Prevalence and attributes of traumatic dental injuries to anterior teeth among school going children of Kolkata, India.

Background: Traumatic Dental Injuries (TDI) have emerged as a very significant public health and social problem, especially among children and adolescents. The aim of this study was to investigate the prevalence and associated risk factors of traumatic dental injuries to permanent anterior teeth in school going children of Kolkata aged 7-14 years. Method: A cross-sectional study was conducted among 3762 school going children attending various private and public schools of Kolkata aged 7-14 years. A multistage random clustering sampling technique was adopted to select the children.Type of trauma using Ellis and Davey classification of fractures along with Andresen's Epidemiological Classification of Traumatic Injuries to Anterior Teeth, including WHO codes, was used. All values were considered statistically significant at P < 0.05. Results: Prevalence of TDI to anterior teeth was found to be 9.89%. The mean age of children who presented with TDI was 11.06 ± 1.99.years. The most common place of occurrence of TDI was home. Falls were the most common causes of trauma. Children belonging to higher socioeconomic status were observed to have an increased prevalence of TDIs.The highest potential risk factor for the occurrence of trauma was a past history of trauma. Conclusion: Present study found a prevalence of 9.89%, and a very low percentage of children had received treatment.

Cucurbit[7]uril Macrocyclic Sensors for Optical Fingerprinting: Predicting Protein Structural Changes to Identifying Disease-Specific Amyloid Assemblies.

In a three-dimensional (3D) representation, each protein molecule displays a specific pattern of chemical and topological features, which are altered during its misfolding and aggregation pathway. Generating a recognizable fingerprint from such features could provide an enticing approach not only to identify these biomolecules but also to gain clues regarding their folding state and the occurrence of pathologically lethal misfolded aggregates. We report here a universal strategy to generate a fluorescent fingerprint from biomolecules by employing the pan-selective molecular recognition feature of a cucurbit[7]uril (CB[7]) macrocyclic receptor. We implemented a direct sensing strategy by covalently tethering CB[7] with a library of fluorescent reporters. When CB[7] recognizes the chemical and geometrical features of a biomolecule, it brings the tethered fluorophore into the vicinity, concomitantly reporting the nature of its binding microenvironment through a change in their optical signature. The photophysical properties of the fluorophores allow a multitude of probing modes, while their structural features provide additional binding diversity, generating a distinct fluorescence fingerprint from the biomolecule. We first used this strategy to rapidly discriminate a diverse range of protein analytes. The macrocyclic sensor was then applied to probe conformational changes in the protein structure and identify the formation of oligomeric and fibrillar species from misfolded proteins. Notably, the sensor system allowed us to differentiate between different self-assembled forms of the disease-specific amyloid-ß (Aß) aggregates and segregated them from other generic amyloid structures with a 100% identification accuracy. Ultimately, this sensor system predicted clinically relevant changes by fingerprinting serum samples from a cohort of pregnant women.

Interfacial tetrazine click chemistry mediated assembly of multifunctional colloidosomes.

We demonstrate that tetrazine ligation chemistry can be employed to cross-link and assemble gold nanoparticles at the water-oil interface to create plasmonic colloidosomes. These biocompatible colloidosomes exhibit size tunability via controllable ligation kinetics and display high encapsulation efficiency, size-selective permeability, and surface-enhanced Raman scattering (SERS)-based sensing modality.

Multiplexed optical barcoding of cells via photochemical programming of bioorthogonal host-guest recognition.

Modern chemical and biological studies are undergoing a paradigm shift, where understanding the fate of individual cells, in an apparently homogeneous population, is becoming increasingly important. This has inculcated a growing demand for developing strategies that label individual cells with unique fluorescent signatures or barcodes so that their spatiotemporal trajectories can be mapped in real time. Among various approaches, light-regulated methods employing photocaged fluorophores have received particular attention, owing to their fine spatiotemporal control over labelling. However, their multiplexed use to barcode large numbers of cells for interrogating cellular libraries or complex tissues remains inherently challenging, due to the lack of multiple spectrally distinct photoactivated states in the currently available photocaged fluorophores. We report here an alternative multiplexable strategy based on optically controlled host-guest recognition in the cucurbit[7]uril (CB[7]) system that provides spatial control over the positioning of fluorophores to generate distinct barcodes in 'user-defined' cells. Using a combination of three spectrally distinct CB[7]-conjugated fluorophores and by sequentially performing cycles of photoactivation and fluorophore encoding, we demonstrate 10-color barcoding in microtubule-targeted fixed cells as well as 7-color barcoding in cell surface glycan targeted live MCF7 cells.

