Ua tsaug rau koj tuaj xyuas Nature.com.Koj siv lub browser version nrog kev txhawb nqa CSS tsawg.Rau qhov kev paub zoo tshaj plaws, peb xav kom koj siv qhov browser tshiab (lossis lov tes taw Compatibility Hom hauv Internet Explorer).Tsis tas li ntawd, txhawm rau xyuas kom muaj kev txhawb nqa tsis tu ncua, peb qhia lub vev xaib tsis muaj qauv thiab JavaScript.
Qhia ib lub carousel ntawm peb slides ib zaug.Siv cov nyees khawm dhau los thiab Tom ntej kom txav mus los ntawm peb qhov swb ib zaug, lossis siv cov khawm slider thaum kawg kom txav mus los ntawm peb qhov swb ib zaug.
Nrog rau kev txhim kho cov ntaub ntawv tshiab ultra-soft rau cov khoom siv kho mob thiab kev siv biomedical, cov yam ntxwv ntawm lawv lub cev thiab cov khoom siv kho tshuab yog qhov tseem ceeb thiab nyuaj.Ib qho kev hloov kho atomic force microscopy (AFM) nanoindentation txheej txheem tau siv los ua tus yam ntxwv ntawm qhov tsis tshua muaj deg modulus ntawm lehfilcon tshiab A biomimetic silicone hydrogel hu rau lo ntsiab muag coated nrog ib txheej ntawm branched polymer txhuam qauv.Txoj kev no tso cai rau kev txiav txim siab ntawm cov ntsiab lus sib cuag yam tsis muaj qhov cuam tshuam ntawm cov kua nplaum extrusion thaum mus txog cov ceg ntoo polymers.Tsis tas li ntawd, nws ua rau nws muaj peev xwm txiav txim siab cov yam ntxwv ntawm tus neeg txhuam hniav yam tsis muaj qhov cuam tshuam ntawm poroelasticity.Qhov no ua tiav los ntawm kev xaiv AFM sojntsuam nrog tus qauv tsim (qhov loj me, geometry thiab caij nplooj ntoos hlav tus nqi) uas yog tshwj xeeb tshaj yog haum rau kev ntsuas cov khoom ntawm cov khoom muag thiab cov qauv lom.Txoj kev no txhim kho rhiab heev thiab raug rau kev ntsuas qhov tseeb ntawm cov khoom muag heev lehfilcon A, uas muaj qhov tsis tshua muaj kev hloov pauv ntawm elasticity ntawm thaj chaw saum npoo av (txog 2 kPa) thiab cov elasticity siab heev hauv sab hauv (yuav luag 100%) aqueous ib puag ncig. .Cov txiaj ntsig ntawm kev tshawb fawb saum npoo tsis tsuas yog qhia tawm cov khoom ntawm lub ntsej muag ntawm lub ntsej muag ntawm lub lens lehfilcon A, tab sis kuj tau pom tias cov qauv ntawm cov txhuam hniav ntawm cov ceg ntoo tau muab piv rau cov silicon-hydrogen substrate.Cov txheej txheem deg tus cwj pwm no tuaj yeem siv rau lwm cov ntaub ntawv mos mos thiab cov khoom siv kho mob.
Cov khoom siv ntawm cov khoom tsim los rau kev sib cuag ncaj qha nrog cov ntaub so ntswg nyob feem ntau txiav txim siab los ntawm ib puag ncig lom neeg.Qhov kev sib tw zoo tshaj plaws ntawm cov khoom siv no pab ua kom tiav cov yam ntxwv kho mob xav tau ntawm cov khoom tsis ua rau cov lus teb tsis zoo ntawm tes 1,2,3.Rau cov ntaub ntawv homogeneous ntau, tus yam ntxwv ntawm cov khoom siv kho tshuab yog qhov yooj yim vim muaj cov txheej txheem txheej txheem thiab cov txheej txheem xeem (xws li microindentation4,5,6).Txawm li cas los xij, rau cov ntaub ntawv mos mos xws li gels, hydrogels, biopolymers, cov hlwb muaj sia, thiab lwm yam, cov kev sim no feem ntau tsis siv tau vim kev ntsuas kev daws teeb meem thiab qhov tsis sib xws ntawm qee cov ntaub ntawv7.Tau ntau xyoo, cov txheej txheem indentation ib txwm tau hloov kho thiab hloov kho kom haum rau ntau yam ntawm cov ntaub ntawv mos, tab sis ntau txoj hauv kev tseem raug kev txom nyem los ntawm qhov tsis zoo uas txwv tsis pub siv 8,9,10,11,12,13.Qhov tsis muaj cov kev sim tshwj xeeb uas tuaj yeem ua kom raug thiab ntseeg tau tus yam ntxwv ntawm cov khoom siv hluav taws xob ntawm cov khoom siv supersoft thiab cov txheej txheem saum npoo hnyav txwv tsis pub siv ntau yam kev siv.
Hauv peb txoj haujlwm yav dhau los, peb tau qhia txog lehfilcon A (CL) hu rau lub lens, cov khoom siv mos heterogeneous nrog tag nrho cov khoom muag ntawm lub ntsej muag uas tau txais los ntawm cov qauv tsim biomimetic tshwm sim los ntawm qhov chaw ntawm lub qhov muag ntawm lub qhov muag.Cov khoom siv biomaterial no tau tsim los ntawm grafting ib ceg, hla-txuas polymer txheej ntawm poly (2-methacryloyloxyethylphosphorylcholine (MPC)) (PMPC) mus rau silicone hydrogel (SiHy) 15 tsim rau cov khoom siv kho mob raws li.Cov txheej txheem grafting no tsim ib txheej ntawm qhov chaw uas muaj ib tug heev mos thiab elastic branched polymeric txhuam qauv.Peb cov haujlwm yav dhau los tau lees paub tias cov qauv biomimetic ntawm lehfilcon A CL muab cov khoom zoo tshaj plaws xws li kev txhim kho wetting thiab fouling tiv thaiv, nce lubricity, thiab txo cov cell thiab kab mob adhesion15,16.Tsis tas li ntawd, kev siv thiab kev loj hlob ntawm cov khoom siv biomimetic no kuj qhia txog kev nthuav dav ntxiv rau lwm yam khoom siv biomedical.Yog li ntawd, nws yog ib qho tseem ceeb uas yuav tsum tau ua tus yam ntxwv ntawm cov khoom saum npoo ntawm cov khoom siv ultra-soft no thiab nkag siab txog nws cov kev sib cuam tshuam nrog lub qhov muag txhawm rau tsim kom muaj kev paub dav dav los txhawb kev txhim kho thiab kev siv yav tom ntej.Feem ntau cov khoom lag luam muaj SiHy cov lo ntsiab muag yog tsim los ntawm homogeneous sib xyaw ntawm hydrophilic thiab hydrophobic polymers uas tsim cov khoom siv sib xws17.Ntau qhov kev tshawb fawb tau ua los tshawb xyuas lawv cov khoom siv kho tshuab siv cov tsoos compression, tensile thiab microindentation test method18,19,20,21.Txawm li cas los xij, cov qauv biomimetic tshiab ntawm lehfilcon A CL ua rau nws muaj cov khoom siv sib txawv tshwj xeeb uas cov khoom siv ntawm cov ceg ntoo polymer txhuam cov qauv sib txawv ntawm cov SiHy puag substrate.Yog li ntawd, nws yog ib qho nyuaj heev kom muaj tseeb kom muaj nuj nqis ntawm cov khoom siv cov pa thiab indentation txoj kev.Ib txoj hauv kev zoo siv txoj kev ntsuas nanoindentation siv hauv atomic force microscopy (AFM), ib txoj hauv kev uas tau siv los txiav txim siab cov khoom ntawm cov khoom siv mos viscoelastic xws li cov hlwb thiab cov ntaub so ntswg, nrog rau cov mos mos polymers22,23,24,25. .26, 27, 28, 29, 30 ib.Hauv AFM nanoindentation, lub hauv paus ntawm kev sim nanoindentation yog ua ke nrog cov kev nce qib tshiab hauv AFM thev naus laus zis los muab kev ntsuas kev ntsuas siab thiab ntsuas ntau yam ntawm cov khoom siv supersoft 31,32,33,34,35,36.Tsis tas li ntawd, thev naus laus zis muaj lwm yam tseem ceeb los ntawm kev siv cov geometry sib txawv.indenter thiab sojntsuam thiab muaj peev xwm ntawm kev sim nyob rau hauv ntau yam kua xov xwm.
