New insights into nanotherapeutics for periodontitis: a triple concerto of antimicrobial activity, immunomodulation and periodontium regeneration.

Periodontitis is a chronic inflammatory disease caused by the local microbiome and the host immune response, resulting in periodontal structure damage and even tooth loss. Scaling and root planning combined with antibiotics are the conventional means of nonsurgical treatment of periodontitis, but they are insufficient to fully heal periodontitis due to intractable bacterial attachment and drug resistance. Novel and effective therapeutic options in clinical drug therapy remain scarce. Nanotherapeutics achieve stable cell targeting, oral retention and smart release by great flexibility in changing the chemical composition or physical characteristics of nanoparticles. Meanwhile, the protectiveness and high surface area to volume ratio of nanoparticles enable high drug loading, ensuring a remarkable therapeutic efficacy. Currently, the combination of advanced nanoparticles and novel therapeutic strategies is the most active research area in periodontitis treatment. In this review, we first introduce the pathogenesis of periodontitis, and then summarize the state-of-the-art nanotherapeutic strategies based on the triple concerto of antibacterial activity, immunomodulation and periodontium regeneration, particularly focusing on the therapeutic mechanism and ingenious design of nanomedicines. Finally, the challenges and prospects of nano therapy for periodontitis are discussed from the perspective of current treatment problems and future development trends.

Microemulsion-thermosensitive gel composites as in situ-forming drug reservoir for periodontitis tissue repair through alveolar bone and collagen regeneration strategy.

A satisfactory clinical effect in treating periodontitis is often difficult to achieve by conventional non-surgical systemic drug delivery due to the narrow anatomical structure of the periodontal pocket and insufficient drug concentration at lesion sites. In addition, the feasibility of combating periodontal tissue lesions by restoring the alveolar bone and allowing collagen regeneration has not been fully explored. The objective of this study was to prepare a microemulsion integrating the anti-inflammatory and osteogenic active ingredients of baicalin and clove oil (BC-MEs). Then, the composite hydrogel obtained by mixing poloxamer 407 and 188 was used as the thermosensitive gel matrix to load BC-MEs and form a drug reservoir (Gel-BC-MEs) injectable in situ. Gel-BC-MEs exhibited a significant, sustained release of baicalin for 12 h, gelation temperature was 33.4 ± 0.36 °C, and pH was 5.45 ± 0.12. The experiment on a rat periodontitis model demonstrated that Gel-BC-MEs significantly improved periodontal tissue repair by collagen regeneration and osteogenesis by inhibiting osteoclast infiltration. This study proposes a novel strategy for periodontal tissue repair by enhancing the therapeutic potential of a microemulsion using an in situ nano-gel delivery system.

Sorafenib-Loaded PLGA-TPGS Nanosystems Enhance Hepatocellular Carcinoma Therapy Through Reversing P-Glycoprotein-Mediated Multidrug Resistance.

Multidrug resistance (MDR) is a key determinant for hepatocellular carcinoma chemotherapy failure. P-glycoprotein is one of the main causes of MDR by causing drug efflux in tumor cells. In order to solve this thorny problem, we prepared a sorafenib-loaded polylactic acid-glycolic acid (PLGA) - D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) nanoparticles (SPTNs). SPTNs were successfully synthesized through an ultrasonic emulsion solvent evaporation method with a favourable encapsulation efficiency of 90.35%. SPTNs were almost spherical in shape with uniform particle size (215.70 ± 0.36 nm), narrow polydispersity index (0.27 ± 0.02) and negative surface charge (-26.01 ± 0.65 mV). In the cellular uptake assay, the intracellular coumarin-6 (C6) fluorescence of TPGS component-based PLGA nanoparticles (C6-PTNs) was 1.63-fold higher relative to that of PVA component-based PLGA nanoparticles (C6-PVNs). The half-maximal inhibitory concentration and apoptosis ratio of SPTNs against HepG2/MDR cells were 3.90 µM and 75.62%, respectively, which were notably higher than free SF and sorafenib-PLGA-PVA nanoparticles (SPVNs). The anti-drug efflux activities of SPTNs were assessed by the intracellular trafficking assay using verapamil as a P-gp inhibitor. SPTNs could effectively inhibit the drug efflux in tumor cells detected by flow cytometry, and suppressed relative MDR1 gene as well as P-glycoprotein expression in tumor cells. Attributed to the MDR reversion effect of SPTNs, the in vivo antitumor efficacy experiment showed that SPTNs significantly inhibited the tumor growth of HepG2/MDR xenograft-bearing nude mice, and obviously reduced the toxicity against liver and kidney compared with SF treatment. In summary, SPTNs, as highly efficient and safe antitumor nano delivery systems, showed promising potential for hepatocellular carcinoma therapy through reversing P-glycoprotein-mediated MDR. Graphical Abstract.

