Ucwaningo Olusha Luthola Izimila Zezokwelapha Ze-Titanium Zisebenza Kakhulu
Inqubo ye-titanium yokuphrinta ye-3D
Uma kuqhathaniswa nenqubo yendabuko, izinzuzo zobuchwepheshe bokunyathelisa be-3D ukwenza izibalo zokufakelwa komuntu siqu zokuhlinzwa ziboniswa ngokuyinhloko ku-: 3D ukuphrinta izici zamahhala zokwakha zingakwazi ukwenza ngokwezifiso ukufakelwa kwangaphakathi ngokushesha nangokunembile, kunganqoba ukwakheka kwesibalo sokufakelwa kwendawo yonke akuhambelani nomzimba womuntu futhi izakhiwo zawo mechanical azifiki ezinkingeni ezijwayelekile; Ekwenziweni kwezakhiwo eziyinkimbinkimbi kanye nemikhiqizo okunzima ukuyicubungula, ama-micro-structures, ikakhulukazi ama-porous ngokusebenzisa izakhiwo, akakwazi ukuhlangabezana nezakhiwo ezithile zomzimba namakhemikhali, kodwa futhi athuthukise ukuhambisana kwe-biohistocompatibility.
Lolu chungechunge lwezinzuzo lunganqoba ngempumelelo izinkinga ezivamile zokuvikela ingcindezi kanye nomsebenzi ophansi webhayoloji wezimila. Njengamanje, ingxubevange ye-3D yokuphrinta ye-titanium esetshenziswa kakhulu futhi esetshenziswa kabanzi ubuchwepheshe be-SLM kanye nobuchwepheshe be-EBM.
I-Selective Laser Melting (SLM) isebenzisa i-laser njengomthombo wokushisa ukuze ukhethe ngokukhetha izinto eziyimpushana ezibekwe ngaphambili ukuze kuzuzwe ukuncibilika ngokushesha. Isimiso esiyinhloko sokusebenza ukuthi ngaphansi kwendawo yokuvikela igesi ye-inert, ithuluzi kanye nemishini ilawula ugongolo lwe-laser ngokusho kwendlela yokuskena yokugcwalisa eyenziwe yimodi yokuklama uhlelo ukuze ukhethe futhi uncibilikise ungqimba ngalunye lwe-powder.
Khona-ke isiteji sihanjiswa phansi, impushana iphinde ibekwe futhi i-sintering iphindwe kuze kube yilapho kwakheka konke. Ukuvikelwa kwegesi engenzi lutho kuvimbela insimbi ukuthi ingasabelani namanye amagesi emazingeni okushisa aphezulu. Ubuchwepheshe be-SLM bubanzi kakhulu bezinto zokwakha, ukonga impahla kanye nokusebenziseka kabusha, akudingi ukuklama nokulungiselela uhlelo lokusekela oluyinkimbinkimbi, lolu chungechunge lwezinzuzo lwenza ubuchwepheshe be-SLM busetshenziswe kabanzi.
Kodwa-ke, i-SLM nayo inezinye izithiyo: ngenxa yamandla we-laser alinganiselwe kanye nokuskena i-galvanometer deflection Angle, ububanzi bezingxenye ezilungiselelwe yi-SLM buzonqunywa; Ama-laser anamandla aphezulu kanye nemishini ye-optical yekhwalithi ephezulu kuyabiza ukwenza, okwandisa umthwalo wezomnotho ngezinga elithile. Ngenxa yokusetshenziswa kwezinto ze-powder kubuchwepheshe be-SLM, izinga eliphezulu lezingxenye ezibunjiwe lingase libe yinkinga, okudinga ukucutshungulwa kwesibili komkhiqizo okuzosetshenziselwa umsebenzi olandelayo; I-Spheroidization kanye nokukhubazeka kwe-warping kungase kwenzeke futhi enqubweni yokucubungula, okudinga esinye isinyathelo sokwandisa ngokuqinile inqubo yokucubungula I-Electron beam melting, i-EBM iyinqubo esebenzisa ugongolo lwe-electron njengomthombo wokushisa ukuncibilikisa ungqimba lwempuphu yensimbi ngongqimba endaweni ye-vacuum yokukhiqiza okungeziwe.
Isimiso salo sokusebenza sithi: impushana eboshwe ngaphambili, ukuchezuka kwe-electron ugongolo olunamandla amakhulu ngemva kokugxila ekukhiqizeni amandla aphezulu endaweni encane ukuze kuthwetshulwe ungqimba lwempushana ukuze kukhiqizwe izinga lokushisa eliphezulu ngisho nokuncibilika, ngokusebenzisa ukuskena kwe-electron ugongolo okuqhubekayo ukukhiqiza amandla phakathi kokuhlangana kwechibi lokuncibilika nokuqiniswa, okuxhunywe ungqimba lwensimbi oluqondile noluhleliwe.
