Biomineralized fluorocanasite-reinforced biocomposite scaffolds demonstrate expedited osteointegration of critical-sized bone defects.

The development of patient-specific bone scaffolds that can expedite bone regeneration has been gaining increased attention, especially for critical-sized bone defects or fractures. Precise adaptation of the scaffold to the region of implantation and reduced surgery times are also crucial at clinical scales. To this end, bioactive fluorcanasite glass-ceramic microparticulates were incorporated within a biocompatible photocurable resin matrix following which the biocomposite resin precursor was 3D-printed with digital light processing method to develop the bone scaffold. The printing parameters were optimized based on spot curing investigation, particle size data, and UV-visible spectrophotometry. In vitro cell culture with MG-63 osteosarcoma cell lines and pH study within simulated body fluid demonstrated a noncytotoxic response of the scaffold samples. Further, the in vivo bone regeneration ability of the 3D-printed biocomposite bone scaffolds was investigated by implantation of the scaffold samples in the rabbit femur bone defect model. Enhanced angiogenesis, osteoblastic, and osteoclastic activities were observed at the bone-scaffold interface, while examining through fluorochrome labelling, histology, radiography, field emission scanning electron microscopy, and x-ray microcomputed tomography. Overall, the results demonstrated that the 3D-printed biocomposite bone scaffolds have promising potential for bone loss rehabilitation.

An in vivo toxicity assessment of piezoelectric sodium potassium niobate [NaxK1-xNbO3 (x = 0.2-0.8)] nanoparticulates towards bone tissue engineering approach.

One of the recent challenges in the design/development of prosthetic orthopedic implants is to address the concern of local/systemic toxicity of debris particles, released due to wear or degradation. Such debris particles often lead to inflammation at the implanted site or aseptic loosening of the prosthesis which results in failure of the implant during long run. Several in vitro studies demonstrated the potentiality of piezoelectric sodium potassium niobate [NaxK1-xNbO3 (x = 0.2, 0.5, 0.8), NKN] as an emerging next-generation polarizable orthopedic implant. In this perspective, we performed an in vivo study to examine the local and systemic toxicity of NKN nanoparticulates, as a first report. In the present study, male Wistar rats were intra-articularly injected to the knee joint with 100 µl of NKN nanoparticulates (25 mg/ml in normal saline). After 7 days of exposure, the histopathological analyses demonstrate the absence of any inflammation or dissemination of nanoparticulates in vital organs such as heart, liver, kidney and spleen. The anti-inflammatory cytokines (IL-4 and IL-10) profile analyses suggest the increased anti-inflammatory response in the treated rats as compared to non-injected (control) rats, preferably for the sodium and potassium rich NKN i.e., Na0.8K0.2NbO3 and Na0.2K0.8NbO3. The biochemical analyses revealed no pathological changes in the liver and kidney of particulate treated rats. The present study is the first proof to confirm the non-toxic nature of NKN nanoparticulates which provides a step forward towards the development of prosthetic orthopedic implants using biocompatible piezoelectric NKN ceramics.

Interplay of surface polarization charge, dynamic electrical stimulation and compositional modification towards accelerated osteogenic response of NaxK1-xNbO3 piezo-bioceramics.

Bone remodeling processes involve endogenous bioelectrical signals such as piezoelectric charges. Moreover, external electrical stimulation helps in improving the healing capability of injured tissues by modulating the metabolic signaling pathways of cells. Towards this end, the present study reveals the influence of the combined action of electrostatic surface polarization charge and dynamic pulsed electrical stimulation alongwith compositional modification towards improving the osteogenic response of emerging piezo-bioceramics, sodium potassium niobate [NaxK1-xNbO3 (x = 0.2-0.8), NKN]. The dependence of crystal structure on compositions (x) was retrieved by Rietveld refinement and X-ray peak profile analyses. The surface charge, stored in the polarized (@ 25 kV at 500 °C) NaxK1-xNbO3 (x = 0.2, 0.5, 0.8) samples were measured to be 0.52, 0.50 and 0.47 µC/cm2, respectively, using thermally stimulated depolarized current (TSDC). X-ray photoelectron spectroscopy (XPS) survey scan spectra revealed that the polarization process does not alter the surface chemistry of NKN. Negatively charged surfaces are observed to accelerate early-stage adhesion of osteoblast-like cells which further results in enhanced spreading of adhered cells. Subsequently, the dynamic pulsed electrical stimulation of 1 V/cm with the pulse duration of 400 µs was applied, while the cells were being adhered on electrostatically charged surfaces. The quantitative and qualitative analyses revealed that the synergistic action of electrostatic surface polarization charge and dynamic pulsed electrical stimulation further accelerates cell proliferation and differentiation on negatively charged surfaces of Na and K-rich compositions of NKN. The mechanism of augmented cellular activity was analyzed using intracellular Ca2+ measurement.

