Available online on 15.06.2025 at http://jddtonline.info

Journal of Drug Delivery and Therapeutics

Open Access to Pharmaceutical and Medical Research

Copyright  © 2025 The  Author(s): This is an open-access article distributed under the terms of the CC BY-NC 4.0 which permits unrestricted use, distribution, and reproduction in any medium for non-commercial use provided the original author and source are credited

Open Access Full Text Article                                                    Review Article

Drugs based on bioactive oligopeptides

O.V. Ledenev ^1,2*, O.V. Levitskaya ², A.V. Syroeshkin ²

¹ Department of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia

² Department of Pharmaceutical and Toxicological Chemistry, Peoples Friendship University of Russia (RUDN University), 6 Miklukho - Maklaya St, Moscow, 117198, Russia

 

 

Introduction 

The production of peptide therapeutics is a classic example of green chemistry ¹. The biological origin and non-toxic degradability of these medicinal substances in combination with the recycling of blisters and paper packaging, as well as various types of "green" synthesis are modern vectors of the development of pharmacy². Preclinical trials of oligopeptide molecules have shown that, due to their bio-origin, they have a safe action profile in tests on animals in terms of acute-chronic toxicity ³. Peptide compositions daily demonstrate their effectiveness against cancers ⁴, show increased antibacterial activity in a number of studies ^5–7, improve the permeability of cell membranes ⁸, and improve the pharmacokinetic parameters of medicinal substances ⁹. Peptide compositions are widely used as a complex therapeutic in the treatment of many diseases ¹⁰, they significantly improve cognitive functions in the fight against Alzheimer's disease ¹¹ and improve physiological parameters in ophthalmological therapy ^12,13. The following sections will describe the methods of peptide therapeutics production, their dosage forms available on the pharmaceutical market, the composition of finished therapeutics, the targets of the action of oligopeptides, and the pharmacokinetic parameters that contribute to this.

Modern peptide molecules are obtained in two ways: artificial and natural ^14,15. The difference between these ways is that the natural method uses extracts from tissues, organs of animals and plants. ^16,17, and artificial synthetic methods involve the synthesis of amino acid sequences de novo ¹⁸.

The natural production method depends on the biological entity (animal tissue, plant material, cell culture, including recombinant cells ^19,20.

The process flow for obtaining a peptide from biomaterials resembles the classical scheme of chemical-toxicological preparative purification and includes the following operations: Obtaining an organ/tissue/cell containing the peptide → Homogenization with the addition of a preservative to extend the shelf life of the homogenates → Purification of the homogenate by any convenient method → Formation of extracts with different pH values. If the final objective is an extract, we shall stop at this step and proceed with purifying the extract by high-performance liquid chromatography. If the final objective is a specific oligo- or polypeptide, we shall move on to the next step → Purification of the extract → Centrifugation or a similar method for separating peptide molecules ²¹ → Purification of the peptide by any available chromatography ²² → Purity and authenticity analysis using a mass spectrometer ²³. Despite chromatographic purification, the resulting oligopeptide therapeutics still carry the threat of toxic impurities for plant extracts ²⁴, HPV impurities (for extracts from cell cultures) ²⁵, and prion impurities (for extracts from animal tissues, especially for brain extracts) ^26–28.

The artificial method is quite diverse; a number of studies demonstrate that research teams in many countries are trying to move away from the use of animal-based oligopeptides to synthetic ones. ²⁹. 

The most popular method for creating oligo- and polypeptide chains is solid-phase synthesis with the protecting group Fmoc PG (Fluorenylmethyloxycarbonyl protecting group) ³⁰.

The method consists in creating a solid-phase peptide resin (the most popular are: Merrifield resin ³¹, polyethylene glycol-grafted polystyrene (PEG-PS) ³², acrylamidopropyl polyethylene glycol (PEGA) ³³).

The solid-phase synthesis method is used for continuous creation of peptides³⁴, being a process amenable to automation³⁵ when the operator only needs to add Fmoc PG protected amino acids in the desired sequence. The principle of working with Merrifield resin ³⁶is as follows: Treatment of the resin with a Fmoc PG protected amino acid in an alkaline medium → removal of the Fmoc protection → addition of the second amino acid with Fmoc PG as an acylating agent to the first amino acid, which results in the formation of a peptide bond → removal of the protective group and addition of the amino acid with Fmoc PG again → and so on until the required peptide is assembled → cleavage of the resulting peptide from the resin at the end → purification by reversed-phase chromatography ³⁷. The following methods of artificial peptide synthesis are not the most common ones, but used: liquid-phase and recombinant. The most important difference between the liquid-phase and solid-phase peptide synthesis methods is that the growing sequence of amino acids is protected by reagents in the liquid phase ³⁸. 

In this section, we will consider a wide range of dosage forms (DF) of peptide therapeutics and their excipients (ES). The dosage forms of peptides available on the pharmaceutical market of the Russian Federation are quite diverse: Injectable form (subcutaneous ³⁹, intramuscular ⁴⁰, intravenous ⁴¹, parabulbar ⁴²); Therapeutics for oral administration (tablets ⁴³); Therapeutics for external use (nasal form ⁴⁴, ointments and creams ⁴⁵); Suppositories ⁴⁶.

The most popular representatives of the injectable form are the oligopeptide semaglutide ⁴⁷ and liraglutide ⁴⁸ – an analogue of glucagon-like peptide-1 (GLP-1), and the peptide hormone insulin ⁴⁹. The finished dosage form is a pre-filled pen: for convenient dosing of the therapeutic and independent administration of the therapeutic. However, this selection of peptide therapeutics is not not exhaustive; the pharmaceutical market often finds a therapeutic of polypeptides obtained from the cerebral cortex of cattle in prescriptions of a neurologist ⁵⁰, polypeptides from the retina of cattle in prescriptions of an ophthalmologist ⁵¹, polypeptides of the pineal gland of cattle in prescriptions of an obstetrician-gynecologist ⁵², VLP (virus like particles) vaccines in prescriptions of an epidemiologist and therapist ⁵³ – all these therapeutics are lyophilisates, which are subsequently dissolved in water for injection or a 0.9% sodium chloride solution to create a finished dosage form. The main excipients and their properties are described in Table 1.

