이 작품은 음식과 농업에 대한 USDA 국립 연구소, 국립 경쟁 보조금 프로그램, 국가 연구 이니셔티브 프로그램 71.1 FY 2007에 의해 부분적으로 자금 지원 알레르기 및 감염성 질환 그랜트 번호 2007-35503-18392, 보건 국립 연구소, 연구소 등 , R33AI94514-03.

1 회전 마약 준비 <ol><li> 이러한 계산에서 생체 고분자 분말의 수분 함량을 고려 반드시 생체 고분자의 농도 범위 (/ V 와트, 30 %, 0.1 %)을 조사하도록 준비한다. 각각의 농도를 들어, 50 ㎖의 시험관에 생체 고분자 (전분 또는 풀루 란) 분말을 무게. 수성 디메틸 설폭 사이드 (DMSO) 용액과 교반 막대를 추가합니다. </li><li> 자석 교반기의 핫 플레이트에 일정한 교반 끓는 물에 튜브를 놓습니다. </li><li> 약 1 시간 후, 열을 끄고 분산액을 실온으로 냉각되도록. 분산 물을 유동 학적 검사와 전기 방사를위한 준비가되어있다. </li></ol> 2 꾸준한 전단 유변학 <ol><li> 레오 미터를 따뜻하게하고 20 ° C에서 무대 온도를 설정합니다. 프로브 (사용 25mm 콘) 및 스테이지 (판) 사이의 격차를 보정합니다. </li><li> 상기 스테이지의 중심 상 생체 고분자 분산액 0.41 ㎖의 부하 positi를 설정하는 프로브를 낮출(25mm 콘에 대한 0.053 mm 간격)에. 분산이 균등하게 간격 내에서 확산 있는지 확인합니다. </li><li> 다음 실험 매개 변수 유변학 테스트를 수행 스윕 모드 : 로그인, 초기 속도 : 100 초 -1, 최종 속도 : 0.1 초 -1, 십 년간 당 포인트 : 10, 측정 전에 지연 : 5 초, 시간을 측정 : 10 초, 측정 기준과 방향 : 두 (시계 및 반 시계 방향 모두). </li><li> 시험을 전기 방사에 적합한 분산 농도를 추정하기 위해 유동 학적 데이터를 분석 할 수 있습니다. <ol><li> 중합체 농도의 함수로서 전단 율 대 겉보기 전단 점도 플롯. 0.1 초에서 겉보기 점도 (낮은 전단 속도 데이터가 신뢰할 낮은 농도에서 예) 실제 또는 추정 값을 기준으로 각 플로우 곡선, 대략 제로 전단 점도, η 0, 용 - 1. </li><li> 특정 점도를 계산 η 특검팀 = (η 0 - η들)η S는 용매의 점도 / s의 η. </li><li> 농도의 함수로서 고유 점도 플롯. semidilute unentangled 얽힌 정권을 확인합니다. semidilute unentangled 정권 작은 기울기 저농도 끝에서 시작하고, semidilute 교락 정권 unentangled 정권 다음 더 큰 경사를 갖는다. 두 정권에 맞추기 지수 법칙 회귀 모델. 전력 값은 로그 - 로그 플롯에 semidilute unentangled 낙합 정권과 경사면 (농도 의존성)이다. 이 장착 선의 교차점 얽힘 농도, C 전자이다. </li></ol></li></ol> 3 전기 방사 매개 변수 변화 <ol><li> 예를 들면, 15 %도 1에 도시 된 바와 같이. 전기 방사 셋업 조립 적절한 조성물의 분산액으로 주사기를 부하 (/ w를 v) 100 % DMSO에서, 주사기 펌프 상 전분 또는 풀루. 멋 부리 (고전압 와이어 클립바늘에 필자). 화장실에 접지 와이어 (음)을 담가 땅에 순수 에탄올을 포함하는 응고 욕을 연결합니다. 주사기 바늘과 응고 욕 사이의 거리를 조정하기 위해 랩 잭을 사용. 전기 방사 한 후 섬유 매트를 수집 조에서 금속 메쉬 담가. </li><li> 다음 매개 변수 범위의 생체 고분자를 스핀 : 이송 속도 0.1 ~ 0.4 ㎖ / 시간, 5-10cm 회전 거리와 전압에서 0 ~ 15 kV의에. <ol><li> 5cm의 회전 거리를 시작합니다. 제 이송 속도 (0.1 ㎖ / h)를 위해, 바늘 끝에서 압출 분산액의 형상으로 서서히 영 V. 결제주의로부터의 전압을 램프 업 및 적하 분산액 가속하고 기다란 때주의한다. </li><li> 작은 제트 솔루션의 electrospinnability를 나타내는 드롭 표면에서 시작되는 전압을합니다. 연속 제트가있는 경우, 시작되는 전압을 기록한다. </li><li> 세 paramete 각각에 대한 전체 범위를 검토RS 및 참고 성공적인 방사 조건. 끝에서 연속 제트있을 때에 만 섬유를 수집. </li></ol></li><li> 수집 몇 분 후, 순수 에탄올로 섬유 매트를 헹군다. 진공 상태에서 건조를 포함하는 데시 케이 터에 섬유 매트를 놓습니다. </li><li> 완전한 특성에 대한 각 생체 고분자의 농도에 대해 반복합니다. </li></ol><img alt="그림 1" fo:content-width="5in" src="/files/ftp_upload/51933/51933fig1highres.jpg" width="500" /> 전기 - 습식 방사 셋업도 1은 개략도. 생체 고분자 분산액을 주사기 펌프로부터 압출된다. 고전압 DC 전원이 무딘 바늘 근거 응고 욕에 높은 전압을 제공한다. 바늘 끝에서 폴리머 제트는 직선 경로를 통해 이동 한 다음 (일명 불안정성을 흔든다) 빠른 휘핑 경로를 개발하고 있습니다. (4) 형태 학적 특성<ol><li> 건조 섬유 매트의 조각을 잘라 탄소 테이프를 사용 SEM 스텁에 그것을 고정시킨다. </li><li> SEM 악기로 샘플 스텁을로드하고 분석을 위해 이미지를 얻을 수 있습니다. </li></ol>