Retrospection of Nonlinear Adaptive Algorithm-Based Intelligent Plane Image Interaction System.

This paper introduces the application and classification of an adaptive filtering algorithm in the image enhancement algorithm. And the filtering noise reduction impact is compared using MATLAB software for programming, image processing, LMS algorithm, RLS algorithm, histogram equalisation algorithm, and Wiener filtering method filtering noise reduction effect. To optimize the intelligent graphic image interaction system, the proposed nonlinear adaptive algorithm of intelligent graphic image interaction system research is based on the digital filter and adaptive filtering algorithm for simulation experiment. The experimental results of several noise index data filtering algorithms show that the fuzzy coefficient k of LMS index is 0.86, RLS index is 0.91, the histogram equalization index is 0.53, and the Wiener filtering index is 0.62. LMS index of quality index Q is 0.90, RLS index is 0.95, histogram equalization index is 0.58, Wiener filtering index is 0.65. According to the above results, comparing LMS with the RLS method and according to SNR, k, and Q values in the simulation results in the process of processing, it is found that the convergence speed of the RLS algorithm is obviously better than that of the LMS algorithm, and the stability is also good. Additionally, the differential imaging data can provide a strong reference for the clinical diagnosis and qualitative differentiation of TBP and CP, and MSCT is worthy of extensive application in the clinical diagnosis of peritonitis. The processing effect of the image with high similarity to the original image is greatly improved compared with the histogram equalization and Wiener filtering methods used in the simulation.

Assessment of the spatial-temporal distribution of groundwater recharge in data-scarce large-scale African river basin.

The systematic assessment of spatial and temporal distribution of groundwater recharge (GWR) is crucial for the sustainable management of the water resources systems, especially in large-scale river basins. This helps in identifying critical zones in which GWR largely varies and thus leads to negative consequences. However, such analyses might not be possible when the models require detailed hydro-climate and hydrogeological data in data-scarce regions. Hence, this calls for alternate suitable modeling approaches that are applicable with the limited data and, however, includes the detailed assessment of the spatial-temporal distribution of different water balance components especially the GWR component. This paper aimed at investigating the spatial and temporal distribution of the GWR at monthly, seasonal and annual scales using the WetSpass-M physically distributed hydrological model, which is not requiring the detailed catchment information. In addition, the study conducted the sensitivity analysis of model parameters to assess the significant variation of GWR. The large-scale river basins such as the Omo river basin, Ethiopia, were chosen to demonstrate the potential of the WetSpass-M model under limited data conditions. From the modeling results, it was found that the maximum average monthly GWR of 13.4 mm occurs in July. The estimated average seasonal GWR is 32.5 mm/yr and 47.6 mm/yr in the summer and winter seasons, respectively. Further, it was found that GWR is highly sensitive to the parameter such as average rainfall intensity factor.

Recent advances in materials science: a reinforced approach toward challenges against COVID-19.

With the recent COVID-19 pandemic, medical professionals and scientists have encountered an unprecedented trouble to make the latest technological solutions to work. Despite of abundant tools available as well as initiated for diagnosis and treatment, researchers in the healthcare systems were in backfoot to provide concrete answers to the demanding challenge of SARS-CoV-2. It has incited global collaborative efforts in every field from economic, social, and political to dedicated science to confront the growing demand toward solution to this outbreak. Field of materials science has been in the frontline to the current scenario to provide major diagnostic tools, antiviral materials, safety materials, and various therapeutic means such as, antiviral drug design, drug delivery, and vaccination. In the present article, we emphasized the role of materials science to the development of PPE kits such as protecting suits, gloves, and masks as well as disinfection of the surfaces/surroundings. In addition, contribution of materials science towards manufacturing diagnostic devices such as microfluidics, immunosensors as well as biomaterials with a point of care analysis has also been discussed. Further, the efficacy of nanoparticles and scaffolds for antiviral drug delivery and micro-physiological systems as well as materials derived from human tissues for extracorporeal membrane oxygenation (ECMO) devices have been elaborated towards therapeutic applications.

