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Ngokuthuthukiswa kwezinto ezintsha ezithambile kakhulu zamadivayisi ezokwelapha kanye nezinhlelo zokusebenza zezokwelapha, ukucaciswa okuphelele kwezakhiwo zazo zomzimba nezemishini kubalulekile futhi kuyinselele. Indlela ye-nanoindentation ye-atomic force microscopy (AFM) eguquliwe yasetshenziswa ukuchaza i-modulus ephansi kakhulu ebusweni be-lehfilcon entsha. Ilensi yokuxhumana ye-biomimetic silicone hydrogel embozwe ungqimba lwezakhiwo zebhulashi le-polymer elinegatsha. Le ndlela ivumela ukunqunywa okunembile kwamaphuzu okuxhumana ngaphandle kwemiphumela ye-extrusion ene-viscous lapho kusondela kuma-polymer anegatsha. Ngaphezu kwalokho, kwenza kube nokwenzeka ukunquma izici zemishini zezinto zebhulashi ngazinye ngaphandle komphumela we-poroelasticity. Lokhu kufezwa ngokukhetha i-probe ye-AFM enomklamo (usayizi wethiphu, i-geometry kanye nesivinini sentwasahlobo) esifaneleka kakhulu ekulinganiseni izakhiwo zezinto ezithambile namasampula ebhayoloji. Le ndlela ithuthukisa ukuzwela kanye nokunemba kokulinganisa okunembile kwezinto ezithambile kakhulu ze-lehfilcon A, ene-modulus ephansi kakhulu yokuqina endaweni engaphezulu (kufika ku-2 kPa) kanye nokuqina okuphezulu kakhulu endaweni engaphakathi (cishe i-100%) yamanzi. Imiphumela yocwaningo lobuso ayzange iveze kuphela izakhiwo zobuso ezithambile kakhulu zelensi ye-lehfilcon A, kodwa futhi ibonise ukuthi i-modulus yamabhulashi e-polymer ahlanganisiwe yayifana neye-substrate ye-silicon-hydrogen. Le ndlela yokuchaza ubuso ingasetshenziswa kwezinye izinto ezithambile kakhulu namadivayisi ezokwelapha.
Izakhiwo zemishini zezinto ezenzelwe ukuthintana ngqo nezicubu eziphilayo zivame ukunqunywa yindawo ezungezile. Ukufana okuphelele kwalezi zakhiwo zezinto kusiza ukufeza izici zomtholampilo ezifiselekayo zezinto ngaphandle kokubangela izimpendulo ezimbi zamaseli1,2,3. Ezintweni ezilinganayo ngobuningi, ukuhlukaniswa kwezakhiwo zemishini kulula kakhulu ngenxa yokutholakala kwezinqubo ezijwayelekile nezindlela zokuhlola (isb., i-microindentation4,5,6). Kodwa-ke, ezintweni ezithambile kakhulu njengejeli, ama-hydrogel, ama-biopolymer, amaseli aphilayo, njll., lezi zindlela zokuhlola ngokuvamile azisebenzi ngenxa yemikhawulo yokuxazulula ukulinganisa kanye nokungafani kwezinye izinto7. Eminyakeni edlule, izindlela zendabuko zokufaka i-indent zishintshiwe futhi zaguqulwa ukuze zichaze uhla olubanzi lwezinto ezithambile, kodwa izindlela eziningi zisabhekene nokushiyeka okukhulu okunciphisa ukusetshenziswa kwazo8,9,10,11,12,13. Ukuntuleka kwezindlela zokuhlola ezikhethekile ezingachaza ngokunembile nangokuthembekile izakhiwo zemishini zezinto ezithambile kakhulu kanye nezendlalelo ezingaphezulu kunciphisa kakhulu ukusetshenziswa kwazo ezisetshenzisweni ezahlukene.
Emsebenzini wethu wangaphambilini, sethule ilensi yokuxhumana ye-lehfilcon A (CL), into ethambile engafani enazo zonke izakhiwo zobuso ezithambile kakhulu ezithathwe kumiklamo ye-biomimetic engase iphefumulelwe ubuso be-cornea yeso. Le nto yezinto eziphilayo yathuthukiswa ngokuxhunyelelwa ungqimba lwe-polymer oluhlanganisiwe, oluhlanganisiwe lwe-poly(2-methacryloyloxyethylphosphorylcholine (MPC)) (PMPC) ku-silicone hydrogel (SiHy) 15 eyenzelwe amadivayisi ezokwelapha ngokusekelwe. Le nqubo yokuxhunyelelwa idala ungqimba ebusweni oluqukethe isakhiwo sebhulashi le-polymeric elithambile kakhulu nelinwebeka kakhulu. Umsebenzi wethu wangaphambilini uqinisekisile ukuthi isakhiwo se-biomimetic se-lehfilcon A CL sinikeza izakhiwo zobuso eziphezulu njengokukhushulwa okuthuthukisiwe kokumanzisa nokungcola, ukwanda kokuthambisa, kanye nokuncipha kokunamathela kwamaseli namagciwane15,16. Ngaphezu kwalokho, ukusetshenziswa nokuthuthukiswa kwale nto yezinto eziphilayo kusikisela nokwanda okwengeziwe kwamanye amadivayisi ezokwelapha. Ngakho-ke, kubalulekile ukuchaza izakhiwo ezingaphezulu zale nto ethambile kakhulu nokuqonda ukusebenzisana kwayo ngomshini neso ukuze kudalwe isisekelo solwazi oluphelele lokusekela intuthuko kanye nezinhlelo zokusebenza zesikhathi esizayo. Amalensi amaningi okuxhumana e-SiHy atholakala emakethe akhiwe yingxube efanayo yama-polymer athanda amanzi kanye nama-hydrophobic akha isakhiwo sezinto ezifanayo17. Izifundo eziningana zenziwe ukuze kuhlolwe izakhiwo zawo zomshini kusetshenziswa izindlela zokuhlola zokucindezela zendabuko, ukucindezela kanye ne-microindentation18,19,20,21. Kodwa-ke, umklamo omusha we-biomimetic we-lehfilcon A CL wenza kube yinto ehlukile engafani lapho izakhiwo zomshini zezakhiwo zamabhulashi e-polymer ezinamagatsha zihluka kakhulu kunezo ze-substrate yesisekelo se-SiHy. Ngakho-ke, kunzima kakhulu ukulinganisa ngokunembile lezi zakhiwo kusetshenziswa izindlela ezivamile kanye ne-indentation. Indlela ethembisayo isebenzisa indlela yokuhlola i-nanoindentation esetshenziswa ku-atomic force microscopy (AFM), indlela esetshenziswe ukunquma izakhiwo zomshini zezinto ezithambile ze-viscoelastic ezifana namaseli ezinto eziphilayo kanye nezicubu, kanye nama-polymer athambile22,23,24,25. ,26,27,28,29,30. Ku-nanoindentation ye-AFM, izisekelo zokuhlolwa kwe-nanoindentation zihlanganiswa nentuthuko yakamuva kubuchwepheshe be-AFM ukuze kuhlinzekwe ukuzwela okukhulu kokulinganisa kanye nokuhlolwa kwezinto eziningi ezithambile ngokwemvelo31,32,33,34,35,36. Ngaphezu kwalokho, ubuchwepheshe bunikeza ezinye izinzuzo ezibalulekile ngokusebenzisa amajiyometri ahlukene, i-indenter kanye ne-probe kanye nokwenzeka kokuhlola ezindaweni ezahlukene zoketshezi.
