Self-Assembly of Peptide-Lipid Nanoparticles for the Efficient Delivery of Nucleic Acids.

A transfection formulation is successfully developed to deliver nucleic acids by adding an auxiliary lipid (DOTAP) to the peptide, and the transfection efficiency of pDNA reaches 72.6%, which is close to Lipofectamine 2000. In addition, the designed KHL peptide-DOTAP complex exhibits good biocompatibility by cytotoxicity and hemolysis analysis. The mRNA delivery experiment indicates that the complex had a 9- or 10-fold increase compared with KHL or DOTAP alone. Intracellular localization shows that KHL/DOTAP can achieve good endolysosomal escape. Our design provides a new platform for improving the transfection efficiency of peptide vectors.

Comparison of the dimensional and morphological accuracy of three-dimensional digital dental casts digitized using different methods.

The purpose of this study was to compare the accuracy of digital dental casts from plaster cast scanning (PCS), impression scanning (IPS), intraoral scanning (IOS), and cone-beam computed tomography (CBCT) scanning (CCS) methods. The maxillary and mandibular dental casts of 15 patients who needed CBCT scans for oral examination or treatment were digitized via four methods. 12 linear distance measurements of all digital dental casts were selected and acquired with software and compared to those of the reference plaster cast to evaluate the dimensional accuracy. Three-dimensional deviation analysis of the IPS, IOS and CCS groups with respect to the reference PCS group was performed to evaluate the morphological accuracy. The discrepancy in linear distances between the digital dental casts and reference plaster casts was statistically significant (p < 0.01). The dimensional accuracies of the PCS (0.06 ± 0.12 mm) and IPS (0.03 ± 0.05 mm) casts were better than those of the IOS (0.37 ± 0.30 mm) and CCS (0.54 ± 0.40 mm) casts. The one-sample t test showed that there were statistically significant differences between the discrepancies in 8 of the linear distances for the PCS group and 9 of the linear distances for the IPS group between the digital dental casts and reference plaster casts, with an ideal error of 0.00 (p < 0.05). The sequence of morphological accuracy from good to poor was maxillary and mandibular IPS, mandibular IOS; maxillary IOS; and maxillary and mandibular CCS. The accuracy of the digital dental casts from the PCS and IPS methods was greater than that of IOS and CCS methods. Although accuracy of the digital dental cast from IOS was low, it satisfied the clinical requirements for fixed restorations in small units. The accuracy of the digital dental cast from CCS was poorest and could only be used for procedures with lower accuracy requirements.

Pickering Emulsions Stabilized by Lignin/Chitosan Nanoparticles for Biphasic Enzyme Catalysis.

In this study, we construct a green and high-performance platform using Pickering emulsions for biphasic catalysis. The oil-in-water Pickering emulsions stabilized by the lignin/chitosan nanoparticles (Lig/Chi NPs) have great stability and alkali resistance, showing pH-responsive reversible emulsification and demulsification which can be recycled at least three times. The Pickering emulsion also has fluorescence and wide availability to different oil-to-water volume ratios, types of oil, storage times, temperatures, and ion concentrations. When this system is applied to the lipase-catalyzed reaction for the hydrolysis of p-nitrophenol palmitate, it will provide stable and large oil-water reaction interface areas, and the negatively charged lipase will enrich at the emulsion interface by electrostatic adsorption of the positively charged Lig/Chi NPs to achieve immobilization (lipase-Lig/Chi NPs). The reaction conversion rate can reach nearly 100% in 30 min, which is nearly three times higher than that of the conventional two-phase system. Moreover, the lipases in Pickering emulsion stabilized by Lig/Chi NPs exhibit great recyclability because of the protection of Lig/Chi NPs.

D-aspartic acid protects against gingival fibroblasts inflammation by suppressing pyroptosis.

BACKGROUND: Peri-implantitis is the main cause of dental implant failure, which is associated with pyroptosis. The roles of D-aspartic acid (D-Asp) on pyroptosis and the mechanism of the protective effect of D-Asp on human gingival fibroblasts (HGFs) remain unknown. This study investigated the effects of D-Asp on the pyroptosis of HGFs induced by high mobility group box 1 protein (HMGB1). METHODS: The cytotoxic effects of D-Asp on HGFs was detected by Cell Counting Kit-8 assay, the membrane permeability was investigated by propidium iodide/ Hoechst 33,342 double staining, flow cytometry analysis, and lactate dehydrogenase releasing, The gene and protein expression levels were detected by real-time quantitative PCR, enzyme-linked immunosorbent assay, and Western blot, respectively. RESULTS: Cell viability analysis showed that D-Asp ≤ 30 mM had no cytotoxicity to HGFs. HMGB1 drastically raised the membrane permeability of HGFs, while 1/10/30 mM D-Asp suppressed the permeability and remained the integrity of the membrane. HMGB1 promoted the mRNA expression of NLRP3, caspase-1, GSDMD, IL-1ß, and IL-18, and the protein expression of IL-1ß, IL-18, caspase-1, GSDMD, and NLRP3. CONCLUSIONS: With the pretreatment of HGFs with D-Asp of 1/10/30 mM for 24 h, the cell membrane permeability was reduced and the expression of NLRP3, caspase-1, GSDMD, IL-1ß, and IL-18 was significantly decreased compared with the HMGB1 group, indicating the competitive antagonism of D-Asp against HMGB1 on the binding with toll-like receptors. Hence, this study may provide a novel insight into preventing pyroptosis and propose a new strategy for the treatment of peri-implantitis.

