[Evaluation of the effect of 3D printing resin splint based on the retention effect of orthodontic treatment in patients with periodontal disease].

PURPOSE: To investigate the difference in the retention effect of 3D printing resin splint and Hawley retainer combined with lingual retention wire in periodontal disease patients after orthodontic treatment. METHODS: Forty patients who finished orthodontic treatment for periodontal disease from January 2021 to February 2022 were selected and divided into experimental group and control group according to the random number table method, with 20 patients in each group. Patients in the experimental group used 3D printing resin splint for retention, while patients in the control group used Hawley retainer combined with a lingual retention wire for retention. The chair-side operation time of the retainers was recorded for both groups. The maxillary and mandibular cuspid width, molar width, overjet, overbite and irregularity index were measured at 1 month and 6 months after orthodontic treatment in both groups. Statistical analysis was performed with SPSS 12.0 software package. RESULTS: The mean time for chair-side manipulation of experimental group and control group was 8.23, 11.17 min, respectively. The difference between the two groups was statistically significant (P＜0.05) when comparing the width of the maxillary and mandibular cusps, the width of the molars, overjet, overbite and the irregularity index after 1 month and 6 months of wear of the retainers, which were significantly greater in the experimental group than in the control group at 6 months(P＜0.05). CONCLUSIONS: 3D printing resin splint, with short chair-side manipulation time, was more effective than Hawley retainer combined with a lingual retention wire, and the efficacy of both groups was otherwise generally consistent.

Intelligent and thermo-responsive Au-pluronic® F127 nanocapsules for Raman-enhancing detection of biomolecules.

Thermo-responsive Raman-enhanced nanocapsules were successfully fabricated by Pluronic® F127 (F127) decorated with gold nanoparticles (AuNPs) for surface-enhanced Raman scattering (SERS) detection of biomolecules. F127 nanocapsules changes from hydrophilicity (swelling) to hydrophobicity (de-swelling) when the temperature increases from 15 °C to 37 °C, owing to the lower critical solution temperature (LCST) of F127 is about 26.5 °C. The size of nanocapsules would be enormous shrinking from 160 nm to 20 nm, resulting in a significant decrease in the distance between AuNPs to enhance hot spot effect, which increases the sensitivity of SERS detection. Based on the thermo-sensitive behavior, the ratio of AuNPs and F127 would be manipulated to find the optimal SERS enhancement effect. SERS nanocapsules can rapidly detect biomolecules (adenine and R6G) with limit of detection (LOD) lower than 10-6 M. In addition, the relatively difficult to detect clinical samples, carboxyl-terminal parathyroid hormone fragments (C-PTH), can also be measured by the thermo-responsive SERS nanocapsules developed in this work. It is expected the biomolecules can be adsorbed at low temperature (15 °C), as well as collected and concentrated at high temperature (37 °C) for SERS detection, to increase the sensitivity and stability of SERS detection.

Combustion kinetics and emission characteristics of polycyclic aromatic hydrocarbons from polylactic acid combustion.

This study investigates the combustion kinetics and emission factors of 16 U.S. Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs) in polylactic acid (PLA) combustion. Experimentally, two reactions are involved in the PLA combustion process that potentially result in the release of lactide, acetaldehyde, and n-hexaldehyde. The products may continuously be oxidized to form carbon dioxide (CO2) and some PAHs produced because of incomplete combustion. The analytical results indicate that the emission factors for PAHs are in the range of not detectable to 98.04 microg/g. The emission factors are much lower than those of poly(ethylene terephalate) (PET) and other combustion of plastics. Results from this work suggest that combustion is a good choice for waste PLA disposal.

Microwave-assisted production of CO2-activated biochar from sugarcane bagasse for electrochemical desalination.

