Ananya Barui

ROS generation by reduced graphene oxide (rGO) induced by visible light showing antibacterial activity: comparison with graphene oxide (GO)

Reduced graphene oxide (rGO) generates reactive oxygen species (ROS) under visible light in air via a singlet oxygen–superoxide anion radical pathway which readily kills Enterobacter sp. The rGO+ intermediate reacts with a hydroxyl ion to produce graphene oxide (GO) as a coating on the surface of rGO resulting in enhanced fluorescence and a slow down in photo-induced ROS formation. GO is not toxic but on ageing it gets a surface coating of rGO and shows toxicity.

Honey dilution impact on in vitro wound healing: Normoxic and hypoxic condition

Honey is known as a popular healing agent against tropical infections and wounds. However, the effects of honey dilutions on keratinocyte (HaCaT) wound healing under hypoxic condition is still not explored. In this study, we examined whether honey dilution have wound healing potential under hypoxic stress. The antioxidant potential and healing efficacy of honey dilution on in vitro wound of human epidermal keratinocyte (HaCaT cells) under hypoxia (3% O2), and normoxia is explored by nitro blue tetrazolium assay. The cell survival % quantified by MTT assay to select four honey dilutions like 10, 1, 0.1, and 0.01 v/v% and the changes in cellular function was observed microscopically. Further, the cell proliferation, migration, cell–cell adhesion, and relevant gene expression were studied by flow cytometry, migration/scratch assay, immunocytochemistry, and reverse transcription‐polymerase chain reaction, respectively. The expression pattern of cardinal molecular features viz. E‐cadherin, cytoskeletal protein F‐actin, p63, and hypoxia marker Hif 1α were examined. Honey dilution in 0.1% v/v combat wound healing limitations in vitro under normoxia and hypoxia (3%). Its wound healing potential was quantified by immunocytochemistry and real‐time PCR for the associated molecular features that were responsible for cell proliferation and migration. Our data showed that honey dilution can be effective in hypoxic wound healing. Additionally, it reduced superoxide generation and supplied favorable bioambience for cell proliferation, migration, and differentiation during hypoxic wound healing. These findings may reveal the importance of honey as an alternative and cost effective therapeutic natural product for wound healing in hypoxic condition.

Nano-patterned honey incorporated silk fibroin membranes for improving cellular compatibility

The desirable properties of a matrix for tissue engineering applications appears to shift from a minimal model of supporting cell growth to a more inclusive role as a matrix to trigger the regeneration process. This requirement has propelled efforts towards bio-functionalization of matrices both by chemical and textural modification of most advanced materials, including silk. Amongst different biomaterials, silk fibroin (SF) has been extensively used for various tissue engineering applications, because of its low immunogenicity and good mechanical strength, although low biological activity and a poor biodegradability rate has remained its major limitation for use in regenerative medicine. In the present study, the physical as well as biological properties of SF have been improved by incorporation of honey, a natural healing agent. Honey-blended SF films (HSF) demonstrated increased mechanical strength together with enhanced wettability, swelling ability and degradability without hampering the original mechanical and biological properties of both honey and SF. In addition, parallel-aligned nanostructures were produced over native SF and HSF using soft lithography to form two-dimensional nano-patterned membranes. HSF films demonstrated enhanced surface roughness in flat membranes and even more so in nano-patterned membranes when compared with native SF membranes which are essential for cellular adhesion and proliferation. Furthermore, biocompatibility and cellular behavior such as adhesion, proliferation, spreading and interaction of 3T3 fibroblast cells were improved using HSF when compared with using native SF membranes. Thus, HSF membranes with enhanced bio-physical properties are a potential material for use in regenerative medicine and tissue engineering applications.

Epithelial mesenchymal transition in lung cancer cells: A quantitative analysis.

