Cobalt doped Prussian blue modified hollow polydopamine for enhanced antibacterial therapy.

Give the emergence of drug resistance in bacteria resulting from antibiotic misuse, there is an urgent need for research and application of novel antibacterial approaches. In recent years, nanoparticles (NPs) have garnered significant attention due to their potential to disrupt bacteria cellular structure through loading drugs and special mechanisms, thus rendering them inactive. In this study, the surface of hollow polydopamine (HPDA) NPs was utilized for the growth of Prussian blue (PB), resulting in the formation of HPDA-PB NPs. Incorporation of Co element during the preparation process led to partial doping of PB with Co2+ions. The performance test results demonstrated that the HPDA-PB NPs exhibited superior photothermal conversion efficiency and peroxidase-like activity compared to PB NPs. HPDA-PB NPs have the ability to catalyze the formation of hydroxyl radicals from H2O2in a weakly acidic environment. Due to the tiny PB particles on the surface and the presence of Co2+doping, they have strong broad-spectrum antibacterial properties. Bothin vitroandin vivoevaluations confirm their efficacy against various bacterial strains, particularlyStaphylococcus aureus, and their potential to promote wound healing, making them a promising candidate for advanced wound care and antimicrobial applications.

Programmatically Dynamic Microcompartmentation in Coacervate-in-Pickering Emulsion Protocell.

The desire for exploration of cellular functional mechanisms has substantially increased the rapid development of artificial cells. However, the construction of synthetic cells with high organizational complexity remains challenging due to the lack of facile approaches ensuring dynamic multi-compartments of cytoplasm and stability of membranes in protocells. Herein, a stable coacervate-in-Pickering emulsion protocell model comprising a membraneless coacervate phase formed by poly-l-lysine (PLys) and adenosine triphosphate (ATP) encapsulated in Pickering emulsion is put forward only through simple one-step emulsification. The dynamic distribution of intracellular components (coacervates in this protocell model) can be manipulated by changes in temperature or pH. This coacervate-in-Pickering emulsion protocell system exhibits repeatable cycle stability in response to external stimuli (at least 24 cycles for temperature and 3 cycles for pH). By encapsulating antagonistic enzymes into coacervates, glucose oxidase (GOx) and urease as an example, the control of local enzyme concentration is achieved by introducing glucose and urea to adjust the pH value in Pickering emulsion droplets. This hybrid protocell model with programmatically dynamic microcompartmentation and sufficient stability is expected to be further studied and applied in cellular biology, facilitating the development of lifelike systems with potential in practical applications.

Quadruple H-Bonding and Polyrotaxanes Dual Cross-linking Supramolecular Elastomer for High Toughness and Self-healing Conductors.

Tough and self-healable substrates can enable stretchable electronics long service life. However, for substrates, it still remains a challenge to achieve both high toughness and autonomous self-healing ability at room temperature. Herein, a strategy by using the combined effects between quadruple H-bonding and slidable cross-links is proposed to solve the above issues in the elastomer. The elastomer exhibits high toughness (77.3 MJ m-3 ), fracture energy (≈127.2 kJ m-2 ), and good healing efficiency (91 %) at room temperature. The superior performance is ascribed to the inter and intra crosslinking structures of quadruple H-bonding and polyrotaxanes in the dual crosslinking system. Strain-induced crystallization of PEG in polyrotaxanes also contributes to the high fracture energy of the elastomers. Furthermore, based on the dual cross-linked supramolecular elastomer, a highly stretchable and self-healable electrode containing liquid metal is also fabricated, retaining resistance stability (0.16-0.26 Ω) even at the strain of 1600 %.

B16F10 Cell Membrane-Based Nanovesicles for Melanoma Therapy Are Superior to Hyaluronic Acid-Modified Nanocarriers.

