SPION-Decorated Nanofibers by RAFT-Mediated Free Radical Emulsion Polymerization-Induced Self Assembly.

RAFT-mediated free-radical emulsion polymerization is successfully used to synthesize polystyrene nanofibers using triblock amphiphilic macro-RAFT copolymers as stabilizers. The polymerization is under RAFT control, producing various morphologies from spherical particles, nanofibers, nanoplatelets, and polymer vesicles. Optimum conditions are established for the synthesis of predominantly negatively charged polymer nanofibers. Superparamagnetic iron oxide nanoparticles (SPION)-decorated nanofibers are formed by simple mixing of the SPIONs with the fibers at an appropriate pH. The composite material has been found to be superparamagnetic and could be aligned under a magnetic field.

Mandibular Implant-Supported Overdentures Using Telescopic Crowns and Immediate Loading Protocol: A 2-Year Prospective Follow-up Study.

PURPOSE: Implant-supported overdentures have been an effective treatment method for edentulous mandibles. However, the loading time after implant placement is still controversial. The purpose of this study was to evaluate the outcome of implant-supported overdentures using telescopic crowns for the treatment of edentulous patients with immediate loading protocol. MATERIALS AND METHODS: This study was conducted on 22 edentulous mandibular patients visiting the Department of High Technique, National Hospital of Odonto - Stomatology, Ho Chi Minh City, Vietnam for prosthodontic rehabilitation. Each patient received four interforaminal implants. Immediate loading protocol was applied, and Ankylos Syncone copings systems was used to connect the prosthesis and the implants. The survival rate of implants and prostheses, as the primary outcome, were evaluated at 6 months, 01 year, and 02 years post-surgery. Peri-implant tissue condition, peri-implant bone loss, and patient satisfaction were the secondary outcomes. RESULTS: The implant survival rate was 98.9% with 01 failed implant. The peri-implant bone loss changes after 6 months, 01 year, and 02 years were 0.07 ± 0.22 mm, 0.12 ± 0.3 mm, and 0.15 ± 0.2 mm, respectively. No gingival hyperplasia was recorded. The prosthesis survival rate was 86.4% with 1 fractured overdenture, 1 overdenture relining and 1 abutment fracture. CONCLUSIONS: Mandibular rehabilitation using implant-supported overdenture with telescopic crowns and immediate loading protocol showed high survival rates of both implant and prosthesis in 2-year follow-up.

Tropoelastin modulates systemic and local tissue responses to enhance wound healing.

Wound healing is facilitated by biomaterials-based grafts and substantially impacted by orchestrated inflammatory responses that are essential to the normal repair process. Tropoelastin (TE) based materials are known to shorten the period for wound repair but the mechanism of anti-inflammatory performance is not known. To explore this, we compared the performance of the gold standard Integra Dermal Regeneration Template (Integra), polyglycerol sebacate (PGS), and TE blended with PGS, in a murine full-thickness cutaneous wound healing study. Systemically, blending with TE favorably increased the F4/80+ macrophage population by day 7 in the spleen and contemporaneously induced elevated plasma levels of anti-inflammatory IL-10. In contrast, the PGS graft without TE prompted prolonged inflammation, as evidenced by splenomegaly and greater splenic granulocyte and monocyte fractions at day 14. Locally, the inclusion of TE in the graft led to increased anti-inflammatory M2 macrophages and CD4+T cells at the wound site, and a rise in Foxp3+ regulatory T cells in the wound bed by day 7. We conclude that the TE-incorporated skin graft delivers a pro-healing environment by modulating systemic and local tissue responses. STATEMENT OF SIGNIFICANCE: Tropoelastin (TE) has shown significant benefits in promoting the repair and regeneration of damaged human tissues. In this study, we show that TE promotes an anti-inflammatory environment that facilitates cutaneous wound healing. In a mouse model, we find that inserting a TE-containing material into a full-thickness wound results in defined, pro-healing local and systemic tissue responses. These findings advance our understanding of TE's restorative value in tissue engineering and regenerative medicine, and pave the way for clinical applications.

Development and Characterization of Quercetin-Loaded Polymeric Liposomes with Gelatin-Poly(ethylene glycol)-Folic Acid Coating to Increase Their Long-Circulating and Anticancer Activity.

