This research was supported by the Technology Innovation Program (Contract grant No. 0037915, WPM Biomedical Materials-Implant Materials) and Industrial Strategic Technology Development Program (Contract grant No. 10045329, Development of customized implant with porous structure for bone replacement), funded by the Ministry of Trade, industry &#38; Energy (MI, Korea), and BK21 PLUS SNU Materials Division for Educating Creative Global Leaders (Contract grant No. 21A20131912052).

1. A fabricação de andaimes metálicos porosos <ol><li> Prepare lamas Ti-canfeno por mistura em pó disponíveis comercialmente Ti, canfeno, e KD-4 depois de pesar as quantidades apropriadas de materiais como descrito na Tabela 1 para andaimes Ti porosos com porosidades quatro iniciais (40, 50, 60 e 70). Pour as suspensões em 500 ml de polietileno (PE) e rodar garrafas os frascos a 55 ° C durante 30 min num forno em moinho de bolas a 30 rpm. </li><li> Pour as lamas provenientes dos frascos de PE em alumínio cilíndrica (Al) moldes com um diâmetro de 60 mm e uma altura de 60 mm. Selar cada molde Al com a correspondente tampa de deslizamento Al e rodar os moldes numa estufa em moinho de bolas a uma velocidade de 30 rpm, a 55 ° C durante 10 min. <ol><li> Subsequentemente, diminuir a temperatura do forno em moinho de bolas a 44 ° C, e rodar continuamente os moldes a uma velocidade de 30 rpm, à temperatura constante de 44 ° C durante 12 h. </li></ol></li><li> Retire o molde da bola-moinho de forno rotativo depois adicionalmente os moldes à temperatura ambiente durante 1 h durante o processo de arrefecimento. Retire o corpo verde de titânio / camphene solidificado do molde Al usando um êmbolo Al. </li><li> Coloque o corpo verde de titânio / camphene solidificado em uma bolsa de borracha à mão e selar completamente o saco de borracha, amarrando a boca do saco com uma corda. Coloque o saco de borracha no reservatório de água de uma pressionando (CIP) máquina de frio isostática e aplicar uma pressão isostática de 200 MPa para 10 min. Retire o corpo verde comprimido do saco de borracha. </li><li> Transferir o corpo verde Ti-camphene para um cadinho de alumina com a mão e coloque o cadinho no congelar-máquina de secar roupa. Liofilizar o corpo verde para sublimar a fase canfeno no corpo verde a - 40 ° C durante 24 h. </li><li> Subsequentemente, fechar o cadinho com uma lamela de cobertura de alumina e colocar o cadinho fechado numa fornalha de vácuo (abaixo de 10 Torr -6) à TA. Em seguida, aumentar a temperatura do forno para 1300 ° C a uma r aquecimentoComeram de 5 ° C / min e manter a temperatura a 1300 ° C durante 2 horas. </li><li> Após o tratamento térmico, manter o sinterizado poroso Ti no forno durante 6-7 horas até que o forno é inteiramente arrefecida até à temperatura ambiente. Nota: Durante 6 horas do processo de arrefecimento, a taxa média de arrefecimento do forno acima de 400 ° C é de ~ 15 ° C / min e a velocidade média de arrefecimento do forno abaixo de 400 ° C é de ~ 2 ° C / min. </li><li> Se necessário, cortar o bloco de Ti sinterizado poroso em amostras em forma de disco com um diâmetro de 16 mm por meio de usinagem descarga elétrica (EDM). 27 Nota: Dependendo do tamanho dos moldes de Al, o tamanho do sinterizado poroso Ti precisa ser modificado através do processo de maquinação (Figura 2A). </li><li> Coloque um copo de vidro com as amostras porosas Ti num autoclave e esterilizar as amostras a 121 ° C durante 15 min. Retirar as amostras do autoclave. Lavam-se as amostras porosas de Ti com água destilada duas vezes e em seguida com etanol a 70% duas vezes.Finalmente, deixe a Ti porosa em uma placa de Petri e deixe secar as amostras em temperatura ambiente em um banco limpo sob luz UV. </li></ol> 2. Dip Coating de andaimes com agentes bioactivos <ol><li> Dilui-se a comercial Fluorescência verde Protein (GFP) a partir de 1 mg / ml a 100 ug / ml em um banco limpo por mistura de 1 ml de GFP com 9 ml de solução de Dulbecco Tamponado com Fosfato Salino (DPBS, pH 7,4) em um 10-esterilizado ml poliestireno (PS) do tubo, tal como indicado na Tabela 1. </li><li> Mergulha-se o esterilizado Ti densos ou porosos