Tetrahedral Framework Nucleic Acids Deliver Antimicrobial Peptides with Improved Effects and Less Susceptibility to Bacterial Degradation.

Antimicrobial peptides (AMPs) have been an attractive alternative to traditional antibiotics. However, considerable efforts are needed to further enhance their antimicrobial effects and stability against bacterial degradation. Tetrahedral framework nucleic acids (tFNAs), a new class of three-dimensional nanostructures, have been utilized as a delivery vehicle. In this study, tFNAs were combined for the first time with an antimicrobial peptide GL13K, and the effects of the resultant complexes against Escherichia coli (sensitive to GL13K) and Porphyromonas gingivalis (capable of degrading GL13K) were investigated. tFNA-based delivery enhanced the effects of GL13K against E. coli. The tFNA vehicle both increased bacterial uptake and promoted membrane destabilization. Moreover, it enhanced the effects of GL13K against P. gingivalis by protecting the peptide against degradation in the protease-rich extracellular environment. Therefore, tFNA provides a delivery vehicle for AMPs targeting a broad range of disease.

Effects of sterilization and disinfection methods on digitally designed surgical implant guide accuracy: An in vitro study.

INTRODUCTION: Surgical guides are commonly used to assist with dental implant placement. This study investigated the effects of five sterilization and disinfection methods on the accuracy of implant guides. METHODS: Thirty surgical guides (five in each group) were designed and printed (with digital light processing technology) using different sterilization or disinfection methods categorized into six groups: hydrogen peroxide sterilization (group one); glutaraldehyde sterilization (group two); autoclaving (group three); plasma sterilization (group four); iodophor disinfection (group five); and blank group (group six). Verification was determined using three methods: distance and angle between the cross-shaped marks, deformation after superimposing the guides, and displacement and axial changes in the virtual implant. RESULTS: After disinfection and sterilization, the guides in the autoclaving and iodophor groups showed a more pronounced color change and the guide in the autoclaving group had visible cracks. More significant changes were observed in the H2O2, glutaraldehyde, autoclaving, and iodophor groups regarding deformation after superimposing the guides and the distance and angle between the cross-shaped marks. The average labial deformation values (mm) of the first through fifth groups of guides were 0.283, 0.172, 0.289, 0.153, and 0.188, respectively. All groups were statistically different from the blank group for displacement and axial changes of the virtual implant (p < 0.05). CONCLUSION: The sizes of almost all surgical guides changed after sterilization and disinfection treatments, with between-group differences. Plasma sterilization was more suitable for surgical guide sterilization because of the smaller deformations after treatment.

Minimally invasive techniques for lateral maxillary sinus floor elevation: small lateral window and one-stage surgery-a 2-5-year retrospective study.

This study aimed to introduce a minimally invasive technique for maxillary sinus floor elevation using the lateral approach (lSFE) and to determine the factors that influence the stability of the grafted area in the sinus cavity. Thirty patients (30 implants) treated with lSFE using minimally invasive techniques from 2015 to 2019 were included in the study. Five aspects of the implant (central, mesial, distal, buccal, and palatal bone heights [BHs]) were measured using cone-beam computed tomography (CBCT) before implant surgery, immediately after surgery (T0), 6 months after surgery (T1), and at the last follow-up visit (T2). Patients' characteristics were collected. A small bone window (height, (4.40 ± 0.74) mm; length, (6.26 ± 1.03) mm) was prepared. No implant failed during the follow-up period (3.67 ± 1.75) years. Three of the 30 implants exhibited perforations. Changes in BH of the five aspects of implants showed strong correlations with each other and BH decreased dramatically before second-stage surgery. Residual bone height (RBH) did not significantly influence BH changes, whereas smoking status and type of bone graft materials were the potentially influential factors. During the approximate three-year observation period, lSFE with a minimally invasive technique demonstrated high implant survival rate and limited bone reduction in grafted area. In conclusion, lSFE using minimally invasive techniques was a viable treatment option. Patients who were nonsmokers and whose sinus cavity was filled with deproteinized bovine bone mineral (DBBM) had significantly limited bone resorption in grafted area.

A minimally invasive method for titanium mesh fixation with resorbable sutures in guided bone regeneration: A retrospective study.