Ukufakwa kwe-nano kwe-AFM kungahlukaniswa ngokwemibandela kube yizingxenye ezintathu eziyinhloko: (1) imishini (izinzwa, ama-detector, ama-probe, njll.); (2) amapharamitha okulinganisa (njengokuphoqa, ukufuduka, isivinini, usayizi we-ramp, njll.); (3) Ukucutshungulwa kwedatha (ukulungiswa kwesisekelo, ukulinganiswa kwephuzu lokuthinta, ukufakwa kwedatha, ukumodela, njll.). Inkinga ebalulekile ngale ndlela ukuthi izifundo eziningana ezincwadini ezisebenzisa i-nanoindentation ye-AFM zibika imiphumela ehlukene kakhulu yobuningi besampula/iseli/uhlobo olufanayo lwezinto37,38,39,40,41. Isibonelo, uLekka et al. Ithonya le-geometry ye-probe ye-AFM ku-modulus kaYoung elinganisiwe yamasampula e-hydrogel e-homogeneous mechanically kanye namaseli angafani lafundwa futhi laqhathaniswa. Babika ukuthi amanani e-modulus ​​ancike kakhulu ekukhetheni i-cantilever kanye nesimo se-tip, ngenani eliphakeme kakhulu le-probe efana ne-pyramid kanye nenani eliphansi kakhulu elingu-42 le-probe eyindilinga. Ngokufanayo, uSelhuber-Unkel et al. Kuye kwaboniswa ukuthi ijubane le-indenter, usayizi we-indenter kanye nobukhulu bamasampula e-polyacrylamide (PAAM) kuthinta kanjani i-modulus ye-Young elinganiswa yi-nanoindentation ye-ACM43. Esinye isici esiyinkimbinkimbi ukuntuleka kwezinto zokuhlola ze-modulus ezijwayelekile eziphansi kakhulu kanye nezinqubo zokuhlola zamahhala. Lokhu kwenza kube nzima kakhulu ukuthola imiphumela enembile ngokuzethemba. Kodwa-ke, le ndlela iwusizo kakhulu ekulinganisweni okuhlobene kanye nokuhlolwa kokuqhathanisa phakathi kwezinhlobo ezifanayo zesampula, isibonelo ukusebenzisa i-nanoindentation ye-AFM ukuhlukanisa amaseli ajwayelekile kumaseli omdlavuza 44, 45.
Uma uhlola izinto ezithambile nge-nanoindentation ye-AFM, umthetho ojwayelekile wesithupha ukusebenzisa i-probe ene-constant yentwasahlobo ephansi (k) ehambisana eduze ne-modulus yesampula kanye ne-hemispherical/round tip ukuze i-probe yokuqala ingabhobozi izindawo zesampula lapho ithintana okokuqala nezinto ezithambile. Kubalulekile futhi ukuthi isignali yokuphambuka ekhiqizwa yi-probe ibe namandla ngokwanele ukuze itholakale uhlelo lwe-laser detector24,34,46,47. Endabeni yamaseli athambile kakhulu, izicubu nama-gel, enye inselele ukunqoba amandla okunamathela phakathi kwe-probe kanye nendawo yesampula ukuqinisekisa izilinganiso eziphindaphindwayo nezithembekile48,49,50. Kuze kube muva nje, umsebenzi omningi we-nanoindentation ye-AFM ugxile ekufundweni kokuziphatha kwemishini kwamaseli ebhayoloji, izicubu, ama-gel, ama-hydrogel, nama-biomolecule kusetshenziswa ama-probe amakhulu kakhulu, avame ukubizwa ngokuthi ama-colloidal probes (CPs). , 47, 51, 52, 53, 54, 55. Lawa ma-tip anobubanzi obungu-1 kuya ku-50 µm futhi avame ukwenziwa ngengilazi ye-borosilicate, i-polymethyl methacrylate (PMMA), i-polystyrene (PS), i-silicon dioxide (SiO2) kanye ne-diamond-like carbon (DLC). Nakuba i-CP-AFM nanoindentation ivame ukuba yindlela yokuqala yokuchaza isampula ethambile, inezinkinga zayo kanye nemikhawulo yayo. Ukusetshenziswa kwamaphuzu amakhulu ayindilinga anobukhulu be-micron kwandisa indawo yokuxhumana ephelele yesihloko nesampula futhi kuholela ekulahlekelweni okukhulu kwesisombululo sendawo. Kumasampula athambile, angalingani, lapho izakhiwo zemishini zezinto zasendaweni zingase zihluke kakhulu kunesilinganiso endaweni ebanzi, i-CP indentation ingafihla noma yikuphi ukungalingani kwezakhiwo esikalini sendawo52. Ama-Colloidal probes ngokuvamile enziwa ngokunamathisela ama-colloidal sphere anobukhulu be-micron kuma-cantilever angenama-tip usebenzisa ama-epoxy adhesives. Inqubo yokukhiqiza ngokwayo igcwele izinkinga eziningi futhi ingaholela ekungahambelani enqubweni yokulinganisa i-probe. Ngaphezu kwalokho, ubukhulu kanye nesisindo sezinhlayiya ze-colloidal kuthinta ngqo amapharamitha okulinganisa ayinhloko e-cantilever, njengemvamisa yokuzwakala, ukuqina kwentwasahlobo, kanye nokuzwela kokuphambuka56,57,58. Ngakho-ke, izindlela ezisetshenziswa kakhulu ze-AFM probes ezivamile, njengokulinganisa izinga lokushisa, zingase zinganikezi ukulinganisa okunembile kwe-CP, futhi ezinye izindlela zingadingeka ukwenza lokhu kulungisa57, 59, 60, 61. Ukuhlolwa okujwayelekile kwe-CP indentation kusebenzisa i-cantilever enkulu deviations ukutadisha izakhiwo zamasampula athambile, okudala enye inkinga lapho kulinganiswa ukuziphatha okungeyona i-linear kwe-cantilever ekuphambukeni okukhulu kakhulu62,63,64. Izindlela zesimanje ze-colloidal probe indentation ngokuvamile zicabangela i-geometry ye-cantilever esetshenziselwa ukulinganisa i-probe, kodwa azinaki ithonya lezinhlayiya ze-colloidal, okudala ukungaqiniseki okwengeziwe ngokunemba kwendlela38,61. Ngokufanayo, i-elastic moduli ebalwa ngokufakwa kwemodeli yokuxhumana incike ngqo ku-geometry ye-indentation probe, futhi ukungafani phakathi kwezici ze-tip kanye nesampula kungaholela ekunganeni27, 65, 66, 67, 68. Eminye imisebenzi yakamuva kaSpencer et al. Izici okufanele zicatshangelwe lapho kuchazwa amabhulashi athambile e-polymer kusetshenziswa indlela ye-CP-AFM nanoindentation ziqokonyiswe. Babike ukuthi ukugcinwa koketshezi oluqinile emabhulashini e-polymer njengomsebenzi wejubane kuphumela ekwandeni komthwalo wekhanda ngakho-ke izilinganiso ezahlukene zezakhiwo ezincike kwisivinini30,69,70,71.