Pueraria flavones-loaded bile salt liposomes with improved intestinal absorption and oral bioavailability: in vitro and in vivo evaluation.

Pueraria flavone (PF), the main component of Pueraria lobata, is a traditional Chinese medicine used for the treatment of cardiovascular and cerebrovascular diseases; however, it exhibits low oral bioavailability because of its poor membrane permeability. In this study, PF-loaded sodium deoxycholate-decorated liposomes (SDC-Lips) were prepared using the reverse-phase evaporation method and optimised using the Box-Behnken design method. The morphology, particle size, zeta potential, and entrapment efficiency of these PF-loaded SDC-Lips were evaluated. The release behaviours of PF-loaded SDC-Lips in simulated gastric and intestinal fluids were consistent with the Weibull kinetic model. In situ intestinal perfusion studies showed that the absorption characteristics of free PF in rats were mainly passive diffusion and partly active transport, and the duodenum was the main absorption site. After encapsulated with SDC-Lips, the absorption of PF increased significantly. The in vivo pharmacokinetic parameters of area under the plasma concentration-time curve (AUC)(0 → 12 h) and AUC(0 → ∞) of PF-loaded SDC-Lips after intragastric administration were 1.34-fold and 1.543-fold, respectively. Overall, the PF-loaded SDC-Lips improved the oral absorption of PF by increasing its solubility and might be considered a promising formulation strategy for prolonging the biological activity time of PF.

Sp1 promotes dental pulp stem cell osteoblastic differentiation through regulating noggin.

Based on the high self-renewal ability and osteoblastic differentiation capacity, dental pulp stem cells (DPSCs) are suggested to be promising cell source for osteogenesis. Therefore, illustrating the mechanism of osteoblastic differentiation of DPSCs is required. This current study aims to illustrate the role and mechanism of Sp1 in regulating osteoblastic differentiation of DPSCs. In this study, we downregulated Sp1 in DPSCs and evaluated the osteoblastic differentiation by measuring Runx2 and OCN expression with Western blot analysis and by Alizarin red staining. Furthermore, we investigated the mechanism of Sp1 regulating noggin with Firefly luciferase reporter gene assay and ChIP assay, and correspondingly evaluated the function of noggin in Sp1-regulated osteoblastic differentiation of DPSCs. We found that knockdown of Sp1 inhibits the expression of ALP, Runx2, COL1A1 and OCN, and decreases ALP staining, Alizarin red staining. Sp1 binds to noggin promoter and inhibits noggin expression, thus correspondingly regulates DPSCs osteoblastic differentiation. In conclusion, our study revealed that Sp1 regulates DPSCs osteoblastic differentiation through noggin and that Sp1/noggin can provide new perspective for enhancing DPSCs osteogenesis.

Safety and efficacy of transpupillary silicone oil removal in combination with micro-incision phacoemulsification cataract surgery: comparison with 23-gauge approach.

BACKGROUND: To evaluate safety and efficacy of transpupillary silicone oil removal combined with micro-incision phacoemulsification cataract surgery, and to compare results of transpupillary with 23-gauge three-port vitrectomy approach. METHODS: Consecutive cases that underwent silicone oil removal using either transpupillary or three-port approach in combination with micro-incision phacoemulsification cataract surgery were retrospectively reviewed. The main outcome measures were postoperative detachment rate, silicone oil residuals, best corrected visual acuity (BCVA) and intraocular pressure (IOP). RESULTS: A total of 64 cases were included, 19 in transpupillary and 45 in three-port. Postoperative detachment rate within 3 months in transpupillary versus three-port was 15.8% versus 4.4% (p = 0.14), Silicone oil residuals was 7.4 ± 3.2% versus 7.1 ± 2.8% (transpupillary vs. three-port, p = 0.71). Preoperative versus postoperative BCVA (logMAR) was 1.49 ± 0.61 versus 1.42 ± 0.61 in transpupillary approach (p = 0.28) and 1.53 ± 0.48 versus 1.45 ± 0.57 in three-port approach (p = 0.11). Transpupillary approach resulted in lower IOP at postoperative day 2 (12.2 ± 2.3 mmHg vs. 13.5 ± 2.2 mmHg, p < 0.05), while postoperative follow-up at 1 month revealed no significant difference (p = 0.21). CONCLUSIONS: Transpupillary silicone oil removal combined with micro-incision phacoemulsification cataract surgery is less invasive and can be an alternative in some circumstances.

