Mechanical, material, and antimicrobial properties of acrylic bone cement impregnated with silver nanoparticles

Enhancing orthopedic outcomes: A comparative analysis of gentamicin sulphate and nanosilver in bone cement

Background

Orthopedic surgeries frequently utilize bone cement, which can increase the risk of postoperative infections. Addressing this challenge, this study aims to enhance the mechanical, physical, and handling properties of bone cement by integrating gentamicin sulfate (GS) and nanosilver (nAg). The objective is to evaluate and compare the effects of these additives on properties such as compressive strength, flexural strength, doughing time, working time, setting time, and exothermic temperature. By doing so, the study seeks to identify a safer and more effective alternative to traditional antibiotics in bone cement formulations, thereby improving clinical outcomes in orthopedic procedures.

Methods

This research involved a comparative analysis of modified cements against standard cements, focusing on compressive strength, flexural strength, doughing time, working time, setting time, and exothermic temperature. Various bone cement samples with GS and nAg additives were prepared and tested in accordance with international standards (ISO 5833:2002 and ASTM F451). Statistical analysis, including one-way and two-way ANOVA tests, was used to assess the significance of the results.

Results

nAg-loaded cements exhibit mechanical and physical properties on par with or supe-rior to those of GS-loaded and standard cements. Notably, nAg incorporation leads to significantly lower exothermic temperatures, reducing the risk of thermal bone tissue damage. This finding highlights that nAg-loaded cement is a safer alternative. Alongside unaltered or enhanced strength, nAgs demonstrate promise for orthopedic applications, particularly in primary arthroplasty. Additionally, nAgs reduce doughing time, enhancing the practicality of these methods in surgical settings.

Conclusions

In conclusion, this study underscores the potential advantages of incorporating GSs and nAgs into bone cement. nAg-loaded cement offers improved properties and reduced infection risk, making it a valuable choice for orthopedic procedures. It enhances both mechanical performance and safety, addressing crucial concerns in orthopedic surgery.

The oral microbiota and periodontal health in orthodontic patients

The oral microbiota develops within the first 2 years of childhood and becomes distinct from the parents by 4 years-of-age. The oral microbiota plays an important role in the overall health/symbiosis of the individual. Deviations from the state of symbiosis leads to dysbiosis and an increased risk of pathogenicity. Deviations can occur not only from daily life activities but also from orthodontic interventions. Orthodontic appliances are formed from a variety of biomaterials. Once inserted, they serve as a breeding ground for microbial attachment, not only from new surface areas and crevices but also from material physicochemical interactions different than in the symbiotic state. Individuals undergoing orthodontic treatment show, compared with untreated people, qualitative and quantitative differences in activity within the oral microbiota, induced by increased retention of supra- and subgingival microbial plaque throughout the treatment period. These changes are at the root of the main undesirable effects, such as gingivitis, white spot lesions (WSL), and more severe caries lesions. Notably, the oral microbiota profile in the first weeks of orthodontic intervention might be a valuable indicator to predict and identify higher-risk individuals with respect to periodontal health and caries risk within an otherwise healthy population. Antimicrobial coatings have been used to dissuade microbes from adhering to the biomaterial; however, they disrupt the host microbiota, and several bacterial strains have become resistant. Smart biomaterials that can reduce the antimicrobial load preventing microbial adhesion to orthodontic appliances have shown promising results, but their complexity has kept many solutions from reaching the clinic. 3D printing technology provides opportunities for complex chemical syntheses to be performed uniformly, reducing the cost of producing smart biomaterials giving hope that they may reach the clinic in the near future. The purpose of this review is to emphasize the importance of the oral microbiota during orthodontic therapy and to use innovative technologies to better maintain its healthy balance during surgical procedures.

Graphene oxide-encapsulated baghdadite nanocomposite improved physical, mechanical, and biological properties of a vancomycin-loaded PMMA bone cement

Polymethyl methacrylate (PMMA) bone cement is commonly used in orthopedic surgeries to fill the bone defects or fix the prostheses. These cements are usually containing amounts of a nonbioactive radiopacifying agent such as barium sulfate and zirconium dioxide, which does not have a good interface compatibility with PMMA, and the clumps formed from these materials can scratch metal counterfaces. In this work, graphene oxide encapsulated baghdadite (GOBgh) nanoparticles were applied as radiopacifying and bioactive agent in a PMMA bone cement containing 2 wt.% of vancomycin (VAN). The addition of 20 wt.% of GOBgh (GOBgh20) nanoparticles to PMMA powder caused a 33.6% increase in compressive strength and a 70.9% increase in elastic modulus compared to the Simplex® P bone cement, and also enhanced the setting properties, radiopacity, antibacterial activity, and the apatite formation in simulated body fluid. In vitro cell assessments confirmed the increase in adhesion and proliferation of MG-63 cells as well as the osteogenic differentiation of human adipose-derived mesenchymal stem cells on the surface of PMMA-GOBgh20 cement. The chorioallantoic membrane assay revealed the excellent angiogenesis activity of nanocomposite cement samples. In vivo experiments on a rat model also demonstrated the mineralization and bone integration of PMMA-GOBgh20 cement within four weeks. Based on the promising results obtained, PMMA-GOBgh20 bone cement is suggested as an optimal sample for use in orthopedic surgeries.

Preparation and characterizations of antibacterial poly(methyl methacrylate) bone cement via copolymerization with a quaternary ammonium monomer of dimethylaminotriclosan methacrylate

Poly (methyl methacrylate) (PMMA) bone cement relies on the loaded antibiotic to realize the antibacterial purpose. But the exothermic behavior during setting often makes temperature-sensitive antibiotics inactivated. It is necessary to develop new material candidates to replace antibiotics. In this study, a new quaternary ammonium methacrylate (QAM) monomer called dimethylaminetriclosan methacrylate (DMATCM) was designed by the quaternization between 2-(Dimethylamino)ethyl methacrylate and triclosan, then employed as the modifier to explore the feasibility of equipping bone cement with antibacterial activity, and to investigate the variations on the physical and biological performances brought by the substitution ratio of DMATCM to MMA. Results showed that DMATCM opened its C=C bonding to participate in the MMA polymerization, and the quaternary ammonium group helped it to perform broad-spectrum antibacterial property against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. With an increased substitution ratio of DMATCM to MMA, the glass transition temperatures, the maximum exothermic temperatures, and the contact angles of bone cements declined, but the residual monomer contents, the fluid uptakes, and the setting times under Vical indentation increased. Long-term soaking made almost no changes to the weight loss and the mechanical properties of DMATCM-modified cements with lower substitution ratios of 0∼20%, and the activation rather enhanced the strengths of uncured AMBC-4 and AMBC-5 samples. Owing to more DMATCM exposed on the cement surface, the inhibition ring diameter produced by modified cement was improved to a maximum of 28.09 mm, and MC3T3-E1 cells performed the cell viabilities all beyond 70% and healthy adhesion after 72 h co-culturing. Taking all measured properties and ISO standards into account, the antibacterial bone cement under the ratio of 10% performed better, besides its good bactericidal effect, the other properties satisfied the requirements for clinical application.

