Retraction notice to "Titanium and titanium alloys in dentistry: Current trends, recent developments, and future prospects" [Heliyon 8 (2022) e11300]".

[This retracts the article DOI: 10.1016/j.heliyon.2022.e11300.].

Unleashing the promise of emerging nanomaterials as a sustainable platform to mitigate antimicrobial resistance.

The emergence and spread of antibiotic-resistant (AR) bacterial strains and biofilm-associated diseases have heightened concerns about exploring alternative bactericidal methods. The WHO estimates that at least 700 000 deaths yearly are attributable to antimicrobial resistance, and that number could increase to 10 million annual deaths by 2050 if appropriate measures are not taken. Therefore, the increasing threat of AR bacteria and biofilm-related infections has created an urgent demand for scientific research to identify novel antimicrobial therapies. Nanomaterials (NMs) have emerged as a promising alternative due to their unique physicochemical properties, and ongoing research holds great promise for developing effective NMs-based treatments for bacterial and viral infections. This review aims to provide an in-depth analysis of NMs based mechanisms combat bacterial infections, particularly those caused by acquired antibiotic resistance. Furthermore, this review examines NMs design features and attributes that can be optimized to enhance their efficacy as antimicrobial agents. In addition, plant-based NMs have emerged as promising alternatives to traditional antibiotics for treating multidrug-resistant bacterial infections due to their reduced toxicity compared to other NMs. The potential of plant mediated NMs for preventing AR is also discussed. Overall, this review emphasizes the importance of understanding the properties and mechanisms of NMs for the development of effective strategies against antibiotic-resistant bacteria.

Synthesis, Properties, Applications, and Future Prospective of Cellulose Nanocrystals.

The exploration of nanocellulose has been aided by rapid nanotechnology and material science breakthroughs, resulting in their emergence as desired biomaterials. Nanocellulose has been thoroughly studied in various disciplines, including renewable energy, electronics, environment, food production, biomedicine, healthcare, and so on. Cellulose nanocrystal (CNC) is a part of the organic crystallization of macromolecular compounds found in bacteria's capsular polysaccharides and plant fibers. Owing to numerous reactive chemical groups on its surface, physical adsorption, surface grating, and chemical vapor deposition can all be used to increase its performance, which is the key reason for its wide range of applications. Cellulose nanocrystals (CNCs) have much potential as suitable matrices and advanced materials, and they have been utilized so far, both in terms of modifying and inventing uses for them. This work reviews CNC's synthesis, properties and various industrial applications. This review has also discussed the widespread applications of CNC as sensor, acoustic insulator, and fire retardant material.

Nonlinear optical phase shift in blood plasmas for neoplasia diagnosis.

Detecting cancer at an early stage is crucial for timely treatment and better chances of survival. This research focuses on a scanning method for detecting cancer by examining the nonlinear optical characteristics of blood plasma samples. The study used both cancerous and noncancerous plasma samples and presented the results statistically by utilizing an incident laser power-dependent nonlinear optical phase shift variable called ζ in the Z-scan technique. The results showed a clear difference between the cancerous and non-cancerous samples with an accuracy of 92%. Furthermore, the study suggests the potential for measuring the cancer staging from the cancerous plasma. The study also confirmed a significant difference in ζ for plasma samples undergoing chemotherapy. A red laser with high power (above 18mW) was used to avoid the involvement of fluorophores or other chemical reagents in the plasma samples during the measurement.

Collagen/Nigella sativa/chitosan inscribed electrospun hybrid bio-nanocomposites for skin tissue engineering.

