劉鐘 劉現(xiàn)峰 王學(xué)艷 張俊 于淼 相宏飛 陳勇 龍?jiān)茲?/p>
摘要: 針對(duì)傳統(tǒng)納米纖維制備裝置存在的運(yùn)輸困難、需要外部電源和靈活性差的現(xiàn)狀,為解決在醫(yī)學(xué)傷口敷料方面應(yīng)用受限的問(wèn)題,本文綜述了不依賴外部電源的小型便攜式靜電紡絲裝置組成和應(yīng)用。通過(guò)對(duì)電紡納米纖維的形態(tài)結(jié)構(gòu)、聚合物組成、抗菌性能、止血效果、促進(jìn)組織修復(fù)能力進(jìn)行討論,提出原位電紡的概念,即根據(jù)患者情況在傷口上直接快速制備納米纖維敷料膜,用于肝臟止血、燒燙傷處理、腦膜封閉等。最后,討論了便攜式靜電紡絲裝置在個(gè)性化美容和傷口敷料等方面的研究挑戰(zhàn)和發(fā)展趨勢(shì)。本綜述為便攜式靜電紡絲裝置的原位應(yīng)用提供參考。
關(guān)鍵詞:靜電紡絲; 聚合物納米纖維; 儀器; 醫(yī)學(xué)
中圖分類號(hào): TQ340.64; R318.08 文獻(xiàn)標(biāo)識(shí)碼: A
基金項(xiàng)目: 國(guó)家重點(diǎn)研發(fā)計(jì)劃(2019YFC0121402,2019YFC0121404,2019YFC0121405);國(guó)家自然科學(xué)基金(51973100,11904193);生物多糖纖維成形與生態(tài)紡織國(guó)家重點(diǎn)實(shí)驗(yàn)室(RZ2000003334);青島市博士后應(yīng)用研究項(xiàng)目(2020年)
靜電紡絲是一種納米纖維制造工藝,在高壓電場(chǎng)作用下,聚合物溶液或熔體經(jīng)噴射和延展,得到納米級(jí)纖維材料,并廣泛應(yīng)用于能源環(huán)境[1-2]、醫(yī)療保健[3-4]和納米器件開(kāi)發(fā)[5-6]等領(lǐng)域。特別是在近年來(lái)以傷口護(hù)理為代表的新興生物醫(yī)學(xué)領(lǐng)域,納米級(jí)纖維敷料形成的屏障不僅有助于保護(hù)傷口部位免受感染源的侵襲,而且透氣性好,止血更快[7-8]。醫(yī)用級(jí)靜電紡絲三維材料,可使納米纖維定向排列,從而引導(dǎo)細(xì)胞的定向生長(zhǎng)與遷徙[9],還可通過(guò)加工工藝對(duì)材料調(diào)控,使其與生物體達(dá)到良好的相容性與可降解性[10],其具有較高的比表面積和孔隙率,適合藥物遞送和細(xì)胞增殖[11]。同時(shí),還可制備支架材料[7-8,12-14],高度模擬體內(nèi)細(xì)胞外基質(zhì)(extracellular matrix,ECMs)結(jié)構(gòu),為軟組織再生提供適宜條件。傳統(tǒng)的傷口敷料是電紡網(wǎng)狀材料,其生產(chǎn)封裝好后擇機(jī)使用,但制備和使用分開(kāi)獨(dú)立。近年來(lái),為了制備應(yīng)用于傷口的理想敷料,一系列便攜式裝置相繼研發(fā)并面世,通過(guò)手持操作,可降解藥液在傷口上被直接噴涂成納米纖維,將制備和使用過(guò)程合二為一。這種在傷口上直接“原位”沉積納米纖維的方法,操作簡(jiǎn)單,減少疼痛和出血量,并可根據(jù)患者的個(gè)人需求定制敷料[8-19]。因此,隨著技術(shù)的不斷發(fā)展,能夠滿足個(gè)性化傷口護(hù)理的便攜式靜電紡絲裝置的需求日趨緊迫,而且該本文主要對(duì)便攜式靜電紡絲裝置在醫(yī)學(xué)上的應(yīng)用進(jìn)行研究,為便攜式靜電紡絲裝置的原位應(yīng)用提供理論依據(jù),應(yīng)用前景可期。
1靜電紡絲的原理
