Bacterial and Candida albicans adhesion on rapid prototyping‐produced 3D‐scaffolds manufactured as bone replacement materials

Abstract

Rapid prototyping (RP)-produced scaffolds are gaining increasing importance in scaffold-guided tissue engineering. Microbial adhesion on the surface of replacement materials has a strong influence on healing and long-term outcome. Consequently, it is important to examine the adherence of microorganisms on RP-produced scaffolds. This research focussed on manufacturing of scaffolds by 3D-bioplotting and examination of their microbial adhesion characteristics. Tricalciumphosphate (TCP), calcium/sodium alginate, and poly(lactide-co-glycolic acid) (PLGA) constructs were produced and used to study the adhesion of dental pathogens. Six oral bacterial strains, one Candida strain and human saliva were used for the adhesion studies. The number of colony forming units (CFU) were determined and scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were performed. Microorganisms adhered to all scaffolds. All strains, except for Streptococcus oralis, adhered best to PLGA scaffolds. Streptococcus oralis adhered to each of the biomaterials equally. Streptococcus mutans and Enterococcus faecalis adhered best to PLGA scaffolds, followed by alginate and TCP. Prevotella nigrescens, Porphyromonas gingivalis, Streptococcus sanguis, and Candida albicans showed the highest adherence to PLGA, followed by TCP and alginate. In contrast, the microorganisms of saliva adhered significantly better to TCP, followed by PLGA and alginate. SEM observations correlated with the results of the CFU determinations. CLSM detected bacteria within deeper sheets of alginate. In conclusion, because of the high adherence rate of oral pathogens to the scaffolds, the application of these biomaterials for bone replacement in oral surgery could result in biomaterial-related infections. Strategies to decrease microbial adherence and to prevent infections due to oral pathogens are discussed.

Antiplaque Effect of Essential Oils and 0.2% Chlorhexidine on an In Situ Model of Oral Biofilm Growth: A Randomised Clinical Trial

“…The covering grade by the PL-Biofilm in combination with its thickness is directly related to the antiplaque capacity of an antiseptic agent. This parameter is important because it can be predictive of the adaptation of microorganisms to environmental influences [ 48 ]. To the best of author’s knowledge, there are no published papers on this issue in 4-day PL-Biofilm in situ .…”

Photodynamic therapy in the control of oral biofilms

“…PLGA nanoparticles loaded with various compounds (e.g. antibiotics) have been used for bacterial targeting (1, 57, 93, 97, 111, 156); however, the use of PLGA nanoparticles as carriers of photosensitizers has not been explored in antimicrobial photodynamic therapy until recently. In future, a more thorough evaluation of the photodynamic effects of methylene blue‐loaded nanoparticles would also require knowledge of various parameters that would lead to a maximum photodynamic effect on oral microbes, such as: the amount of methylene blue encapsulated in nanoparticles; the incubation time of methylene blue‐loaded nanoparticles with microorganisms; the power density (mW/cm 2 ); and the energy fluence (J/cm 2 ) of light.…”

Visualization of adherent micro-organisms using different techniques

“…This technique is also suitable for oral biofilms formed on enamel slabs, or for the visualization and calculation of the total bacterial count in comparison to the number of c.f.u. for bacteria which have adhered to biomaterials (Hannig et al, 2007b;Al-Ahmad et al, 2008b). However, no differentiation of bacterial species is possible with this simple technique.…”