AFM nanoindentation tuaj yeem muab faib ua peb yam tseem ceeb: (1) cov khoom siv (sensors, detectors, probes, etc.);(2) ntsuas qhov ntsuas (xws li quab yuam, hloov chaw, nrawm, qhov loj me, thiab lwm yam);(3) Kev ua cov ntaub ntawv (kev kho lub hauv paus, kev ntsuas qhov taw tes, cov ntaub ntawv haum, qauv, thiab lwm yam).Ib qho teeb meem tseem ceeb ntawm txoj kev no yog tias ntau qhov kev tshawb fawb hauv cov ntaub ntawv siv AFM nanoindentation qhia txog ntau qhov sib txawv rau tib cov qauv / cell / cov ntaub ntawv hom 37,38,39,40,41.Piv txwv li, Lekka et al.Kev cuam tshuam ntawm AFM sojntsuam geometry ntawm qhov ntsuas Young's modulus ntawm cov qauv ntawm cov tshuab ua homogeneous hydrogel thiab heterogeneous hlwb tau kawm thiab muab piv.Lawv tshaj tawm tias cov nqi modulus yog nyob ntawm qhov kev xaiv cantilever thiab cov duab zoo, nrog tus nqi siab tshaj plaws rau kev sojntsuam zoo li pyramid thiab tus nqi qis tshaj ntawm 42 rau kev sojntsuam spherical.Ib yam li ntawd, Selhuber-Unkel et al.Nws tau pom tias yuav ua li cas qhov indenter ceev, indenter loj thiab tuab ntawm polyacrylamide (PAAM) cov qauv cuam tshuam rau Young's modulus ntsuas los ntawm ACM43 nanoindentation.Lwm qhov teeb meem yog qhov tsis muaj cov txheej txheem tsis tshua muaj cov khoom siv ntsuas ntsuas thiab cov txheej txheem kuaj dawb.Qhov no ua rau nws nyuaj heev kom tau txais cov txiaj ntsig raug nrog kev ntseeg siab.Txawm li cas los xij, txoj kev no muaj txiaj ntsig zoo rau kev ntsuas txheeb ze thiab kev sib piv ntawm cov qauv zoo sib xws, piv txwv li siv AFM nanoindentation kom paub qhov txawv ntawm cov hlwb ntawm cov qog nqaij hlav cancer 44, 45.
Thaum kuaj cov ntaub ntawv mos nrog AFM nanoindentation, txoj cai dav dav ntawm tus ntiv tes xoo yog siv cov kev sojntsuam nrog lub caij nplooj ntoos hlav qis tsis tu ncua (k) uas zoo sib xws rau cov qauv qauv thiab ib qho hemispherical / round tip kom thawj qhov kev sojntsuam tsis tho cov qauv ntawm qhov chaw. thawj kev sib cuag nrog cov ntaub ntawv mos.Nws tseem yog ib qho tseem ceeb uas lub teeb liab deflection generated los ntawm kev sojntsuam yuav tsum muaj zog txaus kom pom los ntawm lub laser detector system24,34,46,47.Nyob rau hauv cov ntaub ntawv ntawm ultra-soft heterogeneous hlwb, cov ntaub so ntswg thiab gels, lwm qhov kev sib tw yog kom kov yeej cov nplaum quab yuam ntawm qhov kev sojntsuam thiab cov qauv saum npoo kom ntseeg tau tias cov khoom tsim tau thiab txhim khu kev qha 48,49,50.Txog thaum tsis ntev los no, feem ntau ua haujlwm ntawm AFM nanoindentation tau tsom mus rau kev kawm txog kev coj tus cwj pwm ntawm cov kabmob lom neeg, cov ntaub so ntswg, gels, hydrogels, thiab biomolecules siv cov kabmob loj loj, feem ntau hu ua colloidal probes (CPs)., 47, 51, 52, 53, 54, 55. Cov lus qhia no muaj lub vojvoog ntawm 1 txog 50 µm thiab feem ntau yog tsim los ntawm borosilicate iav, polymethyl methacrylate (PMMA), polystyrene (PS), silicon dioxide (SiO2) thiab pob zeb diamond- zoo li carbon (DLC).Txawm hais tias CP-AFM nanoindentation feem ntau yog thawj qhov kev xaiv rau cov qauv muag muag, nws muaj nws cov teeb meem thiab kev txwv.Kev siv cov lus qhia loj, micron-loj spherical tsub kom tag nrho qhov chaw sib cuag ntawm lub taub nrog cov qauv thiab ua rau muaj kev cuam tshuam loj ntawm kev daws teeb meem spatial.Rau cov mos mos, inhomogeneous specimens, qhov twg cov khoom siv ntawm cov khoom hauv zos yuav txawv ntawm qhov nruab nrab ntawm qhov dav dav, CP indentation tuaj yeem nkaum qhov tsis sib xws hauv cov khoom ntawm lub zos scale52.Colloidal probes feem ntau yog ua los ntawm kev txuas micron-loj colloidal spheres rau tipless cantilevers siv epoxy adhesives.Cov txheej txheem tsim khoom nws tus kheej yog fraught nrog ntau yam teeb meem thiab tuaj yeem ua rau tsis sib xws hauv cov txheej txheem sojntsuam calibration.Tsis tas li ntawd, qhov loj thiab qhov loj ntawm colloidal hais ncaj qha cuam tshuam rau lub ntsiab calibration ntawm lub cantilever, xws li resonant zaus, lub caij nplooj ntoos hlav tawv, thiab deflection rhiab heev 56,57,58.Yog li, feem ntau siv cov txheej txheem rau cov pa AFM probes, xws li ntsuas kub, yuav tsis muab qhov tseeb calibration rau CP, thiab lwm txoj kev yuav tsum tau ua cov kev kho no 57, 59, 60, 61. Hom CP indentation thwmsim siv loj deviations cantilever rau. kawm cov khoom ntawm cov qauv mos, uas tsim lwm qhov teeb meem thaum ntsuas tus cwj pwm tsis-linear ntawm cantilever ntawm qhov sib txawv loj heev62,63,64.Niaj hnub nimno colloidal sojntsuam indentation txoj kev feem ntau coj mus rau hauv tus account lub geometry ntawm lub cantilever siv los calibrate lub sojntsuam, tab sis tsis quav ntsej lub zog ntawm colloidal hais, uas ua rau ntxiv uncertainty nyob rau hauv qhov tseeb ntawm txoj kev38,61.Ib yam li ntawd, elastic moduli xam los ntawm kev sib cuag qauv haum yog ncaj qha nyob ntawm lub geometry ntawm indentation sojntsuam, thiab mismatch ntawm cov lus qhia thiab cov qauv saum npoo yuav ua rau inaccuracies27, 65, 66, 67, 68. Qee qhov haujlwm tsis ntev los no los ntawm Spencer li al.Cov yam tseem ceeb uas yuav tsum tau coj mus rau hauv tus account thaum ua tus cwj pwm mos mos txhuam hniav siv CP-AFM nanoindentation txoj kev yog qhia.Lawv tau tshaj tawm tias qhov khaws cia ntawm cov kua dej khov hauv cov txhuam hniav polymer ua haujlwm ntawm qhov nrawm ua rau muaj kev nce hauv lub taub hau thiab yog li kev ntsuas sib txawv ntawm cov khoom siv ceev ceev 30,69,70,71.
