Influence of radiotherapy on dental implants placed in individuals before diagnosed with head and neck cancer: focus on implant-bed-specific radiation dosage.

OBJECTIVES: The influence of radiotherapy on implants placed before diagnosed as head and neck cancer (HNC) is a potentially informative but poorly explored topic. The aims of this study were to investigate the influence of implant-bed-specific radiation dose on dental implants and to evaluate the impact of these implants on radiation dosimetry. MATERIAL AND METHODS: We conducted a retrospective study with 58 irradiated patients that received dental implant restorations before undergoing radiation treatment for HNC. The radiological success rate and the peri-implant bone resorption values were measured radiographically at 1 and 3 years after radiotherapy. Patients with no implants matching tumor site and stage served as a control group (n = 58). RESULTS: The median implant-bed-specific radiation dose was 40.3 Gy, which was significantly lower than tumor bed 62.4 Gy. An implant-bed-specific radiation dose higher than 40.0 Gy showed a significantly decreased radiologic success rate when compared to lower doses. Finally, evaluation of the radiation treatment plans revealed similar radiation hot spots in the test group of patients with implants and those of the control group. CONCLUSION: Our study confirms that radiotherapy negatively worsens peri-implant bone resorption, especially for implant-bed-specific dose more than 40 Gy, and the presence of implants within the radiation fields does not alter radiation dosimetry. The findings could be clinically informative to both surgeons and radio-oncologists. CLINICAL RELEVANCE: The interactions between radiotherapy and implants placed prior to radiotherapy treatment remain a largely unexplored topic. Based on the analysis of 3-dimensional modulated radiation plans, this study demonstrates the impact of implant-bed-specific radiation dose on marginal bone resorption of implants placed pre-radiation and considers the influence of these implants on radiation dosimetry. REGISTRATION NUMBER: CHICTR2100051923: ( http://www.chictr.org.cn/usercenter.aspx ).

Investigation on the in vitro cytocompatibility of Mg-Zn-Y-Nd-Zr alloys as degradable orthopaedic implant materials.

Mg-Zn-Y-Nd-Zr alloy has been developed as a new type of biodegradable orthopaedic implant material by the authors' research group with its excellent mechanical properties and controllable degradation rate. In this study, the cytocompatibility of Mg-Zn-Y-Nd-Zr alloy was systematically evaluated through in vitro cell culture method. MTT assay was applied to evaluate the cytotoxicity of Mg-Zn-Y-Nd-Zr alloy and no toxic effect was observed on L929 and MC3T3-E1 cells followed the protocol of ISO 10993 standard. Considering the potential ion accumulation in the bony environment, this study further investigated the cytotoxic effect of accumulated metallic ions during the alloy degradation by extending the extract preparation time. When the extract preparation time was prolonged to 1440 h, the accumulated metallic ions leaded to severe cell apoptosis, of which the combined ion concentration was determined as 39.5-65.8 µM of Mg2+, 3.5-5.9 µM of Zn2+, 0.44-0.74 µM of Y3+, 0.3-0.52 µM of Nd3+ and 0.11-0.18 µM of Zr4+ for L929, and 65.8-92.2 µM of Mg2+, 5.9-8.3 µM of Zn2+, 0.74-1.04 µM of Y3+, 0.52-0.73 µM of Nd3+ and 0.18-0.25 µM of Zr4+ for MC3T3-E1 cells. Besides the cell viability assessment, high expression of ALP activity and calcified nodules implied that metal elements in Mg-Zn-Y-Nd-Zr alloys can promote the osteogenic differentiation. Hence, excellent cytocompatibility has equipped Mg-Zn-Y-Nd-Zr alloy as a promising candidate for orthopaedic implant application, which can remarkably guide the magnesium-based alloy design and provide scientific evidence for clinical practice in future.

Regulation of the colon-targeted release rate of lactoferrin by constructing hydrophobic ethyl cellulose/pectin composite nanofibrous carrier and its effect on anti-colon cancer activity.