Some cancer cell membrane (CCM)-derived nanovesicles show strong homing effects and are used for targeted cancer therapy. By co-constructing the B16F10 cell membrane with a PEGylated phospholipid membrane, a new nanocarrier with a composite nanocrown structure was developed, which can evade immune recognition and actively target homologous melanoma. The nanocrowns have an encapsulation efficiency of more than 90% for paclitaxel and showed no significant difference (p > 0.05) from the PEGylated phospholipid membrane vesicles. Compared with the hyaluronic acid-modified PEGylated phospholipid membrane vesicles, the biomimetic nanocrowns enhanced the escape of nanovesicles from reticuloendothelial cells in vitro and extended the circulation time in vivo; moreover, the nanocrowns showed superior melanoma-targeted drug delivery capability and improved anticancer effects of paclitaxel as demonstrated by the inhibition of B16F10 cell proliferation and induction of apoptosis by interfering with microtubule formation. In contrast, the modification of hyaluronic acid did not increase the targeting capacity or antitumor effects of the nanocrowns, confirming that the superior targeting capacity was mediated by the exposed homologous CCMs rather than by hyaluronic acid. Our results demonstrate the potential of using biomimetic nanocrowns for active melanoma-targeted therapy.

SUCCESSFUL RESOLUTION OF NUTCRACKER SYNDROME WITH 3D PRINTED PEEK EXTRAVASCULAR STENT IN AN ADOLESCENT BOY.

Three-dimensional printed polyetheretherketone (PEEK) extravascular stent was applied to treat a 14-year-old boy with nutcracker syndrome. Digital subtraction angiography revealed a segment of the left renal vein (LRV) with reduced contrast filling immediately before its inflow into the inferior vena cava, and high-pressure gradient. The three-dimensional reconstruction model demonstrated that the LRV and the duodenum were contracted at the aortomesenteric angle, resulting in LRV compression from the abnormal high-level duodenal compartment. When duodenum courses between the abdominal aorta and superior mesenteric artery (duodenal interposition), the LRV entrapment occurs even at <90 aortomesenteric degrees. Three-dimensional printed PEEK extravascular stent was chosen to elevate the superior mesenteric artery and lower the duodenum position, thus relieving LRV compression. This extravascular application has significant advantages over open surgery, endovascular stenting and artificial vessel procedures with expanded polytetrafluoroethylene. It provides better cellular vitality by ensuring soft tissue proliferation. By reducing external acceleration and centrifugal force, a three-dimensional printed PEEK extravascular stent reduces adverse side effects. Such a stent has a distinctive personalized design, good stiffness, and durability that allows blood vessel growth, preventing stent migration and thrombosis. Therefore, it is suitable for both adult and pediatric patients. According to the abdominal ultrasound and multi-slice computed tomography scan, the postoperative follow-up results were satisfactory one year after surgery. The patient felt well, the blood flow in the LRV was not obstructed, and the blood flow velocity was average. The external stent was in place.

A novel pyrrole-imidazole polyamide targets Aurora kinase A and suppresses tumor growth in vivo.

Aurora kinase A (Aurora A) plays a critical role in regulating cell mitotic progression and has been considered as a promising drug target for cancer therapy. To develop a novel molecule targeting Aurora A with high selectivity and efficacy, we designed and synthesized a pyrrole-imidazole polyamide (PIP) Hoechst conjugate, PIP-Ht, targeting to a cell-cycle regulated DNA sequence locating at the promoter of human Aurora A gene (AURKA). PIP-Ht potently suppressed AURKA promoter activities, mRNA expression and protein level, induced tumor cell cycle delay and inhibited tumor cell proliferation in vitro. Furthermore, subcutaneous injection of PIP-Ht into mice bearing human cancer xenografts induced significant tumor growth suppression and cell apoptosis. Collectively, PIP-Ht exhibits the potential as an effective therapeutic candidate for the tumor treatment.

Substrate Engineering in Lipase-Catalyzed Selective Polymerization of d-/l-Aspartates and Diols to Prepare Helical Chiral Polyester.

