Researchers have devised a new technology that may soon enable women to “self-administer long-acting contraceptives” in a matter of seconds.
The most popular contraceptive methods are the pill, with 28 percent of women using it, and female sterilization, with 27 percent.
The birth control pill is effective in the short term, but more and more women are opting for long-acting methods, such as intrauterine devices and implants.
Currently, such long-acting means of contraception require a healthcare professional to administer them, but new research may bring the benefits of long-acting contraception in a much more accessible form.
Researchers led by Wei Li, a postdoctoral researcher at the Georgia Institute of Technology in Atlanta, devised an innovative technology that would deliver the contraceptive levonorgestrel through a microneedle skin patch.
Mark Prausnitz, a Regents’ Professor in the School of Chemical and Biomolecular Engineering at Georgia Tech, is the corresponding author of the paper, which they have
For their contraceptive method, Li and colleagues used microneedle skin patch technology, which scientists have already developed for administering vaccines.
The patch has drug-containing microscopic needles that break off after a person applies the patch for a few seconds. The tiny needles then remain just under the skin, releasing the drug.
Li and colleagues molded microscopic air bubbles into the top of the needles to enable them to break. The microneedles, after this modification, are strong enough for an individual to push under the skin but remain weak enough to break when they shift the patch to one side.
After the tiny needles are under the skin, they release the hormone levonorgestrel, which disrupts women’s cycles. The fact that the needles consist of biodegradable polymers helps the release of the hormone.
Specifically, Li and colleagues designed the tiny needles from a mix of biodegradable polymers, such as polylactic-co-glycolic acid and polylactic acid. These acids naturally occur in the body, explain the researchers, and doctors routinely use the polymers in absorbable surgical sutures.
Study co-author Steven Schwendeman, the Ara Paul Professor, and chair of the Department of Pharmaceutical Sciences at the University of Michigan in Ann Arbor, explains the polymer selection process.
“We select polymer materials to meet specific design objectives, such as microneedle strength, biocompatibility, biodegradation and drug release time, and formulation stability,” he says.
“Our team then processes the polymer into microneedles by dissolving the polymer and drug in an organic solvent, molding the shape, and then drying off the solvent to create the microneedles.”
“The polymer matrix, when formed in this way, can slowly and safely release contraceptive hormone for weeks or months when placed in the body,” concludes Prof. Schwendeman.
The researchers successfully tested the patch in rats, meaning that the concentration of levonorgestrel they delivered to the rodents via the skin patch stayed above the threshold that they knew had a contraceptive effect in humans.
However, scientists are aware of the challenges that translating these findings into humans pose.
“We do not yet know how the contraceptive microneedle patches would work in humans,” Prof. Prausnitz says. “[B]ecause microneedles are, by definition, small, there are limits to how much drug can be incorporated into a microneedle patch.”
However, the researcher adds, patches that could deliver the recommended dose of the drug are already available, although scientists have yet to test them.
“Because we are using a well-established contraceptive hormone, we are optimistic that the patch will be an effective contraceptive. We also expect that possible skin irritation at the site of patch application will be minimal, but these expectations need to be verified in clinical trials.”
“There is a lot of interest in providing more options for long-acting contraceptives,” continues Prof. Prausnitz.
“Our goal is for women to be able to self-administer long-acting contraceptives with the microneedle patch that would be applied to the skin for 5 seconds just once a month.”