Liposomes as drug-delivery systems have been researched and applied in multiple scientific reports and introduced as patented products with interesting therapeutic properties. Despite various advantages, this drug carrier faces major difficulties in its innate stability, cancer cell specificity, and control over the release of hydrophobic drugs, particularly quercetin, a naturally derived drug that carries many desirable characteristics for anticancer treatment. To improve the effectiveness of liposomes to deliver quercetin by tackling and mitigating the mentioned hurdles, we developed a strategy to establish the ability to passively target cancerous cells, as well as to increase the bioavailability of loaded drugs by incorporating poly(ethylene glycol), gelatin, and folic acid moieties to modify the liposomal system's surface. This research developed a chemically synthesized gelatin, poly(ethylene glycol), and folic acid as a single polymer to coat drug-loaded liposome systems. Liposomes were coated with gelatin-poly(ethylene glycol)-folic acid by electrostatic interaction, characterized by their size, morphology, ζ potential, drug loading efficiency, infrared structures, differential scanning calorimetry spectra, and drug-releasing profiles, and then evaluated for their cytotoxicity to MCF-7 breast cancer cells, as well as cellular uptake, analyzed by confocal imaging to further elaborate on the in vitro behavior of the coated liposome. The results indicated an unusual change in size with increased coating materials, followed by increased colloidal stability, ζ potential, and improved cytotoxicity to cancer cells, as shown by the cellular viability test with MCF-7. Cellular uptake also confirmed these results, providing data for the effects of biopolymer coating, while confirming that folic acid can increase the uptake of liposome by cancer cells. In consideration of such results, the modified gelatin-poly(ethylene glycol)-folic acid-coated liposome can be a potential system in delivering the assigned anticancer compound. This modified biopolymer showed excellent properties as a coating material and should be considered for further practical applications in the future.

How metal augments, polyethylene thickness and stem length affect tibial baseplate load transfer in revision total knee arthroplasty.

BACKGROUND: It is unclear howmetal augments,polyethylene (PE) liner thickness, and length of cemented stemcontribute to load transferwhen reconstructing uncontained tibial metaphyseal bone loss of Anderson Orthopedic Research Institute (AORI) Type II defects during revision total knee arthroplasty (rTKA).The aimof this study is to understand the impact of these three variableson load transfer through the tibial baseplate. For a fixed defect depth, we hypothesized that there is a particular combination of liner and augment thickness and stem length that minimizes bone stress, reducing the risk of aseptic loosening. METHODS: We conducted a finite element analysis (FEA) to model stresses at the bone-cement interface with different iterations of metal augments, PE liner thicknesses andfully-cemented stems lengths. RESULTS: For a 20 mm tibial defect, constructs with thicker metal augments and thinner polyethylene liners were superior. Constructswith a fully cemented stem further reduced bone stress on the tibial plateau. Bone stress was lowest when a 100 mm fully-cemented stem was used, while stems between 30 mm - 80 mm produced similar results. CONCLUSIONS: When addressing a tibial bone defect of AORI Type II in rTKA, our FEA model demonstrates that surgeons should opt to use the thickest metal augments in combination with afully-cemented stem with an added length of at least 30 mm, which allows for surgical flexibility together with the most stable construct.Our study is notably limited by lack of modeling of knee joint moments, which are important when considering micromotion, bone-implant interface and stem effectiveness.

Effect of Posterior Residual Ridge Resorption and Relining for Mandibular Implant Overdentures on Bending Strain Around Implants.

PURPOSE: To examine the influence of posterior residual ridge resorption (PRRR) and relining on bending strain around implants under an overdenture. MATERIALS AND METHODS: Maxillary and mandibular edentulous models were made and covered with white silicone. Four strain gauges were placed on four sides of each implant. Two tissue-level implants were placed bilaterally in the part between the lateral incisors and canines of the mandible. A maxillary conventional denture and a mandibular overdenture were fabricated to fit the models. Three levels of bone resorption around the implant were created: 0, 0.8, and 1.5 mm. The surface of the residual ridge was uniformly removed from the area near the distal side of the implant to the retromolar section, and three levels of PRRR were created (0, 1, and 1.5 mm). After the measurement, the experimental denture of the PRRR of 1 mm and 1.5 mm were relined. Locator attachments were used. A 98-N occlusal force was applied, and bending strains around the implant were measured. The Kruskal-Wallis test and Bonferroni correction were employed to analyze the data. RESULTS: Without relining, at each bone resorption level around the implant, the bending strain was smallest with PRRR of 0 mm and largest with PRRR of 1.5 mm. The bending strain after relining was smaller than the bending strain with ridge resorption. Bending strains after relining were smaller than bending strains with no ridge resorption, but there was no significant difference in bending strain between these three groups. CONCLUSION: As PRRR increased, the bending strain increased without relining. As bone resorption around the implant progressed, PRRR enhanced the increase in the peri-implant bending strain. Bending strain was reduced when relining was performed.