靜電紡絲技術(shù)始于1934年,20世紀(jì)90年代以來(lái),隨著納米技術(shù)的迅速發(fā)展,為制備微納米纖維提供了一種簡(jiǎn)單易行的方法。靜電紡絲制備的納米纖維如圖1所示。傳統(tǒng)靜電紡絲裝置包括高壓電源、紡絲噴頭、接地金屬收集器3部分(如圖1a所示)。纖維直徑從納米級(jí)調(diào)整到微米級(jí),直徑分布受溶液粘度、導(dǎo)電率、擠出率、靜電場(chǎng)、注射器直徑、選擇距離、溫度和濕度的影響[15]。由于高壓靜電場(chǎng)作用,聚合物溶液(或熔體)克服表面張力形成噴流,并隨著溶劑的蒸發(fā)或固化形成纖維,最終沉積在不同類型的收集器上,形成形態(tài)各異的纖維網(wǎng)(圖1b~圖1f),如紗線[16-20],或可直接組裝成其他取向各異的納米纖維[21-26]。
在紡絲過(guò)程中,聚合物溶液通過(guò)噴頭進(jìn)料,并施加高壓,增強(qiáng)的電場(chǎng)拉伸液滴,電荷產(chǎn)生相互作用,當(dāng)帶電荷溶液相互間的靜電斥力大于其表面張力時(shí),一束射流從錐頂噴出,形成泰勒?qǐng)A錐[27-28]。靜電紡絲聚合物射流[27-29]運(yùn)動(dòng)規(guī)律十分復(fù)雜,靜電紡絲射流路徑如圖2所示。射流在噴絲嘴的尖端可分為直線區(qū)、轉(zhuǎn)換區(qū)和不穩(wěn)定區(qū),圖2c展示了路徑不穩(wěn)定區(qū)的產(chǎn)生原理。首先形成一個(gè)帶有細(xì)長(zhǎng)包絡(luò)圓錐體的線圈,這個(gè)細(xì)長(zhǎng)的線圈形成一個(gè)較大的彎曲線圈,直徑增加更快,線圈內(nèi)部的灰色線表示形成“花環(huán)狀”較大線圈的中心線。
2便攜式靜電紡絲裝置的特點(diǎn)和優(yōu)勢(shì)
為實(shí)現(xiàn)纖維網(wǎng)中所需纖維的取向和形態(tài)的可控性[30-31],有必要對(duì)傳統(tǒng)制備工藝的各個(gè)方面進(jìn)行改良,例如噴頭和收集器的自組裝和改良,傳統(tǒng)靜電紡絲裝置的改良如圖3所示。Yang G等人[27]綜述了一些代表性策略,例如使用不同的噴頭[32-34](圖3b)、無(wú)針頭[35-38](圖3c)、集電器[39](圖3d)、平行電極[40](圖3e)、環(huán)形收集器[41-42](圖3f和圖3g)、轉(zhuǎn)盤收集器[43](圖3h)、平行軌道[44](圖3i)、水浴[45](圖3j)、動(dòng)態(tài)支撐系統(tǒng)[46](圖3k)、近場(chǎng)電紡[47](圖3l)、微流控[48](圖3m)以及3D打印[49](圖3n)。圖案化收集器也可用于生產(chǎn)復(fù)雜的纖維幾何形狀[50-52],需要固定尖端和離心噴絲頭才能形成定向納米纖維組件[53-55]。上述對(duì)靜電紡絲裝置的簡(jiǎn)單改良,可用于定制靜電紡絲網(wǎng)的結(jié)構(gòu)和性能,并且用于藥物輸送、組織工程和診斷等生物醫(yī)學(xué)領(lǐng)域[27]。組織修復(fù)是一個(gè)特殊的生物學(xué)過(guò)程,包括膠原代謝、傷口收縮、上皮形成及炎癥。如果便攜式靜電紡絲設(shè)備對(duì)應(yīng)的收集器是生物傷口的部位,僅依賴于某一部分(噴頭或收集器)的改良是不可行的。
為適應(yīng)生物收集體的特點(diǎn),迫切要求對(duì)大型標(biāo)準(zhǔn)臺(tái)式紡絲裝置的組件進(jìn)行改進(jìn),以提高便攜性和可操作性。模擬野外傷口緊急處理工作條件下,可使用內(nèi)置的鋰電池和高電壓轉(zhuǎn)換器來(lái)供電,無(wú)需外部電源供應(yīng),提高便攜性[56]。為解決高壓?jiǎn)卧图訜釂卧撵o電干擾,可將超高熱傳導(dǎo)和高絕緣單元內(nèi)置在頭部裝置中[57]。為精確沉積敷料,可使用定向罩輔助電紡,形成對(duì)傷口的定向性保護(hù)[58-59]。其它有效的改進(jìn)措施還包括手持式噴絲頭[60-64],使用帶轉(zhuǎn)換器的微型高壓電源[64-68],以及使用替代電源(電池或發(fā)電機(jī))[69-73]供電等。標(biāo)準(zhǔn)臺(tái)式裝置與便攜式裝置的優(yōu)缺點(diǎn)如下:
