Antibacterial Filler Research Articles

Preparation of transparent and flexible regenerated kenaf CNF composite films with curcumin-metal complex for food packaging applications

Cellulose nanofibers (CNF) derived from kenaf plant were combined with curcumin (Cur)-metal complexes to produce regenerated composite films. Cur was used to synthesize homoleptic Cur-metal complexes with diamagnetic Zn(II) and paramagnetic Cu(II) metal ions. Cur-Zn(II) complex and Cur-Cu(II) complex were synthesized under the same reaction conditions to check the synergistic effect of engaging the diketone electrons of Cur with strong coordination bonds with two different metal ions. The synthesized Cur-metal complexes were used as fillers to produce CNF composite films for biodegradable food packaging film. Results showed that the Cur-Zn(II) complex-loaded CNF composite films exhibit higher antioxidant activity than other films whereas Cur-Cu(II) complex-loaded CNF composite films showed prominent antibacterial activity against foodborne pathogenic bacteria such as Listera monocytogenes and Escherichia coli. It is due to the coordination of the diketone electron of Cur with diamagnetic and paramagnetic metal ions that influenced the antioxidant and antibacterial properties of Cur. Overall, this study proved that it was possible to use Cur in the form of Cur-Zn(II) complex as an antioxidant filler and Cur-Cu(II) complex as an antibacterial filler for active food packaging applications.

Incorporation of hydroxyapatite and cerium oxide nanoparticle scaffold as an antibacterial filler matrix for biomedical applications.

Managing bone healing is essential for preventing problems such as non-union, bacterial infection, structural instability, psychological, and physical damage in patients. The need to use antibiotics less often has prompted researchers to look at possible substitutes, such as nanoparticles. In this investigation, we choose to employ cerium oxide nanoparticles due to their unique antibacterial properties based on redox reactions. The cerium oxide-hydroxyapatite composite was synthesized, calcined, and ball-milled to create a fine CeO2-HA powder. Luffa cylindrica sponge was used to prepare the scaffold, and X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the structural and morphological features. Rapid upregulation of osteogenesis marker genes confirmed that CeO2-HA nanoparticles in the scaffolds promoted osteoblast cell proliferation and osteogenic differentiation. The cell viability test was conducted by MTT assay. When the CeO2-HA composite was cultured with S. aureus, it showed signs of having more antibacterial efficacy than pure HA.

Development of the Properties of Zinc Polycarboxylate Cement Used as a Basis for Dental Fillings Using Zink Oxide Nanoparticles Prepared by Green Chemistry Method

Most dental supplies don't seem to be much of a barrier against germ infiltration. Therefore, the filling must be done with perfect caution and high antimicrobial effectiveness. When dental erosion occurs due to germs that lead to caries, a dental filling is used, creating a small microscopic space between the dental filling and the root end infiltration. This allowed the tooth to be penetrated for the second time, which was the research problem. Adding two compounds to antibacterial fillers (zinc polycarboxylate cement) made them work better: Firstly, was zinc oxide (ZnO) that was made chemically, and secondly, was green ZnO nanoparticles that were made from orange peels and mixed with ZPCC in different amounts. The study was conducted on the formed nanocomposite using FTIR, UV-vis, FESEM, sitting time, and antibacterial measurements. The biological activity was tested using Staphylococcus aureus, Escherichia coli, and Candida albicans.

The effect of quaternary ammonium polyethylenimine nanoparticles on bacterial adherence, cytotoxicity, and physical and mechanical properties of experimental dental composites

A significant problem related to the functioning of resin-based composites for dental fillings is secondary or recurrent caries, which is the reason for the need for repeated treatment. The cross-linked quaternary ammonium polyethylenimine nanoparticles (QA-PEI-NPs) have been shown to be a promising antibacterial agent against different bacteria, including cariogenic ones. However, little is known about the properties of dental dimethacrylate polymer-based composites enriched with QA-PEI-NPs. This research was carried out on experimental composites based on bis-GMA/UDMA/TEGDMA matrix enriched with 0.5, 1, 1.5, 2 and 3 (wt%) QA-PEI-NPs and reinforced with two glass fillers. The cured composites were tested for their adherence of Streptococcus Mutans bacteria, cell viability (MTT assay) with 48 h and 10-days extracts , degree of conversion (DC), water sorption (WSO), and solubility (WSL), water contact angle (CA), flexural modulus (E), flexural strength (FS), compressive strength (CS), and Vickers microhardness (HV). The investigated materials have shown a complete reduction in bacteria adherence and satisfactory biocompatibility. The QA-PEI-NPs additive has no effect on the DC, VH, and E values. QA-PEI-NPs increased the CA (a favorable change), the WSO and WSL (unfavorable changes) and decreased flexural strength, and compressive strength (unfavorable changes). The changes mentioned were insignificant and acceptable for most composites, excluding the highest antibacterial filler content. Probably the reason for the deterioration of some properties was low compatibility between filler particles and the matrix; therefore, it is worth extending the research by surface modification of QA-PEI-NPs to achieve the optimum performance characteristics.