Kulesi sifundo, sichaze i-modulus engaphezulu kwezinto ezithambile kakhulu ezinwebeka kakhulu ze-lehfilcon A CL sisebenzisa indlela ye-nanoindentation ye-AFM eguquliwe. Njengoba sinikezwe izakhiwo kanye nesakhiwo esisha sale nto, ububanzi bokuzwela bendlela yendabuko yokunwebeka abwanele ngokusobala ukuchaza i-modulus yale nto ethambile kakhulu, ngakho-ke kuyadingeka ukusebenzisa indlela ye-nanoindentation ye-AFM enozwela oluphezulu kanye nezinga lokuzwela eliphansi. Ngemva kokubukeza ukushiyeka nezinkinga zamasu e-nanoindentation e-colloidal AFM probe akhona, sibonisa ukuthi kungani sikhethe i-probe ye-AFM encane, eyenzelwe ngokwezifiso ukuqeda ukuzwela, umsindo wangemuva, iphuzu lokuxhumana eliqondile, ukukala i-velocity modulus yezinto ezithambile ezingafani njengokuxhomekeka kokugcinwa koketshezi. kanye nokulinganisa okunembile. Ngaphezu kwalokho, sikwazile ukulinganisa ngokunembile ukuma nobukhulu be-indentation tip, okusivumela ukuthi sisebenzise imodeli yokulingana kwe-cone-sphere ukunquma i-modulus yokuqina ngaphandle kokuhlola indawo yokuxhumana ye-tip nezinto. Izinkolelo ezimbili ezingacacile ezilinganiswa kulo msebenzi yizakhiwo zezinto ezinwebeka ngokuphelele kanye ne-modulus engancikile ekujuleni kwe-indentation. Sisebenzisa le ndlela, siqale sahlola amazinga athambile kakhulu nge-modulus eyaziwayo ukuze silinganise indlela, sabe sesisebenzisa le ndlela ukuchaza izindawo zezinto ezimbili ezahlukene ze-contact lens. Le ndlela yokuchaza izindawo ze-AFM nanoindentation ezinozwela olukhuphukile kulindeleke ukuthi isebenze ezinhlobonhlobo zezinto ze-biomimetic heterogeneous ultrasoft ezinokusetshenziswa okungenzeka kumadivayisi ezokwelapha kanye nezinhlelo zokusebenza ze-biomedical.
I-Lehfilcon A contact lens (Alcon, Fort Worth, Texas, USA) kanye ne-silicone hydrogel substrates yazo zakhethwa ukuze kwenziwe izivivinyo ze-nanoindentation. Kusetshenziswe i-lens mount eklanyelwe ngokukhethekile ekuhlolweni. Ukuze kufakwe ilensi ukuze kuhlolwe, yabekwa ngokucophelela esitendini esimise okwe-dome, kwaqinisekiswa ukuthi akukho ma-bubble omoya angena ngaphakathi, bese iqiniswa ngemiphetho. Imbobo entweni efakwe phezulu kwesibambi selensi inikeza ukufinyelela esikhungweni se-optical selensi ukuze kwenziwe izivivinyo ze-nanoindentation ngenkathi ibambe uketshezi endaweni yalo. Lokhu kugcina amalensi enamanzi aphelele. Isixazululo sokupakisha selensi yokuxhumana esingu-500 μl sasetshenziswa njengesixazululo sokuhlola. Ukuze kuqinisekiswe imiphumela yobuningi, ama-hydrogel e-polyacrylamide (PAAM) angasetshenziswanga athengiswayo alungiswa kusuka ku-polyacrylamide-co-methylene-bisacrylamide composition (100 mm Petrisoft Petri dishes, Matrigen, Irvine, CA, USA), i-modulus eyaziwayo ye-elastic ye-1 kPa. Sebenzisa amaconsi angu-4-5 (cishe angu-125 µl) e-phosphate buffered saline (i-PBS evela eCorning Life Sciences, eTewkesbury, MA, e-USA) kanye neconsi eli-1 lesisombululo se-OPTI-FREE Puremoist contact lens (e-Alcon, eVaud, e-TX, e-USA). ) ku-interface ye-AFM hydrogel-probe.
Amasampula e-Lehfilcon A CL kanye ne-SiHy substrates aboniswe kusetshenziswa uhlelo lwe-FEI Quanta 250 Field Emission Scanning Electron Microscope (FEG SEM) oluhlonyiswe nge-Scanning Transmission Electron Microscope (STEM). Ukuze kulungiswe amasampula, amalensi aqale agezwa ngamanzi futhi anqunywe abe yizicucu ezimise okwephayi. Ukuze kufezwe umehluko ohlukile phakathi kwezingxenye zesampula eziphila emanzini kanye neziphila emanzini, kwasetshenziswa isixazululo esizinzile esingu-0.10% se-RuO4 njengodayi, lapho amasampula acwiliswa khona imizuzu engama-30. Ukufaka idayi kwe-lehfilcon A CL RuO4 kubalulekile hhayi nje kuphela ekufezeni umehluko othuthukisiwe, kodwa futhi kusiza ekugcineni isakhiwo samabhulashi e-polymer ahlanganisiwe ngesimo sawo sokuqala, abonakala ezithombeni ze-STEM. Abe esegezwa futhi ancishiswa emanzini ochungechungeni lwezingxube ze-ethanol/amanzi ngokwanda kokuhlushwa kwe-ethanol. Amasampula abe esephonswa nge-EMBEd 812/Araldite epoxy, eyaphola ubusuku bonke ku-70°C. Amabhulokhi esampula atholwe yi-resin polymerization asikwa nge-ultramicrotome, futhi izingxenye ezincane ezavela zabonakala nge-STEM detector kwimodi ye-vacuum ephansi ku-voltage esheshisa engu-30 kV. Uhlelo olufanayo lwe-SEM lwasetshenziswa ekuchazeni okuningiliziwe kwe-PFQNM-LC-A-CAL AFM probe (Bruker Nano, Santa Barbara, CA, USA). Izithombe ze-SEM ze-probe ye-AFM zitholwe kwimodi evamile ye-vacuum ephezulu ene-voltage esheshisa engu-30 kV. Thola izithombe ngama-engeli ahlukene kanye nokukhulisa ukuze urekhode yonke imininingwane yesimo nosayizi we-pope ye-AFM. Zonke izilinganiso ze-pope ezithakaselwayo ezithombeni zilinganiswe ngedijithali.