Hauv txoj kev tshawb no, peb tau pom cov qauv saum npoo ntawm cov khoom siv ultra-mos elastic heev lehfilcon A CL siv txoj kev hloov kho AFM nanoindentation.Muab cov khoom thiab cov qauv tshiab ntawm cov khoom siv no, qhov rhiab heev ntawm cov txheej txheem indentation yog qhov tsis txaus rau tus yam ntxwv ntawm cov khoom siv mos mos, yog li nws yuav tsum siv txoj kev AFM nanoindentation nrog ntau dua rhiab heev thiab qis rhiab heev.qib.Tom qab tshuaj xyuas qhov tsis txaus thiab cov teeb meem ntawm cov txheej txheem colloidal AFM nanoindentation uas twb muaj lawm, peb qhia tias yog vim li cas peb thiaj xaiv qhov me me, kev cai tsim AFM sojntsuam kom tshem tawm rhiab heev, suab nrov tom qab, pinpoint point ntawm kev sib cuag, ntsuas qhov nrawm modulus ntawm cov ntaub ntawv mos heterogeneous xws li dej tuav. kev vam khom.thiab kom muaj nuj nqis.Tsis tas li ntawd, peb muaj peev xwm ntsuas qhov zoo thiab qhov ntev ntawm cov lus qhia indentation, tso cai rau peb siv lub cone-sphere haum qauv los txiav txim lub modulus ntawm elasticity yam tsis tau ntsuas qhov chaw sib cuag ntawm lub taub nrog cov khoom.Ob qhov kev xav tsis zoo uas suav nrog hauv txoj haujlwm no yog cov khoom siv elastic tag nrho thiab qhov kev nkag siab tob-yooj yim modulus.Siv cov qauv no, peb thawj zaug sim cov qauv ultra-soft nrog cov qauv paub los ntsuas cov qauv, thiab tom qab ntawd siv cov qauv no los qhia qhov chaw ntawm ob qhov sib txawv ntawm cov khoom siv lens.Txoj kev no ntawm tus cwj pwm AFM nanoindentation nto nrog nce rhiab heev yuav tsum muaj feem xyuam rau ntau yam biomimetic heterogeneous ultrasoft cov ntaub ntawv uas muaj peev xwm siv tau rau hauv cov khoom siv kho mob thiab kev siv biomedical.
Lehfilcon A contact lenses (Alcon, Fort Worth, Texas, USA) thiab lawv cov silicone hydrogel substrates raug xaiv rau kev sim nanoindentation.Ib qho tshwj xeeb tsim lens mount tau siv hauv kev sim.Txhawm rau nruab lub lens rau kev sim, nws tau ua tib zoo muab tso rau ntawm lub dome-shaped sawv ntsug, ua kom tsis muaj cua npuas nkag mus rau hauv, thiab tom qab ntawd kho nrog cov npoo.Ib lub qhov nyob rau hauv lub fixture nyob rau sab saum toj ntawm lub lens tuav muab kev nkag mus rau qhov chaw kho qhov muag ntawm lub lens rau kev sim nanoindentation thaum tuav cov kua hauv qhov chaw.Qhov no ua rau cov lo ntsiab muag muaj dej txaus.500 μl ntawm kev tiv thaiv lub lens ntim tshuaj tau siv los ua cov tshuaj ntsuam xyuas.Txhawm rau txheeb xyuas cov txiaj ntsig ntau, cov khoom lag luam uas tsis yog siv cov polyacrylamide (PAAM) hydrogels tau npaj los ntawm polyacrylamide-co-methylene-bisacrylamide muaj pes tsawg leeg (100 hli Petrisoft Petri tais diav, Matrigen, Irvine, CA, USA), paub txog elastic modulus ntawm 1 kPa ua.Siv 4-5 tee (kwv yees li 125 µl) ntawm phosphate buffered saline (PBS los ntawm Corning Life Sciences, Tewkesbury, MA, USA) thiab 1 poob ntawm OPTI-FREE Puremoist contact lens solution (Alcon, Vaud, TX, USA).) ntawm AFM hydrogel-probe interface.
Cov qauv ntawm Lehfilcon A CL thiab SiHy substrates tau pom pom siv FEI Quanta 250 Field Emission Scanning Electron Microscope (FEG SEM) system nruab nrog Scanning Transmission Electron Microscope (STEM) detector.Txhawm rau npaj cov qauv, cov lo ntsiab muag yog thawj zaug ntxuav nrog dej thiab txiav rau hauv lub ncuav mog qab zib.Txhawm rau ua tiav qhov sib txawv ntawm qhov sib txawv ntawm hydrophilic thiab hydrophobic Cheebtsam ntawm cov qauv, 0.10% stabilized tov ntawm RuO4 tau siv los ua cov xim, uas cov qauv tau muab tso rau hauv 30 min.Lub lehfilcon A CL RuO4 staining yog ib qho tseem ceeb tsis yog tsuas yog ua kom muaj kev sib txawv ntawm qhov sib txawv, tab sis kuj tseem pab khaws cov qauv ntawm cov txhuam hniav polymer hauv lawv daim ntawv qub, uas tom qab ntawd pom ntawm STEM cov duab.Tom qab ntawd lawv tau ntxuav thiab dehydrated nyob rau hauv ib tug series ntawm ethanol / dej sib tov nrog nce ethanol concentration.Cov qauv no tau muab pov tseg nrog EMBed 812 / Araldite epoxy, uas kho thaum hmo ntuj ntawm 70 ° C.Cov qauv blocks tau los ntawm resin polymerization raug txiav nrog ib qho ultramicrotome, thiab cov seem nyias nyias tau pom nrog lub STEM detector nyob rau hauv qis lub tshuab nqus tsev vacuum ntawm ib tug accelerating voltage ntawm 30 kV.Tib SEM system tau siv rau cov ncauj lus ntxaws ntxaws ntawm PFQNM-LC-A-CAL AFM sojntsuam (Bruker Nano, Santa Barbara, CA, USA).SEM dluab ntawm AFM sojntsuam tau txais nyob rau hauv ib tug raug high lub tshuab nqus tsev hom nrog ib tug accelerating voltage ntawm 30 kV.Tau txais cov duab ntawm qhov sib txawv thiab qhov loj me los sau tag nrho cov ntsiab lus ntawm cov duab thiab qhov loj ntawm AFM sojntsuam taub.Tag nrho cov lus qhia qhov ntev ntawm kev txaus siab hauv cov duab tau ntsuas digitally.