Vancomycin Loaded Amino-Functionalized MCM-48 Mesoporous Silica Nanoparticles as a Promising Drug Carrier in Bone Substitutes for Bacterial Infection Management

Orthopedic infections due to biofilm formation in biomaterial-based implants have become challenging in bone tissue engineering. In the present study, in vitro antibacterial analysis of amino-functionalized MCM-48 mesoporous silica nanoparticles (AF-MSNs) loaded with vancomycin is analyzed for its potential as a drug carrier for the sustained/controlled release of vancomycin against Staphylococcus aureus. The effective incorporation of vancomycin into the inner core of AF-MSNs was observed by alternation in the absorption frequencies obtained by Fourier transform infrared spectroscopy (FTIR). Dynamic light scattering (DLS) and high resolution-transmission electron microscopy (HR-TEM) results show that all the AF-MSNs had homogeneous spherical shapes with a mean diameter of 165.2 ± 1.25 nm, and there is a slight change in the hydrodynamic diameter after vancomycin loading. Furthermore, the zeta potential of all the AF-MSNs (+ 30.5 ± 0.54 mV) and AF-MSN/VA (+ 33.3 ± 0.56 mV) were positively charged due to effective functionalization with 3-aminopropyl triethoxysilane (APTES). Furthermore, cytotoxicity results show that the AF-MSNs have better biocompatibility than non-functionalized MSNs (p < 0.05), and results prove AF-MSNs loaded with vancomycin show better antibacterial effect against S. aureus than non-functionalized MSNs. Results confirm that bacterial membrane integrity was affected by treatment with AF-MSNs and AF-MSN/VA by staining the treated cells with FDA/PI. Field emission scanning electron microscopy (FESEM) analysis confirmed the shrinkage of bacterial cells and membrane disintegration. Furthermore, these results demonstrate that amino-functionalized MSNs loaded with vancomycin significantly increased the anti-biofilm and biofilm inhibitory effect and can be incorporated with biomaterial-based bone substitutes and bone cement to prevent orthopedic infections post-implantation.

A Toolbox of Bone Consolidation for the Interventional Radiologist

Bone consolidation is increasingly used in the treatment of both benign and malignant bone conditions. Percutaneous vertebroplasty, for example, has been shown to be useful in vertebral compression fractures in the VAPOUR trial which showed its superiority to placebo for pain reduction in the treatment of acute vertebral compressive fractures. Further tools have since been developed, such as kyphoplasty, spinal implants, and even developments in bone cements itself in attempt to improve outcome, such as chemotherapy-loaded cement or cement replacements such as radio-opaque silicon polymer. More importantly, bone fixation and its combination with cement have been increasingly performed to improve outcome. Interventional radiologists must first know the tools available, before they can best plan for their patients. This review article will focus on the tool box available for the modern interventional radiologist.

A Triboelectric Nanocomposite for Sterile Sensing, Energy Harvesting, and Haptic Diagnostics in Interventional Procedures from Surgical Gloves

Advanced interfacial engineering has the potential to enable the successful realization of three features that are particularly important for a variety of healthcare applications: wettability control, antimicrobial activity to reduce infection risks, and sensing of physiological parameters. Here, a sprayable multifunctional triboelectric coating is exploited as a nontoxic, ultrathin tactile sensor that can be integrated directly on the fingertips of surgical gloves. The coating is based on a polymer blend mixed with zinc oxide (ZnO) nanoparticles, which enables antifouling and antibacterial properties. Additionally, the nanocomposite is superhydrophobic (self-cleaning) and is not cytotoxic. The coating is also triboelectric and can be applied directly onto surgical gloves with printed electrodes. The sensorized gloves so obtained enable mechanical energy harvesting, force sensing, and detection of materials stiffness changes directly from fingertip, which may complement proprioceptive feedback for clinicians. Just as importantly, the sensors also work with a second glove on top offering better reassurance regarding sterility in interventional procedures. As a case study of clinical use for stiffness detection, the sensors demonstrate successful detection of pig anal sphincter injury ex vivo. This may lead to improving the accuracy of diagnosing obstetric anal sphincter injury, resulting in prompt repair, fewer complications, and improved quality of life.

Physical, Mechanical, and Biological Properties of PMMA-Based Composite Bone Cement Containing Silver-Doped Bioactive and Antibacterial Glass Particles with Different Particles Sizes

In the present work, antibacterial composite bone cement was designed by introducing a bioactive and antibacterial glass into a commercial formulation. The effect of glass particles' addition on the curing parameters of the polymeric matrix was evaluated; moreover, the influence of the glass particle size on the glass dispersion, compressive and bending strength, bioactivity, and antibacterial effect was estimated. The results evidence a delay in the polymerization kinetics of the composite cement, which nevertheless complies with the requirements of the ISO standard. Morphological characterization provides evidence of good dispersion of the glass in the polymeric matrix and its exposition on the cement surface. The different glass grain sizes do not affect the composites' bioactivity and compressive strength, while a slight reduction in bending strength was observed for samples containing glass powders with greater dimensions. The size of the glass particles also appears to have an effect on the antibacterial properties, since the composites containing larger glass particles do not produce an inhibition halo towards the S. aureus strain. The obtained results demonstrate that, by carefully tailoring the glass amount and size, a multifunctional device for artificial joint fixing, temporary prostheses, or spinal surgery can be obtained.

Study on injectable silver-incorporated calcium phosphate composite with enhanced antibacterial and biomechanical properties for fighting bone cement-associated infections

Although commonly used in orthopedic surgery, bone cements often face a high risk of post-operative infection. Developing bone cement with antibacterial capability is an effective path for eliminating implant-associated infections. Herein, the potential of silver ions (Ag⁺) and silver nanoparticles (AgNPs) in modifying CPC for long-term antibacterial property was investigated. Ag⁺ ions or AgNPs of various concentrations were incorporated in starch-modified calcium phosphate bone cement (CPB) to obtain Ag⁺-containing (Ag⁺@CPB) and AgNPs-containing (AgNP@CPB) bone cements. The results showed that all silver-containing CPBs had setting times of about 25-40 min, compressive strengths of greater than 22 MPa, high cytocompatibility but inhibitory effect on Staphylococcus aureus growth. After soaking for 1 week, the mechanical properties and the cytocompatibility of all cements revealed no significant changes, but only CPB with a relatively high content of Ag⁺ (H-Ag⁺@CPB) maintained good antibacterial capability over the tested time period. In addition, all the cements showed high injectability and interdigitating capability in cancellous bone and demonstrated augmentation effect on the cannulated pedicle screws fixation in the Sawbones model. In summary, the sustainable antibacterial capability and enhanced biomechanical properties demonstrated that Ag⁺ ions were more suitable for the fabrication of antibacterial CPC compared to AgNPs. Also, the H-Ag⁺@CPB, with good injectability, high cytocompatibility, good interdigitating and biomechanical property in cancellous bone, and sustainable antibacterial effects, bears great potential for the treatments of bone infections or implant-associated infections.