Effect of composite resin containing antibacterial filler on sugar-induced pH drop caused by whole saliva bacteria

Secondary caries around restorations is a major problem and can be attributed to bacteria invading microgaps formed at the tooth-restoration interface. An antibacterial composite resin containing quaternary ammonium silica (QASi) filler has been reported to inhibit enamel demineralization in situ. However, whether the prevention of enamel demineralization by QASi-containing composite resin is because of the reduced metabolic activity of acid-producing saliva bacteria is unclear. The purpose of this study was to compare the effects of QASi-containing composite resin and 2 other restorative materials on the viability of salivary bacteria and sugar-induced acid production. Whole saliva from each of the 30 study participants, 14 at high risk and 16 at low risk for caries, was brought into contact with quadruplicate specimens of 3 restorative materials, Infinix Flowable Composite, an anti-bacterial composite resin containing 1.5% QASi filler (Nobio), Filtek Supreme Flowable Restorative (3M), a conventional flowable composite resin, and dental amalgam (Silmet). Bacterial growth and sugar-induced acid production on each restorative material were measured every 20 minutes for 18 hours. Caries risk groups were compared using the t test and repeated measures analysis of variance (α=.05). When significant, Bonferroni multiple comparisons were used. On average, the saliva with the QASi-containing composite resin specimens maintained a near-neutral pH, not dropping below pH 6.0. The saliva associated with both conventional restorative materials exhibited a pH drop below 5.5 (P<.001), the critical threshold for tooth demineralization according to the Stephan curve. Virtually no growth was measured on the surface of the antibacterial composite resin, whereas bacteria grew on the conventional composite resin and dental amalgam (P<.001). No differences were observed between participants at high and low risk of caries. Unlike amalgam and conventional composite resin, the QASi-containing composite resin showed a near-complete shutdown of the metabolic activity of salivary bacteria upon contact and virtually no bacterial viability. This suggests that the prevention of tooth demineralization by QASi-containing restoratives is associated with a significant reduction in bacterial metabolic activity.

Making graphene oxide (GO)-cladded SiO2 spheres (SiO2 @GO) as inorganic fillers for dental restorative resin composites

ObjectiveGraphene oxide (GO) is of great interest in dentistry as the functional filler, mainly owing to its ability to inhibit the formation of cariogenic bacteria and possess low cytotoxicity to different cells, such as human dental pulp cells, HeLa cells, etc. However, its typical brown color limits the practical application. MethodsHere, the refractive-index-matched monodisperse SiO2 were used as the supporting substrates to synthesize GO-cladded SiO2 spheres (xSiO2 @ yGO) through a mild electrostatic self-assembly process, where x and y represent the amount of SiO2 and GO in the reaction mixture, respectively. The morphology and the optical performance of the obtained xSiO2 @ yGO particles were modulated by varying the mass ratio of SiO2 and GO (5:1, 10:1, 50:1, and 100:1). All developed hybrid particles were silanized and formulated with dimethacrylate-based resins. These were tested for curing depth, polymerization conversion, mechanical performance, in vitro cell viability, and antibacterial activity. ResultsOf all xSiO2 @ yGO materials, increasing the mass ratio to 100:1 made the 100SiO2 @GO particles appear light brown and possess the lowest light absorbance from 300 to 800 nm. The results of CIEL*a*b* system showed that all these hybrid particles exhibited obvious discoloration compared with SiO2 and GO, where 100SiO2 @GO possessed the smallest color difference. Furthermore, following the results of curing depth, polymerization conversion, and mechanical performance of dental composites, the optimal filler composition was 100SiO2 @GO at 5 wt% filler loading. The resultant 100SiO2 @GO-filled composite produced the highest flexural strength (115 ± 12 MPa) and the lowest bacterial concentration (6.7 × 108 CFU/mL) than those of the resin matrix (78 ± 11 MPa; 9.2 × 108 CFU/mL) and 5 wt% SiO2-filled composite (106 ± 9 MPa; 9.1 × 108 CFU/mL), respectively, without affecting in vitro cell viability. SignificanceThe facile and mild synthesis of xSiO2 @ yGO hybrid particles provided a convenient way to tune their optical property. The optimal 100SiO2 @GO particles could be considered as the promising antibacterial filler to be applied in dental care and therapy.

