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Surgical site infections (SSI) are amongst the most common medical infections, occurring in 2 to 4% of patients undergoing a surgical procedure. Smart surgical sutures can play an important role in preventing infection. For example, antimicrobial sutures detectable via clinical imaging modalities can support monitoring wounds post-surgery and enhance patient recovery. However, no commercial suture products possess these properties. Herein, contrasting iodine carbon nanoparticles (ICPs) are synthesized using a solvothermal approach. These ICPs were incorporated into polycaprolactone (PCL) via a coaxial extrusion technique inspired by the "core-shell" multilayered suture structure, which integrates multiple clinically favourable functions into one suture device. This system exhibits high imaging contrast capabilities for real-time imaging even after 22 days in-vitro, with strong antimicrobial properties and a reduction in biofilm formation. The multifunctional and biocompatible suture composite developed in this study shows strong antimicrobial properties and can act as an immobilized marker to monitor the surgical site during and after surgical procedures. Identifying suture integrity and location within the body through minimally invasive methods can alleviate patient discomfort and minimize the risk of infection. publishedVersion

The capacity of an adsorbent to bind and remove dye from solution greatly depends on the type of functionalization present on the nanoparticles surface, and its interaction with the dye molecules. Within this study, nitrogenous silane nanoparticles were hydrothermally synthesized resulting in the formation of rapid and highly efficient adsorbents for concentrated mixed dyes. The amorphous silane nanoparticles exhibited a monolayer based mechanism of mixed dye adsorption with removal capacities between 416.67 and 714.29 mg/g of adsorbent. Dye removal was predominantly due to the electrostatic attraction between the positively charged silane nanoparticles (13.22–8.20 mV) and the negatively charged dye molecules (−54.23 mV). Addition of H. annuus extract during synthesis resulted in three times the surface area and 10 times increased pore volume compared to the positive control. XPS analysis showed that silane treatments had various nitrogen containing functionalities at their surface responsible for binding dye. The weak colloidal stability of silane particles (13.22–8.20 mV) was disrupted following dye binding, resulting in their rapid coagulation and flocculation which facilitated the separation of bound dye molecules from solution. The suitability for environmental applications using these treatments was supported by a bacterial viability assay showing >90% cell viability in treated dye supernatants.

Ultrasmall nanoparticles are often grouped under the broad umbrella term of “nanoparticles” when reported in the literature. However, for biomedical applications, their small sizes give them intimate interactions with biological species and endow them with unique functional physiochemical properties. Carbon quantum dots (CQDs) are an emerging class of ultrasmall nanoparticles which have demonstrated considerable biocompatibility and have been employed as potent theragnostic platforms. These particles find application for increasing drug solubility and targeting, along with facilitating the passage of drugs across impermeable membranes (i.e., blood brain barrier). Further functionality can be triggered by various environmental conditions or external stimuli (i.e., pH, temperature, near Infrared (NIR) light, ultrasound), and their intrinsic fluorescence is valuable for diagnostic applications. The focus of this review is to shed light on the therapeutic potential of CQDs and identify how they travel through the body, reach their site of action, administer therapeutic effect, and are excreted. Investigation into their toxicity and compatibility with larger nanoparticle carriers is also examined. The future of CQDs for theragnostic applications is promising due to their multifunctional attributes and documented biocompatibility. As nanomaterial platforms become more commonplace in clinical treatments, the commercialization of CQD therapeutics is anticipated. publishedVersion

Graphical abstract, Solid or liquid platforms have been traditionally employed for measuring the fluorescent properties of quantum carbon dots (QCD). Hydrogels possess both liquid and solid properties which allow them to overcome several shortfalls of both solid and liquid sensing platforms. Hydrogels offer a three dimensional platform which can house nanoparticles with different attributes (i.e. fluorescent QCD’s) and prevents their aggregation. Here, we incorporate QCD’s (made from the hydrothermal treatment of 1-naphthylamine and citric acid) into the matrix of a zinc oxide hydrogel. This nanocomposite was shown to have hexavalent chromium (Cr6+) specific fluorescence quenching properties. Detailed fluorescence analysis of the hydrogel with Cr6+ was conducted in a high throughput manner by loading the hydrogel into wells of a black 96-well plate. Fluorescence quenching of the hydrogel-QCD-nanocomposites in the presence of dilutions of Cr6+ was measured using a fluorescence spectrophotometer and showed incremental fluorescence decreases with increasing Cr6+ concentration. Furthermore, this was quantitatively confirmed by Stern–Volmer plots showing a linear quenching trend (R2 = 0.9975) when comparing fluorescence intensities against increasing Cr6+ concentrations (0.234–1.875 μM). This technology can be applied for routine water quality testing in agricultural, natural and potable water sources for the early detection of heavy metal pollutants.