Lub Dimension FastScan Bio Icon atomic force microscope (Bruker Nano, Santa Barbara, CA, USA) nrog "PeakForce QNM hauv Fluid" hom tau siv los pom thiab nanoindentate lehfilcon A CL, SiHy substrate, thiab PAAm hydrogel kuaj.Rau kev sim duab, PEAKFORCE-HIRS-FA kev sojntsuam (Bruker) nrog lub npe ntawm lub vojvoog ntawm 1 nm tau siv los ntes cov duab daws teeb meem ntawm tus qauv ntawm tus lej scan ntawm 0.50 Hz.Tag nrho cov duab tau muab coj los rau hauv cov tshuaj aqueous.
AFM nanoindentation thwmsim tau ua tiav siv PFQNM-LC-A-CAL sojntsuam (Bruker).Lub AFM sojntsuam muaj ib tug silicon taub ntawm ib tug nitride cantilever 345 nm tuab, 54 µm ntev thiab 4.5 µm dav nrog ib tug resonant zaus ntawm 45 kHz.Nws yog tsim tshwj xeeb los ua tus yam ntxwv thiab ua kom muaj nuj nqis nanomechanical ntsuas ntawm cov qauv tshuaj lom neeg.Cov sensors yog tus kheej calibrated ntawm lub Hoobkas nrog pre-calibrated caij nplooj ntoos hlav.Lub caij nplooj ntoos hlav tsis tu ncua ntawm kev sojntsuam siv hauv txoj kev tshawb no yog nyob rau hauv thaj tsam ntawm 0.05–0.1 N / m.Txhawm rau txiav txim siab qhov zoo thiab qhov loj ntawm lub taub, qhov kev sojntsuam tau qhia meej meej siv SEM.Ntawm daim duab.Daim duab 1a qhia tau hais tias muaj kev daws teeb meem siab, tsis tshua muaj qhov loj me scanning electron micrograph ntawm PFQNM-LC-A-CAL kev sojntsuam, muab kev pom zoo ntawm kev sojntsuam tsim.Ntawm daim duab.1b qhia pom qhov loj ntawm sab saum toj ntawm qhov kev sojntsuam, muab cov ntaub ntawv hais txog cov duab thiab qhov loj ntawm lub taub.Thaum kawg, rab koob yog hemisphere txog 140 nm inch (Fig. 1c).Hauv qab no, lub taub tapers rau hauv cov duab conical, ncav cuag qhov ntev ntawm kwv yees li 500 nm.Sab nraum lub cheeb tsam tapering, lub taub yog cylindrical thiab xaus nyob rau hauv tag nrho cov lus qhia ntev ntawm 1.18 µm.Qhov no yog lub luag haujlwm tseem ceeb ntawm kev sojntsuam taub.Tsis tas li ntawd, ib qho loj spherical polystyrene (PS) sojntsuam (Novascan Technologies, Inc., Boone, Iowa, USA) nrog lub taub hau ntawm 45 µm thiab lub caij nplooj ntoos hlav tsis tu ncua ntawm 2 N / m kuj tau siv los kuaj raws li kev sojntsuam colloidal.nrog PFQNM-LC-A-CAL 140 nm sojntsuam rau kev sib piv.
Nws tau raug tshaj tawm tias cov kua tuaj yeem raug daig ntawm AFM kev sojntsuam thiab cov qauv txhuam polymer thaum lub sijhawm nanoindentation, uas yuav ua rau lub zog nce siab ntawm AFM kev sojntsuam ua ntej nws yeej kov lub ntsej muag69.Qhov no viscous extrusion nyhuv vim cov kua tuav tau tuaj yeem hloov qhov pom tseeb ntawm kev sib cuag, yog li cuam tshuam rau qhov ntsuas qhov ntsuas ntawm qhov ntsuas.Txhawm rau kawm txog cov txiaj ntsig ntawm kev sojntsuam geometry thiab indentation ceev ntawm cov kua tuav, indentation force curves tau npaj rau lehfilcon A CL cov qauv siv 140 nm txoj kab uas hla ntawm kev txav mus tas li ntawm 1 µm / s thiab 2 µm / s.sojntsuam txoj kab uas hla 45 µm, tsau quab yuam 6 nN tiav ntawm 1 µm / s.Kev sim nrog kev sojntsuam 140 nm hauv txoj kab uas hla tau ua tiav ntawm qhov nrawm nrawm ntawm 1 µm / s thiab lub zog ntawm 300 pN, xaiv los tsim kom muaj kev sib cuag hauv lub cev (1-8 kPa) ntawm daim tawv muag sab saud.siab 72. Mos npaj-ua qauv ntawm PAA hydrogel nrog lub siab ntawm 1 kPa tau sim rau lub indentation quab yuam ntawm 50 pN ntawm ib tug ceev ntawm 1 μm / s siv ib tug sojntsuam nrog ib txoj kab uas hla ntawm 140 nm.
Txij li qhov ntev ntawm qhov conical ib feem ntawm lub ntsis ntawm PFQNM-LC-A-CAL sojntsuam yog kwv yees li 500 nm, rau ib qho indentation qhov tob < 500 nm nws tuaj yeem muaj kev nyab xeeb xav tias geometry ntawm kev sojntsuam thaum lub sijhawm indentation yuav nyob twj ywm rau nws. lub khob hliav qab.Tsis tas li ntawd, nws tau xav tias qhov saum npoo ntawm cov khoom nyob rau hauv kev sim yuav nthuav tawm cov lus teb rov qab elastic, uas tseem yuav raug lees paub hauv cov lus hauv qab no.Yog li ntawd, nyob ntawm cov duab thiab qhov loj ntawm lub taub, peb xaiv lub khob-sphere haum qauv tsim los ntawm Briscoe, Sebastian thiab Adams, uas muaj nyob rau hauv tus neeg muag khoom software, los ua peb cov kev sim AFM nanoindentation (NanoScope).Sib cais cov ntaub ntawv txheeb xyuas software, Bruker) 73. Tus qauv piav qhia txog kev sib raug zoo ntawm kev quab yuam F(δ) rau lub khob hliav qab uas muaj lub ntsej muag kheej kheej.Ntawm daim duab.Daim duab 2 qhia txog kev sib cuag geometry thaum lub sij hawm sib cuam tshuam ntawm lub khob hliav qab nrog lub hau kheej kheej, qhov twg R yog lub vojvoog ntawm lub taub hau kheej kheej, a yog lub vojvoog sib cuag, b yog lub vojvoog sib cuag ntawm qhov kawg ntawm tus kheej kheej, δ yog tiv tauj vojvoog.indentation tob, θ yog ib nrab-lub kaum sab xis ntawm lub khob hliav qab.Daim duab SEM ntawm qhov kev sojntsuam no qhia meej tias 140 nm txoj kab uas hla spherical taub sib koom ua ke tangentially rau hauv lub khob hliav qab, yog li ntawm no b yog txhais los ntawm R, piv txwv li b = R cos θ.Tus neeg muag khoom-muab software muab lub khob-sphere kev sib raug zoo los xam Young's modulus (E) qhov tseem ceeb los ntawm kev sib cais cov ntaub ntawv piv txwv li a> b.Kev sib raug zoo:
qhov twg F yog lub zog indentation, E yog Young's modulus, ν yog Poisson tus piv.Kev sib cuag vojvoog a tuaj yeem kwv yees siv:
Cov txheej txheem ntawm kev sib cuag geometry ntawm lub khob hliav qab nruj nrog lub hau kheej kheej nias rau hauv cov khoom ntawm Lefilcon contact lens nrog rau txheej txheej ntawm cov ceg tawv polymer txhuam.