In order to modify colonic release behavior of lactoferrin (Lf), a hydrophobic composite nanofibrous carrier (CNC) was constructed by emulsion coaxial electrospinning. Ethylcellulose/pectin based water-in-oil emulsion and Lf-contained polyvinyl alcohol solution were used as shell and core fluids, respectively. An electrospinning diagram was first constructed to screen out suitable viscosity (51-82 cP) and conductivity (960-1300 µS/cm) of the dispersed phase of pectin solution for successful electrospinning of shell emulsion. Varying mass fraction of pectin solution (5 %-20 %) of shell emulsion during emulsion coaxial electrospinning obtained CNCs with different micro-structures, labeled as 5&95 CNC, 10&90 CNC, 15&85 CNC, 20&80 CNC. These CNCs all achieved colonic delivery of Lf (>95 %), and the time for complete release of Lf in simulated colon fermentation process were 10, 7, 5 and 3 h, respectively. That is, the greater the pectin content in CNC, the faster the release rate of stabilized Lf in colon. Lf release in simulated colon fermentation fluid involved complex mechanisms, in which diffusion release of Lf was dominant. Increasing colonic release rate of Lf enhanced its regulation effect on the expression levels of cell cycle arrest and apoptosis-related protein and promote its effective inhibition on the proliferation of HCT116 cell.

The efficacy of three-ball breathing apparatus exercise based on the concept of pulmonary rehabilitation in patients after lung cancer surgery.

BACKGROUND: Postoperative patients with lung cancer mostly experience different degrees of dyspnea and decreased activity tolerance, and these symptoms all significantly affect postoperative quality of life. The concept of pulmonary rehabilitation applicable to patients with chronic respiratory diseases is also applicable to patients with postoperative lung cancer. The current application of postoperative pulmonary rehabilitation for lung cancer is inconsistent, and reliable guidelines are lacking. The purpose of this study was to further verify the efficacy and feasibility of postoperative pulmonary rehabilitation for lung cancer patients, and to find a suitable local pulmonary rehabilitation program for postoperative patients with lung cancer that is clinically promoted in our department through this study. METHODS: We collected the clinical data of patients undergoing video-assisted thoracoscopic surgery (VATS) wedge resection or lobectomy. The patients were divided into rehabilitation group (using three-ball breathing apparatus after discharge) and control group (routine follow-up after discharge) according to whether the patients were trained with three-ball breathing apparatus after operation. The detailed method using three-ball apparatus is as follows. To begin with, patients are required to put themselves in a comfortable position. Then, after the three-ball breathing apparatus put on the same plane of their eyes, patients hold the tube in their mouth closely and control their breath slowly. When patients inhale to their largest extent, the balls will rise up accordingly. Then they exhale. The evaluation results of pulmonary function, activity tolerance, anxiety scores and others were collected. All data was gathered at the First Affiliated Hospital of Soochow University. The effects of pulmonary rehabilitation training on wedge resection and lobectomy were compared. RESULTS: A total of 210 patients were included in this study, including 126 patients with VATS wedge resection and 84 patients with VATS lobectomies. No discrepancy was noticed when FEV1 loss between two groups were compared in the wedge resection patients, and the same results were also shown in patients undergoing lobectomy (12.8% ± 2.0% vs. 12.7% ± 1.9%, P = 0.84, wedge resection; 12.6% ± 2.9% vs. 12.1% ± 1.8%, P = 0.37, lobectomy). The loss of FVC in the control group was greater than that in the rehabilitation group for patients undergoing lobectomy (11.7% ± 5.2%, vs. 17.1% ± 5.6%, P < 0.001, lobectomy). No difference was found in the wedge resection patients between the control and rehabilitation groups (6.6% ± 2.8%, vs. 6.4% ± 3.2%, P = 0.76, lobectomy). Moreover, all patients showed no significant difference in 6MWD regardless of surgical procedure and with or without breathing exercises at T3 (392.6 ± 50.6 m, rehabilitation group vs. 394.0 ± 46.6 m, control group. P = 0.87, wedge resection; 381.3 ± 38.9 m, rehabilitation group vs. 369.1 ± 49.3 m, control group. P = 0.21, lobectomy). CONCLUSIONS: For patients after thoracoscopic pulmonary wedge resection, the use of three-ball apparatus did not significantly improve postoperative pulmonary function and activity tolerance, dyspnea, and anxiety symptoms. In patients after thoracoscopic lobectomy, respiratory trainers were able to improve postoperative lung function but were unable to significantly improve dyspnea and anxiety symptoms. There was a significant benefit for the use of three-ball apparatus in patients after thoracoscopic lobectomy, whereas there was no significant benefit for the use of respiratory trainers after wedge resection. Registry: Medical Ethics Committee of the First Affiliated Hospital of Soochow University. REGISTRATION NUMBER: no. 2022455.