Ngemva kokuqeda isendlalelo samanje, phinda umsebenzi wokubeka i-powder ukuze wakhe. Enqubweni yokukhiqiza, i-EBM yamukela imvelo yangempela yokuncibilika komoya ukuze kuqinisekiswe amandla aphezulu wento futhi igweme i-oxidation ye-alloy. Uma kuqhathaniswa ne-SLM, izinzuzo eziyinhloko ze-EBM yilezi: isizukulwane esisebenzayo samandla we-electron beam sisebenzisa amandla amancane, isivinini sokukhiqiza siphezulu, ukuze amandla angempela aphelele omshini wonke aphezulu; Ukuchezuka kwe-electron beam akudingi ukuhambisa ingxenye yesisetshenziswa, esithuthukisa nakakhulu isivinini sokuskena. Imvelo enhle eshisayo iqinisekisa ukuzinza komumo wezingxenye eziphrintiwe ze-3D, iqinisekisa izakhiwo zayo zemishini ezimile, ihlangabezana nezidingo zebhayoloji, futhi impushana yensimbi ingaphinda igaywe kabusha.
Isimo nenqubekelaphambili ye-3D ephrintiwe izimila zokuhlinza
Izimila zokuhlinza kanye nama-orthotics ane-3D printing anethuba elithembisayo lohlelo lokusebenza emkhakheni we-osteology. Manje sebebaningiIzinto zokufakelwa eziphrintiwe ze-3Dnjengokuzwa ingculazi, izitho zokufakelwa, imihlahlandlela yokuhlinza amathambo, amalunga okwenziwa, izindlebe zangaphandle zokwenziwa, izifakelo zamazinyo ezenzelwe wena kanye nezinye izinhlelo zokusebenza ekwelashweni komuntu siqu komtholampilo. Ngokwemibiko, ngo-2014, abacwaningi base-Peking University bafaka ngempumelelo umfana oneminyaka engu-12 ubudala nge-3D yomuntu siqu ephrintiwe umgogodla wokufakelwa onezimbobo ezincane, okwakuyicala lokuqala emhlabeni. Ngawo lowo nyaka, odokotela nososayensi bafakela intombazane eneminyaka engu-5 ubudala yaseScotland intende yesandla sokufakelwa ephrintiwe ye-3D.
I-Stomatology Specialty Centre yeSibhedlela sama-411 se-People's Liberation Army isebenzise ngempumelelo ubuchwepheshe be-EBM ukwenza ngokwezifiso nokufaka ingxube ye-mandibular titanium alloy ngokulingisa komuntu siqu okuphezulu kwe-anatomy yesiguli esikhishwe yi-hemimaxillary. Ngesikhathi sokusebenza, ukukhishwa kabusha kwe-mandible enesifo kanye nokulungiswa kokusebenza komuntu ngamunye kwaqedwa ngesikhathi esisodwa, futhi i-mandible enesici yalungiswa futhi yakhiwa kabusha. Umphumela wangemva kokuhlinzwa wawugculisa. U-Lethaus B nabanye abacwaningi basebenzisa ubuchwepheshe bokunyathelisa be-3D ukuze bakhe kabusha amathambo nama-microvascular flaps ezigulini ze-20 ezine-mandibular resection, okwanciphisa isikhathi sokusebenza futhi kwathuthukisa izinga lokusebenza, futhi umphumela wangemva kokuhlinzwa wawumuhle. Eminyakeni yamuva, izindaba ezifanayo kanye nocwaningo luye lwavela emfudlaneni ongapheli, okubonisa ngokugcwele amathemba okusebenza okuhle kokuphrinta kwe-3D emkhakheni wezokwelapha.
Ohlangothini lwemikhiqizo yamathambo, izinto zokufakelwa eziphrintiwe ze-3D nazo kancane kancane ziya ekuhwebeni nasekukhangiseni. Ngo-2007, izinkomishi ze-acetabulum eziphrintiwe ze-3D ze-bioprinted ezinezikhafula zezicubu eziqinile ezakhiwe inkampani yase-Italy i-Adler Ortho kanye ne-LIma-LTO yaphasisa isitifiketi se-CE. Umkhiqizo we-Exactech wagunyazwa yi-FDA ngo-2010. Ngo-2009, idivayisi yokuhlanganisa umzimba wonke we-titanium ekhiqizwa inkampani yaseMelika ye-AMT isebenzisa ukuphrinta kwe-3D nayo yaphumelela isitifiketi se-EU CE. Ngo-2013, umkhiqizo wokuqala wokufakelwa kogebhezi olunyathelisiwe e-United States wagunyazwa yi-FDA, okuphinde kube yisibalo sokuqala somhlaba esiphrintiwe se-PEEK sogebhezi se-3D esiphrintiwe.