The synthesis of optically pure polymers is one of the most challenging tasks in polymer chemistry. Herein, Novozym 435 (Lipase B from Candida antarctica, immobilized on Lewatit VP OC 1600)-catalyzed polycondensation between d-/l-aspartic acid (Asp) diester and diols for the preparation of helical chiral polyesters was reported. Compared with d-Asp diesters, the fast-reacting l-Asp diesters easily reacted with diols to provide a series of chiral polyesters containing N-substitutional l-Asp repeating units. Besides amino acid configuration, N-substituent side chains and the chain length of diols were also investigated and optimized. It was found that bulky acyl N-substitutional groups like N-Boc and N-Cbz were more favorable for this polymerization than small ones probably due to competitively binding of these small acyl groups into the active site of Novozym 435. The highest molecular weight can reach up to 39.5 × 103 g/mol (Mw, D = 1.64). Moreover, the slow-reacting d-Asp diesters were also successfully polymerized by modifying the substrate structure to create a "nonchiral" condensation environment artificially. These enantiocomplementary chiral polyesters are thermally stable and have specific helical structures, which was confirmed by circular dichroism (CD) spectra, scanning electron microscope (SEM), and molecular calculation.

A novel multi-functionalized multicellular nanodelivery system for non-small cell lung cancer photochemotherapy.

BACKGROUND: A red blood cell membrane (RBCm)-derived drug delivery system allows prolonged circulation of an antitumor treatment and overcomes the issue of accelerated blood clearance induced by PEGylation. However, RBCm-derived drug delivery systems are limited by low drug-loading capacities and the lack of tumor-targeting ability. Thus, new designs of RBCm-based delivery systems are needed. RESULTS: Herein, we designed hyaluronic acid (HA)-hybridized RBCm (HA&RBCm)-coated lipid multichambered nanoparticles (HA&RBCm-LCNPs) to remedy the limitations of traditional RBCm drug delivery systems. The inner core co-assembled with phospholipid-regulated glycerol dioleate/water system in HA&RBCm-LCNPs met the required level of blood compatibility for intravenous administration. These newly designed nanocarriers had a honeycomb structure with abundant spaces that efficiently encapsulated paclitaxel and IR780 for photochemotherapy. The HA&RBCm coating allowed the nanocarriers to overcome the reticuloendothelial system barrier and enhanced the nanocarriers specificity to A549 cells with high levels of CD44. These properties enhanced the combinatorial antitumor effects of paclitaxel and IR780 associated with microtubule destruction and the mitochondrial apoptotic pathway. CONCLUSIONS: The multifunctional HA&RBCm-LCNPs we designed expanded the functionality of RBCm and resulted in a vehicle for safe and efficient antitumor treatment.

A solid-phase microextraction fiber coating based on magnetic covalent organic framework for highly efficient extraction of triclosan and methyltriclosan in environmental water and human urine samples.

Herein, we synthesized a kind of magnetic covalent organic framework nanohybrids (NiFe2O4@COF), and integrated it with polydimethyl siloxane and silicone rubber curing agent for solid phase microextraction (SPME) fiber coating. The fiber coating demonstrated a porous and uniform surface with the BET specific surface of 169.7 m2 g-1. As for seven environmental analytes, the NiFe2O4@COF-based SPME fiber coating gave the higher extraction recoveries for triclosan (TCS) and methyltriclosn (MTCS) than those of fenpropathrin, bifenthrin, permethrin, fenvalerate and deltamethrin. Several operational parameters were rigorously optimized, such as extraction temperature, extraction time, thermal desorption time, solution pH and salt effect. Combined with the GC-ECD detection, the newly developed microextraction method supplied the wide linear range of 0.1-1000 µg L-1 with the correlation coefficients of > 0.9995. The limits of detection (LODs) and limits of quantitation (LOQs) reached as low as 1-7 ng L-1 and 3.3-23 ng L-1, respectively. The intra-day and inter-day precisions in six replicates (n = 6 ) were < 3.55% and < 5.06%, respectively, and the fiber-to-fiber reproducibility (n = 3) was < 7.64%. To evaluate its feasibility in real samples, the fortified recoveries for TCS and MTCS, at low (0.2 µg L-1), middle (2.0 µg L-1) and high (20.0 µg L-1) levels, varied between 81.9% and 119.1% in tap, river and barreled waters as well as male, female and children urine samples. Especially, it is worth mentioning that the NiFe2O4@COF-based SPME coating fiber can be recycled for at least 150 times with nearly unchanged extraction efficiency. Moreover, the extraction recoveries by the as-fabricated fiber coating were much higher than those by three commercial fibers (PDMS, PDMS/DVB and PDMS/DVB/CAR). Overall, the NiFe2O4@COF-based SPME is a convenient, sensitive, efficient and "green" pretreatment method, thereby possessing important application prospects in trace monitoring of TCS-like pollutants in complex liquid matrices.

