Antibacterial Composite Materials Based on the Combination of Polyhydroxyalkanoates With Selenium and Strontium Co-substituted Hydroxyapatite for Bone Regeneration

Abstract

Due to the threat posed by the rapid growth in the resistance of microbial species to antibiotics, there is an urgent need to develop novel materials for biomedical applications capable of providing antibacterial properties without the use of such drugs. Bone healing represents one of the applications with the highest risk of postoperative infections, with potential serious complications in case of bacterial contaminations. Therefore, tissue engineering approaches aiming at the regeneration of bone tissue should be based on the use of materials possessing antibacterial properties alongside with biological and functional characteristics. In this study, we investigated the combination of polyhydroxyalkanoates (PHAs) with a novel antimicrobial hydroxyapatite (HA) containing selenium and strontium. Strontium was chosen for its well-known osteoinductive properties, while selenium is an emerging element investigated for its multi-functional activity as an antimicrobial and anticancer agent. Successful incorporation of such ions in the HA structure was obtained. Antibacterial activity against Staphylococcus aureus 6538P and Escherichia coli 8739 was confirmed for co-substituted HA in the powder form. Polymer-matrix composites based on two types of PHAs, P(3HB) and P(3HO-co-3HD-co-3HDD), were prepared by the incorporation of the developed antibacterial HA. An in-depth characterization of the composite materials was conducted to evaluate the effect of the filler on the physicochemical, thermal, and mechanical properties of the films. In vitro antibacterial testing showed that the composite samples induce a high reduction of the number of S. aureus 6538P and E. coli 8739 bacterial cells cultured on the surface of the materials. The films are also capable of releasing active ions which inhibited the growth of both Gram-positive and Gram-negative bacteria.

Special Features of Polyester-Based Materials for Medical Applications

“…The usual techniques for preparing modified polyesters for artificial bone-substitute materials involve 3D printing [ 51 , 61 , 65 , 66 , 72 , 74 , 75 , 76 ], thermally induced phase separation (TIPS) [ 32 ], salt leaching [ 32 , 69 , 79 ], solvent casting [ 33 , 35 , 77 , 79 ], electrospinning [ 60 , 64 , 70 ], copolymerization [ 31 ], and polycondensation [ 73 ].…”

Hyaluronic Acid-Based Nanomaterials as a New Approach to the Treatment and Prevention of Bacterial Infections

“…The microbial contamination of medical equipment caused by bacterial or fungal pathogens is an important factor in the transmission of nosocomial infections ( Francolini et al, 2015 ; Abed et al, 2022 ; Panahi et al, 2011 ; Rashki et al, 2021a ; Marzhoseyni et al, 2022 ; Mirzaei et al, 2020 ). Moreover, the alarming rise in antimicrobial-resistant species caused by the overuse of antibiotics now poses serious health and economic threat worldwide ( Marcello et al, 2021 ). Based, finding new materials with proper antibacterial landscapes as alternatives to antibiotics to combat bacterial infections has opened a novel field of research ( Abed et al, 2022 ; Marcello et al, 2021 ; Yazdanian et al, 2022 ; Lashkari and Ranjbar, 2021 ; Boroumand et al, 2021 ; Rashki et al, 2021b ; Khan et al, 2021 ).…”

“…Moreover, the alarming rise in antimicrobial-resistant species caused by the overuse of antibiotics now poses serious health and economic threat worldwide ( Marcello et al, 2021 ). Based, finding new materials with proper antibacterial landscapes as alternatives to antibiotics to combat bacterial infections has opened a novel field of research ( Abed et al, 2022 ; Marcello et al, 2021 ; Yazdanian et al, 2022 ; Lashkari and Ranjbar, 2021 ; Boroumand et al, 2021 ; Rashki et al, 2021b ; Khan et al, 2021 ). In this regard, cationic polymeric materials have attracted much interest, because of their intrinsic bactericidal activity and useful antibacterial effects ( Khoobi et al, 2020 ).…”

Antimicrobial Activity of Composites-Based on Biopolymers

“…In addition, the microbial organisms have somehow developed antibiotic microbial resistance (AMR). If not addressed, AMR will become a major global challenge as it constitutes a severe threat to global public health [6] and the economy [7]. Since the presence of harmful microorganisms is humanity's central concern nowadays, scientists are working hard to develop antimicrobial biocomposites [8].…”

“…The study and understanding of new composite materials with antibacterial features to inhibit bacterial growth and reduce bacterial adhesion is fundamental [7]. It is essential to understand how biofilms are formed to develop materials that can effectively kill microbes or inhibit microbial growth and biofilm formation [24].…”