Kev npaj ntawm Hydrogel Microspheres los ntawm Hydroxypropyl Methyl Cellulose

Qhov kev sim no siv cov txheej txheem thim rov qab cov txheej txheem polymerization, siv hydroxypropyl methylcellulose (HPMC) raws li cov khoom siv raw, sodium hydroxide tov raws li theem dej, cyclohexane raws li cov roj theem, thiab divinyl sulfone (DVS) raws li kev sib txuas sib txuas ntawm Tween- 20 thiab Span-60 raws li ib tug dispersant, nplawm ntawm ib tug ceev ntawm 400-900r / min los npaj hydrogel microspheres.

Lo lus tseem ceeb: hydroxypropyl methylcellulose; hydrogel; microspheres; dispersant

1.Txheej txheem cej luam

1.1 Lub ntsiab lus ntawm hydrogel

Hydrogel (Hydrogel) yog ib yam ntawm cov molecular siab polymer uas muaj cov dej ntau hauv cov qauv network thiab yog insoluble hauv dej. Ib feem ntawm pawg hydrophobic thiab hydrophilic residues tau nkag mus rau hauv cov dej-soluble polymer nrog lub network crosslinked qauv, thiab hydrophilic Cov residues khi rau cov dej molecules, txuas cov dej molecules hauv lub network, thaum cov hydrophobic residues swell nrog dej los ua tus ntoo khaub lig. - txuas cov polymers. Jellies thiab qhov muag lo ntsiab muag hauv lub neej niaj hnub yog tag nrho cov khoom siv hydrogel. Raws li qhov loj thiab cov duab ntawm hydrogel, nws tuaj yeem muab faib ua macroscopic gel thiab microscopic gel (microsphere), thiab cov qub tuaj yeem muab faib ua columnar, porous sponge, fibrous, membranous, spherical, thiab lwm yam. Tam sim no npaj microspheres thiab nanoscale microspheres. muaj zoo softness, elasticity, kua cia muaj peev xwm thiab biocompatibility, thiab yog siv nyob rau hauv kev tshawb fawb ntawm entrapped tshuaj.

1.2 Qhov tseem ceeb ntawm kev xaiv lub ntsiab lus

Nyob rau hauv xyoo tas los no, txhawm rau ua kom tau raws li qhov yuav tsum tau muaj ntawm kev tiv thaiv ib puag ncig, cov ntaub ntawv polymer hydrogel tau maj mam nyiam cov neeg nyiam vim lawv cov khoom zoo hydrophilic thiab biocompatibility. Hydrogel microspheres tau npaj los ntawm hydroxypropyl methylcellulose ua raw khoom hauv qhov kev sim no. Hydroxypropyl methylcellulose yog non-ionic cellulose ether, hmoov dawb, tsis muaj ntxhiab thiab tsis qab, thiab muaj cov yam ntxwv tsis zoo ntawm lwm cov khoom siv hluavtaws polymer, yog li nws muaj txiaj ntsig kev tshawb fawb hauv cov khoom siv polymer.

1.3 Kev txhim kho nyob hauv tsev thiab txawv teb chaws

Hydrogel yog ib daim ntawv siv tshuaj uas tau nyiam ntau yam hauv zej zog kev kho mob thoob ntiaj teb hauv xyoo tas los no thiab tau tsim kho sai. Txij li thaum Wichterle thiab Lim tau tshaj tawm lawv txoj haujlwm pioneering ntawm HEMA cross-linked hydrogels hauv xyoo 1960, kev tshawb fawb thiab kev tshawb fawb ntawm hydrogels tau txuas ntxiv mus ntxiv. Nyob rau hauv nruab nrab-1970s, Tanaka nrhiav pH-sensitive hydrogels thaum ntsuas qhov o ntawm cov laus acrylamide gels, kos ib kauj ruam tshiab hauv kev kawm ntawm hydrogels. kuv lub teb chaws yog nyob rau theem ntawm hydrogel txoj kev loj hlob. Vim tias cov txheej txheem kev npaj dav dav ntawm cov tshuaj suav tshuaj suav tshuaj thiab cov khoom siv nyuaj, nws yog ib qho nyuaj rau rho tawm ib yam khoom ntshiab thaum ntau yam khoom ua haujlwm ua ke, thiab qhov ntau npaum li cas, yog li kev loj hlob ntawm Suav tshuaj hydrogel kuj yuav qeeb.