The sophisticated new tissue regeneration focused on nanocomposite with different morphologies achieved through advanced manufacturing technology with the inclusion of bio-inscribed materials has piqued the research community's interest. This research aims at developing hybrid bio-nanocomposites with collagen (Col), Nigella sativa (Ns) oil and chitosan (Cs) by a bi-layered green electrospinning on polyvinyl chloride (PVA) layer in a different ratio for tissue regeneration. Fiber morphologies through scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), moisture management, tensile test, antibacterial activity, cell cytotoxicity and wound healing through rabbit model of the fabricated hybrid bio-nanocomposites were investigated. It is worth noting that water-soluble Col (above 60% solution) does not form Taylor cones during electrospinning because unable to overcome the surface tension of the solution (viscosity) to form fibers. The results show that water soluble Col (50% solution) to Cs (25% solution) and Ns (25% solution) has good fiber formation with mean diameter 384 ± 27 nm and degree of porosity is 79%. The fast-absorbing and slow-drying hybrid bio-nanocomposites maintain a moist environment for wounds and allowing gaseous exchange for cell migration and proliferation by the synergistic effects of bio-polymers. All of the biopolymers in bio-nanocomposite improve the H-bonds, which accounts for enough tensile strength to withstand cell pulling force. The antibacterial ZOI concentrations against S. aureus and E. coli were 10 and 8 mm, respectively, which appeared to be sufficient to inhibit bacterial action with 100% cell viability (cytotoxicity). The synergistic effects of Ns and Cs improve tissue regeneration, while native Col improves antibacterial activity, and the rabbit model achieves approximately 84% wound closure in only 10 days, which is 1.5 times faster than the control model. So, the fabricated hybrid bio-composites may be useful for skin tissue engineering.

Fabrication of bio-inscribed (green) electrospun hybrid bio-nanocomposite by the novel bi-layer techniqueThe developed complex (fast absorbing and slow drying composite) absorbs exudate from the wound to provide a suitable moist environment for healing and tissue regenerationAntibacterial susceptibility is boosted by the synergistic effects of Nigella sativa and chitosan, while tissue regeneration is improved (approx. 10 days for rabbit model) by native collagen with no cytotoxicityWater soluble collagen (above 60% solution) will not produce fibers as unable to surmount the surface tension of the solution (viscosity) and increasing amount of Nigella sativa decrease the inhibition zone against gram-negative bacteria [Figure: see text].

Titanium and titanium alloys in dentistry: current trends, recent developments, and future prospects.

Many implant materials have been used in various dental applications depending on their efficacy and availability. A dental implant must possess the required characteristics, such as biocompatibility, corrosion & wear resistance, adequate mechanical properties, osseointegration, etc., to ensure its safe and optimum use. This review analyzes various aspects of titanium (Ti) and Ti alloys, including properties, manufacturing processes, surface modifications, applications as dental implants, and limitations. In addition, it also presents a perception of recent advances in Ti-based implant materials and the futuristic development of innovative dental implants.

Electrospinning of Biomedical Nanofibers/Nanomembranes: Effects of Process Parameters.

Nanotechnology has attracted great attention from researchers in modern science because nanomaterials have innovative and superior physical, chemical, and biological properties, and they can be altered and modified accordingly. As particles get smaller, their surface area increases compared to their volume. Electrospinning is one of the advanced techniques to produce ultrathin nanofibers and membranes, and it is one of the best ways to create continuous nanomaterials with variable biological, chemical, and physical properties. The produced fibers can be utilized in various domains such as wound dressing, drug release, enzyme immobilization, etc. This review examines the biomedical nanofibers/membranes produced by electrospinning techniques to investigate the effects of process parameters (e.g., solution characteristics, applied voltage, and ambient conditions) on nanofiber characteristics (physical, chemical, and mechanical properties). The solution parameters like (i) optimum concentration, (ii) higher molecular weight, and (iii) higher conductivity produce uniform nanofibers, smoother nanofibers, and a smaller and more uniform fiber diameter, respectively. In addition, process parameters such as (i) higher voltage and (ii) slower flow rate produce more polymer ejection from the nozzle and enhance the smoother fiber production, respectively. The optimum tip-to-collector distance is considered to be 13-15 cm. The ambient conditions such as (i) higher humidity and (ii) higher temperature produce thicker and thinner nanofibers, respectively. The controlled parameters through optimization process determine the size and quality of the fibers. The effects of each parameter are discussed in this review. The applications of nanofibers are also discussed.

Face Masks to Combat Coronavirus (COVID-19)-Processing, Roles, Requirements, Efficacy, Risk and Sustainability.