OBJECTIVES: Titanium mesh has become a mainstream choice for guided bone regeneration (GBR) owing to its excellent space maintenance. However, the traditional fixation method using titanium screws impacts surgery efficiency and increases patient trauma. We report a novel method of fixing a titanium mesh using resorbable sutures. We assessed the feasibility of resorbable sutures for fixing a titanium mesh and whether it can serve as a stable, universal, and minimally invasive fixation method for a broader application of titanium meshes. METHODS: Patients undergoing GBR with a digital titanium mesh fixed using titanium screws (TS group) and resorbable sutures (RS group) were observed at different time points. The stability of the fixation methods was evaluated on parameters such as titanium mesh spatial displacement, bone augmentation, and bone resorption. RESULTS: A total of 36 patients were included in this study. The exposure rate of the titanium mesh in the TS group was 16.67%, while no exposure was noted in the RS group. There was no significant difference in the parameters of titanium mesh spatial displacement, bone augmentation, and bone resorption between the two groups (p > 0.05). CONCLUSION: The use of resorbable sutures for fixing a titanium mesh can achieve similar results to traditional fixation using titanium screws. Although this new fixation method can improve the efficiency of the surgery and reduce the risk of complications, the long-term clinical effects require further follow-up investigation.

Tetrahedral-Framework Nucleic Acids Carry Small Interfering RNA to Downregulate Toll-Like Receptor 2 Gene Expression for the Treatment of Sepsis.

Sepsis is caused by the invasion of pathogenic microorganisms, which can lead to excessive expression of toll-like receptors (TLRs) in cells and uncontrollable amplification of the inflammatory response. TLR2, as an essential part of the TLR family, has a significant feature in the identification of innate immune responses. Therefore, blocking the expression and activation of TLR2 can inhibit the synthesis and release of inflammatory factors and avoid the occurrence of excessive inflammatory reactions. Small interfering RNA (siRNA) can selectively target the silencing or downregulation of pathogenic genes and has the advantages of high specificity, a strong effect, and fewer adverse reactions. However, the application of siRNA is limited by its high molecular weight, poor biostability, and difficulty in passive uptake into cells. Tetrahedral-framework nucleic acid (tFNA) is a new kind of three-dimensional nucleic acid nanomaterial, which has the advantages of good biocompatibility, stable structure, and editability. In this study, we used tFNA as carriers to deliver siRNA-targeting downregulation of TLR2 expression for anti-inflammatory therapy. We show that siRNA can specifically reduce lipopolysaccharide (LPS)-induced TLR2 elevation and reduce release of inflammatory factors in LPS-induced experimental sepsis, which provides a new idea for the prevention and treatment of sepsis.

A novel digital and visualized guided bone regeneration procedure and digital precise bone augmentation: A case series.

BACKGROUND: Although the traditional bone augmentation technology can basically meet the clinical needs at present, the effect of bone augmentation in most cases is related to the experience of the operator. PROPOSE: This study commits to providing a digital solution for precise bone augmentation in the field of oral implantology. MATERIALS AND METHODS: After collecting the data of patients' intraoral scanning and DICOM (digital imaging and communications in medicine), the implant position is digitally designed, and the alveolar bone is digitally augmented around the ideal implant position. On the premise of ensuring that the thickness of labial bone is 2 mm, and there is sufficient alveolar bone 3 to 4 mm apically from the ideal gingival margin for implant placing, we carry out excessive augmentation of 0.5 and 1 mm on the labial bone and alveolar crest, respectively, to compensate for possible bone resorption after 6 months. After 3D printing the reconstructed alveolar bone model, the titanium mesh is trimmed and preformed on the alveolar bone model. Outcomes are reported in terms of mean values (5%-95% percentile values). RESULTS: Thirty implant sites have accepted this novel virtually designed alveolar bone augmentation. Before the second-stage surgery, the average vertical bone gain was 2.48 mm (0.29-6.32), the average horizontal bone gain was 4.11 mm (1.19-8.74), the average height of the residual alveolar bone above the implant platform was 1.44 mm (0.59-2.92), the average thickness of the labial bone width at the implant platform was 2.00 mm (0.93-3.64), the average thickness of the labial bone width at 2 mm apically from the implant platform was 2.74 mm (1.40-5.46). The virtual augmentation of each tooth position was 349.41 mm3 (165.70-482.70), while the actual augmentation of each tooth position was 352.94 mm3 (159.24-501.78), the accuracy of the final actual augmentation reached 95.82% (range from 88.53% to 99.15%). CONCLUSION: This case series suggests that a virtually digital guided bone regeneration (GBR) workflow is precise and controllable. The practicality, safety and effectiveness of this procedure needs to be compared to other bone augmentation procedures in randomized controlled trials.