Bioactive Dental Resin Composites with MgO Nanoparticles.

Photoactivating dental resin composites have been the most prevailing material for repairing dental defects in various clinical scenarios due to their multiple advantages. However, compared to other restorative materials, the surface of resin-based composites is more susceptible to plaque biofilm accumulation, which can lead to secondary caries and restoration failure. This study introduced different weight fractions (1, 2, 5, 10, and 15%) of magnesium oxide nanoparticles (MgONPs) as antibacterial fillers into dental resin composites. Multifarious properties of the material were investigated, including antibacterial activity against a human salivary plaque-derived biofilm, cytotoxicity on human gingival fibroblasts, mechanical and physicochemical properties as well as the performance when subjected to thermocycling aging treatment. Results showed that the incorporation of MgONPs significantly improved the composites' anti-biofilm capability even at a low amount of 2 wt % without compromising the mechanical, physicochemical, and biocompatibility performances. The results of the thermocycling test suggested certain of aging resistance. Moreover, a small amount of MgONPs possibly made a difference in enhancing photoactivated polymerization and increasing the curing depth of experimental resin composites. Overall, this study highlights the potential of MgONPs as an effective strategy for developing antibacterial resin composites, which may help mitigating cariogenic biofilm-associated secondary caries.

Antioxidation Effect of Graphene Oxide on Silver Nanoparticles and Its Use in Antibacterial Applications.

Silver nanoparticles (AgNPs) have drawn great attention due to their outstanding antibacterial effect in a wide range of applications, such as biomass packaging materials, wound dressings, flexible sensors, etc. However, the oxidation of AgNPs limits the antibacterial effect. Firstly, the effects of pretreatment methods on the antibacterial property of AgNPs were investigated by the shake flask method and agar diffusion plate method. Secondly, graphene oxide/silver nanoparticle (GO/AgNPs) nanocomposite prepared by an in-situ growth method was used as antibacterial filler for polyacrylate emulsion via a blending method. The antibacterial mechanism of GO/AgNPs was revealed by comparing the actual contents of oxygen with the theoretically calculated contents of oxygen. Finally, the polyacrylate/graphene oxide/silver nanoparticles (PA/GO/AgNPs) composite emulsion was applied onto a leather surface using a layer-by-layer spraying method to improve the leather's antibacterial properties. The results showed that ultraviolet irradiation could better maintain the antibacterial property of AgNPs, while GO could improve the dispersibility of AgNPs and prevent their oxidation. The leather finished with the PA/GO/AgNPs-2 wt% composite emulsion showed the highest bacteriostatic rate of 74%, demonstrating its great potential in the application of antibacterial leather products.

Antibacterial and physical properties of resin cements containing MgO nanoparticles

Cariogenic bacteria and dental plaque biofilm at prosthesis margins are considered a primary risk factor for failed restorations. Resin cement containing antibacterial agents can be beneficial in controlling bacteria and biofilm. This work aimed to evaluate the impact of incorporating magnesium oxide nanoparticles (MgONPs) as an antibacterial filler into dual-cure resin cement on bacteriostatic activity and physical properties, including mechanical, bonding, and physicochemical properties, as well as performance when subjected to a 5000-times thermocycling regimen. Experimental resin cements containing MgONPs of different mass fractions (0, 2.5%, 5%, 7.5% and 10%) were developed. Results suggested that the inclusion of MgONPs markedly improved the materials’ bacteriostatic effect against Streptococcus mutans without compromising the physical properties when its addition reached 7.5 wt%. The mechanical properties of the specimens did not significantly decline after undergoing aging treatment, except for the flexural properties. In addition, the cements displayed good bonding performance and the material itself was not prone to cohesive fracture in the failure mode analysis. Furthermore, MgONPs possibly have played a role in decelerating material aging during thermocycling and enhancing bonding fastness in the early stage of cementation, which requires further investigation. Overall, developing MgONPs-doped resin cements can be a promising strategy to improve the material's performance in inhibiting cariogenic bacteria at restoration margins, in order to achieve a reduction in biofilm-associated secondary caries and a prolonged restoration lifespan.

