An injectable hydrogel based on Bi2Se3 nanosheets and hyaluronic acid for chemo-photothermal synergistic therapy.

To resolve poor accumulation caused by systemic administration, injectable and responsive hydrogels are the prospective drug delivery systems for localized tumor treatment, owning to negligible invasiveness and accurate administration. Herein, an injectable hydrogel, based on dopamine (DA) crosslinked hyaluronic acid and Bi2Se3 nanosheets (NSs) loading with doxorubicin (DOX) coated with polydopamine (Bi2Se3-DOX@PDA), was developed for synergistic chem-photothermal cancer therapy. The ultrathin functional Bi2Se3-DOX@PDA NSs could be responsive to the weak acidic condition and photothermal effect under NIR laser irradiation, achieving controlled release of DOX. Moreover, nanocomposite hydrogel based on hyaluronic acid matrix could be precisely administrated through intratumoral injection since its injectability and self-healing capacity, remaining at injected sites for at least 12 days. Furthermore, the excellent therapeutics effect of Bi2Se3-DOX@PDA nanocomposite hydrogel was demonstrated on 4 T1 xenograft tumor with outstanding injectability and negligible systemic side-effect. In short, the construction of Bi2Se3-DOX@PDA nanocomposite hydrogel paves a prospective path for local treatment of cancers.

Charge-reversal nanomedicine based on black phosphorus for the development of A Novel photothermal therapy of oral cancer.

Driven by the lifestyle habits of modern people, such as excessive smoking, drinking, and chewing betel nut and other cancer-causing foods, the incidence of oral cancer has increased sharply and has a trend of becoming younger. Given the current mainstream treatment means of surgical resection will cause serious damage to many oral organs, so that patients lose the ability to chew, speak, and so on, it is urgent to develop new oral cancer treatment methods. Based on the strong killing effect of photothermal therapy on exposed superficial tumors, we developed a pH-responsive charge reversal nanomedicine system for oral cancer which is a kind of classic superficial tumor. With excellent photothermal properties of polydopamine (PDA) modified black phosphorus nanosheets (BP NSs) as basal material, then used polyacrylamide hydrochloride-dimethylmaleic acid (PAH-DMMA) charge reversal system for further surface modification, which can be negatively charged at blood circulation, and become a positive surface charge in the tumor site weakly acidic conditions due to the breaking of dimethylmaleic amide. Therefore, the uptake of oral cancer cells was enhanced and the therapeutic effect was improved. It can be proved that this nanomedicine has excellent photothermal properties and tumor enrichment ability, as well as a good killing effect on oral cancer cells through in vitro cytotoxicity test and in vivo photothermal test, which may become a very promising new model of oral cancer treatment.

Versatile Polydopamine Platforms: Synthesis and Promising Applications for Surface Modification and Advanced Nanomedicine.

As a mussel-inspired material, polydopamine (PDA), possesses many properties, such as a simple preparation process, good biocompatibility, strong adhesive property, easy functionalization, outstanding photothermal conversion efficiency, and strong quenching effect. PDA has attracted increasingly considerable attention because it provides a simple and versatile approach to functionalize material surfaces for obtaining a variety of multifunctional nanomaterials. In this review, recent significant research developments of PDA including its synthesis and polymerization mechanism, physicochemical properties, different nano/microstructures, and diverse applications are summarized and discussed. For the sections of its applications in surface modification and biomedicine, we mainly highlight the achievements in the past few years (2016-2019). The remaining challenges and future perspectives of PDA-based nanoplatforms are discussed rationally at the end. This timely and overall review should be desirable for a wide range of scientists and facilitate further development of surface coating methods and the production of PDA-based materials.

[Effect of different surface managements on micro-tensile bond strength of non -carious sclerotic dentin to resin].

PURPOSE: To evaluate the micro-tensile bond strength of 3 different surface managements to non-carious sclerotic dentin. METHODS: Fifteen periodontal patients' occlusal wearing molars which were above 3rd degree were selected. The teeth were equally cut into two pieces along the buccolingual direction, and each piece was randomly divided into 3 groups. Group 1 was processed with polishing, group 2 was processed with EX-26 diamond bur and group 3 was processed with 5# round bur. All teeth were subjected to Optibond treatment, and then filled with composite resin (Premisa) and saved in normal artificial saliva (37 degrees centigrade) for 24 hours. At last, fatigue test pieces were made, the micro-tensile bond strength was evaluated and every specimen was examined under stero-microscope. The micro-tensile bond strength was analyzed with one-way analysis of variance using SPSS17.0 software package. RESULTS: The micro-tensile bond strength of the 3 groups were (10.48±1.29) MPa, (21.52±0.97) MPa and(16.30±1.02) MPa, respectively. The bond strength of EX-26 diamond bur group was significantly greater than that of the other 2 groups (P<0.05). The bond strength of 5# round bur group was significantly greater than that of polishing group (P<0.05). The breakage mostly happened in adhesive dentine surface. CONCLUSIONS: Non-carious sclerotic dentin which is processed with diamond bur has better micro-tensile bonding strength.

[Effects of Nd:YAG laser on micro-tensile bond strength of single bond adhesive system for non-carious sclerotic dentin].

