Physicochemical Properties and Simulation of Magnesium/Zinc Binary-Substituted Hydroxyapatite with Enhanced Biocompatibility and Antibacterial Ability.

Ionic substitution can effectively activate the surface of hydroxyapatite (HA) for bone repair and regeneration processes. Therefore in this study, magnesium (Mg)-, zinc (Zn)-, and Mg/Zn-codoped HA was prepared by a hydrothermal method. The results of experimental and first-principles calculations verify the existence of Mg and Zn ions in the HA structure by altering cell parameters, crystallinity, and particle size. The results also showed that Mg and Zn are actively accommodated at the Ca(1) and Ca(2) positions, which not only inhibit HA formation but also promote calcium-deficient HA, and when the codoping content increased to 10%Mg and 10%Zn, the HA transformed completely to the whitlockite phase. Furthermore, the impact of codoping on biocompatibility was examined by employing MC3T3 cells. The in vitro study revealed that 5%Mg and 5%Zn single and -codoped HA promoted the proliferation of MC3T3 cells and 5%Mg-doped and -codoped HA stimulated MC3T3 cell differentiation, while 5%Zn-doped and -codoped HA revealed worthy antibacterial properties. Overall, the obtained results demonstrate that cosubstituted HA (5%Mg and 5%Zn) is promising, which not only eradicates bacteria (Escherichia coli and Staphylococcus aureus) but also induces bone regeneration. These findings suggest that 5%Mg and 5%Zn binary-substituted HA is a very promising biomaterial for hard tissue scaffolds and bone repair.

Novel Multidisciplinary Salivary Gland Society (MSGS) Questionnaire: An International Consensus.

OBJECTIVES: First, establishment and validation of a novel questionnaire documenting the burden of xerostomia and sialadenitis symptoms, including quality of life. Second, to compare two versions regarding the answering scale (proposed developed answers Q3 vs. 0-10 visual analogue scale Q10) of our newly developed questionnaire, in order to evaluate their comprehension by patients and their reproducibility in time. STUDY DESIGN: The study is a systematic review regarding the evaluation of the existing questionnaire and a cohort study regarding the validation of our new MSGS questionnaire. MATERIALS AND METHODS: A Multidisciplinary Salivary Gland Society (MSGS) questionnaire consisting of 20 questions and two scoring systems was developed to quantify symptoms of dry mouth and sialadenitis. Validation of the questionnaire was carried out on 199 patients with salivary pathologies (digestive, nasal, or age-related xerostomia, post radiation therapy, post radioiodine therapy, Sjögren's syndrome, IgG4 disease, recurrent juvenile parotitis, stones, and strictures) and a control group of 66 healthy volunteers. The coherence of the questionnaire's items, its reliability to distinguish patients from healthy volunteers, its comparison with unstimulated sialometry, and the time to fill both versions were assessed. RESULTS: The novel MSGS questionnaire showed good internal coherence of the items, indicating its pertinence: the scale reliability coefficients amounted to a Cronbach's alpha of 0.92 for Q10 and 0.90 for Q3. The time to complete Q3 and Q10 amounted, respectively, to 5.23 min (±2.3 min) and 5.65 min (±2.64 min) for patients and to 3.94 min (±3.94 min) and 3.75 min (±2.11 min) for healthy volunteers. The difference between Q3 and Q10 was not significant. CONCLUSION: We present a novel self-administered questionnaire quantifying xerostomia and non-tumoral salivary gland pathologies. We recommend the use of the Q10 version, as its scale type is well known in the literature and it translation for international use will be more accurate. Laryngoscope, 132:322-331, 2022.

Surgery for plunging ranula: the lesson not yet learned?

Our objective is to review our experience with treatment of plunging ranula and examine the efficacy of transoral excision of sublingual gland as the principal treatment. This study comprises a case series with chart review. A secondary otolaryngology service was used as the setting. Retrospective analysis of patient records was performed for a series of 95 consecutive cases of plunging ranula, which presented to our department between January 2001 and February 2010. Clinical presentation, investigations, diagnosis, treatment, complications and outcome were recorded. Literature search was performed using MEDLINE and OLD MEDLINE. 81 cases of plunging ranula were treated surgically by transoral excision of sublingual gland and evacuation of ranula contents. Mean operating time was 75.3 min. Twelve patients had undergone previous surgery elsewhere. One patient in our series had a recurrence, needing excision of sublingual gland remnant. Two patients had trauma to submandibular duct requiring excision of submandibular gland. Other complications were minor and transient. Review of literature revealed many diverse methods of treating ranula, with varying results. Our series makes a substantial contribution to the number of plunging ranulas reported in the world, and supports the use of transoral sublingual gland excision as first-line treatment of plunging ranula.