Accuracy and efficiency of digitally fabricated all-ceramic crowns from conventional impressions and intraoral scans: A single-blind clinical randomized controlled trial.

PURPOSE: To evaluate the accuracy of intraoral scanners by comparing the marginal fit of 70 all-ceramic crowns fabricated from both conventional impressions and intraoral scans. MATERIALS AND METHODS: A total of 70 posterior teeth requiring single-crown restorations randomly underwent either intraoral scanning or conventional impression-taking followed by laboratory scanning of the casts in a parallel-group RCT. Subsequently, 70 monolithic all-ceramic crowns were CAD/CAM fabricated; only the impression technique differed. Marginal fit, internal fit, adjustment time required for insertion and occlusal contacts, and visual analog scale (VAS) scores assessing dentists' satisfaction with all of the crowns were clinically evaluated by a blinded and calibrated examiner. Data were analyzed using independent-samples t test and likelihood ratio test or Fisher exact test. All tests were performed with α = .05. RESULTS: The mean marginal fit with intraoral scanning (57.94 ± 22.51 µm) was better than with diagnostic cast scanning (82.98 ± 21.72 µm). The difference was statistically significant (P = .000). The differences in internal fit, adjustment time for crown insertion and occlusal contacts, and VAS scores were also significant, and the secondary outcomes were in favor of intraoral scanning. CONCLUSION: Within the limitations of this clinical trial, CAD/CAM-fabricated single-tooth restorations in the posterior region produced by an intraoral scanning technique using TRIOS was found to be a more accurate and efficient alternative to restorations based on conventional impressions in combination with the laboratory scanning technique.

Polystyrene nanoplastics shape microbiome and functional metabolism in anaerobic digestion.

Nanoplastics (NPs) and microplastics (MPs) are ubiquitous in the natural environment, social production, and life. However, our understanding of the effects of NPs and MPs on shaping the microbiome and functional metabolism of anaerobic microorganisms is limited. We investigated the response of core microbiomes and functional genes to polystyrene (PS) NPs and MPs exposure in a representative anaerobic micro-ecosystem of waste activated sludge. Independent anaerobic digestion (AD) experiment indicated that PS nanobeads suppressed acidogenesis by inhibiting the activity of acetate kinase, and subsequently reduced methane production. Our findings confirmed that MPs (1 and 10 µm) had no perceptible effect on methane production, yet 50 nm NPs resulted in a 15.5% decrease in methane yield, perhaps driven by the behavior of dominant genera Sulfurovum, Candidatus Methanofastidiosum, and Methanobacterium. Assays revealed that NPs contributed to the simplest network assemblies in bacterial communities, contrary to empirical networks in archaeal communities. NPs significantly reduced the abundance of genes involved in carbon degradation: lig, naglu and xylA, as well as gcd and phnK related to phosphorus cycling. The absolute abundance of mcrA encoding methyl-coenzyme M reductase was 54.4% of the control assay. PS NPs might adversely affect the biodiversity and biogeochemical cycles in natural and artificial ecosystems through their negative impact on biomass energy conversion by anaerobic microorganisms.

A novel Pickering emulsion system as the carrier of tocopheryl acetate for its application in cosmetics.

Pickering emulsion (PE) stabilized by bio-compatible polymer nanoparticles (NPs) was first developed for the encapsulation of lipophilic tocopheryl acetate (TA) for its application in cosmetics. The poly(lactide-co-glycolide) (PLGA)/poly(styrene-co-4-styrene-sulfonate) (PSS) NPs were prepared by solvent displacement, and then they were used as emulsifier particles to fabricate TA-encapsulated PE. It was found that the TA encapsulation efficiency was >98%. Scanning electron microscope analysis showed that the obtained PE exhibited 'shell' structure. The PE droplets had spherical shape with diameter around 2 µm and good dispersibility as evidenced by laser scanning confocal microscope. In addition, the PE was stable at the pH range of 4.29-7.07 which was compatible to skin pH. Meanwhile, the PE also showed good storage stability since there was no obvious change in its diameter, PDI and TA retention after storage at 4 °C for 30 days. The DPPH method confirmed that TA retained its antioxidation in the PE preparation process. Moreover, an improved UV irradiation stability was observed for the TA after being encapsulated in the PE. The results of cytotoxicity test suggested that the PE was compatible to the Hacat cell line (human immortalized keratinocytes). And there is negligible influence in the cellular uptake of TA after its encapsulation in the PE. However, the cellular antioxidant activity (CAA) of encapsulated TA presented a significant increase from 1.32 to 1.56 µM quercetin equivalent/mg·mL-1. Hence, the prepared PE was promising as the carrier of TA for its cosmetic application.