Comparison of the accuracy (trueness and precision) of virtual dentofacial patients digitized by three different methods based on 3D facial and dental images.

STATEMENT OF PROBLEM: The accuracy of virtual dentofacial patients has been explored, but the accuracy of virtual patients established by using a straightforward and reliable method and the accuracy of different virtual patients are unclear. PURPOSE: The purpose of this clinical study was to compare the accuracy of virtual dentofacial patients digitized by using registered-block impression, exposed anterior teeth, and cone beam computed tomography (CBCT) reconstruction methods based on 3-dimensional (3D) facial and dental images. MATERIAL AND METHODS: From the 15 selected participants who needed CBCT scanning, 3 kinds of virtual dentofacial patients were established by using 3 registration methods based on digital dental casts: 3D facial images, CBCT data, and registered-block impression. Compared with actual measurement, 25 linear distances of all virtual dentofacial patients were selected and measured by using a software program, and 3 separate measurements were calculated by the same person. The 1-way analysis of variance (ANOVA) was used to compare the deviations among 3 kinds of virtual dentofacial patients (trueness) and the deviations within groups (precision). The 1-sample t test was used to compare the difference between the deviation and the ideal error of 0.00 (α=.05). RESULTS: Compared with the actual measurement, the trueness of the average deviations for registered-block impression (1.02 ±1.24 mm) was better than that of exposed anterior teeth (2.35 ±1.71 mm) and CBCT reconstruction (2.86 ±1.61 mm). The precision of the average deviations for registered-block impression (1.29 ±1.43 mm) was better than that of exposed anterior teeth (2.00 ±1.72 mm) and CBCT reconstruction (2.12 ±1.94 mm). Significant differences in trueness and precision were found among the 3 groups of virtual dentofacial patients (P<.01). Significant differences among the deviations of all linear distances and the ideal error of 0.00 were observed for all groups of virtual dentofacial patients (P<.05). CONCLUSIONS: The accuracy of registered-block impression was better than that of the exposed anterior teeth and CBCT reconstruction. The accuracy of exposed anterior teeth was lower than that of the other methods but could satisfy the requirements of clinical diagnostics and scientific methods. The accuracy of CBCT reconstruction was poor and could only be used for special situations that permitted low accuracy.

Fully digital workflow for the design and manufacture of prostheses for maxillectomy defects.

A fully digital workflow for the design and manufacture of prostheses for maxillectomy defects was described. Three-dimensional images from spiral computed tomography and intraoral scanning were used to generate a three-dimensional digital cast of a maxillectomy defect. The obturator prosthesis was then designed on the digital cast by combining dental computer-aided design and reverse engineering software programs. The prosthesis was subsequently milled from polyetheretherketone or three-dimensional-printed from polylactic acid.

A digital workflow for single complete denture using a multi-functional diagnostic denture.

Creating a single complete denture against natural dentition can be challenging. To facilitate the clinical procedure and promote balanced occlusion, we developed a digital workflow of a single complete denture using a multi-functional diagnostic denture (DD). The DD was digitally designed and fabricated using a three-dimensional printing process to create a guide for tooth grinding in opposing dentition and a final impression that allows the jaw relationship and dynamic articulation to be recorded by an intraoral scanner. The definitive complete denture was combined with a milled artificial dentition and titanium-plated denture base. Within three clinical visits, this digital workflow provided better efficiency and easy implementation for a single complete denture.

Advanced Hydrogel systems for mandibular reconstruction.