Dynamic host-guest interaction enables autonomous single molecule blinking and super-resolution imaging.

Synthetic host-guest complexes are inherently dynamic as they employ weak and reversible noncovalent interactions for their recognition processes. We strategically exploited dynamic supramolecular recognition between fluorescently labeled guest molecules to complementary cucurbit[7]uril hosts to obtain stochastic switching between fluorescence ON- and OFF-states, enabling PAINT-based nanoscopic imaging in cells and tissues.

Multichannel DNA Sensor Array Fingerprints Cell States and Identifies Pharmacological Effectors of Catabolic Processes.

Cells at disease onset are often associated with subtle changes in the expression level of a single or few molecular components, making traditionally used biomarker-driven clinical diagnosis a challenging task. We demonstrate here the design of a DNA nanosensor array with multichannel output that identifies the normal or pathological state of a cell based on the alteration of its global proteomic signature. Fluorophore-encoded single-stranded DNA (ssDNA) strands were coupled via supramolecular interaction with a surface-functionalized gold nanoparticle quencher to generate this integrated sensor array. In this design, ssDNA sequences exhibit dual roles, where they provide differential affinities with the receptor gold nanoparticle as well as act as transducer elements. The unique interaction mode of the analyte molecules disrupts the noncovalent supramolecular complexation, generating simultaneous multichannel fluorescence output to enable signature-based analyte identification via a linear discriminant analysis-based machine learning algorithm. Different cell types, particularly normal and cancerous cells, were effectively distinguished using their fluorescent fingerprints. Additionally, this DNA sensor array displayed excellent sensitivity to identify cellular alterations associated with chemical modulation of catabolic processes. Importantly, pharmacological effectors, which could modulate autophagic flux, have been effectively distinguished by generating responses from their global protein signatures. Taken together, these studies demonstrate that our multichannel DNA nanosensor is well suited for rapid identification of subtle changes in a complex mixture and thus can be readily expanded for point-of-care clinical diagnosis, high-throughput drug screening, or predicting the therapeutic outcome from a limited sample volume.

Solvent Adaptive Dynamic Metal-Organic Soft Hybrid for Imaging and Biological Delivery.

A solvent responsive dynamic nanoscale metal-organic framework (NMOF) [Zn(1 a)(H2 O)2 ] has been devised based on the self-assembly of ZnII and asymmetric bola-amphiphilic oligo-(p-phenyleneethynylene) (OPE) dicarboxylate linker 1 a having dodecyl and triethyleneglycolmonomethylether (TEG, polar) side chains. In THF solvent, NMOF showed nanovesicular morphology (NMOF-1) with surface decorated dodecyl chains. In water and methanol, NMOF exhibited inverse-nanovesicle (NMOF-2) and nanoscroll (NMOF-3) morphology, respectively, with surface projected TEG chains. The pre-formed NMOFs also unveiled reversible solvent responsive transformation of different morphologies. The flexible NMOF showed cyan emission and no cytotoxicity, allowing live cell imaging. Cisplatin (14.4 wt %) and doxorubicin (4.1 wt %) were encapsulated in NMOF-1 by non-covalent interactions and, in vitro and in vivo drug release was studied. The drug loaded NMOFs exhibited micromolar cytotoxicity.

Synthetic Host-Guest Assembly in Cells and Tissues: Fast, Stable, and Selective Bioorthogonal Imaging via Molecular Recognition.