Increasingly prevalent respiratory infectious diseases (e.g., COVID-19) have posed severe threats to public health. Viruses including coronavirus, influenza, and so on can cause respiratory infections. A pandemic may potentially emerge owing to the worldwide spread of the virus through persistent human-to-human transmission. However, transmission pathways may vary; respiratory droplets or airborne virus-carrying particles can have a key role in transmitting infections to humans. In conjunction with social distancing, hand cleanliness, and other preventative measures, the use of face masks is considered to be another scientific approach to combat ubiquitous coronavirus. Different types of face masks are produced using a range of materials (e.g., polypropylene, polyacrylonitrile, polycarbonate, polyurethane, polystyrene, polyester and polyethylene) and manufacturing techniques (woven, knitted, and non-woven) that provide different levels of protection to the users. However, the efficacy and proper disposal/management of the used face masks, particularly the ones made of non-biodegradable polymers, pose great environmental concerns. This review compiles the recent advancements of face masks, covering their requirements, materials and techniques used, efficacy, challenges, risks, and sustainability towards further enhancement of the quality and performance of face masks.

Fabrication, Characterization and In Vitro Assessment of Laevistrombus canarium-Derived Hydroxyapatite Particulate-Filled Polymer Composite for Implant Applications.

This paper presents the formulation, characterization, and in vitro studies of polymer composite material impregnated with naturally derived hydroxyapatite (HA) particulates for biomedical implant applications. Laevistrombus canarium (LC) seashells (SS) were collected, washed and cleaned, sun-dried for 24 h, and ground into powder particulates. The SS particulates of different weight percentages (0, 10, 20, 30, 40, 50 wt%)-loaded high-density polyethylene (HDPE) composites were fabricated by compression molding for comparative in vitro assessment. A temperature-controlled compression molding technique was used with the operating pressure of 2 to 3 bars for particulate retention in the HDPE matrix during molding. The HDPE/LC composite was fabricated and characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), differential scanning calorimetry (DSC), and TGA. Mechanical properties such as tensile, compression, flexural, hardness, and also surface roughness were tested as per ASTM standards. Mass degradation and thermal stability of the HDPE/LC composite were evaluated at different temperatures ranging from 10 to 700 °C using thermogravimetric analysis (TGA). The maximum tensile strength was found to be 27 ± 0.5 MPa for 30 wt% HDPE/LC composite. The thermal energy absorbed during endothermic processes was recorded as 71.24 J/g and the peak melting temperature (Tm) was found to be 128.4 °C for the same 30 wt% of HDPE/LC composite specimen. Excellent cell viability was observed during the in vitro biocompatibility study for EtO-sterilized 30 wt% of HDPE/LC composite specimen, except for a report of mild cytotoxicity in the case of higher concentration (50 µL) of the MG-63 cell line. The results demonstrate the potential of the fabricated composite as a suitable biomaterial for medical implant applications.

Accelerated wound closure: Systematic evaluation of cellulose acetate effects on biologically active molecules release from amniotic fluid stem cells.

Despite a lot of intensive research on cell-scaffold interaction, the focus is mainly on the capacity of construct scaffolds to regulate cell mobility, migration, and cytotoxicity. The effect of the scaffold's topographical and material properties on the expression of biologically active compounds from stem cells is not well understood. In this study, the influence of cellulose acetate (CA) on the electrospinnability of gelatin and the roles of gelatin-cellulose acetate (Ge-CA) on modulating the release of biologically active compounds from amniotic fluid stem cells (AFSCs) is emphasized. It was found that the presence of a small amount of CA could provide a better microenvironment that mimics AFSCs' niche. However, a large amount of CA exhibited no significant effect on AFSCs migration and infiltration. Further study on the effect of surface topography and mechanical properties on AFSCs showed that the tailored microenvironment provided by the Ge-CA scaffolds had transduced physical cues to biomolecules released into the culture media. It was found that the AFSCs seeded on electrospun scaffolds with less CA proportions have profound effects on the secretion of metabolic compounds compared to those with higher CA contained and gelatin coating. The enhanced secretion of biologically active molecules by the AFSCs on the electrospun scaffolds was proven by the accelerated wound closure on the injured human dermal fibroblast (HDF) model. The rapid HDF cell migration could be anticipated due to a higher level of paracrine factors in AFSCs media. Our study demonstrates that the fibrous topography and mechanical properties of the scaffold are a key material property that modulates the high expression of biologically active compounds from the AFSCs. The discovery elucidates a new aspect of material functions and scaffolds material-AFSC interaction for regulating biomolecules release to promote tissue regeneration/repair. To the best of our knowledge, this is the first report describing the scaffolds material-AFSC interaction and the efficacy of scratch assays on quantifying the cell migration in response to the AFSCs metabolic products.