1.4 Cov ntaub ntawv sim thiab cov ntsiab lus

1.4.1 Hydroxypropyl methylcellulose

Hydroxypropyl methyl cellulose (HPMC), derivative ntawm methyl cellulose, yog ib qho tseem ceeb sib xyaw ether, uas belongs rau non-ionic dej-soluble polymers, thiab tsis muaj ntxhiab, tasteless thiab tsis muaj tshuaj lom.

Muaj HPMC yog nyob rau hauv daim ntawv ntawm cov hmoov dawb los yog dawb xoob fiber ntau, thiab nws cov aqueous tov muaj cov dej num nto, siab transparency thiab ruaj khov. Vim tias HPMC muaj cov khoom ntawm thermal gelation, cov khoom aqueous tov yog rhuab los ua ib tug gel thiab precipitates, thiab ces dissolves tom qab txias, thiab gelation kub ntawm txawv specifications ntawm cov khoom yog txawv. Cov khoom sib txawv ntawm HPMC kuj txawv. Lub solubility hloov nrog viscosity thiab tsis cuam tshuam los ntawm tus nqi pH. Qhov qis dua qhov viscosity, qhov ntau dua qhov solubility. Raws li cov ntsiab lus ntawm pawg methoxyl txo qis, qhov gel point ntawm HPMC nce, cov dej solubility txo, thiab cov dej ua haujlwm txo qis. Nyob rau hauv kev lag luam biomedical, nws yog tsuas yog siv raws li tus nqi-tswj cov khoom siv polymer rau txheej cov ntaub ntawv, cov ntaub ntawv zaj duab xis, thiab kev npaj tawm-tso tawm. Nws kuj tseem siv tau los ua tus stabilizer, tshem tawm tus neeg sawv cev, ntsiav tshuaj nplaum, thiab viscosity enhancer.

1.4.2 Txoj Cai

Siv cov txheej txheem thim rov qab cov txheej txheem polymerization, siv Tween-20, Span-60 compound dispersant thiab Tween-20 raws li cov dispersants cais, txiav txim siab HLB tus nqi (surfactant yog amphiphile nrog pab pawg hydrophilic thiab lipophilic pawg Molecule, tus nqi ntawm qhov loj thiab quab yuam. Qhov sib npaug ntawm pawg hydrophilic thiab pawg lipophilic nyob rau hauv surfactant molecule yog txhais raws li qhov kwv yees li ntawm qhov sib npaug ntawm hydrophilic-lipophilic tshuav nqi ntawm cov surfactant Cyclohexane tuaj yeem ua kom zoo dua cov tshuaj monomer dissipate Nyob rau hauv qhov kev sim tsis tu ncua, qhov ntau npaum yog 1-5 npaug ntawm cov tshuaj monomer aqueous nrog ib qho concentration ntawm 99% divinyl sulfone raws li tus neeg sawv cev sib txuas, thiab tus nqi ntawm tus neeg sawv cev sib txuas yog tswj ntawm li 10% ntawm. cov cellulose qhuav, yog li ntawd ntau linear molecules yog bonded rau ib leeg thiab cross-linked rau hauv ib tug network qauv Ib yam khoom uas covalently bonds los yog pab txhawb los yog ionic bond tsim ntawm polymer molecular chains.