Bilateral Plunging Ranulas in South Auckland: Evidence for a Genetic Basis.

OBJECTIVES: We present a series of bilateral plunging ranula patients to examine the etiology, diagnosis, treatment, and prognosis of this condition. METHODS: A retrospective chart review was performed on all cases of plunging ranula treated at the Department of Otolaryngology-Head and Neck Surgery, Counties Manukau District Health Board, New Zealand, between 2001 and 2019. RESULTS: There were 17 patients with bilateral plunging ranulas from a total of 187 plunging ranula patients. Eight patients were of Pacific Island descent; six were Maori; and three were Asian. There were no European patients with bilateral plunging ranulas. There were three types of bilateral plunging ranula patients: 1) Metachronous plunging ranulas-Five patients presented with a unilateral plunging ranula with no evidence of a contralateral plunging ranula on initial imaging. Despite negative contralateral imaging findings, these patients developed a clinically evident contralateral plunging ranula 21 to 61 months later. 2) Synchronous plunging ranulas detected on imaging-Eight patients presented with a clinically evident unilateral plunging ranula but also had a contralateral plunging ranula detected on imaging. 3) Clinically evident synchronous plunging ranulas-Four patients presented with bilateral clinically evident plunging ranulas, which were also evident on imaging. Twelve patients underwent bilateral transoral sublingual gland excision and plunging ranula evacuation. CONCLUSION: All patients with a unilateral plunging ranula should be advised of the potential for developing contralateral disease, and this should be emphasized in patients of Pacific Island, Maori, and Asian descent. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:73-77, 2021.

Leaching behavior of Sb and Br from E-waste flame retardant plastics.

The improper disposal of E-waste flame retardant plastics laden with antimony (Sb) and bromine (Br) has brought enormous environmental hazards, however, rare information on the effective removal of Sb and Br is available. In this study, through building an alkaline sulfide system under hydrothermal conditions, Sb and Br were simultaneously extracted from flame retardant plastic with high efficiency of 85.60% and 90.13%, respectively. Sulfur ion through mass transfer reacted with encapsulated Sb2O3 to form safe and non-toxic SbS33-. Alkaline solution trapped the Br through substitution or neutralization reaction to inhibit the formation of brominated organic compounds. The results showed that the optimum temperature, residence time, Na2S and NaOH concentration for hydrothermal removal of Sb and Br were 220 °C, 2 h, 50 g/L and 20 g/L. The results also revealed that both Na2S and NaOH played an interrelated role in the process of Sb removal. However, NaOH was the only factor controlling the process of debromination. Moreover, the FTIR structure of plastic after alkaline sulfide hydrothermal treatment remained unchanged, which implies that the treated plastic can be reused, and is an added advantage of this technology. The TG-DTG analysis proved the effectiveness of alkaline sulfide hydrothermal treatment in removing Sb and Br.

Novel chemotherapy for tuberculosis: chemotherapeutic potential of econazole- and moxifloxacin-loaded PLG nanoparticles.

The potential of econazole (ECZ) and moxifloxacin (MOX) individually against tuberculosis (TB) caused by multidrug-resistant and latent Mycobacterium tuberculosis has been demonstrated. In this study, poly-(dl-lactide-co-glycolide) (PLG) nanoparticle-encapsulated ECZ and MOX were evaluated against murine TB (drug susceptible) in order to develop a more potent regimen for TB. PLG nanoparticles were prepared by the multiple emulsion and solvent evaporation technique and were administered orally to mice. A single oral dose of PLG nanoparticles resulted in therapeutic drug concentrations in plasma for up to 5 days (ECZ) or 4 days (MOX), whilst in the organs (lungs, liver and spleen) it was up to 6 days. In comparison, free drugs were cleared from the same organs within 12-24h. In M. tuberculosis-infected mice, eight oral doses of the formulation administered weekly were found to be equipotent to 56 doses (MOX administered daily) or 112 doses (ECZ administered twice daily) of free drugs. Furthermore, the combination of MOX+ECZ proved to be significantly efficacious compared with individual drugs. Addition of rifampicin (RIF) to this combination resulted in total bacterial clearance from the organs of mice in 8 weeks. PLG nanoparticles appear to have the potential for intermittent therapy of TB, and combination of MOX, ECZ and RIF is the most potent.

