3D printed drug loaded nanomaterials for wound healing applications

Wounds are a stern healthcare concern in the growth of chronic disease conditions as they can increase healthcare costs and complicate internal and external health. Advancements in the current and newer management systems for wound healing should be in place to counter the health burden of wounds. Researchers discovered that two-dimensional (2D) media lacks appropriate real-life detection of cellular matter as these have highly complicated and diverse structures, compositions, and interactions. Hence, innovation towards three-dimensional (3D) media is called to conquer the high-level assessment and characterization in vivo using new technologies. The application of modern wound dressings prepared from a degenerated natural tissue, biodegradable biopolymer, synthetic polymer, or a composite of these materials in wound healing is currently an area of innovation in tissue regeneration medicine. Moreover, the integration of 3D printing and nanomaterial science is a promising approach with the potential for individualized, flexible, and precise technology for wound care approaches. This review encompasses the outcomes of various investigations on recent advances in 3D-printed drug-loaded natural, synthetic, and composite nanomaterials for wound healing. The challenges associated with their fabrication, clinical application progress, and future perspectives are also addressed.

[Research progress of antibacterial modification of orthopaedic implants surface]

OBJECTIVE

To summarize the related research progress of antibacterial modification of orthopaedic implants surface in recent years.

METHODS

The domestic and foreign related literature in recent years was extensively consulted, the research progress on antibacterial modification of orthopaedic implants surface was discussed from two aspects of characteristics of infection in orthopedic implants and surface anti-infection modification.

RESULTS

The orthopaedic implants infections are mainly related to aspects of bacterial adhesion, decreased host immunity, and surface biofilm formation. At present, the main antimicrobial coating methods of orthopaedic implants are antibacterial adhesion coating, antibiotic coating, inorganic antimicrobial coating, composite antimicrobial coating, nitric oxide coating, immunomodulation, three-dimensional printing, polymer antimicrobial coating, and "smart" coating.

CONCLUSION

The above-mentioned antibacterial coating methods of orthopedic implants can not only inhibit bacterial adhesion, but also solve the problems of low immunity and biofilm formation. However, its mechanism of action and modification are still controversial and require further research.

Tailoring nitric oxide release with additive manufacturing to create antimicrobial surfaces

The current use of implantable and indwelling medical is limited due to potential microbial colonization leading to severe ailments. The aim of this work is to develop bioactive polymers that can be customized based on patient needs and help prevent bacterial infection. Potential benefits of additive manufacturing technology are integrated with the antimicrobial properties of nitric oxide (NO) to develop NO-releasing biocompatible polymer interfaces for addressing bacterial infections. Using filament-based additive manufacturing and polycarbonateurethane-silicone (PCU-Sil) a range of films possessing unique porosities (Disk-60, Disk-40, solid, capped) were fabricated. The films were impregnated with S-nitroso-N-acetyl-penicillamine (SNAP) using a solvent-swelling process. The Disk-60 porous films had the greatest amount of SNAP (19.59 wt%) as measured by UV-vis spectroscopy. Scanning electron microscopy and energy-dispersive X-ray spectroscopy confirmed an even distribution of SNAP throughout the polymer. The films exhibited structure-based tunable NO-release at physiological levels ranging from 7-14 days for solid and porous films, as measured by chemiluminescence. The antibacterial efficacy of the films was studied against Staphylococcus aureus using 24 h in vitro bacterial adhesion assay. The results demonstrated a >99% reduction of viable bacteria on the surface of all the NO-releasing films compared to unmodified PCU-Sil controls. The combination of 3D-printing technology with NO-releasing properties represents a promising technique to develop customized medical devices (such as 3D-scaffolds, catheters, etc.) with distinct NO-release levels that can provide antimicrobial properties and enhanced biocompatibility.

New developments in anti-biofilm intervention towards effective management of orthopedic device related infections (ODRI's)

Orthopedic device related infections (ODRI's) represent a difficult to treat situation owing to their biofilm based nature. Biofilm infections once established are difficult to eradicate even with an aggressive treatment regimen due to their recalcitrance towards antibiotics and immune attack. The involvement of antibiotic resistant pathogens as the etiological agent further worsens the overall clinical picture, pressing on the need to look into alternative treatment strategies. The present review highlightes the microbiological challenges associated with treatment of ODRI's due to biofilm formation on the implant surface. Further, it details the newer anti-infective modalities that work either by preventing biofilm formation and/or through effective disruption of the mature biofilms formed on the medical implant. The study, therefore aims to provide a comprehensive insight into the newer anti-biofilm interventions (non-antibiotic approaches) and a better understanding of their mechanism of action essential for improved management of orthopedic implant infections.

Potential ecotoxicological effects of antimicrobial surface coatings: a literature survey backed up by analysis of market reports

This review was initiated by the COST action CA15114 AMICI "Anti-Microbial Coating Innovations to prevent infectious diseases," where one important aspect is to analyze ecotoxicological impacts of antimicrobial coatings (AMCs) to ensure their sustainable use. Scopus database was used to collect scientific literature on the types and uses of AMCs, while market reports were used to collect data on production volumes. Special attention was paid on data obtained for the release of the most prevalent ingredients of AMCs into the aqueous phase that was used as the proxy for their possible ecotoxicological effects. Based on the critical analysis of 2,720 papers, it can be concluded that silver-based AMCs are by far the most studied and used coatings followed by those based on titanium, copper, zinc, chitosan and quaternary ammonium compounds. The literature analysis pointed to biomedicine, followed by marine industry, construction industry (paints), food industry and textiles as the main fields of application of AMCs. The published data on ecotoxicological effects of AMCs was scarce, and also only a small number of the papers provided information on release of antimicrobial ingredients from AMCs. The available release data allowed to conclude that silver, copper and zinc are often released in substantial amounts (up to 100%) from the coatings to the aqueous environment. Chitosan and titanium were mostly not used as active released ingredients in AMCs, but rather as carriers for other release-based antimicrobial ingredients (e.g., conventional antibiotics). While minimizing the prevalence of healthcare-associated infections appeared to be the most prosperous field of AMCs application, the release of environmentally hazardous ingredients of AMCs into hospital wastewaters and thus, also the environmental risks associated with AMCs, comprise currently only a fraction of the release and risks of traditional disinfectants. However, being proactive, while the use of antimicrobial/antifouling coatings could currently pose ecotoxicological effects mainly in marine applications, the broad use of AMCs in other applications like medicine, food packaging and textiles should be postponed until reaching evidences on the (i) profound efficiency of these materials in controlling the spread of pathogenic microbes and (ii) safety of AMCs for the human and ecosystems.