100 research outputs found
Rapidly Biodegrading PLGA-Polyurethane Fibers for Sustained Release of Physicochemically Diverse Drugs
Sustained
release of physicochemically diverse drugs from electrospun
fibers remains a challenge and precludes the use of fibers in many
medical applications. Here, we synthesize a new class of polyurethanes
with polyÂ(lactic-co-glycolic acid) (PLGA) moieties that degrade faster
than polyurethanes based on polycaprolactone. The new polymers, with
varying hard to soft segment ratios and fluorobenzene pendant group
content, were electrospun into nanofibers and loaded with four physicochemically
diverse small molecule drugs. Polymers were characterized using GPC,
XPS, and <sup>19</sup>F NMR. The size and morphology of electrospun
fibers were visualized using SEM, and drug/polymer compatibility and
drug crystallinity were evaluated using DSC. We measured <i>in
vitro</i> drug release, polymer degradation and cell-culture
cytotoxicity of biodegradation products. We show that these newly
synthesized PLGA-based polyurethanes degrade up to 65–80% within
4 weeks and are cytocompatible <i>in vitro</i>. The drug-loaded
electrospun fibers were amorphous solid dispersions. We found that
increasing the hard to soft segment ratio of the polymer enhances
the sustained release of positively charged drugs, whereas increasing
the fluorobenzene pendant content caused more rapid release of some
drugs. In summary, increasing the hard segment or fluorobenzene pendant
content of segmented polyurethanes containing PLGA moieties allows
for modulation of physicochemically diverse drug release from electrospun
fibers while maintaining a biologically relevant biodegradation rate
Azido Homoalanine is a Useful Infrared Probe for Monitoring Local Electrostatistics and Side-Chain Solvation in Proteins
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