em 10 ml de solução diluída de GFP (100 ug / ml), colocando as amostras TI PS para dentro do tubo com a solução de GFP à TA e colocação num bancada limpa. </li><li> Colocar o tubo de PS num exsicador de vácuo e evacuar o exsicador durante 10 minutos para assegurar que a solução de GFP penetra nos poros do Ti poroso de forma mais eficaz. </li><li> Remover o titânio poroso a partir do tubo de PS utilizando pinças. Coloque a revestido poroso Ti-GFP em 10 cm de diâmetro Peprato tri e ar seco O / N à temperatura ambiente em um banco limpo. </li><li> Lavar o Ti poroso duas vezes com 10 ml de Dulbecco Tamponado com Fosfato Salino (DPBS) num copo de vidro, e mover o Ti poroso numa placa de Petri de diâmetro de 10 cm, usando uma pinça e ar seco, à temperatura ambiente numa bancada limpa. </li></ol> 3. Adensamento da porosas Andaimes <ol><li> Coloque as amostras TI-GFP porosos revestidos com várias alturas numa matriz de aço cilíndrica, e inserir um conjunto de punções para os orifícios superior e inferior do molde de aço (Figura 3A). </li><li> Comprimir a Ti poroso no interior do conjunto de matriz de aço, à TA na direcção z da amostra (Figura 3A), utilizando uma máquina de prensa em taxas de deformação intermédios de 0,05 ~ 0,1 seg -1 contra as estirpes aplicadas predeterminados mostrados na Tabela 2. Mantenha a pressão para 1 min antes da descarga. </li><li> Retirar as amostras Ti densificadas da matriz de aço. Lavam-se as amostras duas vezes densificadas com 10 ml de DPBSnuma proveta e O ar seco / N à TA numa bancada limpa. </li></ol> 4. Teste de lançamento de Andaimes revestido de GFP <ol><li> Imergir três tipos de amostras (revestido-GFP densa Ti (após os passos 2), revestida GFP-porosa Ti (após os passos 1 e 2) e revestido-GFP densificada poroso Ti (após os passos 1-3)) em 5 mL de DPBS (pH 7,4) solução contida em um tubo de 10 ml esterilizado PS a 37 ° C numa bancada limpa. </li><li> Sucção para fora toda a solução de DPBS de cada tubo PS com a amostra revestida de GFP e reabastecer com uma solução de DPBS novos 5 ml (pH 7,4) utilizando uma pipeta de acordo com os tempos pré-determinados de 1, 2, 3, 5, 8, 12, 15, 22 e 29 dias após a imersão. </li><li> Aqui as imagens de fluorescência das amostras revestidas de GFP antes da imersão (dia 0) e depois de 22 dias de imersão utilizando espectroscopia confocal de varrimento laser (CLSM). </li><li> Medir a intensidade de sinal de fluorescência da GFP libertado em 1 ml de solução a partir de um total de 5 ml de solução de DPBS retirada de cada tubo de PS na secção 4.2 usandoEspectroscopia de UV a um comprimento de onda de 215 nm. Converter o valor de intensidade para a concentração da solução de GFP usando a curva padrão. Nota: Antes da medição, desenhar a curva padrão de uma solução de GFP através da medição da intensidade do sinal de fluorescência da GFP em solução no intervalo de concentração de 0 ng / mL - 10 ng / ml. </li></ol> 5. Fabricação de Graded porosas Ti Andaimes <ol><li> Produzir um bloco do sinterizado Ti poroso repetindo o passo 1.1 para o passo 1.7. </li><li> Máquina do bloco Ti poroso sinterizado de acordo com os modelos de estrutura pré-determinados (por exemplo, a Figura 5A e 5d) por EDM. </li><li> Coloque as amostras maquinadas Ti com distribuição altura numa matriz de aço em que o diâmetro poroso de Ti é ~ 0,1 mm menor que o diâmetro do molde e inserir um conjunto de punções para os orifícios superior e inferior da matriz de aço. </li><li> Realize os passos 3.2 e 3.3. </li></ol> 6. A porosidade Measurement de Ti Andaimes <ol><li> Medir a massa (M s) de andaimes Ti. </li><li> Calcular o volume aparente (V s) pela medição de comprimento, largura e altura de andaimes Ti. </li><li> Calcular a porosidade usando a seguinte equação: <img alt="Equação 1" src="/files/ftp_upload/53279/53279eq1.jpg" /> onde P é a percentagem total de porosidade, ρ Ti é a densidade teórica do titânio e m S / V S é a densidade medida da amostra. Nota: A porosidade de amostras TI podem ser directamente recuperados a partir de imagens microCT após microCT imagiologia é efectuada utilizando um scanner de tomografia computadorizada de micro. </li></ol>