 

 

Table 1: Brief description of excipients of injectable forms of peptide therapeutics.

Name	Characteristics and application	Dosage form
Glycine	The simplest amino acid can be used both as an active substance and as an excipient. The literature describes the positive effect of the [oligo/polypeptide + glycine] complex on the pharmacokinetic parameters of the finished dosage form 54	Lyophilisate          ↓ Solution for injection
Disodium hydrogen phosphate dihydrate	Inorganic sodium salt used as a pH regulator, as a buffering agent	Solution for injection in pre-filled pens
Propylene glycol	Organic molecule used as a stabilizer and solvent when the amino acid sequence consists mainly of hydrophobic amino acids	Solution for injection in pre-filled pens
Phenol	The so-called carbolic acid, which serves as a preservative, helps prevent the growth of bacteria and contamination of solutions	Solution for injection in pre-filled pens
Hydrochloric acid	Inorganic acid used to correct pH	Solution for injection in pre-filled pens
Sodium hydroxide	Inorganic base used to correct pH	Solution for injection (pre-filled pens, ampoules)
Water for injection	Water corresponding to the article of the same name of the General Pharmacopoeia Monograph, used as a solvent	Solution for injection (pre-filled pens, ampoules)
Zinc chloride	Inorganic zinc salt used as a stabilizer for the hexameric form of the insulin molecule, which prevents its degradation during storage 55	Solution for injection in pre-filled pens
Glycerol	Simple triol compound used as a stabilizer for protein molecules, as a component of a storage buffer, and as a solvent.	Solution for injection in pre-filled pens
Meta-Cresol (m-Cresol)	Organic aromatic compound used as a preservative in sterile dosage forms 56	Solution for injection in pre-filled pens
Tromethamol (tromethamine)	Organic amine used as a buffering agent and as an alkalinizer.	Solution for injection in pre-filled pens
Polysorbate 20	Derived from sorbitol, used as a solvent, stabilizer and emulsifier	Solution for injection in pre-filled pens

 

 

The tablet form of peptide therapeutics is not very common due to the fact that biomolecules undergo hydrolysis when taken orally ⁵⁷. However, many research teams have addressed this problem, using various techniques to protect against peptidases. Some manufacturers chemically modify the molecule ^58,59, others cyclize the peptide ⁶⁰. Different methods are presented in Section 3, Pharmacokinetics and Pharmacodynamics of Peptide Therapeutic Agents. 

An example of tablet forms on the Russian pharmaceutical market is the pentadecapeptide therapeutic used to treat infectious and inflammatory diseases of the mouth and throat – Gramicidin C ⁶¹. Another example of a tablet form is glucosaminylmuramyl dipeptide (GMDP) used to treat chronic respiratory tract infections, acute and chronic purulent-inflammatory diseases of skin and soft tissues ⁶². A brief description of excipients for the creation of peptide tablets that allow action under conditions of oral administration is given in Table 2.

 

 

 

Table 2: Excipients for making tablet dosage forms of peptides

Name	Characteristics and application
Colloidal dioxide	Anti-adhesive agent, reduces the sticking of mass to equipment in the course of tablet manufacture
Talc	Anti-adhesive agent and glidant, improves the flow properties of powders and granules
Acesulfame potassium	Sweetener, used to adjust taste
Mint flavoring	Organoleptic substance, imparts a pleasant taste and aroma
Sorbitol	Filler and moisturizer, adds volume, improves consistency
Magnesium stearate	Lubricant, reduces friction between particles 63, improves the tableting process
Lactose monohydrate	Filler, provides volume and mass of solid dosage forms
Sucrose	Filler and binder, provides strength to tablets
Potato starch	Filler and disintegrant, improves disintegration of tablets
Methylcellulose	Thickener and stabilizer, forms viscous solutions
Calcium stearate	Lubricant, reduces friction between particles

 

 

 

Peptides have found wide application in skin care products ⁶⁴ as agents stabilizing the condition of the skin ⁶⁵, in addition, most therapeutics with oligopeptides and polypeptides are available in the form of nasal drops/sprays ⁶⁶, for example, the heptamerous peptide complex (Met-Glu-His-Phe-Pro-Gly-Pro) is used to treat most pathological conditions caused by brain injuries and neurotic disorders of various origins ⁶⁷. The nasal form of another heptamerous peptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro (diacetate)) has an anti-anxiety effect with antidepressant and antiasthenic action ⁶⁸, and therapeutics with interferons of various origins help fight various infections ⁶⁹. 

Suppositories with peptides find their application in anti-infective therapy ⁷⁰ and as a treatment agent for chronic prostatitis ⁷¹. You can see the characteristics of the excipients of all listed dosage forms in Table 3.

 

 

Table 3: Excipients for making of nasal drops and suppositories based on peptides

Name	Characteristics and application	Dosage form
Methyl parahydroxybenzoate (nipagin)	Antimicrobial preservative, especially effective against bacteria and yeast 72	Drops
Purified water	Universal solvent, does not contain impurities, used as a base for drops	All dosage forms
Edetate disodium dihydrate	Complexing agent, stabilizer, antioxidant	Drops
Sodium hydrogen phosphate dodecahydrate	pH regulator, buffering agent	Drops
Potassium dihydrogen phosphate	pH regulator, buffering agent	Drops
Povidone	Stabilizer, binder, solvent	Suppositories
Macrogol 4000	Variant of suppository base	Suppositories
Cocoa butter	Suppository base	Suppositories
Lanolin anhydrous	Emulsifier, base for suppositories and ointments, improves penetration of active substances	Suppositories, ointments
Solid fat	Suppository base	Suppositories, ointments

 

 

Peptide therapeutic agents have a potential to be used in all areas of evidence-based medicine. The ability to synthesize different amino acid sequences allows for variation in the pharmacokinetics and pharmacodynamics of finished dosage forms ⁷³. This section will use scientific data to demonstrate the positive results that scientists have achieved to date and will also touch upon the future of peptide therapeutics.

