Lavin DM, Stefani RM, Zhang L, Furtado S, Hopkins RA, Mathiowitz E. Multifunctional polymeric microfibers with prolonged drug delivery and structural support capabilities.
Acta Biomater 2012;
8:1891-900. [PMID:
22326788 DOI:
10.1016/j.actbio.2012.01.019]
[Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 01/17/2012] [Accepted: 01/17/2012] [Indexed: 11/25/2022]
Abstract
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 64±7 μm 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.
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