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Ngokuthuthukiswa kwezinto ezintsha ezithambile kakhulu zemishini yezokwelapha kanye nezicelo ze-biomedical, ukucaciswa okuphelele kwezakhiwo zabo ezingokomzimba nemishini kubalulekile futhi kuyinselele.Kusetshenziswe inqubo ye-atomic force microscopy (AFM) nanoindentation eshintshiwe ukuze kubonakale imodulus yendawo ephansi kakhulu ye-lehfilcon entsha ye-biomimetic silicone hydrogel contact lens ehuqwe ngongqimba lwezakhiwo zebhulashi le-polymer enegatsha.Le ndlela ivumela ukuzimisela okunembile kwamaphoyinti okuxhumana ngaphandle kwemiphumela ye-viscous extrusion lapho usondela kuma-polymers egatsha.Ngaphezu kwalokho, kwenza kube nokwenzeka ukunquma izici zemishini yezakhi zebhulashi ngazinye ngaphandle komphumela we-poroelasticity.Lokhu kufezwa ngokukhetha uphenyo lwe-AFM olunomklamo (usayizi wethiphu, ijiyomethri nezinga lasentwasahlobo) olufaneleka ngokukhethekile ukulinganisa izakhiwo zezinto ezithambile namasampula ebhayoloji.Le ndlela ithuthukisa ukuzwela nokunemba kokulinganisa okunembile kwento ethambile kakhulu i-lehfilcon A, enemodulus ephansi kakhulu yokunwebeka endaweni engaphezulu (kufika ku-2 kPa) kanye nokunwebeka okuphakeme kakhulu endaweni yangaphakathi (cishe u-100%). .Imiphumela yocwaningo olungaphezulu ayizange iveze nje kuphela izinto ezingaphezulu ezithambile zelensi ye-lehfilcon A, kodwa futhi yabonisa ukuthi i-modulus yamabhulashi e-polymer enamagatsha yayiqhathaniswa naleyo ye-silicon-hydrogen substrate.Le ndlela yokulinganisa ingaphezulu ingasetshenziswa kwezinye izinto ezithambile namathuluzi ezokwelapha.
Izakhiwo zemishini yezinto eziklanyelwe ukuthintana okuqondile nezicubu eziphilayo zivame ukunqunywa imvelo yezinto eziphilayo.Ukufanisa okuphelele kwalezi zakhiwo zezinto ezibonakalayo kusiza ukufeza izici zomtholampilo ezifunwayo zempahla ngaphandle kokubangela izimpendulo ezimbi zamaselula1,2,3.Ngobuningi bezinto ezilinganayo, ukubonakala kwezakhiwo zemishini kulula ngenxa yokutholakala kwezinqubo ezijwayelekile nezindlela zokuhlola (isb, i-microindentation4,5,6).Kodwa-ke, ezintweni ezithambile kakhulu ezinjengamajeli, ama-hydrogel, ama-biopolymers, amaseli aphilayo, njll., lezi zindlela zokuhlola ngokuvamile azisebenzi ngenxa yemikhawulo yokuxazulula izilinganiso kanye ne-inhomogeneity yezinto ezithile7.Phakathi neminyaka edlule, izindlela zendabuko zokuhlenga zishintshiwe futhi zashintshwa ukuze zibonise ububanzi obubanzi bezinto ezithambile, kodwa izindlela eziningi zisahlushwa ukushiyeka okukhulu okunciphisa ukusetshenziswa kwazo8,9,10,11,12,13.Ukuntuleka kwezindlela zokuhlola ezikhethekile ezingabonisa ngokunembile nangokuthembekile izakhiwo zemishini yezinto ezisetshenziswayo ze-supersoft nezendlalelo ezingaphezulu kunciphisa kakhulu ukusetshenziswa kwazo ezinhlelweni ezihlukahlukene.
Emsebenzini wethu owedlule, sethule ilensi yokuxhumana ye-lehfilcon A (CL), into ethambile eyi-heterogeneous enazo zonke izakhiwo ezithambile ezithathwe emiklameni engase ibe khona ye-biomimetic egqugquzelwe ingaphezulu le-cornea yeso.Le biomaterial yathuthukiswa ngokuxhunyelelwa ungqimba lwe-polymer olunamagatsha, oluxhumene ngokuphambano lwe-poly(2-methacryloyloxyethylphosphorylcholine (MPC)) (PMPC) ku-silicone hydrogel (SiHy) 15 eyenzelwe izisetshenziswa zezokwelapha ezisekelwe kuyo.Le nqubo yokuxhunyelelwa idala ungqimba ngaphezulu ohlanganisa ukwakheka kwebhulashi le-polymeric elithambile kakhulu futhi elinwebeka kakhulu.Umsebenzi wethu wangaphambilini ukuqinisekisile ukuthi isakhiwo se-biomimetic se-lehfilcon A CL sinikeza izindawo eziphezulu eziphezulu ezifana nokumanzisa okuthuthukisiwe nokuvimbela ukungcola, ukugcoba okukhulayo, nokunciphisa iseli nokunamathela kwebhaktheriya15,16.Ngaphezu kwalokho, ukusetshenziswa nokuthuthukiswa kwalesi sici se-biomimetic kuphakamisa ukunwetshwa okwengeziwe kwamanye amadivaysi e-biomedical.Ngakho-ke, kubalulekile ukuveza izici ezingaphezulu zale nto ethambile kakhulu futhi uqonde ukusebenzisana kwayo kwemishini neso ukuze kwakhiwe isisekelo solwazi esibanzi sokusekela ukuthuthukiswa nokusetshenziswa kwesikhathi esizayo.Amalensi amaningi okuxhumana e-SiHy atholakala kwezentengiselwano akhiwe ngengxube efanayo yama-polymers e-hydrophilic kanye ne-hydrophobic akha isakhiwo sempahla efanayo17.Ucwaningo oluningana lwenziwe ukuze kuphenywe izakhiwo zabo zemishini kusetshenziswa izindlela zokuhlola zokucindezelwa, ukuqina kanye ne-microindentation18,19,20,21.Kodwa-ke, idizayini yenoveli ye-biomimetic ye-lehfilcon A CL iyenza ibe yinto ehlukile ehlukile lapho izakhiwo zemishini yezakhiwo zebhulashi le-polymer egatsha zihluke kakhulu kulezo ze-SiHy base substrate.Ngakho-ke, kunzima kakhulu ukulinganisa ngokunembile lezi zakhiwo usebenzisa izindlela ezivamile kanye ne-indentation.Indlela ethembisayo isebenzisa indlela yokuhlola i-nanoindentation esetshenziswa ku-atomic force microscopy (AFM), indlela esetshenziselwe ukunquma izakhiwo zemishini yezinto ezithambile ze-viscoelastic ezifana namaseli ebhayoloji nezicubu, kanye nama-polymers athambile angama-22,23,24,25. .,26,27,28,29,30.Ku-AFM nanoindentation, okuyisisekelo kokuhlolwa kwe-nanoindentation kuhlanganiswe nentuthuko yakamuva kubuchwepheshe be-AFM ukuze kuhlinzekwe ukwanda kokuzwela kokulinganisa kanye nokuhlolwa kwezinhlobonhlobo zezinto ezingokwemvelo eziyi-supersoft31,32,33,34,35,36.Ngaphezu kwalokho, ubuchwepheshe bunikeza ezinye izinzuzo ezibalulekile ngokusebenzisa amajiyometri ahlukene.i-indenter kanye ne-probe kanye nethuba lokuhlola emithonjeni ehlukahlukene ye-liquid.
