Design and characterization of plasticized bacterial cellulose/waterborne polyurethane composite with antibacterial function for nasal stenting

Abstract

A nasal stent capable of preventing adhesions and inflammation is of great value in treating nasal diseases. In order to solve the problems of tissue adhesion and inflammation response, we prepared plasticized bacterial cellulose (BCG) and waterborne polyurethane (WPU) composite with antibacterial function used as a novel nasal stent. The gelation behavior of BCG could contribute to protecting the paranasal sinus mucosa; meanwhile, the WPU with improved mechanical property was aimed at supporting the narrow nasal cavity. The thickness, size and the supporting force of the nasal stent could be adjusted according to the specific conditions of the nasal. Thermogravimetric analysis, contact angle and water absorption test were applied to investigate the thermal, hydrophilic and water absorption properties of the composite materials. The composite materials loaded with poly(hexamethylene biguanide) hydrochloride maintained well antibacterial activity over 12 days. Animal experiments further revealed that the mucosal epithelium mucosae damage of BCG-WPU composite was minor compared with that of WPU. This new type of drug-loaded nasal stent can effectively address the postoperative adhesions and infections while ensuring the health of nasal mucosal, and thus has an immense clinical application prospects in treating nasal diseases.

Keywords: bacterial cellulose; biocompatibility; nasal stent; polyurethane.

Figure 1

Schematic representation of the design idea and the fabrication process of the BCG−WPU composite drug-loaded nasal stent

Figure 2

Surface and interface morphologies. (A) BC; (B) BC with WPU emulsion; (C) cross-section of BC−WPU; (D) BCG; (E) BCG with WPU emulsion; (F) cross-section of BCG−WPU; the upper right pictures of (C) and (F) were the contact angles of WPU emulsion on BC and BCG surfaces

Figure 3

(A) TGA curves of WPU, BC−WPU composite and BCG−WPU composite; (B) DTA curves of WPU, BC−WPU composite and BCG−WPU composite; (C) WCA of WPU, BC and BCG; (D) water absorption rate of WPU, BC−WPU composite and BCG−WPU composite

Figure 4

(A) Tensile stress−strain curves of BC and BCG (B); tensile stress−strain curves of BC−WPU, BCG−WPU and WPU; (C) the compression curves of BC−WPU, BCG−WPU and WPU at the same thickness; (D) the compression curves of BCG−WPU with different thickness; (E) Sinus model by MIMICS 3D reconstruction; (F) schematic diagram for the test of expansion supporting force; (G) the test samples of expansion supporting force

Figure 5

The inhibition zones (A) and their corresponding size (B) of the drug-loaded BCG-PU composite against S. aureus and E. coli; (C) OD values of BCG drug-loaded samples cultured with E. coli solution at different release time points; (D) OD value of WPU drug-loaded samples cultured with E. coli solution at different release time points; (E) OD values of control and experimental groups of L929s after 1, 3 and 7 days of culture; (F) the fluorescence images of living cells on BC, BCG and WPU at 1, 3 and 7 days of culture with Calcein-AM staining

Figure 6

The diagram of implantation process and anatomy after implantation for 3 and 7 days

Figure 7

The surfaces morphology of WPU and BCG−WPU composite before and after 3 and 7 days of implantation

Figure 8

Histologic staining of the inferior turbinate mucosa after the placement of WPU and BCG−WPU composite. Scale bar: 50 μm