Development and Evaluation of Minocycline Hydrochloride-Loaded In Situ Cubic Liquid Crystal for Intra-Periodontal Pocket Administration.

In the present study, an injectable in situ liquid crystal formulation was developed for local delivery of minocycline hydrochloride (MH) for chronic periodontitis treatment. The physicochemical properties, phase structures, in vitro drug release and pharmacodynamics of in situ liquid crystals were investigated. The optimal formulation (phytantriol (PT)/propylene glycol (PG)/water, 63/27/10, w/w/w) loaded with 20 mg/g MH was proved to be injectable. The precursor formulation can form a cubic phase gel in excess water in 6.97 ± 0.10 s. The results of in vitro drug release suggested the MH presented a sustained release for 4 days. Liquid crystal precursor formulation significantly reduced gingival index, probing depth and alveolar bone loss compared to the model group (p < 0.01). Besides, the pathological characteristics of model rats were improved. The results suggested that MH-loaded in situ cubic liquid crystal possessed of sustained release ability and periodontal clinical symptoms improvement. The developed in situ cubic liquid crystal may be a potentially carrier in the local delivery of MH for periodontal diseases.

An injectable in situ hexagonal mesophase system for local delivery of minocycline hydrochloride: Preparation and pharmacodynamics in rats.

In this study, an optimized in situ reversed hexagonal mesophase loaded with minocycline hydrochloride (MH) was developed for the chronic periodontitis treatment. The in situ hexagonal liquid crystals (ISH2) comprised phytantriol (PT), propylene glycol (PG), water and vitamin E acetate (VitEA). The physicochemical properties, in vitro drug release and the therapeutic effects on chronic periodontitis of the formed samples were tested. The injectable liquid crystal-forming systems were characterized by crossed-polarized light microscopy, small angle X-ray scattering, and rheological measurements. The optimal ISH2 (PT/PG/water/VitEA, 56:27:10:7, w/w/w/w) loaded with 20 mg·g-1 MH was proved to be injectable with suitable pH, and was able to sustain the drug release for 10 days. The pharmacodynamic studies of the optimal formula were performed on male SPF rats, the Periocline® ointment was used as a control. The investigated ISH2 loaded with MH was demonstrated to be effective for periodontal treatment with significantly improved gingival index, pocket depth and alveolar bone loss. The developed ISH2 may be a promising application for local delivery system of MH in treating periodontal diseases.

[Novel liposomal drug delivery system actively targeting Cryptococcus neoformans and elimination of infection].

The purpose of this study is to develop a liposomal drug delivery system actively targeting Cryptococcus neoformans and explore its feasibility in therapy of cryptococcal infection. The specific fungi-binding peptide was screened from 12-mer random phage display library, and linked to PEG-DSPE as the functional material of liposomes. The targeting capability of peptide-modified liposomes were investigated by fungi binding assay in vitro and fluorescence imaging in vivo. Itraconazole as a model drug were then encapsulated in the liposomes and were evaluated in pharmacodynamic test in vitro and for therapeutic effects against cryptococcal meningitis complicated with pulmonary cryptococcosis in vivo. The results showed that the peptide (sequence: NNHREPPDHRTS) could selectively recognize Cryptococcus and effectively mediate the corresponding liposomal formulation to accumulate in the infection site in vivo. This peptide-modified liposome has a small particle size (mean diameter of 88.25 ± 2.43 nm) with a homogeneous distribution and high encapsulation efficiency (88.05 ± 0.25 %) of itraconazole. After intravenous administration, the pathogens were obviously eliminated in lung and brain, and the life-span of model mice were significantly prolonged, suggesting a promising potential of this cryptococcosis targeting strategy.