I-AFM nanoindentation ingahlukaniswa ngokwemibandela ibe izingxenye ezintathu eziyinhloko: (1) izinto zokusebenza (izinzwa, izitholi, ama-probes, njll.);(2) amapharamitha wokulinganisa (njengamandla, ukususwa, isivinini, usayizi werempu, njll.);(3) Ukucutshungulwa kwedatha (ukulungiswa okuyisisekelo, isilinganiso sephoyinti lokuthinta, ukufaka idatha, ukumodela, njll.).Inkinga ebalulekile ngale ndlela ukuthi izifundo ezimbalwa ezincwadini ezisebenzisa i-AFM nanoindentation zibika imiphumela yobuningi ehluke kakhulu yesampula efanayo/iseli/impahla37,38,39,40,41.Isibonelo, uLekka et al.Umthelela we-AFM probe geometry kumoduli ka-Young elinganisiwe yamasampula e-hydrogel exubene ngokumshini namaseli ahlukahlukene ahlolisiswa futhi aqhathaniswa.Babika ukuthi amanani e-modulus ancike kakhulu ekukhethweni kwe-cantilever nokuma kwethiphu, ngenani eliphakeme kakhulu lophenyo olumise okwephiramidi kanye nenani eliphansi kakhulu elingu-42 lophenyo oluyindilinga.Ngokufanayo, uSelhuber-Unkel et al.Kubonisiwe ukuthi isivinini se-indenter, usayizi we-indenter nogqinsi lwamasampuli e-polyacrylamide (PAAM) kuyithinta kanjani imoduli Yentsha elinganiswa nge-ACM43 nanoindentation.Enye into enzima ukuntuleka kwezinto zokuhlola ezisezingeni eliphansi kakhulu zemodulus kanye nezinqubo zokuhlola zamahhala.Lokhu kwenza kube nzima kakhulu ukuthola imiphumela enembayo ngokuzethemba.Kodwa-ke, le ndlela iwusizo kakhulu ekulinganiseni okuhlobene nokuhlola okuqhathanisayo phakathi kwezinhlobo zesampula ezifanayo, isibonelo ukusebenzisa i-AFM nanoindentation ukuhlukanisa amangqamuzana avamile kumaseli omdlavuza 44, 45.
Lapho kuhlolwa izinto ezithambile nge-AFM nanoindentation, umthetho ojwayelekile wesithupha ukusebenzisa i-probe ene-low spring constant (k) efana eduze nemodeli yesampula kanye nethiphu ye-hemispherical/round ukuze i-probe yokuqala ingabhobozi izindawo zesampula kuzo. ukuthintana kokuqala ngezinto ezithambile.Kubalulekile futhi ukuthi isignali yokuchezuka ekhiqizwe uphenyo ibe namandla ngokwanele ukuze ibonwe wuhlelo lomtshina we-laser24,34,46,47.Endabeni yamangqamuzana e-ultra-soft heterogeneous, izicubu nama-gel, enye inselele ukunqoba amandla okunamathela phakathi kwe-probe kanye nesampula yesampula ukuze kuqinisekiswe izilinganiso ezikhiqizwayo nezithembekile48,49,50.Kuze kube muva nje, umsebenzi omningi ku-AFM nanoindentation ugxile ocwaningweni lokuziphatha kwemishini kwamaseli ezinto eziphilayo, izicubu, ama-gel, ama-hydrogel, nama-biomolecules esebenzisa ama-spherical probes amakhulu kakhulu, avame ukubizwa ngokuthi ama-colloidal probes (CPs)., 47, 51, 52, 53, 54, 55. Lawa mathiphu ane-radius engu-1 kuya ku-50 µm futhi ngokuvamile enziwa ngengilazi ye-borosilicate, i-polymethyl methacrylate (PMMA), i-polystyrene (PS), i-silicon dioxide (SiO2) ne-diamond- njengekhabhoni (DLC) .Nakuba i-CP-AFM i-nanoindentation ivame ukuba yinketho yokuqala yesampula ethambile, inezinkinga zayo kanye nemikhawulo.Ukusetshenziswa kwamathiphu ayisiyingi amakhulu, anosayizi omncane we-micron kukhulisa indawo yokuxhumana yethiphu ngesampula futhi kuholela ekulahlekeni okukhulu kokulungiswa kwendawo.Ezifanekisweni ezithambile, ezilinganayo, lapho izici zomshini zezakhi zendawo zingase zehluke kakhulu kusukela kusilinganiso endaweni ebanzi, ukuhlehlisa kwe-CP kungafihla noma yikuphi ukungafani kwezakhiwo esikalini sendawo52.Ama-colloidal probe ngokuvamile enziwa ngokunamathisela ama-colloidal spheres angama-micron kuma-cantilever angena-tip kusetshenziswa izinto ezinamathelayo ze-epoxy.Inqubo yokukhiqiza ngokwayo igcwele izinkinga eziningi futhi ingaholela ekuphambeni kwenqubo yokulinganisa uphenyo.Ukwengeza, ubukhulu nobuningi bezinhlayiya ze-colloidal zithinta ngokuqondile imingcele yokulinganisa eyinhloko ye-cantilever, njengemvamisa ye-resonant, ukuqina kwentwasahlobo, nokuzwela kokuphambuka56,57,58.Ngakho-ke, izindlela ezisetshenziswa kakhulu zokuhlola okujwayelekile kwe-AFM, njengokulinganisa izinga lokushisa, zingase zinganikezi ukulinganisa okunembile kwe-CP, futhi kungase kudingeke ezinye izindlela ukuze kwenziwe lokhu kulungiswa57, 59, 60, 61. Ukuhlolwa kokuhlehlisa okujwayelekile kwe-CP kusebenzisa ukuchezuka okukhulu kwe-cantilever ukuze funda izici zamasampuli athambile, okudala enye inkinga lapho kulinganisa ukuziphatha okungaqondile kwe-cantilever ngokuchezuka okukhulu kakhulu62,63,64.Izindlela zesimanje ze-colloidal probe indentation ngokuvamile zicabangela i-geometry ye-cantilever esetshenziselwa ukulinganisa uphenyo, kodwa indiva ithonya lezinhlayiya ze-colloidal, okudala ukungaqiniseki okwengeziwe ngokunemba kwendlela38,61.Ngokufanayo, i-elastic moduli ebalwa ngokufaka imodeli yokuxhumana incike ngokuqondile kujometri ye-indentation probe, futhi ukungafani phakathi kwethiphu kanye nezici zesampula zendawo kungaholela ekungalungisweni27, 65, 66, 67, 68. Omunye umsebenzi wakamuva kaSpencer et al.Izici okufanele zicatshangelwe lapho kuboniswa amabhulashi e-polymer athambile kusetshenziswa indlela ye-CP-AFM ye-nanoindentation ayagqanyiswa.Babike ukuthi ukugcinwa kwe-viscous fluid kumabhulashi e-polymer njengomsebenzi wesivinini kubangela ukwanda kokulayisha kwekhanda futhi ngakho-ke izilinganiso ezihlukene zezakhiwo ezincike ngesivinini30,69,70,71.