Prof. Mark Prausnitz
Watafiti wamebuni teknolojia mpya ambayo hivi karibuni inaweza kuwawezesha wanawake "kujipatia dawa za kuzuia mimba zenye athari ya muda mrefu" kwa sekunde chache tu. Njia za kuzuia mimba zinazotumiwa na wanawake ni dawa ya kulevya, ambayo asilimia 28 ya wanawake hutumia, na njia ya uzazi wa wanawake, ambayo asilimia 27 hutumia. Dawa za kuzuia uzazi ni bora kwa muda mfupi, lakini wanawake wengi wanaamua kutumia dawa za muda mrefu kama vile viungo vya ndani ya tumbo la uzazi. Kwa sasa, njia hizo za kuzuia mimba za muda mrefu zinahitaji mtaalamu wa huduma za afya kuitumia, lakini utafiti mpya unaweza kuleta faida za njia za kuzuia mimba za muda mrefu katika namna rahisi zaidi. Watafiti wakiongozwa na Wei Li, mtafiti wa baada ya udaktari katika Taasisi ya Teknolojia ya Georgia huko Atlanta, waliunda teknolojia ya ubunifu ambayo itatoa levonorgestrel ya kuzuia mimba kupitia kifuniko cha ngozi cha micro-needle. Mark Prausnitz, profesa wa Regents katika Shule ya Uhandisi wa Kemikali na Biomolecular katika Chuo Kikuu cha Georgia, ni mwandishi wa karatasi hiyo, ambayo inaelezea jinsi Li na wenzake walivyotumia teknolojia ya patch ya ngozi ya microneedle ambayo wanasayansi tayari wametengeneza kwa ajili ya utoaji wa chanjo. Vipande hivyo vina sindano ndogo zenye dawa ambazo huvunjika baada ya mtu kuviweka kwa sekunde chache. Kisha sindano hizo ndogo-ndogo hubaki chini ya ngozi, zikitoa dawa hiyo. Li na wenzake walifanyiza vifuniko vidogo vya hewa kwenye ncha ya sindano hizo ili viweze kuvunjika. Micro-sugua, baada ya marekebisho haya, ni nguvu ya kutosha kwa mtu kushinikiza chini ya ngozi lakini kubaki dhaifu ya kutosha kuvunja wakati wao kuhamisha patch upande mmoja. Baada ya sindano hizo ndogo-ndogo kuwa chini ya ngozi, hutoa homoni iitwayo levonorgestrel, ambayo huzuia mzunguko wa damu ya wanawake. Ukweli kwamba sindano hizo zina polima zinazoweza kuharibiwa kibiolojia husaidia kutolewa kwa homoni hiyo. Li na wenzake waliunda sindano hizo ndogo kwa kutumia mchanganyiko wa polima zinazoweza kuharibika, kama vile asidi ya polylactic-co-glycolic na asidi ya polylactic. Asidi hizo hutokea katika mwili kwa njia ya asili, na madaktari hutumia polima hizo katika sutures za upasuaji. Steven Schwendeman, Profesa wa Ara Paul na Mwenyekiti wa Idara ya Sayansi ya Dawa katika Chuo Kikuu cha Michigan huko Ann Arbor, anaelezea mchakato wa uteuzi wa polima. "Tunachagua vifaa vya polima ili kukidhi malengo maalum ya kubuni, kama vile nguvu ya microneedle, biocompatibility, biodegradation na muda wa kutolewa kwa dawa, na utulivu wa uundaji", anasema. "Timu yetu kisha mchakato polymer katika microneedles kwa kufuta polymer na dawa katika solvent kikaboni, molding sura, na kisha kukausha mbali solvent kuunda microneedles. ""Matrix polymer, wakati umbo katika njia hii, inaweza polepole na salama kutolewa homoni ya kuzuia mimba kwa wiki au miezi wakati kuwekwa katika mwili, ""Prof Schwendeman alisema." Watafiti walifanikiwa kujaribu patch hiyo kwa panya, ikimaanisha kwamba mkusanyiko wa levonorgestrel waliowapa panya kupitia patch ya ngozi ulibaki juu ya kizingiti ambacho walijua kilikuwa na athari ya kuzuia mimba kwa wanadamu. Hata hivyo, wanasayansi wanajua kwamba ni vigumu sana kutumia matokeo hayo kwa wanadamu. "Hatujui bado jinsi vidonge vya sindano ndogo za kuzuia mimba vinavyofanya kazi kwa wanadamu", Prof. Prausnitz anasema. "Kwa sababu microneedles ni ndogo, kuna mipaka kwa kiasi cha dawa inayoweza kuingizwa katika patch ya microneedle. ""Hata hivyo, mtafiti anaongeza, patches ambazo zinaweza kutoa kipimo kilichopendekezwa cha dawa tayari zinapatikana, ingawa wanasayansi bado hawajazijaribu." <unk>Kwa sababu tunatumia homoni ya kuzuia mimba iliyoanzishwa vizuri, tuna matumaini kwamba kifuniko hicho kitakuwa njia bora ya kuzuia mimba. "Tunatarajia pia kwamba uwezekano wa kuchochea ngozi katika eneo la matumizi ya patch itakuwa ndogo, lakini matarajio haya yanahitaji kuthibitishwa katika majaribio ya kliniki. ""Kuna maslahi mengi katika kutoa chaguzi zaidi kwa dawa za kuzuia mimba za muda mrefu,"" anaendelea Profesa Prausnitz." "Lengo letu ni kuwawezesha wanawake kujipatia dawa za kuzuia mimba zenye athari ya muda mrefu kwa kutumia kitambaa cha sindano ndogo ambacho kitatumika kwenye ngozi kwa sekunde tano mara moja tu kwa mwezi,"" alisema Profesa Mark Prausnitz."