I-Dimension FastScan Bio Icon atomic force microscope (Bruker Nano, Santa Barbara, CA, USA) enemodi ethi “PeakForce QNM in Fluid” yasetshenziswa ukubona ngeso lengqondo kanye nokuthatha amasampula e-lehfilcon e-CL, i-SiHy substrate, kanye ne-PAAm hydrogel. Kokuhlolwa kwezithombe, i-PEAKFORCE-HIRS-FA probe (Bruker) ene-nominal tip radius engu-1 nm yasetshenziswa ukuthwebula izithombe ezinesinqumo esiphezulu sesampula ngesilinganiso sokuskena esingu-0.50 Hz. Zonke izithombe zathathwa ngesisombululo samanzi.
Ukuhlolwa kwe-nanoindentation ye-AFM kwenziwe kusetshenziswa i-probe ye-PFQNM-LC-A-CAL (Bruker). I-probe ye-AFM inesihloko se-silicon ku-cantilever ye-nitride engu-345 nm ubukhulu, ubude obungu-54 µm kanye nobubanzi obungu-4.5 µm ngemvamisa ye-resonant engu-45 kHz. Yenzelwe ngqo ukuchaza nokwenza izilinganiso ze-nanomechanical ezilinganiselwe kumasampula athambile e-biological. Ama-sensor alinganiswa ngawodwana efektri ngezilungiselelo zentwasahlobo ezilinganisiwe ngaphambilini. Ama-spring constants ama-probe asetshenziswe kulolu cwaningo ayephakathi kuka-0.05–0.1 N/m. Ukuze kutholakale ngokunembile ukuma nosayizi wesihloko, i-probe ichazwe ngokuningiliziwe kusetshenziswa i-SEM. Ku-Fig. Isithombe 1a sibonisa i-electron micrograph enesisombululo esiphezulu, ephansi yokuskena i-probe ye-PFQNM-LC-A-CAL, enikeza umbono ophelele womklamo we-probe. Ku-Fig. 1b sibonisa umbono okhulisiwe wengxenye ephezulu yesihloko se-probe, enikeza ulwazi mayelana nokuma nosayizi wesihloko. Ekugcineni okukhulu, inaliti iyi-hemisphere engaba ngu-140 nm ububanzi (Isithombe 1c). Ngaphansi kwalokhu, isihloko siyancipha sibe yisimo esiyindilinga, sifinyelele ubude obulinganisiwe obungaba ngu-500 nm. Ngaphandle kwesifunda esinciphile, isihloko siyisilinda futhi siphela ngobude obuphelele besihloko esingu-1.18 µm. Lena yingxenye eyinhloko esebenzayo yesihloko se-probe. Ngaphezu kwalokho, i-probe enkulu eyindilinga ye-polystyrene (PS) (Novascan Technologies, Inc., Boone, Iowa, USA) enobubanzi besihloko obungu-45 µm kanye ne-spring constant engu-2 N/m nayo yasetshenziswa ekuhlolweni njenge-probe ye-colloidal. nge-probe ye-PFQNM-LC-A-CAL engu-140 nm yokuqhathanisa.
Kubikwe ukuthi uketshezi lungabanjwa phakathi kweprobe ye-AFM kanye nesakhiwo sebhulashi le-polymer ngesikhathi sokugoba kwe-nano, okuzosebenzisa amandla aphezulu kuprobe ye-AFM ngaphambi kokuba ithinte ubuso 69. Lo mphumela wokugoba kwe-viscous ngenxa yokugcinwa koketshezi ungashintsha indawo ebonakalayo yokuxhumana, ngaleyo ndlela kuthinte ukulinganiswa kwe-surface modulus. Ukuze kufundwe umphumela we-probe geometry kanye nesivinini sokugoba ekugcinweni koketshezi, ama-curve amandla okugoba adwetshwe amasampula e-lehfilcon A CL kusetshenziswa iprobe yobubanzi obungu-140 nm ngamazinga okuhamba aqhubekayo angu-1 µm/s kanye no-2 µm/s. ububanzi beprobe bungu-45 µm, ukusetha kwamandla aqinile okungu-6 nN kufinyelelwe ku-1 µm/s. Ukuhlolwa ngeprobe engu-140 nm ububanzi kwenziwe ngesivinini sokugoba esingu-1 µm/s kanye namandla asethi angu-300 pN, akhethwe ukudala ingcindezi yokuxhumana ngaphakathi kobubanzi be-physiological (1–8 kPa) yeso elingaphezulu. ingcindezi 72. Amasampula enziwe ngomumo ethambile e-PAA hydrogel anomfutho we-1 kPa ahlolwe amandla okungena angama-50 pN ngesivinini esingu-1 μm/s kusetshenziswa i-probe enobubanzi obungu-140 nm.
Njengoba ubude bengxenye eyindilinga yesihloko seprobe ye-PFQNM-LC-A-CAL bucishe bube ngu-500 nm, kunoma yikuphi ukujula kokugoba < 500 nm kungacatshangwa ngokuphephile ukuthi i-geometry yeprobe ngesikhathi sokugoba izohlala iqinisile esimweni sayo sekhoni. Ngaphezu kwalokho, kucatshangwa ukuthi ubuso bezinto ezivivinywayo buzobonisa impendulo eguquguqukayo, ezoqinisekiswa futhi ezigabeni ezilandelayo. Ngakho-ke, kuye ngesimo nosayizi wesihloko, sikhethe imodeli yokulinganisa i-cone-sphere eyenziwe nguBriscoe, uSebastian no-Adams, etholakala kusofthiwe yomthengisi, ukucubungula izivivinyo zethu ze-nanoindentation ze-AFM (NanoScope). Isofthiwe yokuhlaziya idatha yokuhlukanisa, iBruker) 73. Imodeli ichaza ubudlelwano be-force-displacement F(δ) yekhoni enesici se-apex esiyindilinga. Ku-fig. Isithombe 2 sibonisa i-geometry yokuxhumana ngesikhathi sokusebenzisana kwekhoni eqinile nesihloko esiyindilinga, lapho u-R kuyirediyasi yesihloko esiyindilinga, u-a iyirediyasi yokuxhumana, u-b iyirediyasi yokuxhumana ekugcineni kwesihloko esiyindilinga, u-δ iyirediyasi yokuxhumana. ukujula kokujiya, u-θ uyi-half-angle yekhoni. Isithombe se-SEM salesi sigameko sibonisa ngokusobala ukuthi isihloko esiyindilinga esingu-140 nm ububanzi sihlangana ngendlela eqondile sibe yikhoni, ngakho-ke lapha u-b uchazwa kuphela ngo-R, okungukuthi u-b = u-R cos θ. Isofthiwe enikezwa ngumthengisi inikeza ubudlelwano bekhoni-sphere ukuze kubalwe amanani e-modulus (E) ka-Young kusuka kudatha yokuhlukaniswa kwamandla ethatha u-a > b. Ubudlelwano:
lapho u-F ewukugoba, u-E ewumodulus kaYoung, u-ν ewusilinganiso sikaPoisson. Irediyasi yokuxhumana u-a ingalinganiswa kusetshenziswa:
Uhlelo lwe-geometry yokuxhumana kwekhoni eqinile enesihloko esiyindilinga esicindezelwe ezintweni zelensi yokuxhumana yeLefilcon enesendlalelo sangaphezulu samabhulashi e-polymer ahlanganisiwe.
