MALDI(+) FT-ICR Mass Spectrometry (MS) Combined with Machine Learning toward Saliva-Based Diagnostic Screening for COVID-19.

Rapid identification of existing respiratory viruses in biological samples is of utmost importance in strategies to combat pandemics. Inputting MALDI FT-ICR MS (matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry) data output into machine learning algorithms could hold promise in classifying positive samples for SARS-CoV-2. This study aimed to develop a fast and effective methodology to perform saliva-based screening of patients with suspected COVID-19, using the MALDI FT-ICR MS technique with a support vector machine (SVM). In the method optimization, the best sample preparation was obtained with the digestion of saliva in 10 µL of trypsin for 2 h and the MALDI analysis, which presented a satisfactory resolution for the analysis with 1 M. SVM models were created with data from the analysis of 97 samples that were designated as SARS-CoV-2 positives versus 52 negatives, confirmed by RT-PCR tests. SVM1 and SVM2 models showed the best results. The calibration group obtained 100% accuracy, and the test group 95.6% (SVM1) and 86.7% (SVM2). SVM1 selected 780 variables and has a false negative rate (FNR) of 0%, while SVM2 selected only two variables with a FNR of 3%. The proposed methodology suggests a promising tool to aid screening for COVID-19.

Root coverage with tunneling technique or modified advanced flap associated with acellular dermal matrix: results from 6 months randomized clinical trial.

OBJECTIVES: This study compared two surgical techniques using acellular dermal matrix (ADM) for the treatment of multiple gingival recessions. MATERIAL AND METHODS: Twenty patients, with bilateral RT1 gingival recessions, were selected. One side received a modified extended coronally advanced flap (MECAF), and the contralateral side a supra-periosteal flap (TUN). The evaluated parameters were probing depth (PD), relative clinical attachment level, gingival index, gingival recession height (GR), width of keratinized tissue, keratinized tissue thickness, and gingival recession area at baseline and 6 months postoperative. Pain was evaluated weekly, using a visual analog scale (VAS) during first month postoperative. RESULTS: Both groups were effective in reducing GR (ΔGR: MECAF 2.28 mm; TUN 1.93 mm), without significant differences. The % of root coverage was numerically superior favoring MECAF (MECAF 61.24%; TUN 56.07%), without significant differences between groups. VAS scale failed to provide differences between groups. CONCLUSIONS: Both treatment were effective in root coverage and might be valuable for the treatment of multiple gingival recessions. The use of vertical releasing incisions and a flap design including the papillae did not hamper root coverage. CLINICAL RELEVANCE: This study compared two techniques for use of ADM in large multiple gingival recessions. Within its limitations, both treatments successfully achieved root coverage and were able to reduce gingival recession. It is expected a partial root coverage when using these techniques in large gingival recessions. The study failed to provide significant differences between groups. The use of modified extended coronally advanced flap may be advisable for the treatment of multiple gingival recessions, specially involving large defects when using ADM, to avoid early matrix exposure.

Aptamers recognizing fibronectin confer improved bioactivity to biomaterials and promote new bone formation in a periodontal defect in rats.

The use of alloplastic materials in periodontal regenerative therapies is limited by their incapacity to establish a dynamic dialog with the surrounding milieu. The aim of the present study was to control biomaterial surface bioactivity by introducing aptamers to induce the selective adsorption of fibronectin from blood, thus promoting platelets activation in vitro and bone regeneration in vivo. A hyaluronic acid/polyethyleneglycole-based hydrogel was enriched with aptamers selected for recognizing and binding fibronectin. In vitro, the capacity of constructs to support osteoblast adhesion, as well as platelets aggregation and activation was assessed by chemiluminescence within 24 h. Matrices were then evaluated in a rat periodontal defect to assess their regenerative potential by microcomputed tomography (µCT) and their osteogenic capacity by Luminex assay 5, 15 and 30 d postoperatively. Aptamers were found to confer matrices the capacity of sustaining firm cell adhesion (p = 0.0377) and to promote platelets activation (p = 0.0442). In vivo, aptamers promoted new bone formation 30 d post-operatively (p < 0.001) by enhancing osteoblastic lineage commitment maturation. Aptamers are a viable surface modification, which confers alloplastic materials the potential capacity to orchestrate blood clot formation, thus controlling bone healing.