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The authors declare that they have no competing financial interests.

Embora os sistemas de Biometal têm sido amplamente utilizado para aplicações biomédicas, em particular, como materiais de suporte de carga, elevada rigidez e baixa bioactividade de metais têm sido consideradas como principais desafios. Neste estudo, foi estabelecido o método de fabricação de um novo sistema de metal, um andaime de metal poroso densificada que tem propriedades mecânicas, bem como biomiméticos superfície bioactiva com comportamento de libertação sustentável. As principais vantagens do nosso ...

Enquanto biomateriais metálicos têm sido amplamente utilizados como implantes de apoio de carga e dispositivos de fixação interna por causa da sua excelente resistência mecânica e elasticidade, 1-3 envolvem dois desafios importantes: 1) incompatibilidade mecânico porque os metais são muito mais rígidos do que os tecidos biológicos, causando danos indesejáveis para os tecidos circundantes e 2) baixa bioactividade que muitas vezes resulta em fraca relação com os tecidos biológicos, muitas vezes provocam reacções de corpos estranhos (por exemplo, inflamação ou trombose). 4-6 andaimes metálicos porosos têm sido propostos para promover o crescimento ósseo nas estruturas, melhorando . contacto osso-implante, enquanto os efeitos de stress de blindagem são suprimidos por causa da sua rigidez reduzida 7-9 Além disso, várias modificações da superfície ter sido aplicada para melhorar as actividades biológicas dos implantes metálicos; tais modificações incluem revestimento de superfície do metal com moléculas bioactivas (por exemplo, crescimento FACres) ou fármacos (por exemplo, vancomicina, tetraciclina) 10-12. No entanto, os problemas, tais como reduzidas propriedades mecânicas de andaimes de metal porosos, diminuição da rigidez e a libertação rápida das camadas de revestimento bioactivos continuam por resolver 13-16. Em particular, titânio (Ti) e Ti ligas são um dos sistemas Biometal mais populares por causa de suas excelentes propriedades mecânicas, estabilidade química, e boa biocompatibilidade. 13,17-19 Suas aplicações em forma de espuma, também têm atraído crescente interesse porque o 3D redes porosas promover crescimento ósseo, além das propriedades mecânicas do osso semelhantes. 20-22 Foram feitos esforços para melhorar as propriedades mecânicas através do desenvolvimento de novas técnicas de fabrico, incluindo a replicação de esponja polimérica, a sinterização de partículas de metal, de prototipagem rápida método (RP), e espaço método de suporte, a fim de controlar as várias características de poros (por exemplo, fracção de poros,forma, tamanho, distribuição e conectividade) e propriedades do material (por exemplo, fase metálica e de impurezas). 23-25 ​​Recentemente, a fundição congelamento de lodo em metal à base de água tem ganhado considerável atenção para produzir aprimorados mecanicamente formas Ti com poros bem alinhados estruturas, utilizando o unidireccional crescimento dendrítico gelo durante a solidificação; no entanto, a contaminação de oxigênio causada pelo contato de pós metálicos com água requer cuidados especiais para minimizar a fragilização de andaimes Ti. 14,15 Por isso, desenvolvemos uma nova abordagem para a fabricação de scaffolds bioativos Ti porosos e ajustáveis ​​mecanicamente. 25 Os andaimes inicialmente têm estruturas porosas com uma porosidade de mais de 50%. As matrizes porosas fabricadas foram revestidas com moléculas bioactivas e depois comprimida utilizando uma prensa mecânica durante os quais a porosidade final, as propriedades mecânicas e comportamento de libertação do fármaco foi controlada pela aplied tensão. Os implantes porosos densificadas Ti demonstraram baixa porosidade com boa resistência, apesar da baixa rigidez comparável à do osso (3-20 GPa). 2 Por causa da camada de revestimento, a bioactividade do densificada Ti poroso foi significativamente melhorada. Além disso, por causa das estruturas de poros planas originais induzidas pelo processo de densificação, as moléculas bioactivas revestidos foram vistos a ser gradualmente libertado a partir do andaime, mantendo a sua eficácia durante um período prolongado. Neste estudo, nós introduzimos nosso método estabelecido para fabricar densificadas andaimes Ti porosas para uso potencial em aplicações biomédicas. O protocolo inclui fundição congelamento dinâmica com lamas e densificação de scaffolds porosos metálicos. Em primeiro lugar, para o fabrico de andaimes Ti porosas com boa ductilidade do método de fundição de congelação dinâmica foi introduzido como mostrado na Figura 1A. Ti em pó foi disperso em canfeno líquido; em seguida, pela diminuição da temperatura,a fase líquida foi solidificada, resultando na separação de fase entre a rede de Ti em pó e cristais sólidos canfeno. Subsequentemente, o corpo verde solidificou Ti-canfeno foi sinterizado no qual pós de Ti foram condensados ​​com escoras contínuas Ti, e a fase de canfeno foi completamente removido para se obter uma estrutura porosa. O revestimento e processo de densificação com as matrizes porosas obtidas foi utilizado, variando o grau de densificação e porosidade inicial. A camada de revestimento e o seu comportamento de libertação foram visualizadas e quantificadas utilizando a proteína fluorescente verde (GFP) -Revestido poroso Ti com e sem densificação em comparação com a GFP denso revestido-Ti. Finalmente, andaimes Ti gradação funcional que têm duas estruturas porosas diferentes foram propostos e demonstrados através da variação do grau de densificação das partes internas e externas das matrizes porosas.