In most instructions for peptide injection forms of therapeutics, you can find the phrase: "the therapeutic consists of a balanced and stable peptide mixture with polyfunctional activity, which does not allow the pharmacokinetic analysis of individual components". It corresponds to the logical conclusion about the specificity of administration, however other dosage forms allow measuring pharmacokinetic parameters, for example: the bioavailability of GMDP tablets is 7-13%. This bioavailability indicator allows research teams to propose solutions that are not suitable for most drugs, for example, a research team from China has synthesized a cyclic peptide using the method of through cyclization with disulfide bridges, as a result they managed to increase the stability and antibacterial activity of the molecule, as well as increase its half-life ⁷⁴. Italian scientists propose several methods for creating cross-linked peptides, which are basically arranged in an -helix, using cross-linking agents (obtained by connecting the side chains of suitable modified amino acids located at the required distance within the peptide chain) to improve a number of properties of the active substance ⁷⁵. Other researchers propose a physical option to fight against poor pharmacokinetics, such as using a self-orienting swallowable device consisting of a stainless steel core and low-density polycaprolactone that autonomously releases peptide-containing microneedles into the gastric epithelium ⁷⁶. 

A huge area that is gaining momentum every year is the use of peptides in various forms: 1) as an independent nanoparticle (NP); 2) as a complex of peptide + nanoparticle. This step allows improving the biological activity of the molecule – a pharmaceutical agent ⁷⁷, allows selectively choosing a target for the delivered therapeutic ⁷⁸ and peptide ⁷⁹; a variation in the preparation of a peptide-equipped nanoparticle, encapsulation of the peptide in liposomal nanoparticles ⁸⁰, or in polymeric NPs ⁸¹, allows increasing the bioavailability of the peptide agent several times. At the moment, there are studies where insulin is enclosed in liposomal nanoparticles to protect the polypeptide from oral degradation and ensure the ease of drug administration; many studies are aimed at using metal nanoparticles with peptides as antibacterial activity boosters ⁸² and as contrast agents ⁸³.

The qualitative and quantitative approach to the quality control of peptide therapeutics includes many instrumental methods of analysis: 

• Chromatographic methods: high-performance liquid chromatography with tandem mass spectrometry⁸⁴; reversed phase high performance liquid chromatography⁸⁵; ion-exchange chromatography⁸⁶; thin-layer chromatography⁸⁷; affinity (biospecific) chromatography⁸⁸; adsorption chromatography⁸⁹; group-specific chromatography⁹⁰; metal-chelate affinity chromatography ⁹¹; covalent thiol-sepharose chromatography⁹²; reversed phase chromatography⁹³, as well as gel filtration as a type of sieve chromatography⁹⁴.
• Electrophoretic methods: polyacrylamide gel electrophoresis (gel electrophoresis) ⁹⁵; moving-boundary electrophoresis (frontal electrophoresis) ⁹⁶; disk electrophoresis ⁹⁷; isotachophoresis ⁹⁸; isoelectric focusing ⁹⁹; two-dimensional gel electrophoresis ¹⁰⁰; pulsed-field gel electrophoresis ¹⁰¹.
• Centrifugation methods: analytical ultracentrifugation ¹⁰²; zonal high-speed and isopycnic centrifugation ¹⁰³.
• Spectral methods: mass spectrometry¹⁰⁴; dynamic laser light scattering ¹⁰⁵; small-angle laser light scattering ¹⁰⁶; dispersion analysis in turbid and opaque media – two-dimensional dynamic laser light scattering ¹⁰⁷; spectroscopy in the ultraviolet (UV)¹⁰⁸, visible and infrared (IR) bands ¹⁰⁹.

The diversity of approaches to biomolecule analysis plays a key role in the comprehensive study of its characteristics used in quality control. But all these methods have one big drawback – a destructive approach to the studied object. Thus, creation of a non-invasive quality control method is a priority for pharmacists. For example, researchers from RUDN University, Moscow, have managed to implement a new non-invasive method for detecting inherent radiothermal emission of biologically active nanoparticles ^110–114, which is easily applicable to peptide molecules. Analyzing the literature on peptide therapeutics, we can come to the conclusion that the mechanism of action of peptides is not always clear to analysts due to the fast biotransformation of peptide molecules; nevertheless, it is effective and clinical medicine proves it; of course, this does not apply to those peptide therapeutics that are structural analogues of various hormones and other biostructures, for which the mechanism of action has been thoroughly studied, but for most active peptide molecules it is still unknown. It allows a hypothesis that peptide bioregulators are included in a number of physicochemical characteristics of the cell (temperature, pressure, osmotic pressure, pH, dynamism, selective permeability) – electromagnetic fields of the cell. Considering the fact that this emission is possible only for nanoparticles, and most peptides are such, the pieces of the possible puzzle of regulation of the internal environment of the cell by peptides fall into place. Perhaps their property of radiothermal emission allows stabilizing the electromagnetic fields of all cells, because it is not uncommon for a peptide therapeutic to be effective where a classic therapeutic has already stopped working. Perhaps this hypothesis is the answer to the question about the mechanism of action of oligo- and polypeptides. In the future, further study of peptides is planned, both from the pharmaceutical point of view with approaches to quality control of peptide therapeutic agents, and from the biochemical point of view to clarify their mechanism of action.

Conflicts of Interest: The authors declare that they have no conflicts of interest.

Contributors: All authors have read and approved the final manuscript.

Acknowledgment: The authors would like to express their deepest gratitude to the staff of the Department of Pharmaceutical and Toxicological Chemistry RUDN University.

Source of Support: This paper was supported by the RUDN University Strategic Academic Leadership program.

Funding: This publication was supported by the RUDN University Scientific Projects Grant System, project No. 033323-2-000

Data Availability Statement: The data presented in this study are available on request from the corresponding author.

REFERENCES

1.     Leko M, Filippova P, Rustler K, Bruckdorfer T, Burov S. Solid‐Phase Synthesis of Peptide Hydrazides: Moving Toward Green Chemistry. Journal of Peptide Science 2025;31. https://doi.org/10.1002/psc.70010.

2.     Wang T, Zhang Y-R, Liu X-H, Ge S, Zhu Y-S. Strategy for the Biosynthesis of Short Oligopeptides: Green and Sustainable Chemistry. Biomolecules 2019;9:733. https://doi.org/10.3390/biom9110733.

3.     Yang H, Cao J, Lin X, Yue J, Zieneldien T, Kim J, et al. Developing an Effective Peptide-Based Vaccine for COVID-19: Preliminary Studies in Mice Models. Viruses 2022;14:449. https://doi.org/10.3390/v14030449.