Yog hais tias ib tug ≤ b, qhov kev sib raug zoo txo ​​mus rau qhov sib npaug rau ib tug pa kheej kheej indenter;
Peb ntseeg hais tias kev sib cuam tshuam ntawm qhov kev sojntsuam indenting nrog cov qauv ceg ntawm PMPC polymer txhuam yuav ua rau lub vojvoog sib cuag a kom ntau dua li lub voj voos kheej kheej b.Yog li ntawd, rau tag nrho cov kev ntsuas ntau ntawm cov elastic modulus ua nyob rau hauv txoj kev tshawb no, peb siv qhov dependence tau rau rooj plaub a> b.
Cov ntaub ntawv ultrasoft biomimetic kawm nyob rau hauv txoj kev tshawb no tau pom zoo siv scanning kis electron microscopy (STEM) ntawm tus qauv hla ntu thiab atomic force microscopy (AFM) ntawm qhov chaw.Cov ncauj lus kom ntxaws saum npoo no tau ua tiav raws li kev txuas ntxiv ntawm peb cov haujlwm yav dhau los luam tawm, uas peb tau txiav txim siab tias cov qauv ntawm lub ntsej muag dynamically branched polymeric txhuam ntawm PMPC-hloov lehfilcon A CL nto nthuav tawm cov khoom zoo sib xws rau cov nqaij pob txha 14.Vim li no, peb xa mus rau qhov chaw ntawm lub lens raws li cov ntaub ntawv biomimetic14.Ntawm daim duab.3a, b qhia hla ntu ntawm branched PMPC polymer txhuam cov qauv ntawm qhov chaw ntawm lehfilcon A CL substrate thiab ib qho tsis kho SiHy substrate, feem.Qhov chaw ntawm ob qho tib si kuaj tau raug tshuaj xyuas ntxiv siv cov duab AFM siab, uas tau lees paub ntxiv cov txiaj ntsig ntawm STEM tsom xam (Fig. 3c, d).Muab ua ke, cov duab no muab qhov kwv yees ntev ntawm PMPC branched polymer txhuam qauv ntawm 300-400 nm, uas yog ib qho tseem ceeb rau kev txhais AFM nanoindentation ntsuas.Lwm qhov kev soj ntsuam tseem ceeb tau muab los ntawm cov duab yog tias tag nrho cov qauv saum npoo ntawm CL biomimetic cov khoom yog morphologically txawv ntawm cov khoom siv SiHy substrate.Qhov sib txawv no hauv lawv qhov chaw morphology tuaj yeem pom meej thaum lawv cov kev sib cuam tshuam nrog cov indenting AFM sojntsuam thiab tom qab ntawd hauv qhov ntsuas qhov ntsuas.
Hla-sectional STEM duab ntawm (a) lehfilcon A CL thiab (b) SiHy substrate.Scale bar, 500nm.AFM cov duab ntawm qhov chaw ntawm lehfilcon A CL substrate (c) thiab lub hauv paus SiHy substrate (d) (3 µm × 3 µm).
Bioinspired polymers thiab polymer txhuam cov qauv yog inherently mos thiab tau dav kawm thiab siv nyob rau hauv ntau yam biomedical applications74,75,76,77.Yog li ntawd, nws yog ib qho tseem ceeb uas yuav tsum tau siv AFM nanoindentation txoj kev, uas tuaj yeem ntsuas qhov tseeb thiab ntseeg tau lawv cov khoom siv tshuab.Tab sis nyob rau tib lub sijhawm, cov khoom tshwj xeeb ntawm cov khoom siv ultra-soft, xws li tsis tshua muaj elastic modulus, cov ntsiab lus ua kua thiab siab elasticity, feem ntau ua rau nws nyuaj rau xaiv cov khoom tsim nyog, cov duab thiab cov duab ntawm indenting sojntsuam.qhov loj.Qhov no yog ib qho tseem ceeb kom lub indenter tsis chob lub mos nto ntawm tus qauv, uas yuav ua rau kom tsis ncaj ncees lawm kev txiav txim ntawm qhov chaw ntawm kev sib cuag nrog cov nto thiab qhov chaw ntawm kev sib cuag.
Rau qhov no, kev nkag siab zoo ntawm morphology ntawm ultra-soft biomimetic cov ntaub ntawv (lehfilcon A CL) yog qhov tseem ceeb.Cov ntaub ntawv hais txog qhov loj thiab cov qauv ntawm cov txhuam hniav polymer uas tau txais los ntawm kev siv cov duab thaij duab muab lub hauv paus rau cov neeg kho tshuab cov yam ntxwv ntawm qhov chaw siv AFM nanoindentation cov tswv yim.Hloov chaw micron-loj spherical colloidal sojntsuam, peb xaiv PFQNM-LC-A-CAL silicon nitride sojntsuam (Bruker) nrog lub taub hau ntawm 140 nm, tshwj xeeb uas tsim los rau ntau daim ntawv qhia txog cov khoom siv ntawm cov khoom siv roj ntsha 78, 79, 80 , 81, 82, 83, 84 Qhov laj thawj rau kev siv cov kev sojntsuam ntse zoo piv rau cov khoom siv sib xyaw ua ke tuaj yeem piav qhia los ntawm cov yam ntxwv ntawm cov khoom siv.Muab piv rau qhov kev sojntsuam qhov loj me (~140 nm) nrog cov txhuam hniav polymer rau ntawm qhov chaw ntawm CL lehfilcon A, qhia hauv daim duab 3a, nws tuaj yeem txiav txim siab tias qhov ntxeev yog qhov loj txaus los rau hauv kev sib cuag ncaj qha nrog cov txhuam hniav, uas. txo lub sij hawm ntawm lub ntsis tho los ntawm lawv.Txhawm rau qhia txog qhov no, hauv daim duab 4 yog ib daim duab STEM ntawm lehfilcon A CL thiab lub ntsiab lus ntawm AFM sojntsuam (kos rau qhov ntsuas).
Schematic qhia STEM duab ntawm lehfilcon A CL thiab ACM indentation sojntsuam (kos rau nplai).