A high-performance carbon electrode is desirable for promoting electrochemical desalination efficiency in the membrane capacitive deionization (MCDI). Sugarcane bagasse (food waste) was employed in this study to prepare hierarchically porous biochars by microwave-assisted carbonization and activation with potassium hydroxide in N2 or CO2 atmosphere under varying flow rates (100-600 cm3 min-1). The sugarcane bagasse-derived biochars activated under CO2 flow of 300 cm3 min-1 (denoted as SBB-CO2-300) possessed the ratio of mesopores to total pore volume (Vmeso/Vtotal) of 56.7% with a specific surface area of 1019 m2 g-1. The electrochemical behavior of SBB-CO2-300 was demonstrated by a surpassing specific capacitance of 208 F g-1 at 5 mV s-1 by means of cyclic voltammetry. The desalination tests using a batch-mode MCDI at 1.2 V in a 5 mM NaCl solution indicated that the SBB-CO2-300 electrode exhibited an excellent electrosorption capacity of 28.9 mg g-1. The improvement in the electrochemical deionization performance of SBB-CO2-300 was attributed to the superior Vmeso/Vtotal ratio, high surface area, excellent capacitance behavior, and hierarchical pore structure. The biowaste-derived biochars prepared via facile microwave-assisted carbonization and CO2 activation route can provide a sustainable and high-efficiency carbon electrode for electrochemical deionization of brackish water.

Novel bifurcation stents coated with bioabsorbable nanofibers with extended and controlled release of rosuvastatin and paclitaxel.

A novel bifurcation stent coated with bioabsorbable nanofibers that deliver the extended and controlled release of rosuvastatin and paclitaxel was developed. Bioabsorbable bifurcation stents, consisting of a double-slit tubular main body and two spiral branches, were manufactured. Bi-layered poly (lactic-co-glycolic acid) nanofibers that contained rosuvastatin and paclitaxel were used for treating the stents. Various properties of the fabricated stents, including compression strengths, collapse pressure, water contact angle and flow properties within a circulation model, were quantified. In vitro nanofibrous elution chromatography assays from the drug-loading bifurcation stents were carried out for the release patterns of pharmaceuticals. The effectiveness of eluted rosuvastatin and paclitaxel in inhibiting the adhesion of platelets as well as the proliferation of smooth muscle cells (SMCs) were studied, respectively. The experimental results suggest that bioabsorbable nanofibrous bifurcation stents released high concentrations of rosuvastatin and paclitaxel for 27 and 70 days, respectively. The eluted drugs of rosuvastatin and paclitaxel effectively reduced adherent platelets and the proliferation of SMCs. The developed bioabsorbable nanofibrous bifurcation stents herein may provide a promising means of treating cardiovascular bifurcation lesions.

Bio-inspired crosslinking and matrix-drug interactions for advanced wound dressings with long-term antimicrobial activity.

There is a growing demand for durable advanced wound dressings for the management of persistent infections after deep burn injuries. Herein, we demonstrated the preparation of durable antimicrobial nanofiber mats, by taking advantage of strong interfacial interactions between polyhydroxy antibiotics (with varying number of OH groups) and gelatin and their in-situ crosslinking with polydopamine (pDA) using ammonium carbonate diffusion method. Polydopamine crosslinking did not interfere with the antimicrobial efficacy of the loaded antibiotics. Interestingly, incorporation of antibiotics containing more number of alcoholic OH groups (NOH ≥ 5) delayed the release kinetics with complete retention of antimicrobial activity for an extended period of time (20 days). The antimicrobials-loaded mats displayed superior mechanical and thermal properties than gelatin or pDA-crosslinked gelatin mats. Mats containing polyhydroxy antifungals showed enhanced aqueous stability and retained nanofibrous morphology under aqueous environment for more than 4 weeks. This approach can be expanded to produce mats with broad spectrum antimicrobial properties by incorporating the combination of antibacterial and antifungal drugs. Direct electrospinning of vancomycin-loaded electrospun nanofibers onto a bandage gauze and subsequent crosslinking produced non-adherent durable advanced wound dressings that could be easily applied to the injured sites and readily detached after treatment. In a partial thickness burn injury model in piglets, the drug-loaded mats displayed comparable wound closure to commercially available silver-based dressings. This prototype wound dressing designed for easy handling and with long-lasting antimicrobial properties represents an effective option for treating life-threatening microbial infections due to thermal injuries.