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저자들은 공개 아무것도 없다는 것을 선언합니다.

레올 종래 섬유 방적을 포함하고 13 전기 방사 중합체의 처리를 연구하는 필수적인 도구이다. 정상 전단 유동 학적 연구, 고분자 형태 및 다른 용매에서의 상호 작용에서 해결 될 수 있습니다 (그림 2와 그림 3). 생체 고분자 분자들이 서로 중첩하기에 충분한 높은 농도에서, 그들의 농도 의존성은 좋은 용매 3,4 다른 중합체의보고 된 값과 잘 일치이었다 약 1.4 (도 ...

전기 방사는 다양한 물질로부터 나노 크기의 연속 마이크로 섬유를 제조 할 수있는 기술이다. 그것은 학문과 산업의 관심 일 증가 얻고있다. 설치 및 전기 방사의 연습은 간단 보이지만, 섬유 속성을 electrospinnability을 예측하고 제어 할 수있는 능력은 과제로 남아. 그 이유는 전기 방사 (2) 및 프로세스, 특히 섬유에 의해 이동 경로 일 것이다 혼란을 좌우하는 여러 가지 요인이 있다는 사실에 놓여있다. 종종 경험 &quot;보고 요리 -와 -&quot;접근 방식은 잠재적 electrospinnable 물질을 선별하는 데 사용됩니다. 그러나, 전기 방사를 더 잘 제어 및 합성 섬유의 특성, 필요 electrospinnability을 지배하는 메커니즘에 대한 이해를 돕기 있습니다. 몇몇 연구자들은 원액에 중합체의 분자의 얽힘이 된 essentia 것을 발견성공적인 전기 방사 3 - 5 리터의 필수 조건. 레올 로지 고분자 분산 분자 형태와 상호 작용을 조사 할 수있는 강력한 도구입니다. 예를 들어는 맥키 등. 클로로포름 / 디메틸 테레 프탈레이트 (7/3, v / v)로 함유하는 용매에 선형의 분자 형태 및 분 지형 폴리 (에틸렌 테레 프탈레이트 - 코 - 에틸렌 이소 프탈레이트) 공중 합체를 조사하고, 중합체 농도가 2-2.5x이어야 한 것으로 판단 성공적인 전기 방사 4 얽힘 농도. 때문에 생분해 성, 생체 적합성, 그리고 힘? 힘을 자신의 합성 대응 개성를에서 자신의 장점의 바이오 폴리머에서 섬유에서 현재 새롭게 관심이 있습니다. 그러나 실무자 열 처리 및 열등한 기계적 특성에 구조적 복잡성, 어려움에서 일반적으로 발생하는 많은 도전에 직면. 식물 조직에서 발견되는 전분은, 아몬이며g 지구상에서 가장 풍부하고 저렴한 바이오 폴리머. 순수 전분 섬유는 습식 전기 방사 장치는 최근 6 바와 이용하여 제조 하였다. 풀루 란 특정 박테리아에 의해 세포 외로 생산 선형 다당류이다. (1 → 4)와 (1 → 6)의 정규 교대는 glucosidic 채권은 능력 7,8를 형성하는 우수한 섬유 / 필름 포함 풀루 란의 여러 가지 독특한 속성에 대한 책임을 것으로 생각됩니다. 수성 분산액에서 풀루 섬유는 전기 방사 9,10 연구자들에 의해보고되었다. 이전 출판물에서이 바이오 폴리머, 전분 11, 풀루 란 (12)의 electrospinnability이 논의되고있다. 이 보고서는이 두 가지 생체 고분자의 electrospinnability의 조사에 유동 학적 원리를 활용하기위한 프로토콜을 시연에 초점을 맞추고 있습니다.