4.     Zhang L, Huang Y, Lindstrom AR, Lin T-Y, Lam KS, Li Y. Peptide-based materials for cancer immunotherapy. Theranostics 2019;9:7807–25. https://doi.org/10.7150/thno.37194.

5.     Deo S, Turton KL, Kainth T, Kumar A, Wieden H-J. Strategies for improving antimicrobial peptide production. Biotechnol Adv 2022;59:107968. https://doi.org/10.1016/j.biotechadv.2022.107968.

6.     Zeiders SM, Chmielewski J. Antibiotic–cell‐penetrating peptide conjugates targeting challenging drug‐resistant and intracellular pathogenic bacteria. Chem Biol Drug Des 2021;98:762–78. https://doi.org/10.1111/cbdd.13930.

7.     Gao X, Ding J, Liao C, Xu J, Liu X, Lu W. Defensins: The natural peptide antibiotic. Adv Drug Deliv Rev 2021;179:114008. https://doi.org/10.1016/j.addr.2021.114008.

8.     Zheng S, Tu Y, Li B, Qu G, Li A, Peng X, et al. Antimicrobial peptide biological activity, delivery systems and clinical translation status and challenges. J Transl Med 2025;23:292. https://doi.org/10.1186/s12967-025-06321-9.

9.     Asar M, Newton-Northup J, Soendergaard M. Improving Pharmacokinetics of Peptides Using Phage Display. Viruses 2024;16:570. https://doi.org/10.3390/v16040570.

10.  Yadav A, Pandey D, Ashraf GMd, Rachana. Peptide Based Therapy for Neurological Disorders. Curr Protein Pept Sci 2021;22:656–65. https://doi.org/10.2174/1389203722666210920151810.

11.  Liu P, Zhang T, Chen Q, Li C, Chu Y, Guo Q, et al. Biomimetic Dendrimer–Peptide Conjugates for Early Multi‐Target Therapy of Alzheimer’s Disease by Inflammatory Microenvironment Modulation. Advanced Materials 2021;33. https://doi.org/10.1002/adma.202100746.

12.  Mitchell JL, Lyons HS, Walker JK, Yiangou A, Grech O, Alimajstorovic Z, et al. The effect of GLP-1RA exenatide on idiopathic intracranial hypertension: a randomized clinical trial. Brain 2023;146:1821–30. https://doi.org/10.1093/brain/awad003.

13.  Herrera-Barrera M, Ryals RC, Gautam M, Jozic A, Landry M, Korzun T, et al. Peptide-guided lipid nanoparticles deliver mRNA to the neural retina of rodents and nonhuman primates. Sci Adv 2023;9. https://doi.org/10.1126/sciadv.add4623.

14.  Tomašević N, Emser FS, Muratspahić E, Gattringer J, Hasinger S, Hellinger R, et al. Discovery and development of macrocyclic peptide modulators of the cannabinoid 2 receptor. Journal of Biological Chemistry 2024;300:107330. https://doi.org/10.1016/j.jbc.2024.107330.

15.  Vaida V, Deal AM. Peptide synthesis in aqueous microdroplets. Proceedings of the National Academy of Sciences 2022;119. https://doi.org/10.1073/pnas.2216015119.

16.  Hu Y-X, Liu Z, Zhang Z, Deng Z, Huang Z, Feng T, et al. Antihepatoma peptide, scolopentide, derived from the centipede scolopendra subspinipes mutilans. World J Gastroenterol 2023;29:1875–98. https://doi.org/10.3748/wjg.v29.i12.1875.

17.  Wang W, Liu Z, Liu Y, Su Z, Liu Y. Plant polypeptides: A review on extraction, isolation, bioactivities and prospects. Int J Biol Macromol 2022;207:169–78. https://doi.org/10.1016/j.ijbiomac.2022.03.009.

18.  Wang W, Liu Z, Liu Y, Su Z, Liu Y. Plant polypeptides: A review on extraction, isolation, bioactivities and prospects. Int J Biol Macromol 2022;207:169–78. https://doi.org/10.1016/j.ijbiomac.2022.03.009.

19.  Mudgil P, Baba WN, Kamal H, FitzGerald RJ, Hassan HM, Ayoub MA, et al. A comparative investigation into novel cholesterol esterase and pancreatic lipase inhibitory peptides from cow and camel casein hydrolysates generated upon enzymatic hydrolysis and in-vitro digestion. Food Chem 2022;367:130661. https://doi.org/10.1016/j.foodchem.2021.130661.

20.  Ruth DM, McMahon G, Ó’Fágáin C. Peptide synthesis by recombinant Fasciola hepatica cathepsin L1. Biochimie 2006;88:117–20. https://doi.org/10.1016/j.biochi.2005.06.004.

21.  Dohan Ehrenfest DM, Pinto NR, Pereda A, Jiménez P, Corso M Del, Kang B-S, et al. The impact of the centrifuge characteristics and centrifugation protocols on the cells, growth factors, and fibrin architecture of a leukocyte- and platelet-rich fibrin (L-PRF) clot and membrane. Platelets 2018;29:171–84. https://doi.org/10.1080/09537104.2017.1293812.

22.  Josic D, Kovac S. Reversed‐Phase High Performance Liquid Chromatography of Proteins. Curr Protoc Protein Sci 2010;61. https://doi.org/10.1002/0471140864.ps0807s61.

23.  Zhang G, Annan RS, Carr SA, Neubert TA. Overview of Peptide and Protein Analysis by Mass Spectrometry. Curr Protoc Protein Sci 2010;62. https://doi.org/10.1002/0471140864.ps1601s62.

24.  Adamski Z, Bufo SA, Milella L, Scrano L. Identification and Functional Characterization of Plant Toxins. Toxins (Basel) 2021;13:228. https://doi.org/10.3390/toxins13030228.

25.  Androphy EJ, Hubbert NL, Schiller JT, Lowy DR. Identification of the HPV-16 E6 protein from transformed mouse cells and human cervical carcinoma cell lines. EMBO J 1987;6:989–92. https://doi.org/10.1002/j.1460-2075.1987.tb04849.x.