[Correlation between Constitution of Yin Deficiency Syndrome and Polymorphism of HLA-DQA1/Treatment Response of Peg-IFNalpha Therapy in HBeAg Positive Chronic Hepatitis B Patients].

OBJECTIVE: To observe the correlation between constitution of yin deficiency syndrome (YDS) and polymorphism of HLA-DQA1/treatment response of Peg-lFNalpha therapy in HBeAg positive chronic hepatitis B (CHB) patients, and to explore constitution of Chinese medicine (CM) in response of interferon therapy. METHODS: Totally 120 HBeAg positive CHB patients who were treated with Peg-IFNalpha were enrolled, and assigned to YDS group (59 cases) and non-YDS group (61 cases) according to classification of CM constitutions. All patients were subcutaneously injected with Peg-IFNalpha-2b (1.0 microg/kg body weight) or Peg-IFNalpha-2a (180 microg), once per week. Effective efficacy was primarily judged when complete response (CR) or partial response (PR) was obtained at month 6. Those with CR or PR completed 1 year therapeutic course. HLA-DQA1 gene types were detected by polymerase chain reaction sequence specific primers (PCR-SSP). The distribution difference of CM constitutions in patients with CR or PR and their inter-group HLA-DQA1 allele frequency were compared. RESULTS: Different treatment responses of Peg-IFNalpha were observed in CHB patients of two different CM constitutions. The ratio of CR + PR was 61.0% (36/59) in YDS group, obviously lower than that in NYDS group [78.7% (48/61), P < 0. 05]. Patients with CR had a lower allele frequency of HLA-DQA1 * 0501 than those with no-response [14.8% (8/54) vs. 30.6% (22/72)] with statistical difference (P < 0.05). Patients with CR had a higher allele frequency of HLA-DQA1 * 0601 than those with no-response [18.5% (10/54) vs. 5.6% (4/72)] with statistical difference (P < 0.05). The allele frequency of HLA-DQA1 * 0301 was lower in YDS group than in non-YDS group [2. 5% (3/118) vs. 9.8% (12/122)] with statistical difference (P < 0.05). The allele frequency of HLA-DQA1 * 0501 was higher in YDS group than in non-YDS group [33.9% (40/118) vs. 18.9% (23/122)] with statistical difference (P < 0.05). Yet statistical significance was lost after adjustment (Pc > 0.05 for both). CONCLUSIONS: Both constitutions of CM and HLA-DQA1 gene polymorphism af- fect HBeAg positive CHB patients' response to Peg-INFalpha. Constitutions of YDS and HLA-DQA1 * 0501 was not favorable to response, their association needed to be further studied.

Treatment of oilfield fracturing wastewater by a sequential combination of flocculation, Fenton oxidation and SBR process.

In this study, a combined process was developed that included flocculation, Fenton oxidation and sequencing batch reactor (SBR) to treat oilfield fracturing wastewater (FW). Flocculation and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance biodegradability, respectively. For flocculation, the optimum conditions were: polymeric aluminium chloride dosage, 40 mg/L; polyacrylamide dosage, 4 mg/L; dilution ratio, 1:2 and stirring time, 30 min. For Fenton oxidation, a total reaction time of 60 min, a H2O2dosage of 2 m mol/L, with a [H2O2]/[FeSO4] ratio of 2 were selected to achieve optimum oxidation. Under these optimum flocculation and Fenton oxidation conditions, the COD removal efficiency was found to be 76.6%. Following pretreatment with flocculation and Fenton oxidation, the FW was further remediated using a SBR. Results show that COD was reduced to 92 mg/L, and the overall water quality of the final effluent could meet the class I national wastewater discharge standard of petrochemical industry of China.

