Molecular-receptor-specific, non-toxic, near-infrared-emitting Au cluster-protein nanoconjugates for targeted cancer imaging

Molecular-receptor-targeted imaging of folate receptor positive oral carcinoma cells using folic-acid-conjugated fluorescent Au25 nanoclusters (Au NCs) is reported. Highly fluorescent Au25 clusters were synthesized by controlled reduction of Au+ ions, stabilized in bovine serum albumin (BSA), using a green-chemical reducing agent, ascorbic acid (vitamin-C). For targeted-imaging-based detection of cancer cells, the clusters were conjugated with folic acid (FA) through amide linkage with the BSA shell. The bioconjugated clusters show excellent stability over a wide range of pH from 4 to 14 and fluorescence efficiency of ~5.7% at pH 7.4 in phosphate buffer saline (PBS), indicating effective protection of nanoclusters by serum albumin during the bioconjugation reaction and cell-cluster interaction. The nanoclusters were characterized for their physico-chemical properties, toxicity and cancer targeting efficacy in vitro. X-ray photoelectron spectroscopy (XPS) suggests binding energies correlating to metal Au 4f7/2˜83.97 eV and Au 4f5/2~87.768 eV. Transmission electron microscopy and atomic force microscopy revealed the formation of individual nanoclusters of size ~1 nm and protein cluster aggregates of size ~8 nm. Photoluminescence studies show bright fluorescence with peak maximum at ~674 nm with the spectral profile covering the near-infrared (NIR) region, making it possible to image clusters at the 700-800 nm emission window where the tissue absorption of light is minimum. The cell viability and reactive oxygen toxicity studies indicate the non-toxic nature of the Au clusters up to relatively higher concentrations of 500 µg ml-1. Receptor-targeted cancer detection using Au clusters is demonstrated on FR+ve oral squamous cell carcinoma (KB) and breast adenocarcinoma cell MCF-7, where the FA-conjugated Au25 clusters were found internalized in significantly higher concentrations compared to the negative control cell lines. This study demonstrates the potential of using non-toxic fluorescent Au nanoclusters for the targeted imaging of cancer

On the selection and design of proteins and peptide derivatives for the production of photoluminescent, red-emitting gold quantum clusters

Novel pathways of the synthesis of photoluminescent gold quantum clusters (AuQCs) using biomolecules as reactants provide biocompatible products for biological imaging techniques. In order to rationalize the rules for the preparation of red-emitting AuQCs in aqueous phase using proteins or peptides, the role of different organic structural units was investigated. Three systems were studied: proteins, peptides, and amino acid mixtures, respectively. We have found that cysteine and tyrosine are indispensable residues. The SH/S-S ratio in a single molecule is not a critical factor in the synthesis, but on the other hand, the stoichiometry of cysteine residues and the gold precursor is crucial. These observations indicate the importance of proper chemical behavior of all species in a wide size range extending from the atomic distances (in the AuI-S semi ring) to nanometer distances covering the larger sizes of proteins assuring the hierarchical structure of the whole self-assembled system

Fluorescent Gold Nanoprobes for the Sensitive and Selective Detection for Hg2+

A simple, cost-effective yet rapid and sensitive sensor for on-site and real-time Hg2+ detection based on bovine serum albumin functionalized fluorescent gold nanoparticles as novel and environmentally friendly fluorescent probes was developed. Using this probe, aqueous Hg2+ can be detected at 0.1 nM in a facile way based on fluorescence quenching. This probe was also applied to determine the Hg2+ in the lake samples, and the results demonstrate low interference and high sensitivity

Christ siemens touraine syndrome: A rare case report

Christ-Siemens-Touraine (CST) is a rare hereditary disorder of X-linked recessive trait, characterized by abnormal development of two or more structures or tissues of ectodermal origin. The common clinical findings include hypodontia, hypohydrosis, hypotrichosis, and onychodysplasia. Although hypodontia is common, anodontia is a rare feature. Most of the patients are suffering from social rejection and consequent psychological trauma because of the facial dysmorphism and absence of multiple teeth. Oral rehabilitation is of prime importance for such patients. This article presents a case in a 5½-year-old boy presenting with altered manifestations affecting almost all the ectodermal structures like skin, hair, nails, teeth, sebaceous glands, sweat glands, salivary glands, mammary glands, and tear glands. He also had complete anodontia and dry mouth. A multidisciplinary treatment was given to the patient with the collaboration of various health professionals. The child gained confidence and was relieved from the psychological impact following the prosthetic rehabilitation

A clinicoradiographic comparison of the effects of platelet-rich fibrin gel and platelet-rich fibrin membrane as scaffolds in the apexification treatment of young permanent teeth

Aims: This triple blinded clinical trial was undertaken to check whether Platelet rich firin in its membrane form is as reliable as when it is in the gel form. Settings and Design: Triple blinded randomized clinical trial. Methods and Material: 20 patients in PRF gel group and 20 patients in PRF membrane group selected after randomization and considering inclusion and exclusion criteria were taken up for this study. The samples were clinically and radiographically evaluated for success. Results and Conclusions: Regenerative endodontics with PRF membrane is easier and less time consuming. They have similar clinical success.PRF gel gave a better radiographic success in 12 months period

Nasoalveolar molding treatment in presurgical infant orthopedics in cleft lip and cleft palate patients

The nasoalveolar molding (NAM) technique is a new approach to presurgical infant orthopedics that reduces the severity of the initial cleft alveolar and nasal deformity. This technique facilitates the primary surgical repair of the nose and lip to heal under minimal tension, thereby reducing scar formation and improving the esthetic result. NAM technique is the nonsurgical, passive method of bringing the gum and lip together by redirecting the forces of natural growth. NAM has proved to be an effective adjunctive therapy for reducing hard and soft tissue cleft deformity before surgery. This paper reviews the basic principles of NAM therapy, various types of appliances used in this therapy, protocol followed, and a critical evaluation of the advantages and disadvantages of this technique. Universally authors have agreed the positive outcome of NAM for better esthetics after cleft lip and palate (CLP) repair, but the long-term effects of this therapy are yet to be substantiated. Despite a relative paucity of high-level evidence, NAM appears to be a promising technique that deserves further research

Analysis of soil temperature in iso-hyperthermic temperature regime using Fourier technique

207-214A study has been conducted using soil climatic data of few stations in Kerala to verify the validity of the general statement regarding periodicity of soil temperature, that all tropical stations show bimodal pattern of soil temperature in the yearly cycle. For some stations the results were found to be true, but for Pilicode and Kottarakara a unimodal pattern was observed. At Kottarakara, it appears that unimodal pattern is due to irrigation used at that place. More data from other places which are influenced only by rain are needed to be examined and analysed to arrive at firm conclusion. However, from a preliminary analysis it is found that out of five stations studied, four show bimodal pattern. Variation of soil temperature with soil moisture also has been presented