<table>
	<tbody>
		<tr>
			<td>Titanium powder</td>
			<td>Alfa Aesar</td>
			<td>#42624</td>
			<td>-325 mesh, 99.5% (metals basis)</td>
		</tr>
		<tr>
			<td>Camphene</td>
			<td>SigmaAldrich</td>
			<td>#456055</td>
			<td>95%, C10H16</td>
		</tr>
		<tr>
			<td>KD-4</td>
			<td>Croda</td>
			<td>&#173;</td>
			<td>Hypermer, polymeric dispersant</td>
		</tr>
		<tr>
			<td>Phosphate Buffer Solution (PBS)</td>
			<td>Welgene</td>
			<td>ML 008-01</td>
			<td>&#173;</td>
		</tr>
		<tr>
			<td>Green Fluorescent Protein (GFP)</td>
			<td>Genoss Co.</td>
			<td>-</td>
			<td>&#62;98% purity, 1mg/ml</td>
		</tr>
		<tr>
			<td>Ball mill oven</td>
			<td>SAMHENUG ENERGY</td>
			<td>SH-BDO150</td>
			<td>&#173;</td>
		</tr>
		<tr>
			<td>Freeze dryer</td>
			<td>Ilshin Lab.</td>
			<td>PVTFD50A</td>
			<td>&#173;</td>
		</tr>
		<tr>
			<td>Cold isostatic pressing (CIP) machine</td>
			<td>SONGWON SYSTEMS</td>
			<td>CIP 42260</td>
			<td>&#173;</td>
		</tr>
		<tr>
			<td>Vaccum furnace</td>
			<td>JEONG MIN INDUSTRIAL</td>
			<td>JM-HP20</td>
			<td>&#173;</td>
		</tr>
		<tr>
			<td>electical chaege machine</td>
			<td>FANUC robocut</td>
			<td>0iB</td>
			<td>External use</td>
		</tr>
		<tr>
			<td>Press machine</td>
			<td>CG&#38;S</td>
			<td>AJP-200</td>
			<td>&#173;</td>
		</tr>
		<tr>
			<td>Confocal laser scanning spectroscopy (CLSM)</td>
			<td>Olympus</td>
			<td>FluoView FV1000</td>
			<td>External use</td>
		</tr>
	</tbody>
</table>

fabrication of mechanically tunable and bioactive metal scaffolds for biomedical applications