The protective effect of tetrahedral framework nucleic acids on periodontium under inflammatory conditions.

Periodontitis is a common disease that causes periodontium defects and tooth loss. Controlling inflammation and tissue regeneration are two key strategies in the treatment of periodontitis. Tetrahedral framework nucleic acids can modulate multiple biological behaviors, and thus, their biological applications have been widely explored. In this study, we investigated the effect of tFNAs on periodontium under inflammatory conditions. Lipopolysaccharide and silk ligature were used to induce inflammation in vivo and in vitro. The results displayed that tFNAs decreased the release of pro-inflammatory cytokines and levels of cellular reactive oxygen species in periodontal ligament stem cells, which promoted osteogenic differentiation. Furthermore, animal experiments showed that tFNAs ameliorated the inflammation of the periodontium and protect periodontal tissue, especially reducing alveolar bone absorption by decreasing inflammatory infiltration and inhibiting osteoclast formation. These findings suggest that tFNAs can significantly improve the therapeutic effect of periodontitis and have the great potential significance in the field of periodontal tissue regeneration.

Titanium mesh for bone augmentation in oral implantology: current application and progress.

Guided bone regeneration (GBR) is an effective and simple method for bone augmentation, which is often used to reconstruct the alveolar ridge when the bone defect occurs in the implant area. Titanium mesh has expanded the indications of GBR technology due to its excellent mechanical properties and biocompatibility, so that the GBR technology can be used to repair alveolar ridges with larger bone defects, and can obtain excellent and stable bone augmentation results. Currently, GBR with titanium mesh has various clinical applications, including different clinical procedures. Bone graft materials, titanium mesh covering methods, and titanium mesh fixing methods are also optional. Moreover, the research of GBR with titanium mesh has led to multifarious progresses in digitalization and material modification. This article reviews the properties of titanium mesh and the difference of titanium mesh with other barrier membranes; the current clinical application of titanium mesh in bone augmentation; common complications and management and prevention methods in the application of titanium mesh; and research progress of titanium mesh in digitization and material modification. Hoping to provide a reference for further improvement of titanium mesh in clinical application and related research of titanium mesh.

Design, fabrication and applications of tetrahedral DNA nanostructure-based multifunctional complexes in drug delivery and biomedical treatment.

Although organic nanomaterials and inorganic nanoparticles possess inherent flexibility, facilitating functional modification, increased intracellular uptake and controllable drug release, their underlying cytotoxicity and lack of specificity still cause safety concerns. Owing to their merits, which include natural biocompatibility, structural stability, unsurpassed programmability, ease of internalization and editable functionality, tetrahedral DNA nanostructures show promising potential as an alternative vehicle for drug delivery and biomedical treatment. Here, we describe the design, fabrication, purification, characterization and potential biomedical applications of a self-assembling tetrahedral DNA nanostructure (TDN)-based multifunctional delivery system. First, relying on Watson-Crick base pairing, four single DNA strands form a simple and typical pyramid structure via one hybridization step. Then, the protocol details four different modification approaches, including replacing a short sequence of a single DNA strand by an antisense peptide nucleic acid, appending an aptamer to the vertex, direct incubation with small-molecular-weight drugs such as paclitaxel and wogonin and coating with protective agents such as cationic polymers. These modified TDN-based complexes promote the intracellular uptake and biostability of the delivered molecules, and show promise in the fields of targeted therapy, antibacterial and anticancer treatment and tissue regeneration. The entire duration of assembly and characterization depends on the cargo type and modification method, which takes from 2 h to 3 d.