Surface modification of additively manufactured metallic biomaterials with active antipathogenic properties (original) (raw)
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ACS Biomaterials Science & Engineering, 2017
Additive manufacturing (AM) technologies enable greater geometrical design freedom compared with subtractive processes. This flexibility has been used to manufacture patient-matched implants. Although the advantages of AM are clear, the optimization at each process stage is often understated. Here we demonstrate that surface finishing of selective laser melted (SLM) implants significantly alters topography, which has implications for cellular and biofilm adhesion. Hot isostatic pressing of as-fabricated Ti-6Al-4V implants was shown to reduce porosity (1.04 to 0.02%) and surface roughness (34 ± 8 to 22 ± 3 μm). Despite these surface changes, preosteoblasts exhibited a similar viability and proliferation after 7 days of culture. Contrastingly, sandblasting and polishing significantly reduced cellular activity and increased cytotoxicity. Bacterial specimens (Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa) adhered more homogeneously to sandblasted implants compared with other treatments. This suggests that sandblasting may place the implant at risk of infection and reduce the strength of interaction with the surrounding soft tissues. The ability to tune the adhesion of cells to additively manufactured Ti-6Al-4V implants using postprocessing methods was demonstrated. Because the degree of tissue integration required of implants is application specific, these methods may be useful to tailor osseointegration. However, surface competition between mammalian and bacterial cells remains a challenge.
Preventing bacterial adhesion on scaffolds for bone tissue engineering
International Journal of Bioprinting, 2016
Bone implant infection constitutes a major sanitary concern which is associated to high morbidity and health costs. This manuscript focused on overviewing the main research efforts committed up to date to develop innovative alternatives to conventional treatments, such as those with antibiotics. These strategies mainly rely on chemical modifications of the surface of biomaterials, such as providing it of zwitterionic nature, and tailoring the nanostructure surface of metal implants. These surface modifications have successfully allowed inhibition of bacterial adhesion, which is the first step to implant infection, and preventing long-term biofilm formation compared to pristine materials. These strategies could be easily applied to provide three-dimensional (3D) scaffolds based on bioceramics and metals, of which its manufacture using rapid prototyping techniques was reviewed. This opens the gates for the design and development of advanced 3D scaffolds for bone tissue engineering to prevent bone implant infections.
Post Processing of 3D Printed Metal Scaffolds: a Preliminary Study of Antimicrobial Efficiency
Procedia Manufacturing, 2020
Additive manufacturing techniques enable users to produce complex devices that would not be possible by conventional methods, offering unique advantages to the medical industry due to the possibility to customize devices to accurately fit patient geometries. The process as done today needs still to be optimized in many aspects to achieve implants which better meet the requirements of the end application. Both the surface and the mechanical properties of the implant device have to better mimic the properties of the anatomical region of interest to assure a good interconnection with the surrounding tissue and the development of a strong interface. In the case of complex implants, the geometric accuracy of the replacing device is not the only factor with regard to the specific patient need. An optimal surface treatment after the manufacturing process can lead to a highly improved interaction of the implant with the surrounding physiological tissue. The improved outcome will be beneficial for the patient recovery process after the operation. This work goal is to provide an optimization of the post processing process of 3D printed titanium implants and the improvement of their performances, by a better and shorter assimilation of the implant to achieve the optimal patient wellness. In particular, the paper aims at the preliminary identification of the proper surface treatments that can lead to an implant that promotes the reduction of the bacterial adhesion to allow a better osseointegration in a long-term period. Ti6Al4V samples have been produced by a Selective Laser Melting (SLM) machine and the as-built surfaces have been treated in order to analyze the effects of post-processing on the surface and antimicrobial properties of the 3D printed specimens.
Applied Microbiology and Biotechnology, 2012
Biomaterials play a fundamental role in disease management and the improvement of health care. In recent years, there has been a significant growth in the diversity, function, and number of biomaterials used worldwide. Yet, attachment of pathogenic microorganisms onto biomaterial surfaces remains a significant challenge that substantially undermines their clinical applicability, limiting the advancement of these systems. The emergence and escalating pervasiveness of antibiotic-resistant bacterial strains makes the management of biomaterial-associated nosocomial infections increasingly difficult. The conventional post-operative treatment of implant-caused infections using systemic antibiotics is often marginally effective, further accelerating the extent of antimicrobial resistance. Methods by which the initial stages of bacterial attachment and biofilm formation can be restricted or prevented are therefore sought. The surface modification of biomaterials has the potential to alleviate pathogenic biofouling, therefore preventing the need for conventional antibiotics to be applied.