Biometal systems have been widely used for biomedical applications, in particular, as load-bearing materials. However, major challenges are high stiffness and low bioactivity of metals. In this study, we have developed a new method towards fabricating a new type of bioactive and mechanically reliable porous metal scaffolds-densified porous Ti scaffolds. The method consists of two fabrication processes, 1) the fabrication of porous Ti scaffolds by dynamic freeze casting, and 2) coating and densification of the porous scaffolds. The dynamic freeze casting method to fabricate porous Ti scaffolds allowed the densification of porous scaffolds by minimizing the chemical contamination and structural defects. The densification process is distinctive for three reasons. First, the densification process is simple, because it requires a control of only one parameter (degree of densification). Second, it is effective, as it achieves mechanical enhancement and sustainable release of biomolecules from porous scaffolds. Third, it has broad applications, as it is also applicable to the fabrication of functionally graded porous scaffolds by spatially varied strain during densification.

O processo de fabrico usado para produzir suportes porosos Ti é ilustrado na Figura 1A. Ti é mantido em pó disperso homogeneamente em canfeno pela rotação contínua do recipiente a 44 ° C durante 12 h e, ao mesmo tempo canfeno líquido é totalmente solidificados, quaisquer sedimentos de pó Ti relativamente pesado pode ser minimizada. Como um resultado, o corpo verde homogénea Ti-canfeno foi produzido utilizando o processo de fundição de congelação dinâmica, como mostrado n...

Watch this Scientific Journal Video about Fabrication of Mechanically Tunable and Bioactive Metal Scaffolds for Biomedical Applications at JoVE.com

Fabrication of Mechanically Tunable and Bioactive Metal Scaffolds for Biomedical Applications

Bioactive and mechanically reliable metal scaffolds have been fabricated through a method which consists of two processes, dynamic freeze casting for the fabrication of porous Ti, and coating and densification of the Ti scaffolds. The densification process is simple, effective and applicable to the fabrication of functionally graded scaffolds.

Fabricação de Mecanicamente Tunable e Bioativos metal andaimes para aplicações biomédicas

Biometal systems have been widely used for biomedical applications, in particular, as load-bearing materials. However, major challenges are high stiffness ...

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10.6K visualizações.  Korea Institute of Industrial Technology. Bioactive and mechanically reliable metal scaffolds have been fabricated through a method which consists of two processes, dynamic freeze casting for the fabrication of porous Ti, and coating and densification of the Ti scaffolds. The densification process is simple, effective and applicable to the fabrication of functionally graded scaffolds.

Vídeo: Fabrication of Mechanically Tunable and Bioactive Metal Scaffolds for Biomedical Applications

Microfabricated Platforms for Mechanically Dynamic Cell Culture

The ability to systematically probe in vitro cellular response to combinations of mechanobiological stimuli for tissue engineering, drug discovery or fundamental cell biology studies is limited by current bioreactor technologies, which cannot simultaneously apply a variety of mechanical stimuli to cultured cells. In order to address this issue, we have developed a series of microfabricated platforms designed to screen for the effects of mechanical stimuli in a high-throughput format. In this protocol, we demonstrate the fabrication of a microactuator array of vertically displaced posts on which the technology is based, and further demonstrate how this base technology can be modified to conduct high-throughput mechanically dynamic cell culture in both two-dimensional and three-dimensional culture paradigms.

In this protocol, we demonstrate the fabrication of a microactuator array of vertically displaced posts on which the technology is based, and how this base technology can be modified to conduct high-throughput mechanically dynamic cell culture in both two-dimensional and three-dimensional culture paradigms.

Plataformas microfabricated para cultura de células mecanicamente dinâmico

The ability to systematically probe in vitro cellular response to combinations of mechanobiological stimuli for tissue engineering, drug discovery or ...

