design-biaxial-mechanical-loading-bioreactor-for-tissue

Design of a Biaxial Mechanical Loading Bioreactor for Tissue Engineering

We  designed a loading device that is capable of applying uniaxial or biaxial  mechanical strain to a tissue engineered biocomposites fabricated for  ...

The Warren Alpert Brown Medical School of Brown University and the Rhode Island Hospital

La solidit&eacute; et la stabilit&eacute; des syst&egrave;mes d&#39;administration de fibre hybride, ceux qui remplissent une fonction m&eacute;canique et en m&ecirc;me temps livrer des m&eacute;dicaments, sont essentiels dans la conception de constructions chirurgicalement implantables. Nous rapportons la fabrication des microfibres &agrave; &eacute;lution de m&eacute;dicaments o&ugrave; le chargement de drogue et le traitement des conditions seules augmentent microfibre force et stabilit&eacute; partiellement en raison de la cristallisation induite par le solvant. Poly (acide L-lactique) microfibres de 64&plusmn;7 &mu;m de diam&egrave;tre &eacute;taient mouill&eacute;s fil&eacute; par inversion de phase. Encapsulation d&#39;un m&eacute;dicament anti-inflammatoire hydrophobe de mod&egrave;le, dexam&eacute;thasone, &agrave; forte charge apporter stabilit&eacute; &agrave; microfibres qui maintenues cin&eacute;tique lin&eacute;aire rejets cumulatifs jusqu&#39;&agrave; 8 semaines in vitro. Dans notre processus de filage humide, toutes les microfibres atteignait cristallinit&eacute; (13-17 %) par rapport aux polym&egrave;res non transform&eacute;s sans n&#39;importe quel &eacute;tirement m&eacute;canique. En outre, microfibres avec le chargement de drogue plu retenu 97 % de r&eacute;sistance &agrave; la rupture initiale et &eacute;taient statistiquement plus fort que tous les autres formulations de microfibre, y compris les fibres t&eacute;moins sans drogue. Les r&eacute;sultats indiquent que l&#39;encapsulation de petites mol&eacute;cules hydrophobes (&lt; 400 Da) peut augmenter l&#39;int&eacute;grit&eacute; m&eacute;canique de microfilaments dont cristallinit&eacute; est &eacute;galement augment&eacute;e par suite du processus. Multifonctionnel &agrave; &eacute;lution m&eacute;dicamenteuse microfibres peuvent fournir une opportunit&eacute; nouvelle de concevoir de nouveaux biomat&eacute;riaux avec stabilit&eacute; m&eacute;canique et la lib&eacute;ration d&#39;une vari&eacute;t&eacute; d&#39;agents th&eacute;rapeutiques de contr&ocirc;l&eacute;e avec pr&eacute;cision &agrave; l&#39;&eacute;chelle du micron.

Multifonctionnel microfibres polym&eacute;rique avec administration prolong&eacute;e de m&eacute;dicaments et des capacit&eacute;s de soutien structurel.

The strength and stability of hybrid fiber delivery systems, ones that perform a mechanical function and simultaneously deliver drug, are critical in the design of surgically implantable constructs. We report the fabrication of drug-eluting microfibers where drug loading and processing conditions alone increase microfiber strength and stability partially due to solvent-induced crystallization. Poly(L-lactic acid) microfibers of 64Â±7 Î¼m diameter were wet spun by phase inversion. Encapsulation of a model hydrophobic anti-inflammatory drug, dexamethasone, at high loading provided stability to microfibers which maintained linear cumulative release kinetics up to 8 weeks in vitro. In our wet spinning process, all microfibers had increased crystallinity (13-17%) in comparison to unprocessed polymer without any mechanical stretching. Moreover, microfibers with the highest drug loading retained 97% of initial tensile strength and were statistically stronger than all other microfiber formulations, including control fibers without drug. Results indicate that the encapsulation of small hydrophobic molecules (<400 Da) may increase the mechanical integrity of microfilaments whose crystallinity is also increased as a result of the process. Multifunctional drug-eluting microfibers can provide an exciting new opportunity to design novel biomaterials with mechanical stability and controlled release of a variety of therapeutics with micron-scale accuracy.

Multifunctional polymeric microfibers with prolonged drug delivery and structural support capabilities.

La forza e la stabilit&agrave; dei sistemi ibridi fibra consegna, quelli che svolgono una funzione meccanica e contemporaneamente fornire droga, sono fondamentali per la progettazione di costrutti impiantabili chirurgicamente. Riportiamo la fabbricazione di microfibre medicati dove carico di droga e l&#39;elaborazione di condizioni solo aumentare la forza in microfibra e stabilit&agrave; parzialmente a causa della cristallizzazione indotta da solvente. Microfibre di poli (acido L-lattico) di 64&plusmn;7 &mu;m di diametro sono stati bagnati filata da inversione di fase. Incapsulamento di un modello idrofobe farmaci anti-infiammatori, desametasone, a carico elevato fornito stabilit&agrave; di microfibre che mantenuto cinetica di rilascio cumulativo lineare fino a 8 settimane in vitro. Nel nostro processo di filatura bagnata, microfibre tutti avevano aumentato cristallinit&agrave; (13-17%) rispetto al polimero non trasformato senza alcun allungamento meccanico. Inoltre, microfibre con il pi&ugrave; alto carico di droga mantenne il 97% della resistenza alla trazione iniziale ed erano statisticamente pi&ugrave; forte di tutte le altre formulazioni di microfibra, tra cui controllo fibre senza droga. I risultati indicano che l&#39;incapsulamento di piccole molecole idrofobiche (&lt; Da 400) pu&ograve; aumentare l&#39;integrit&agrave; meccanica dei microfilamenti cui cristallinit&agrave; &egrave; aumentata anche a causa del processo. Microfibre medicati multifunzionale in grado di fornire un&#39;eccitante nuova opportunit&agrave; per la progettazione di nuovi biomateriali con stabilit&agrave; meccanica e il rilascio di una variet&agrave; di terapie controllato con precisione micron-scala.

Robert Stefani

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