Kulolu cwaningo, siphawule i-modulus engaphezulu yezinto ezinwebeka kakhulu ze-ultra-soft i-lehfilcon A CL kusetshenziswa indlela ye-AFM nanoindentation eguquliwe.Njengoba kunikezwe izakhiwo nesakhiwo esisha salokhu kwaziswa, ububanzi bokuzwela bendlela yokuhlehlisa yendabuko alwanele ngokusobala ukuveza imodulus yale nto ethambile kakhulu, ngakho-ke kuyadingeka ukusebenzisa indlela ye-AFM ye-nanoindentation enokuzwela okuphezulu nokuzwela okuphansi.izinga.Ngemva kokubuyekeza amaphutha nezinkinga zamasu akhona e-colloidal AFM probe nanoindentation, sibonisa ukuthi kungani sikhethe uphenyo lwe-AFM oluncanyana, oluklanywe ngokwezifiso ukuze kuqedwe ukuzwela, umsindo ongemuva, ukukhomba iphuzu lokuxhumana, ukulinganisa i-modulus yesivinini sezinto ezithambile ezihlukene ezifana nokugcinwa koketshezi. ukuncika.kanye nokulinganisa okunembile.Ngaphezu kwalokho, sikwazile ukukala ngokunembile umumo nobukhulu bethiphu yokuhlehlisa, okusivumela ukuthi sisebenzise imodeli yokulingana kwe-cone-sphere ukuze sinqume imodulus yokunwebeka ngaphandle kokuhlola indawo yokuxhumana yethiphu ngento.Ukuqagela okubili okungacacile okulinganiswa kulo msebenzi kuyizinto ezibonakalayo ezinwebeka ngokuphelele kanye nemodulus ezimele yokujula kwe-indent.Sisebenzisa le ndlela, siqale sahlola izindinganiso ezithambile kakhulu ngemodulus eyaziwayo ukuze silinganise indlela, bese sisebenzisa le ndlela ukuveza indawo yezinto ezimbili ezihlukene zamalensi.Le ndlela yokuveza izindawo ze-AFM ze-nanoindentation ezinozwela okwandayo kulindeleke ukuthi isebenze ezinhlobonhlobo zezinto ze-biomimetic heterogeneous ultrasoft ezingase zisetshenziswe emishinini yezokwelapha nasezisetshenziswa ze-biomedical.
I-Lehfilcon A contact lens (Alcon, Fort Worth, Texas, USA) kanye nama-silicone hydrogel substrates awo akhethelwe ukuhlolwa kwe-nanoindentation.I-lens yokukhweza eklanywe ngokukhethekile isetshenziswe ekuhloleni.Ukuze ufake i-lens ukuze ihlolwe, yayibekwe ngokucophelela endaweni yokumisa emise okwedome, iqinisekisa ukuthi awekho amabhamuza omoya angena ngaphakathi, bese ilungiswa ngemiphetho.Imbobo endaweni engaphezulu kwesibambi silensi inikeza ukufinyelela enkabeni yokubona yelensi yokuhlolwa kwe-nanoindentation kuyilapho ubambe uketshezi endaweni.Lokhu kugcina amalensi egcwele amanzi.I-500 μl yesisombululo sokupakisha se-lens yasetshenziswa njengesixazululo sokuhlola.Ukuze kuqinisekiswe imiphumela yobuningi, ama-hydrogel atholakala ngokwentengiso angacushiwe e-polyacrylamide (PAAM) alungiselwe ukwakheka kwe-polyacrylamide-co-methylene-bisacrylamide (100 mm Petrisoft Petri izitsha, Matrigen, Irvine, CA, USA), imodulus enwebekayo eyaziwayo engu-1. kPa.Sebenzisa amaconsi angu-4-5 (cishe ama-125 µl) e-phosphate buffered saline (PBS evela ku-Corning Life Sciences, Tewkesbury, MA, USA) kanye neconsi elingu-1 lesisombululo selensi yokuxhumana ye-OPTI-FREE Puremoist (Alcon, Vaud, TX, USA).) kusixhumi esibonakalayo se-AFM hydrogel-probe.
Amasampula ama-substrates e-Lehfilcon A CL kanye ne-SiHy abonwa ngeso lengqondo kusetshenziswa uhlelo lwe-FEI Quanta 250 Field Emission Scanning Electron Microscope (FEG SEM) olufakwe umtshina we-Scanning Transmission Electron Microscope (STEM).Ukuze kulungiswe amasampula, amalensi aqale agezwe ngamanzi futhi asikwe abe amaweji amise okwephayi.Ukuze kuzuzwe umehluko ohlukile phakathi kwezingxenye ze-hydrophilic ne-hydrophobic zamasampuli, isisombululo esizinzile se-0.10% se-RuO4 sisetshenziswe njengodayi, lapho amasampula acwiliswa khona imizuzu engu-30.I-lehfilcon A CL RuO4 staining ibalulekile hhayi nje ukufeza ukuhluka okuthuthukisiwe okuthuthukisiwe, kodwa futhi kusiza ukulondoloza ukwakheka kwamabhulashi e-polymer egatsha ngendlela yawo yasekuqaleni, abese ebonakala ezithombeni ze-STEM.Zabe sezigezwa futhi zaphelelwa amanzi ochungechungeni lwezingxube ze-ethanol/zamanzi ngokukhula kwe-ethanol.Amasampuli abe esephonswa nge-EMBed 812/Araldite epoxy, elapheka ngobusuku obungu-70°C.Amabhulokhi amasampula atholwe nge-resin polymerization asikwa nge-ultramicrotome, futhi izigaba ezincane eziwumphumela zabonwa ngomtshina we-STEM kumodi ye-vacuum ephansi ku-voltage esheshayo engu-30 kV.Kwasetshenziswa uhlelo olufanayo lwe-SEM ukuze kuchazwe imininingwane yophenyo lwe-PFQNM-LC-A-CAL AFM (Bruker Nano, Santa Barbara, CA, USA).Izithombe ze-SEM zophenyo lwe-AFM zitholwe ngemodi ye-vacuum ephezulu evamile enevolthi esheshayo engu-30 kV.Thola izithombe ngama-engeli ahlukene kanye nokukhuliswa ukuze urekhode yonke imininingwane yomumo nosayizi wethiphu ye-AFM probe.Zonke izilinganiso zethiphu yentshisekelo ezithombeni zikalwe ngedijithali.