Uma u-≤ b, ubudlelwano buncipha bube yi-equation ye-indenter eyindilinga evamile;
Sikholelwa ukuthi ukusebenzisana kwe-probe yokugoba nesakhiwo esinamagatsha sebhulashi le-polymer le-PMPC kuzokwenza ukuthi i-rediyasi yokuxhumana u-a ibe nkulu kune-rediyasi yokuxhumana eyindilinga u-b. Ngakho-ke, kuzo zonke izilinganiso zokulinganisa ze-modulus enwebekayo ezenziwe kulolu cwaningo, sisebenzise ukuncika okutholakale ku-a > b.
Izinto ze-biomimetic ezithambile kakhulu ezifundwe kulolu cwaningo zathathwa izithombe ngokuphelele kusetshenziswa i-scanning transmission electron microscopy (STEM) yesigaba esiphambene nesampula kanye ne-atomic force microscopy (AFM) yobuso. Lokhu kuchazwa kobuso okuningiliziwe kwenziwe njengokwelulwa komsebenzi wethu oshicilelwe ngaphambilini, lapho sathola khona ukuthi isakhiwo sebhulashi le-polymeric elinobubanzi obuguquguqukayo bobuso be-lehfilcon A CL obuguquliwe be-PMPC sibonise izakhiwo ezifanayo zemishini nezicubu ze-cornea zemvelo 14. Ngenxa yalesi sizathu, sibhekisela ezindaweni ze-contact lens njengezinto ze-biomimetic14. Ku-Fig. 3a,b sibonisa izingxenye eziphambene zezakhiwo zebhulashi le-polymer le-PMPC elinobubanzi ebusweni be-substrate ye-lehfilcon A CL kanye ne-substrate ye-SiHy engalashwanga, ngokulandelana. Izindawo zombili zamasampula zahlaziywa kabanzi kusetshenziswa izithombe ze-AFM ezinesinqumo esiphezulu, okwaqinisekisa imiphumela yokuhlaziywa kwe-STEM (Fig. 3c, d). Uma zihlanganiswa, lezi zithombe zinikeza ubude obulinganiselwe besakhiwo sebhulashi le-polymer le-PMPC elinobubanzi obungu-300–400 nm, okubalulekile ekuchazeni izilinganiso ze-AFM nanoindentation. Okunye okubalulekile okubonwe ezithombeni ukuthi isakhiwo sobuso sonke sezinto ze-CL biomimetic sihlukile ngokwesimo sezinto ze-substrate ze-SiHy. Lo mehluko ekubunjweni kwazo kobuso ungabonakala ngesikhathi sokusebenzisana kwazo ngomshini ne-indenting AFM probe futhi kamuva kumanani e-modulus alinganisiwe.
Izithombe ze-STEM ezinqamula isigaba (a) i-lehfilcon A CL kanye (b) ne-SiHy substrate. Ibha yesikali, 500 nm. Izithombe ze-AFM zobuso be-lehfilcon A CL substrate (c) kanye ne-base SiHy substrate (d) (3 µm × 3 µm).
Ama-polymer aphefumulelwe yi-bio kanye nezakhiwo zamabhulashi e-polymer zithambile ngokwemvelo futhi ziye zafundwa kabanzi futhi zasetshenziswa ezinhlotsheni ezahlukene ze-biomedical74,75,76,77. Ngakho-ke, kubalulekile ukusebenzisa indlela ye-AFM nanoindentation, engalinganisa ngokunembile nangokuthembekile izakhiwo zazo zemishini. Kodwa ngesikhathi esifanayo, izakhiwo ezihlukile zalezi zinto ezithambile kakhulu, njenge-modulus ephansi kakhulu, okuqukethwe okuphezulu koketshezi kanye nokuqina okuphezulu, kuvame ukwenza kube nzima ukukhetha izinto ezifanele, ukuma kanye nesimo se-probe yokunweba. Lokhu kubalulekile ukuze i-indenter ingabhobozi ubuso obuthambile besampula, okungaholela emaphutheni ekunqumeni indawo yokuxhumana nobuso kanye nendawo yokuxhumana.
Ngenxa yalokhu, ukuqonda okuphelele kwesimo sezinto ze-biomimetic ezithambile kakhulu (i-lehfilcon A CL) kubalulekile. Ulwazi mayelana nosayizi kanye nesakhiwo samabhulashi e-polymer ahlanganisiwe atholwe kusetshenziswa indlela yokuthwebula izithombe lunikeza isisekelo sokuchazwa komshini wobuso kusetshenziswa amasu e-AFM nanoindentation. Esikhundleni sama-probe e-colloidal ayindilinga anobukhulu be-micron, sikhethe i-PFQNM-LC-A-CAL silicon nitride probe (Bruker) enobubanzi obuyi-tip obungu-140 nm, eyenzelwe ngokukhethekile ukumaka okulinganiselwe kwezakhiwo zomshini zamasampula ebhayoloji 78, 79, 80, 81, 82, 83, 84. Isizathu sokusebenzisa ama-probe abukhali uma kuqhathaniswa nama-probe e-colloidal avamile singachazwa ngezici zesakhiwo sezinto. Uma kuqhathaniswa usayizi wesihloko seprobe (~140 nm) namabhulashi e-polymer ahlanganisiwe ebusweni be-CL lehfilcon A, aboniswe ku-Fig. 3a, kungaphethwa ngokuthi isihloko sikhulu ngokwanele ukuthi sithintane ngqo nalezi zakhiwo zamabhulashi, okunciphisa amathuba okubhoboza isihloko kuzo. Ukuze kuboniswe leli phuzu, ku-Fig. 4 isithombe se-STEM se-lehfilcon A CL kanye nesihloko sokugoba seprobe ye-AFM (esidwetshwe esikalini).