<table><tbody><tr><td>Gelose 80 starch</td><td>Ingredion</td><td></td><td>Used as it is</td></tr><tr><td>Pullulan</td><td>Hayashibara Co. Ltd</td><td></td><td>Used as it is</td></tr><tr><td>Dimethyl sulfoxide</td><td>BDH Chemicals</td><td>BDH1115-4LP</td><td></td></tr><tr><td>Ethanol</td><td>VWR International</td><td>89125-172</td><td>200 proof</td></tr><tr><td>Rheometer</td><td>TA Instruments</td><td>ARES&amp;nbsp;</td><td>50 mm cone and plate geometry</td></tr><tr><td>Syringe (10 ml)</td><td>Becton, Dickinson and Company</td><td>309604</td><td>Syringe with Luer-Lok&amp;reg; Tip</td></tr><tr><td>High voltage generator</td><td>Gamma High Voltage Research, Inc.</td><td>ES40P</td><td></td></tr><tr><td>Syringe pump</td><td>Hamilton Company</td><td>81620</td><td></td></tr><tr><td>Environmental scanning electron microscope</td><td>FEI Company</td><td>Quanta 200</td><td>for starch fibers</td></tr><tr><td>Environmental scanning electron microscope</td><td>Phenom-World</td><td>Phenom G2 Pro</td><td>for pullulan fibers</td></tr></tbody></table>

molecular entanglement and electrospinnability of biopolymers

전기 방사는 다양한 물질로부터 나노 섬유를 제조하는 마이크로 매혹적인 기술이다. 생체 고분자를 들어, 방사 도프의 성분 중합체의 분자의 얽힘이 성공적인 전기 방사를위한 필수적인 전제 조건 인 것으로 밝혀졌다. 유변학은 생체 고분자의 분자 형태와 상호 작용을 조사 할 수있는 강력한 도구입니다. 이 보고서에서, 우리는 디메틸 설폭 사이드 (DMSO) / 물 분산액으로부터,이 생체 고분자, 전분 및 풀루 란 electrospinnability을 평가 레올을 이용하는 프로토콜을 설명한다. 미크론 범위 미크론의 평균 직경을 갖는 잘 형성된 전분 및 풀루 섬유가 얻어졌다. Electrospinnability 형성 섬유의 시각 및 현미경 관찰에 의해 평가 하였다. 자신의 electrospinnability에 분산의 유변학 적 특성에 대한 상관 관계를 우리는 모든 당선자에 영향을 분자 형태, 분자 얽힘, 및 전단 점도 입증rospinning. 유 동학은 용매 시스템 선택 및 공정 최적화에 유용 할뿐만 아니라 분자 수준에서 섬유 형성의 메커니즘을 이해하지 않다.

