Quantification of monodisperse and biocompatible gold nanoparticles by single-particle ICP-MS.

Bioanalytical and biomedical applications often require nanoparticles that exhibit narrow size distributions and biocompatibility. Here, we demonstrate how different synthesis methods affect gold nanoparticle (AuNPs) monodispersity and cytotoxicity. Using single particle inductively coupled plasma mass spectrometry (SP-ICP-MS), we found that the size distribution of AuNPs synthesized with a cetyltrimethylammonium chloride (CTAC) cap was significantly improved compared to AuNPs synthesized with citrate capping agents. We determined an up to 4× decrease in the full width at half maximum (FWHM) value of the normal distributions of AuNP diameter and up to a 12% decrease in relative standard deviation (RSD). While the CTAC-capped AuNPs exhibit narrow nanoparticle size distributions, they are cytotoxic, which limits safe and effective bioanalytical and biomedical applications. We sought to impart biocompatibility to CTAC-capped AuNPs through a PEGylation-based surface ligand exchange. We developed a unique ligand exchange method driven by physical force. We demonstrated the successful PEGylation using various PEG derivatives and used these PEGylated nanoparticles to further bioconjugate nucleic acids and peptides. Using cell viability quantification, we confirmed that the monodisperse PEGylated AuNPs were biocompatible. Our monodisperse and biocompatible nanoparticles may advance safe and effective bioanalytical and biomedical applications of nanomaterials.

Nanoparticle Surface Engineering with Heparosan Polysaccharide Reduces Serum Protein Adsorption and Enhances Cellular Uptake.

Nanoparticle modification with poly(ethylene glycol) (PEG) is a widely used surface engineering strategy in nanomedicine. However, since the artificial PEG polymer may adversely impact nanomedicine safety and efficacy, alternative surface modifications are needed. Here, we explored the "self" polysaccharide heparosan (HEP) to prepare colloidally stable HEP-coated nanoparticles, including gold and silver nanoparticles and liposomes. We found that the HEP-coating reduced the nanoparticle protein corona formation as efficiently as PEG coatings upon serum incubation. Liquid chromatography-mass spectrometry revealed the protein corona profiles. Heparosan-coated nanoparticles exhibited up to 230-fold higher uptake in certain innate immune cells, but not in other tested cell types, than PEGylated nanoparticles. No noticeable cytotoxicity was observed. Serum proteins did not mediate the high cell uptake of HEP-coated nanoparticles. Our work suggests that HEP polymers may be an effective surface modification technology for nanomedicines to safely and efficiently target certain innate immune cells.

A Digital Radiographic Study of Age Estimation Using Area-specific Formula in Odisha Population.

AIM: The aim of the article was to evaluate the feasibility of pulp/tooth area ratio in three mandibular teeth, namely left canine, left first premolar, and left second premolar (33, 34, and 35), as an indicator of age using digital panoramic radiograph and Kvaal's parameters. The study also aimed at computing an area-specific formula for age estimation in Odisha population. MATERIALS AND METHODS: Observation and analysis of 50 digital orthopantomographs (OPGs) and clinical data of patients were made. These images were saved as high-resolution JPEG files. Using the Adobe Photoshop CS3 (extended) image editing software program (Adobe Systems Inc, San Jose, California, United States), the pulp/tooth area ratio of 33, 34, and 35 was analyzed. These ratios were substituted in Odisha population-specific formula, derived using principal component regression analysis. RESULTS: The mean chronological age was 33.24 years. Principal component regression analysis was used to derive multiple regression formulae for individual teeth as well as a combined formula. R2 (coefficient of determination) for combined three mandibular teeth was highest (0.7769) with a standard error of 4.5969 years and thus was a better predictor of age in the population of Odisha. In terms of an individual tooth, comparison between chronological and predicted age revealed that left second mandibular premolar (35) had highest correlation to actual age. Karl Pearson's correlation coefficient showed correlation between age and the mean of ratios from combined three mandibular teeth was stronger than that of single tooth. CONCLUSION: In the present study, second left mandibular premolar showed highest correlation to actual age when used alone. The use of three teeth in combination increased the correlation. This Odisha-specific formula showed promising results and can be used for forensic applications in this population. CLINICAL SIGNIFICANCE: Using three different teeth for age estimation proved to be a better predictor of age in the Odisha population. Moreover, the obtained formula can act as a standard and be used for anthropological or forensic investigations in the said population.