I-schematic ekhombisa isithombe se-STEM se-lehfilcon A CL kanye ne-probe yokuncishiswa kwe-ACM (edwetshwe esikalini).
Ngaphezu kwalokho, usayizi we-tip ongu-140 nm mncane ngokwanele ukugwema ingozi yanoma yimiphi imiphumela yokuphuma okunamathelayo ebikwe ngaphambilini ngamabhulashi e-polymer akhiqizwe yindlela ye-CP-AFM nanoindentation69,71. Sicabanga ukuthi ngenxa yesimo esikhethekile se-cone-spherical kanye nosayizi omncane walesi sihloko se-AFM (Umfanekiso 1), uhlobo lwe-force curve olukhiqizwa yi-lehfilcon A CL nanoindentation ngeke luncike esivinini sokugoba noma isivinini sokulayisha/sokukhipha. Ngakho-ke, aluthintwa yimiphumela ye-poroelastic. Ukuze kuhlolwe lo mbono, amasampula e-lehfilcon A CL agobalwe ngamandla aphezulu aqinile kusetshenziswa i-PFQNM-LC-A-CAL probe, kodwa ngamajubane amabili ahlukene, futhi ama-tensile force curve aphumelayo asetshenziswa ukuhlela amandla (nN) ekuhlukaniseni (µm) aboniswe ku-Figure 5a. Kusobala ukuthi amajika amandla ngesikhathi sokulayisha nokukhipha ahlangana ngokuphelele, futhi abukho ubufakazi obucacile bokuthi ukucheba kwamandla ekujuleni kwe-zero indentation kuyanda ngesivinini se-indentation esithombeni, okuphakamisa ukuthi izakhi zebhulashi ngazinye zazibonakala ngaphandle komphumela we-poroelastic. Ngokuphambene nalokho, imiphumela yokugcina uketshezi (imiphumela ye-viscous extrusion kanye ne-poroelasticity) iyabonakala ku-probe ye-AFM engu-45 µm ububanzi ngesivinini esifanayo se-indentation futhi igqanyiswa yi-hysteresis phakathi kwamajika okwelula nokuhoxa, njengoba kuboniswe kuMfanekiso 5b. Le miphumela isekela umbono futhi isikisela ukuthi ama-probe angu-140 nm ububanzi ayisinqumo esihle sokuhlukanisa izindawo ezinjalo ezithambile.
i-lehfilcon A Ama-Cl indentation force curves asebenzisa i-ACM; (a) ukusebenzisa i-probe enobubanzi obungu-140 nm ngamanani amabili okulayisha, okubonisa ukungabikho komphumela we-poroelastic ngesikhathi sokugoba kobuso; (b) ukusebenzisa ama-probe anobubanzi obungu-45 µm no-140 nm. s kukhombisa imiphumela ye-viscous extrusion kanye ne-poroelasticity yama-probe amakhulu uma kuqhathaniswa nama-probe amancane.
Ukuze kuchazwe izindawo ezithambile kakhulu, izindlela ze-AFM nanoindentation kumele zibe ne-probe engcono kakhulu yokufunda izakhiwo zezinto ezifundwayo. Ngaphezu kokuma kwe-tip nosayizi, ukuzwela kohlelo lwe-AFM detector, ukuzwela ekuphambukeni kwe-tip endaweni yokuhlola, kanye nokuqina kwe-cantilever kudlala indima ebalulekile ekunqumeni ukunemba nokuthembeka kokulinganiswa kwe-nanoindentation. Kuhlelo lwethu lwe-AFM, umkhawulo wokuthola we-Position Sensitive Detector (PSD) cishe u-0.5 mV futhi usekelwe esilinganisweni sentwasahlobo esilinganisiwe kanye nokuzwela okubalwa kokuphambuka koketshezi kwe-probe ye-PFQNM-LC-A-CAL, ehambisana nokuzwela komthwalo wethiyori. kungaphansi kuka-0.1 pN. Ngakho-ke, le ndlela ivumela ukukalwa kwamandla amancane okungena ≤ 0.1 pN ngaphandle kwengxenye yomsindo we-peripheral. Kodwa-ke, cishe akunakwenzeka ukuthi uhlelo lwe-AFM lunciphise umsindo we-peripheral kuleli zinga ngenxa yezici ezifana nokudlidliza kwemishini kanye nokuguquguquka koketshezi. Lezi zici zikhawulela ukuzwela okuphelele kwendlela ye-nanoindentation ye-AFM futhi ziholela esignalini yomsindo wangemuva cishe engu-≤ 10 pN. Ukuze kuchazwe ubuso, amasampula e-lehfilcon A CL kanye ne-SiHy substrate afakwe ngaphakathi ngaphansi kwezimo ezimanzi ngokuphelele kusetshenziswa i-probe engu-140 nm ukuze kuchazwe i-SEM, futhi ama-force curve aphumayo abekwe phakathi kwamandla (pN) kanye nengcindezi. I-separation plot (µm) iboniswe ku-Figure 6a. Uma kuqhathaniswa ne-substrate yesisekelo se-SiHy, i-lehfilcon A CL force curve ikhombisa ngokucacile isigaba sokuguquka esiqala endaweni yokuxhumana nebhulashi le-polymer eliyifoloko futhi siphela ngoshintsho olubukhali ekuthinteni okumakwe kwe-slope kwesihloko nezinto ezingaphansi. Le ngxenye yokuguquka ye-force curve iqokomisa ukuziphatha okunwebekayo kwebhulashi le-polymer elihlanganisiwe ebusweni, njengoba kuboniswa yi-compression curve elandela eduze i-tension curve kanye nomehluko ezimpahleni zemishini phakathi kwesakhiwo sebhulashi nezinto ze-SiHy ezinkulu. Uma kuqhathaniswa i-lefilcon. Ukuhlukaniswa kobude obumaphakathi bebhulashi le-polymer elinamagatsha esithombeni se-STEM se-PCS (Isithombe 3a) kanye nejika layo lamandla eceleni kwe-abscissa ku-Isithombe 3a. 6a kukhombisa ukuthi indlela iyakwazi ukubona isihloko kanye ne-polymer enamagatsha efinyelela phezulu kakhulu kobuso. Ukuxhumana phakathi kwezakhiwo zamabhulashi. Ngaphezu kwalokho, ukugqagqana okuseduze kwama-force curves kubonisa ukungabikho komphumela wokugcina uketshezi. Kulesi simo, akukho ukunamathelana phakathi kwenaliti kanye nobuso besampula. Izingxenye eziphezulu kakhulu zama-force curves zamasampula amabili ziyagqagqana, okubonisa ukufana kwezakhiwo zemishini zezinto ze-substrate.
(a) Ama-AFM nanoindentation force curves e-lehfilcon A CL substrates kanye nama-SiHy substrates, (b) ama-force curves abonisa ukulinganisa indawo yokuxhumana kusetshenziswa indlela yomkhawulo womsindo wangemuva.