Nanosilver/DCOIT-containing surface coating effectively and constantly reduces microbial load in emergency room surfaces

BACKGROUND

Colonization of near-patient surfaces in hospitals plays an important role as a source of healthcare-associated infections. Routine disinfection methods only result in short-term elimination of pathogens.

AIM

To investigate the efficiency of a newly developed antimicrobial coating containing nanosilver in long-term reduction of bacterial burden in hospital surfaces to close the gap between routine disinfection cycles.

METHODS

In this prospective, double-blinded trial, frequently touched surfaces of a routinely used treatment room in an emergency unit of a level-I hospital were treated with a surface coating (nanosilver/DCOIT-coated surface, NCS) containing nanosilver particles and another organic biocidal agent (4,5-dichloro-2-octyl-4-isothiazolin-3-one, DCOIT), whereas surfaces of another room were treated with a coating missing both the nanosilver- and DCOIT-containing ingredient and served as control. Bacterial contamination of the surfaces was examined using contact plates and liquid-based swabs daily for a total trial duration of 90 days. After incubation, total microbial counts and species were assessed.

FINDINGS

In a total of 2880 antimicrobial samples, a significant reduction of the overall bacterial load was observed in the NCS room (median: 0.31 cfu/cm²; interquartile range: 0.00-1.13) compared with the control coated surfaces (0.69 cfu/cm²; 0.06-2.00; P < 0.001). The nanosilver- and DCOIT-containing surface coating reduced the relative risk of a critical bacterial load (defined as >5 cfu/cm²) by 60% (odds ratio 0.38, P < 0.001). No significant difference in species distribution was detected between NCS and control group.

CONCLUSION

Nanosilver-/DCOIT-containing surface coating has shown efficiency for sustainable reduction of bacterial load of frequently touched surfaces in a clinical setting.

Silver Nanoparticles Enhance the Antibacterial Effect of Antibiotic-Loaded Bone Cement

Purpose The goal of this study was to determine the antibacterial activity of bone cement in polymethyl methacrylate (PMMA) structures with varying amounts of silver nanoparticles (AgNPs) included. Additionally, we aimed to evaluate whether AgNPs affect the biomechanical properties of PMMA cement in our study. Materials and methods Between April 2020 and June 2020, we conducted a series of experiments to demonstrate the antibacterial characteristics by adding silver nanoparticles to PMMA bone cement. PMMA bone cement (Cemex, Tecres Company, Verona, Italy) was used as the base material. Seven different samples were prepared in order to evaluate the amount and presence of AgNPs. Cement samples containing AgNPs and teicoplanin at different concentrations and empty cement (control, without teicoplanin and AgNPs) were placed on Petri plates. The agar diffusion method was used to determine the antibacterial effect (Kirby-Bauer). Results Kirby-Bauer assays demonstrated that AgNPs added to bone cement increased the antimicrobial activity compared to antibiotic-free or only teicoplanin-loaded cement. It was observed that increasing the AgNPs ratio further increased the antimicrobial activity. Conclusion AgNPs in various combinations enhance antimicrobial activity synergistically while maintaining the mechanical strength of bone cement. Increasing the amount of AgNPs results in a significant increase in antimicrobial activity.

Silver Nanoparticles: Bactericidal and Mechanistic Approach against Drug Resistant Pathogens

This review highlights the different modes of synthesizing silver nanoparticles (AgNPs) from their elemental state to particle format and their mechanism of action against multidrug-resistant and biofilm-forming bacterial pathogens. Various studies have demonstrated that the AgNPs cause oxidative stress, protein dysfunction, membrane disruption, and DNA damage in bacteria, ultimately leading to bacterial death. AgNPs have also been found to alter the adhesion of bacterial cells to prevent biofilm formation. The benefits of using AgNPs in medicine are, to some extent, counter-weighted by their toxic effect on humans and the environment. In this review, we have compiled recent studies demonstrating the antibacterial activity of AgNPs, and we are discussing the known mechanisms of action of AgNPs against bacterial pathogens. Ongoing clinical trials involving AgNPs are briefly presented. A particular focus is placed on the mechanism of interaction of AgNPs with bacterial biofilms, which are a significant pathogenicity determinant. A brief overview of the use of AgNPs in other medical applications (e.g., diagnostics, promotion of wound healing) and the non-medical sectors is presented. Finally, current drawbacks and limitations of AgNPs use in medicine are discussed, and perspectives for the improved future use of functionalized AgNPs in medical applications are presented.

A concise review on implications of silver nanoparticles in bone tissue engineering

Skeletal disorders represent a variety of degenerative diseases that affect bone and cartilage homeostasis. The regenerative capacity of bone is affected in osteoporosis, osteoarthritis, rheumatoid arthritis, bone fractures, congenital defects, and bone cancers. There is no viable, non-invasive treatment option and bone regeneration requires surgical intervention with the implantation of bone grafts. Incorporating nanoparticles in bone grafts have improved fracture healing by providing fine structures for bone tissue engineering. It is currently a revolutionary finding in the field of regenerative medicine. Silver nanoparticles (AgNPs) have garnered particular attention due to their well-known anti-microbial and potential osteoinductive properties. In addition, AgNPs have been demonstrated to regulate the proliferation and differentiation of mesenchymal stem cells (MSCs) involved in bone regeneration. Furthermore, AgNPs have shown toxicity towards cancer cells derived from bone. In the last decade, there have been multiple studies focusing on the effect of nanoparticles on the proliferation and/or differentiation of MSCs and bone cancer cells; however, the specific studies with AgNPs are limited. Although the reported investigations show promising in vitro and in vivo potential of AgNPs for application in bone regeneration, more studies are required to ensure their implications in bone tissue engineering. This review aims to highlight the current advances related to the production of AgNPs and their effect on MSCs and bone cancer cells, which will potentiate their possible implications in orthopedics. Moreover, this review article evaluates the future of AgNPs in bone tissue engineering.

Effect of the Antimicrobial Agents Peppermint Essential Oil and Silver Nanoparticles on Bone Cement Properties

The main problems directly linked with the use of PMMA bone cements in orthopedic surgery are the improper mechanical bond between cement and bone and the absence of antimicrobial properties. Recently, more research has been devoted to new bone cement with antimicrobial properties using mainly antibiotics or other innovative materials with antimicrobial properties. In this paper, we developed modified PMMA bone cement with antimicrobial properties proposing some experimental antimicrobial agents consisting of silver nanoparticles incorporated in ceramic glass and hydroxyapatite impregnated with peppermint oil. The impact of the addition of antimicrobial agents on the structure, mechanical properties, and biocompatibility of new PMMA bone cements was quantified. It has been shown that the addition of antimicrobial agents improves the flexural strength of the traditional PMMA bone cement, while the yield strength values show a decrease, most likely because this agent acts as a discontinuity inside the material rather than as a reinforcing agent. In the case of all samples, the addition of antimicrobial agents had no significant influence on the thermal stability. The new PMMA bone cement showed good biocompatibility and the possibility of osteoblast proliferation (MTT test) along with a low level of cytotoxicity (LDH test).