Ngalesi sisekelo, ngo-2014, i-United States Oxford Company yathola imvume ye-FDA yemikhiqizo ye-3D yokuphrinta yamathambo e-maxillofacial (imodi engu-5IOK). Ngaphezu kwalokho, kubikwa ukuthi ngo-September 2015, ukufakelwa komuntu okuphrintiwe kwe-3D - i-hip joint artificial eyakhiwe yiSibhedlela Sesithathu Se-Beijing Medicine kanye ne-Beijing Aikang Yicheng Medical Equipment Co., LTD., ibhaliswe yi-State Food and Drug Administration. Inhlanganisela ye-hip ephrintiwe ye-3D ingene "esigabeni sokukhiqiza ngobuningi", okusho ukuthi izimila zokuphrinta ze-3D zaseChina nazo zingene esigabeni sokukhiqiza.
Ubuchwepheshe bokuphrinta be-3D buye babonisa indima ebaluleke kakhulu ekusungulweni kwesayensi yezokwelapha kanye nobuchwepheshe, futhi ucwaningo kanye nokusetshenziswa kwezitho zokufakelwa zokufakelwa komuntu siqu, izitho zokufakelwa, izifakelo zamazinyo nezinye izici nakho kubanzi kakhulu. Ngakho-ke, ukuhlolwa kwe-biosafety yezimila ezilungiselelwe yile nqubo entsha kudinga ukunakwa okwengeziwe.
Ucwaningo nge-biosafety ye-3D printing titanium
Ukuphepha kwezinto ze-biomedical kubonakala ikakhulukazi ekusebenzelaneni phakathi kwezicubu nezinto zokwakha. Ukuze izinto zensimbi ze-biomedical zihlangabezane nezindinganiso zamadivayisi afakiwe, kufanele kudingeke ukuthi ukusabela okubangelwa ukufakwa emzimbeni womuntu kusezingeni elamukelekayo, futhi ngesikhathi esifanayo, akukwazi ukuletha izinguquko zekhwalithi esakhiweni nasezimpahleni zezinto ezibonakalayo. Ukusebenzisana phakathi komzimba womuntu nomzimba womuntu kubonakala ikakhulukazi ekusebenzisaneni kwawo kwezinto eziphilayo kanye nomsebenzi wezinto eziphilayo.
Ngakho-ke, ngemva kokufakwa emzimbeni womuntu, ukufakelwa akufanele kubangele ukusabela okubi okufana nokungezwani komzimba, ukuvuvukala kanye namakhemikhali emangqamuzaneni omuntu, igazi nezitho zomzimba, noma ukwenqatshwa kwemizimba yangaphandle yabantu. Ngesikhathi esifanayo, kuyadingeka futhi ukuthi izimila ezidinga ukufakwa isikhathi eside kufanele zibe nezakhiwo ezinhle ze-static mechanical, okungukuthi, amandla anele, i-modulus elastic efanelekile, ukuzinza okuphezulu, ukumelana nokugqwala okuhle nokuqina okuqinile. Manje ukufakwa ngokuhlinzwa kwe-titanium alloy kusetshenziswa kabanzi emisebenzini yomtholampilo, futhi ucwaningo lwe-biocompatibility nalo seluvuthiwe. Ngakho-ke, ukuphepha kwezingxenye ze-titanium alloy ezihlobene nokuphrinta kwe-3D kugxile kakhulu ekuphepheni komsebenzi wayo we-biomechanical.
Ucwaningo lokuthi ukufakelwa kwensimbi ephrintiwe ye-3D kuyaqhathaniswa yini nemikhiqizo evamile yokufakelwa yenqubo yendabuko ngokwezakhiwo zemishini, ukumelana nokugqwala kanye nokuhambelana kwezinto eziphilayo, nokuthi ingabe ezinye zezindawo ezimile zokufakelwa kwe-alloy zingahlangabezana nokusetshenziswa komtholampilo kanye namazinga kazwelonke asaqhubeka. Kutholwe ukuthi izakhiwo zemishini ezimile ingxenye ye-3D ephrintiwe ye-titanium implants ingahlangabezana nezidingo zomtholampilo. Amasampula e-Ti6A14V alungiselelwe indlela ye-EBM ahlolwe ngokuhlolwa okuqinile okuqondile kanye nokuhlolwa kokucindezela kwe-isostatic okushisayo. Imiphumela yabonisa ukuthi amandla amasampula e-TI6A14V adlule izinga lokukhohlisa.