Polyhexamethylene guanidine molybdate as an efficient antibacterial filler in epoxy coating for inhibiting sulfate reducing bacteria biofilm

Readily synthesized and highly antibacterial polyhexamethylene guanidine molybdate (PHMG-MoO4) can be used as a filler to greatly improve the resistance of epoxy coating to sulfate reducing bacteria (SRB) biofilm. In SRB inoculated medium, no SRB biofilm formed on PHMG-MoO4/epoxy coating after 120 days, and the corrosion current density of the epoxy coating painted carbon steel decreased by 99.0 % after addition of PHMG-MoO4 in the coating. There were also fewer fouling organisms on PHMG-MoO4/epoxy coating after 4 months of immersion in the actual seawater. The PHMG-MoO4 with low water solubility can remain in epoxy coating for a long time and therefore effectively and continuously inhibited the bacteria on the coating.

Development of novel hydrophilic and antibacterial silicone rubber impression material for dental application.

This investigation aimed to develop a novel hydrophilic and antibacterial silicone rubber impression material for dental application. The basic formula of the new silicone rubber was determined on a preliminary study, and 6% polyether modified silicone oil was added as wetting agent to provide the hydrophilicity. No-vel nano-antibacterial inorganic fillers containing quaternary ammonium salt with long chain alkyl were incorporated into the hydrophilic silicone rubber impression materials at a mass fraction of 0%, 1%, 2%, 3%, 4%, or 5%. A commercial silicone rubber impression material was used as control. The mechanical properties, wettability, detail reproducibility, dimensional stability, and mixing time of silicone rubber materials were measured. Thin-film adhesion method and cell counting kit-8 method were used to detect the antibacterial property and cytotoxicity. Scanning electron microscopy (SEM) was chosen to observe the micromorphology of the novel silicone rubber. When the content of antibacterial filler exceeded 4%, the mechanical properties of the new silicone rubber decreased significantly (P<0.05). Compared with those of the control group, the contact angle and linear size change rate of different groups had no significant change at different time nodes, and the detail reproducibility was intact (P>0.05). The addition of antibacterial fillers had no significant effect on the mixing time (P>0.05). Adding 4% antibacterial fillers could result in the antibacterial rate of 95.26%, showing good antibacterial properties. No significant difference was found in the cytotoxicity of all groups (P>0.05). The SEM pictures of the cross section of the silicone rubber sample showed that the fillers had good compatibility with the silicone rubber matrix and distributed in the matrix evenly. A novel silicone rubber impression material containing 6% polyether modified silicone oil could obtain promising hydrophilic and antibacterial properties after being added with 4% antibacterial inorganic fillers.

Development of Novel Antimicrobial Dental Composite Resin with Nano Cerium Oxide Fillers

Objectives To assess the antibacterial efficacy of experimental dental composite resin with cerium oxide nanoparticles as fillers. Methods The cerium oxide nanoparticles were prepared by the coprecipitation procedure. Synthesized 3wt% CeO2 nanoparticles were added to the composite resin as antibacterial filler. Experimental composite resin was manually prepared by adding ingredients. The resin matrix consisted of two mixed monomers, bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate, diketone as the photo initiator, and N, N-dimethylaminoethyl methacrylate as a coinitiator. The antibacterial efficacy against Streptococcus mutans, Streptococcus mitis, Streptococcus aureus, and Lactobacillus spp. bacterial strains was tested using the microdilution method keeping commercially available 3M Filtek Z250 restorative composite as control. Results The experimental dental composite demonstrated 99.503% efficacy against Streptococcus mutans, 99.441% efficacy against Streptococcus mitis, 99.416% efficacy against Streptococcus aureus, and 99.233% efficacy against Lactobacillus spp. Conclusion Integrating cerium oxide nanoparticles as fillers into dental composite resin can be promising in terms of antibacterial activity, provided furthermore study has to be conducted to examine other properties. Clinical Significance. Previous studies attempted adding CeO2 nanoparticles into acrylic resins that showed improvement in mechanical properties, but literature is nil on the dental composite resin and cerium oxide nanoparticles. This study demonstrates the development of an experimental antibacterial dental composite resin that can resolve most of the problems related to secondary caries around dental composite restorations.