26.  Bistaffa E, Rossi M, De Luca CMG, Moda F. Biosafety of Prions, 2017, p. 455–85. https://doi.org/10.1016/bs.pmbts.2017.06.017.

27.  Wickner RB. Yeast and Fungal Prions. Cold Spring Harb Perspect Biol 2016;8:a023531. https://doi.org/10.1101/cshperspect.a023531.

28.  Kurt TD, Sigurdson CJ. Cross-species transmission of CWD prions. Prion 2016;10:83–91. https://doi.org/10.1080/19336896.2015.1118603.

29.  Oliveira CS, Torres MDT, Pedron CN, Andrade VB, Silva PI, Silva FD, et al. Synthetic Peptide Derived from Scorpion Venom Displays Minimal Toxicity and Anti-infective Activity in an Animal Model. ACS Infect Dis 2021;7:2736–45. https://doi.org/10.1021/acsinfecdis.1c00261.

30.  Behrendt R, White P, Offer J. Advances in Fmoc solid‐phase peptide synthesis. Journal of Peptide Science 2016;22:4–27. https://doi.org/10.1002/psc.2836.

31.  Pisk J, Agustin D, Poli R. Organic Salts and Merrifield Resin Supported [PM12O40]3− (M = Mo or W) as Catalysts for Adipic Acid Synthesis. Molecules 2019;24:783. https://doi.org/10.3390/molecules24040783.

32.  Tulla-Puche J, Barany G. On-Resin Native Chemical Ligation for Cyclic Peptide Synthesis. J Org Chem 2004;69:4101–7. https://doi.org/10.1021/jo049839d.

33.  Posada L, Serra G. Three Methods for Peptide Cyclization Via Lactamization, 2022, p. 3–17. https://doi.org/10.1007/978-1-0716-1689-5_1.

34.  Behrendt R, White P, Offer J. Advances in Fmoc solid‐phase peptide synthesis. Journal of Peptide Science 2016;22:4–27. https://doi.org/10.1002/psc.2836.

35.  Sabatino G, Papini AM. Advances in automatic, manual and microwave-assisted solid-phase peptide synthesis. Curr Opin Drug Discov Devel 2008;11:762–70.

36.  Yang X, Lin H, Lu W, Wang D. Compatibility Study of Merrifield Linker in Fmoc Strategy Peptide Synthesis. Protein Pept Lett 2013;20:140–5. https://doi.org/10.2174/092986613804725343.

37.  Mäde V, Els-Heindl S, Beck-Sickinger AG. Automated solid-phase peptide synthesis to obtain therapeutic peptides. Beilstein Journal of Organic Chemistry 2014;10:1197–212. https://doi.org/10.3762/bjoc.10.118.

38.  Sharma A, Kumar A, de la Torre BG, Albericio F. Liquid-Phase Peptide Synthesis (LPPS): A Third Wave for the Preparation of Peptides. Chem Rev 2022;122:13516–46. https://doi.org/10.1021/acs.chemrev.2c00132.

39.  Demidova TYu, Ushanova FO, Bogacheva TL. Semaglutide in type 2 diabetes management: review of current evidence from concept to date. FOCUS Endocrinology 2023;4:13–28. https://doi.org/10.15829/2713-0177-2023-3-11.

40.  Fiani B, Covarrubias C, Wong A, Doan T, Reardon T, Nikolaidis D, et al. Cerebrolysin for stroke, neurodegeneration, and traumatic brain injury: review of the literature and outcomes. Neurological Sciences 2021;42:1345–53. https://doi.org/10.1007/s10072-021-05089-2.

41.  V Kalmykova G, Chefranova ZhYu, Rybnikova VF, Zubova KO. Cortexin administration due to improvement of cognitive and behavioral disorders in children and teenagers with epilepsy. Zhurnal Nevrologii i Psikhiatrii Im SS Korsakova 2021;121:127. https://doi.org/10.17116/jnevro2021121031127.

42.  Malakhova AI, Strakhov VV, Kovaleva YD, Malakhova YA. Objective functional monitoring of retinoprotective treatment in diabetic retinopathy. Russian Annals of Ophthalmology 2024;140:45. https://doi.org/10.17116/oftalma202414001145.

43.  Ushkalova EA, Zyryanov SK, Zatolochina KE. Muramyldipeptide - based compounds in current medicine: focus on glucosaminylmuramyl dipeptide. Ter Arkh 2019;91:122–7. https://doi.org/10.26442/00403660.2019.12.000471.

44.  Panikratova YaR, Lebedeva IS, Sokolov OYu, Rumshiskaya AD, Kupriyanov DA, Kost N V., et al. Functional Connectomic Approach to Studying Selank and Semax Effects. Doklady Biological Sciences 2020;490:9–11. https://doi.org/10.1134/S001249662001007X.

45.  de Breij A, Riool M, Cordfunke RA, Malanovic N, de Boer L, Koning RI, et al. The antimicrobial peptide SAAP-148 combats drug-resistant bacteria and biofilms. Sci Transl Med 2018;10. https://doi.org/10.1126/scitranslmed.aan4044.

46.  Khamaganova I V, Akhmedov KB, Tarabrina NP, Khromova SS, Mezentseva M V, Koval’chuk L V, et al. [Effect of combined therapy using complex of natural cytokines and antimicrobial peptides in urogenital infections caused by Chlamydia and Mycoplasma]. Zh Mikrobiol Epidemiol Immunobiol 2011:90–3.

47.  Smits MM, Van Raalte DH. Safety of Semaglutide. Front Endocrinol (Lausanne) 2021;12. https://doi.org/10.3389/fendo.2021.645563.

48.  Lundgren JR, Janus C, Jensen SBK, Juhl CR, Olsen LM, Christensen RM, et al. Healthy Weight Loss Maintenance with Exercise, Liraglutide, or Both Combined. New England Journal of Medicine 2021;384:1719–30. https://doi.org/10.1056/NEJMoa2028198.

49.  Tokarz VL, MacDonald PE, Klip A. The cell biology of systemic insulin function. Journal of Cell Biology 2018;217:2273–89. https://doi.org/10.1083/jcb.201802095.

50.  Gomazkov OA. Cortexin. Molecular mechanisms and targets of neuroprotective activity. Zhurnal Nevrologii i Psikhiatrii Im SS Korsakova 2015;115:99. https://doi.org/10.17116/jnevro20151158199-104.