Ultrasmall nanostructured drug based pH-sensitive liposome for effective treatment of drug-resistant tumor.

BACKGROUND: Cancer cells always develop ways to resist and evade chemotherapy. To overcome this obstacle, herein, we introduce a programmatic release drug delivery system that imparts avoiding drug efflux and nuclear transport in synchrony via a simple nanostructured drug strategy. RESULTS: The programmatic liposome-based nanostructured drugs (LNSD) contained two modules: doxorubicin (DOX) loaded into tetrahedral DNA (TD, ~ 10 nm) to form small nanostructured DOX, and the nanostructured DOX was encapsulated into the pH-sensitive liposomes. In the in vitro and in vivo studies, LNSD shows multiple benefits for drug resistance tumor treatment: (1) not only enhanced the cellular DOX uptake, but also maintained DOX concentration in an optimum level in resistant tumor cells via nanostructure induced anti-efflux effect; (2) small nanostructured DOX efficiently entered into cell nuclear via size depended nuclear-transport for enhanced treatment; (3) improved the pharmacokinetics and biodistribution via reducing DOX leakage during circulation. CONCLUSIONS: The system developed in this study has the potential to provide new therapies for drug-resistant tumor.

Transcutol® P/Cremophor® EL/Ethyl Oleate-Formulated Microemulsion Loaded into Hyaluronic Acid-Based Hydrogel for Improved Transdermal Delivery and Biosafety of Ibuprofen.

In the present study, a novel transdermal delivery system was developed and its advantages were demonstrated. Ibuprofen is a commonly used anti-inflammatory, antipyretic, and analgesic drug; however, because of its short biological half-life, it must be frequently administered orally and is highly irritating to the digestive tract. To prepare a novel transdermal delivery system for ibuprofen, a microemulsion was used as a drug carrier and dispersed in a hyaluronic acid-based hydrogel (ME/Gel) to increase percutaneous drug absorption while avoiding gastrointestinal tract irritation. The prepared microemulsion had a droplet size of ~ 90 nm, and the microemulsion had good stability in the hydrogel. Rheological tests revealed that the ME/Gel is a pseudoplastic fluid with decreased viscosity and increased shear rate. It displayed a certain viscoelasticity, and the microemulsion distribution displayed minor effects on the rheological characteristics of the hydrogel system. There was no significant difference in the rheology of the ME/Gel at 25°C and 32°C (normal skin surface temperature), which is beneficial for clinical application. Drug transdermal flux was significantly higher than that of the hydrogel and commercial cream groups (p < 0.01). The 24-h cumulative drug permeation amount was 1.42-fold and 2.52-fold higher than that of the hydrogel and cream groups, respectively. By loading into the ME/Gel, the cytotoxicity of the drug to HaCaT cells was reduced. These results indicate that the prepared ME/Gel can effectively improve transdermal ibuprofen delivery and the biosafety of the drug and could therefore have applicability as a drug delivery system.

A novel microemulsion-based isotonic perfusate modulated by Ringer's solution for improved microdialysis recovery of liposoluble substances.