Assessment of lactate dehydrogenase enzyme levels in saliva and serum of oral submucous fibrosis and leukoplakia patients.

BACKGROUND: Pathology involving the oral epithelium may alter the level of salivary concentration of LDH. Thus its estimation can be used as a non invasive screening tool for the early detection of OPMDs and also to predict its malignant transformation especially in high risk population. AIMS AND OBJECTIVES: To evaluate the salivary and serum levels of lactate dehydrogenase (LDH) in patients having of oral submucous fibrosis (OSMF) and leukoplakia and compare it with healthy individuals. MATERIALS AND METHODS: A total of 120 subjects were selected and divided into three groups comprising clinically diagnosed cases of OSMF and leukoplakia and healthy subjects as controls. Unstimulated whole saliva and blood samples were collected under aseptic conditions for biochemical estimation of LDH by Semiautomatic Analyzer using LDH kit utilizing enzymatic UV-Kinetic method. The values obtained were statistically analyzed using the SPSS software version 20.0. P-value < 0.05 was considered significant. RESULTS: The mean salivary LDH level in Group I (OSMF) was 631.67 + 7.67, Group II (Leukoplakia) was 492.28 + 16.17 and Group III (Healthy Control) was 140.62 + 8.87. There was a statistically significant difference between the Serum and salivary LDH levels among the various groups of study population. A positive correlation between salivary LDH and serum LDH level was seen and the regression equation for OSMF and leukoplakia was computed. CONCLUSION: A significant difference was found between mean salivary LDH Levels and serum LDH levels in patients with leukoplakia, OSMF and health controls. A positive correlation was also established between salivary and serum LDH levels in patients with OSMF and leukoplakia patients making saliva a potent non invasive tool for early prediction and detection of PMOD and its malignant transformation.

Assessment of knowledge of oral pathologists and postgraduate students on safe laboratory practices during the COVID-19 pandemic.

BACKGROUND: Oral pathologists are involved in laboratory diagnosis and receive specimens of biopsy, oral cytologic smears and samples for hematology, biochemistry and microbiology and thus are at a risk for laboratory-acquired infections, which may occur inadvertently and can be considered as an occupational hazard. AIM AND OBJECTIVES: This study was conducted during the coronavirus disease (COVID-19) pandemic to assess the knowledge of oral pathologists and oral pathology postgraduate students regarding the safe laboratory practices, procedures and guidelines. MATERIALS AND METHODS: The study was a cross-sectional online questionnaire-based study. Questions were framed to evaluate the knowledge on specimen/sample collection, its handling, disposal and protective measures for laboratory personnel. The study population comprised oral pathologists and oral pathology postgraduate students of various dental colleges in India. A Google Doc format was used to create an effective computerized questionnaire system, and the link was forwarded to around 500 participants. The survey was fielded online between August 29, 2020, and September 5, 2020. Three hundred and twelve responses were received, which were downloaded as spreadsheets for subsequent data analysis. RESULTS: Mean value of right answers for the oral pathologists was 8.11 ± 2.02 and for postgraduate students was 7.38 ± 1.75. When the knowledge score between the two groups was compared, a statistically significant difference was found. CONCLUSION: This article compares and highlights the knowledge lacunae among the oral pathologists and oral pathologists postgraduate students in relation to guidelines to be followed for safety in the laboratory. Adhering to these biosafety regulations reduces occupational health hazards and enhances a safe working environment in the laboratory.