Advanced interstitial chemotherapy combined with targeted treatment of malignant glioma in rats by using drug-loaded nanofibrous membranes.

Glioblastoma multiforme (GBM), the most prevalent and malignant form of a primary brain tumour, is resistant to chemotherapy. In this study, we concurrently loaded three chemotherapeutic agents [bis-chloroethylnitrosourea, irinotecan, and cisplatin; BIC] into 50:50 poly[(d,l)-lactide-co-glycolide] (PLGA) nanofibres and an antiangiogenic agent (combretastatin) into 75:25 PLGA nanofibres [BIC and combretastatin (BICC)/PLGA]. The BICC/PLGA nanofibrous membranes were surgically implanted onto the brain surfaces of healthy rats for conducting pharmacodynamic studies and onto C6 glioma-bearing rats for estimating the therapeutic efficacy.The chemotherapeutic agents were rapidly released from the 50:50 PLGA nanofibres after implantation, followed by the release of combretastatin (approximately 2 weeks later) from the 75:25 PLGA nanofibres. All drug concentrations remained higher in brain tissues than in the blood for more than 8 weeks. The experimental results, including attenuated malignancy, retarded tumour growth, and prolonged survival in tumour-bearing rats, demonstrated the efficacy of the BICC/PLGA nanofibrous membranes. Furthermore, the efficacy of BIC/PLGA and BICC/PLGA nanofibrous membranes was compared. The BICC/PLGA nanofibrous membranes more efficiently retarded the tumour growth and attenuated the malignancy of C6 glioma-bearing rats. Moreover, the addition of combretastatin did not significantly change the drug release behaviour of the BIC/PLGA nanofibrous membranes. The present advanced and novel interstitial chemotherapy and targeted treatment provide a potential strategy and regimen for treating GBM.

Oral Tori in Chronic Peritoneal Dialysis Patients.

BACKGROUND: The pathogenesis of oral tori has long been debated and is thought to be the product of both genetic and environmental factors, including occlusal forces. Another proposed mechanism for oral tori is the combination of biomechanical forces, particularly in the oral cavity, combined with cortical bone loss and trabecular expansion, as one might see in the early stages of primary hyperparathyroidism. This study investigated the epidemiology of torus palatinus (TP) and torus mandibularis (TM) in peritoneal dialysis patients, and analyzed the influences of hyperparathyroidism on the formation of oral tori. METHOD: In total, 134 peritoneal dialysis patients were recruited between July 1 and December 31, 2015 for dental examinations for this study. Patients were categorized into two subgroups based on the presence or absence of oral tori. Demographic, hematological, biochemical, and dialysis-related data were obtained for analysis. RESULTS: The prevalence of oral tori in our sample group was high at 42.5% (57 of 134), and most patients with oral tori were female (61.4%). The most common location of tori was TP (80.7%), followed by TP and TM (14.0%), then TM (5.3%). All 54 TP cases were at the midline, and most were <2 cm (59.3%), flat (53.7%), and located in the premolar region (40.7%). Of the 11 TM cases, all were bilateral and symmetric, mostly <2 cm (81.9%), lobular (45.4%), and located at premolar region (63.6%). Interestingly, patients with oral tori had slightly lower serum levels of intact parathyroid hormones than those without oral tori, but the difference was not statistically significant (317.3±292.0 versus 430.1±492.6 pg/mL, P = 0.126). In addition, patients with oral tori did not differ from patients without tori in inflammatory variables such as serum high sensitivity C-reactive protein levels (6.6±8.2 versus 10.3±20.2 mg/L, P = 0.147) or nutritional variables such as serum albumin levels (3.79±0.38 versus 3.77±0.45 g/dL, P = 0.790). Furthermore, there were no differences between patients with and without oral tori in dialysis adequacy (weekly Kt/Vurea, 2.14±0.39 versus 2.11±0.33, P = 0.533; weekly creatinine clearance rate, 59.31±17.58 versus 58.57±13.20 L/1.73 m2, P = 0.781), or peritoneal membrane transporter characteristics (P = 0.098). CONCLUSION: Secondary hyperparathyroidism does not contribute to the formation of tori in peritoneal dialysis patients. Further studies are warranted.