I-Dimension FastScan Bio Icon ye-atomic force microscope (Bruker Nano, Santa Barbara, CA, USA) enemodi ye-“PeakForce QNM in Fluid” isetshenziswe ukuze kubonakale ngeso lengqondo kanye ne-nanoindentate lehfilcon A CL, i-SiHy substrate, namasampuli e-hydrogel e-PAAm.Ngokuhlolwa kwesithombe, i-PEAKFORCE-HIRS-FA probe (Bruker) enerediyasi yethiphu engu-1 nm isetshenziswe ukuthwebula izithombe ezinokulungiswa okuphezulu kwesampula ngesilinganiso sokuskena esingu-0.50 Hz.Zonke izithombe zithathwe ngesisombululo esinamanzi.
Ukuhlolwa kwe-AFM nanoindentation kwenziwe kusetshenziswa i-PFQNM-LC-A-CAL probe (Bruker).I-AFM probe inethiphu ye-silicon ku-nitride cantilever engu-345 nm ubukhulu, 54 µm ubude no-4.5 µm ububanzi nemvamisa ezwakalayo engu-45 kHz.Idizayinelwe ngokuqondile ukukhombisa nokwenza izilinganiso ze-nanomechanical zobuningi kumasampula ebhayoloji athambile.Izinzwa zilinganiswa ngazodwana efekthri ngezilungiselelo zasentwasahlobo ezilinganiswe ngaphambilini.Izimo zentwasahlobo zama-probe ezisetshenziswe kulolu cwaningo zazisebangeni lika-0.05–0.1 N/m.Ukuze unqume ngokunembile umumo nosayizi wethiphu, uphenyo luphawulwe ngokuningiliziwe kusetshenziswa i-SEM.Emkhiwaneni.Umfanekiso 1a ubonisa ukulungiswa okuphezulu, ukuskena okuphansi kwe-electron micrograph ye-PFQNM-LC-A-CAL probe, enikeza umbono ophelele wedizayini yophenyo.Emkhiwaneni.I-1b ikhombisa ukubuka okukhulisiwe kwengaphezulu kwethiphu ye-probe, ihlinzeka ngolwazi mayelana nokuma nosayizi wethiphu.Ekugcineni, inaliti iyi-hemisphere engaba ngu-140 nm ububanzi (Fig. 1c).Ngezansi kwalokhu, ithiphu ithinta umumo oyindilinga, ifinyelela ubude obulinganisiwe obucishe bube ngu-500 nm.Ngaphandle kwesifunda se-tapering, ichopho liyisilinda futhi liphela ngengqikithi yobude bethiphu engu-1.18 µm.Lena ingxenye eyinhloko yokusebenza yethiphu ye-probe.Ngaphezu kwalokho, i-probe enkulu eyindilinga ye-polystyrene (PS) (Novascan Technologies, Inc., Boone, Iowa, USA) enobubanzi bethiphu engu-45 µm kanye ne-spring constant engu-2 N/m nayo yasetshenziswa ukuze ihlolwe njenge-colloidal probe.nge-PFQNM-LC-A-CAL 140 nm probe ukuze iqhathanise.
Kubikwe ukuthi uketshezi lungavaleleka phakathi kwe-AFM probe kanye nesakhiwo sebhulashi le-polymer ngesikhathi se-nanoindentation, okuzosebenzisa amandla akhuphukayo kuphenyo lwe-AFM ngaphambi kokuthi luthinte indawo ephezulu69.Lo mphumela we-viscous extrusion ngenxa yokugcinwa koketshezi ungashintsha indawo okubonakala kuxhumene kuyo, ngaleyo ndlela kuthinte izilinganiso zemodulus yangaphezulu.Ukuze kufundwe umthelela we-probe geometry kanye nesivinini sokuhlehlisa ekugcinweni koketshezi, amajika amandla okwehla ahlelelwa amasampula e-lehfilcon A CL kusetshenziswa i-140 nm diameter probe ngezinga eliqhubekayo lokugudluka elingu-1 µm/s no-2 µm/s.Ububanzi be-probe 45 µm, ukusetha amandla angaguquki okungu-6 nN kufinyelelwe ku-1 µm/s.Ukuhlolwa okune-probe engu-140 nm ububanzi kwenziwa ngesivinini sokuhlehlisa esingu-1 µm/s kanye nesethi yamandla angu-300 pN, ekhethelwe ukudala ingcindezi yokuxhumana phakathi kwebanga le-physiological (1–8 kPa) lejwabu leso eliphezulu.ukucindezela 72. Amasampula enziwe athambile enziwe nge-PAA hydrogel anengcindezi ye-1 kPa ahlolwe amandla oku-indentation angu-50 pN ngesivinini esingu-1 μm/s kusetshenziswa i-probe enobubanzi obuyi-140 nm.
Njengoba ubude bengxenye ye-conical yethiphu ye-PFQNM-LC-A-CAL probe cishe i-500 nm, kunoma yikuphi ukujula kwe-indentation <500 nm kungacatshangwa ngokuphephile ukuthi i-geometry ye-probe ngesikhathi sokuhlehlisa izohlala iyiqiniso isimo sekhoni.Ngaphezu kwalokho, kucatshangwa ukuthi ingaphezulu lezinto ezivivinywayo zizobonisa impendulo eguqukayo eguqukayo, futhi ezoqinisekiswa ezigabeni ezilandelayo.Ngakho-ke, kuye ngomumo nosayizi wethiphu, sikhethe imodeli yokulingana kwe-cone-sphere eyakhiwe nguBriscoe, Sebastian no-Adams, etholakala kusofthiwe yomthengisi, ukucubungula ukuhlolwa kwethu kwe-AFM nanoindentation (NanoScope).Isofthiwe yokuhlaziya idatha ngokuhlukana, i-Bruker) 73. Imodeli ichaza ubudlelwano bokugudluza ngamandla F(δ) kukhoni enesici esiyisiyingi se-apex.Emkhiwaneni.Umfanekiso 2 ubonisa i-geometry yokuxhumana ngesikhathi sokusebenzisana kwekhoni eqinile enesihloko esiyindilinga, lapho u-R eyirediyasi yesihloko esiyindilinga, a iyirediyasi yokuxhumana, b iyirediyasi yokuxhumana ekugcineni kwethiphu eyindilinga, δ irediyo yokuxhumana.ukujula kokuhlehlisa, θ uhhafu we-engeli yekhoni.Isithombe se-SEM sale probe sibonisa ngokusobala ukuthi ithiphu eliyindilinga elingu-140 nm lihlangana ngokuzenzakalelayo libe ikhoni, ngakho lapha b uchazwa ngo-R kuphela, okungukuthi b = R cos θ.Isofthiwe ehlinzekwe ngumthengisi ihlinzeka ngobudlelwano be-cone-sphere ukubala amanani we-Young's modulus (E) kusuka kudatha yokuhlukanisa ngamandla ngokuthatha a > b.Ubudlelwano:
lapho u-F engamandla e-indent, u-E eyimoduli ka-Young, ν isilinganiso sika-Poisson.Irediyasi yokuxhumana a ingalinganiswa kusetshenziswa:
Uhlelo lwejiyomethri yokuxhumana yekhoni eqinile enethiphu eyindilinga ecindezelwe olwazini lwelensi yokuxhumana ye-Lefilcon enongqimba olungaphezulu lwamabhulashi e-polymer enamagatsha.