생체 고분자 농도 및 용매 DMSO 농도의 함수로서 생체 고분자 분산액의 유동 곡선을 구 하였다. 두 대표적인 수치는 순수한 DMSO 용매에서의 농도의 함수로서 전분 (도 2A) 및 플루 란 (도 2b)의 유동 곡선을 나타낸다. 특정 점도는 생체 고분자 농도 (전분 그림 3a 및 풀루 란 그림 3B) 역모를 꾸몄다되었다. 이들 플롯에서, 엉킴 농도 semidilute unentangled 및 ...

Watch this Scientific Journal Video about Molecular Entanglement and Electrospinnability of Biopolymers at JoVE.com

Molecular Entanglement and Electrospinnability of Biopolymers

전기 방사는 다양한 물질에서 나노 스케일로 미세 섬유를 제조하는데 사용 매력적인 방법이다. 방사 도프의 성분 중합체의 분자의 얽힘이 성공적인 전기 방사에 필수적이다. 우리는이 생체 고분자, 전분 및 풀루 란 electrospinnability을 평가 레올 이용하는 프로토콜을 제시한다.

분자 얽힘과 생체 고분자의 Electrospinnability

Electrospinning is a fascinating technique to fabricate micro- to nano-scale fibers from a wide variety of materials. For biopolymers, molecular ...

molecular-entanglement-and-electrospinnability-of-biopolymers

Research

JoVE Journal

Bioengineering

13.9K 조회수.  Pennsylvania State University.  전기 방사는 다양한 물질에서 나노 스케일로 미세 섬유를 제조하는데 사용 매력적인 방법이다. 방사 도프의 성분 중합체의 분자의 얽힘이 성공적인 전기 방사에 필수적이다. 우리는이 생체 고분자, 전분 및 풀루 란 electrospinnability을 평가 레올 이용하는 프로토콜을 제시한다. 

비디오: Molecular Entanglement and Electrospinnability of Biopolymers

Electrospinning Fundamentals: Optimizing Solution and Apparatus Parameters

Electrospun nanofiber scaffolds have been shown to accelerate the maturation, improve the growth, and direct the migration of cells in vitro. Electrospinning is a process in which a charged polymer jet is collected on a grounded collector; a rapidly rotating collector results in aligned nanofibers while stationary collectors result in randomly oriented fiber mats. The polymer jet is formed when an applied electrostatic charge overcomes the surface tension of the solution. There is a minimum concentration for a given polymer, termed the critical entanglement concentration, below which a stable jet cannot be achieved and no nanofibers will form - although nanoparticles may be achieved (electrospray). A stable jet has two domains, a streaming segment and a whipping segment. While the whipping jet is usually invisible to the naked eye, the streaming segment is often visible under appropriate lighting conditions. Observing the length, thickness, consistency and movement of the stream is useful to predict the alignment and morphology of the nanofibers being formed. A short, non-uniform, inconsistent, and/or oscillating stream is indicative of a variety of problems, including poor fiber alignment, beading, splattering, and curlicue or wavy patterns. The stream can be optimized by adjusting the composition of the solution and the configuration of the electrospinning apparatus, thus optimizing the alignment and morphology of the fibers being produced. In this protocol, we present a procedure for setting up a basic electrospinning apparatus, empirically approximating the critical entanglement concentration of a polymer solution and optimizing the electrospinning process. In addition, we discuss some common problems and troubleshooting techniques.