51.  Suetov AA, Alekperov SI, Odinokaya MA, Kostina AA. Retinoprotective effects of Retinalamin studied in an experimental model of photochemical damage to rabbit retinas. Vestn Oftalmol 2021;137:57. https://doi.org/10.17116/oftalma202113705157.

52.  Trofimova S V, Linkova NS, Klimenko AA, Kvetnaia T V, Khavinson VK. [Pineamin increased pineal melatonin synthesis in elderly people]. Adv Gerontol 2017;30:422–6.

53.  Latyshev OE, Zaykova ON, Eliseeva O V., Savochkina TE, Chernoryzh YYu, Syroeshkin A V., et al. Development, production and characterization of SARS-CoV-2 virus-like particles (Coronaviridae: Orthocoronavirinae: Betacoronavirus: Sarbecovirus). Probl Virol 2024;69:175–86. https://doi.org/10.36233/0507-4088-226.

54.  Timms RT, Zhang Z, Rhee DY, Harper JW, Koren I, Elledge SJ. A glycine-specific N-degron pathway mediates the quality control of protein N-myristoylation. Science (1979) 2019;365. https://doi.org/10.1126/science.aaw4912.

55.  Selivanova OM, Grishin SYu, Glyakina A V., Sadgyan AS, Ushakova NI, Galzitskaya O V. Analysis of Insulin Analogs and the Strategy of Their Further Development. Biochemistry (Moscow) 2018;83:S146–62. https://doi.org/10.1134/S0006297918140122.

56.  Maikawa CL, Nguyen LT, Mann JL, Appel EA. Formulation Excipients and Their Role in Insulin Stability and Association State in Formulation. Pharm Res 2022;39:2721–8. https://doi.org/10.1007/s11095-022-03367-y.

57.  Deacon CF. Peptide degradation and the role of DPP-4 inhibitors in the treatment of type 2 diabetes. Peptides (NY) 2018;100:150–7. https://doi.org/10.1016/j.peptides.2017.10.011.

58.  Griffiths RC, Smith FR, Li D, Wyatt J, Rogers DM, Long JE, et al. Cysteine‐Selective Modification of Peptides and Proteins via Desulfurative C−C Bond Formation. Chemistry – A European Journal 2023;29. https://doi.org/10.1002/chem.202202503.

59.  Liu Y, Lu X, Chen M, Wei Z, Peng G, Yang J, et al. Advances in screening, synthesis, modification, and biomedical applications of peptides and peptide aptamers. BioFactors 2024;50:33–57. https://doi.org/10.1002/biof.2001.

60.  Yao C, Ye G, Yang Q, Chen Z, Yang M. The Disulfide Bond-Mediated Cyclization of Oral Peptides. Curr Protein Pept Sci 2024;25:438–42. https://doi.org/10.2174/0113892037280719231214095428.

61.  Choi MS, Lee CY, Kim JH, Lee YM, Lee S, Kim HJ, et al. Gramicidin, a Bactericidal Antibiotic, Is an Antiproliferative Agent for Ovarian Cancer Cells. Medicina (B Aires) 2023;59:2059. https://doi.org/10.3390/medicina59122059.

62.  Burkin A V., Svistushkin VM, Nikiforova GN, Dukhanin AS. Glucosaminylmuramyl dipeptide in treatment of respiratory tract diseases. Vestn Otorinolaringol 2019;84:118. https://doi.org/10.17116/otorino201984061118.

63.  Tamura K, Ono M, Kawabe T, Yonemochi E. Impact of Magnesium Stearate Content: Modeling of Drug Degradation Using a Modified Arrhenius Equation. Chem Pharm Bull (Tokyo) 2020;68:1049–54. https://doi.org/10.1248/cpb.c20-00443.

64.  Skibska A, Perlikowska R. Signal Peptides - Promising Ingredients in Cosmetics. Curr Protein Pept Sci 2021;22:716–28. https://doi.org/10.2174/1389203722666210812121129.

65.  Apostolopoulos V, Bojarska J, Chai T-T, Elnagdy S, Kaczmarek K, Matsoukas J, et al. A Global Review on Short Peptides: Frontiers and Perspectives. Molecules 2021;26:430. https://doi.org/10.3390/molecules26020430.

66.  Gan P-Y, Tan DSY, Ooi JD, Alikhan MA, Kitching AR, Holdsworth SR. Myeloperoxidase Peptide–Based Nasal Tolerance in Experimental ANCA–Associated GN. Journal of the American Society of Nephrology 2016;27:385–91. https://doi.org/10.1681/ASN.2015010089.

67.  Lebedeva IS, Panikratova YaR, Sokolov OYu, Kupriyanov DA, Rumshiskaya AD, Kost N V., et al. Effects of Semax on the Default Mode Network of the Brain. Bull Exp Biol Med 2018;165:653–6. https://doi.org/10.1007/s10517-018-4234-3.

68.  Leonidovna YA, Aleksandrovna SM, Aleksandrovna TA, Aleksandrovna BO, Fedorovich MN, Aleksandrovna AL. The Influence of Selank on the Level of Cytokines Under the Conditions of “Social” Stress. Current Reviews in Clinical and Experimental Pharmacology 2021;16:162–7. https://doi.org/10.2174/1574884715666200704152810.

69.  Pestka S, Krause CD, Walter MR. Interferons, interferon‐like cytokines, and their receptors. Immunol Rev 2004;202:8–32. https://doi.org/10.1111/j.0105-2896.2004.00204.x.

70.  Ham AS, Buckheit RW. Designing and Developing Suppository Formulations for anti-HIV Drug Delivery. Ther Deliv 2017;8:805–17. https://doi.org/10.4155/tde-2017-0056.

71.  Korneev IAK. Russian experience with Vitaprost Forte suppositories in patients with lower urinary tract symptoms and benign prostatic hyperplasia: comparative analysis of studies. Urologiia 2017;3_2017:138–44. https://doi.org/10.18565/urol.2017.3.138-144.

72.  Wang L, Hu Z, Chen J, Wang T, Wu P, Ying Y. Simultaneous Determination of 12 Preservatives in Pastries Using Gas Chromatography–Mass Spectrometry. Foods 2023;12:3819. https://doi.org/10.3390/foods12203819.