Electrical stimulation and piezoelectric biomaterials for bone tissue engineering applications.

Bioelectrical phenomenon in natural bone has been well recognized for its role in bone development and fracture healing. For example, the piezoelectricity induced modulation in cellular functionality assists in the repair and regeneration of bone tissue. Against this backdrop, we review here the origin of dielectric and electrical responses (piezo-, pyro- and ferro-electricity) of natural bone along with their consequences in regulating the bone metabolic activities. The concept of piezoelectricity induced osteogenesis has driven the development of piezoimplants for bone regeneration applications. A number of recent studies have been critically analyzed to demonstrate as to how the surface charge polarization or electric field stimulation together with functional properties of piezoelectric biomaterials can synergistically modulate cell functionality, in vitro or tissue regeneration, in vivo. The examples are drawn from a range of piezoelectric bioceramics, (e.g. barium titanate, magnesium silicate etc.) and biopolymers (e.g. polyvinylidene fluoride (PVDF), collagen, etc). The challenging problem of processing the compositionally tailored bioceramics is emphasized in particular reference to (Na, K)NbO3, an implantable biomaterial with the most attractive combination of piezoresponsive properties. Taken together, this review comprehensively emphasizes the appealing relevance of piezo-bioceramics and piezo-biopolymers as next-generation orthopedic biomaterials.

Development of luminescent atacamite nanoclusters for bioimaging and photothermal applications.

Fluorescent atacamite nanoclusters (FANCs) have been developed and modified with silica for Drosophila salivary gland tissue imaging and photothermally induced cell death of osteosarcoma MG-63 cells. FANCs were synthesized with Moringa oleifera leaf extract without using any hazardous reducing and external capping agents. FANC was further used to evaluate light absorption, fluorescence emission, band gap, and magnetic properties as the first report on such nanoclusters. Upon excitation with a 350 nm light source, FANCs exhibited fluorescence at 460 nm, with a relative quantum yield of 0.3%. Besides, silica-encapsulated fluorescent atacamite nanoclusters (SEFANC) manifested remarkable improvement in emission, quantum yield (1.7%), shelf-life (15 d), biocompatibility, and photostability. Concomitantly, it has also increased the absorption in the near-infrared region and demonstrated high heat generation potential (42 °C → 50 °C). The above results suggest that FANC can be a potential candidate in the area of nanomedicine for a number of applications such as bioimaging, photothermal therapy, etc.

Past, present and future land use changes and their impact on water balance.

Landuse change influences the water balance of a region affecting the available water along with the change in the evapotranspiration (ET). The major objectives of this study are to assess the landuse change and its impact on the water balance of the study area, which is a part of the Narmada river basin in Madhya Pradesh, India. Landuse changes of 1990, 2000 and 2011 have been analyzed and the Markov Chain model has been used to predict decadal change of 2020, 2030, 2040 and 2050 landuse. The influence of the past, present and future landuse change on water balance has been analyzed with the SWAT (Soil and Water Analysis Tool) model in the study area. The effect of changes are shown in 12 different sub-watersheds of the area, reflecting an increased water yield (runoff, including ground-water outflow) and surface runoff but decreased ET, which is due to change in the curve number (CN) values (79.85 in 1990 to 84.63 in 2050). Increased CN value in different sub-watersheds of the region has been observed due to a reduction in the vegetation areas, and increase in the agricultural land and settlements. This has caused an increased runoff and decreased ET. The water yield has increased by 6.98% from 1990 to 2011 (1.92 CN increase) and by 17.5% as projected in the 2050 (4.78 CN increase). The actual ET decreases by 3.37% from 1990 to 2011 and by 8.40% in 2050. Simulation with the SWAT using landuse change showed reduction in ET and increased runoff in different sub-watersheds, which needs to be considered in terms of management.

Synthesis and in vitro study of novel Mannich bases as antibacterial agents.

A series of novel Mannich bases derived from 5-chloro-2-methoxybenzamide and sulfonamides/amines have been synthesised and the antibacterial activities were evaluated against various Gram positive and Gram negative strains of bacteria. Some of the synthesized compounds showed superior in vitro activities as compared to their parent sulfonamides.