Mechanical Characterization of Dental Prostheses Manufactured with PMMA-Graphene Composites

The use of a PMMA composite with graphene is being commercialized for application as dental prostheses. The different proportions of fibers provide a wide range of colors that favors dental esthetics in prostheses. However, there are no studies that have explained the influence that graphene has on the mechanical properties. In this contribution, we studied the PMMA and PMMA material with graphene fibers (PMMA-G) in the form of discs as supplied for machining. The presence of graphene fibers has been studied by Raman spectroscopy and the Shore hardness and Vickers micro hardness were determined. Mechanical compression tests were carried out to obtain the values of maximum strength and Young’s modulus (E) and by means of pin-on-disc wear tests, the specific wear rate and the friction coefficients were determined following the established international standards. Finally, the samples were characterized by field emission scanning electron microscopy (FESEM) to characterize the graphene’s morphology inside the PMMA. The results showed the presence of graphene in PMMA and was estimated in an amount of 0.1027% by weight in G-PMMA. The Shore hardness and Vickers microhardness values did not show statistically significant differences. Differences were observed in the compression maximum strength (129.43 MPa for PMMA and 140.23 for PMMA-G) and E values (2.01 for PMMA and 2.89 GPa for PMMA-G) as well as in the lower wear rate for the G-PMMA samples (1.93 × 10−7 for PMMA and 1.33 × 10−7 mm3/N·m) with a p < 0.005. The coefficients of friction for PMMA-G decreased from 0.4032 for PMMA to 0.4001 for PMMA-G. From the results obtained, a slight content in graphene produced a significant improvement in the mechanical properties that could be observed in the prosthesis material. Therefore, we can state that the main attraction of this material for dental prosthesis is its esthetics.

Antibiotic-free antimicrobial poly (methyl methacrylate) bone cements: A state-of-the-art review

Prosthetic joint infection (PJI) is the most serious complication following total joint arthroplasty, this being because it is associated with, among other things, high morbidity and low quality of life, is difficult to prevent, and is very challenging to treat/manage. The many shortcomings of antibiotic-loaded poly (methyl methacrylate) (PMMA) bone cement (ALBC) as an agent for preventing and treating/managing PJI are well-known. One is that microorganisms responsible for most PJI cases, such as methicillin-resistant S. aureus, have developed or are developing resistance to gentamicin sulfate, which is the antibiotic in the vast majority of approved ALBC brands. This has led to many research efforts to develop cements that do not contain gentamicin (or, for that matter, any antibiotic) but demonstrate excellent antimicrobial efficacy. There is a sizeable body of literature on these so-called "antibiotic-free antimicrobial" PMMA bone cements (AFAMBCs). The present work is a comprehensive and critical review of this body. In addition to summaries of key trends in results of characterization studies of AFAMBCs, the attractive features and shortcomings of the literature are highlighted. Shortcomings provide motivation for future work, with some ideas being formulation of a new generation of AFAMBCs by, example, adding a nanostructured material and/or an extract from a natural product to the powder and/or liquid of the basis cement, respectively.

Influence of Different Nanometals Implemented in PMMA Bone Cement on Biological and Mechanical Properties

Cemented arthroplasty is a common process to fix prostheses when a patient becomes older and his/her bone quality deteriorates. The applied cements are biocompatible, can transfer loads, and dampen vibrations, but do not provide antibacterial protection. The present work is aimed at the development of cement with antibacterial effectivity achieved with the implementation of nanoparticles of different metals. The powders of Ag, Cu with particles size in a range of 10–30 nm (Cu10) and 70–100 nm (Cu70), AgCu, and Ni were added to PMMA cement. Their influence on compression strength, wettability, and antibacterial properties of cement was assessed. The surface topography of samples was examined with biological and scanning electron microscopy. The mechanical properties were determined by compression tests. A contact angle was observed with a goniometer. The biological tests included an assessment of cytotoxicity (XTT test on human cells Saos-2 line) and bacteria viability exposure (6 months). The cements with Ag and Cu nanopowders were free of bacteria. For AgCu and Ni nanoparticles, the bacterial solution became denser over time and, after 6 months, the bacteria clustered into conglomerates, creating a biofilm. All metal powders in their native form in direct contact reduce the number of eukaryotic cells. Cell viability is the least limited by Ag and Cu particles of smaller size. All samples demonstrated hydrophobic nature in the wettability test. The mechanical strength was not significantly affected by the additions of metal powders. The nanometal particles incorporated in PMMA-based bone cement can introduce long-term resistance against bacteria, not resulting in any serious deterioration of compression strength.

Preparation of new bio-based antibacterial acrylic bone cement via modification with a biofunctional monomer of nitrofurfuryl methacrylate

The new bio-based antibacterial p(NFMA-co-MMA) bone cement exhibits excellent antibacterial performance in the treatment of osteoporotic vertebral compression fracture.

Additives Imparting Antimicrobial Properties to Acrylic Bone Cements

PMMA bone cements are mainly used to fix implanted prostheses and are introduced as a fluid mixture, which hardens over time. The problem of infected prosthesis could be solved due to the development of some new antibacterial bone cements. In this paper, we show the results obtained to develop four different modified PMMA bone cements by using antimicrobial additives, such as gentamicin, peppermint oil incorporated in hydroxyapatite, and silver nanoparticles incorporated in a ceramic glass matrix (2 and 4%). The structure and morphology of the modified bone cements were investigated by SEM and EDS. We perform experimental measurements on wettability, hydration degree, and degradation degree after immersion in simulated body fluid. The cytotoxicity was evaluated by MTT assay using the human MG-63 cell line. Antimicrobial properties were checked against standard strains Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The addition of antimicrobial agents did not significantly affect the hydration and degradation degree. In terms of biocompatibility assessed by the MTT test, all experimental PMMA bone cements are biocompatible. The performance of bone cements with peppermint essential oil and silver nanoparticles against these two pathogens suggests that these antibacterial additives look promising to be used in clinical practice against bacterial infection.

Strategies toward development of antimicrobial biomaterials for dental healthcare applications

Several approaches for elimination of oral pathogens are being explored at the present time since oral diseases remain prevalent affecting approximately 3.5 billion people worldwide. Need for antimicrobial biomaterials in dental healthcare include but is not restricted to designing resin composites and adhesives for prevention of dental caries. Constant efforts are also being made to develop antimicrobial strategies for clearance of endodontic space prior root canal treatment and for treatment of periimplantitis and periodontitis. This article discusses various conventional and nanotechnology-based strategies to achieve antimicrobial efficacy in dental biomaterials. Recent developments in the design and synthesis of antimicrobial peptides and antifouling zwitterionic polymers to effectively lessen the risks of antimicrobial drug resistance are also outlined in this review. Further, the role of contemporary strategies such as use of smart biomaterials, ionic solvent-based biomaterials and quorum quenchers incorporated biomaterials in the elimination of dental pathogens are described in detail. Lastly, we mentioned the approach of using polymers to print custom-made three-dimensional antibacterial dental products via additive manufacturing technologies. This review provides a critical perspective on the chemical, biomimetic, and engineering strategies intended for developing antimicrobial biomaterials that have the potential to substantially improve the dental health.