Mandibular defect becomes a prevalent maxillofacial disease resulting in mandibular dysfunctions and huge psychological burdens to the patients. Considering the routine presence of oral contaminations and aesthetic restoration of facial structures, the current clinical treatments are however limited, incapable to reconstruct the structural integrity and regeneration, spurring the need for cost-effective mandibular tissue engineering. Hydrogel systems possess great merit for mandibular reconstruction with precise involvement of cells and bioactive factors. In this review, current clinical treatments and distinct mode(s) of mandible formation and pathological resorption are summarized, followed by a review of hydrogel-related mandibular tissue engineering, and an update on the advanced fabrication of hydrogels with improved mechanical property, antibacterial ability, injectable form, and 3D bioprinted hydrogel constructs. The exploration of advanced hydrogel systems will lay down a solid foundation for a bright future with more biocompatible, effective, and personalized treatment in mandibular reconstruction.

Advances and Prospects in Antibacterial-Osteogenic Multifunctional Dental Implant Surface.

In recent years, dental implantation has become the preferred protocol for restoring dentition defects. Being the direct contact between implant and bone interface, osseointegration is the basis for implant exerting physiological functions. Nevertheless, biological complications such as insufficient bone volume, poor osseointegration, and postoperative infection can lead to implant failure. Emerging antibacterial-osteogenic multifunctional implant surfaces were designed to make up for these shortcomings both during the stage of forming osseointegration and in the long term of supporting the superstructure. In this mini-review, we summarized the recent antibacterial-osteogenic modifications of the dental implant surface. The effects of these modifications on biological performance like soft tissue integration, bone osteogenesis, and immune response were discussed. In addition, the clinical findings and prospects of emerging antibacterial-osteogenic implant materials were also discussed.

D-arginine Enhances the Effect of Alpha-Amylase on Disassembling Actinomyces viscosus Biofilm.

Peri-implantitis is the leading cause of dental implant failure, initially raised by biofilm accumulation on the implant surface. During the development of biofilm, Actinomyces viscosus (A. viscosus) plays a pivotal role in initial attachment as well as the bacterial coaggregation of multispecies pathogens. Hence, eliminating the A. viscosus-associated biofilm is fundamental for the regeneration of the lost bone around implants. Whereas clinical evidence indicated that antimicrobials and debridement did not show significant effects on the decontamination of biofilm on the implant surface. In this study, alpha-amylase was investigated for its effects on disassembling A. viscosus biofilm. Then, in order to substantially disperse biofilm under biosafety concentration, D-arginine was employed to appraise its enhancing effects on alpha-amylase. In addition, molecular dynamics simulations and molecular docking were conducted to elucidate the mechanism of D-arginine enhancing alpha-amylase. 0.1-0.5% alpha-amylase showed significant effects on disassembling A. viscosus biofilm, with definite cytotoxicity toward MC3T3-E1 cells meanwhile. Intriguingly, 8 mM D-arginine drastically enhanced the eradication of A. viscosus biofilm biomass by 0.01% alpha-amylase with biosafety in 30 min. The exopolysaccharides of biofilm were also thoroughly hydrolyzed by 0.01% alpha-amylase with 8 mM D-arginine. The biofilm thickness and integrity were disrupted, and the exopolysaccharides among the extracellular matrix were elusive. Molecular dynamics simulations showed that with the hydrogen bonding of D-arginine to the catalytic triad and calcium-binding regions of alpha-amylase, the atom fluctuation of the structure was attenuated. The distances between catalytic triad were shortened, and the calcium-binding regions became more stable. Molecular docking scores revealed that D-arginine facilitated the maltotetraose binding process of alpha-amylase. In conclusion, these results demonstrate that D-arginine enhances the disassembly effects of alpha-amylase on A. viscosus biofilm through potentiating the catalytic triad and stabilizing the calcium-binding regions, thus providing a novel strategy for the decontamination of biofilm contaminated implant surface.

In vivo and in simulated body fluid degradation behavior and biocompatibility evaluation of anodic oxidation-silane-chitosan-coated Mg-4.0Zn-0.8Sr alloy for bone application.

With the development and progress of science and technology, magnesium and magnesium alloys have attracted more and more researchers' attention because of their excellent biocompatibility. However, rapid degradation rate of magnesium alloy in vivo seriously limits its application (Arthanari et al., n.d.; Cui et al., 2013 [1,2]). In order to solve this problem, the surface modification of Mg-4.0Zn-0.8Sr alloy was adopted in this paper. According to the requirements of orthopedic materials, anodizing coating (AO), silane coating (SA) and chitosan coating (CS) coating were prepared on its surface, and magnesium alloy was prepared into intramedullary nail, and the corrosion resistance and biocompatibility of the corresponding samples was evaluated. The experimental results show that the AO-SA-CS coating sample has higher corrosion resistance, in addition, it also shows good biocompatibility, such as lower hemolysis rate and normal platelet adhesion morphology. After implantation into the femur, the femur of rats recovered well and the kidney tissue was normal.

Freeze-Casting with 3D-Printed Templates Creates Anisotropic Microchannels and Patterned Macrochannels within Biomimetic Nanofiber Aerogels for Rapid Cellular Infiltration.