Stirring yog ib qho tseem ceeb heev rau qhov kev sim no, thiab qhov ceev feem ntau yog tswj ntawm peb lossis plaub lub iav. Vim tias qhov loj ntawm qhov kev sib hloov ceev ncaj qha cuam tshuam qhov loj ntawm microspheres. Thaum qhov kev sib hloov ceev ntau dua 980r / min, yuav muaj qhov tshwm sim loj ntawm phab ntsa, uas yuav txo tau cov khoom tawm los; Tus neeg sawv cev sib txuas sib txuas zoo li tsim cov gels ntau, thiab cov khoom sib txuas tsis tuaj yeem tau txais.

2. Kev sim thiab cov txheej txheem

2.1 Cov cuab yeej sim

Hluav taws xob sib npaug, multifunctional electric stirrer, polarizing microscope, Malvern particle loj analyzer.

Txhawm rau npaj cellulose hydrogel microspheres, cov tshuaj tseem ceeb siv yog cyclohexane, Tween-20, Span-60, hydroxypropyl methylcellulose, divinyl sulfone, sodium hydroxide, dej distilled, tag nrho cov Monomers thiab additives yog siv ncaj qha yam tsis muaj kev kho mob.

2.2 Kev npaj cov kauj ruam ntawm cellulose hydrogel microspheres

2.2.1 Siv Tween 20 ua dispersant

Dissolution ntawm hydroxypropylmethylcellulose. Ua kom raug hnyav 2g ntawm sodium hydroxide thiab npaj 2% sodium hydroxide tov nrog 100ml ntim ntim. Noj 80 ml ntawm cov tshuaj sodium hydroxide npaj thiab muab tso rau hauv ib da dej rau li 50 feeb°C, hnyav 0.2g ntawm cellulose thiab ntxiv rau cov tshuaj alkaline, do nrog lub khob pas nrig, muab tso rau hauv dej txias rau da dej dej khov, thiab siv nws raws li theem dej tom qab kev daws teeb meem. Siv lub tog raj kheej kawm tiav los ntsuas 120ml ntawm cyclohexane (roj theem) rau hauv lub khob peb-caj dab, kos 5ml ntawm Tween-20 rau hauv cov roj theem nrog lub koob txhaj tshuaj, thiab do ntawm 700r / min rau ib teev. Noj ib nrab ntawm cov npaj aqueous theem thiab ntxiv rau lub khob peb-caj dab thiab do rau peb teev. Qhov concentration ntawm divinyl sulfone yog 99%, diluted rau 1% nrog dej distilled. Siv lub pipette coj 0.5ml ntawm DVS rau hauv 50ml volumetric hwj los npaj 1% DVS, 1ml ntawm DVS yog sib npaug rau 0.01g. Siv lub pipette coj 1ml rau hauv lub khob peb-caj dab. Do hauv chav sov li 22 teev.

2.2.2 Siv span60 thiab Tween-20 ua dispersants

Lwm ib nrab ntawm cov dej theem uas nyuam qhuav npaj. Qhov hnyav 0.01gspan60 thiab ntxiv rau hauv lub raj ntsuas, ua kom sov hauv 65-degree da dej kom txog thaum nws yaj, tom qab ntawd tso ob peb tee ntawm cyclohexane rau hauv dej da dej nrog cov roj hmab dropper, thiab kub kom txog thaum cov tshuaj hloov dawb. Ntxiv rau lub raj mis peb-caj dab, tom qab ntawd ntxiv 120ml ntawm cyclohexane, yaug lub raj nrog cyclohexane ob peb zaug, cua sov rau 5min, txias rau hauv chav sov, thiab ntxiv 0.5ml ntawm Tween-20. Tom qab stirring rau peb teev, 1ml ntawm diluted DVS tau ntxiv. Do hauv chav sov li 22 teev.

2.2.3 Cov txiaj ntsig kev sim

Cov qauv stirred yog dipped nyob rau hauv ib lub iav pas nrig thiab yaj nyob rau hauv 50ml ntawm kiag li ethanol, thiab particle loj yog ntsuas nyob rau hauv ib tug Malvern particle sizer. Siv Tween-20 raws li dispersant microemulsion yog thicker, thiab ntsuas particle loj ntawm 87.1% yog 455.2d.nm, thiab particle loj ntawm 12.9% yog 5026d.nm. Lub microemulsion ntawm Tween-20 thiab Span-60 mix dispersant zoo ib yam li cov mis nyuj, nrog 81.7% particle loj ntawm 5421d.nm thiab 18.3% particle loj ntawm 180.1d.nm.