Interaction of gelatin with polyenes modulates antifungal activity and biocompatibility of electrospun fiber mats.

Topical application of antifungals does not have predictable or well-controlled release characteristics and requires reapplication to achieve therapeutic local concentration in a reasonable time period. In this article, the efficacy of five different US Food and Drug Administration-approved antifungal-loaded (amphotericin B, natamycin, terbinafine, fluconazole, and itraconazole) electrospun gelatin fiber mats were compared. Morphological studies show that incorporation of polyenes resulted in a two-fold increase in fiber diameter and the mats inhibit the growth of yeasts and filamentous fungal pathogens. Terbinafine-loaded mats were effective against three filamentous fungal species. Among the two azole antifungals compared, the itraconazole-loaded mat was potent against Aspergillus strains. However, activity loss was observed for fluconazole-loaded mats against all of the test organisms. The polyene-loaded mats displayed rapid candidacidal activities as well. Biophysical and rheological measurements indicate strong interactions between polyene antifungals and gelatin matrix. As a result, the polyenes stabilized the triple helical conformation of gelatin and the presence of gelatin decreased the hemolytic activity of polyenes. The polyene-loaded fiber mats were noncytotoxic to primary human corneal and sclera fibroblasts. The reduction of toxicity with complete retention of activity of the polyene antifungal-loaded gelatin fiber mats can provide new opportunities in the management of superficial skin infections.

Expansion of breast cancer stem cells with fibrous scaffolds.

Cancer stem cells (CSCs) are hypothesized as tumor-initiating cells within tumors and main contributors of tumor growth, metastasis and recurrence. Mammary cancer cells, MCF-7 cells, were cultured on 3D polycaprolactone (PCL) fibrous scaffolds, showing an increased proportion of CSCs. The expression of stem cell markers, including OCT3/4 and SOX2, and breast CSC-specific markers, SOX4 and CD49f, was significantly upregulated, and the mammosphere-forming capability in cells cultured on PCL fibrous scaffolds increased. The fibrous scaffolds also induced the elongation of MCF-7 cells and extended cell proliferation. The increase of CSC properties after being cultured on fibrous scaffolds was further confirmed with two luminal-type mammary cell lines, T47D and SK-BR-3, and a basal-type cell line, MDA-MB-231, by ALDEFLUOR assay and mammosphere formation assay. Moreover, we observed the upregulation of epithelial to mesenchymal transition and increased invasive capability in cells cultured on PCL fibrous scaffolds. These data suggest that the increase of CSC proportion in a 3D culture system may account for the enhanced malignancy. Therefore, our PCL fibrous scaffolds can potentially be used for CSCs enrichment and anti-cancer drug screening.

Dual functionalization of titanium with vascular endothelial growth factor and ß-defensin analog for potential application in keratoprosthesis.

Functionalization of material surfaces can improve their biointegration and bactericidal effect. To expand the biomedical applications of titanium in artificial cornea implantation surgery, titanium alloy substrates were coated with polydopamine and dual bound with recombinant vascular endothelial growth factor (VEGF) and anti-microbial peptide (AMP), SESB2V. Successful chemical binding was assessed with attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Coating thickness was assessed by atomic force microscopy. Cellular studies revealed that the functionalized substrates displayed the abilities to enhance primary human corneal fibroblast adhesion, proliferation, and viability. Angiogenesis assay with human mesenchymal stem cells was used to verify the biological functions of immobilized VEGF while bactericidal assay was evaluated for the anti-microbial activities of immobilized SESB2V peptide. We found that the titanium surface that was sequentially functionalized with VEGF and SESB2V had enhanced fibroblast proliferation and anti-microbial properties. The incorporation of such peptides into an artificial cornea implant is important for implant-tissue integration and wound healing. This may improve implant integration and reduce the risk of device infection following artificial cornea implantation.