Alternative strategies to reduce the incidence of severe infections
G.M. Vlasceanu1, A.M. Holban1,2, A.M. Grumezescu1
'University Politehnica of Bucharest, Bucharest, Romania; 2University of Bucharest,
The importance of biofilms in contracting or promoting severe human disease and the number of biofilm-associated conditions are constantly growing, being supported by the increasing number of implant-related nosocomial infections. Biofilms are difficult to define and also to eradicate since their structure and composition vary greatly from case to case; nonetheless, every microbial biofilm is a microecosystem consisting of microorganisms attached to a surface and embedded in an extracellular matrix consisting of polymeric molecules of microbial origin. Apart from the microbial organic compounds, the matrix could contain blood proteins, noncellular components such as mineralization centers (crystals), and corrosion-related particles (Percival et al., 2011).
Natural approaches for patient treatment, as well as green synthesis routes of antimicrobial nanoparticles, have raised awareness in the scientific communities since it was understood that often ecological strategies could be applied in drug and also material designs due to their undeniable advantages. To begin with, bioactive compounds could be easily extracted and since they manifest less toxicity, the safety of the receiving patient is enhanced and as a plus, the diversity of natural bioactive compounds allows the development of numerous strategies and wider applicability than standard chemical treatments.
Quorum sensing (QS) as therapeutic targets have emerged following the imperative need for novel treatment methods against violent and drug-resistant pathogens. The scientific community has been designing systems meant to disrupt the molecular pathways, which can allow cell-to-cell communication as a means to prevent and treat severe infections. Many approaches have been formulated with different results, as the mechanism is based, according to the nature of the pathogen and the nature of the bioactive substance on gene expression and various molecular modulators. There are still numerous drawbacks to this strategy, many related to superficial laboratory-scale investigations; nonetheless, the impact seems to be positive since the number of papers reporting significant results is increasing (Siddiqui et al., 2015).
New landmarks in the technological development can help ease the applicability of natural compounds and strategies in the fight against pathogens and can ensure the safest possible condition for the patients. With respect to this, superior hybrid approaches are ceaselessly outlined by researchers.
Biofilms and Implantable Medical Devices. http://dx.doi.org/10.1016/B978-0-08-100382-4.00009-5
Copyright © 2017 Elsevier Ltd. All rights reserved.
Artificial active compounds were not the first type of bioactive substances that humankind utilized to treat and prevent infections, but at the time of their first administrations, their effect had spectacularly positive outcomes. Although they were stronger, with a more radical behavior, some pathogenic strains adapted soon after administration and rendered these antimicrobial compounds rather useless. These circumstances determined the scientists to pursue the design of novel, more efficient structures and to use the contemporary technologies and available approaches to improve the strategies.
Biochemists and medical engineers struggle to discover and innovate convenient methods of synthesizing and administrating alternative synthetic or natural substances, which could lead to the development of personalized antimicrobial therapies.
Amino acids, peptides, proteins, polymers, and organic salts are, as illustrated, intensely studied, especially for the prevention and treatment of severe, biofilm-related and drug-resistant infections. However, it is yet difficult to address the medical community with the discovery of compounds close to the idea of a “gold standard” in antibacterial organic chemistry since the goal of balancing adequate cytotoxicity, availability, and costs has not been achieved yet.
Inorganic compounds, as anti-infectious agents, have the major advantage of a better plasticity as they are usually more stable than the organic bioactive substances. Smaller and diversified, with excellent possibilities of doping, conjugating, and combining in new superior and exciting composites, they encompass nanosilver, the most studied and used bactericidal material, whose behavior had been known and exploited for centuries.
The simple addition of some inorganic salts or ions or their conjugation or administration as doping agents can ensure or enhance the antimicrobial properties needed to prevent infections associated with scaffolding, wound dressing treatments, or device implantation. Often they are associated to standard antibiotics and/or other drugs with antipathogenic activity, either through simple physical mixture or through chemical conjugation (Pallavicini et al., 2014).
Nanobiomaterials as active antipathogenic agents may have important advantages. First of all, they may be utilized without functionalization, doping, or mixing with antimicrobial agents since they may exhibit antimicrobial properties on their own. Moreover, most nanomaterials designed for medical purpose perfectly integrate in the human body due to their biocompatibility and very low cytotoxic effects.
Thus, in this paper we intended to review and discuss diverse materials of various provenances that are being included in technologies aimed in the prevention and treatment of severe microbial infections in contemporary studies or already embedded in clinical use.