Uma u-≤ b, ukuhlobana kunciphisa kusibalo se-indenter eyindilinga evamile;
Sikholelwa ukuthi ukusebenzelana kwe-probe yokuhlehlisa ngesakhiwo esinamagatsha ebhulashi lepolymer ye-PMPC kuzobangela irediyasi yokuxhumana ukuthi ibe nkulu kune-spherical contact radius b.Ngakho-ke, kuzo zonke izilinganiso zobuningi bemoduli enwebekayo eyenziwe kulolu cwaningo, sisebenzise ukuncika okutholwe esimweni a > b.
Izinto ze-ultrasoft biomimetic ezifundwe kulolu cwaningo zenziwe ngesithombe esibanzi kusetshenziswa i-scanning transmission electron microscopy (STEM) yesampula yesiphambano sesigaba kanye ne-atomic force microscopy (AFM) yangaphezulu.Lesi sici sobuso esinemininingwane senziwe njengesandiso somsebenzi wethu oshicilelwe ngaphambilini, lapho sinqume khona ukuthi isakhiwo sebhulashi se-polymeric esinegatsha eliguquguqukayo se-lehfilcon A CL sendawo ye-PMPC-modified lehfilcon A CL surface sibonise izici zomshini ezifanayo kuzicubu ze-cornea zomdabu 14.Ngenxa yalesi sizathu, sibhekisela ezindaweni zokuxhumana ezifana ne-biomimetic material14.Emkhiwaneni.I-3a,b ibonisa izingxenye eziphambanayo zezakhiwo zebhulashi le-polymer ye-PMPC enamagatsha endaweni engaphansi ye-lehfilcon A CL kanye ne-SiHy substrate engalungiswanga, ngokulandelana.Ukuphakama kwawo womabili amasampula kwahlaziywa ngokuqhubekayo kusetshenziswa izithombe ze-AFM ezinesinqumo esiphezulu, okwaqinisekisa ngokwengeziwe imiphumela yokuhlaziywa kwe-STEM (Fig. 3c, d).Uma zihlanganiswa, lezi zithombe zinikeza ubude obulinganiselwe besakhiwo sebhulashi le-polymer egatsha le-PMPC ku-300–400 nm, okubalulekile ekuhumusheni izilinganiso ze-AFM ze-nanoindentation.Okunye ukuqaphela okubalulekile okutholakala ezithombeni ukuthi ukwakheka kwendawo yonke ye-CL biomimetic impahla ye-morphologically ihluke kulokho kwe-SiHy substrate material.Lo mehluko ku-morphology yawo engaphezulu ungabonakala phakathi nokusebenzisana kwawo okuwumshini nophenyo oluhlehlisayo lwe-AFM futhi kamuva kumanani emodulus akaliwe.
Izithombe ze-STEM ezihlukene (a) ze-lehfilcon A CL kanye (b) ne-SiHy substrate.Ibha yesikali, 500 nm.Izithombe ze-AFM zengaphezulu le-lehfilcon A CL substrate (c) kanye nesisekelo se-SiHy substrate (d) (3 µm × 3 µm).
Ama-polymers e-Bioinspired kanye nezakhiwo zebhulashi le-polymer athambile ngokwemvelo futhi acutshungulwe kabanzi futhi asetshenziswa ezinhlelweni ezihlukahlukene ze-biomedical74,75,76,77.Ngakho-ke, kubalulekile ukusebenzisa indlela ye-AFM ye-nanoindentation, engakwazi ukukala ngokunembile nangokuthembekile izakhiwo zabo zemishini.Kodwa ngesikhathi esifanayo, izici eziyingqayizivele zalezi zinto ezithambile kakhulu, njenge-modulus ephansi kakhulu enwebekayo, okuqukethwe okuphezulu kwe-liquid kanye nokunwebeka okuphezulu, kuvame ukwenza kube nzima ukukhetha izinto ezifanele, ukwakheka nokuma kwe-indenting probe.usayizi.Lokhu kubalulekile ukuze i-indenter ingabhobozi indawo ethambile yesampula, okungaholela emaphutheni ekunqumeni iphoyinti lokuxhumana nendawo kanye nendawo yokuxhumana.
Kulokhu, ukuqonda okuphelele kwe-morphology yezinto ze-ultra-soft biomimetic (lehfilcon A CL) kubalulekile.Ulwazi mayelana nobukhulu nokwakheka kwamabhulashi e-polymer e-branched atholwe kusetshenziswa indlela yokuthwebula ihlinzeka ngesisekelo sokubonakaliswa komshini kwendawo kusetshenziswa amasu e-AFM nanoindentation.Esikhundleni se-micron-size spherical colloidal probes, sikhethe i-PFQNM-LC-A-CAL silicon nitride probe (Bruker) enobubanzi bethiphu engu-140 nm, eklanyelwe ngokukhethekile ukwakheka kwemephu kwenani lezakhiwo zemishini yamasampula ebhayoloji 78, 79, 80. , 81, 82, 83, 84 Isizathu sokusebenzisa ama-probe abukhali ngokuqhathaniswa nama-colloidal probes avamile angachazwa izici zesakhiwo sezinto ezibonakalayo.Ukuqhathanisa usayizi wethiphu ye-probe (~140 nm) namabhulashi e-polymer enamagatsha ebusweni be-CL lehfilcon A, eboniswe ku-Fig. 3a, kungaphethwa ngokuthi ithiphu likhulu ngokwanele ukuthi lihlangane ngqo nalezi zakhiwo zebhulashi, okuyinto kunciphisa amathuba okuthi ithiphu ibhoboze kuzo.Ukukhombisa leli phuzu, ku-Fig. 4 isithombe se-STEM se-lehfilcon A CL kanye nethiphu yokuhlehlisa ye-AFM probe (edonswa esikalini).
Isikimu esibonisa isithombe se-STEM se-lehfilcon A CL kanye ne-ACM indentation probe (edwetshwe esikalini).