Bioengenharia

Preparation of 3D Fibrin Scaffolds for Stem Cell Culture Applications

Stem cells are found in naturally occurring 3D microenvironments in vivo, which are often referred to as the stem cell niche 1. Culturing stem cells inside of 3D biomaterial scaffolds provides a way to accurately mimic these microenvironments, providing an advantage over traditional 2D culture methods using polystyrene as well as a method for engineering replacement tissues 2. While 2D tissue culture polystrene has been used for the majority of cell culture experiments, 3D biomaterial scaffolds can more closely replicate the microenvironments found in vivo by enabling more accurate establishment of cell polarity in the environment and possessing biochemical and mechanical properties similar to soft tissue.3 A variety of naturally derived and synthetic biomaterial scaffolds have been investigated as 3D environments for supporting stem cell growth. While synthetic scaffolds can be synthesized to have a greater range of mechanical and chemical properties and often have greater reproducibility, natural biomaterials are often composed of proteins and polysaccharides found in the extracelluar matrix and as a result contain binding sites for cell adhesion and readily support cell culture. Fibrin scaffolds, produced by polymerizing the protein fibrinogen obtained from plasma, have been widely investigated for a variety of tissue engineering applications both in vitro and in vivo 4. Such scaffolds can be modified using a variety of methods to incorporate controlled release systems for delivering therapeutic factors 5. Previous work has shown that such scaffolds can be used to successfully culture embryonic stem cells and this scaffold-based culture system can be used to screen the effects of various growth factors on the differentiation of the stem cells seeded inside 6,7.
 This protocol details the process of polymerizing fibrin scaffolds from fibrinogen solutions using the enzymatic activity of thrombin. The process takes 2 days to complete, including an overnight dialysis step for the fibrinogen solution to remove citrates that inhibit polymerization. These detailed methods rely on fibrinogen concentrations determined to be optimal for embryonic and induced pluripotent stem cell culture. Other groups have further investigated fibrin scaffolds for a wide range of cell types and applications - demonstrating the versatility of this approach 8-12.

This work details the preparation of 3D fibrin scaffolds for culturing and differentiating plutipotent stem cells. Such scaffolds can be used to screen the effects of various biological compounds on stem cell behavior as well as modified to contain drug delivery systems.

Preparação de fibrina Andaimes 3D para aplicações de cultura de células-tronco

Stem cells are found in naturally occurring 3D microenvironments in vivo, which are often referred to as the stem cell niche 1. Culturing stem cells ...

Designing Silk-silk Protein Alloy Materials for Biomedical Applications

Fibrous proteins display different sequences and structures that have been used for various applications in biomedical fields such as biosensors, nanomedicine, tissue regeneration, and drug delivery. Designing materials based on the molecular-scale interactions between these proteins will help generate new multifunctional protein alloy biomaterials with tunable properties. Such alloy material systems also provide advantages in comparison to traditional synthetic polymers due to the materials biodegradability, biocompatibility, and tenability in the body. This article used the protein blends of wild tussah silk (Antheraea pernyi) and domestic mulberry silk (Bombyx mori) as an example to provide useful protocols regarding these topics, including how to predict protein-protein interactions by computational methods, how to produce protein alloy solutions, how to verify alloy systems by thermal analysis, and how to fabricate variable alloy materials including optical materials with diffraction gratings, electric materials with circuits coatings, and pharmaceutical materials for drug release and delivery. These methods can provide important information for designing the next generation multifunctional biomaterials based on different protein alloys.

Blending is an efficient approach to generate biomaterials with a broad range of properties and combined features. By predicting the molecular interactions between different natural silk proteins, new silk-silk protein alloy platforms with tunable mechanical resiliency, electrical response, optical transparency, chemical processability, biodegradability, or thermal stability can be designed.

Projetando proteína de seda-seda liga Materiais para aplicações biomédicas

Fibrous proteins display different sequences and structures that have been used for various applications in biomedical fields such as biosensors, ...

Fabrication of a Bioactive, PCL-based "Self-fitting" Shape Memory Polymer Scaffold

Tissue engineering has been explored as an alternative strategy for the treatment of critical-sized cranio-maxillofacial (CMF) bone defects. Essential to the success of this approach is a scaffold that is able to conformally fit within an irregular defect while also having the requisite biodegradability, pore interconnectivity and bioactivity. By nature of their shape recovery and fixity properties, shape memory polymer (SMP) scaffolds could achieve defect &#8220;self-fitting.&#8221; In this way, following exposure to warm saline (~60 &#186;C), the SMP scaffold would become malleable, permitting it to be hand-pressed into an irregular defect. Subsequent cooling (~37 &#186;C) would return the scaffold to its relatively rigid state within the defect. To meet these requirements, this protocol describes the preparation of SMP scaffolds prepared via the photochemical cure of biodegradable polycaprolactone diacrylate (PCL-DA) using a solvent-casting particulate-leaching (SCPL) method. A fused salt template is utilized to achieve pore interconnectivity. To realize bioactivity, a polydopamine coating is applied to the surface of the scaffold pore walls. Characterization of self-fitting and shape memory behaviors, pore interconnectivity and in vitro bioactivity are also described.