Development of a polysaccharide based multi-unit nanofiber mat for colon-targeted sustained release of salmon calcitonin.

Advances in pharmaceutical technology have promoted the development of colon-targeted delivery system for oral administration of bioactive peptides or proteins to enhance their bioavailability. In this study, a multi-unit nanofiber mat was fabricated by coaxial electrospinning and its feasibility as the colon-targeted delivery system for a bioactive peptide, salmon calcitonin (sCT), was investigated. Sodium alginate and sCT-loaded liposome coated with pectin served as the shell layer and core layer, respectively. An in vitro study demonstrated that the encapsulated sCT was released in a sustained and colon-targeted way. Analysis using different mathematical models showed that release followed a complex mechanism. In addition, greater amounts of sCT were released from the core-shell nanofiber mat into simulated colon fluid (SCF) than was released from a uniaxial nanofiber mat (65.2% vs. 47.8%). The use of a core-shell nanofiber mat further alleviated the burst release of sCT into simulated gastric and intestinal fluid (SGF and SIF), demonstrating the superiority of a multi-unit vehicle for colon-targeted delivery of sCT. Furthermore, 88% of the bioactivity of encapsulated sCT was retained. This multi-unit vehicle offers a better-designed vehicle for the colon-targeted sustained release of bioactive peptides or proteins and, thus, should improve oral bioavailability.

Improved Viability and Thermal Stability of the Probiotics Encapsulated in a Novel Electrospun Fiber Mat.

For the enhancement of the probiotics' survivability, a nanostructured fiber mat was developed by electrospinning. The probiotic Lactobacillus plantarum was encapsulated in the nanofibers with fructooligosaccharides (FOS) as the cell material. Fluorescence microscope image and scanning electron microscopy (SEM) showed that viable cells were successfully encapsulated in nanofibers (mean diameter = 410 ± 150 nm), and the applied voltage had no significant influence on their viability ( P > 0.05). A significantly improved viability (1.1 log) was achieved by incorporating 2.5% (w/w) of FOS as the electrospinning material ( P < 0.001). Additionally, compared with free cells, the survivability of cells encapsulated in electrospun FOS/PVA/ L. plantarum nanofibers was significantly enhanced under moist heat treatment (60 and 70 °C). This study shows that the obtained nanofiber is a feasible entrapment structure to improve the viability and thermal stability of encapsulated probiotic cells and provides an alternative approach for the development of functional food.

Fabrication of electrospun polylactic acid nanofilm incorporating cinnamon essential oil/ß-cyclodextrin inclusion complex for antimicrobial packaging.

A novel antimicrobial packaging material was obtained by incorporating cinnamon essential oil/ß-cyclodextrin inclusion complex (CEO/ß-CD-IC) into polylacticacid (PLA) nanofibers via electrospinning technique. The CEO/ß-CD-IC was prepared by the co-precipitation method and SEM and FT-IR spectroscopy analysis indicated the successful formation of CEO/ß-CD-IC, which improved the thermal stability of CEO. The CEO/ß-CD-IC was then incorporated into PLA nanofibers by electrospinning and the resulting PLA/CEO/ß-CD nanofilm showed better antimicrobial activity compared to PLA/CEO nanofilm. The minimum inhibitory concentration (MIC) of PLA/CEO/ß-CD nanofilm against Escherichia coli and Staphylococcus aureus was approximately 1 mg/ml (corresponding CEO concentration 11.35 µg/ml) and minimum bactericidal concentration (MBC) was approximately 7 mg/ml (corresponding CEO concentration 79.45 µg/ml). Furthermore, compared with the casting method, the mild electrospinning process was more favorable for maintaining greater CEO in the obtained film. The PLA/CEO/ß-CD nanofilm can effectively prolong the shelf life of pork, suggesting it has potential application in active food packaging.

[The influences of non-surgical periodontal treatment on gingival crevicular fluid levels of MMP-8 and tissue inhibitor of TIMP-1].