1)標(biāo)準(zhǔn)臺(tái)式。其優(yōu)點(diǎn)為環(huán)境參數(shù)可控,高壓可調(diào),電壓和流量數(shù)值精確,安全管理可靠。其缺點(diǎn)為運(yùn)輸困難,需要外部電源,靈活性差,價(jià)格昂貴。
2)便攜式。其優(yōu)點(diǎn)為便攜性(小巧,輕便,手持),方向靈活,應(yīng)用目標(biāo)廣泛,原位紡絲,手動(dòng)控制紡絲/噴涂,電池供電,使用安全,價(jià)格適中,滿足醫(yī)學(xué)應(yīng)用。其缺點(diǎn)為限流,高壓不穩(wěn)定,電池容量限制,固定尺寸。
便攜式靜電紡絲裝置的優(yōu)勢(shì),結(jié)合生物可降解聚合物、修復(fù)佐劑和組織替代品,使敷料具有抗菌、免疫調(diào)節(jié)、促細(xì)胞增殖和血管形成等多種功能。由于傷口類型較為復(fù)雜,如深度損傷[74]、表面積缺損[75]、燒燙傷[66,76]、內(nèi)臟切除后的傷口[77-78]和硬腦膜損傷[79],因此定制化的傷口處理十分關(guān)鍵。聚合物功能敷料、原位紡絲和精確沉積都為快速處理傷口部位、促進(jìn)傷口愈合提供了機(jī)會(huì)[80]。
3聚合物功能敷料
多種不同類型的便攜式電紡裝置已經(jīng)制備,為抗菌敷料在傷口上的快速應(yīng)用提供了機(jī)會(huì)。便攜式靜電紡絲材料的開(kāi)發(fā)對(duì)傷口敷料的發(fā)展至關(guān)重要[81],理想的功能敷料應(yīng)滿足止血迅速、抑菌和生物相容性高、創(chuàng)面粘附力強(qiáng)、透氣性好等特點(diǎn),因此一些抗菌劑被摻入納米纖維中,如中藥制劑、金屬和非金屬、醫(yī)用膠α氰基丙烯酸酯(Noctyl2cyanoacrylate,NOCA)等。靜電紡納米纖維在醫(yī)學(xué)(傷口敷料)中的應(yīng)用如表1所示。
目前,功能敷料的發(fā)展方向?yàn)楹?jiǎn)單、易用和多功能快速止血,多功能納米纖維敷料的制備和性能實(shí)驗(yàn)如圖4所示。Liu X F等人[89]使用便攜式靜電紡絲裝置合成CuS復(fù)合納米纖維(圖4a和圖4b),原位沉積在傷口上,在室外同時(shí)實(shí)現(xiàn)快速止血和抑菌,納米纖維不僅能快速止血(<6 s),而且能縮短銅綠假單胞菌感染創(chuàng)面的愈合時(shí)間(圖4c);Liu C L等人[90]通過(guò)原位沉積法制備了核殼結(jié)構(gòu)的光動(dòng)力納米纖維,能有效殺滅耐甲氧西林金黃色葡萄球菌,向創(chuàng)面輸送活性氧,增強(qiáng)光動(dòng)力效果,可作為抗菌敷料與止血?jiǎng)┙Y(jié)合使用。
4便攜式靜電紡絲裝置及其原位應(yīng)用
便攜式靜電紡絲裝置無(wú)需外部電源,內(nèi)置電源可運(yùn)行3 h以上[57],其體積小,重量輕,組件適合手持(單手在室內(nèi)和室外)操作,可在緊急情況或偏遠(yuǎn)地區(qū)使用。便攜式靜電紡絲裝置在操作過(guò)程中,內(nèi)部高壓經(jīng)特殊處理,總功率不足1 W,近距離(2~12 cm)操作無(wú)傷害,可放心使用[81]。為了提高裝置的便攜性,實(shí)現(xiàn)原位電紡的要求,以下綜述幾種便攜式靜電紡絲裝置及其原位應(yīng)用。
4.1手持靜電紡絲裝置及其原位應(yīng)用
Jiang K等人[62]首次設(shè)計(jì)一種氣流定向原位靜電紡絲裝置,氣流定向原位靜電紡絲裝置如圖5所示。
由圖5a可以看出,該裝置主要由高壓電源、注射泵、氣泵、自制噴絲頭手柄四部分組成。由圖5b可以看出,在氣流流速為12 L/min輔助下,可精確控制沉積范圍和位置,該裝置可作為書寫“靜電紡絲”等文字的筆。豬體內(nèi)原位肝臟止血實(shí)驗(yàn)如圖6所示。在麻醉?xiàng)l件下,從豬的腹腔中暴露一塊肝臟,并用一對(duì)止血鉗固定,部分肝臟被切開(kāi)后,傷口可見(jiàn)明顯出血,用無(wú)菌紗布和氣流進(jìn)一步清潔血液,然后用氣流定向原位靜電紡絲裝置在20 s內(nèi)迅速覆蓋一層NOCA纖維膜,1 min后取下止血鉗,3 h內(nèi)未見(jiàn)滲血。