Functionalized Antimicrobial Composite Thin Films Printing for Stainless Steel Implant Coatings
Molecules, 2016
In this work we try to address the large interest existing nowadays in the better understanding of the interaction between microbial biofilms and metallic implants. Our aimed was to identify a new preventive strategy to control drug release, biofilm formation and contamination of medical devices with microbes. The transfer and printing of novel bioactive glass-polymer-antibiotic composites by Matrix-Assisted Pulsed Laser Evaporation into uniform thin films onto 316 L stainless steel substrates of the type used in implants are reported. The targets were prepared by freezing in liquid nitrogen mixtures containing polymer and antibiotic reinforced with bioglass powder. The cryogenic targets were submitted to multipulse evaporation by irradiation with an UV KrF* (λ = 248 nm, τ FWHM ď 25 ns) excimer laser source. The prepared structures were analyzed by infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and profilometry, before and after immersion in physiological fluids. The bioactivity and the release of the antibiotic have been evaluated. We showed that the incorporated antibiotic underwent a gradually dissolution in physiological fluids thus supporting a high local treatment efficiency. Electrochemical measurements including linear sweep voltammetry and impedance spectroscopy studies were carried out to investigate the corrosion resistance of the coatings in physiological environments. The in vitro biocompatibility assay using the MG63 mammalian cell line revealed that the obtained nanostructured composite films are non-cytotoxic. The antimicrobial effect of the coatings was tested against Staphylococcus aureus and Escherichia coli strains, usually present in implant-associated infections. An anti-biofilm activity was evidenced, stronger against E. coli than the S. aureus strain. The results proved that the applied method allows for the fabrication of implantable biomaterials which shield metal ion release and possess increased biocompatibility and resistance to microbial colonization and biofilm growth.
Antibacterial Surfaces for Biomedical Applications
2020
Medical devices such as orthopedic implants are intended to serve for improved quality of life. However, clinical success cannot be taken for granted and the most common reason for failure is due to biomaterials associated infection (BAI). An implantation surgical site is a susceptible environment for bacterial colonization, which in combination with compromised immune system, results in that bacteria can develop biofilms on the implant surface or in adjacent tissue. Once such a biofilm has established, it may lead to an infection that cannot be eradicated by means of traditional antibiotics, often resulting in revision surgery. Wounds after post implantation surgery is another risk for bacterial colonization into underlying tissue and increases further the susceptibility to infection. These and other bacteria related complications are today becoming more serious due to the rapid increase of antibiotic resistance worldwide. This has resulted in that many available antibiotics are lo...
Surgical Applications of Materials Engineered with Antimicrobial Properties
Bioengineering
The infection of surgically placed implants is a problem that is both large in magnitude and that broadly affects nearly all surgical specialties. Implant-associated infections deleteriously affect patient quality-of-life and can lead to greater morbidity, mortality, and cost to the health care system. The impact of this problem has prompted extensive pre-clinical and clinical investigation into decreasing implant infection rates. More recently, antimicrobial approaches that modify or treat the implant directly have been of great interest. These approaches include antibacterial implant coatings (antifouling materials, antibiotics, metal ions, and antimicrobial peptides), antibacterial nanostructured implant surfaces, and antibiotic-releasing implants. This review provides a compendium of these approaches and the clinical applications and outcomes. In general, implant-specific modalities for reducing infections have been effective; however, most applications remain in the preclinical...
The Impact of Incorporating Antimicrobials into Implant Surfaces
Journal of Dental Research, 2017
With the increase in numbers of joint replacements, spinal surgeries, and dental implantations, there is an urgent need to combat implant-associated infection. In addition to stringent sterile techniques, an efficacious way to prevent this destructive complication is to create new implants with antimicrobial properties. Specifically, these implants must be active in the dental implant environment where the implant is bathed in the glycoprotein-rich salivary fluids that enhance bacterial adhesion, and propagation, and biofilm formation. However, in designing an antimicrobial surface, a balance must be struck between antimicrobial activity and the need for the implant to interact with the bone environment. Three types of surfaces have been designed to combat biofilm formation, while attempting to maintain osseous interactions: 1) structured surfaces where topography, usually at the nanoscale, decreases bacterial adhesion sufficiently to retard establishment of infection; 2) surfaces t...
Metallic Antibacterial Surface Treatments of Dental and Orthopedic Materials
Materials, 2020
The oral cavity harbors complex microbial communities, which leads to biomaterial-associated infections (BAI) during dental and orthopedic treatments. Conventional antibiotic treatments have met great challenges recently due to the increasing emergency of drug-resistant bacteria. To tackle this clinical issue, antibacterial surface treatments, containing surface modification and coatings, of dental and orthopedic materials have become an area of intensive interest now. Among various antibacterial agents used in surface treatments, metallic agents possess unique properties, mainly including broad-spectrum antibacterial properties, low potential to develop bacterial resistance, relative biocompatibility, and chemical stability. Therefore, this review mainly focuses on underlying antibacterial applications and the mechanisms of metallic agents in dentistry and orthopedics. An overview of the present review indicates that much work remains to be done to deepen the understanding of antib...