Recent advances in anticancer and antimicrobial activity of silver nanoparticles synthesized using phytochemicals and organic polymers

Development of eco-friendly synthetic methods has resulted in the production of biocompatible Ag NPs for applications in medical sector. To overcome the prevailing antibiotic resistance in bacteria, Ag NPs are being extensively researched over the past few years due to their broad spectrum and robust antimicrobial properties. Silver nanoparticles are also being studied widely in advanced anticancer therapy as an alternative anticancer agent to combat cancer in an effective manner. Keeping this backdrop in consideration, this review aims to provide an extensive coverage of the recent progresses in the green synthesis of Ag NPs specifically using plant derived reducing agents such phytochemicals and numerous other biopolymers. Current development in antimicrobial activity of Ag NPs against various pathogens has been deliberated at length. Recent advances in potent anticancer activity of the biogenic Ag NPs against various cancerous cell lines has also been discussed in detail. Mechanistic details of the synthesis of Ag NPs, their anticancer and antimicrobial action has also been highlighted.

A review on plant-mediated synthesis of silver nanoparticles, their characterization and applications

For decades, silver has been used as a non-toxic inorganic antimicrobial agent. Silver has a lot of potential in a variety of biological/chemical applications, particularly in the form of nanoparticles (NPs). Eco-friendly synthesis approach for NPs are becoming more common in nanobiotechnology, and the demand for biological synthesis methods is growing, with the goal of eliminating hazardous and polluting agents. Cultures of bacteria, fungi, and algae, plant extracts, and other biomaterials are commonly used for NP synthesis in the ‘green synthesis’ process. Plant-based green synthesis is a simple, fast, dependable, cost-effective, environmentally sustainable, and one-step method that has a significant advantage over microbial synthesis due to the lengthy process of microbial isolation and pure culture maintenance. In this report, we focussed on phytosynthesis of silver nanoparticles (AgNPs) and their characterization using various techniques such as spectroscopy (UV–vis, FTIR), microscopy (TEM, SEM), X-Ray diffraction (XRD), and other particle analysis. The potential applications of AgNPs in a variety of biological and chemical fields are discussed.

A call for action to the biomaterial community to tackle antimicrobial resistance

The global surge of antimicrobial resistance (AMR) is a major concern for public health and proving to be a key challenge in modern disease treatment, requiring action plans at all levels. Microorganisms regularly and rapidly acquire resistance to antibiotic treatments and new drugs are continuously required. However, the inherent cost and risk to develop such molecules has resulted in a drying of the pipeline with very few compounds currently in development. Over the last two decades, efforts have been made to tackle the main sources of AMR. Nevertheless, these require the involvement of large governmental bodies, further increasing the complexity of the problem. As a group with a long innovation history, the biomaterials community is perfectly situated to push forward novel antimicrobial technologies to combat AMR. Although this involvement has been felt, it is necessary to ensure that the field offers a united front with special focus in areas that will facilitate the development and implementation of such systems. This paper reviews state of the art biomaterials strategies striving to limit AMR. Promising broad-spectrum antimicrobials and device modifications are showcased through two case studies for different applications, namely topical and implantables, demonstrating the potential for a highly efficacious physical and chemical approach. Finally, a critical review on barriers and limitations of these methods has been developed to provide a list of short and long-term focus areas in order to ensure the full potential of the biomaterials community is directed to helping tackle the AMR pandemic.

Regulating size of silver nanoparticles on calcium carbonate via ultrasonic spray for effective antibacterial efficacy and sustained release

Calcium carbonate is used as bone-filling material due to its good biocompatibility, bioactivity, and bioabsorbability, but the prevalence of infectious complications associated with calcium carbonate has created a persisting challenge in the treatment of bone defect. Therefore, this greatly necessitate the need to endow calcium carbonate with antibacterial properties. In this study, calcium carbonate powders loaded with silver nanoparticles (Ag-CaCO₃) were prepared in attempt to serve as a novel antibacterial inorganic filler material. This objective was achieved using ultrasonic spray-pyrolysis (USSP) route to produce Ag-CaCO₃ with 1, 5 and 10 mol% silver. The size of silver nanoparticles on CaCO₃ microspheres could be regulated by adjusting silver concentration to facilitate effective release of Ag⁺ ions. This was demonstrated in Ag-CaCO₃ (1), where the lowest silver content at 1 mol% achieved the highest Ag⁺ ions release over 28 days. This in turn gave rise to effective antibacterial efficiency against Staphylococcus aureus and Escherichia coli. Furthermore, CaCO₃ (1) could also support osteoblast-like cells (MG-63) at a cell viability of 80%. Overall, this work extends the capabilities in employing USSP to produce inorganic filler materials with sustained antibacterial properties, bringing one step closer to the development of antibacterial products.

Preparation of antibacterial acrylic bone cement with methacrylate derived from benzothiazole

Methacrylate derived from benzothiazole (BTTMA) was incorporated into acrylic bone cement with a series of mass ratio (5 wt%, 10 wt%, and 15 wt%) with the aim to endow antibacterial activity. Properties such as dough time (t_dough), setting time (t_set), maximum temperature (T_peak), fluid uptake, water solubility, mechanical properties, and biocompatibility of BTTMA containing bone cements were all investigated. Bone cement without BTTMA was used as control and named as plain cement. The results showed that, after incorporating BTTMA, t_dough, flexural modulus, compressive strength of bone cements could be increased, while t_set, T_peak, fluid uptake, water solubility, and flexural strength would be reduced. All of BTTMA containing bone cements did not show hemolytic activity and cell toxicity, but only bone cement with 15 wt% of BTTMA showed antibacterial activity against Staphylococcus aureus (S. aureus).

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

The significance of silver nanostructures has been growing considerably, thanks to their ubiquitous presence in numerous applications, including but not limited to renewable energy, electronics, biosensors, wastewater treatment, medicine, and clinical equipment. The properties of silver nanostructures, such as size, size distribution, and morphology, are strongly dependent on synthesis process conditions such as the process type, equipment type, reagent type, precursor concentration, temperature, process duration, and pH. Physical and chemical methods have been among the most common methods to synthesize silver nanostructures; however, they possess substantial disadvantages and short-comings, especially compared to green synthesis methods. On the contrary, the number of green synthesis techniques has been increasing during the last decade and they have emerged as alternative routes towards facile and effective synthesis of silver nanostructures with different morphologies. In this review, we have initially outlined the most common and popular chemical and physical methodologies and reviewed their advantages and disadvantages. Green synthesis methodologies are then discussed in detail and their advantages over chemical and physical methods have been noted. Recent studies are then reviewed in detail and the effects of essential reaction parameters, such as temperature, pH, precursor, and reagent concentration, on silver nanostructure size and morphology are discussed. Also, green synthesis techniques used for the synthesis of one-dimensional (1D) silver nanostructures have been reviewed, and the potential of alternative green reagents for their synthesis has been discussed. Furthermore, current challenges regarding the green synthesis of 1D silver nanostructures and future direction are outlined. To sum up, we aim to show the real potential of green nanotechnology towards the synthesis of silver nanostructures with various morphologies (especially 1D ones) and the possibility of altering current techniques towards more environmentally friendly, more energy-efficient, less hazardous, simpler, and cheaper procedures.