Cellular auto-fluorescence along with morphological and cytoskeletal features were assessed in lung cancer cells undergoing induced epithelial mesenchymal transition (EMT). During EMT progression, significant increase was observed in cellular aspect ratio (AR), filamentous (F)-actin and green auto-fluorescence intensities while blue intensity decreased. These features were provided to a kernel classification framework. The classification accuracy were impressive, thus these features along with the classification technique can be considered as suitable tools for automated grading of lung cancer cells undergoing EMT progression.

Essential steps in bioprinting: From pre- to post-bioprinting

An increasing demand for directed assembly of biomaterials has inspired the development of bioprinting, which facilitates the assembling of both cellular and acellular inks into well-arranged three-dimensional (3D) structures for tissue fabrication. Although great advances have been achieved in the recent decade, there still exist issues to be addressed. Herein, a review has been systematically performed to discuss the considerations in the entire procedure of bioprinting. Though bioprinting is advancing at a rapid pace, it is seen that the whole process of obtaining tissue constructs from this technique involves multiple-stages, cutting across various technology domains. These stages can be divided into three broad categories: pre-bioprinting, bioprinting and post-bioprinting. Each stage can influence others and has a bearing on the performance of fabricated constructs. For example, in pre-bioprinting, tissue biopsy and cell expansion techniques are essential to ensure a large number of cells are available for mass organ production. Similarly, medical imaging is needed to provide high resolution designs, which can be faithfully bioprinted. In the bioprinting stage, compatibility of biomaterials is needed to be matched with solidification kinetics to ensure constructs with high cell viability and fidelity are obtained. On the other hand, there is a need to develop bioprinters, which have high degrees of freedom of movement, perform without failure concerns for several hours and are compact, and affordable. Finally, maturation of bioprinted cells are governed by conditions provided during the post-bioprinting process. This review, for the first time, puts all the bioprinting stages in perspective of the whole process of bioprinting, and analyzes their current state-of-the art. It is concluded that bioprinting community will recognize the relative importance and optimize the parameter of each stage to obtain the desired outcomes.

Risk prediction for oral potentially malignant disorders using fuzzy analysis of cytomorphological and autofluorescence alterations in habitual smokers

AIM This study aims to develop a novel noninvasive method for early cancer trend diagnosis in habitual smokers by corroborating cytomorphological and autofluorescence alterations. MATERIALS & METHODS A total of 120 subjects were included and categorized into nonsmoker, smoker and clinically diagnosed oral potentially malignant disorder (OPMD) patients. Oral exfoliative epithelial cells were studied through differential interference contrast and fluorescence microscopy. Fuzzy trend analysis was performed using measured parameters for determining the risk factors among smokers. RESULTS The risk assessment in this study showed a positive correlation of smoking duration with early cancer risk factors with a correlation co-efficient of 0.86. CONCLUSION Alterations in cellular morphology and autofluorescence intensities showed positive correlation with OPMD. The present study will benefit to investigate early prediction of OPMD among susceptible individuals.

Autofluorescence signatures for classifying lung cells during epithelial mesenchymal transition

The cellular mechanism of epithelial mesenchymal transition (EMT) has been observed to play a pivotal role in embryogenesis, wound healing and cancer metastasis. This fundamentally dynamic phenomenon requires a multifaceted appreciation to evaluate its role in cancer progression. The present study documents alterations in the endogenous fluorescence signatures of lung cells (normal and cancer) to classify them during the progression of EMT and reports their association with cytomorphological and cytoskeletal attributes. Cellular endogenous red and green fluorescence showed a gradual increase during the progression of EMT while the blue component showed the reverse effect. Furthermore, randomness in F-actin fibrillar arrangement was notably elevated and its expression increased. Altered cell shape with heightened vimentin expression was also documented. Principal component analysis (PCA), an unsupervised classifier, was effectively employed endorsing these multi-level attributes to visualize EMT progression. Dimensionality reduction was further carried out to elucidate the significance of autofluorescence. Red fluorescence had the greatest contribution in differentiating cells during the transition. The features were re-evaluated using another in-house built binary classifier, namely vector valued regularized kernel approximation (VVRKFA), in order to understand EMT progression. Gradual increase in classification accuracy with EMT progression indicated cellular changes in the above-mentioned features. Logical corroboration of the findings suggested strong connections between cellular shape and cytoskeletal attributes with autofluorescence phenomena during EMT.