Electrospinning techniques can create a variety of nanofibrous scaffolds for tissue engineering or other applications. We describe here a procedure to optimize the parameters of the electrospinning solution and apparatus to obtain fibers with the desired morphology and alignment. Common problems and troubleshooting techniques are also presented.

Electrospinning 기본 : 최적화 솔루션 및 장치 매개 변수

Electrospun nanofiber scaffolds have been shown to accelerate the maturation, improve the growth, and direct the migration of cells in vitro. ...

연구

생체공학

Air Filter Devices Including Nonwoven Meshes of Electrospun Recombinant Spider Silk Proteins

Based on the natural sequence of Araneus diadematus Fibroin 4 (ADF4), the recombinant spider silk protein eADF4(C16) has been engineered. This highly repetitive protein has a molecular weight of 48kDa and is soluble in different solvents (hexafluoroisopropanol (HFIP), formic acid and aqueous buffers). eADF4(C16) provides a high potential for various technical applications when processed into morphologies such as films, capsules, particles, hydrogels, coatings, fibers and nonwoven meshes. Due to their chemical stability and controlled morphology, the latter can be used to improve filter materials. In this protocol, we present a procedure to enhance the efficiency of different air filter devices, by deposition of nonwoven meshes of electrospun recombinant spider silk proteins. Electrospinning of eADF4(C16) dissolved in HFIP results in smooth fibers. Variation of the protein concentration (5-25% w/v) results in different fiber diameters (80-1,100 nm) and thus pore sizes of the nonwoven mesh.
Post-treatment of eADF4(C16) electrospun from HFIP is necessary since the protein displays a predominantly &alpha;-helical secondary structure in freshly spun fibers, and therefore the fibers are water soluble. Subsequent treatment with ethanol vapor induces formation of water resistant, stable &beta;-sheet structures, preserving the morphology of the silk fibers and meshes. Secondary structure analysis was performed using Fourier transform infrared spectroscopy (FTIR) and subsequent Fourier self-deconvolution (FSD).
The primary goal was to improve the filter efficiency of existing filter substrates by adding silk nonwoven layers on top. To evaluate the influence of electrospinning duration and thus nonwoven layer thickness on the filter efficiency, we performed air permeability tests in combination with particle deposition measurements. The experiments were carried out according to standard protocols.

Spider silk fibers display extraordinary mechanical properties. Engineered Araneus diadematus Fibroin 4 (eADF4) can be processed into nonwoven meshes using electrospinning. Here, the eADF4 nonwoven meshes are used to improve the performance of air filtering devices.

전기 방사 재조합 거미 실크 단백질의 부직포 메쉬를 포함하여 공기 정화 장치

Based on the natural sequence of Araneus diadematus Fibroin 4 (ADF4), the recombinant spider silk protein eADF4(C16) has been engineered. This highly ...

Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial applications. Here we describe how electrospinning or electrospraying a polymer mixture containing a biodegradable, biocompatible aliphatic polyester (e.g., polycaprolactone and poly(lactide-co-glycolide)), as the major component, doped with a hydrophobic copolymer composed of the polyester and a stearate-modified poly(glycerol carbonate) affords a superhydrophobic biomaterial. The fabrication techniques of electrospinning or electrospraying provide the enhanced surface roughness and porosity on and within the fibers or the particles, respectively. The use of a low surface energy copolymer dopant that blends with the polyester and can be stably electrospun or electrosprayed affords these superhydrophobic materials. Important parameters such as fiber size, copolymer dopant composition and/or concentration, and their effects on wettability are discussed. This combination of polymer chemistry and process engineering affords a versatile approach to develop application-specific materials using scalable techniques, which are likely generalizable to a wider class of polymers for a variety of applications.

Two- and three-dimensional superhydrophobic polymeric materials are prepared by electrospinning or electrospraying biodegradable polymers blended with a lower surface energy polymer of similar composition.

바이오 메디컬 응용 프로그램에 대한 초 소수성 고분자 재료를 제조

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial ...

Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning

While various smart materials have been explored for a variety of biomedical applications (e.g., drug delivery, tissue engineering, bioimaging, etc.), their ultimate clinical use has been hampered by the lack of biologically-relevant degradation observed for most smart materials. This is particularly true for temperature-responsive hydrogels, which are almost uniformly based on polymers that are functionally non-degradable (e.g., poly(N-isopropylacrylamide) (PNIPAM) or poly(oligoethylene glycol methacrylate) (POEGMA)). As such, to effectively translate the potential of thermoresponsive hydrogels to the challenges of remote-controlled or metabolism-regulated drug delivery, cell scaffolds with tunable cell-material interactions, theranostic materials with the potential for both imaging and drug delivery, and other such applications, a method is required to render the hydrogels (if not fully degradable) at least capable of renal clearance following the required lifetime of the material. To that end, this protocol describes the preparation of hydrolytically-degradable hydrazone-crosslinked hydrogels on multiple length scales based on the reaction between hydrazide and aldehyde-functionalized PNIPAM or POEGMA oligomers with molecular weights below the renal filtration limit. Specifically, methods to fabricate degradable thermoresponsive bulk hydrogels (using a double barrel syringe technique), hydrogel particles (on both the microscale through the use of a microfluidics platform facilitating simultaneous mixing and emulsification of the precursor polymers and the nanoscale through the use of a thermally-driven self-assembly and cross-linking method), and hydrogel nanofibers (using a reactive electrospinning strategy) are described. In each case, hydrogels with temperature-responsive properties similar to those achieved via conventional free radical cross-linking processes can be achieved, but the hydrazone cross-linked network can be degraded over time to re-form the oligomeric precursor polymers and enable clearance. As such, we anticipate these methods (which may be generically applied to any synthetic water-soluble polymer, not just smart materials) will enable easier translation of synthetic smart materials to clinical applications.

Protocols are described for the fabrication of degradable thermoresponsive hydrogels based on hydrazone cross-linking of polymeric oligomers on the bulk scale, microscale, and nanoscale, the latter for preparation of both gel nanoparticles and nanofibers.

자기 조립, 분해 Thermoresponsive Hydrogels 반응 압출, 마이크로, 통해 여러 길이 가늠 자에를 조작 하 고 전기

While various smart materials have been explored for a variety of biomedical applications (e.g., drug delivery, tissue engineering, bioimaging, etc.), ...

Methods for the Self-integration of Megamolecular Biopolymers on the Drying Air-LC Interface

Living organisms that use water are always prone to drying in the environment. Their activities are driven by biopolymer-based micro- and macro-structures, as seen in the cases of moving water in vascular bundles and moisturizing water in skin layers. In this study, we developed a method for assessing the effect of aqueous liquid crystalline (LC) solutions composed of biopolymers on drying. As LC biopolymers have megamolecular weight, we chose to study polysaccharides, cytoskeletal proteins, and DNA. The observation of biopolymer solutions during drying under polarized light reveals milliscale self-integration starting from the unstable air-LC interface. The dynamics of the aqueous LC biopolymer solutions can be monitored by evaporating water from a one-side-open cell. By analyzing the images taken using cross-polarized light, it is possible to recognize the spatio-temporal changes in the orientational order parameter. This method can be useful for the characterization of not only artificial materials in various fields, but also natural living tissues. We believe that it will provide an evaluation method for soft materials in the biomedical and environmental fields.

A method for the drying-induced self-integration of megamolecular biopolymers on the air-liquid crystalline interface is provided here. This methodology will be useful not only for understanding the macroscopic potentials of biopolymers, but also as an evaluation method for soft materials in biomedical and environmental fields.

건조 공기-LC 인터페이스에 Megamolecular 생체 고분자의 자체 통합을위한 방법

Living organisms that use water are always prone to drying in the environment. Their activities are driven by biopolymer-based micro- and ...

DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers

Mechanical properties of complex, polymer-based soft matter, such as cells or biopolymer networks, can be understood in neither the classical frame of flexible polymers nor of rigid rods. Underlying filaments remain outstretched due to their non-vanishing backbone stiffness, which is quantified via the persistence length (lp), but they are also subject to strong thermal fluctuations. Their finite bending stiffness leads to unique, non-trivial collective mechanics of bulk networks, enabling the formation of stable scaffolds at low volume fractions while providing large mesh sizes. This underlying principle is prevalent in nature (e.g., in cells or tissues), minimizing the high molecular content and thereby facilitating diffusive or active transport. Due to their biological implications and potential technological applications in biocompatible hydrogels, semiflexible polymers have been subject to considerable study. However, comprehensible investigations remained challenging since they relied on natural polymers, such as actin filaments, which are not freely tunable. Despite these limitations and due to the lack of synthetic, mechanically tunable, and semiflexible polymers, actin filaments were established as the common model system. A major limitation is that the central quantity lp cannot be freely tuned to study its impact on macroscopic bulk structures. This limitation was resolved by employing structurally programmable DNA nanotubes, enabling controlled alteration of the filament stiffness. They are formed through tile-based designs, where a discrete set of partially complementary strands hybridize in a ring structure with a discrete circumference. These rings feature sticky ends, enabling the effective polymerization into filaments several microns in length, and display similar polymerization kinetics as natural biopolymers. Due to their programmable mechanics, these tubes are versatile, novel tools to study the impact of lp on the single-molecule as well as the bulk scale. In contrast to actin filaments, they remain stable over weeks, without notable degeneration, and their handling is comparably straightforward.

Semiflexible polymers display unique mechanical properties that are extensively applied by living systems. However, systematic studies on biopolymers are limited since properties such as polymer rigidity are inaccessible. This manuscript describes how this limitation is circumvented by programmable DNA nanotubes, enabling experimental studies on the impact of filament rigidity.

Semiflexible 고분자 공부를 다양 한 도구로 DNA 나노튜브

Mechanical properties of complex, polymer-based soft matter, such as cells or biopolymer networks, can be understood in neither the classical frame of ...

Melt Electrospinning Writing of Three-dimensional Poly(&#949;-caprolactone) Scaffolds with Controllable Morphologies for Tissue Engineering Applications

This tutorial reflects on the fundamental principles and guidelines for electrospinning writing with polymer melts, an additive manufacturing technology with great potential for biomedical applications. The technique facilitates the direct deposition of biocompatible polymer fibers to fabricate well-ordered scaffolds in the sub-micron to micro scale range. The establishment of a stable, viscoelastic, polymer jet between a spinneret and a collector is achieved using an applied voltage and can be direct-written. A significant benefit of a typical porous scaffold is a high surface-to-volume ratio which provides increased effective adhesion sites for cell attachment and growth. Controlling the printing process by fine-tuning the system parameters enables high reproducibility in the quality of the printed scaffolds. It also provides a flexible manufacturing platform for users to tailor the morphological structures of the scaffolds to their specific requirements. For this purpose, we present a protocol to obtain different fiber diameters using melt electrospinning writing (MEW) with a guided amendment of the parameters, including flow rate, voltage and collection speed. Furthermore, we demonstrate how to optimize the jet, discuss often experienced technical challenges, explain troubleshooting techniques and showcase a wide range of printable scaffold architectures.

This protocol serves as a comprehensive guideline to fabricate scaffolds via electrospinning with polymer melts in a direct writing mode. We systematically outline the process and define the appropriate parameter settings for achieving targeted scaffold architectures.

조직 공학 응용 프로그램에 대 한 제어 형태학과 3 차원 Poly(ε-caprolactone) 장비의 전기 글 녹아

This tutorial reflects on the fundamental principles and guidelines for electrospinning writing with polymer melts, an additive manufacturing technology ...