Cu-loaded Brushite bone cements with good antibacterial activity and operability

Bone defect-related surgical procedures are traumatic processes carrying potential inflammation and infection risks in the clinic, which are associated with prolonged antibiotic therapy that promotes bacterial antibiotic-resistance. In the present study, Cu-loaded brushite bone cements were designed, and the properties of the bone cements were evaluated. The setting time of the cement was prolonged from 12 to 50 min as the copper content increased. All cements were anti-washout, and the injectable coefficient of the cements was approximately 88%. Scanning electron microscopy results revealed that the crystal grains grew larger and thicker as the copper content in the cement increased, and brushite was determined to be the dominant crystalline phase for all the cements. However, a small amount of newly formed calcium copper phosphate was observed in the cement. Simultaneously, band shifts were observed in the Fourier transform infrared spectroscopy results at a Cu content of 5%. Moreover, the addition of Cu improved the compressive strength of brushite cements, and all cements were degradable. Furthermore, the Cu-loaded brushite bone cements performed well in inhibiting the growth and proliferation of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and the diameter of the inhibition zone increased with increasing copper content. The study revealed that the Cu-loaded brushite bone cements possessed good cellular affinity to mouse bone marrow stem cells when a lower dose of copper was added in vitro. These results support the great potential of injectable antibacterial brushite bone cement specifically for bone tissue defect-related repair and regeneration.

Progress of antibiotic-loaded bone cement in joint arthroplasty

Bone cement, consisting of polymethyl methacrylate, is a bioinert material used for prothesis fixation in joint arthroplasty. To treat orthopedic infections, such as periprosthetic joint infection, antibiotic-loaded bone cement (ALBC) was introduced into clinical practice. Recent studies have revealed the limitations of the antibacterial effect of ALBC. Moreover, with the increase in high infection risk patients and highly resistant microbes, more researches and modification of ALBC are required. This paper reviewed latest findings about ALBC for most popular and destructive pathogens, summarized the influence of antibiotic kind, drug dosage, application method, and environment towards characteristic of ALBC. Subsequently, new cement additives and clinical applications of ALBC in joint arthroplasty were also discussed.

Antimicrobial Poly (methyl methacrylate) with Silver Nanoparticles for Dentistry: A Systematic Review

Poly(methyl methacrylate) (PMMA) is a widely used polymer for dental applications, and it is mainly used in the fabrication of dental prostheses. In an increasing number of these applications, the risk of suffering bacterial or fungal infection is higher than 60% among oral-prosthesis users. Some authors have reported the failure of other implants in the human body due to biofilm formation on the surface (mainly for total hip implants). In the dental field, the formation of bacterial and fungal biofilms on prosthesis’s surface is the etiologic factor for stomatitis, mainly caused by Candida albicans and bacteria such as Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis, as well as many others. The antibacterial and antifungal properties of silver nanoparticles (AgNPs) have been widely reported, and their use in dental materials can prevent oral infections, such as candidiasis and stomatitis, and promote better oral health in dental-prosthesis users. They can even be used in other biomedical applications that require controlling biofilm formation on surfaces. In this review, the reported studies that use composites of PMMA and AgNPs (PMMA-AgNPs) for dental applications are listed and checked, with the aim of gaining a wider perspective of the use and application of this approach in the dental field.

High-Potential surface on zirconia ceramics for bacteriostasis and biocompatibility

Bacteria easily adhere, colonize, and form biofilm on oral implants subsequently causing periimplantation periarthritis and mechanical loosening. Previous studies show that a high potential surface on polymeric implants can achieve surface bacteriostasis without side effects. In this study, a high surface potential is introduced to zirconia ceramics to mitigate bacterial infection. Carbon and nitrogen plasma immersion ion implantation (C-PIII and N-PIII) are conducted on zirconia ceramic samples sequentially to elevate the surface potential. The surface with a high potential but without ion leaching exhibits excellent antibacterial effects against oral bacteria and little bacterial resistance is triggered. The surface also has high strength and excellent biocompatibility. The nitrogen-containing inorganic structure with high potential can actualize bacteriostasis and biocompatibility on zirconia ceramics simultaneously and this new strategy can enhance the antibacterial ability of oral implants.

A review of calcium phosphate cements and acrylic bone cements as injectable materials for bone repair and implant fixation

Treatment of bone defects caused by trauma or disease is a major burden on human healthcare systems. Although autologous bone grafts are considered as the gold standard, they are limited in availability and are associated with post-operative complications. Minimally invasive alternatives using injectable bone cements are currently used in certain clinical procedures, such as vertebroplasty and balloon kyphoplasty. Nevertheless, given the high incidence of fractures and pathologies that result in bone voids, there is an unmet need for injectable materials with desired properties for minimally invasive procedures. This paper provides an overview of the most common injectable bone cement materials for clinical use. The emphasis has been placed on calcium phosphate cements and acrylic bone cements, while enabling the readers to compare the opportunities and challenges for these two classes of bone cements. This paper also briefly reviews antibiotic-loaded bone cements used in bone repair and implant fixation, including their efficacy and cost for healthcare systems. A summary of the current challenges and recommendations for future directions has been brought in the concluding section of this paper.

Microcellular Environmental Regulation of Silver Nanoparticles in Cancer Therapy: A Critical Review

Silver nanoparticles (AgNPs) play significant roles in various cancer cells such as functional heterogeneity, microenvironmental differences, and reversible changes in cell properties (e.g., chemotherapy). There is a lack of targets for processes involved in tumor cellular heterogeneity, such as metabolic clampdown, cytotoxicity, and genotoxicity, which hinders microenvironmental biology. Proteogenomics and chemical metabolomics are important tools that can be used to study proteins/genes and metabolites in cells, respectively. Chemical metabolomics have many advantages over genomics, transcriptomics, and proteomics in anticancer therapy. However, recent studies with AgNPs have revealed considerable genomic and proteomic changes, particularly in genes involved in tumor suppression, apoptosis, and oxidative stress. Metabolites interact biochemically with energy storage, neurotransmitters, and antioxidant defense systems. Mechanobiological studies of AgNPs in cancer metabolomics suggest that AgNPs may be promising tools that can be exploited to develop more robust and effective adaptive anticancer therapies. Herein, we present a proof-of-concept review for AgNPs-based proteogenomics and chemical metabolomics from various tumor cells with the help of several technologies, suggesting their promising use as drug carriers for cancer therapy.