Repositing honey incorporated electrospun nanofiber membranes to provide anti-oxidant, anti-bacterial and anti-inflammatory microenvironment for wound regeneration

AbstractTopical application of honey for tissue regeneration, has recently regained attention in clinical practice with controlled studies affirming its efficacy and indicating its role in regeneration over repair. Parallely, to overcome difficulties of applying raw honey, several product development studies like nanofibrous matrices have been reported. However, one approach concentrated on achieving highest possible honey loading in the nanofiber membranes while other studies have found that only specific honey dilutions result in differential cellular responses on wound healing and re-epithelization. From these results, it can be suggested that high honey loading provides optimum external microenvironment, low-loaded membranes could provide a more conducive internal microenvironment for tissue regeneration. With this hypothesis, this paper sought to evaluate ability of low-honey loaded nanofibers to modulate the anti-oxidant, anti-biofilm and anti-inflammatory properties which are important to be maintained in wound micro-environment. A loading-dependent reduction of biofilm formation and anti-oxidant activity was noted in different concentration ranges investigated. After scratch assay, a certain honey loading (0.5%) afforded the maximum re-epithelization. Since there is lack of methods to determine anti-inflammatory properties of nanofiber membranes during epithelial healing process, we performed anti-inflammatory assessment of nano-fibers by evaluating the expressions of pro-inflammatory markers-Cycloxygenase-2 (COX-2) and Interleukin-6 (IL-6) and to confirm the optimized concentration. Considering the role of COX-2 and IL-6, the novel methodology used in this study can also be developed as an assay for anti-inflammatory matrices for wound healing.

Synthetic polymeric gel

Abstract Synthetic polymer gels possess unique combination of acceptable biocompatibility with tailorable mechanical and degradation properties. They can be synthesized by several methods with a wide compositional range. Their applications are thus witnessing rapid growth in drug delivery, regenerative medicine, microfluidics, bioprinting, stem cell delivery, etc. Scaffolds fabricated from such gels can mimic the natural microenvironment and provide variety of biophysical cues for cellular signaling. In this chapter, we provide a brief on properties of common synthetic gels such as poly(ethylene glycol), poly(vinyl alcohol), poly(methyl methacrylate), poly(hydroxyethylmethyl acrylate), polyurethanes, poly(amino acids), and poly(vinyl pyrrolidone). The important properties of several other synthetic polymer gels are also tabulated. The major application areas of the synthetic gels are also presented to the reader.

Classification of Sonoelastography Images of Prostate Cancer Using Transformation-Based Feature Extraction Techniques

Abstract Recent trends in medical imaging enable overcoming the limitations of noninvasive histological assessment and subjectivity concerns in diagnosis of several diseases. These advancements are complemented by computer-assisted diagnosis (CAD) algorithms to further enhance accuracy of diagnosis. CAD algorithms are able to monitor the prognosis of chronic diseases like cancer. Among different cancer types, prostate cancer is the most common cancer in men. Early diagnosis of this cancer is known to significantly enhance the survival rate of patients. In this chapter, a CAD algorithm has been presented for sonoelastography images, which is an ultrasound-based imaging technique that determines cancers through analyzing tissue elasticity. Fourier and wavelet-based transformations were used to classify the images after segmenting them into affected and unaffected regions based on the ground truth information obtained from clinician. Classification rate of a maximum of 97% was obtained using the stationary wavelet transform (SWT) method, whereas 94%, 96%, and 61% were obtained with fast Fourier transform (FFT), discrete wavelet transform (DWT), and spatial domain, respectively. The proposed study shows that sonoelastography images can be used for diagnosis of prostate cancer by applying wavelet technique.