A certificate of analysis from the supplier is the usual document of record.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.