Dong R H等人[82]使用新鮮離體動(dòng)物肝臟來(lái)建立肝切除術(shù)引起的出血模型,發(fā)現(xiàn)使用氣流定向裝置,不僅能將NOCA纖維精確沉積在傷口上,提高操作性能和安全性,而且顯著減少NOCA用量近80%,顯著降低毒副作用和炎性反應(yīng)。不同于噴涂法(使霧化涂料在高壓電場(chǎng)或氣流引導(dǎo)下吸附于基底表面)與傳統(tǒng)電紡法,氣流定向原位靜電紡絲法能夠精確沉積,高效止血,對(duì)肝細(xì)胞損傷小,有效促進(jìn)組織再生。用于體外止血實(shí)驗(yàn)的氣流定向原位靜電紡絲裝置如圖7所示。圖7c包括暴露肝臟,固定肝葉,切除肝臟,沉積NOCA膠等。由圖7c可以看出,噴頭距離傷口3~4 cm,傷口在10 s內(nèi)迅速被一層NOCA纖維膜覆蓋,切開(kāi)縫合線恢復(fù)肝血流后,未觀察到血液或膽汁滲出。
Lü F Y等人[79]還研究了原位電紡NOCA纖維用于山羊硬腦膜修復(fù),實(shí)驗(yàn)表明,這種方式紡成柔性、致密的膜不僅有助于快速縫合,而且能修復(fù)硬腦膜缺損,避免組織粘連,原位電紡NOCA纖維修復(fù)山羊硬腦膜實(shí)驗(yàn)如圖8所示。
在活體器官上原位沉積納米纖維可提高納米纖維膜與器官的粘附力,從而加速止血效果。Zhang J等人[83]將原位靜電紡絲和微創(chuàng)手術(shù)結(jié)合,通過(guò)腹腔鏡可視,并直接沉積到活體器官上,原位靜電紡絲和動(dòng)物微創(chuàng)止血手術(shù)如圖9所示。動(dòng)物微創(chuàng)手術(shù)通過(guò)一根長(zhǎng)的腹腔鏡管(37 cm)進(jìn)行(圖9a),可最大限度減少施術(shù)者手抖動(dòng)對(duì)傷口部位的影響。在腹腔鏡下,進(jìn)行長(zhǎng)針靜電紡絲裝置微創(chuàng)手術(shù)止血實(shí)驗(yàn)(圖9b),原位電紡法組(圖9g)止血時(shí)間5 s,優(yōu)于傳統(tǒng)縫合止血組(圖9e)止血時(shí)間3 min和涂抹NOCA組(圖9f)止血時(shí)間14 s。納米纖維膜的沉積面積可通過(guò)錐形會(huì)聚結(jié)構(gòu)和電紡距離進(jìn)行微調(diào),不影響纖維直徑。長(zhǎng)針靜電紡絲裝置結(jié)合腹腔鏡微創(chuàng)手術(shù)較傳統(tǒng)手術(shù)止血快,術(shù)后炎癥反應(yīng)小,恢復(fù)快。
2018年,Wang X X等人[91]報(bào)道了一種原位電紡制備的電子皮膚,原位電紡制備電子皮膚過(guò)程如圖10所示。研究采用聚偏氟乙烯(poly vinylidene fluoride,PVDF)納米纖維的單電極壓電納米發(fā)電機(jī)傳感器,插圖展示了它與神經(jīng)元細(xì)胞的相似性(圖10b),它由原位電紡制備(圖10a),可在單個(gè)單元上實(shí)現(xiàn)冷/熱集成壓力的穩(wěn)態(tài)傳感,壓電信號(hào)表現(xiàn)為方波信號(hào),熱敏信號(hào)表現(xiàn)為脈沖信號(hào),由這種納米纖維構(gòu)成的電子皮膚,可實(shí)現(xiàn)對(duì)溫度和壓力的高靈敏探測(cè)(圖10c~圖10e)。
針對(duì)腸道內(nèi)容物復(fù)雜,傷口密封要求更高的特點(diǎn),Zhou T T等人[84]將原位電紡應(yīng)用于豬離體腸道傷口止血,發(fā)現(xiàn)能有效防止腸道積液,納米纖維膜的平均直徑約為0.5 μm,可延長(zhǎng)90%而不斷裂,該裝置的便攜性和可控沉積,進(jìn)一步增加了原位電紡在傷口愈合中的應(yīng)用潛力。
4.2電池驅(qū)動(dòng)便攜式靜電紡絲裝置及其原位應(yīng)用
