Large-scale and highly efficient synthesis of micro- and nano-fibers with controlled fiber morphology by centrifugal jet spinning for tissue regeneration
Large-scale and highly efficient synthesis of micro- and nano-fibers with controlled fiber morphology by centrifugal jet spinning for tissue regeneration
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DOI：
10.1039/c3nr33423f
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发表时间：
2013-01-01
期刊：
影响因子：
6.7
通讯作者：
Kotha, Shiva P.
中科院分区：
文献类型：
--
作者：
Ren, Liyun;Pandit, Vaibhav;Kotha, Shiva P.
采用新型离心喷射纺丝工艺制备了具有可控纤维纳米级表面粗糙度的聚乳酸纤维组织支架。离心喷射纺丝技术是一种高效的微米至纳米级纤维的合成方法，其生产速率高达0.5 g min（-1）。在离心喷射纺丝过程中，聚合物溶液射流被旋转室的离心力拉伸。通过控制聚合物溶液的流变特性、溶剂蒸发速率和施加在溶液射流上的离心力，制备了不同直径的聚乙烯吡咯烷酮（PVP）和聚（L-乳酸）（PLLA）复合纤维。聚合物溶液的粘度测量使我们能够确定关键的聚合物链缠结极限，该极限允许产生连续纤维，而不是珠或珠状纤维。在聚合物链部分或完全缠结的临界浓度以上，较低的聚合物浓度和较高的离心力导致较细的纤维。随着PVP浓度的增加，PLLA-PVP复合纤维中PVP的刻蚀得到的PLLA纤维具有纳米级的表面粗糙度和孔隙率，从而显著提高了纤维的亲水性。蚀刻的复合纤维的扫描电子显微照片表明，PVP和PLLA共连续相分离的复合纤维在纺丝和纳米级的粗糙度功能后，部分蚀刻的PVP创建。为了研究工程化聚乳酸纤维基质的组织再生效果，使用人真皮成纤维细胞模拟部分皮肤移植。具有增加的PLLA表面粗糙度和孔隙率的纤维表现出更高的细胞附着和增殖的趋势。
PLLA fibrous tissue scaffolds with controlled fiber nanoscale surface roughness are fabricated with a novel centrifugal jet spinning process. The centrifugal jet spinning technique is a highly efficient synthesis method for micron-to nano-sized fibers with a production rate up to 0.5 g min(-1). During the centrifugal jet spinning process, a polymer solution jet is stretched by the centrifugal force of a rotating chamber. By engineering the rheological properties of the polymer solution, solvent evaporation rate and centrifugal force that are applied on the solution jet, polyvinylpyrrolidone (PVP) and poly(L-lactic acid) (PLLA) composite fibers with various diameters are fabricated. Viscosity measurements of polymer solutions allowed us to determine critical polymer chain entanglement limits that allow the generation of continuous fiber as opposed to beads or beaded fibers. Above a critical concentration at which polymer chains are partially or fully entangled, lower polymer concentrations and higher centrifugal forces resulted in thinner fibers. Etching of PVP from the PLLA-PVP composite fibers doped with increasing PVP concentrations yielded PLLA fibers with increasing nano-scale surface roughness and porosity, which increased the fiber hydrophilicity dramatically. Scanning electron micrographs of the etched composite fibers suggest that PVP and PLLA were co-contiguously phase separated within the composite fibers during spinning and nano-scale roughness features were created after the partial etching of PVP. To study the tissue regeneration efficacy of the engineered PLLA fiber matrix, human dermal fibroblasts are used to simulate partial skin graft. Fibers with increased PLLA surface roughness and porosity demonstrated a trend towards higher cell attachment and proliferation.