Ukuze kufundwe imininingwane ecacile yejika lamandla, ijika lokucindezeleka lesampula ye-lehfilcon A CL lihlelwe kabusha ku-Fig. 6b ngamandla aphezulu angu-50 pN eceleni kwe-y-axis. Le grafu inikeza ulwazi olubalulekile mayelana nomsindo wangemuva wokuqala. Umsindo usebangeni lika-±10 pN, elisetshenziselwa ukunquma ngokunembile iphuzu lokuxhumana nokubala ukujula kokungena. Njengoba kubikiwe ezincwadini, ukuhlonza amaphuzu okuxhumana kubalulekile ukuze kuhlolwe ngokunembile izakhiwo zezinto ezifana ne-modulus85. Indlela ehilela ukucubungula ngokuzenzakalela idatha yejika lamandla ibonise ukulingana okuthuthukisiwe phakathi kokufakwa kwedatha nokulinganisa inani lezinto ezithambile86. Kulo msebenzi, ukukhetha kwethu amaphuzu okuxhumana kulula futhi kunenjongo, kodwa kunemikhawulo yayo. Indlela yethu yokulondoloza yokunquma iphuzu lokuxhumana ingase iholele kumanani e-modulus alinganiswe ngokweqile ekujuleni okuncane kokungena (< 100 nm). Ukusetshenziswa kokutholwa kwe-touchpoint okusekelwe ku-algorithm kanye nokucubungula idatha okuzenzakalelayo kungaba ukuqhubeka kwalo msebenzi esikhathini esizayo ukuze kuthuthukiswe indlela yethu. Ngakho-ke, ngomsindo wangemuva ongaphakathi olandelanayo ongu-±10 pN, sichaza iphuzu lokuxhumana njengephuzu lokuqala ledatha ku-x-axis ku-Figure 6b enenani elingu-≥10 pN. Ngemuva kwalokho, ngokuhambisana nomkhawulo womsindo ongu-10 pN, umugqa oqondile ezingeni lika-~0.27 µm uphawula iphuzu lokuxhumana nomphezulu, ngemva kwalokho ijika elinwebekayo liyaqhubeka kuze kube yilapho i-substrate ihlangana nokujula kokugoba okungu-~270 nm. Ngokuthakazelisayo, ngokusekelwe kusayizi wezici zebhulashi le-polymer elinegatsha (300–400 nm) elilinganiswe kusetshenziswa indlela yokuthwebula izithombe, ukujula kokugoba kwe-CL lehfilcon Isampula ebonwe kusetshenziswa indlela yokugoba komsindo wangemuva cishe ingu-270 nm, esondele kakhulu kusayizi wokulinganisa nge-STEM. Le miphumela iqinisekisa ngokwengeziwe ukuhambisana nokusebenza kwesimo nosayizi we-AFM probe tip yokugoba kwalesi sakhiwo sebhulashi le-polymer elinegatsha elithambile kakhulu nelithambile kakhulu. Le datha iphinde inikeze ubufakazi obuqinile bokusekela indlela yethu yokusebenzisa umsindo wangemuva njengomkhawulo wokukhomba amaphuzu okuxhumana. Ngakho-ke, noma yimiphi imiphumela yokulinganisa etholakala ekubunjweni kwezibalo kanye nokufakwa kwe-force curve kufanele ibe nembalo enembile.
Izilinganiso zobuningi ngezindlela ze-nanoindentation ze-AFM zincike ngokuphelele kumamodeli ezibalo asetshenziselwa ukukhethwa kwedatha kanye nokuhlaziywa okulandelayo. Ngakho-ke, kubalulekile ukucabangela zonke izici ezihlobene nokukhetha i-indenter, izakhiwo zezinto kanye nendlela yokusebenzisana kwazo ngaphambi kokukhetha imodeli ethile. Kulesi simo, i-tip geometry yachazwa ngokucophelela kusetshenziswa ama-micrograph e-SEM (Isithombe 1), futhi ngokusekelwe emiphumeleni, i-probe ye-nanoindenting ye-AFM engu-140 nm ububanzi ene-hard cone kanye ne-spherical tip geometry iyisinqumo esihle sokuchaza amasampula e-lehfilcon A CL79. Esinye isici esibalulekile okudingeka sihlolwe ngokucophelela ukuqina kwezinto ze-polymer ezivivinywayo. Nakuba idatha yokuqala ye-nanoindentation (Izithombe 5a no-6a) ichaza ngokucacile izici zokugqagqana kwama-tension and compression curves, okungukuthi, ukubuyiselwa okuphelele kwe-elastic kwezinto, kubaluleke kakhulu ukuqinisekisa uhlobo lwe-elastic kuphela lwabathintana nabo. Ngenxa yalokhu, kwenziwa ukugoba okubili okulandelanayo endaweni efanayo ebusweni besampula ye-lehfilcon A CL ngesilinganiso sokugoba esingu-1 µm/s ngaphansi kwezimo zokumanzisa okugcwele. Idatha yejika lamandla elivelayo iboniswe ku-Fig. 7 futhi, njengoba bekulindelekile, amajika okunwebeka kanye nokucindezelwa kwamaphrinta amabili acishe afane, okugqamisa ukuqina okuphezulu kwesakhiwo sebhulashi le-polymer elinegatsha.
Amajika amabili anamandla okugoba endaweni efanayo ebusweni be-lehfilcon A CL abonisa ukuqina okufanele kobuso belensi.
Ngokusekelwe olwazini olutholwe ezithombeni ze-SEM kanye ne-STEM ze-probe tip kanye ne-lehfilcon A CL surface, ngokulandelana, imodeli ye-cone-sphere iwukubonakaliswa okunengqondo kwezibalo kokuxhumana phakathi kwe-AFM probe tip kanye nezinto ze-polymer ezithambile ezivivinywayo. Ngaphezu kwalokho, kule modeli ye-cone-sphere, izibikezelo eziyisisekelo mayelana nezakhiwo ze-elastic zezinto ezishicilelwe ziyiqiniso kule nto entsha ye-biomimetic futhi zisetshenziselwa ukulinganisa i-elastic modulus.