Bioorthogonal strategies are continuing to pave the way for new analytical tools in biology. Although a significant amount of progress has been made in developing covalent reaction based bioorthogonal strategies, balanced reactivity, and stability are often difficult to achieve from these systems. Alternatively, despite being kinetically beneficial, the development of noncovalent approaches that utilize fully synthetic and stable components remains challenging due to the lack of selectivity in conventional noncovalent interactions in the living cellular environment. Herein, we introduce a bioorthogonal assembly strategy based on a synthetic host-guest system featuring Cucurbit[7]uril (CB[7]) and adamantylamine (ADA). We demonstrate that highly selective and ultrastable host-guest interaction between CB[7] and ADA provides a noncovalent mechanism for assembling labeling agents, such as fluorophores and DNA, in cells and tissues for bioorthogonal imaging of molecular targets. Additionally, by combining with covalent reaction, we show that this CB[7]-ADA based noncovalent interaction enables simultaneous bioorthogonal labeling and multiplexed imaging in cells as well as tissue sections. Finally, we show that interaction between CB[7] and ADA fulfills the demands of specificity and stability that is required for assembling molecules in the complexities of a living cell. We demonstrate this by sensitive detection of metastatic cancer-associated cell surface protein marker as well as by showing the distribution and dynamics of F-actin in living cells.

Cucurbit[7]uril-Directed Assembly of Colloidal Membrane and Stimuli-Responsive Microcapsules at the liquid-liquid Interface.

Colloidal microcapsules based on supramolecular architectures feature attractive properties and offer new opportunities in diverse areas such as delivery, sensing, and catalysis. Herein, we report a new strategy to fabricate the colloidal membrane and stimuli-responsive microcapsules by utilizing cucurbit[7]uril-mediated interfacial host-guest molecular recognition. In contrast to the traditionally used cross-linking approach, this method exploits the engineered interaction between a nanoparticle ligand and cucurbit[7]uril to tune the interfacial energy and stabilize the colloidal assembly at the interface. These capsules provide a versatile platform for simultaneous encapsulation of dual cargos. Additionally, the dynamic nature of the supramolecular interactions allows triggered release of the encapsulated cargos through the orthogonal presentation of a high affinity guest molecule.

Reversible encapsulations and stimuli-responsive biological delivery from a dynamically assembled cucurbit[7]uril host and nanoparticle guest scaffold.

The positive outcome of any therapeutic molecule requires control over its delivery rate. When delivered without control, administration of large doses is required to stimulate a therapeutic effect, frequently leading to increased toxicity or undesirable side effects. Recent advances introduced "smart" materials that actively release drugs in response to environmental stimuli. Although a variety of endogenous and exogenous triggers are reported, they are either difficult to control or lack tissue penetration depth. We report here a dynamic drug delivery scaffold based on a cucurbit[7]uril (CB[7]) host and benzylammonium functionalized gold nanoparticle (AuNP) guest that utilizes a bioorthogonal small molecule to achieve therapeutic control. In addition to their ability to reach deep tissue, small molecule activation is benefitted by their external controllability. Through cell culture studies we demonstrate that the host-guest supramolecular scaffold provides a nontoxic platform that effectively encapsulates a variety of therapeutic molecules and controls the payload release upon exposure to a high-affinity competitive guest molecule. This study presents a new strategy for controlling drug release rate through the use of competitive interactions of orthogonally presented guest molecules with immediate advantages in dosage control.

Evaluation of knowledge, awareness, and attitude toward emergency dental trauma management among the school teachers of Kolkata.