早期傳統(tǒng)紡絲裝置高壓和加熱組件需要220 V的工作電壓,沉重的設(shè)備體積,外部電源供應(yīng),在便攜性、可移植性方面存在短板。為了克服上述不足,已有研究報(bào)道了幾款不依賴外部電源供應(yīng)、電池驅(qū)動(dòng)的便攜式紡絲裝置[85-86],簡(jiǎn)介如下:
手持式熔體電紡裝置如圖11所示,重量約450 g,長(zhǎng)24 cm,厚6 cm,高13 cm。內(nèi)置的高壓?jiǎn)卧图訜釂卧耆煽沙潆婁囯姵毓╇?,可集成在設(shè)備內(nèi),內(nèi)置鋰電池可連續(xù)工作2 h以上(圖11b)。該裝置配有高效傳熱電絕緣單元,以解決加熱單元與高壓?jiǎn)卧g的靜電干擾。它便于攜帶,單手操作,纖維可直接沉積在另一只手上(圖11c)。利用該方法制備了直徑為4~17 μm的聚己內(nèi)酯(poly caprolactone, PCL)/Fe3O4磁性納米復(fù)合纖維,可將電磁能轉(zhuǎn)化為熱能,用于磁熱療。
手持式電池驅(qū)動(dòng)靜電紡絲裝置如圖12所示。包括裝置整機(jī)和一個(gè)用手指按壓的注射器(如圖12a所示)。采用兩節(jié)堿性電池提供3 V直流電壓,在高壓變頻轉(zhuǎn)換器的作用下,3 V電壓被放大到10 kV,轉(zhuǎn)換器的正極與注射器上的針頭相連,負(fù)極與用于操作裝置的導(dǎo)電金屬箔相連。該裝置可連續(xù)工作15 h以上,針頭與收集器工作距離在2~10 cm之間。實(shí)際質(zhì)量約120 g,長(zhǎng)5 cm,厚3 cm,高10.5 cm,不同方位外觀如圖12b所示。使用該裝置將聚乙烯吡咯烷酮(polyvinyl pyrrolidone, PVP)、PVDF和PCL靜電紡制備納米纖維敷料[81],用于大鼠體表傷口止血實(shí)驗(yàn)(如圖12c所示)。
抗菌劑和治療劑可結(jié)合在一起,以獲得多功能納米纖維膜,便攜式電紡裝置制備抗菌敷料實(shí)驗(yàn)如圖13所示。Dong R H等人[67]將載銀修飾介孔二氧化硅顆粒與PCL電紡成納米纖維膜(圖13a),發(fā)現(xiàn)隨著載銀質(zhì)量分?jǐn)?shù)從3%增加到8%,平均纖維直徑從389 nm增加到986 nm,纖維變得更加粗糙。載銀質(zhì)量分?jǐn)?shù)5%的納米纖維膜(平均纖維直徑658 nm)作為理想樣品,對(duì)金黃色葡萄球菌和大腸桿菌均具有良好的抗菌活性(圖13c),并可減輕Wistar大鼠的炎癥反應(yīng),促進(jìn)傷口愈合(圖13b和圖13c)。
定向罩輔助電紡沉積如圖14所示。為實(shí)現(xiàn)內(nèi)臟如肝、肺、腎等器官的快速止血,利用定向罩輔助電紡沉積過(guò)程,通過(guò)在紡絲噴嘴上安裝一個(gè)金屬錐,形成定向罩(圖14a),改變靜電場(chǎng)的分布,從而減少噴流發(fā)射角,調(diào)節(jié)電紡纖維的沉積范圍,以實(shí)現(xiàn)纖維的可控精密沉積[58-59]。調(diào)整電紡距離和金屬錐的邊長(zhǎng),可聚焦沉積面積(如圖14b和圖14c所示)。傳統(tǒng)的氣流輔助電紡需要一個(gè)附加的空氣泵電源,而定向罩輔助電紡不需要空氣泵電源,便攜性更好。但是由于電壓固定,限制了敷料的尺寸和物理性能,并且紡絲溶液的輸送取決于手指對(duì)扳機(jī)施加的壓力,在使用過(guò)程中,會(huì)導(dǎo)致纖維沉積不一致。
4.3發(fā)電機(jī)驅(qū)動(dòng)便攜式靜電紡絲裝置及其原位應(yīng)用
沒(méi)有外部電源,傳統(tǒng)的靜電紡絲裝置不能工作,手持靜電紡絲裝置的電池壽命仍有待提升。Han W P等人[69]設(shè)計(jì)了一種基于手動(dòng)Wimshurst發(fā)生器的自供電靜電紡絲裝置,使用Wimshurst發(fā)生器的紡絲裝置如圖15所示。