Hexavalent chromium is a genotoxic and carcinogenic byproduct of a number of industrial processes, which is discharged into the environment in excessive and toxic concentrations worldwide. In this paper, the synthesis of green iron oxide nanoparticles using extracts of four novel plant species [Pittosporum undulatum, Melia azedarach, Schinus molle, and Syzygium paniculatum (var. australe)] using a "bottom-up approach" has been implemented for hexavalent chromium remediation. Nanoparticle characterizations show that different plant extracts lead to the formation of nanoparticles with different sizes, agglomeration tendencies, and shapes but similar amorphous nature and elemental makeup. Hexavalent chromium removal is linked with the particle size and monodispersity. Nanoparticles with sizes between 5 and 15 nm from M. azedarach and P. undulatum showed enhanced chromium removal capacities (84.1-96.2%, respectively) when compared to the agglomerated particles of S. molle and S. paniculatum with sizes between 30 and 100 nm (43.7-58.7%, respectively) in over 9 h. This study has shown that the reduction of iron salts with plant extracts is unlikely to generate vast quantities of stable zero valent iron nanoparticles but rather favor the formation of iron oxide nanoparticles. In addition, plant extracts with higher antioxidant concentrations may not produce nanoparticles with morphologies optimal for pollutant remediation.

Urban soils in many communities in the United States and internationally have been contaminated by lead (Pb) from past use of lead additives in gasoline, deterioration of exterior paint, emissions from Pb smelters and battery recycling and other industries. Exposure to Pb in soil and related dust is widespread in many inner city areas. Up to 20–40% of urban children in some neighborhoods have blood lead levels (BLLs) equal to or above 5 μg per decilitre, the reference level of health concern by the U.S. Centers for Disease Control. Given the widespread nature of Pb contamination in urban soils it has proven a challenge to reduce exposure. In order to prevent this exposure, an evidence-based approach is required to isolate or remediate the soils and prevent children and adult's ongoing exposure. To date, the majority of community soil Pb remediation efforts have been focused in mining towns or in discrete neighborhoods where Pb smelters have impacted communities. These efforts have usually entailed very expensive dig and dump soil Pb remediation techniques, funded by the point source polluters. Remediating widespread non-point source urban soil contamination using this approach is neither economical nor feasible from a practical standpoint. Despite the need to remediate/isolate urban soils in inner city areas, no deliberate, large scale, cost effective Pb remediation schemes have been implemented to isolate inner city soils impacted from sources other than mines and smelters. However, a city-wide natural experiment of flooding in New Orleans by Hurricane Katrina demonstrated that declines in soil Pb resulted in major BLL reductions. Also a growing body of literature of smaller scale pilot studies and programs does exist regarding low cost efforts to isolate Pb contaminated urban soils. This paper reviews the literature regarding the effectiveness of soil Pb remediation for reducing Pb exposure and BLL in children, and suggests best practices for addressing the epidemics of low-level Pb poisoning occurring in many inner city areas.

Nanotechnology is playing an increasingly important role in addressing innovative and effective solutions to a vast range of environmental challenges. In recent years, nanoscale zero valent iron (nZVI), carbon nanotubes and nano-fibers have been applied for the remediation of a variety of contaminants including chlorinated compounds, hydrocarbons, organic compounds and heavy metals. The use and development of nanomaterials (NMs) are understandably heralded as an environmentally beneficial technology; however the ecological risks associated with their use have only begun to be assessed. This critical review highlights (i) the successful applications of nanotechnology for environmental clean-up, (ii) the potential ecological implications of environmental nanotechnology (E-Nano) involving use of nanomaterials and (iii) the potential solutions to current E-Nano related implications. Although there is undoubtedly cause for concerns among the scientific community over nanotechnology risk management, the efficacy of E-Nano is unquestionable. Hence, to advance this field in a rational manner without causing further environmental damage, we suggest an integrated preventive approach. This includes innovative greener routes for nanoparticle synthesis; advanced engineering ways for manufacturing smarter and more degradable NMs; and governing local and international legislations to monitor nanoparticles released into the environment. The aims of these recommendations is to promote the responsible innovation of NMs and its cautious use in order to take optimal advantage of E-Nano, minimizing potential risks which is a crucial aspect to improve environmental quality rather than to cause additional damage.

Biocompatible carbon quantum dots (CQDs) have recently attracted increased interest in biomedical imaging owing to their advantageous photoluminescence properties. Numerous precursors of fluorescent CQDs and various fabrication procedures are also reported in the literature. However, the use of concentrated mineral acids and other corrosive chemicals during the fabrication process curtails their biocompatibility and severely limits the utilization of the products in cell bio-imaging. In this study, a facile, fast, and cost-effective synthetic route is employed to fabricate CQDs from a natural organic resource, namely bread, where the use of any toxic chemicals is eliminated. Thus, the novel chemical-free technique facilitated the production of luminescent CQDs that were endowed with low cytotoxicity and, therefore, suitable candidates for bioimaging sensors. The above mentioned amorphous CQDs also exhibited fluorescence over 360&ndash, 420 nm excitation wavelengths, and with a broad emission range of 360&ndash, 600 nm. We have also shown that the CQDs were well internalized by muscle myoblasts (C2C12) and differentiated myotubes, the cell lines which have not been reported before.