The potential of nano graphene oxide and chlorhexidine composite membranes for use as a surface layer in functionally graded membranes for periodontal lesions

Abstract

Membranes have been used for treating periodontal defects and play a crucial role in guided bone regeneration applications. Nano graphene oxide have been exploited in tissue engineering due to its biomechanical properties. Its composite formulations with hydroxyapatite and chitosan with controlled degradation could aid in becoming part of a surface layer in a functionally graded membrane. The aim of the study was to synthesize chitosan and composite formulations of nano graphene oxide, hydroxyapatite and chlorhexidine digluconate using solvent casting technique and to characterize the physiochemical, mechanical, water vapor transmission rate (barrier), degradation and antimicrobial potential of the membranes. Altogether four different membranes were prepared (CH, CCG, 3511 and 3322). Results revealed the chemical interactions of hydroxyapatite, chitosan and nanographene oxide due to inter and intra molecular hydrogen bonding. The tensile strength of 3322 (33.72 ± 6.3 MPa) and 3511 (32.06 ± 5.4 MPa) was higher than CH (27.46 ± 9.6 MPa). CCG showed the lowest water vapor transmission rate (0.23 ± 0.01 g/h.m²) but the highest weight loss at day 14 (76.6 %). 3511 showed a higher drug release after 72 h (55.6 %) Significant biofilm growth inhibition was observed for all membranes. 3511 showed complete inhibition against A. actinomycetemcomitans. Detailed characterization of the synthesized membranes revealed that 3511 composite membrane proved to be a promising candidate for use as a surface layer of membranes for guided bone regeneration of periodontal lesions.

Fig. 1

Optical images and scanning electron micrographs of (A) CH (B), CCG (C), 3511 and (D) 3322. SEM images are shown at a magnification of 100X and 330X inset images of the membranes are shown at higher magnification. Optical images showing the color change and handling characteristics of the membranes. Images are scaled at 100 µm and inset image at 50 µm

Fig. 2

FTIR spectra (A) HA (B) GO (C) Prepared membranes neat CH, CCG, and composites 3511 and 3322. D The alterations in the fingerprint region. Peaks have been identified with their respective wavenumber numbers

Fig. 3

X ray photo electron spectroscopy data is shown in the form of Surveys of (A) CH, CCG, 3511 and 3322 (B) Carbon spectra of GO (C) Ca2p spectra of 3322, 3511 and CCG and (D) Nitrogen spectra of CH. More details of XPS spectra given in supplementary data

Fig. 4

Water uptake analysis conducted by Swelling ratio (%) for a period of 72 h on CH, CCG, 3351 and 3322. Values showed are mean ± SD, where (n = 3). * denotes statistically significant difference

Fig. 5

Degradation of the chitosan and composite membranes 3511, 3322 and CHC analyzed by (A)–(D) UV-vis spectroscopy at Day 4 (red), 7 (blue), 14 (green) and 21 (black) respectively (E) pH value change with time (F) Weight loss (%) analysis conducted over a period of 21 days. Specimens were analyzed on the Day, 4, 7, 14 and 21. Values of the pH and weight loss show mean ± SD

Fig. 6

Cumulative release of chlorhexidine digluconate from CH and composite membranes over a period of 72 h at 37 °C. Results are expressed as percentage release compared to the entrapped amount and means with their respective SD (n = 3). Statistically significance is denoted by, * = p 0.01, ** = p < 0.0001

Fig. 7

Antibacterial activity (A–D) and Quantitative RT-PCR results (E–H) of different membranes, CH, CCG, 3511 and 3322 on S. mutans, S. aureus, A. actinomycetemcomitans and P. gingivalis. Results represent the mean ± standard deviation of CFUs