Development and Validation of an Early Scoring System for Prediction of Disease Severity in COVID-19 Using Complete Blood Count Parameters.

The coronavirus disease 2019 (COVID-19) after outbreaking in Wuhan increasingly spread throughout the world. Fast, reliable, and easily accessible clinical assessment of the severity of the disease can help in allocating and prioritizing resources to reduce mortality. The objective of the study was to develop and validate an early scoring tool to stratify the risk of death using readily available complete blood count (CBC) biomarkers. A retrospective study was conducted on twenty-three CBC blood biomarkers for predicting disease mortality for 375 COVID-19 patients admitted to Tongji Hospital, China from January 10 to February 18, 2020. Machine learning based key biomarkers among the CBC parameters as the mortality predictors were identified. A multivariate logistic regression-based nomogram and a scoring system was developed to categorize the patients in three risk groups (low, moderate, and high) for predicting the mortality risk among COVID-19 patients. Lymphocyte count, neutrophils count, age, white blood cell count, monocytes (%), platelet count, red blood cell distribution width parameters collected at hospital admission were selected as important biomarkers for death prediction using random forest feature selection technique. A CBC score was devised for calculating the death probability of the patients and was used to categorize the patients into three sub-risk groups: low (<=5%), moderate (>5% and <=50%), and high (>50%), respectively. The area under the curve (AUC) of the model for the development and internal validation cohort were 0.961 and 0.88, respectively. The proposed model was further validated with an external cohort of 103 patients of Dhaka Medical College, Bangladesh, which exhibits in an AUC of 0.963. The proposed CBC parameter-based prognostic model and the associated web-application, can help the medical doctors to improve the management by early prediction of mortality risk of the COVID-19 patients in the low-resource countries.

Recent Advances in Scaffolding from Natural-Based Polymers for Volumetric Muscle Injury.

Volumetric Muscle Loss (VML) is associated with muscle loss function and often untreated and considered part of the natural sequelae of trauma. Various types of biomaterials with different physical and properties have been developed to treat VML. However, much work remains yet to be done before the scaffolds can pass from the bench to the bedside. The present review aims to provide a comprehensive summary of the latest developments in the construction and application of natural polymers-based tissue scaffolding for volumetric muscle injury. Here, the tissue engineering approaches for treating volumetric muscle loss injury are highlighted and recent advances in cell-based therapies using various sources of stem cells are elaborated in detail. An overview of different strategies of tissue scaffolding and their efficacy on skeletal muscle cells regeneration and migration are presented. Furthermore, the present paper discusses a wide range of natural polymers with a special focus on proteins and polysaccharides that are major components of the extracellular matrices. The natural polymers are biologically active and excellently promote cell adhesion and growth. These bio-characteristics justify natural polymers as one of the most attractive options for developing scaffolds for muscle cell regeneration.

Facile one-pot synthesis of heterostructure SnO2/ZnO photocatalyst for enhanced photocatalytic degradation of organic dye.

In this work, heterostructure SnO2/ZnO nanocomposite photocatalyst was prepared by a straightforward one step polyol method. The resulting photocatalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption analyses, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The results showed that the synthesized SnO2/ZnO nanocomposites possessed mesoporous wurtzite ZnO and cassiterite SnO2 nanocrystallites. The photocatalytic activity of the prepared SnO2/ZnO photocatalyst was investigated by the degradation of methylene blue dye under UV light irradiation. The heterostructure SnO2/ZnO photocatalyst showed much higher photocatalytic activities for the degradation of methylene blue dye than individual SnO2, ZnO nanomaterials and reference commercial TiO2 P25. This higher photocatalytic degradation activity was due to enhanced charge separation and subsequently the suppression of charge recombination in the SnO2/ZnO photocatalyst resulting from band offsets between SnO2 and ZnO. Finally, these heterostructure SnO2/ZnO nanocatalysts were stable and could be recycled several times without any appreciable change in degradation rate constant which opens new avenues toward potential industrial applications.

