intranasal delivery raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-03-12. Anything still debated is marked as such rather than presented as settled.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
=== Seed === Plant cryopreservation is becoming vital for its biodiversity value. Seeds are often considered as an important delivery system of genetic information. Cryopreservation of recalcitrant seed is the hardest due to intolerance to low temperature and low water content. However, plant vitrification solution can solve the problem and help recalcitrant seed (Nymphaea caerulea) cryopreserve.
While European ETSI standards have supported WMAS for several years, the U.S. Federal Communications Commission (FCC) officially adopted rules in February 2024 to allow WMAS operation in the United States. This regulatory change led to the introduction of wideband digital platforms such as Sennheiser’s Spectera and Shure’s Axient Digital PSM (ADPSM), which allow for bidirectional audio and increased spectral efficiency at large-scale events.
=== For evaluative well-being (life satisfaction) === Mental health is the strongest individual predictor of life satisfaction. Mental illness is associated with poorer well-being. In fact, mental health is the strongest determinant of quality of life at a later age. Studies have documented the relationship between anxiety and quality of life. The VOXEU analysis of happiness showed the principal determinants of an adult's life satisfaction to be income, parenting, family break up, mother's mental health and schooling. The factors that explain life satisfaction roughly map (negatively) to those factors that explain misery. They are first and foremost diagnosed depression/anxiety, which explains twice as much as the next factor, physical health (number of medical conditions), that explains just as much variance in subjective well-being between people, as income and whether someone is partnered. These factors count twice as much as each of whether someone is employed and whether they are a non-criminal, which in turn are 3 times as important as years of education. Overall, the best predictor of an adult's life satisfaction is their emotional health as a child as reported by the mother and child. It trumps factors like the qualifications that someone gets and their behaviour at 16 as reported by the mother. A child and therefore an adult's emotional health is most affected itself by a mother's mental health, which is just over twice as important as family income.
Sources: en.wikipedia.org
==== Endocrine actions ==== Valproic acid has been found to be an antagonist of the androgen and progesterone receptors, and hence as a nonsteroidal antiandrogen and antiprogestogen, at concentrations much lower than therapeutic serum levels. In addition, the drug has been identified as a potent aromatase inhibitor, and suppresses estrogen concentrations. These actions are likely to be involved in the reproductive endocrine disturbances seen with valproic acid treatment. Valproic acid has been found to directly stimulate androgen biosynthesis in the gonads via inhibition of histone deacetylases and has been associated with hyperandrogenism in women and increased 4-androstenedione levels in men. High rates of polycystic ovary syndrome and menstrual disorders have also been observed in women treated with valproic acid.
While roughly 400 public buildings in Ontario contain RAAC, the Science Centre is currently the only one in the province closed due to these concerns. The Ford government expedited its plan to relocate the Science Centre to the waterfront, targeting a 2028 opening, with a temporary location slated for January 2026. This drew further criticism, including from Moriyama Teshima Architects, the firm founded by the Science Centre's original architect. The architects offered to do pro bono design consulting services for the Government of Ontario to support immediate repairs to the roof, and called for other organizations to join the effort to facilitate repairs. Private donors, including Geoffrey Hinton, offered up to $1 million to fund repairs for the existing facility, but the province did not respond to these offers. By October 31, 2024, most of the exhibits had been moved to storage facilities in northern Toronto and Guelph, while the animals and plants had been transferred to the Toronto Zoo and The Village at Black Creek. Temporary pop-up exhibits have since opened at Sherway Gardens and Toronto's Harbourfront Centre.
While the galectin family as a whole has been widely recognized to be on the cell surface, the study of galectin's role in healing skin wounds is still being developed for therapeutic courses of action. Galectin-7 specifically promotes the re-epithelialization of the skin, kidney, corneal, and uterine wounds. While this protein is known for its role in epithelial homeostasis and apoptosis, it also functions as a modulator of adaptive immune responses within stratified epithelial tissues like the skin, cornea, and mucous areas. It has immunological effects that are derived from extracullar and intracellular roles like glycan binding. The response to damage and stress can modulate the secretion of epithelial-derived cytokines and promotion of immune activation or decreasing it. The enhancement of early inflammatory responses, regulation of cytokine secretion, modulation of immune-cell adhesion, apoptosis control, and altered immune landscapes in tumors are all local modulations of functions in epithelial stress responses to modulate immunity.
Sources: en.wikipedia.org
A challenge facing the field is that protein biomarkers for early diagnosis may be present in very low abundance. The lower limit of detection with conventional immunoassay technology is the upper femtomolar range (10−13 M). Digital immunoassay technology has improved detection sensitivity three logs, to the attomolar range (10−16 M). This capability has the potential to open new advances in diagnostics and therapeutics, but such technologies have been relegated to manual procedures that are not well suited for efficient routine use.
== Activity and Specificity == In common with most enzymes in family C1, caricain accepts hydrophobic amino acid residues in both S2 and S3. However, other residues are also accommodated in these subsites, including proline in S2, and lysine in S3. The specificities of three cysteine endopeptidases from papaya latex were found to be very similar. Caricain and chymopapain appeared to prefer an aliphatic to a hydrophobic residue at P2. The similarity in specificity of caricain and chymopapain was demonstrated by the fact that, of 44 peptide bonds in manatee hemoglobin cleaved by caricain, 29 were also cleaved by chymopapain. An earlier study had highlighted the similarity in specificity of caricain, chymopapain and papain. All seven bonds of the oxidized B chain of insulin that were hydrolyzed by caricain were also cleaved by papain, and six were hydrolyzed by chymopapain. Caricain can be assayed with Bz-ArgkNHPhNO2, kcat/Km being 187 M21 s21 at pH 6.8 and 40˚C. More sensitive substrates may employ a fluorometric leaving group, kcat/Km for the hydrolysis of Z-Phe-ArgkNHMec being 1.06 3 106 M21 s21 (pH 6.8, 40˚C). The enzyme exhibits a broad pH-activity profile, with the optimum near 7.0. About half-maximal activity is still achieved at pH values of about 5.3 and 8.3, and the profile is reported to be governed by at least three ionizing groups. The active-site sulfur requires reduction for catalytic competence, and this is best achieved by the inclusion of low millimolar concentrations of cysteine in assay buffers.
The visualization of single molecules, single cells, biological tissues, and nanomaterials is an important and attractive approach in analytical science. Also, hybridization with other traditional analytical tools is revolutionizing analytical science. Microscopy can be categorized into three different fields: optical microscopy, electron microscopy, and scanning probe microscopy. Recently, this field is rapidly progressing because of the rapid development of the computer and camera industries.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。