20.500.12556/RUL-187502 Pregled kliničnih študij učinkov kolagena na kožo in njegove zastopanosti v kozmetičnih izdelkih Review of clinical studies considering the collagen skin effects and its presence in cosmetic products Kolagen je osnovni strukturni protein zunajceličnega matriksa usnjice. Kolagenska vlakna so viskoelastičen material z visoko natezno trdnostjo in nizko prožnostjo, ki koži zagotavljajo podporno ogrodje in mehansko zaščito. S staranjem in pod vplivom UV- sevanja se zmanjšuje aktivnost fibroblastov in s tem biosinteza kolagena, spreminjata pa se tudi njegova struktura in prostorska ureditev znotraj usnjice, ki se tanjša. Tkivo izgublja elastičnost in čvrstost, kar se kaže kot nagubana in ohlapna koža. Različne oblike kolagena, predvsem živalskega ali biotehnološkega izvora, se zato vse pogosteje uporabljajo v kozmetičnih in nutrikozmetičnih izdelkih, namenjenih predvsem negi zrele in fotostarane kože. Ker molekulska masa nativnega kolagena onemogoča njegovo prehajanje skozi roženo plast, se zlasti v dermalne izdelke vgrajujejo predvsem hidroliziran kolagen ali peptidi z nižjo molekulsko maso, ki izkazujejo tudi boljše tehnološke lastnosti in jih je lažje vgraditi v različne formulacije. V okviru diplomske naloge smo celostno pregledali novejše klinične študije, ki so proučevale učinek dermalno in peroralno apliciranega kolagena na izbrane parametre kože, predvsem na hidratiranost in barierno funkcijo kože, njene biomehanske lastnosti ter relief in izraženost gub. Rezultati študij kažejo, da lahko dermalna in peroralna uporaba kolagena ugodno vplivata na hidratacijo, barierno funkcijo, biomehanske lastnosti ter relief kože. V šestih študijah dermalne uporabe izdelkov zlasti s hidroliziranim kolagenom, navajajo izboljšanje hidratacije, zmanjšanje TEWL in hrapavosti ter manjšo izraženost gub. Ker so učinki odvisni tudi od sestave in tehnološke oblike formulacij, so dokazi o samostojnem učinku dermalnega kolagena omejeni, zato so potrebne dodatne tudi metodološko bolj kakovostne študije. Učinke peroralne uporabe, zlasti hidroliziranega kolagena in kolagenskih peptidov, so ustrezno preučevali v petih randomiziranih, dvojno slepih študijah, od katerih so bile štiri s placebom nadzorovane. Večtedensko uživanje je bilo povezano z izboljšano hidracijo in elastičnostjo kože, zmanjšano izraženostjo gub ter povečano gostoto kolagena v usnjici. Tudi v tem primeru pa učinkov ni vedno mogoče pripisati izključno kolagenu, saj nanje vplivajo tudi lastnosti peptidov in sestava formulacij. Pregled nabora izdelkov s kolagenom na tržišču je pokazal široko ponudbo, pri čemer so kozmetični izdelki pogosteje zastopani v drogerijah, nutrikozmetični pa v spletnih lekarnah. Izbrani izdelki so večinoma vsebovali hidroliziran kolagen. Med dermalnimi izdelki so prevladovale kreme za obraz, serumi in maske, trženjske navedbe pa se večinoma nanašajo na učinke vlaženja, zmanjševanje videza gub ter izboljšanje čvrstosti kože. Collagen is the primary structural protein in the dermal extracellular matrix. Its fibers provide tensile strength and mechanical support but have low elasticity. Aging and UV radiation reduce fibroblast activity and collagen biosynthesis while altering collagen structure and organization as the dermis thins. Consequently, the skin loses elasticity and firmness, resulting in wrinkles and sagging. Collagen of animal and biotechnological origin is therefore increasingly used in cosmetic and nutricosmetic products for mature and photoaged skin. Because native collagen cannot penetrate the stratum corneum owing to its high molecular weight, dermal products generally contain hydrolyzed collagen or lower- molecular-weight peptides, which also have better technological properties and are easier to incorporate into formulations. This thesis reviewed recent clinical studies on the effects of dermal and oral collagen administration on skin hydration and barrier function, biomechanical properties, and wrinkle appearance and severity. The results indicate that both administration routes may improve skin hydration, barrier function, biomechanical properties, and skin texture. Six studies of dermal products containing primarily hydrolyzed collagen reported improved hydration, reduced transepidermal water loss (TEWL) and roughness, and less pronounced wrinkles. However, because the effects depend on product composition and formulation technology, evidence for the standalone effects of dermal collagen remains limited, and further methodologically robust studies are needed. Oral administration, particularly of hydrolyzed collagen and collagen peptides, was adequately investigated in five randomized, double-blind studies, four of which were placebo-controlled. Several weeks of use were associated with improved skin hydration and elasticity, reduced wrinkle appearance, and increased dermal collagen density. Nevertheless, these effects cannot always be attributed exclusively to collagen, as they are also influenced by peptide properties and formulation composition. A review of collagen- containing products revealed a wide variety, with cosmetic products mainly available in drugstores and nutricosmetics in online pharmacies. Most selected products contained hydrolyzed collagen. Dermal products were predominantly face creams, serums, and masks, with marketing claims focused on moisturizing, reducing wrinkle appearance, and improving skin firmness. kolagen koža kozmetični izdelki vrednotenje učinki collagen skin cosmetic products evaluation effects true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-09-11 08:45:46 2026-09-11 08:45:51 2026-09-13 03:31:15 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1970-01-01 128692 33933.pdf 33933.pdf 1 D6C74A83A6E74078257C32AE5CBCA41A 6ac79f31f53c0b360f851cb3ff11d02fb9726a4c7eea98d4cd88d81bef1df3c6 6754b1ab-adac-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=247145 Fakulteta za farmacijo 0 0 0