A new approach is described for fabricating 3D poly(ε-caprolactone) (PCL)/gelatin (1:1) nanofiber aerogels with patterned macrochannels and anisotropic microchannels by freeze-casting with 3D-printed sacrificial templates. Single layer or multiple layers of macrochannels are formed through an inverse replica of 3D-printed templates. Aligned microchannels formed by partially anisotropic freezing act as interconnected pores between templated macrochannels. The resulting macro-/microchannels within nanofiber aerogels significantly increase preosteoblast infiltration in vitro. The conjugation of vascular endothelial growth factor (VEGF)-mimicking QK peptide to PCL/gelatin/gelatin methacryloyl (1:0.5:0.5) nanofiber aerogels with patterned macrochannels promotes the formation of a microvascular network of seeded human microvascular endothelial cells. Moreover, nanofiber aerogels with patterned macrochannels and anisotropic microchannels show significantly enhanced cellular infiltration rates and host tissue integration compared to aerogels without macrochannels following subcutaneous implantation in rats. Taken together, this novel class of nanofiber aerogels holds great potential in biomedical applications including tissue repair and regeneration, wound healing, and 3D tissue/disease modeling.

Microplastics in water, sediment and fish from the Fengshan River system: Relationship to aquatic factors and accumulation of polycyclic aromatic hydrocarbons by fish.

The occurrence of microplastics was investigated in water, sediment and fish from the Fengshan River system. All collected samples contained microplastics with 334-1058 items/m3 in the water samples, 508-3987 items/kg dry weight in the sediment samples and 14-94 items/fish in the fish samples. The spatial distribution of microplastics in water and sediments was attributed to anthropogenic discharges, flow dynamics, tidal exchanges and microplastic density. This was evidenced by significant correlations of microplastics with the river pollution index (RPI), chemical oxygen demand (COD), suspended solid (SS), flow velocity and the presence of different polymer types of microplastics in water and sediment. Microplastic abundance in fish was correlated to SS, pH and conductivity, indicating that these water quality variables might affect bioavailability of microplastics to fish. Concentrations of microplastics/cm length of demersal fish at a higher trophic level (Leiognathus equulus and Pomadasys argenteus) were higher than those of a benthopelagic fish (Oreochromis niloticus niloticus). The significant relationships observed suggest that collected fish might prefer to ingest long fibrous microplastics from sediments and large fragmented microplastics from water. The high levels of 3- and 4-ring polycyclic aromatic hydrocarbons (PAHs), particularly fluoranthene and pyrene, in fish muscle revealed that the collected fish species might have a high ability to accumulate these PAHs from food and the environment. Significant relationships between some PAHs in fish and microplastic abundances in water/sediments/fish suggested that these PAHs might be accumulated by fish from contaminated microplastics. This study provides unique information on the factors influencing the spatial distribution of microplastics and the role of microplastics on the accumulation of PAHs by fish.

Mitigating nutrient accumulation with microalgal growth towards enhanced nutrient removal and biomass production in an osmotic photobioreactor.

Forward osmosis (FO) has great potential for low energy consumption wastewater reuse provided there is no requirement for draw solutes (DS) regeneration. Reverse solute flux (RSF) can lead to DS build-up in the feed solution. This remains a key challenge because it can cause significant water flux reduction and lead to additional water quality problems. Herein, an osmotic photobioreactor (OsPBR) system was developed to employ fast-growing microalgae to consume the RSF nutrients. Diammonium phosphate (DAP) was used as a fertilizer DS, and algal biomass was a byproduct. The addition of microalgae into the OsPBR proved to maintain water flux while reducing the concentrations of NH4+-N, PO43--P and chemical oxygen demand (COD) in the OsPBR feed solution by 44.4%, 85.6%, and 77.5%, respectively. Due to the forward cation flux and precipitation, intermittent supplements of K+, Mg2+, Ca2+, and SO42- salts further stimulated algal growth and culture densities by 58.7%. With an optimal hydraulic retention time (HRT) of 3.33 d, the OsPBR overcame NH4+-N overloading and stabilized key nutrients NH4+-N at âˆ¼ 2.0 mg L-1, PO43--P < 0.6 mg L-1, and COD < 30 mg L-1. A moderate nitrogen reduction stress resulted in a high carbohydrate content (51.3 ± 0.1%) among microalgal cells. A solids retention time (SRT) of 17.82 d was found to increase high-density microalgae by 3-fold with a high yield of both lipids (9.07 g m-3 d-1) and carbohydrates (16.66 g m-3 d-1). This study encourages further exploration of the OsPBR technology for simultaneous recovery of high-quality water and production of algal biomass for value-added products.