BACKGROUND: Microdialysis is promising technique for dynamic microbiochemical sampling from tissues. However, the application of typical aqueous perfusates to liposoluble substances is limited. In this study, a novel microemulsion (ME)-based isotonic perfusate (RS-ME) was prepared to improve the recovery of liposoluble components using microdialysis probes. RESULTS: Based on pseudo-ternary phase diagrams and comparisons of the ME area, Kolliphor® EL and Transcutol® P were selected as the surfactant and co-surfactant, respectively, with a weight ratio (Km) of 2:1 and ethyl oleate as the oil phase. The ME was mixed with Ringer's solution at a 1:6 ratio (v/v) to obtain the isotonic RS-ME. The droplet size distribution of the ME in RS-ME was 78.3 ± 9.2 nm, with a zeta potential of - 3.5 ± 0.3 mV. By microdialysis perfusion, RS-ME achieved higher recovery rates of the poorly water-soluble compounds evodiamine (EVO) and ruthenium (RUT), i.e., 58.36 ± 0.57% and 49.40 ± 0.57%, respectively, than those of 20% (v/v) PEG 400 Ringer's solution (RS-PEG) and 10% (v/v) ethanol Ringer's solution (RS-EtOH). In vivo microdialysis experiments confirmed that RS-ME captured EVO and RUT molecules around the dialysis membrane more efficiently and exhibited less spreading than RS-PEG and RS-EtOH. CONCLUSIONS: Owing to the nanosized droplets formed by lipid components in the RS-ME and the limited dispersion out of the dialysis membrane, we obtained good biocompatibility and reliable dialysis results, without affecting the tissue microenvironment. As a novel perfusate, RS-ME provides an easy and reliable approach to the microdialysis sampling of fat-soluble components.

Fluoride induces apoptosis and autophagy through the IL-17 signaling pathway in mice hepatocytes.

Previous studies have reported that excessive fluoride exposure induced liver damage. However, the underlying mechanism of fluoride-induced hepatic toxicity is still unclear. Hence, this study was aimed to evaluate the fluoride-induced apoptosis, autophagy, and IL-17 signaling pathway-related genes to explore the possible mechanisms of NaF-induced liver injury in mice. For this, 48 male mice were allotted randomly to four groups, treated with deionized water, 25, 50, 100 mg/L NaF for 150 days continuously. Our results suggested that treatment with NaF decreased the PAS staining-positive area, with a concomitant increase in liver score, and serum ALT and AST levels which indicated that NaF induced the liver injury. In addition, the qRT-PCR, immunohistochemistry, and western blotting results indicated that NaF exposure activated IL-17 signaling, apoptosis, and autophagy pathways. In summary, these results suggested that NaF induced apoptosis and autophagy in liver by activating the IL-17 signaling pathway, eventually leading to impaired liver function.

Decoloration of waste PET alcoholysis liquid by an electrochemical method.

Disperse Red 60 simulated polyester alcoholysis liquid decoloration by electro-Fenton with Fe3O4 catalyst was studied. The influences of the main operating parameters such as catalyst dosage (0.3-0.9 g/L), current density (60-120 mA/cm2) and pH (1-7) were optimized by response surface methodology (RSM) based on Box-Behnken surface statistical design (BBD). In optimal conditions, the initial concentration of 25 mg/L disperse red polyester alcoholysis liquid was catalyzed by 0.6 g/L Fe3O4, and the decoloration efficiency was 97.18% with the current density of 90 mA/cm2 and initial pH of 4.6. There was a relative error of 1.18% with the predicted model when the predictive value was 98.25% under the same conditions. In addition, ultraviolet-visible absorption spectra (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to study the degradation mechanism during decoloration. The intermediates were identified and the proposed degradation pathways were investigated by liquid chromatography-mass spectrometry (LC-MS) analysis.

Modified nanoparticle mediated IL-12 immunogene therapy for colon cancer.