Fabrication of a Bioactive, PCL-based &quot;Self-fitting&quot; Shape Memory Polymer Scaffold

Scaffolds capable of fitting within cranio-maxillofacial (CMF) bone defects while exhibiting osteoconductivity and bioactivity are of interest. This protocol describes the preparation of a shape memory scaffold based on polycaprolactone diacrylate (PCL-DA) using a solvent-casting particulate-leaching (SCPL) method employing a fused salt template and application of a bioactive polydopamine coating.

Fabricação de uma baseada em PCL Bioativos, &quot;Self-fitting&quot; Memória de Forma Polymer Andaime

Tissue engineering has been explored as an alternative strategy for the treatment of critical-sized cranio-maxillofacial (CMF) bone defects. Essential to ...

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.

Fabricação de super-hidrofóbicas Materiais Poliméricos para aplicações biomédicas

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

Fabrication of a Dipole-assisted Solid Phase Extraction Microchip for Trace Metal Analysis in Water Samples

This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water samples. A brief overview of the evolution of chip-based SPE techniques is provided. This is followed by an introduction to specific polymeric materials and their role in SPE. To develop an innovative dipole-assisted SPE technique, a chlorine (Cl)-containing SPE functionality was implanted into a poly(methyl methacrylate) (PMMA) microchip. Herein, diverse analytical techniques including contact angle analysis, Raman spectroscopic analysis, and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis were employed to validate the utility of the implantation protocol of the C-Cl moieties on the PMMA. The analytical results of the X-ray absorption near-edge structure (XANES) analysis also demonstrated the feasibility of the Cl-containing PMMA used as an extraction medium by virtue of the dipole-ion interactions between the highly electronegative C-Cl moieties and the positively charged metal ions.

The fabrication protocol of a dipole-assisted solid phase extraction microchip for the trace metal analysis is presented.

Fabricação de um dipolo-assistida Fase Sólida Extração Microchip para análise de metais traço em amostras de água

This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water ...

Rapid Mix Preparation of Bioinspired Nanoscale Hydroxyapatite for Biomedical Applications

Hydroxyapatite (HA) has been widely used as a medical ceramic due to its good biocompatibility and osteoconductivity. Recently there has been interest regarding the use of bioinspired nanoscale hydroxyapatite (nHA). However, biological apatite is known to be calcium-deficient and carbonate-substituted with a nanoscale platelet-like morphology. Bioinspired nHA has the potential to stimulate optimal bone tissue regeneration due to its similarity to bone and tooth enamel mineral. Many of the methods currently used to fabricate nHA both in the laboratory and commercially, involve lengthy processes and complex equipment. Therefore, the aim of this study was to develop a rapid and reliable method to prepare high quality bioinspired nHA. The rapid mixing method developed was based upon an acid-base reaction involving calcium hydroxide and phosphoric acid. Briefly, a phosphoric acid solution was poured into a calcium hydroxide solution followed by stirring, washing and drying stages. Part of the batch was sintered at 1,000 &#176;C for 2 h in order to investigate the products&#39; high temperature stability. X-ray diffraction analysis showed the successful formation of HA, which showed thermal decomposition to &#946;-tricalcium phosphate after high temperature processing, which is typical for calcium-deficient HA. Fourier transform infrared spectroscopy showed the presence of carbonate groups in the precipitated product. The nHA particles had a low aspect ratio with approximate dimensions of 50 x 30 nm, close to the dimensions of biological apatite. The material was also calcium deficient with a Ca:P molar ratio of 1.63, which like biological apatite is lower than the stoichiometric HA ratio of 1.67. This new method is therefore a reliable and far more convenient process for the manufacture of bioinspired nHA, overcoming the need for lengthy titrations and complex equipment. The resulting bioinspired HA product is suitable for use in a wide variety of medical and consumer health applications.

This paper describes a novel method for the rapid manufacture of high quality bioinspired nanoscale hydroxyapatite. This biomaterial is of great significance in the manufacture of a wide range of innovative medical devices for clinical applications in orthopedics, craniofacial surgery and dentistry.