OBJECTIVE: To investigate the effect of Nd:YAG laser on microtensile bond strength of single bond adhesive system for non-carious sclerotic dentin. METHODS: Ten human molars with occlusal wearing were cut into equal halves (nearly 12 mm(2)), and randomly divided into experimental group and control group. The teeth in experimental group were processed with Nd:YAG laser (1 W, 10 Hz), and then applied with Scotchbond and filled with Z350 resin. In control group, the teeth were processed with single bond and filled with Z350 resin. The specimens were sectioned, and the microtensile bond strengths of each sample was tested by a universal testing machine. RESULTS: The bond strength of the experimental group [(26.11 ± 1.62) MPa] was significantly higher than that of the control group [(22.27 ± 2.16) MPa], P < 0.05. Stero-microscope examination indicated that most of the fractures occurred in dentin-resin interface. CONCLUSIONS: Nd:YAG laser can increase the microtensile bond strength of single bond adhesive system in non-carious sclerotic dentin.

[Nd:YAG laser influence on micro-tensile bond strength of different bonding systems to non-carious sclerotic dentin].

PURPOSE: To investigate the influence of Nd:YAG laser on micro-tensile bond strength of different adhesive systems to non-carious sclerotic dentin. METHODS: Fifteen human occlusal wearing molars which were above degree three were selected and cut into nearly equal halves,divided into A(A1,A2),B(B1,B2) and C(C1,C2) three groups at randomly. Then the teeth were processed with Nd:YAG laser(1W, 10Hz),teeth in A2 and C1 were combined with Scotchbond, A1 and B1 were combined with Adper Prompt L-Pop,and B2 and C2 were combined with Clearfil SE Bond, filling with composite resin(Z350) and saving in normal saline (37 degrees centigrade) for 24 hours.Then fatigue test pieces were made, the micro-tensile bond strength was evaluated and every specimen was examined under stero- microscope.The micro-tensile bond strength was performed using one-way analysis of variance using SPSS13.0 software package. RESULTS: The micro-tensile bond strength of the three groups were Scotchbond (22.96 + or - 4.93)MPa, Adper Prompt L-Pop(18.73 + or - 4.71)MPa, Clearfil SE Bond(19.81 + or - 5.36)MPa. The bond strength of Scotchbond compared with the other two bonding systems was statistically significant.The breakage mostly happened in adhesive dentine surface. CONCLUSION: Non-carious sclerotic dentin which is processed with Nd:YAG laser associated with Scotchbond has better bonding strength.

[Study of signal transduction pathway in the expression of inflammatory factors stimulated by lipopolysaccharides from Porphyromonas endodontalis in osteoblasts].

OBJECTIVE: To quantify the interleukin (IL)-1beta mRNA and IL-6 mRNA expression induced by lipopolysaccharides ([PS) extracted from Porphyromonoas endodontalis (P. endodontalis) in osteoblasts, and to relate P. endodontalis LPS to the bone resorptive pathogenesis in the lesions of chronic apical periodontitis. METHODS: MG63 cells was pretreated with PD98059 or SB203580 for 1 h and then treated with P. endodontolis LPS for 6 h. The expression of IL-1beta mRNA and IL-6 mRNA were detected by reverse transcription polymerase chain reaction (RT-PCR) technique. RESULTS: The production of IL-1beta mRNA induced by P. endodontalis LPS decreased in osteoblasts pretreated with PD98059. Both of the production of IL-1beta mRNA and JL-6 mRNA induced by P. endodontalis LPS decreased in osteoblasts pretreated with SB203580. CONCLUSION: The synthesis of IL-1beta mRNA stimulated by Pendodontalis LPS in MG63 probably occur via extracellular signal-regulated kinase (ERK) 1/2 and p38 mitogen activated protein kinase (MAPK) signal transduction system. The synthesis of IL-6 mRNA stimulated by P.endodontalis LPS in MG63 probahly occur via p38MAPK signal transduction system.

[Effect of pulse Nd:YAG laser on micro-tensile bond strength of non-carious sclerotic dentin to resin].

PURPOSE: To evaluate the microtensile bond strength of pulse Nd:YAG laser to non-carious sclerotic dentin. METHODS: Ten extracted human teeth with dental attrition on occlusal surface were cut into nearly equal halves(about 12 mm(2)),and randomly divided into two groups with 10 in each group.All teeth were bonded using an all-in-one self-etch dentin adhesive(Adper Prompt L-Pop) to composite resin after the teeth in the experimental group were processed with pulse Nd:YAG laser(1 W,10 Hz). After 24 hours,under copious water spray the teeth were sectioned into 0.8 mm x 0.8 mm columns with silicon carbide dish at low speed. The microtensile bond strengths of samples were measured.Each fractured specimen was examined under stero-microscope. Paired t test was used for analysis of the microtensile bond strengths between the two groups with SPSS13.0 software package. RESULTS: The microtensile bond strength in the experimental group and control group was (18.94+/-6.81)MPa and (15.76+/-5.61)MPa, respectively, the difference of these two groups was statistically significant(P<0.05). The fractured adhesive dentin surface was mainly adhesive failure mode. CONCLUSION: Pulse Nd:YAG laser(1 W,10 Hz) can improve the strength of composite resin bonding to sclerotic dentin.