For the past few years, immunotherapy has recently shown considerable clinical benefit in CRC therapy, and the application of immunologic therapies in cancer treatments continues to increase perennially. Interleukin-12, an ideal candidate for tumor immunotherapy, could activate both innate and adaptive immunities. In this study, we developed a novel gene delivery system with a self-assembly method by MPEG-PLA and DOTAP(DMP) with zeta-potential value of 38.5mV and size of 37.5nm. The supernatant of lymphocytes treated with supernatant from Ct26 transfected pIL12 with DMP could inhibit Ct26 cells growth ex vivo. Treatment of tumor-bearing mice with DMP-pIL12 complex has significantly inhibited tumor growth at both the subcutaneous and peritoneal model in vivo by inhibiting angiogenesis, promoting apoptosis and reducing proliferation. The IL-12 plasmid and DMP complex may be used to treat the colorectal cancer in clinical as a new drug.

Solvent-Free Lipase-Catalyzed Synthesis: Unique Properties of Enantiopure D- and L- Polyaspartates and Their Complexation.

Amino acids are attractive monomers for the large-scale preparation of chiral polyamides. For enzymatic polymerization of amino acids using protease in aqueous environment as the catalysis system, one main restriction is oligomer formation, usually along with other displayed advantages. Herein we developed an efficient solvent-free lipase-catalyzed polymerization of diethyl D- or L-aspartate, providing chiral D- and L-polyaspartates with an average degree of polymerization (DPavg) up to 60 and having about 96% ß-linkages. Additionally, their distinct chemical and physical properties were characterized by circular dichroism (CD) spectra, X-ray powder diffraction (XRD), microscopic observation, and thermal analysis. Poly(ß-D-AspEt) and Poly(ß-L-AspEt) showed vertically mirrored negative and positive CD signals, high crystallinity, and entirely different microscopic morphology. They are thermal stable while having different decomposition (Td), melting (Tm), and cold crystallization temperatures (Tcc), respectively. Our results also showed that the complexation of enantiopure D- and L-polyaspartates was not stereocomplex but homocomplex.

Doping hydroxylated cationic lipid into PEGylated cerasome boosts in vivo siRNA transfection efficacy.

The therapeutic application of small interfering RNA (siRNA) requires safe nanocarriers for specific and efficient delivery in vivo. Herein, PEGylated cationic cerasomes (PCCs) were fabricated by doping a cationic lipid with a hydroxyl group into nanohybrid cerasomes. Multiple properties of PCCs provide a solution to many of the limitations associated with current platforms for the delivery of siRNA. The polyorganosiloxane surface imparts PCCs with higher morphological stability than conventional liposomes. The PEGylation of the cationic cerasome could protect the cerasome nanoparticles from agglomeration and macrophage capture, reduce protein absorption, and consequently prolong the blood circulating time and enhance the siRNA delivery efficiency. In addition, incorporation of the lipid containing a hydroxyl group further facilitates endosome release. Moreover, PCCs were further used to transport siRNA into the cytosol primarily via endocytosis. When applied to systemic administration, PCCs have demonstrated effective delivery into the liver and preferential uptake by hepatocytes in mice, thereby leading to high siRNA gene-silencing activity. All these results show potential therapeutic applications of PCCs-mediated delivery of siRNA for liver diseases.

Coxsackievirus B3 HFMD animal models in Syrian hamster and rhesus monkey.

Coxsackievirus B3 (CVB3) is the pathogen causing hand, foot and mouth disease (HFMD), which manifests across a spectrum of clinical severity from mild to severe. However, CVB3-infected mouse models mainly demonstrate viral myocarditis and pancreatitis, failing to replicate human HFMD symptoms. Although several enteroviruses have been evaluated in Syrian hamsters and rhesus monkeys, there is no comprehensive data on CVB3. In this study, we have first tested the susceptibility of Syrian hamsters to CVB3 infection via different routes. The results showed that Syrian hamsters were successfully infected with CVB3 by intraperitoneal injection or nasal drip, leading to nasopharyngeal colonization, acute severe pathological injury, and typical HFMD symptoms. Notably, the nasal drip group exhibited a longer viral excretion cycle and more severe pathological damage. In the subsequent study, rhesus monkeys infected with CVB3 through nasal drips also presented signs of HFMD symptoms, viral excretion, serum antibody conversion, viral nucleic acids and antigens, and the specific organ damages, particularly in the heart. Surprisingly, there were no significant differences in myocardial enzyme levels, and the clinical symptoms resembled those often associated with common, mild infections. In summary, the study successfully developed severe Syrian hamsters and mild rhesus monkey models for CVB3-induced HFMD. These models could serve as a basis for understanding the disease pathogenesis, conducting pre-trial prevention and evaluation, and implementing post-exposure intervention.

