Synthesis and characterization of sporopollenine-based biocomposite materials with biocidal activity against antibiotic-resistant microorganisms - SCABIOSA

Abstract

Antibiotic resistance is one of the biggest public health challenges of our time. Each year millions of people get an antibiotic‐resistant infection, and thousands of them die. Fighting this threat is a public health priority since new resistance mechanisms are emerging and spreading globally, threatening our ability to treat common infectious diseases, resulting in prolonged illness, disability, and even death.
Of special concern are wound infections with antimicrobial‐resistant bacteria, since such infection is a common problem in chronic wounds. Microorganisms resistant to antibiotics are one of the key reasons why wound healing may stall, which leads to increased risks of patient morbidity and mortality. Thus, research is needed on the develpmend and applicability of highly effective methods of treating chronic infected wounds in order to reduce the risk of antimicrobial resistance.
Big efforts are being made to develop antibacterial materials that can be used in daily life and protect the public health. Among these efforts, development of new biocomposite materials takes a special place since biocomposites are biodegradable and biocompatible materials generated from renewable biomass feedstock and are regarded as promising materials that could replace synthetic polymers. Thus, their development is driven also by concepts of sustainability, industrial ecology, eco‐efficiency, and green chemistry.
The objective of the proposed research project is the synthesis and characterization of novel biocomposite materials for wound dressings with biocidal activity against microorganisms resistant to antibiotics (e.g. bacteria such as E. coli, S. agalactiae, E. cloacae, P. aeruginosa, P. mirabilis S. maltophilia, methicillin‐resistant S. aureus (MRSA), and vancomycin‐resistant Enterococcus spp. (VRE) and fungi such as Candida albicans).
We aim to develop novel materials composed entirely of bioavailable and renewable natural materials, which shall provide adequate strength and structure to enable encapsulation of antibiotics, as well as desired porosity for faster wound healing. For this purpose, we will synthesize biocomposite materials based on cellulose (CEL), and keratin (KER) or chitosan (CS) with varying and controllable porosity and rate of drug release. This will be achieved by adding different amounts of sporopollenine, which will serve for immobilisation (microencapsulation) of antibiotics (Cyprofloxacin, Ceftriaxone, Amoxicillin, Gentamicin) and for improvement of the porosity of biocomposites, which is essential for proper diffusion of gases as well as drug release. Materials will be prepared by using concepts of green chemistry and an entirely recycleable process of synthesis, based on dissolution of CEL, KER or CS, and sporopollenine in ionic liquids. For the first time we intend to characterise biocomposite materials with antimicrobial activity by photothermal beam deflection spectrometry (BDS) to determine the porosity of synthesized materials and to enable optimisation of their synthesis, as well as properties. This will require further optimisation of BDS spectrometry and its validation by comparison against other existing methods and by measurements of materials with known porosities. Application of BDS will not be limited to determination of bulk properties only, but also to studies of subsurface structures and 3D distribution of materials’ properties (porosity, concentration of antibiotics), which are crucial for material’s strength and flexibility as well as for good antimicrobial activity and simultaneous oxygen access to the cured wound that is essential for effective function of the wound dressings and healing process.