Rápido Mix Preparação de Bioinspirada Nanoscale hidroxiapatita para aplicações biomédicas

Hydroxyapatite (HA) has been widely used as a medical ceramic due to its good biocompatibility and osteoconductivity. Recently there has been interest ...

Patterning Bioactive Proteins or Peptides on Hydrogel Using Photochemistry for Biological Applications

There are many biological stimuli that can influence cell behavior and stem cell differentiation. General cell culture approaches rely on soluble factors within the medium to control cell behavior. However, soluble additions cannot mimic certain signaling motifs, such as matrix-bound growth factors, cell-cell signaling, and spatial biochemical cues, which are common influences on cells. Furthermore, biophysical properties of the matrix, such as substrate stiffness, play important roles in cell fate, which is not easily manipulated using conventional cell culturing practices. In this method, we describe a straightforward protocol to provide patterned bioactive proteins on synthetic polyethylene glycol (PEG) hydrogels using photochemistry. This platform allows for the independent control of substrate stiffness and spatial biochemical cues. These hydrogels can achieve a large range of physiologically relevant stiffness values. Additionally, the surfaces of these hydrogels can be photopatterned with bioactive peptides or proteins via thiol-ene click chemistry reactions. These methods have been optimized to retain protein function after surface immobilization. This is a versatile protocol that can be applied to any protein or peptide of interest to create a variety of patterns. Finally, cells seeded onto the surfaces of these bioactive hydrogels can be monitored over time as they respond to spatially specific signals.

In this method, we use photopolymerization and click chemistry techniques to create protein or peptide patterns on the surface of polyethylene glycol (PEG) hydrogels, providing immobilized bioactive signals for the study of cellular responses in vitro.

Padronização bioativas proteínas ou peptídeos em hidrogel usando fotoquímica para aplicações biológicas

There are many biological stimuli that can influence cell behavior and stem cell differentiation. General cell culture approaches rely on soluble factors ...

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.

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

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.

Derreter a eletrofiação escrita de andaimes Poly(ε-caprolactone) tridimensional com morfologias controláveis para aplicações de engenharia de tecidos

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

Fabrication and Characterization of Griffithsin-modified Fiber Scaffolds for Prevention of Sexually Transmitted Infections

Electrospun fibers (EFs) have been widely used in a variety of therapeutic applications; however, they have only recently been applied as a technology to prevent and treat sexually transmitted infections (STIs). Moreover, many EF technologies focus on encapsulating the active agent, relative to utilizing the surface to impart biofunctionality. Here we describe a method to fabricate and surface-modify poly(lactic-co-glycolic) acid (PLGA) electrospun fibers, with the potent antiviral lectin Griffithsin (GRFT). PLGA is an FDA-approved polymer that has been widely used in drug delivery due to its outstanding chemical and biocompatible properties. GRFT is a natural, potent, and safe lectin that possesses broad activity against numerous viruses including human immunodeficiency virus type 1 (HIV-1). When combined, GRFT-modified fibers have demonstrated potent inactivation of HIV-1 in vitro. This manuscript describes the methods to fabricate and characterize GRFT-modified EFs. First, PLGA is electrospun to create a fiber scaffold. Fibers are subsequently surface-modified with GRFT using 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS)chemistry. Scanning electron microscopy (SEM) was used to assess the size and morphology of surface-modified formulations. Additionally, a gp120 or hemagglutinin (HA)-based ELISA may be used to quantify the amount of GRFT conjugated to, as well as GRFT desorption from the fiber surface. This protocol can be more widely applied to fabricate fibers that are surface-modified with a variety of different proteins.

This manuscript describes the procedure to fabricate and characterize Griffithsin-modified poly(lactic-co-glycolic acid) electrospun fibers that demonstrate potent adhesive and antiviral activity against human immunodeficiency virus type 1 infection in vitro. Methods used to synthesize, surface-modify, and characterize the resulting morphology, conjugation, and desorption of Griffithsin from surface-modified fibers are described.

Fabricação e caracterização de andaimes de fibra Griffithsin-modificado para a prevenção de doenças sexualmente transmissíveis

Electrospun fibers (EFs) have been widely used in a variety of therapeutic applications; however, they have only recently been applied as a technology to ...