Implant system for treatment of the orbital floor defects of blowout fractures in the maxillofacial region using polypropylene yarn and bioactive bone cement

Fractures in the craniofacial region are a serious problem in terms of treatment. The most reasonable solution is the use of individual implants dedicated to a specific patient. The aim of this study was to develop the implant system specifically for treatment of the orbital floor defects of blowout fractures of maxillofacial region, using polypropylene yarn and bone cement. Three types of bone cement were used to fix the polypropylene yarn: unmodified, antibiotic-loaded, and modified with nanometals. The following research was carried out: selection of cement production parameters, assessment of the curing time, measurement of polymerization temperature, an analysis of microstructure and surface topography, evaluation of wettability, measurement of microhardness, and studies of bactericidal effectiveness. The research confirms the possibility of using bone cement and polypropylene yarn for an individual implant, dedicated to the fractures treatment in the maxillofacial region. Moreover, the bactericidal properties of the proposed modifications for bone cement have been verified; hence, bioactive cements are recommended for use in the case of infectious complications.

PMMA-Based Bone Cements and the Problem of Joint Arthroplasty Infections: Status and New Perspectives

Polymethyl methacrylate (PMMA)-based bone cement is a biomaterial that has been used over the last 50 years to stabilize hip and knee implants or as a bone filler. Although PMMA-based bone cement is widely used and allows a fast-primary fixation to the bone, it does not guarantee a mechanically and biologically stable interface with bone, and most of all it is prone to bacteria adhesion and infection development. In the 1970s, antibiotic-loaded bone cements were introduced to reduce the infection rate in arthroplasty; however, the efficiency of antibiotic-containing bone cement is still a debated issue. For these reasons, in recent years, the scientific community has investigated new approaches to impart antibacterial properties to PMMA bone cement. The aim of this review is to summarize the current status regarding antibiotic-loaded PMMA-based bone cements, fill the gap regarding the lack of data on antibacterial bone cement, and explore the progress of antibacterial bone cement formulations, focusing attention on the new perspectives. In particular, this review highlights the innovative study of composite bone cements containing inorganic antibacterial and bioactive phases, which are a fascinating alternative that can impart both osteointegration and antibacterial properties to PMMA-based bone cement.

Effect of Physiological Fluids Contamination on Selected Mechanical Properties of Acrylate Bone Cement

This study analyses the degradation rate of selected mechanical properties of bone cement contaminated with human blood and saline solution. During the polymerisation stage, the PMMA cement specimens were supplemented with the selected physiological fluids in a range of concentrations from 0% to 10%. The samples were then subjected to the standardised compression tests, as per ISO 5833: 2002, and hardness tests. The obtained results were analysed statistically to display the difference in the degradation of the material relative to the degree of contamination. Subsequently, numerical modelling was employed to determine the mathematical relationship between the degree of contamination and the material strength degradation rate. The introduction of various concentrations of contaminants into the cement mass resulted in a statistically significant change in their compressive strength. It was shown that the addition of more than 4% of saline and more than 6% of blood (by weight) causes that the specimens exhibit lower strength than the minimum critical value of 70 MPa, specified in the abovementioned International Standard. It was further revealed that the cement hardness characteristics degraded accordingly. The mathematical models showed a very good fit with the results from the experiments: The coefficient of determination R2 was 0.987 in the case of the linear hardness model for blood and 0.983 for salt solution; secondly, the values of R2 for the third-degree polynomial model of compressive strength were 0.88 for blood and 0.92 for salt. From the results, it can be seen that there is a quantitative/qualitative relationship between the contamination rate and the drop in the tested mechanical characteristics. Therefore, great effort must be taken to minimise the contact of the bone cement with physiological fluids, which naturally occur in the operative field, particularly when the material cures, in order to prevent the cement material strength declining below the minimum threshold specified in the ISO standard.

Antibacterial PMMA Composite Cements with Tunable Thermal and Mechanical Properties

PMMA-based cements are the most used bone cements in vertebroplasty and total hip arthroplasty. However, they present several drawbacks, including susceptibility to bacterial infection, monomer leakage toxicity, and high polymerization temperature, which can all lead to damage to the surrounding tissues and their failure. In the present study, silver nanowires (AgNWs) have been introduced to bestow antibacterial properties; chitosan (CS) to promote porosity and to reduce the polymerization temperature, without negatively affecting the mechanical performance; and methacryloyl chitosan (CSMCC) to promote cross-linking with methyl methacrylate (MMA) and reduce the quantity of monomer required for polymerization. Novel PMMA cements were formulated containing AgNWs (0 and 1% w/w) and CS or CSMCC at various concentrations (0, 10, 20, and 30% w/w), testing two different ratios of powder and MMA (P/L). Mechanical, thermal, antibacterial, and cytotoxic properties of the resulting composite cements were tested. Cements with concentrations of CS > 10% presented a significantly reduced polymerization temperature. The mechanical performances were affected for concentrations > 20% with a P/L concentration equal to 2:1. Concentrations of AgNWs as low as 1% w/w conferred antimicrobial activity against S. aureus, whereas biofilm formation on the surface of the cements was increased when CS was included in the preparation. The combination of CS and AgNWs allowed a higher concentration of Ag⁺ to be released over time with enhanced antimicrobial activity. Inclusion of AgNWs did not affect cell viability on the scaffolds. In conclusion, a combination of CS and AgNWs may be beneficial for reducing both polymerization temperature and biofilm formation, without significantly affecting mesenchymal stem cell proliferation on the scaffolds. No advantages have been noticed as a result of the reducing P/L ratio or using CSMCC instead of CS.

The Effect of Surface Modification of Ti13Zr13Nb Alloy on Adhesion of Antibiotic and Nanosilver-Loaded Bone Cement Coatings Dedicated for Application as Spacers

Spacers, in terms of instruments used in revision surgery for the local treatment of postoperative infection, are usually made of metal rod covered by antibiotic-loaded bone cement. One of the main limitations of this temporary implant is the debonding effect of metal-bone cement interface, leading to aseptic loosening. Material selection, as well as surface treatment, should be evaluated in order to minimize the risk of fraction and improve the implant-cement fixation the appropriate manufacturing. In this study, Ti13Zr13Nb alloys that were prepared by Selective Laser Melting and surface treated were coated with bone cement loaded with either gentamicin or nanosilver, and the effects of such alloy modifications were investigated. The SLM-made specimens of Ti13Zr13Nb were surface treated by sandblasting, etching, or grounding. For each treatment, Scanning Electron Microscope (SEM), contact profilometer, optical tensiometer, and nano-test technique carried out microstructure characterization and surface analysis. The three types of bone cement i.e., pure, containing gentamicin and doped with nanosilver were applied to alloy surfaces and assessed for cement cohesion and its adhesion to the surface by nanoscratch test and pull-off. Next, the inhibition of bacterial growth and cytocompatibility of specimens were investigated by the Bauer-Kirby test and MTS assay respectively. The results of each test were compared to the two control groups, consisting of commercially available Ti13Zr13Nb and untreated SLM-made specimens. The highest adhesion bone cement to the titanium alloy was obtained for specimens with high nanohardness and roughness. However, no explicit relation of adhesion strength with wettability and surface energy of alloy was observed. Sandblasting or etching were the best alloys treatments in terms of the adhesion of either pure or modified bone cements. Antibacterial additives for bone cement affected its properties. Gentamicin and nanosilver allowed for adequate anti-bacterial protection while maintaining the overall biocompatibility of obtained spacers. However, they had different effects on the cement's adhesive capacity or its own cohesion. Furthermore, the addition of silver nanoparticles improved the nanomechanical properties of bone cements. Surface treatment and method of fabrication of titanium affected surface parameters that had a significant impact on cement-titanium fixation.