Tsis tas li ntawd, cov lus qhia me me ntawm 140 nm yog qhov me me kom tsis txhob muaj kev pheej hmoo ntawm ib qho ntawm cov nplaum nplaum extrusion yav dhau los tau tshaj tawm rau cov txhuam hniav polymer uas tsim los ntawm CP-AFM nanoindentation method69,71.Peb xav tias vim qhov tshwj xeeb cone-spherical zoo thiab kuj me me ntawm qhov AFM ntsis (Fig. 1), qhov xwm ntawm lub zog nkhaus generated los ntawm lehfilcon A CL nanoindentation yuav tsis nyob ntawm qhov indentation ceev los yog lub loading / unloading ceev. .Yog li ntawd, nws tsis cuam tshuam los ntawm cov teebmeem poroelastic.Txhawm rau ntsuas qhov kev xav no, lehfilcon A CL cov qauv tau muab tso rau ntawm lub zog siab tshaj plaws uas siv PFQNM-LC-A-CAL kev sojntsuam, tab sis ntawm ob qhov sib txawv, thiab qhov tshwm sim tensile thiab retract force curves tau siv los npaj lub zog (nN) hauv kev sib cais (µm) yog qhia hauv daim duab 5a.Nws yog qhov tseeb tias lub zog nkhaus thaum thauj khoom thiab tshem tawm tag nrho sib tshooj, thiab tsis muaj pov thawj tseeb tias lub zog shear ntawm xoom indentation qhov tob nce nrog indentation ceev hauv daim duab, qhia tias tus txhuam txhuam cov ntsiab lus tsis muaj cov nyhuv poroelastic.Nyob rau hauv sib piv, cov kua dej tuav cov teebmeem (viscous extrusion thiab poroelasticity teebmeem) yog pov thawj rau 45 µm txoj kab uas hla AFM sojntsuam ntawm tib lub indentation ceev thiab yog highlighted los ntawm lub hysteresis ntawm lub stretch thiab retract curves, raws li qhia nyob rau hauv daim duab 5b.Cov txiaj ntsig no txhawb qhov kev xav thiab qhia tias 140 nm txoj kab uas hla kev sojntsuam yog qhov kev xaiv zoo rau kev ua tus yam ntxwv zoo li no.
lehfilcon A CL indentation force curves siv ACM;(a) siv cov kev sojntsuam nrog ib txoj kab uas hla ntawm 140 nm ntawm ob qhov kev thauj khoom, ua kom pom qhov tsis muaj cov nyhuv poroelastic thaum lub sij hawm deg indentation;(b) siv probes nrog ib txoj kab uas hla ntawm 45 µm thiab 140 nm.s qhia cov teebmeem ntawm viscous extrusion thiab poroelasticity rau loj probes piv rau cov me me probes.
Txhawm rau ua tus yam ntxwv ntawm lub ntsej muag ultrasoft, AFM nanoindentation txoj kev yuav tsum muaj qhov kev sojntsuam zoo tshaj plaws los kawm txog cov khoom ntawm cov khoom hauv kev kawm.Ntxiv nrog rau lub ntsej muag thiab qhov loj me, qhov rhiab heev ntawm AFM ntes qhov system, rhiab heev rau lub ntsej muag deflection hauv qhov chaw sim, thiab cantilever txhav ua lub luag haujlwm tseem ceeb hauv kev txiav txim siab qhov tseeb thiab kev ntseeg siab ntawm nanoindentation.kev ntsuas.Rau peb cov AFM system, Qhov Kev Ntsuas Qhov Ntsuas (PSD) txwv ntawm kev kuaj pom yog kwv yees li 0.5 mV thiab yog raws li lub caij nplooj ntoo hlav ua ntej ntsuas thiab ntsuas cov kua dej deflection rhiab heev ntawm PFQNM-LC-A-CAL kev sojntsuam, uas sib haum rau theoretical load rhiab heev.tsawg dua 0.1 pN.Yog li ntawd, txoj kev no tso cai rau kev ntsuas qhov tsawg kawg nkaus indentation quab yuam ≤ 0.1 pN yam tsis muaj lub suab nrov ntawm lub tog raj kheej.Txawm li cas los xij, nws yuav luag tsis yooj yim sua rau AFM qhov system kom txo cov suab nrov ntawm cov suab nrov rau qib no vim muaj cov yam ntxwv xws li kev vibration thiab dej dynamics.Cov xwm txheej no txwv tag nrho cov kev xav ntawm AFM nanoindentation txoj kev thiab tseem ua rau lub suab nrov tom qab ntawm kwv yees li ≤ 10 pN.Rau kev ua tus cwj pwm saum npoo, cov qauv lehfilcon A CL thiab SiHy substrate tau muab tso rau hauv cov khoom siv hydrated tag nrho siv 140 nm sojntsuam rau SEM tus cwj pwm, thiab qhov tshwm sim ntawm lub zog nkhaus yog superimposed ntawm quab yuam (pN) thiab siab.Cov phiaj xwm sib cais (µm) yog qhia hauv daim duab 6a.Piv rau SiHy lub hauv paus substrate, lehfilcon A CL quab yuam nkhaus kom meej meej qhia tau hais tias lub sijhawm hloov pauv pib ntawm qhov chaw ntawm kev sib cuag nrog lub forked polymer txhuam thiab xaus nrog kev hloov pauv ntawm txoj kab nqes kev sib cuag ntawm lub taub nrog cov khoom siv hauv qab.Qhov kev hloov pauv ntawm lub zog nkhaus no qhia txog tus cwj pwm elastic tiag tiag ntawm cov ceg ntoo polymer txhuam ntawm qhov chaw, raws li muaj pov thawj los ntawm kev sib zog nkhaus zoo tom qab qhov nro nkhaus thiab qhov sib piv ntawm cov khoom siv kho tshuab ntawm cov qauv txhuam thiab cov khoom loj SiHy.Thaum sib piv lefilcon.Kev sib cais ntawm qhov nruab nrab ntev ntawm ib ceg ntoo polymer txhuam nyob rau hauv STEM duab ntawm PCS (Fig. 3a) thiab nws lub zog nkhaus raws lub abscissa hauv daim duab 3a.6a qhia tau hais tias txoj kev muaj peev xwm txheeb xyuas qhov ntxeev thiab cov ceg ntoo ntawm cov polymer mus txog rau saum npoo.Kev sib cuag ntawm txhuam cov qauv.Tsis tas li ntawd, kaw sib tshooj ntawm lub zog nkhaus qhia tias tsis muaj cov kua dej tuav.Hauv qhov no, tsis muaj qhov adhesion ntawm rab koob thiab qhov chaw ntawm tus qauv.Qhov saum toj kawg nkaus ntawm lub zog nkhaus rau ob qhov qauv sib tshooj, qhia txog qhov zoo sib xws ntawm cov khoom siv hluav taws xob ntawm cov khoom siv substrate.
(a) AFM nanoindentation force curves rau lehfilcon A CL substrates thiab SiHy substrates, (b) quab yuam curves qhia kev sib cuag taw tes kwv yees siv lub suab nrov tom qab pib txoj kev.