Effect of the Features of Mandibular Implant Overdenture Attachments on the Bending Strain Around Implants.

PURPOSE: To examine the effect of the attachment features (abutment height, retention, and freedom of rotation) of implant overdentures on the bending strain around implants under an overdenture. MATERIALS AND METHODS: Mandibular and maxillary edentulous models were fabricated and covered with silicone rubber. Strain gauges were attached to the four sides of each implant. Two implants (tissue-level implant, 4.1-mm diameter, 10-mm length) were placed bilaterally in the area between the mandibular canines and lateral incisors. A maxillary conventional denture and a mandibular overdenture were made to fit the edentulous models. Three levels of peri-implant bone resorption were created sequentially: no bone resorption, 0.8 mm, and 1.5 mm. Three kinds of attachments (magnetic, stud, and ball attachments) were used. Bending strains generated from a 98-N occlusal load through the maxillary denture were measured using a sensor interface, and the data were analyzed using the Kruskal-Wallis and Bonferroni tests. Multiple regression analysis was used to find the relationship between independent variables (peri-implant bone resorption level, abutment height, retention, and freedom of rotation) and the dependent variable (bending strain). RESULTS: For all attachment types, the bending strains were smallest with no bone resorption and largest with 1.5-mm bone resorption (P < .05). Multiple regression analysis showed that abutment height had the greatest impact on the reduction of bending strain (beta = .413), followed by freedom of rotation (beta = -.349), and retention (beta = .107). CONCLUSION: Low abutment height, large freedom of rotation, and low retention can minimize bending strain around implants.

Average rate of ridge resorption in denture treatment: A Systematic Review.

Purpose To clarify the rate of posterior residual ridge resorption (PRRR) in different denture treatments and the factors that can affect PRRR.Study selection A bibliographical electronic search was conducted on MeSH, Web of Science, and Ovid databases. Hand searching was also conducted. Longitudinal studies recording the average rate of PRRR in the mandible were included. The effect size was calculated based on the mean rate of PRRR with standard deviation and group size. The random-effects analysis was used to perform meta-analyses across qualified studies.Results A total of 2245 eligible studies were collected from the MeSH, Web of Science, and Ovid databases and hand searching. In the end, 19 studies met the inclusion criteria and were extracted. The average rate of PRRR in different mandibular denture treatments was assessed in this systematic review. The mean combined effect size was -1.05 ± 0.5 (95% confidence interval [CI]: -3.18-1.08) between four-implant overdentures and two-implant overdentures. The combined effect size was -0.01 ± 0.22 (95% CI: -0.93-0.82) between complete dentures and two-implant overdentures. Body mass index, number of dentures used, denture wearing habit, impression technique, artificial tooth material, and peri-implant bone resorption showed no significant effect on the rate of PRRR. Gender, denture material, and relining frequency showed a significant effect on the rate of PRRR.Conclusions This review summarized different average rates of PRRR in mandibular denture treatments. Meta-analyses have reported that four-implant overdenture treatments can lower the rate of PRRR compared to two-implant overdenture treatments. However, there was no significant difference in the treatment effect between the complete denture and two-implant overdenture treatments.

The First Vietnamese Patient of LEOPARD Syndrome due to a PTPN11 Mutation: A Case Report and Review of the Literature.

LEOPARD syndrome is a rare congenital anomaly that involves several organs. Patients with this syndrome develop multiple lentigines resembling a leopard's hide. LEOPARD is an acronym of the major features constituting the syndrome including lentigines, electrocardiographic conduction defects, ocular hypertelorism, pulmonary valve stenosis, anomalies of genitalia, retardation of growth, and deafness. The syndrome is rare, and only 200 cases have been reported yet worldwide. We present the case of an 8-year-old female patient who visited the Ho Chi Minh City Hospital of Dermato-Venereology because of multiple brownish-black "dots" on her face and body. On examination, she also showed abnormalities in the maxillofacial bones, vertebrae, shoulders, sternum, and teeth, as well as deaf-mutism and growth retardation, which are typical of LEOPARD syndrome. Genetic analysis revealed a PTPN11 gene mutation in this case. To the best of our knowledge, this is the first case of LEOPARD syndrome reported in Vietnam.

Atom transfer radical-polymerized cationic shells on gold nanoparticles for near infrared-triggered photodynamic therapy of tumor-bearing animals.

