Seekers of eternal youth are documented as far back as the 5th century B.C. when Herodotus famously described a mystical fountain that restored youth to those who drank and bathed in its waters. While the mysterious fountain of youth remains to be found, scientists are hard at work finding new ways to slow down the visible signs of time. Of particular interest is the development of skincare that fends off “photoaging” or skin damage produced after prolonged sun exposure. Broad spectrum sunscreen is the first line of defense against harmful UV rays. However, according to the American Academy of Dermatology most people only apply between 25-50% of the amount of sunscreen recommended. Without proper application of sunscreen, some harmful UV rays penetrate the skin. This contributes to an increased amount of free radicals which damages skin cells and fibers. Overtime, the free radical damage becomes visually apparent and results in deep wrinkles, sagging, dark spots and even skin cancer (see picture).
How do we neutralize free radicals on the skin?
Lucky for us, our bodies already produce very effective molecules that neutralize free radicals in the body, these molecules are called antioxidants. Aging depletes the antioxidant defenses in the body, and as such the use of topical antioxidants is of particular interest. Nowadays, antioxidants are a staple ingredient in many skincare products, including sunscreen. The top natural antioxidants you will find in moisturizers and serums include vitamin C, retinol (vitamin A), α-tocopherol (vitamin E), resveratrol, polyphenols, and flavonoids often extracted from fruits and plants.
Well, while in theory these creams could minimize the effects of photoaging, the truth is that manufacturing antioxidant-containing skincare is a complex process. For starters, many commercialized antioxidants like vitamin C are very unstable and break down when exposed to body heat, air, and/or light. Additionally, a number of antioxidants fail to penetrate the skin, thus limiting the antioxidant options for topical use.
How do we fix that?
Nanoparticles have allowed scientists to create tiny mesh like balls, about 1,000,000 times smaller than the head of a pin, to protect antioxidants from rapid break down after skin contact. Recently, investigators from Università di Torino, in Italy, published an article in the International Journal of Pharmaceutics, detailing the synthesis of heat-responsive nanoparticles filled with a common plant flavonoid, quercetin, for skin topical application. Scientists found that quercetin-loaded nanoparticles were able to show a modest increase in antioxidant absorption by the skin. Even more exciting, the nanoparticle increased the free radical neutralizing effect of the antioxidant. Other studies employing a diversity of nanoparticles and antioxidants reveal similar results to those coming from Italy, all of which show that skin protection through topical nanoparticle containing antioxidants is achievable.
Though the mystical fountain of youth may never be found, scientists seem to be on the verge of uncovering the remedy to slow down the visible signs of aging through antioxidant nanoparticle-based creams.
Peer edited by Sean Gay
Watu wanaotafuta ujana wa milele walianza kuonekana katika karne ya 5 KK. Herodoto alieleza kuhusu chemchemi ya maji ambayo iliwapa vijana wale waliokunywa maji yake. Ingawa chemchemi ya ujana bado haijapatikana, wanasayansi wanajitahidi kutafuta njia mpya za kupunguza ishara za wakati. Jambo la kupendeza hasa ni maendeleo ya utunzaji wa ngozi ambayo hupinga "kuzeeka kwa picha" au uharibifu wa ngozi unaotokana na kuathiriwa kwa muda mrefu na jua. Kinga ya jua ya wigo mkubwa ni njia ya kwanza ya kujikinga na miale ya UV yenye madhara. Kulingana na Chuo cha Amerika cha Dermatolojia, watu wengi hutumia tu kati ya 25% na 50% ya kiasi cha kinga ya jua inayopendekezwa. Bila kutumia krimu ya kujikinga na jua ifaavyo, baadhi ya miale ya UV yenye kudhuru huingia kwenye ngozi. Hii inachangia kuongezeka kwa kiasi cha free radicals ambayo kuharibu seli ngozi na nyuzi. Baada ya muda, uharibifu wa free radical unakuwa dhahiri na matokeo katika wrinkles kina, sagging, spots giza na hata kansa ya ngozi (tazama picha). Tunaharibuje madini ya bure kwenye ngozi? Kwa bahati nzuri, miili yetu tayari inazalisha molekuli zenye ufanisi sana ambazo zinazuia free radicals katika mwili, molekuli hizi huitwa antioxidants. Kuzeeka huondoa ulinzi wa antioxidant katika mwili, na kama vile matumizi ya antioxidants ya ndani ni ya maslahi maalum. Leo, viuavijasumu ni sehemu muhimu ya bidhaa nyingi za kutunza ngozi, kutia ndani dawa za kujikinga na jua. Vipengele vya juu vya antioxidant vya asili ambavyo unaweza kupata katika moisturizers na serums ni pamoja na vitamini C, retinol (vitamini A), α-tocopherol (vitamini E), resveratrol, polyphenols, na flavonoids mara nyingi hutolewa kutoka kwa matunda na mimea. Ingawa, kwa nadharia, krimu hizi zinaweza kupunguza athari za kuzeeka kwa picha, ukweli ni kwamba utengenezaji wa dawa za kunyoa ngozi zenye antioxidants ni mchakato tata. Kwa ajili ya kuanza, wengi antioxidants kibiashara kama vitamini C ni imara sana na kuvunjika chini wakati kufunuliwa kwa joto la mwili, hewa, na au mwanga. Kwa kuongezea, antioxidants kadhaa hushindwa kupenya ngozi, hivyo kupunguza chaguzi za antioxidant kwa matumizi ya ndani. Twaweza kurekebishaje jambo hilo? Nanoparticles ni chombo cha kisasa cha kutengeneza nyuzi ndogo za nyuzi, mara milioni moja ndogo kuliko kichwa cha pini, ili kulinda antioxidants kutoka kwa kuvunjika haraka baada ya kuwasiliana na ngozi. Watafiti kutoka Chuo Kikuu cha Turin nchini Italia wamechapisha makala katika jarida la International Journal of Pharmaceutics, inayoelezea jinsi nanoparticles zinazojibu joto zimejazwa na flavonoid ya kawaida ya mmea, quercetin, kwa matumizi ya ngozi. Kwa mfano, wanasayansi walipata kwamba nanoparticles zenye quercetin zina uwezo wa kuongeza kiasi kidogo cha antioxidant katika ngozi. Jambo lenye kusisimua hata zaidi ni kwamba, chembechembe hizo za nanoparticle ziliongeza uwezo wa kiuavijasumu wa kuzuia viini vya free radical. Uchunguzi mwingine unaotumia nanoparticles mbalimbali na antioxidants unaonyesha matokeo sawa na yale yanayokuja kutoka Italia, ambayo yote yanaonyesha kwamba ulinzi wa ngozi kupitia nanoparticles ya ndani yenye antioxidants inawezekana. Ingawa chemchemi ya ujana ya ajabu inaweza kamwe kupatikana, wanasayansi wanaonekana kuwa karibu kugundua tiba ya kupunguza dalili za kuzeeka kupitia krimu za nanoparticles za antioxidant. Peer ilihaririwa na Sean Gay