73.  Sinha NJ, Langenstein MG, Pochan DJ, Kloxin CJ, Saven JG. Peptide Design and Self-assembly into Targeted Nanostructure and Functional Materials. Chem Rev 2021;121:13915–35. https://doi.org/10.1021/acs.chemrev.1c00712.

74.  Pei Z, Song Q, Xu J, Yu S, Ma H. The Cyclic Antimicrobial Peptide C-LR18 Has Enhanced Antibacterial Activity, Improved Stability, and a Longer Half-Life Compared to the Original Peptide. Antibiotics 2025;14:312. https://doi.org/10.3390/antibiotics14030312.

75.  Moiola M, Memeo MG, Quadrelli P. Stapled Peptides—A Useful Improvement for Peptide-Based Drugs. Molecules 2019;24:3654. https://doi.org/10.3390/molecules24203654.

76.  Meng Y, Li XJ, Li Y, Zhang TY, Liu D, Wu YQ, et al. Novel Double-Layer Dissolving Microneedles for Transmucosal Sequential Delivery of Multiple Drugs in the Treatment of Oral Mucosa Diseases. ACS Appl Mater Interfaces 2023. https://doi.org/10.1021/acsami.2c19913.

77.  Bruun TUJ, Andersson A-MC, Draper SJ, Howarth M. Engineering a Rugged Nanoscaffold To Enhance Plug-and-Display Vaccination. ACS Nano 2018;12:8855–66. https://doi.org/10.1021/acsnano.8b02805.

78.  Zhang B, Sun X, Mei H, Wang Y, Liao Z, Chen J, et al. LDLR-mediated peptide-22-conjugated nanoparticles for dual-targeting therapy of brain glioma. Biomaterials 2013;34:9171–82. https://doi.org/10.1016/j.biomaterials.2013.08.039.

79.  Martins S, Sarmento B, Ferreira DC, Souto EB. Lipid-based colloidal carriers for peptide and protein delivery--liposomes versus lipid nanoparticles. Int J Nanomedicine 2007;2:595–607.

80.  Haddadzadegan S, Dorkoosh F, Bernkop-Schnürch A. Oral delivery of therapeutic peptides and proteins: Technology landscape of lipid-based nanocarriers. Adv Drug Deliv Rev 2022;182:114097. https://doi.org/10.1016/j.addr.2021.114097.

81.  Bezir K, Pelit Arayici P, Akgül B, Abamor EŞ, Acar S. RABV antigenic peptide loaded polymeric nanoparticle production, characterization, and preliminary investigation of its biological activity. Nanotechnology 2025;36:025603. https://doi.org/10.1088/1361-6528/ad84fe.

82.  Mikolajczak DJ, Berger AA, Koksch B. Catalytically Active Peptide–Gold Nanoparticle Conjugates: Prospecting for Artificial Enzymes. Angewandte Chemie International Edition 2020;59:8776–85. https://doi.org/10.1002/anie.201908625.

83.  Dragulska SA, Santiago MA, Poursharifi M, Mieszawska AJ. Peptide-Coated Nanoparticles for Noninvasive Biomedical Imaging, 2025, p. 37–53. https://doi.org/10.1007/978-1-0716-4402-7_3.

84.  Moradian A, Goonatilleke E, Lin T-T, Hatten-Beck M, Emrick M, Schepmoes AA, et al. Interlaboratory Comparison of Antibody-Free LC-MS/MS Measurements of C-peptide and Insulin. Clin Chem 2024;70:855–64. https://doi.org/10.1093/clinchem/hvae034.

85.  Scrosati PM, Konermann L. Atomistic Details of Peptide Reversed-Phase Liquid Chromatography from Molecular Dynamics Simulations. Anal Chem 2023;95:3892–900. https://doi.org/10.1021/acs.analchem.2c05667.

86.  Von Bahr-Lindstróm H, Moberg U, Sjódahl J, Jórnvall H. Ion-exchange high-performance liquid-chromatography steps in peptide purifications. Biosci Rep 1982;2:803–11. https://doi.org/10.1007/BF01114940.

87.  Treblin M, von Oesen T, Class L-C, Kuhnen G, Clawin-Rädecker I, Martin D, et al. Two-dimensional high-performance thin-layer chromatography for the characterization of milk peptide properties and a prediction of the retention behavior – a proof-of-principle study. J Chromatogr A 2021;1653:462442. https://doi.org/10.1016/j.chroma.2021.462442.

88.  Huang Q, Gao Q, Chai X, Ren W, Zhang G, Kong Y, et al. A novel thrombin inhibitory peptide discovered from leech using affinity chromatography combined with ultra-high performance liquid chromatography-high resolution mass spectroscopy. Journal of Chromatography B 2020;1151:122153. https://doi.org/10.1016/j.jchromb.2020.122153.

89.  Lohr J, Baukmann S, Block J, Upmann M, Spieß AC. Understanding adsorption behavior of antiviral labyrinthopeptin peptides in anion exchange chromatography. J Chromatogr A 2023;1690:463792. https://doi.org/10.1016/j.chroma.2023.463792.

90.  Weiß F, Schnabel A, Planatscher H, van den Berg BHJ, Serschnitzki B, Nuessler AK, et al. Indirect protein quantification of drug-transforming enzymes using peptide group-specific immunoaffinity enrichment and mass spectrometry. Sci Rep 2015;5:8759. https://doi.org/10.1038/srep08759.

91.  Nag B, Mukku P V., Arimilli S, Kendrick T, Deshpande S V., Sharma SD. Separation of complexes of major histocompatibility class II molecules and known antigenic peptide by metal chelate affinity chromatography. J Immunol Methods 1994;169:273–85. https://doi.org/10.1016/0022-1759(94)90271-2.

92.  Nika H, Nieves E, Hawke DH, Angeletti RH. Phosphopeptide Enrichment by Covalent Chromatography after Derivatization of Protein Digests Immobilized on Reversed-Phase Supports. J Biomol Tech 2013;24:154–77. https://doi.org/10.7171/jbt.13-2403-004.