其中,圖15a為實(shí)物樣機(jī),其高壓部分被Wimshurst發(fā)生器所取代,通過(guò)轉(zhuǎn)動(dòng)手柄,使2個(gè)圓盤反向旋轉(zhuǎn),由于靜電感應(yīng)產(chǎn)生的正、負(fù)電荷分別儲(chǔ)存在2個(gè)萊登瓶中。隨著手柄的不斷轉(zhuǎn)動(dòng),電荷積累,然后在針和收集器之間產(chǎn)生高壓。利用該裝置成功的將聚苯乙烯(polystyrene,PS)、PVDF、PCL和聚乳酸(polylactic acid,PLA)等聚合物電紡成超薄纖維(圖15c和圖15e),2 min即可紡成幾厘米高的PS纖維三維堆垛結(jié)構(gòu)(圖15b),PLA纖維可原位靜電紡到皮膚上,快速成膜(圖15f),初步表明這種裝置可用于醫(yī)療美容領(lǐng)域。
Qin C C等人[87]通過(guò)更換錐形噴頭和添加帶溫度控制器的加熱槍,設(shè)計(jì)了基于Wimshurst發(fā)生器的自供電熔體靜電紡絲裝置,手動(dòng)Wimshurst發(fā)生器自供電熔體靜電紡絲裝置如圖16所示。
使用該裝置成功制備了直徑為15~45 μm的PLA和PCL超細(xì)纖維,纖維被直接熔融電紡到豬肝上(圖16c和圖16d),研究并優(yōu)化了紡絲速度(1.5 r/s)和紡絲距離(8~10 cm)對(duì)纖維的影響。測(cè)得沉積纖維的溫度(24~44 ℃)更接近人體溫度,PCL纖維的粘附性可達(dá)1.2 N,提示該裝置制備熔融電紡聚合物超細(xì)纖維適于傷口愈合。
除了電池供電和手動(dòng)發(fā)電,Yan X等人[71]介紹了一種太陽(yáng)能電池和手搖發(fā)電機(jī)驅(qū)動(dòng)的便攜式電紡裝置,太陽(yáng)能電池和手搖發(fā)電機(jī)驅(qū)動(dòng)的便攜式紡絲裝置如圖17所示。該裝置可在戶外使用,無(wú)需電源插頭(圖17a)。電源系統(tǒng)包括太陽(yáng)能電池(5 V/140 mA)、手持式發(fā)電機(jī)(5 V/200 mA)、一組可充電電池和高壓轉(zhuǎn)換器(圖17b)。該裝置可放在陽(yáng)光下通過(guò)太陽(yáng)能電池發(fā)電,也可通過(guò)轉(zhuǎn)動(dòng)發(fā)電機(jī)手柄給電池充電,為固定距離的溶液或熔融靜電紡絲提供持續(xù)電源。將噴絲頭和注射器改為錐形金屬噴嘴(圖17c和圖17d),聚合物顆??赏ㄟ^(guò)熱槍加熱成熔體,PCL、PLA和聚乳酸羥基乙酸共聚物(polylacticcoglycolic acid,PLGA)可通過(guò)該裝置熔融電紡成超細(xì)纖維(圖17e~圖17g)。
5結(jié)束語(yǔ)
從生物醫(yī)學(xué)的角度來(lái)看,靜電紡納米敷料是最有前途的納米材料,它們的形態(tài)尺寸與細(xì)胞外基質(zhì)結(jié)構(gòu)類似,高孔隙率可促進(jìn)細(xì)胞呼吸,柔韌性可促進(jìn)皮膚3D重組再生,還可作為抗菌藥物、生長(zhǎng)因子、維生素的有效載體。其優(yōu)點(diǎn)在于敷料不需要經(jīng)常更換,減少了人體疼痛和恐懼感,對(duì)于受試者十分容易接受。在過(guò)去幾年中,由電池或發(fā)電機(jī)供電的便攜式靜電紡絲裝置取得了重大進(jìn)展,性能和便攜性得到了系統(tǒng)性的提高,這些工作在一定情況下促進(jìn)了靜電紡絲技術(shù)在醫(yī)學(xué)領(lǐng)域的發(fā)展,未來(lái)還可考慮從以下方面進(jìn)一步研究,開(kāi)發(fā)對(duì)外部環(huán)境要求低、廉價(jià)、使止血藥物在創(chuàng)面精確沉積的紡絲裝置。評(píng)估各種功能材料適合手持靜電紡絲裝置和直接沉積在傷口部位,包括位于體表的傷口和體腔內(nèi)的深部傷口,能夠避免組織粘連,并可作為抗菌藥物、生長(zhǎng)因子的遞送載體,長(zhǎng)效、循環(huán)、可回收利用。多中心、大樣本的臨床前評(píng)估和體內(nèi)實(shí)驗(yàn),為定制個(gè)性化的美容和傷口敷料裝置的廣泛應(yīng)用提供了理論依據(jù)。
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作者簡(jiǎn)介: 劉鐘(1984),男,博士,主要研究方向?yàn)榧{米醫(yī)學(xué)材料。
