Peptide KSL-W-Loaded Mucoadhesive Liquid Crystalline Vehicle as an Alternative Treatment for Multispecies Oral Biofilm

Abstract

Decapeptide KSL-W shows antibacterial activities and can be used in the oral cavity, however, it is easily degraded in aqueous solution and eliminated. Therefore, we aimed to develop liquid crystalline systems (F1 and F2) for KSL-W buccal administration to treat multispecies oral biofilms. The systems were prepared with oleic acid, polyoxypropylene (5) polyoxyethylene (20) cetyl alcohol (PPG-5-CETETH-20), and a 1% poloxamer 407 dispersion as the oil phase (OP), surfactant (S), and aqueous phase (AP), respectively. We characterized them using polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), rheology, and in vitro bioadhesion, and performed in vitro biological analysis. PLM showed isotropy (F1) or anisotropy with lamellar mesophases (F2), confirmed by peak ratio quantification using SAXS. Rheological tests demonstrated that F1 exhibited Newtonian behavior but not F2, which showed a structured AP concentration-dependent system. Bioadhesion studies revealed an AP concentration-dependent increase in the system's bioadhesiveness (F2 = 15.50 ± 1.00 mN·s) to bovine teeth blocks. Antimicrobial testing revealed 100% inhibition of multispecies oral biofilm growth after KSL-W administration, which was incorporated in the F2 aqueous phase at a concentration of 1 mg/mL. Our results suggest that this system could serve as a potential vehicle for buccal administration of antibiofilm peptides.

Keywords: KSL-W; antimicrobial peptide; biofilm; liquid crystalline systems; oral cavity.

Figure 1

Liquid crystalline system (LCS) mesophases.

Figure 2

Ternary phase diagram of PPG-5-CETETH-20 (surfactant) with oleic acid (oil phase) and poloxamer 407 aqueous dispersion (1%). ME, microemulsion; LC, liquid crystal; EM, emulsion; PS, phase separation; PRO, PPG-5-CETETH-20 (Procetyl^®); P407 1%, poloxamer 407 dispersion 1%; OA, oleic acid.

Figure 3

Photomicrographs obtained using polarized light microscopy (PLM) showing isotropy of microemulsion (F1) and Maltese cross of lamellar phase (F2).

Figure 4

Small-angle X-ray scattering (SAXS) patterns of samples F1 and F2 without KSL-W. Data were collected at 25 °C.

Figure 5

Rheograms of systems composed of poloxamer 407 dispersion (1%), oleic acid, and PPG-5-CETETH-20. Closed and open symbols indicate going and return, respectively. Data were collected at 37 °C.

Figure 6

Frequency sweep profile of storage and loss moduli G’ and G” (closed and opened and symbols), respectively, of systems composed of poloxamer 407 dispersion (1%), oleic acid, and PPG-5-CETETH-20. Data were collected at 37 ± 0.5 °C.

Figure 7

Parameters of in vitro bioadhesion test of systems composed of poloxamer 407 dispersion (1%), oleic acid, and PPG-5-CETETH-20. Data were collected at 37 ± 1°C and values represent mean ± standard deviation (SD) of seven replicates.