Txhawm rau kawm cov ntsiab lus zoo dua ntawm lub zog nkhaus, qhov nro nkhaus ntawm lehfilcon A CL qauv yog rov ua dua hauv daim duab 6b nrog lub zog siab tshaj plaws ntawm 50 pN raws li y-axis.Daim duab no muab cov ntaub ntawv tseem ceeb txog lub suab nrov tom qab.Lub suab nrov yog nyob rau hauv qhov ntau ntawm ± 10 pN, uas yog siv los txiav txim siab qhov chaw sib cuag thiab xam qhov tob indentation.Raws li tau tshaj tawm hauv cov ntaub ntawv, kev txheeb xyuas cov ntsiab lus ntawm kev sib cuag yog qhov tseem ceeb rau kev ntsuam xyuas cov khoom zoo xws li modulus85.Ib txoj hauv kev uas suav nrog kev ua haujlwm tsis siv neeg ntawm cov ntaub ntawv nkhaus quab yuam tau pom tias muaj kev txhim kho ntawm cov ntaub ntawv haum thiab kev ntsuas ntau rau cov ntaub ntawv mos86.Hauv txoj haujlwm no, peb xaiv cov ntsiab lus ntawm kev sib cuag yog qhov yooj yim thiab lub hom phiaj, tab sis nws muaj nws cov kev txwv.Peb txoj kev saib xyuas kev txiav txim siab ntawm qhov kev sib cuag yuav ua rau me ntsis overestimated modulus qhov tseem ceeb rau me me indentation depths (< 100 nm).Kev siv cov algorithm-raws li touchpoint nrhiav tau thiab automated cov ntaub ntawv ua yuav ua tau ib tug txuas ntxiv ntawm txoj hauj lwm no nyob rau hauv lub neej yav tom ntej los txhim kho peb txoj kev.Yog li, rau lub suab nrov ntawm qhov nruab nrab ntawm qhov kev txiav txim ntawm ± 10 pN, peb txhais qhov chaw tiv tauj raws li thawj cov ntaub ntawv taw qhia ntawm x-axis hauv daim duab 6b nrog tus nqi ntawm ≥10 pN.Tom qab ntawd, raws li lub suab nrov pib ntawm 10 pN, ib txoj kab ntsug ntawm theem ntawm ~ 0.27 µm cim qhov taw qhia ntawm kev sib cuag nrog rau saum npoo, tom qab ntawd txoj kev nkhaus txuas ntxiv mus txog rau thaum lub substrate ua tau raws li qhov tob indentation ntawm ~ 270 nm.Interestingly, raws li qhov luaj li cas ntawm branched polymer txhuam nta (300-400 nm) ntsuas siv txoj kev imaging, qhov tob indentation ntawm CL lehfilcon Ib tug qauv pom siv lub suab nrov tom qab pib txoj kev yog hais txog 270 nm, uas yog heev ze rau. qhov ntsuas qhov loj me nrog STEM.Cov txiaj ntsig no tau lees paub ntxiv txog kev sib raug zoo thiab kev siv tau ntawm cov duab thiab qhov loj ntawm AFM sojntsuam taub rau indentation ntawm no heev mos thiab elastic branched polymer txhuam qauv.Cov ntaub ntawv no tseem muab cov ntaub ntawv pov thawj muaj zog los txhawb peb txoj hauv kev siv lub suab nrov tom qab los ua qhov pib rau pinpointing cov ntsiab lus sib cuag.Yog li, txhua qhov txiaj ntsig tau los ntawm kev ua lej ua lej thiab kev quab yuam nkhaus yuav tsum yog qhov tseeb.
Kev ntsuas ntau los ntawm AFM nanoindentation txoj kev yog nyob ntawm cov qauv lej siv rau kev xaiv cov ntaub ntawv thiab kev tshuaj xyuas tom qab.Yog li ntawd, nws yog ib qho tseem ceeb uas yuav tau xav txog txhua yam uas cuam tshuam nrog kev xaiv ntawm indenter, cov khoom siv thiab cov tshuab ntawm lawv cov kev sib cuam tshuam ua ntej xaiv ib qho qauv.Nyob rau hauv cov ntaub ntawv no, cov lus qhia geometry tau ua tib zoo siv SEM micrographs (Daim duab 1), thiab raws li cov txiaj ntsig tau, 140 nm txoj kab uas hla AFM nanoindenting sojntsuam nrog lub khob tawv tawv thiab cov duab kheej kheej kheej kheej yog qhov kev xaiv zoo rau kev coj tus cwj pwm lehfilcon A CL79. .Lwm qhov tseem ceeb uas yuav tsum tau ua tib zoo soj ntsuam yog qhov elasticity ntawm cov khoom siv polymer raug kuaj.Txawm hais tias thawj cov ntaub ntawv ntawm nanoindentation (Fig. 5a thiab 6a) qhia meej txog cov yam ntxwv ntawm kev sib tshooj ntawm qhov nro thiab compression nkhaus, piv txwv li, ua tiav elastic rov qab ntawm cov khoom, nws yog ib qho tseem ceeb heev kom paub meej tias qhov elasticity ntawm kev sib cuag. .Txog rau qhov kawg no, ob qho kev ua tiav tau ua tiav ntawm tib qhov chaw ntawm qhov chaw ntawm lehfilcon A CL qauv ntawm qhov indentation tus nqi ntawm 1 µm / s nyob rau hauv tag nrho hydration.Cov ntaub ntawv ntawm lub zog nkhaus yog qhia hauv daim duab.7 thiab, raws li qhov xav tau, kev nthuav dav thiab kev nthuav dav ntawm ob daim ntawv luam tawm yuav luag zoo ib yam, qhia txog qhov siab elasticity ntawm cov ceg ntoo ntawm cov khoom siv polymer txhuam.
Ob qhov kev quab yuam nkhaus ntawm tib qhov chaw ntawm qhov chaw ntawm lehfilcon A CL qhia qhov zoo tshaj plaws elasticity ntawm lub lens nto.
Raws li cov ntaub ntawv tau txais los ntawm SEM thiab STEM dluab ntawm kev sojntsuam taub thiab lehfilcon A CL nto, feem, tus qauv cone-sphere yog ib tug tsim nyog lej sawv cev ntawm kev sib cuam tshuam ntawm AFM sojntsuam taub thiab cov ntaub ntawv mos polymer raug kuaj.Tsis tas li ntawd, rau cov qauv no cone-sphere, cov kev xav tseem ceeb ntawm cov khoom elastic ntawm cov khoom siv imprinted muaj tseeb rau cov khoom siv biomimetic tshiab no thiab siv los ntsuas qhov elastic modulus.