Antibacterial Activity and Cytocompatibility of Bone Cement Enriched with Antibiotic, Nanosilver, and Nanocopper for Bone Regeneration

Bacterial infections due to bone replacement surgeries require modifications of bone cement with antibacterial components. This study aimed to investigate whether the incorporation of gentamicin or nanometals into bone cement may reduce and to what extent bacterial growth without the loss of overall cytocompatibility and adverse effects in vitro. The bone cement Cemex was used as the base material, modified either with gentamicin sulfate or nanometals: Silver or copper. The inhibition of bacterial adhesion and growth was examined against five different bacterial strains along with integrity of erythrocytes, viability of blood platelets, and dental pulp stem cells. Bone cement modified with nanoAg or nanoCu revealed greater bactericidal effects and prevented the biofilm formation better compared to antibiotic-loaded bone cement. The cement containing nanoAg displayed good cytocompatibility without noticeable hemolysis of erythrocytes or blood platelet disfunction and good viability of dental pulp stem cells (DPSC). On the contrary, the nanoCu cement enhanced hemolysis of erythrocytes, reduced the platelets aggregation, and decreased DPSC viability. Based on these studies, we suggest the modification of bone cement with nanoAg may be a good strategy to provide improved implant fixative for bone regeneration purposes.

Gentamicin-loaded silk/nanosilver composite scaffolds for MRSA-induced chronic osteomyelitis

Methicillin-resistant Staphylococcus aureus (MRSA) often induces chronic osteomyelitis and then bone defects. Here, gentamicin-loaded silk/nanosilver composite scaffolds were developed to treat MRSA-induced chronic osteomyelitis. AgNO3 was reduced with silk as a reducing agent in formic acid, forming silver nanoparticles in situ that were distributed uniformly in the composite scaffolds. Superior antibacterial properties against MRSA were achieved for the composite scaffolds, without the compromise of osteogenesis capacity. Then gentamicin was loaded on the scaffolds for better treatment of osteomyelitis. In vivo results showed effective inhibition of the growth of MRSA bacteria, confirming the promising future in the treatment of chronic osteomyelitis.

Carbon nanotube incorporation in PMMA to prevent microbial adhesion

Although PMMA-based biomaterials are widely used in clinics, a major hurdle, namely, their poor antimicrobial (i.e., adhesion) properties, remains and can accelerate infections. In this study, carboxylated multiwalled carbon nanotubes (CNTs) were incorporated into poly(methyl methacrylate) (PMMA) to achieve drug-free antimicrobial adhesion properties. After characterizing the mechanical/surface properties, the anti-adhesive effects against 3 different oral microbial species (Staphylococcus aureus, Streptococcus mutans, and Candida albicans) were determined for roughened and highly polished surfaces using metabolic activity assays and staining for recognizing adherent cells. Carboxylated multiwalled CNTs were fabricated and incorporated into PMMA. Total fracture work was enhanced for composites containing 1 and 2% CNTs, while other mechanical properties were gradually compromised with the increase in the amount of CNTs incorporated. However, the surface roughness and water contact angle increased with increasing CNT incorporation. Significant anti-adhesive effects (35~95%) against 3 different oral microbial species without cytotoxicity to oral keratinocytes were observed for the 1% CNT group compared to the PMMA control group, which was confirmed by microorganism staining. The anti-adhesive mechanism was revealed as a disconnection of sequential microbe chains. The drug-free antimicrobial adhesion properties observed in the CNT-PMMA composite suggest the potential utility of CNT composites as future antimicrobial biomaterials for preventing microbial-induced complications in clinical settings (i.e., Candidiasis).

Data for vancomycin elution, activity and impact on mechanical properties when incorporated into orthopedic bone cement

In this article, we report data on the antibiotic elution and efficacy, and mechanical properties of Palacos bone cement with different amounts of added vancomycin (0.0, 0.125, 0.25, 0.5, 1.0, 2.0 g), see “Vancomycin elution, activity and impact on mechanical properties when added to orthopedic bone cement” (Bishop et al., 2018) [1]. Mechanical testing was performed for four-point bending, compression, and fracture toughness. The release characteristics of vancomycin was recorded for up to 60 days to estimate the elution profile. The eluted vancomycin efficacy at eliminating the four most common causative orthopedic implant pathogens is also reported.

Biomedical Applications of Silver Nanoparticles: An Up-to-Date Overview

During the past few years, silver nanoparticles (AgNPs) became one of the most investigated and explored nanotechnology-derived nanostructures, given the fact that nanosilver-based materials proved to have interesting, challenging, and promising characteristics suitable for various biomedical applications. Among modern biomedical potential of AgNPs, tremendous interest is oriented toward the therapeutically enhanced personalized healthcare practice. AgNPs proved to have genuine features and impressive potential for the development of novel antimicrobial agents, drug-delivery formulations, detection and diagnosis platforms, biomaterial and medical device coatings, tissue restoration and regeneration materials, complex healthcare condition strategies, and performance-enhanced therapeutic alternatives. Given the impressive biomedical-related potential applications of AgNPs, impressive efforts were undertaken on understanding the intricate mechanisms of their biological interactions and possible toxic effects. Within this review, we focused on the latest data regarding the biomedical use of AgNP-based nanostructures, including aspects related to their potential toxicity, unique physiochemical properties, and biofunctional behaviors, discussing herein the intrinsic anti-inflammatory, antibacterial, antiviral, and antifungal activities of silver-based nanostructures.

Copper-Doped Bioactive Glass as Filler for PMMA-Based Bone Cements: Morphological, Mechanical, Reactivity, and Preliminary Antibacterial Characterization

To promote osteointegration and simultaneously limit bacterial contamination without using antibiotics, we designed innovative composite cements containing copper (Cu)-doped bioactive glass powders. Cu-doped glass powders were produced by a melt and quenching process, followed by an ion-exchange process in a Cu salt aqueous solution. Cu-doped glass was incorporated into commercial polymethyl methacrylate (PMMA)-based cements with different viscosities. The realized composites were characterized in terms of morphology, composition, leaching ability, bioactivity, mechanical, and antibacterial properties. Glass powders appeared well distributed and exposed on the PMMA surface. Composite cements showed good bioactivity, evidencing hydroxyapatite precipitation on the sample surfaces after seven days of immersion in simulated body fluid. The leaching test demonstrated that composite cements released a significant amount of copper, with a noticeable antibacterial effect toward Staphylococcus epidermidis strain. Thus, the proposed materials represent an innovative and multifunctional tool for orthopedic prostheses fixation, temporary prostheses, and spinal surgery.