Characterization of Sustained Release Electrospun Fibers That Target Porphyromonas gingivalis

Objectives: The interaction of P. gingivalis with streptococci contributes to colonization of the oral cavity by P. gingivalis. We identified a peptide (BAR) that inhibits this interaction but methods for prolonged delivery of the peptide in the oral cavity are lacking. The objective of this study was to determine if electrospun fibers (EFs) that encapsulate BAR function as a sustained release drug delivery vehicle for application in the oral cavity.

Methods: A variety of polymer formulations were electrospun using a uniaxial electrospinning approach. Polymers including poly(lactic-co-glycolic acid) (PLGA) or methoxy-poly(ethylene glycol) (mPEG-PLGA), polycaprolactone (PCL), and poly(L-lactic acid) PLLA, were synthesized alone or blended in a 40:60 and 20:80 w/w ratio with a hydrophilic polymer, polyethylene oxide (PEO). To determine the total loading of BAR in EFs, the fibers were dissolved in DMSO, and the amount of BAR encapsulated was compared to a known standard of fluorescently-labeled BAR (FBAR). The sustained-release of FBAR from fibers was determined by comparing the supernatant to a known standard of FBAR.
Results: PLGA, mPEG-PLGA and PLLA fibers demonstrated encapsulation efficiency of 68%, 94% and 46% respectively, while exhibiting 9%,7% and 1.5% release of BAR within 24 hr. Polymer blends in a 40:60 and 20:80 w/w ratio (PLGA:PEO; PCL:PEO; PLLA:PEO), similarly incorporated high concentrations of BAR peptide. Moreover, the polymer blends in 40:60 and 20:80 w/w ratio enhanced the release of BAR over 24 hr, ranging between 30%- 40% and 50%-80% respectively.

Conclusions: EFs comprised of polymer blends release higher amounts of BAR over 24 hr and may represent more effective drug delivery vehicles than PLGA, mPEG-PLGA or PLLA fibers.