Ngemva kokuhlolwa okuphelele kwendlela ye-nanoindentation ye-AFM kanye nezingxenye zayo, okuhlanganisa izakhiwo ze-indentation probe (ukuma, usayizi, kanye nokuqina kwentwasahlobo), ukuzwela (umsindo wangemuva kanye nokulinganisa indawo yokuxhumana), kanye namamodeli okufaka idatha (ukulinganiswa kwe-modulus yobuningi), le ndlela yasetshenziswa. chaza amasampula athambile kakhulu atholakala kwezentengiselwano ukuqinisekisa imiphumela yobuningi. I-hydrogel ye-polyacrylamide (PAAM) yezentengiselwano ene-modulus enwebekayo engu-1 kPa ihlolwe ngaphansi kwezimo ezimanzi kusetshenziswa i-probe engu-140 nm. Imininingwane yokuhlolwa kwemodyuli kanye nokubala inikezwe ku-Supplementary Information. Imiphumela ikhombisile ukuthi i-modulus ejwayelekile elinganisiwe yayingu-0.92 kPa, kanti ukuphambuka kwe-%RSD kanye nephesenti (%) kusuka ku-modulus eyaziwayo kwakungaphansi kuka-10%. Le miphumela iqinisekisa ukunemba kanye nokuphindaphindeka kwendlela ye-AFM nanoindentation esetshenziswe kulo msebenzi ukukala i-moduli yezinto ezithambile kakhulu. Ubuso besampula ze-lehfilcon A CL kanye nesisekelo se-SiHy kwachazwa kabanzi kusetshenziswa indlela efanayo ye-AFM nanoindentation ukuze kufundwe i-contact modulus ebonakalayo yendawo ethambile njengomsebenzi wokujula kwe-indentation. Ama-curve okuhlukanisa amandla okugoba akhiqizwa amasampula amathathu ohlobo ngalunye (n = 3; i-indentation eyodwa ngesampula) ngamandla angu-300 pN, isivinini esingu-1 µm/s, kanye nokumanziswa okugcwele. I-indentation force sharing curve yalinganiswa kusetshenziswa imodeli ye-cone-sphere. Ukuze kutholakale i-modulus encike ekujuleni kwe-indentation, ingxenye ebanzi engu-40 nm ye-force curve yabekwa ekukhuphukeni ngakunye okungu-20 nm kusukela endaweni yokuxhumana, futhi kwalinganiswa amanani e-modulus esinyathelweni ngasinye se-force curve. Spin Cy et al. Indlela efanayo isetshenziswe ukuchaza i-modulus gradient yamabhulashi e-polymer e-poly(lauryl methacrylate) (P12MA) kusetshenziswa i-colloidal AFM probe nanoindentation, futhi iyahambisana nedatha esebenzisa imodeli yokuxhumana ye-Hertz. Le ndlela inikeza uhlaka lwe-apparent contact modulus (kPa) uma kuqhathaniswa nokujula kwe-indentation (nm), njengoba kuboniswe ku-Figure 8, ekhombisa i-apparent contact modulus/depth gradient. I-elastic modulus ebaliwe yesampula ye-CL lehfilcon A isebangeni elingu-2–3 kPa ngaphakathi kwe-100 nm ephezulu yesampula, ngale kwalokho iqala ukwanda ngokujula. Ngakolunye uhlangothi, lapho kuhlolwa isisekelo se-SiHy ngaphandle kwefilimu efana nebhulashi ebusweni, ukujula okuphezulu kwe-indentation okufinyelelwe ngamandla angu-300 pN kungaphansi kuka-50 nm, kanti inani le-modulus elitholwe kudatha licishe libe ngu-400 kPa, okulingana namanani e-modulus kaYoung wezinto zobuningi.
I-contact modulus ebonakalayo (kPa) vs. ukujula kokugoba (nm) kwe-lehfilcon A CL kanye ne-SiHy substrates kusetshenziswa indlela ye-AFM nanoindentation ene-cone-sphere geometry ukukala i-modulus.
Ubuso obuphezulu besakhiwo esisha sebhulashi le-polymer elinegatsha le-biomimetic bubonisa i-modulus ephansi kakhulu yokunwebeka (2–3 kPa). Lokhu kuzohambisana nengxenye elengayo yamahhala yebhulashi le-polymer elinefoloko njengoba kuboniswe esithombeni se-STEM. Ngenkathi kukhona ubufakazi bokuthi i-modulus gradient iphezulu kakhulu emaphethelweni angaphandle e-CL, i-substrate eyinhloko ye-modulus ephezulu inethonya elikhulu. Kodwa-ke, i-100 nm ephezulu yobuso ingaphakathi kwama-20% wobude obuphelele bebhulashi le-polymer elinegatsha, ngakho-ke kunengqondo ukucabanga ukuthi amanani alinganisiwe e-modulus kulolu hlu lokujula kwe-indentation anembile kakhulu futhi awaxhomekile kakhulu emthonjeni wento engezansi.
Ngenxa yomklamo oyingqayizivele we-biomimetic wama-lens okuxhumana e-lehfilcon A, aqukethe izakhiwo zamabhulashi e-polymer e-PMPC ahlanganisiwe phezu kwezingxenye ze-SiHy, kunzima kakhulu ukuchaza ngokuthembekile izakhiwo zemishini zezakhiwo zawo zobuso sisebenzisa izindlela zokulinganisa zendabuko. Lapha sethula indlela ethuthukisiwe ye-AFM nanoindentation yokuchaza ngokunembile izinto ezithambile kakhulu njenge-lefilcon A enokuqukethwe kwamanzi amaningi kanye nokuqina okuphezulu kakhulu. Le ndlela isekelwe ekusetshenzisweni kwe-probe ye-AFM enobukhulu be-tip kanye ne-geometry ekhethwe ngokucophelela ukuze ifane nobukhulu besakhiwo sezici zobuso ezithambile kakhulu ezizonyatheliswa. Lokhu kuhlanganiswa kobukhulu phakathi kwe-probe nesakhiwo kunikeza ukuzwela okwandisiwe, okusivumela ukuthi silinganise i-modulus ephansi kanye nezakhiwo ezithambile ezingokwemvelo zezinto zamabhulashi e-polymer ahlanganisiwe, kungakhathaliseki imiphumela ye-poroelastic. Imiphumela ibonise ukuthi amabhulashi e-polymer e-PMPC ahlanganisiwe ahlukile abonakala ebusweni belensi ayene-modulus ethambile kakhulu (kufika ku-2 kPa) kanye nokuqina okuphezulu kakhulu (cishe u-100%) lapho ehlolwa endaweni enamanzi. Imiphumela ye-AFM nanoindentation isivumele nokuthi sichaze i-contact modulus/depth gradient ebonakalayo (30 kPa/200 nm) ebusweni belensi ye-biomimetic. Lokhu kugqama kungase kube ngenxa yomehluko we-modulus phakathi kwamabhulashi e-polymer ahlanganisiwe kanye ne-SiHy substrate, noma isakhiwo/ubuningi bamabhulashi e-polymer, noma inhlanganisela yawo. Kodwa-ke, kudingeka izifundo ezengeziwe ezijulile ukuze kuqondwe ngokugcwele ubudlelwano phakathi kwesakhiwo nezakhiwo, ikakhulukazi umphumela wokuhlanganiswa kwamabhulashi ezimpahleni zemishini. Ukulinganisa okufanayo kungasiza ekuchazeni izakhiwo zemishini zobuso bezinye izinto ezithambile kakhulu namadivayisi ezokwelapha.
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