PURPOSE: To compare the levels of MMP-8 and TIMP-1 in the gingival crevicular fluid (GCF)of chronic periodontitis(CP) patients before and after non-surgical periodontal therapy. METHODS: Sulcus bleeding index (SBI), plaque index (PLI) and probing depth (PD) were detected before and after therapy. GCF was collected from CP patients before and after therapy. MMP-8 and TIMP-1 were determined by enzyme-linked immunoabsorbent assay. The data was analyzed using paired-sample t test and multi-correlation analysis with SSPS 19.0 software package. RESULTS: The levels of MMP-8 and TIMP-1 decreased after therapy, and there was no significant difference in the MMP-8/TIMP-1 ratio. Correction analysis showed that a significant correction was found between MMP-8 and GCF weight. CONCLUSIONS: MMP-8 and TIMP-1 decrease after non-surgical periodontal therapy.

Chirality plays critical roles in enhancing the aqueous solubility of nocathiacin I by block copolymer micelles.

OBJECTIVES: Although drug solubilization by block copolymer micelles has been extensively studied, the rationale behind the choice of appropriate block copolymer micelles for various poorly water-soluble drugs has been of relatively less concern. The objective of this study was to use methoxy-poly(ethylene glycol)-polylactate micelles (MPEG-PLA) to solubilize glycosylated antibiotic nocathiacin I and to compare the effects of chirality on the enhancement of aqueous solubility. METHODS: Nocathiacin I-loaded MPEG-PLA micelles with opposite optical property in PLA were synthesized and characterized. The drug release profile, micelle stability and preliminary safety properties of MPEG-PLA micelles were evaluated. Meanwhile, three other poorly water-soluble chiral compound-loaded micelles were also prepared and compared. KEY FINDINGS: The aqueous solubility of nocathiacin I was greatly enhanced by both L- and D-copolymers, with the degree of enhancement appearing to depend on the chirality of the copolymers. Comparison of different chiral compounds confirmed the trend that aqueous solubility of chiral compounds can be more effectively enhanced by block copolymer micelles with specific stereochemical configuration. CONCLUSIONS: The present study introduced chiral concept on the selection and preparation of block copolymer micelles for the enhancement of aqueous solubility of poorly water-soluble drugs.

[A scanning electron microscope study on resin bonding amalgam restoration in cavity].

PURPOSE: To detect the bonding interface of resin bonding amalgam restoration(BAR) with scanning electron microscope(SEM). METHODS: Sixty-five healthy teeth were divided into 4 groups, including one control group(5 teeth) with regular amalgam restoration and 3 experimental groups (20 teeth each) with 3 kinds of resin bond agent. The section was detected with SEM to evaluate the resin-bonding-amalgam interface. RESULTS: The resin bonding agent could fulfill the micro-leakage between amalgam and enamel or dentin, and seal the dentin tubules completely. The resin bonding agent could bond enamel, dentin and amalgam well. The chemical curing agent had a better effect than the light curing agent. CONCLUSIONS: BAR reduces the micro-leakage around amalgam restoration and provides a better way to prevent secondary caries. Supported by Research Fund for Young Researches from Bureau of Health of Shanghai Municipality (Grant No.2007Y03).

[Correlation between single nucleotide polymorphism and periodontitis susceptibility in Shanghai Chinese patients].

PURPOSE: To investigate the correlation between 12 single nucleotide polymorphisms (SNPs) from 7 genes and periodontitis of susceptibility in Shanghai Chinese patients. METHODS: Genotypes of randomly grouped 50 health control subjects and 48 patients with chronic periodontitis were genotyped by MALDI-TOF MS detection system. A questionnaire, medical history, family history, signs, laboratory tests, treatment, follow-up information were collected. Statistical analysis of Chi-square test was performed using SPSS13.0 software package. RESULTS: In the screening of the 12 target SNPs,the GG genotype of rs2891168 correlated significantly with periodontitis, OR=3.071(95%CI:1.018-9.260,P=0.046). CONCLUSION: The GG genotype of rs2891168 may correlate significantly with periodontitis of Shanghai Chinese patients and further studies are needed to verify this finding. Supported by Natural Science Foundation of Shanghai Municipality (Grant No.10ZR1425900) and Research Fund of Bureau of Health of Shanghai Municipality (Grant No.2009202).