Zinc hybrid polyester barrier membrane accelerates guided tissue regeneration.

Barrier membranes play a pivotal role in the success of guided periodontal tissue regeneration. The biodegradable barriers predominantly used in clinical practice often lack sufficient barrier strength, antibacterial properties, and bioactivity, frequently leading to suboptimal regeneration outcomes. Although with advantages in mechanical strength, biodegradability and plasticity, bioinert aliphatic polyesters as barrier materials are usually polymerized via toxic catalysts, hard to be functionalized and lack of antibacterial properties. To address these challenges, we propose a new concept that controlled release of bioactive substance on the whole degradation course can give a bioinert aliphatic polyester bioactivity. Thus, a Zn-based catalytic system for polycondensation of dicarboxylic acids and diols is created to prepare zinc covalent hybrid polyester (PBS/ZnO). The atomically-dispersed Zn2+ ions entering main chain of polyester molecules endow PBS/ZnO barrier with antibacterial properties, barrier strength, excellent biocompatibility and histocompatibility. Further studies reveal that relying on long-term controlled release of Zn2+ ions, the PBS/ZnO membrane greatly expedites osteogenetic effect in guided tissue regeneration (GTR) by enhancing the mitochondrial function of macrophages to induce M2 polarization. These findings show a novel preparation strategy of bioactive polyester biomaterials based on long term controlled release of bioactive substance that integrates catalysis, material structures and function customization.

Internal adaptation and mechanical properties of CAD/CAM glass fiber post-cores in molars: An in vitro study.

OBJECTIVE: The purpose of this in vitro study was to evaluate the internal adaptation, fracture resistance, and fracture pattern of the residual roots and crowns of molars restored with computer-aided design/computer-aided manufacturing (CAD/CAM) glass fiber post-cores, and compare them with three other post-core restorations. MATERIALS AND METHODS: We selected 32 extracted maxillary first molars and divided them into four groups according to the post-core system: traditional casting titanium (Ti) post-cores (TC group); Ti post-cores fabricated with selective laser melting (SLM group); CAD/CAM glass fiber post-cores of the split type (CCS group); and prefabricated glass fiber posts and composite resin cores (PF group). The internal adaptation was analyzed with microcomputed tomography. Teeth were restored with monolithic zirconia crowns and subjected to thermocycling and cyclic loading. A load was applied consistently along the long axis of the tooth until fracture to record the fracture resistance and pattern. For the statistical analysis, one- and two-way analyses of variance, Tukey's post hoc and chi-square tests were performed to compare the differences among the groups. RESULTS: The CCS, TC, and SLM groups exhibited similar internal adaptations across all sections (P < 0.05). The FP group showed good fit with the root canals in the apical and middle sections but a poor fit with those in the cervical section. The fracture resistance was higher in the CCS, TC, and SLM groups compared to the PF group (P < 0.05). The proportions of restorable fractures in the CCS and PF groups were 62.5% and 50%, respectively. Unrestorable fractures were more frequent in the TC and SLM groups at frequencies of 100% and 87.5%, respectively. CONCLUSION: The internal adaptation and fracture resistance of the CCS group were similar to those of the TC and SLM groups, and the fracture pattern was mostly restorable, thus meeting the clinical requirements for molar post-core restorations. CLINICAL SIGNIFICANCE: CCS can be used to restore residual roots and crowns of molars and exhibit high efficacy in terms of adaptability and mechanical properties. More studies are required to evaluate the effectiveness of CCS.