Tom qab kev soj ntsuam tag nrho ntawm AFM nanoindentation txoj kev thiab nws cov khoom, suav nrog cov cuab yeej indentation probe (zoo li, qhov loj, thiab lub caij nplooj ntoos hlav tawv), rhiab heev (tom qab nrov nrov thiab kev sib cuag taw tes kwv yees), thiab cov ntaub ntawv haum qauv (quantitative modulus ntsuas), txoj kev yog siv.ua tus qauv coj mus muag muaj ultra-mos kuaj los xyuas kom muaj nuj nqis.Kev lag luam polyacrylamide (PAAM) hydrogel nrog lub elastic modulus ntawm 1 kPa tau sim nyob rau hauv hydrated tej yam kev mob siv ib tug 140 nm sojntsuam.Cov ntsiab lus ntawm kev sim ntsuas thiab ntsuas ntsuas tau muab rau hauv Cov Lus Qhia Ntxiv.Cov txiaj ntsig tau pom tias qhov nruab nrab ntawm qhov ntsuas ntsuas yog 0.92 kPa, thiab qhov % RSD thiab feem pua ​​​​(%) sib txawv los ntawm cov qauv paub tau tsawg dua 10%.Cov txiaj ntsig no tau lees paub qhov raug thiab rov ua dua tshiab ntawm AFM nanoindentation txoj kev siv hauv kev ua haujlwm no los ntsuas cov qauv ntawm cov khoom siv ultrasoft.Qhov chaw ntawm lehfilcon A CL cov qauv thiab SiHy lub hauv paus substrate tau ntxiv tus cwj pwm siv tib txoj kev AFM nanoindentation los kawm txog qhov pom kev sib cuag ntawm lub ntsej muag ultrasoft raws li kev ua haujlwm ntawm indentation tob.Indentation quab yuam sib cais nkhaus tau tsim rau peb qhov qauv ntawm txhua hom (n = 3; ib qho indentation rau ib qho qauv) ntawm lub zog ntawm 300 pN, ceev ntawm 1 µm / s, thiab dej puv.Lub indentation quab yuam sib qhia nkhaus yog kwv yees siv lub cone-sphere qauv.Kom tau txais modulus nyob ntawm qhov tob indentation, 40 nm dav ib feem ntawm lub zog nkhaus tau teem rau ntawm txhua qhov increment ntawm 20 nm pib los ntawm qhov chaw ntawm kev sib cuag, thiab ntsuas qhov tseem ceeb ntawm cov modulus ntawm txhua kauj ruam ntawm lub zog nkhaus.Spin Cy et al.Ib txoj hauv kev zoo sib xws tau siv los ua tus cwj pwm ntawm cov qauv kev sib tw ntawm poly (lauryl methacrylate) (P12MA) polymer txhuam siv colloidal AFM sojntsuam nanoindentation, thiab lawv zoo ib yam nrog cov ntaub ntawv siv tus qauv hu rau Hertz.Txoj hauv kev no muab cov phiaj xwm pom meej ntawm kev sib cuag modulus (kPa) piv rau qhov tob tob (nm), raws li qhia hauv daim duab 8, uas qhia txog qhov pom kev sib cuag modulus/depth gradient.Qhov ntsuas elastic modulus ntawm CL lehfilcon A qauv yog nyob rau hauv thaj tsam ntawm 2-3 kPa nyob rau sab sauv 100 nm ntawm cov qauv, dhau qhov uas nws pib nce nrog qhov tob.Ntawm qhov tod tes, thaum sim SiHy lub hauv paus substrate yam tsis muaj txhuam zoo li zaj duab xis ntawm qhov chaw, qhov siab tshaj plaws indentation qhov tob ua tiav ntawm lub zog ntawm 300 pN yog tsawg dua 50 nm, thiab tus nqi modulus tau los ntawm cov ntaub ntawv yog li 400 kPa. , uas yog piv rau qhov tseem ceeb ntawm Young's modulus rau cov ntaub ntawv loj.
Pom meej kev sib cuag modulus (kPa) vs. indentation tob (nm) rau lehfilcon A CL thiab SiHy substrates siv AFM nanoindentation method nrog cone-sphere geometry los ntsuas modulus.
Qhov saum toj kawg nkaus ntawm qhov tshiab biomimetic branched polymer txhuam qauv nthuav tawm qhov tsis tshua muaj kev hloov pauv ntawm elasticity (2-3 kPa).Qhov no yuav phim qhov dawb dai kawg ntawm forked polymer txhuam raws li qhia hauv daim duab STEM.Txawm hais tias muaj qee cov pov thawj ntawm kev hloov pauv ntawm qhov chaw sab nrauv ntawm CL, lub ntsiab siab modulus substrate muaj kev cuam tshuam ntau dua.Txawm li cas los xij, sab saum toj 100 nm ntawm qhov saum npoo yog nyob rau hauv 20% ntawm tag nrho qhov ntev ntawm cov ceg ntoo polymer txhuam, yog li nws tsim nyog xav tias qhov ntsuas qhov ntsuas ntawm cov qauv hauv qhov indentation qhov tob yog qhov tseeb thiab tsis muaj zog. nyob ntawm qhov cuam tshuam ntawm cov khoom hauv qab.
Vim qhov tshwj xeeb biomimetic tsim ntawm lehfilcon A tiv thaiv lo ntsiab muag, muaj cov ceg ntawm PMPC polymer txhuam cov qauv grafted rau saum npoo ntawm SiHy substrates, nws yog qhov nyuaj heev rau kev ntseeg tau tias tus yam ntxwv ntawm cov khoom siv ntawm lawv cov qauv saum npoo siv cov qauv ntsuas.Ntawm no peb nthuav tawm cov txheej txheem AFM nanoindentation siab heev rau qhov ua tau zoo ntawm cov ntaub ntawv mos mos xws li lefilcon A nrog cov ntsiab lus dej siab thiab tsis tshua muaj siab elasticity.Txoj kev no yog ua raws li kev siv AFM sojntsuam uas nws qhov loj me thiab cov duab geometry tau ua tib zoo xaiv kom haum rau qhov ntev ntawm cov qauv ntawm lub ntsej muag ultra-soft yuav tsum tau imprinted.Qhov kev sib xyaw ua ke ntawm qhov ntev ntawm kev sojntsuam thiab cov qauv muab kev nkag siab ntau ntxiv, tso cai rau peb ntsuas cov qauv qis thiab cov khoom siv hauv lub cev ntawm cov ceg ntoo polymer txhuam, tsis hais txog cov teebmeem poroelastic.Cov txiaj ntsig tau pom tias qhov tshwj xeeb branched PMPC polymer txhuam tus yam ntxwv ntawm lub lens nto muaj qhov tsis tshua muaj elastic modulus (txog 2 kPa) thiab elasticity siab heev (ze li 100%) thaum kuaj hauv ib puag ncig aqueous.Cov txiaj ntsig ntawm AFM nanoindentation kuj tso cai rau peb los ua tus yam ntxwv ntawm kev sib cuag modulus / qhov tob gradient (30 kPa / 200 nm) ntawm biomimetic lens nto.Qhov gradient no tuaj yeem yog vim qhov sib txawv ntawm qhov sib txawv ntawm cov txhuam hniav polymer thiab SiHy substrate, los yog cov qauv ceg / qhov ntom ntawm cov txhuam hniav polymer, los yog kev sib xyaw ua ke.Txawm li cas los xij, kev tshawb fawb ntxiv rau qhov tob yog xav tau kom nkag siab txog kev sib raug zoo ntawm cov qauv thiab cov khoom, tshwj xeeb tshaj yog cov nyhuv ntawm txhuam ceg ntawm cov khoom siv kho tshuab.Cov kev ntsuas zoo sib xws tuaj yeem pab ua tus yam ntxwv ntawm cov khoom siv hluav taws xob ntawm qhov chaw ntawm lwm cov ntaub ntawv mos mos thiab cov khoom siv kho mob.
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