Gold nanoparticles (AuNPs) were surface-engineered with a cationic corona to enhance the incorporation of photosensitizers for photodynamic therapy (PDT). The cationic corona composed of poly(2-(dimethylamino)ethyl methacrylate) was atom transfer radical-polymerized on the surface of the AuNPs. The cationic corona of the engineered surface was characterized by dynamic light scattering, electron microscopy, Raman spectroscopy, and mass spectroscopy. Chlorin-e6 (Ce6) incorporated onto the surface-engineered AuNPs exhibited higher cell incorporation efficiency than bare AuNPs. Ce6-incorporated AuNPs were confirmed to release singlet oxygen upon NIR irradiation. Compared to Ce6, Ce6-incorporated AuNPs exhibited higher cellular uptake and cytotoxicity against cancer cells in an irradiation time-dependent manner. Near-infrared-irradiated animals administered Ce6-incorporated AuNPs exhibited higher levels of tumor suppression without noticeable body weight loss. This result was attributed to the higher localization of Ce6 at the tumor sites to induce cancer cell apoptosis. Thus, we envision that engineered AuNPs with cationic corona can be tailored to effectively deliver photosensitizers to tumor sites for photodynamic therapy.

Invasive Mycobacterium abscessus Outbreak at a Pediatric Dental Clinic.

BACKGROUND: Mycobacterium species, specifically M. abscessus and M. chelonae (MABs), are known to contaminate water systems and are uncommon causes of health care-associated infection, but morbidity can be significant and treatment complex. METHODS: Odontogenic MAB infections occurred in patients following pulpotomy procedures at dental clinic A from 1 January to 6 September 2016. We identified confirmed and probable cases using culture data, imaging, pathology results, and surgical findings. Epidemiologic and clinical data including demographics, symptoms, laboratory findings, treatment regimens, and outcomes were extracted. RESULTS: Of 1082 at-risk patients, 71 case patients (22 confirmed; 49 probable) were identified. Median age was 6 years. Median symptom onset was 85 days postpulpotomy. Pain and/or swelling on admission occurred in 79%. On imaging, 49 of 70 had abnormalities of the mandible or maxilla, 13 of 70 had lymphadenopathy, and 19 of 68 had pulmonary nodules. Seventy were hospitalized (average of 8.5 days). Intravenous antibiotics were administered to 32 cases for a median length of 137 days. Clofazimine was administered to 29 patients as part of their multidrug regimen. Antibiotic treatment was associated with many adverse effects. Treated children showed evidence of jaw healing with resolved/improving pulmonary nodules at 1-year follow-up. CONCLUSIONS: This is the largest outbreak of invasive MAB infections associated with a pediatric dental practice. While infections were indolent, patients suffered medical and surgical consequences of treatment, including permanent tooth loss. Identification of this outbreak led to a change in water standards for pediatric dental procedures in California. Enhanced national dental water quality standards are needed to prevent future outbreaks.

Preparation of Stretchable Nanofibrous Sheets with Sacrificial Coaxial Electrospinning for Treatment of Traumatic Muscle Injury.

Traumatic muscle injury with massive loss of muscle volume requires intramuscular implantation of proper scaffolds for fast and successful recovery. Although many artificial scaffolds effectively accelerate formation and maturation of myotubes, limited studies are showing the therapeutic effect of artificial scaffolds in animal models with massive muscle injury. In this study, improved myotube differentiation is approved on stepwise stretched gelatin nanofibers and applied to damaged muscle recovery in an animal model. The gelatin nanofibers are fabricated by a two-step process composed of co-axial electrospinning of poly(ɛ-caprolactone) and gelatin and subsequent removal of the outer shells. When stepwise stretching is applied to the myoblasts on gelatin nanofibers for five days, enhanced myotube formation and polarized elongation are observed. Animal models with volumetric loss at quadriceps femoris muscles (>50%) are transplanted with the myotubes cultivated on thin and flexible gelatin nanofiber. Treated animals more efficiently recover exercising functions of the leg when myotubes and the gelatin nanofiber are co-implanted at the injury sites. This result suggests that mechanically stimulated myotubes on gelatin nanofiber is therapeutically feasible for the robust recovery of volumetric muscle loss.

Comparison Study of the Effects of Cationic Liposomes on Delivery across 3D Skin Tissue and Whitening Effects in Pigmented 3D Skin.