INTRODUCTION: Traumatic dental injuries (TDIs) are very common in childhood. Majority of TDI occur at home followed by schools. The prognosis of TDIs to a great extent is dependent on prompt emergency measures taken at the site of accident. Hence, it is of paramount importance to assess the knowledge of people present at the site of accident that generally includes parents, teachers, and sports coaches. AIM OF STUDY: The aim of the study was to assess the knowledge, attitude, and awareness of school teachers of Kolkata regarding management of TDIs. MATERIALS AND METHODS: A cross-sectional survey was conducted on 400 school teachers of Kolkata over a period of 2 months using a pretested close-ended questionnaire. The questionnaire had three parts: Part 1 contained questions on personal information, Part 2 contained questions based on two imaginary cases of trauma, and Part 3 related to their attitude toward dental trauma education. Chi-square test was done to describe the strength of the associations. RESULTS: The overall knowledge of school teachers regarding management of TDIs was not found to be satisfactory. It was observed that most of the teachers were in favor of taking immediate professional consultation for the emergency management, but most of them were unaware of the steps to be taken on their part to minimize complications and improve prognosis. CONCLUSION: Despite the lack of knowledge and awareness regarding management of dental trauma, school teachers of Kolkata had a good attitude toward management of dental trauma and its education.

let-7 miRNA controls CED-7 homotypic adhesion and EFF-1-mediated axonal self-fusion to restore touch sensation following injury.

Neuronal injury often leads to devastating consequences such as loss of senses or locomotion. Restoration of function after injury relies on whether the injured axons can find their target cells. Although fusion between injured proximal axon and distal fragment has been observed in many organisms, its functional significance is not clear. Here, using Caenorhabditis elegans mechanosensory neurons, we address this question. Using two femtosecond lasers simultaneously, we could scan and sever posterior lateral microtubule neurons [posterior lateral microtubules (PLMs)] on both sides of the worm. We showed that axotomy of both PLMs leads to a dramatic loss of posterior touch sensation. During the regenerative phase, only axons that fuse to their distal counterparts contribute to functional recovery. Loss of let-7 miRNA promotes functional restoration in both larval and adult stages. In the L4 stage, loss of let-7 increases fusion events by increasing the mRNA level of one of the cell-recognition molecules, CED-7. The ability to establish cytoplasmic continuity between the proximal and distal ends declines with age. Loss of let-7 overcomes this barrier by promoting axonal transport and enrichment of the EFF-1 fusogen at the growing tip of cut processes. Our data reveal the functional property of a regenerating neuron.

Knowledge, Awareness and Attitude towards Emergency Management of Dental Trauma among the Parents of Kolkata-An Institutional Study.

INTRODUCTION: Traumatic dental injuries are one of the commonly encountered dental emergencies. Missing anterior tooth in children due to any injury can be a source of considerable physical and psychological discomfort for the child. The prognosis of some dental injuries depends to a great extent on parents' knowledge of correct and prompt emergency measures. AIM: The purpose of this cross-sectional study was to assess the knowledge, attitude and awareness level of parents regarding the emergency management of dental trauma and to find out the relation of the responses to social variables. MATERIALS AND METHODS: A total of 2000 parents were surveyed over a period of three months using a pretested close ended questionnaire prepared in English, Hindi as well as in the regional language which was divided into three parts: Part 1 contained questions on personal information, Part 2 on an imaginary case of trauma to assess their knowledge regarding trauma management and Part 3 related to their attitude towards dental trauma management education. The data was statistically analysed using descriptive and chi-square statistics. RESULTS: The overall knowledge of parents regarding emergency management of trauma was not satisfactory. Although most of the people were in favour of taking professional consultation for emergency management of trauma but most of them were unaware of the steps that need to be taken on their part so as to minimize complications and improve prognosis. CONCLUSION: Educational campaigns are the need of the day to increase the knowledge of parents regarding emergency management of dental trauma.

Maxillary palatal ramp prosthesis: A prosthodontic solution to manage mandibular deviation following surgery.

Mandibular resection following surgical treatment for neoplastic lesions of the oral cavity leads to numerous complications including altered mandibular movements, disfigurement, difficult in swallowing, impaired speech and articulation, and deviation of the mandible towards the resected site. Various prosthetic methods are employed to reduce or minimize mandibular deviation and improve and restore the lost functions and esthetic, like maxillomandibular fixation, implant supported prosthesis, removable mandibular guide flange prosthesis, and palatal based guidance restoration. This clinical report describes the rehabilitation of a patient following segmental mandibulectomy using palatal ramp prosthesis.