Chemical Transformation of Lignosulfonates to Lignosulfonamides with Improved Thermal Characteristics

Lignin is an abundantly occurring aromatic biopolymer that receives increasing attention as, e.g., a biofiller in polymer composites. Though its structure depends on the plant source, it is a valuable component showing biodegradability, antioxidant, and ultra-violet (UV) absorption properties. Lignosulfonates, a by-product of the paper and pulping industries formed as a result of the implementation of the sulfite process, have been used in the presented study as a raw material to obtain a sulfonamide derivative of lignin. Hereby, a two-step modification procedure is described. The obtained materials were investigated by means of FTIR, WAXD, SS-NMR, SEM, and TGA; the results of spectroscopic investigations confirm the formation of a sulfonamide derivative of lignin via the proposed modification method. The obtained modified lignin materials showed significantly improved thermal stability in comparison with the raw material. The internal structure of the lignosulfonate was not altered during the modification process, with only slight changes of the morphology, as confirmed by the WAXD and SEM analyses. The manufactured sulfonamide lignin derivatives show great promise in the potential application as an antibacterial filler in advanced biopolymeric composites.

Porous agarose/Gd-hydroxyapatite composite bone fillers with promoted osteogenesis and antibacterial activity

Artificial bone fillers are essentially required for repairing bone defects, and developing the fillers with synergistic biocompatibility and anti-bacterial activity persists as one of the critical challenges. In this work, a new agarose/gadolinium-doped hydroxyapatite filler with three-dimensional porous structures was fabricated. For the composite filler, agarose provides three-dimensional skeleton and endows porosity, workability, and high specific surface area, hydroxyapatite (HA) offers the biocompatibility, and the rare earth element gadolinium (Gd) acts as the antibacterial agent. X-ray photoelectron spectroscopy detection showed the doping of Gd in HA lattice with the formation of Gd-HA interstitial solid solution. Attenuated total reflection Fourier transform infrared spectroscopy imaging suggested chemical interactions between agarose and Gd-HA, and the physical structure of agarose was tuned by the Gd-doped HA. Cytotoxicity testing and alizarin red staining experiments using mouse pro-osteoblasts (MC3T3-E1) revealed remarkable bioactivity and osteogenic properties of the composite fillers, and proliferation and growth rates of the cells increased in proportion to Gd content in the composites. Antibacterial testing using the gram-positive bacteria S. aureus and the gram-negative bacteria E. coli indicated promising antibacterial properties of the fillers. Meanwhile, the antibacterial properties of composite filles were enhanced with the increase of Gd content. The antibacterial fillers with porous structure and excellent physicomechanical properties show inspiring potential for bone defect repair.

One-pot synthesis of silver nanoparticle deposited cellulose nanocrystals with high colloidal stability for bacterial contaminated water purification

Cellulose nanocrystals (CNCs) have been utilized as a scaffold to immobilize silver nanoparticles (AgNPs) for their potential application as an antibacterial agent and bactericidal filler. However, the present implemented strategies involve synthesis by multi-step and utilize environment non-friendly reducing agents for the deposition of AgNPs on CNCs. Furthermore, the long-time aqueous dispersion stability of prepared AgNPs hybrids is another issue of concern for their efficient utilization as an antibacterial filler. We have developed an environmentally benign one-pot method using a biocompatible polyvinyl+pyrolidone (PVP) as a reducing agent to deposit AgNPs on CNCs. The developed method exhibited the uniform in-situ deposition of AgNPs on CNCs. The formed (CNC-PVP-Ag) nanohybrid displayed excellent long time aqueous colloidal stability (8 months), antibacterial and anti-biofouling activities (12.5 µg/mL and 25 µg/mL for E. coli and S. aureus) which is 4 and 2 times lower than AgNPs (w/o CNCs) prepared by the identical process as of CNC-PVP-Ag. As water-borne microbial contaminations are a global water quality concern, the excellent antibacterial and anti-biofouling activity of CNC-PVP-Ag was applied for water purification. An efficient bacterial filtration performance (100% reduction of Escherichia coli viability) was achieved after two filtration cycles.

An antibacterial dental light-cured glass-ionomer cement with improved hardness

An antibacterial dental light-cured glass-ionomer cement has been developed and evaluated. An antibacterial furanone derivative was synthesized and covalently attached onto the surface of alumina filler particles. The formed antibacterial fillers were then mixed into a light-curable glass-ionomer cement formulation. Surface hardness and bacterial viability were used to evaluate the modified cements. Effects of coated furanone moiety content on the modified fillers, modified alumina filler particle size and loading, and total glass filler content were investigated. Results showed that increasing antibacterial furanone content, modified particle size and loading, and total glass filler content generally increased surface hardness. Increasing furanone moiety, filler loading and total filler content increased antibacterial activity. On the other hand, increasing particle size decreased antibacterial activity. The leaching tests indicate that the modified experimental cement showed no leachable antibacterial component to bacteria and cells