通信作者: 龍?jiān)茲桑?977),男,教授,博士生導(dǎo)師,主要研究方向?yàn)楣δ芗{米纖維的制備、性能、應(yīng)用及產(chǎn)業(yè)化。Email: yunze.long@qdu.edu.cn
Application of Portable Electrospinning Devices in Medicine
LIU Zhong1, LIU Xianfeng1, WANG Xueyan1, ZHANG Jun1, YU Miao2, XIANG Hongfei3, CHEN Yong4, LONG Yunze1, 5
(1. College of Physics, Qingdao University, Qingdao 266071, China; 2. Qingdao Junada Technology Co. Ltd, Qingdao 266199, China;
3. Department of Orthopedics, The Affiliated Hospital of Qingdao University, Qingdao 266035, China;
4. Qingdao Yuren Medical Technology Co. Ltd, Qingdao 266111, China;
5. State Key Laboratory of BioFibers and EcoTextiles, Qingdao University, Qingdao 266071, China)
Abstract: ?For the current situation of difficult transportation, external power supply, and poor flexibility in traditional nanofiber preparation devices, in order to solve the problem of limited application in medical wound dressings, this paper summarizes the composition and medical application of small portable electrospinning devices independent of external power supply. By discussing the morphological structure, polymer compositions, antibacterial properties, hemostatic effect, and promoting tissue repair ability of electrospun nanofibers, the concept of insitu electrospinning is proposed, that is, the nanofibers dressings films are directly and quickly prepared on the wound according to the patient′s situation, especially in hemostasis of liver, burn and scald treatment, meningeal sealing, etc. Finally, the research challenge and development trend of portable electrospinning devices in individual cosmetic and wound dressings are considered for further study. This review provides a reference for the insitu application of portable electrospinning devices in medicine.