Multifunctional polymeric microfibers with prolonged drug delivery and structural support capabilities.
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.
Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA.
Danya M
DM
Lavin
Robert M
RM
Stefani
Linda
L
Zhang
Stacia
S
Furtado
Richard A
RA
Hopkins
Edith
E
Mathiowitz
D000893:Anti-Inflammatory Agents / Q000737:chemistry; D002214:Capsules / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D003907:Dexamethasone / Q000737:chemistry*; D004058:Diffusion; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*
D000893:Anti-Inflammatory Agents; D002214:Capsules; D003692:Delayed-Action Preparations; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D003907:Dexamethasone