Ultrasound as a noninvasive tool for monitoring reproductive physiology in male Atlantic salmon (Salmo salar).

We examined the potential for ultrasound as a noninvasive tool for maturation monitoring in Atlantic salmon (Salmo salar) males. Ultrasound examination and measurements were compared to common practices for maturation monitoring such as gonadosomatic index (GSI), sex hormone analysis, and histological analysis of spermatogenesis. There were significant correlations (R2  = 0.68, P < 0.01) between ultrasound-based measurements of the left testis and total testes weight and GSI, and ultrasound could be used for noninvasive GSI measurements. Echogenicity of ultrasound images corresponded to the histological stages observed, which added nuance to ultrasound-based GSI measurements during final weeks preceding stripping. We propose that ultrasound can be used as an alternative to more invasive methods for sexual maturation monitoring in wild and farmed Atlantic salmon males. Using ultrasound technology, we have established a quick and noninvasive method that could reduce the number of stressful handlings and unwanted sacrifice of broodfish required for maturation monitoring in Atlantic salmon males.

A facile hydrothermal approach for catalytic and optical behavior of tin oxide- graphene (SnO2/G) nanocomposite.

A cost-effective, facile hydrothermal approach was made for the synthesis of SnO2/graphene (Gr) nano-composites. XRD diffraction spectra clearly confirmed the presence of tetragonal crystal system of SnO2 which was maintaining its structure in both pure and composite materials' matrix. The stretching and bending vibrations of the functional groups were analyzed using FTIR analysis. FESEM images illustrated the surface morphology and the texture of the synthesized sample. HRTEM images confirmed the deposition of SnO2 nanoparticles over the surface of graphene nano-sheets. Raman Spectroscopic analysis was carried out to confirm the in-plane blending of SnO2 and graphene inside the composite matrix. The photocatalytic performance of the synthesized sample under UV irradiation using methylene blue dye was observed. Incorporation of grapheme into the SnO2 sample had increased the photocatalytic activity compared with the pure SnO2 sample. The electrochemical property of the synthesized sample was evaluated.

Current strategies in multiphasic scaffold design for osteochondral tissue engineering: A review.

The repair of osteochondral defects requires a tissue engineering approach that aims at mimicking the physiological properties and structure of two different tissues (cartilage and bone) using specifically designed scaffold-cell constructs. Biphasic and triphasic approaches utilize two or three different architectures, materials, or composites to produce a multilayered construct. This article gives an overview of some of the current strategies in multiphasic/gradient-based scaffold architectures and compositions for tissue engineering of osteochondral defects. In addition, the application of finite element analysis (FEA) in scaffold design and simulation of in vitro and in vivo cell growth outcomes has been briefly covered. FEA-based approaches can potentially be coupled with computer-assisted fabrication systems for controlled deposition and additive manufacturing of the simulated patterns. Finally, a summary of the existing challenges associated with the repair of osteochondral defects as well as some recommendations for future directions have been brought up in the concluding section of this article.

The potential hazards of Aspergillus sp. in foods and feeds, and the role of biological treatment: a review.

The contamination of food and feed by Aspergillus has become a global issue with a significant worldwide economic impact. The growth of Aspergillus is unfavourable to the development of food and feed industries, where the problems happen mostly due to the presence of mycotoxins, which is a toxic metabolite secreted by most Aspergillus groups. Moreover, fungi can produce spores that cause diseases, such as allergies and asthma, especially to human beings. High temperature, high moisture, retarded crops, and poor food storage conditions encourage the growth of mold, as well as the development of mycotoxins. A variety of chemical, biological, and physical strategies have been developed to control the production of mycotoxins. A biological approach, using a mixed culture comprised of Saccharomyces cerevisiae and Lactobacillus rhamnosus resulted in the inhibition of the growth of fungi when inoculated into fermented food. The results reveal that the mixed culture has a higher potential (37.08%) to inhibit the growth of Aspergillus flavus (producer of Aflatoxin) compared to either single culture, L. rhamnosus NRRL B-442 and S. cerevisiae, which inhibit the growth by 63.07% and 64.24%, respectively.