Vapor Phase Deposition of Electroactive Poly(3,4-ethylenedioxythiophene) onto Electrospun Commodity Polymer Nanofibers

This study investigates the preparation of polyacrylonitrile (PAN) nanofibers through electrospinning to create highly porous and strong materials for applications in water purification, electrocatalysis, and biomedicine. The uniformly white PAN nanofiber mats were cut into 2 cm x 2 cm coupons to ensure consistency. After electrospinning, these nanofibers were coated with an electroactive polymer (EAP) using chemical vapor deposition, with iron (III) chloride (FeCl3) serving as an oxidant for polymerizing 3,4-ethylenedioxythiophene (EDOT) into poly(3,4-ethylenedioxythiophene) (PEDOT). The study examined the impact of different FeCl3 concentrations on PEDOT deposition on the PAN coupons. PEDOT deposition led to an increase in coupon weight. Scanning electron microscopy (SEM) revealed increases in the diameter of the nanofibers treated with increasing FeCl3 oxidant concentration, although higher FeCl3&#160;concentrations caused inter-fiber bridging, implying a concomitant decrease in inter-fiber spacing. Energy dispersive X-ray spectroscopy (EDS) was used to confirm the presence of Fe, Cl, and S in the nanofibers, with sulfur content rising with FeCl3&#160;concentration used, suggesting increased PEDOT deposition efficiency with increasing oxidant concentration. Mechanical testing showed that PEDOT-coated PAN fibers had improved tensile strength and toughness in the hydrated state compared to pure PAN nanofibers. These results highlight the crucial role of FeCl3&#160;concentration in influencing the morphology and properties of PAN-PEDOT composites, enhancing their suitability for applications such as water purification, tissue engineering, biosensing, catalysis, and energy storage.

This paper describes a simple technique for coating electrospun PAN nanofibers with electroactive polymers using vapor deposition. The effects of the oxidant FeCl&#8323; on the deposition of poly(3,4-ethylenedioxythiophene) coatings on PAN were investigated to understand and optimize polymer growth, fiber diameter, and overall mechanical strength of the nanofiber mats.

전기 방사 상품 고분자 나노 섬유에 전기 활성 폴리 (3,4- 에틸렌 디옥시 티오펜)의 기상 증착

This study investigates the preparation of polyacrylonitrile (PAN) nanofibers through electrospinning to create highly porous and strong materials for ...

화학

Controlling Electrospun Polymer Morphology for Tissue Engineering Demonstrated Using hepG2 Cell Line

Electrospinning affords researchers the opportunity to fabricate reproducible micro to nanoscale polymer fibers. The 3D fibrous architecture of electrospun polymers is regarded as a structural imitation of the extracellular matrix (ECM). Hence, electrospun fibers fabricated from biocompatible polymers have been widely investigated by tissue engineering researchers for their potential role as an artificial ECM for guiding tissue growth both in vitro and in vivo. All cells are acutely sensitive to their mechanical environment. This has been demonstrated by the discovery of multiple mechanotransduction pathways intrinsically linked to the cytoskeletal actin filaments. The cytoskeleton acts as a mechanical sensor that can direct the functionality and differentiation of the host cell depending on the stiffness and morphology of its substrate. Electrospun fibers can be tuned both in terms of fiber size and morphology to easily modulate the mechanical environment within a fibrous polymer scaffold. Here, methods for electrospinning polycaprolactone (PCL) for three distinct morphologies at two different fiber diameters are described. The morphological fiber categories consist of randomly oriented fibers, aligned fibers, and porous cryogenically spun fibers, with 1 &#181;m and 5 &#181;m diameters. The methods detailed within this study are proposed as a platform for investigating the effect of electrospun fiber architecture on tissue generation. Understanding these effects will allow researchers to optimize the mechanical properties of electrospun fibers and demonstrate the potential of this technology more thoroughly.

<meta charset="utf8"></head><body>hepG2 세포주를 사용하여 입증된 조직 공학을 위한 전기방사 고분자 형태 제어

This method provides the means to test different polycaprolactone fiber morphologies and topographies for the purpose of tissue engineering. Small and large fibers are fabricated with random orientations, aligned orientations, and also porous cryogenically electrospun structures and used as platforms for cell culture.