Ukumelana nokugqwala kwengxubevange ye-Co-Cr-Mo elungiselelwe ubuchwepheshe be-SLM kufana nalokho kwengxubevange elungiselelwe inqubo yendabuko, futhi inani lokuncibilika kwe-ion endaweni yokulingisa yamathe lingaphansi kokuphrinta kwe-3D kunalelo lengxubevange yenqubo yendabuko. Umkhiqizo we-Ti6A14V olungiselelwe ubuchwepheshe be-DMLS utholwe yinkampani ye-EOS ukuthi unezindawo zokuma mechanical ezimile kanye nokumelana nokukhathala njengokuqanjwa kwendabuko ngokucubungula okuphusile. Ithuluzi lokuhlanganisa i-titanium alloy vertebrae fusion elimbobozekile elilungiswe yi-EBM lafakwa emzimbeni wembuzi futhi lazuza imiphumela emihle kumodeli yokuhlanganiswa komlomo wesibeletho yezimvu. Isixhumi esibonakalayo sethambo besingcono kunedivayisi yokuhlanganisa ye-PEEK.
Ngokomtholampilo, i-elastic modulus nezinye izakhiwo zemishini ye-titanium alloy azihambisani nezakhiwo zethambo lomuntu, okuzoholela esimweni "sokuvikela ukucindezeleka" ku-peripheral bone tissue of the implant futhi kubangele i-osteoporosis, okuholela ekumunceni kwamathambo, ukuxegiswa nokulahlekelwa kokufakelwa nokwehluleka. Ukuze kuncishiswe le nkinga ngokufakwa kwe-titanium, izimila zesakhiwo ezinama-porous ziye zangena emehlweni abacwaningi. Manje, ucwaningo selukhombisile ukuthi ukuphrinta kwe-3D kungalungisa i-microstructure yezimila ngokunemba okuphezulu ukuze kuguqulwe i-elastic modulus yazo kanye nezakhiwo zemishini, ukuze zihambisane nezicubu zamathambo omuntu futhi zithuthukise imisebenzi ye-biomechanical ngesisekelo sokuqinisekisa umthwalo ofanele wokuphila.
Isakhiwo esilawulwayo somzimba we-Ti6AI4V sakhiwe ubuchwepheshe bokwenza i-EBM, futhi isakhiwo se-void yangaphakathi satholwa sihambisana nedizayini yethiyori ngaphansi kwe-scan electron microscopy, ezuze ukulawula okunembile kwe-EBM esakhiweni semikhiqizo ephrintiwe ye-3D. Ngokuhlolwa kokusebenza komshini, amandla acindezelayo ahambisanayo yi-163MPa kanye ne-elastic modulus engu-14MPa ku-60.1% pore porosity, eseduze nethambo lomuntu. Isiko le-in vitro cell libuye lakhombisa ukuhambisana okuhle kwamaseli.
Ama-scaffolds anezimbotshana alungiswe ubuchwepheshe be-EBM ngokusebenzisa ukwenziwa kahle kwamapharamitha wokuklama, futhi izakhiwo zabo zemishini zahlolwa. Kutholwe ukuthi i-biomechanics yezinto eziklanyelwe ezinama-porous zinezinga eliphezulu lokuphakama ekufaniseni ukuhambisana kwesigaba kanye nokuhlotshaniswa kokufakelwa. Izinhlobo ezintathu ze-titanium enezimbotshana ezine-300gm, 600gm kanye ne-900~tm ezilungiselelwe i-SLM zafakwa ku-rabbit tibia ukuze kuphenywe umphumela we-pore ratio ekukhuleni kwamathambo. Imiphumela yabonisa ukuthi izicubu zethambo ezinokwakheka kwe-600 ~ m ezinezimbotshana ezinobude obungcono kanye nokuvumelana kwe-biocompatibility.
Ngokombono wokukhula kwamathambo, i-scaffold ene-porosity eguquguqukayo kanye ne-aperture izoba lula kakhulu ekudluliseleni nasekudluliseleni izakhi emzimbeni womuntu, futhi ingakhuthaza ikhono lokukhula kwamathambo, ikhulise inhlanganisela yokufakelwa kanye nemibhede yamathambo, futhi yandise impilo yesevisi ye-prosthesis, ukuze uthole imiphumela engcono yezokwelapha kunesakhiwo esiqinile i-titanium alloy. Eminyakeni yamuva, i-multi-hole titanium alloy igxathu negxathu ibhekwa njengendlela ekahle kakhulu yomtholampilo entsha yokulungisa izicubu eziqinile kanye nezinto ezishintshwayo, futhi ukusetshenziswa kwezimila ze-3D eziphrintiwe ze-titanium alloy ezinezakhiwo ezihlukahlukene ezincane noma ngokusebenzisa izakhiwo kuye kwavula insimu entsha.