Ukwengeza, usayizi wethiphu we-140 nm mncane ngokwanele ukugwema ubungozi banoma yimiphi imiphumela enamathelayo ye-extrusion ebibikwe ngaphambilini ngamabhulashi e-polymer akhiqizwa indlela ye-CP-AFM nanoindentation69,71.Sicabanga ukuthi ngenxa yesimo esikhethekile se-cone-spherical kanye nobukhulu obuncane baleli thiphu ye-AFM (Fig. 1), imvelo yejika lamandla ekhiqizwe i-lehfilcon A CL nanoindentation ngeke incike kwisivinini sokuhlehlisa noma isivinini sokulayisha/ukulayisha. .Ngakho-ke, ayithinteki ngemiphumela ye-poroelastic.Ukuhlola le nkoleloze, amasampula e-lehfilcon A CL aye ahlehliswa ngamandla amakhulu angaguquki kusetshenziswa i-PFQNM-LC-A-CAL probe, kodwa ngamavelovithi amabili ahlukene, kanye namajika anamandla okuhoxisa asetshenzisiwe ukuze ahlele amandla (nN) ngokuhlukana (µm) kukhonjiswe kuMfanekiso 5a.Kuyacaca ukuthi amandla amajika ngesikhathi sokulayisha nokuthulula agqagqana ngokuphelele, futhi abukho ubufakazi obucacile bokuthi ukugunda kwamandla ekujuleni kwe-zero kukhuphuka ngesivinini sokuhlehlisa emfanekisweni, okuphakamisa ukuthi izakhi zebhulashi ngazinye ziphawulwe ngaphandle komphumela we-poroelastic.Ngokuphambene, imiphumela yokugcinwa koketshezi (i-viscous extrusion kanye nemiphumela ye-poroelasticity) ibonakala kuphenyo lwe-AFM engu-45 µm ngesivinini esifanayo sokuhlehlisa futhi igqanyiswa yi-hysteresis phakathi kokwelula nokuhlehlisa ijika, njengoba kuboniswe kumfanekiso 5b.Le miphumela isekela i-hypothesis futhi iphakamisa ukuthi ama-probes we-diameter angu-140 nm ayinketho enhle yokubonisa izindawo ezithambile ezinjalo.
i-lehfilcon A CL indentation force curves isebenzisa i-ACM;(a) kusetshenziswa i-probe enobubanzi obungu-140 nm ngamanani amabili okulayisha, okubonisa ukungabikho komthelela we-poroelastic ngesikhathi sokuhlehlisa phezulu;(b) usebenzisa ama-probe anobubanzi obungu-45 µm no-140 nm.s ikhombisa imiphumela ye-viscous extrusion kanye ne-poroelasticity yama-probe amakhulu uma kuqhathaniswa nama-probe amancane.
Ukuze kubonakale izindawo ezingaphezulu ze-ultrasoft, izindlela ze-AFM nanoindentation kumele zibe nophenyo olungcono kakhulu lokufunda izici zento efundwayo.Ngaphandle komumo wethiphu nosayizi, ukuzwela kwesistimu yomtshina we-AFM, ukuzwela ukuphambuka kwethiphu endaweni yokuhlola, nokuqina kwe-cantilever kudlala indima ebalulekile ekunqumeni ukunemba nokuthembeka kwe-nanoindentation.izilinganiso.Kusistimu yethu ye-AFM, umkhawulo wokutholwa Wendawo Ebucayi (PSD) ucishe ube ngu-0.5 mV futhi usekelwe esilinganisweni sentwasahlobo esilinganiswe ngaphambilini kanye nokuzwela koketshezi olubaliwe olubaliwe lwe-PFQNM-LC-A-CAL probe, ehambisana ukuzwela komthwalo wethiyori.ingaphansi kuka-0.1 pN.Ngakho-ke, le ndlela ivumela ukukalwa kwamandla amancane wokuhlehlisa ≤ 0.1 pN ngaphandle kwanoma iyiphi ingxenye yomsindo we-peripheral.Kodwa-ke, cishe akunakwenzeka ngohlelo lwe-AFM ukunciphisa umsindo we-peripheral uze ufike kuleli zinga ngenxa yezinto ezifana nokudlidliza komshini kanye nokuguquguquka koketshezi.Lezi zici zikhawulela ukuzwela okuphelele kwendlela ye-AFM ye-nanoindentation futhi iphinde ibangele isignali yomsindo yangemuva ecishe ibe ngu-≤ 10 pN.Ukuze kufakwe umlingiswa ongaphezulu, amasampula e-lehfilcon A CL kanye ne-SiHy substrate aye ahlehliswa ngaphansi kwezimo ezinama-hydrated ngokugcwele kusetshenziswa i-probe engu-140 nm ye-SEM characterization, futhi amajika wamandla abe umphumela wabekwa phezulu phakathi kwamandla (pN) nokucindezela.Isakhiwo sokuhlukanisa (µm) sikhonjisiwe kuMfanekiso 6a.Uma kuqhathaniswa ne-SiHy base substrate, ijika lamandla e-lehfilcon A CL libonisa ngokucacile isigaba senguquko esiqala endaweni yokuxhumana nebhulashi le-polymer enemfologo futhi siphethe ngoshintsho olubukhali ekuphawuleni kophawu lokuthintana kwethiphu ngento engaphansi.Le ngxenye yenguquko yejiko lamandla igqamisa ukuziphatha okunwebeka ngempela kwebhulashi le-polymer enegatsha elingaphezulu, njengoba kufakazelwa ijika lokuminyanisa elilandela eduze ijika le-tension kanye nokugqama kwezakhiwo zemishini phakathi kwesakhiwo sebhulashi nezinto ezinkulu ze-SiHy.Lapho uqhathanisa i-lefilcon.Ukuhlukaniswa kobude obumaphakathi bebhulashi le-polymer enegatsha esithombeni se-STEM se-PCS (Umfanekiso 3a) kanye nejika lamandla ayo eduze kwe-abscissa ku-Fig. 3a.I-6a ikhombisa ukuthi indlela iyakwazi ukubona ithiphu kanye ne-polymer enegatsha ifinyelela phezulu kakhulu.Ukuxhumana phakathi kwezakhiwo zebhulashi.Ngaphezu kwalokho, ukugqagqana okuseduze kwamajika wamandla kukhombisa ukuthi awukho umthelela wokugcina uketshezi.Kulokhu, akukho nhlobo ukunamathela phakathi kwenaliti kanye nobuso besampula.Izingxenye eziphezulu kakhulu zamajika amandla amasampula amabili ayagqagqana, okubonisa ukufana kwezakhiwo zemishini zezinto ezingaphansi.
(a) Amajika e-AFM nanoindentation force ama-substrates e-lehfilcon A CL kanye nama-substrates e-SiHy, (b) phoqa amajika abonisa isilinganiso sephoyinti lokuxhumana kusetshenziswa indlela yomkhawulo womsindo wangemuva.