93.  Cheung MY, Bruce J, Euerby MR, Field JK, Petersson P. Investigation into reversed-phase chromatography peptide separation systems part V: Establishment of a screening strategy for development of methods for assessment of pharmaceutical peptides’ purity. J Chromatogr A 2022;1668:462888. https://doi.org/10.1016/j.chroma.2022.462888.

94.  Xia Z, Liu Z, Kong F, Fan L, Xiao H, Cao C. Comparison of antimicrobial peptide purification via free‐flow electrophoresis and gel filtration chromatography. Electrophoresis 2017;38:3147–54. https://doi.org/10.1002/elps.201700187.

95.  Kielkopf CL, Bauer W, Urbatsch IL. Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis of Proteins. Cold Spring Harb Protoc 2021;2021:pdb.prot102228. https://doi.org/10.1101/pdb.prot102228.

96.  Kong F, Zhang M, Chen J, Fan L, Xiao H, Liu S, et al. Continuous protein concentration via free-flow moving reaction boundary electrophoresis. J Chromatogr A 2017;1508:169–75. https://doi.org/10.1016/j.chroma.2017.06.008.

97.  Abildgaard U. Highly Purified Antithrombin III with Heparin Cofactor Activity Prepared by Disc Electrophoresis. Scand J Clin Lab Invest 1968;21:89–91. https://doi.org/10.3109/00365516809076981.

98.  Kašička V, Prusík Z. Application of capillary isotachophoresis in peptide analysis. J Chromatogr B Biomed Sci Appl 1991;569:123–74. https://doi.org/10.1016/0378-4347(91)80228-5.

99.  Hallin P, Renlund S. Evaluation of several strategies for preparing a bovine gonadotropin-like peptide using isotachophoresis, isoelectrofocusing and high-performance liquid chromatography. J Chromatogr A 1986;363:251–60. https://doi.org/10.1016/S0021-9673(01)83744-4.

100.    Li Y, Ren D. Two-Dimensional Gel Electrophoresis and Pro-Q Diamond Phosphoprotein Stain-Based Plant Phosphoproteomics, 2021, p. 159–68. https://doi.org/10.1007/978-1-0716-1625-3_11.

101.    Friedman M. Applications of the Ninhydrin Reaction for Analysis of Amino Acids, Peptides, and Proteins to Agricultural and Biomedical Sciences. J Agric Food Chem 2004;52:385–406. https://doi.org/10.1021/jf030490p.

102. Kokona B, Winesett ES, Nikolai von Krusenstiern A, Cryle MJ, Fairman R, Charkoudian LK. Probing the selectivity of β-hydroxylation reactions in non-ribosomal peptide synthesis using analytical ultracentrifugation. Anal Biochem 2016;495:42–51. https://doi.org/10.1016/j.ab.2015.11.011.

103.    Cardoso Mendes Moura EC, Polissi A, Sperandeo P. Membrane Fractionation by Isopycnic Sucrose Density Gradient Centrifugation for Qualitative Analysis of LPS in Escherichia coli, 2022, p. 53–69. https://doi.org/10.1007/978-1-0716-2581-1_4.

104.    Zhang G, Annan RS, Carr SA, Neubert TA. Overview of Peptide and Protein Analysis by Mass Spectrometry. Curr Protoc Protein Sci 2010;62. https://doi.org/10.1002/0471140864.ps1601s62.

105.    Villegas JA, Sinha NJ, Teramoto N, Von Bargen CD, Pochan DJ, Saven JG. Computational Design of Single-Peptide Nanocages with Nanoparticle Templating. Molecules 2022;27:1237. https://doi.org/10.3390/molecules27041237.

106. Takadi T. Confirmation of Molecular Weight of Aspergillus oryzae α-Amylase Using the Low Angle Laser Light Scattering Technique in Combination with High Pressure Silica Gel Chromatography1. The Journal of Biochemistry 1981;89:363–8. https://doi.org/10.1093/oxfordjournals.jbchem.a133210.

107. Odnovorov AI, Grebennikova Т V., Pleteneva T V., Garaev TM, Uspenskaya E V., Khodorovich NA, et al. Physicochemical Properties and Biological Activity of The New Antiviral Substance. International Journal of Applied Pharmaceutics 2020:237–42. https://doi.org/10.22159/ijap.2020v12i4.38136.

108. Saraiva MA. Interpretation of α-synuclein UV absorption spectra in the peptide bond and the aromatic regions. J Photochem Photobiol B 2020;212:112022. https://doi.org/10.1016/j.jphotobiol.2020.112022.

109.    Patrick AL, Polfer NC. Peptide Fragmentation Products in Mass Spectrometry Probed by Infrared Spectroscopy, 2014, p. 153–81. https://doi.org/10.1007/128_2014_576.

110.    Syroeshkin A V., Petrov G V., Taranov V V., Pleteneva T V., Koldina AM, Gaydashev IA, et al. Radiothermal Emission of Nanoparticles with a Complex Shape as a Tool for the Quality Control of Pharmaceuticals Containing Biologically Active Nanoparticles. Pharmaceutics 2023;15:966. https://doi.org/10.3390/pharmaceutics15030966.

111.    Petrov G V., Galkina DA, Koldina AM, Grebennikova T V., Eliseeva O V., Chernoryzh YYu, et al. Controlling the Quality of Nanodrugs According to Their New Property—Radiothermal Emission. Pharmaceutics 2024;16:180. https://doi.org/10.3390/pharmaceutics16020180.

112.    Petrov G V., Gaidashev IA, Syroeshkin A V. Physical and Chemical Characteristics of Aqueous Colloidal Infusions of Medicinal Plants Containing Humic Acids. International Journal of Applied Pharmaceutics 2024:76–82. https://doi.org/10.22159/ijap.2024v16i1.49339.

113. Petrov G, Syroeshkin AV. Express Method for Quality Control of Products after the Fluidized Bed Aerosol Chamber by Detecting Radio Thermal Emission of Nanoparticles. European Chemical Bulletin 2023;12. https://doi.org/10.48047/ecb/2023.12.6.273.

114. Petrov G V., Koldina AM, Ledenev O V., Tumasov VN, Nazarov AA, Syroeshkin A V. Nanoparticles and Nanomaterials: A Review from the Standpoint of Pharmacy and Medicine. Pharmaceutics 2025;17:655. https://doi.org/10.3390/pharmaceutics17050655.