3. Kev sib tham txog cov txiaj ntsig kev sim

Rau cov emulsifier rau kev npaj inverse microemulsion, nws yog feem ntau zoo dua los siv cov compound ntawm hydrophilic surfactant thiab lipophilic surfactant. Qhov no yog vim lub solubility ntawm ib tug surfactant nyob rau hauv lub system yog tsawg. Tom qab ob qho tib si sib xyaw ua ke, Ib leeg pawg hydrophilic thiab lipophilic pawg koom tes nrog ib leeg kom muaj cov nyhuv solubilizing. Tus nqi HLB kuj yog ib qho kev ntsuas feem ntau siv thaum xaiv emulsifiers. Los ntawm kev kho tus nqi HLB, qhov piv ntawm ob lub ntsiab lus emulsifier tuaj yeem ua kom zoo dua qub, thiab ntau yam microspheres tuaj yeem npaj tau. Hauv qhov kev sim no, tsis muaj zog lipophilic Span-60 (HLB = 4.7) thiab hydrophilic Tween-20 (HLB = 16.7) tau siv los ua cov dispersant, thiab Span-20 tau siv ib leeg ua tus dispersant. Los ntawm cov txiaj ntsig kev sim, nws tuaj yeem pom tau tias qhov sib xyaw ua ke Cov nyhuv zoo dua li ib qho dispersant. Lub microemulsion ntawm cov compound dispersant yog sib xws thiab muaj ib tug zoo li mis nyuj sib xws; cov microemulsion siv ib qho dispersant muaj viscosity siab dhau lawm thiab cov khoom dawb. Lub ncov me me tshwm nyob rau hauv lub compound dispersant ntawm Tween-20 thiab Span-60. Qhov laj thawj yog vim li cas qhov cuam tshuam ntawm qhov sib txuas ntawm qhov sib txuas ntawm Span-60 thiab Tween-20 yog qhov siab, thiab cov dispersant nws tus kheej tau tawg nyob rau hauv siab-siv stirring los tsim cov khoom zoo yuav cuam tshuam rau qhov kev sim. Qhov tsis zoo ntawm cov dispersant Tween-20 yog tias nws muaj ntau ntawm polyoxyethylene chains (n ​​= 20 los yog li ntawd), uas ua rau lub steric hindrance ntawm cov surfactant molecules loj thiab nws yog ib qho nyuaj rau ntom ntawm lub interface. Kev txiav txim los ntawm kev sib xyaw ntawm cov duab me me, cov khoom dawb hauv yuav yog cov cellulose undispersed. Yog li ntawd, cov txiaj ntsig ntawm qhov kev sim no qhia tias cov txiaj ntsig ntawm kev siv cov tshuaj dispersant zoo dua, thiab qhov kev sim tuaj yeem txo qis dua ntawm Tween-20 los ua kom cov microspheres npaj ntau dua.

Tsis tas li ntawd, qee qhov kev ua yuam kev hauv cov txheej txheem kev sim ua haujlwm yuav tsum raug txo kom tsawg, xws li kev npaj sodium hydroxide nyob rau hauv cov txheej txheem ntawm HPMC dissolution, dilution ntawm DVS, thiab lwm yam, yuav tsum tau standardized ntau npaum li sai tau los txo qhov kev sim ua yuam kev. Qhov tseem ceeb tshaj plaws yog tus nqi ntawm dispersant, qhov ceev thiab kev siv ntawm stirring, thiab tus nqi ntawm tus neeg sawv cev sib txuas. Tsuas yog thaum tswj tau zoo tuaj yeem npaj hydrogel microspheres nrog zoo dispersion thiab zoo li particle loj.