An investigation on antibacterial filler property of silver nanoparticles generated from Walnut shell powder by insitu process

Walnut Shell Powder (WNSP) was immersed in 5 (milli Molar) mM Silver Nitrate solution. The solutions were maintained at 80 0C for a day to ensure in-situ generation of silver nanoparticles with the aid of the one step hydrothermal method. The modified WNSP had spherical AgNPs with an average size of 85 nm. FTIR showed some structural variations in both the unchanged and changed WNSP. X-ray diffraction (XRD) results confirmed the formation of in-situ generation of silver nanoparticles in the modified WNSP. Antibacterial studies have showed that there are no inhibition zones formed on WNSP. But in modified WNSP shown the excellent inhibition against both gram negative and gram positive bacteria’s. The zone of inhibition formed against bacteria ranging from 11 mm to 18 mm in diameter. Hence, modified WNSP acts as a low cost filler when making polymer composites for medical and food packing applications.

Synthesis of an anti-cariogenic experimental dental composite containing novel drug-decorated copper particles

Secondary caries is one of the most major cause for re-placement of dental composite restorations. Targeting the survival of cariogenic bacteria residing on the restoration surface may reduce this problem. The present study aims to evaluate the antibacterial potential as well as assess the physical and chemical properties of experimental dental composites containing novel drug-decorated copper particles (DDCP) as adjunct antibacterial filler particles. These were incorporated at concentrations of 0%, 0.5%, 0.10%, 0.20%, and 0.25% (w/w) into experimental composite consisting of methacrylate monomers and silanized silica fillers. RESULTS: Direct contact test revealed that the anti-cariogenic potential of experimental composites was more than the control groups. The cell viability assay showed no toxic effect on MC3T3-E1 cell lines in the MTT assay. The microhardness of experimental composites increased as the percentage of DDCP increased, however, the degree of cure was increased only up till the concentration of 0.20%. The release kinetics of the composites reveals that even after 28days there was a steady and slow release of copper particles signifying the sustained anti-cariogenic effect. CONCLUSION: The experimental composites have good anti-cariogenic potential, which was sustained for one month without any deleterious effect on the physical and chemical properties of resin dental composites.

Nanocomposite egg shell powder with in situ generated silver nanoparticles using inherent collagen as reducing agent

Silver nanoparticles (AgNPs) were in situ generated in poultry hen egg shell powder (ESP) by one step thermal assisted method using the inherently present collagen as a reducing agent. The nanocomposite egg shell powder (NCESP) with in situ generated silver nanoparticles was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and antibacterial tests. The prepared NCESP had the spherical AgNPs in the size range of 50–120 nm with most of them from 81 nm to 90 nm. Further, the average size of the AgNPs generated in the NCESP was 88 nm. The X-ray analysis indicated the presence of both AgNPs and AgO nanoparticles (AgONPs) in the NCESP. The possible mechanism of generation of AgNPs and AgONPs in the NCESP was also proposed. The thermal stability of the NCESP was found to be higher than that of the ESP. The NCESP exhibited excellent antibacterial activity against both the Gram negative and positive bacteria. The NCESP made from poultry waste ESP can be utilized as a low-cost antibacterial cleaning powder for house ware and also as low-cost antibacterial filler in polymer matrices to make antibacterial hybrid nanocomposites.

Physicochemical and biological assessment of flowable resin composites incorporated with farnesol loaded halloysite nanotubes for dental applications

The aim of this study was to fabricate flowable resin composites, by incorporating Farnesol loaded Halloysite Nanotubes (Fa-HNT) as a filler and evaluate their physicochemical as well as biological properties. Chemical and morphological characterization of antibacterial filler, Fa-HNT were performed using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM). The antibacterial filler was mixed into composite material consisting of methacrylate monomers and dental glass fillers at concentrations of 1–20% (wt./wt.). It was observed that addition of mass fractions of Fa-HNT causes enhancement of compressive strength as well as flexural modulus of the composite. However, it significantly decreases flexural strength and degree of conversion. A significant antibacterial activity of dental composite was observed with increase in the area of zone of inhibition against the strains of Streptococcus mutans (S. mutans). There was no cytotoxicity observed by Fa-HNT resin composites on NIH-3T3 (mouse embryonic fibroblast cells) cell lines. A favourable integration of antibacterial filler with significant mechanical properties was achieved at concentrations from 7 to 13 wt% of Fa-HNT in dental composites, which is desirable in dentistry.