Ukuze ufunde imininingwane emincane yejika lamandla, ijika le-tension yesampula ye-lehfilcon A CL iphinda ifakwe ku-Fig. 6b ngamandla amakhulu angu-50 pN ku-axis engu-y.Le grafu inikeza ulwazi olubalulekile mayelana nomsindo wangemuva wangempela.Umsindo usebangeni elingu-±10 pN, elisetshenziselwa ukunquma ngokunembile indawo yokuxhumana nokubala ukujula kokuhlehlisa.Njengoba kubikiwe ezincwadini, ukukhonjwa kwezindawo zokuxhumana kubalulekile ukuze kuhlolwe ngokunembile izakhiwo zezinto ezibonakalayo njenge-modulus85.Indlela ehilela ukucutshungulwa okuzenzakalelayo kwedatha yejika lamandla ibonise ukulingana okuthuthukisiwe phakathi kokufaka idatha kanye nezilinganiso zobuningi zezinto ezithambile86.Kulo msebenzi, ukukhetha kwethu amaphuzu okuxhumana kulula futhi kunenjongo, kodwa kunemikhawulo yawo.Indlela yethu elandelanayo yokunquma indawo yokuxhumana ingase ibangele amanani emodulus aqikelelwe kakhulu ekujuleni okuncane kokuhlehlisa (< 100 nm).Ukusetshenziswa kokutholwa kwendawo yokuthinta okusekelwe ku-algorithm nokucubungula idatha okuzenzakalelayo kungase kube ukuqhubeka kwalo msebenzi esikhathini esizayo ukuze sithuthukise indlela yethu.Ngakho, ngomsindo wangemuva ongaphakathi ohlelweni lwe-±10 pN, sichaza indawo yokuxhumana njengephoyinti ledatha lokuqala ku-x-axis ku-Figure 6b enenani elingu-≥10 pN.Bese, ngokuhambisana nomkhawulo womsindo ongu-10 pN, umugqa oqondile ezingeni lika-~0.27 µm uphawula iphoyinti lokuxhumana nendawo, ngemva kwalokho ijika elinwebekayo liqhubeka kuze kube i-substrate ihlangana nokujula kokuhlehlisa okungu-~270 nm.Kuyathakazelisa ukuthi ngokususelwe kusayizi wezici zebhulashi le-polymer enegatsha (300–400 nm) zikalwa kusetshenziswa indlela yokuthwebula, ukujula kokuhlehlisa kwe-CL lehfilcon A isampula ebonwe kusetshenziswa indlela yomkhawulo womsindo wangemuva cishe ku-270 nm, eseduze kakhulu usayizi wokulinganisa nge-STEM.Le miphumela iqhubeka iqinisekisa ukuhambisana nokusebenziseka kwesimo kanye nosayizi wethiphu ye-AFM yokuphenya ukuze kufakwe i-indent yalesi sakhiwo sebhulashi le-polymer elithambile futhi elinwebeka kakhulu.Le datha iphinde inikeze ubufakazi obuqinile bokusekela indlela yethu yokusebenzisa umsindo ongemuva njengomkhawulo wokukhomba izindawo zokuxhumana.Ngakho-ke, noma yimiphi imiphumela yobuningi etholwe kumodeli yezibalo kanye nokufakwa kwejika lejika kufanele inembe ngokuqhathaniswa.
Izilinganiso zobuningi bezindlela ze-AFM ze-nanoindentation zincike ngokuphelele kumamodeli ezibalo asetshenziselwa ukukhethwa kwedatha nokuhlaziya okulandelayo.Ngakho-ke, kubalulekile ukucabangela zonke izici ezihlobene nokukhethwa kwe-indenter, izakhiwo zezinto ezibonakalayo kanye nemishini yokusebenzisana kwazo ngaphambi kokukhetha imodeli ethile.Kulokhu, i-tip geometry iphawulwe ngokucophelela kusetshenziswa ama-micrographs e-SEM (Fig. 1), futhi ngokusekelwe emiphumeleni, i-140 nm ububanzi be-AFM nanoindenting probe ene-cone eqinile kanye ne-spherical tip geometry iyisinqumo esihle sokuhlukanisa amasampula e-lehfilcon A CL79. .Esinye isici esibalulekile esidinga ukuhlolwa ngokucophelela ukunwebeka kwe-polymer material ehlolwayo.Nakuba idatha yokuqala ye-nanoindentation (Amakhiwane 5a no-6a) iveza ngokucacile izici zokugqagqana kwe-tension kanye namajika okucindezela, okungukuthi, ukubuyiswa okuphelele kokunwebeka kwempahla, kubaluleke kakhulu ukuqinisekisa ukunwebeka okumsulwa koxhumana nabo. .Kuze kube manje, ukuhlehlisa okubili okulandelanayo kwenziwa endaweni efanayo endaweni yesampula ye-lehfilcon A CL ngesilinganiso sokuhlehlisa esingu-1 µm/s ngaphansi kwezimo zokugeleza kwamanzi ngokugcwele.Idatha yejika yamandla ewumphumela iboniswa ku-fig.7 futhi, njengoba kulindelekile, ukunwetshwa nokucindezelwa kwamajika amaphrinti amabili acishe afane, agqamisa ukunwebeka okuphezulu kwesakhiwo sebhulashi le-polymer enegatsha.
Amajika wamandla wokuhlehlisa amabili endaweni efanayo endaweni ye-lehfilcon A CL abonisa ukunwebeka okufanelekile kwendawo yelensi.
Ngokusekelwe olwazini olutholwe ku-SEM nezithombe ze-STEM zethiphu ye-probe kanye nendawo ye-lehfilcon A CL, ngokulandelanayo, imodeli ye-cone-sphere iwumfanekiso wezibalo onengqondo wokusebenzisana phakathi kwethiphu ye-AFM probe kanye nokokusebenza kwe-polymer ethambile ehlolwayo.Ukwengeza, kule modeli ye-cone-sphere, ukuqagela okuyisisekelo mayelana nezakhiwo ezinwebekayo zezinto eziphrintiwe kuyiqiniso kule nto entsha ye-biomimetic futhi isetshenziselwa ukulinganisa i-elastic modulus.