Processing of polycaprolactone and polycaprolactone-based copolymers into 3D scaffolds, and their cellular responses.

Synthetic polymers have attracted much attention in tissue engineering due to their ability to modulate biomechanical properties. This study investigated the feasibility of processing poly(epsilon-caprolactone) (PCL) homopolymer, PCL-poly(ethylene glycol) (PEG) diblock, and PCL-PEG-PCL triblock copolymers into three-dimensional porous scaffolds. Properties of the various polymers were investigated by dynamic thermal analysis. The scaffolds were manufactured using the desktop robot-based rapid prototyping technique. Gross morphology and internal three-dimensional structure of scaffolds were identified by scanning electron microscopy and micro-computed tomography, which showed excellent fusion at the filament junctions, high uniformity, and complete interconnectivity of pore networks. The influences of process parameters on scaffolds' morphological and mechanical characteristics were studied. Data confirmed that the process parameters directly influenced the pore size, porosity, and, consequently, the mechanical properties of the scaffolds. The in vitro cell culture study was performed to investigate the influence of polymer nature and scaffold architecture on the adhesion of the cells onto the scaffolds using rabbit smooth muscle cells. Light, scanning electron, and confocal laser microscopy showed cell adhesion, proliferation, and extracellular matrix formation on the surface as well as inside the structure of both scaffold groups. The completely interconnected and highly regular honeycomb-like pore morphology supported bridging of the pores via cell-to-cell contact as well as production of extracellular matrix at later time points. The results indicated that the incorporation of hydrophilic PEG into hydrophobic PCL enhanced the overall hydrophilicity and cell culture performance of PCL-PEG copolymer. However, the scaffold architecture did not significantly influence the cell culture performance in this study.

Biochemical and imaging alterations of renal bone disease in newly detected predialysis and on maintenance dialysis patients.

Skeletal involvement in chronic kidney disease manifests long before the initiation of dialysis. This study aimed at identifying the extent of renal bone disease among predialysis and on maintenance dialysis patients. Thirty-two patients (Group 1) on maintenance hemodialysis (MHD) for a variable period of time were compared with 20 newly detected irregularly treated advanced renal failure (immediately predialysis), patients (Group 2) for their clinical, biochemical and imaging features. The mean age of Group 1 and Group 2 patients was 45+/-14 vs. 34+/-15 years (p<0.05). Comparison of blood biochemistries between Groups 1 and 2 showed serum creatinine 9.9+/-2.9 vs. 13.4+/-4.4 mg/dL (p<0.01); calcium 10.1+/-1.8 vs. 7.8+/-1.2 mg/dL (p<0.001); phosphate 4.4+/-1.2 vs. 7.9+/-2.1 mg/dL (p<0.001); alkaline phosphatase 116.4+/-31.7 vs. 85.7+/-30.6 IU/L (p<0.05); and parathormone 71.7+/-48.2 vs. 146.9+/-92.1 pg/mL (p<0.05). Radiological changes present in the 2 groups were as follows: osteopenia 63% vs. 65% (ns); trabecular resorption 53% vs. 20% (p<0.05); soft tissue calcification 31% vs. 10% (p<0.05); bone cysts 16% vs. 26% (ns); and subperiosteal bone resorption 16% vs. 20% (ns). Technetium 99 methylene diphosphonate (Tc-99 MDP) bone scans in both groups of patients showed similar increased uptake in wrist joint, tibia-fibula, costochondral junction, vertebral column, sternum, radius-ulna and mandible. X-ray findings were positive for bone involvement in 59% of cases, and Tc-99 scan was positive in 80% (p<0.05). It is concluded that newly detected, irregularly treated patients with advanced renal failure who are predialysis may present with deranged calcium homeostasis and a high prevalence of bone involvement similar to MHD patients.