Sorption of lead ions onto oxidized bagasse-biochar mitigates Pb-induced oxidative stress on hydroponically grown chicory: Experimental observations and mechanisms.

This pilot study investigated the affinity of oxidized biochars to sorb lead ions (Pb2+) in aqueous solutions, and its potentiality to serve as bio-filters to detoxify Pb-induced oxidative stress on hydroponically grown chicory. Raw bagasse was slow-pyrolyzed at 600 °C to produce original biochar (O-B), which was further oxidized by HNO3 and KMnO4 to generate HNO3-B and KMnO4-B, respectively. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), digital selected-area electron diffraction (SAED) and Fourier transform infrared spectroscopy (FTIR) analyses were performed to study physicochemical properties of pre-and post-sorption samples. Kinetic and isothermal batch sorption experiments proved the high affinity of oxidized biochar to Pb2+ ions. Both physisorption and chemisorption mechanisms participated mutually in sorption process. Leaf histochemistry analysis showed various dysfunctions on plants grown under severe Pb-stress including (i) induction of oxidative stress, (ii) deactivation in antioxidant enzymatic and non-enzymatic defense pathways, (iii) defects in plant water status, (iv) disruption in photosynthetic pigments synthesis, and (v) disturbance in the membrane permeability to solute leakage. Biochar filters (particularly KMnO4-B) exhibited a scavenging effect against these adverse effects by reducing Pb-bioavailability. Furthermore, the chemical characteristics of biochar and its derivatives (biochar-derived humic acids) provided additional stimulating effect to plant scavenging mechanisms. This ameliorative effect of biochar filters minimized the dramatic reductions in vegetative measurements of plants grown under severe Pb-stress. Hence, this study provides insights regarding the potentiality to functionalize biochar and its derivatives for heavy metal detoxification.

Alginate nanoparticles as antituberculosis drug carriers: formulation development, pharmacokinetics and therapeutic potential.

BACKGROUND: Reduction in the dosing frequency of antituberculosis drugs (ATDs) by applying drug delivery technology has the potential to improve the patient compliance in tuberculosis (TB). Alginate (a natural polymer) based nanoparticulate delivery system was developed for frontline ATDs (rifampicin, isoniazid, pyrazinamide and ethambutol). METHODS: Alginate nanoparticles were prepared by the controlled cation induced gelification method and administered orally to mice. The drug levels were analysed by high performance liquid chromatography (HPLC) in plasma/tissues. The therapeutic efficacy was evaluated in M. tuberculosis H37Rv infected mice. RESULTS: High drug encapsulation efficiency was achieved in alginate nanoparticles, ranging from 70%-90%. A single oral dose resulted in therapeutic drug concentrations in the plasma for 7-11 days and in the organs (lungs, liver and spleen) for 15 days. In comparison to free drugs (which were cleared from plasma/organs within 12-24 h), there was a significant enhancement in the relative bioavailability of encapsulated drugs. In TB-infected mice three oral doses of the formulation spaced 15 days apart resulted in complete bacterial clearance from the organs, compared to 45 conventional doses of orally administered free drugs. CONCLUSIONS: Alginate nanoparticles appear to have the potential for intermittent therapy of TB.

Stabilizing poly(vinyl chloride) using its blends with poly(methyl methacarylate): pyrolysis GC/MS studies.

Binary blends of poly(vinyl chloride) (PVC) with poly(methyl methacarylate) (PMMA) of various compositions were prepared through solution blending. Thermogravimetric and pyrolysis studies of these blends were carried out and the volatile products were separated and quantitatively analyzed by GC/MS. Harmful pyrolysis products from PVC like HCl and different aromatic hydrocarbons are significantly suppressed in presence of a small amount of PMMA. The stabilization effect on PVC was found to be the most significant with 10 wt.%. PMMA contents in the matrix. Mechanism of the stabilization has been explained by the interaction of micro- and macro-radicals resulting from PMMA with PVC, which stabilize the unzipping of polymer chains by a reversible blocking mechanism and increase the amount of cross-linked residue retained above 500 °C.