Charged phospholipids are employed to formulate liposomes with different surface charges to enhance the permeation of active ingredients through epidermal layers. Although 3D skin tissue is widely employed as an alternative to permeation studies using animal skin, only a small number of studies have compared the difference between these skin models. Liposomal delivery strategies are investigated herein, through 3D skin tissue based on their surface charges. Cationic, anionic, and neutral liposomes are formulated and their size, zeta-potential, and morphology are characterized using dynamic light scattering and cryogenic-transmission electron microscopy (cryo-TEM). A Franz diffusion cell is employed to determine the delivery efficiency of various liposomes, where all liposomes do not exhibit any recognizable difference of permeation through the synthetic membrane. When the fluorescence liposomes are applied to 3D skin, considerable fluorescence intensity is observed at the stratum cornea and epithelium layers. Compared to other liposomes, cationic liposomes exhibit the highest fluorescence intensity, suggesting the enhanced permeation of liposomes through the 3D skin layers. Finally, the ability of niacinamide (NA)-incorporated liposomes to suppress melanin transfer in pigmented 3D skin is examined, where cationic liposomes exhibit the highest degree of whitening effects.

The influence of bone loss on peri-implant bending strain under overdentures.

PURPOSE: The purpose of this study was to evaluate the biomechanical effects of bone loss on peri-implant bending strain underneath overdentures. MATERIALS AND METHODS: One mandibular and one maxillary edentulous model were created and covered with 2 to 4 mm of silicone rubber to simulate the oral mucosa. Four strain gauges were attached to four sides of each implant. In the mandibular model, two implants were inserted, and the implant was placed bilaterally in the area between the mandibular canines and lateral incisors. A maxillary conventional denture and mandibular overdenture were fabricated with acrylic resin to fit the edentulous models. Five bone loss levels were created: no bone loss, 0.8 mm bone loss on only the left implant, 0.8 mm bone loss bilaterally, 1.5 mm bone loss on only the left implant, and 1.5 mm bone loss bilaterally. Magnetic attachments were used to retain the denture. The bending strains generated from three types of unilateral loading were measured by a sensor interface, and the data were analyzed using the Kruskal-Wallis test and Bonferroni's post hoc test. RESULTS: Bending strain increased with decreasing bone levels on the loading side. On the nonloading side, bending strains were greater at even bone loss (0.8 mm or 1.5 mm bone loss bilaterally) than at uneven bone loss (0.8 mm or 1.5 mm bone loss on only the left implant). Strains under loading at the left first premolar were approximately equal to that under loading with a cotton roll; these strains were higher than those generated with loading at the left first molar. CONCLUSION: Peri-implant bending strains rapidly increased on the loading side as bone loss levels increased. Peri-implant bending strains on the nonloading side were higher at bilaterally even bone loss than at unilateral bone loss.

Lysozyme depolymerization of photo-activated chitosan adhesive films.

Effective tissue bioadhesion of rose bengal-chitosan films can be achieved by photoactivation using a green laser. In this study, lysozyme was incorporated in these films to enhance the rate of depolymerization and assess the laser impact on lysozyme. The lysozyme loaded films exhibited a 21% mass loss after 4 weeks implantation in rats while control films (without lysozyme) had only 7% mass loss. Capillary electrophoresis-mass spectroscopy showed that chitosan degraded into monomers and oligomers of glucosamine and N-acetyl-glucosamine. Irradiation with laser did not affect the depolymerization of adhesive by lysozyme suggesting that the inclusion of lysozyme in the bioadhesive is a viable technique for tailoring the depolymerization.

Reversal of age-related deficient influenza virus-specific CTL responses and IFN-gamma production by monophosphoryl lipid A.

Old and young Balb/c mice, 24--26 and 2--4 months old, respectively, were infected with a 0.1 LD50 of influenza A/Taiwan/1/86 (A/H1N1) virus by small particle aerosol. Lung virus titers were determined 4, 6, 8, 12, and 17 days later. Old mice had significantly higher virus titers than young mice (P < 0.05-0.0001) and shed virus up to Day 17, while young mice were free of virus by Day 12. Splenic MHC class I CD8+ CTL activity (P < 0.08--0.001) and IFN-gamma production (0.1-0.008) measured on Days 8, 12, and 17 were significantly lower among old mice than among young mice. Coadministration of liposomal influenza vaccine with monophosphoryl lipid A (MPL) resulted in enhanced CD8+ CTL response and IFN-gamma production among old mice (35 and 12,000 times, respectively). These results demonstrate that MPL stimulates CTL and Th1 cytokines (IFN-gamma) in aged mice and may serve to reverse age-related CD8+ CTL deficiency and reduce severe influenza disease in elderly human populations.