Ngemva kokuhlolwa okuphelele kwendlela ye-AFM ye-nanoindentation kanye nezingxenye zayo, okuhlanganisa izakhiwo ze-indentation probe (umumo, usayizi, nokuqina kwentwasahlobo), ukuzwela (umsindo ongemuva nokulinganisa kwephoyinti lokuxhumana), kanye namamodeli afaka idatha (izilinganiso zemodulus yobuningi), indlela esetshenzisiwe.bonisa amasampula athambile kakhulu atholakala ngokwentengiso ukuze kuqinisekiswe imiphumela yobuningi.I-hydrogel yezohwebo ye-polyacrylamide (PAAM) enemodulus enwebekayo engu-1 kPa ihlolwe ngaphansi kwezimo ezinama-hydrated kusetshenziswa i-probe engu-140 nm.Imininingwane yokuhlolwa kwamamojula nokubala inikezwe Olwazini Olwengeziwe.Imiphumela yabonisa ukuthi isilinganiso semodulus esikaliwe sasingu-0.92 kPa, kanti ukuchezuka kwe-%RSD namaphesenti (%) kumodulus eyaziwayo kwakungaphansi kuka-10%.Le miphumela iqinisekisa ukunemba nokukhiqizwa kabusha kwendlela ye-AFM ye-nanoindentation esetshenziswe kulo msebenzi ukukala i-moduli yezinto ze-ultrasoft.Izingxenye ezingaphezulu zamasampula e-lehfilcon A CL kanye nesisekelo sesisekelo se-SiHy kwaphinde kwaphawulwa kusetshenziswa indlela efanayo ye-AFM ye-nanoindentation ukuze kufundwe imodulus ebonakalayo yokuxhumana kwendawo ye-ultrasoft njengomsebenzi wokujula kokuhlehlisa.Amajika okuhlukanisa amandla okwehlisa akhiqizelwe izifanekiso ezintathu zohlobo ngalunye (n = 3; ukuhlehlisa okukodwa ngesampula ngayinye) ngamandla angu-300 pN, isivinini esingu-1 µm/s, kanye nokugeleza kwamanzi okugcwele.Ijika lokwabelana lamandla okwehlisa lilinganiswe kusetshenziswa imodeli ye-cone-sphere.Ukuze uthole i-modulus encike ekujuleni kokuhlehlisa, ingxenye ebanzi engu-40 nm yejika lamandla yamiswa ekunyukeni ngakunye okungu-20 nm kusukela endaweni yokuxhumana, kanye namanani alinganiselwe emoduli esinyathelweni ngasinye sejika lamandla.Spin Cy et al.Indlela efanayo iye yasetshenziswa ukuveza i-modulus gradient ye-poly(lauryl methacrylate) (P12MA) yamabhulashi e-polymer kusetshenziswa i-colloidal AFM probe nanoindentation, futhi ahambisana nedatha esebenzisa imodeli yokuxhumana yakwa-Hertz.Le ndlela ihlinzeka ngesakhiwo semodulus ebonakalayo yokuxhumana (kPa) iqhathaniswa nokujula kwe-indent (nm), njengoba kukhonjisiwe kuMfanekiso 8, obonisa imodulus/ukujula kwegradient.Imoduli enwebekayo ebaliwe yesampula ye-CL lehfilcon A ikububanzi obungu-2–3 kPa ngaphakathi kuka-100 nm ongaphezulu wesampula, lapho iqala khona ukwanda ngokujula.Ngakolunye uhlangothi, lapho kuhlolwa i-substrate yesisekelo se-SiHy ngaphandle kwefilimu efana nebhulashi ebusweni, ukujula okukhulu kokuhlehlisa okutholwe ngamandla angu-300 pN kungaphansi kuka-50 nm, futhi inani lemodulus elitholwe kudatha licishe libe ngu-400 kPa. , eqhathaniswa namagugu e-Young's modulus yezinto eziningi.
Imodulus yokuxhumana ebonakalayo (kPa) vs. ukujula kwe-indent (nm) ye-lehfilcon A CL ne-SiHy substrates esebenzisa indlela ye-AFM nanoindentation ene-cone-sphere geometry ukuze kukale imodulus.
Indawo ephezulu yenoveli ye-biomimetic branched polymer brush structure ibonisa imodulus ephansi kakhulu yokunwebeka (2–3 kPa).Lokhu kuzofanelana nokuphela kwamahhala okulengayo kwebhulashi le-polymer elinemfoloko njengoba kukhonjisiwe esithombeni se-STEM.Nakuba kunobunye ubufakazi be-modulus gradient emaphethelweni angaphandle e-CL, i-modulus substrate ephezulu eyinhloko inethonya elikhulu.Kodwa-ke, i-100 nm ephezulu yobuso ingaphakathi kuka-20% wobude obuphelele bebhulashi le-polymer enegatsha, ngakho-ke kunengqondo ukucabanga ukuthi amanani alinganisiwe we-modulus kulolu hlu lokujula anembile futhi awanamandla kakhulu. kuncike emphumeleni wento engezansi.
Ngenxa yomklamo oyingqayizivele we-biomimetic we-lehfilcon A contact lens, ehlanganisa izakhiwo zebhrashi ze-polymer ze-PMPC ezinamagatsha ezixhunywe phezu kwama-substrates e-SiHy, kunzima kakhulu ukuveza ngokuthembekile izici zemishini yezakhiwo zawo ezingaphezulu usebenzisa izindlela zokulinganisa zendabuko.Lapha sethula indlela ye-AFM ye-nanoindentation ethuthukisiwe yokufaka ngokunembile izinto ezithambile ezithambile njenge-lefilcon A enamanzi amaningi nokunwebeka okuphezulu kakhulu.Le ndlela isekelwe ekusetshenzisweni kophenyo lwe-AFM usayizi wayo wethiphu nejiyomethri kukhethwe ngokucophelela ukuze kufane nobukhulu besakhiwo sezinto ezithambile ezizophrintwa.Le nhlanganisela yobukhulu phakathi kwe-probe kanye nesakhiwo inikeza ukuzwela okukhulayo, okusivumela ukuthi silinganise imodulus ephansi kanye nezakhiwo ezinwebekayo zemvelo zama-elementi ebhulashi le-polymer enamagatsha, kungakhathaliseki imiphumela ye-poroelastic.Imiphumela yabonisa ukuthi isici esiyingqayizivele samabhulashi e-polymer ye-PMPC enegatsha lendawo yelensi anemodulus enwebekayo ephansi kakhulu (efika ku-2 kPa) kanye nokunwebeka okuphezulu kakhulu (cishe u-100%) lapho ihlolwa endaweni enamanzi.Imiphumela ye-AFM nanoindentation iphinde yasivumela ukuba sibonise imodulus/igradient ejulile yokuxhumana (30 kPa/200 nm) yendawo yelensi ye-biomimetic.Le gradient ingase ibe ngenxa yomehluko we-modulus phakathi kwamabhulashi e-polymer enamagatsha kanye ne-SiHy substrate, noma isakhiwo esinamagatsha/ukuminyana kwamabhulashi e-polymer, noma inhlanganisela yakho.Kodwa-ke, ezinye izifundo ezijulile ziyadingeka ukuze uqonde ngokugcwele ubudlelwano phakathi kwesakhiwo nezakhiwo, ikakhulukazi umthelela we-brush branching ezimpahleni zemishini.Izilinganiso ezifanayo zingasiza ukuveza izici zemishini zobuso bezinye izinto ezithambile kakhulu namadivayisi ezokwelapha.
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