Flavonoid extract from propolis alleviates periodontitis by boosting periodontium regeneration and inflammation resolution via regulating TLR4/MyD88/NF-κB and RANK/NF-κB pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Chinese medicine, propolis has been used for treating oral diseases for centuries, widely. Flavonoid extract is the main active ingredient in propolis, which has attracted extensive attention in recent years. AIM OF THE STUDY: The objective and novelty of the current study aims to identify the mechanism of total flavonoid extract of propolis (TFP) for the treatment of periodontitis, and evaluate the therapeutic effect of TFP-loaded liquid crystal hydrogel (TFP-LLC) in rats with periodontitis. METHODS: In this study, we used lipopolysaccharide-stimulated periodontal ligament stem cells (PDLSCs) to construct in vitro inflammation model, and investigated the anti-inflammatory effect of TFP by expression levels of inflammatory factors. Osteogenic differentiation was assessed using alkaline phosphatase activity and alizarin red staining. Meanwhile, the expression of toll like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), nuclear factor-kappa B (NF-κB), receptor activator of NF-κB (RANK) etc, were quantitated to investigate the therapeutic mechanism of TFP. Finally, we constructed TFP-LLC using a self-emulsification method and administered it to rats with periodontitis via periodontal pocket injection to evaluate the therapeutic effects. The therapeutic index, microcomputed tomography (Micro-CT), H&E staining, TRAP staining, and Masson staining were used for this evaluation. RESULTS: TFP reduced the expression of TLR4, MyD88, NF-κB and inflammatory factor in lipopolysaccharide-stimulated PDLSCs. Meanwhile, TFP simultaneously regulating alkaline phosphatase, RANK, runt-associated transcription factor-2 and matrix metalloproteinase production to accelerate osteogenic differentiation and collagen secretion. In addition, TFP-LLC can stably anchor to the periodontal lesion site and sustainably release TFP. After four weeks of treatment with TFP-LLC, we observed a decrease in the levels of NF-κB and interleukin-1ß (IL-1ß) in the periodontal tissues of rats, as well as a significant reduction in inflammation in HE staining. Similarly, Micro CT results showed that TFP-LLC could significantly inhibit alveolar bone resorption, increase bone mineral density (BMD) and reduce trabecular bone space (Tb.Sp) in rats with periodontitis. CONCLUSION: Collectively, we have firstly verified the therapeutic effects and mechanisms of TFP in PDLSCs for periodontitis treatment. Our results indicate that TFP perform anti-inflammatory and tissue repair activities through TLR4/MyD88/NF-κB and RANK/NF-κB pathways in PDLSCs. Meanwhile, for the first time, we employed LLC delivery system to load TFP for periodontitis treatment. The results showed that TFP-LLC could be effectively retained in the periodontal pocket and exerted a crucial role in inflammation resolution and periodontal tissue regeneration.

Active targeting microemulsion-based thermosensitive hydrogel against periodontitis by reconstructing Th17/Treg homeostasis via regulating ROS-macrophages polarization cascade.

Periodontitis is a multifactorial inflammatory disease characterized by severe alveolar bone damage and attachment loss. The imbalance of T help 17 (Th17) / regulatory T cells (Treg) induces excessive interleukin (IL)-17, which leads to alveolar bone damage and aggravates the development of periodontitis. Therefore, we proposed a therapeutic strategy to restore Th17/Treg homeostasis by interfering reactive oxygen species (ROS)-macrophage polarization cascade using active targeting microemulsions-based thermosensitive hydrogel. Folic acid-modified quercetin-loaded microemulsions (FA-Qu-MEs) were dispersed in poloxamer 407 and poly(N-isopropylacrylamide) matrix of hydrogel (FA-Qu-MEs@Gel). FA-Qu-MEs@Gel could be locally injected into the periodontal pocket and sustainedly release drugs. FA-Qu-MEs exhibited excellent ROS scavenging potency by targeting macrophages, resulting M1 phenotype macrophage from to M2 phenotype macrophage. Subsequently, the phenotypic changes of macrophages lead to decreased expression of IL-6 and tumor necrosis factor-α, which inhibited activated Th17, while IL-10 secreted by M2 macrophages promoted Treg differentiation. Finally, the restored Th17/Treg homeostasis reduced the level of IL-17 to accelerate alveolar bone regeneration. This study deigns a novel system that promote alveolar bone regeneration by remodeling Th17/Treg homeostasis via regulating ROS-macrophages polarization cascade for periodontitis treatment.

Directional migration of vascular smooth muscle cells guided by a molecule weight gradient of poly(2-hydroxyethyl methacrylate) brushes.

Directional migration of cells mediated by gradient cues in vitro can mimic the corresponding biological events in vivo and thereby provides a way to disclose the cascade responses in tissue regeneration processes and to develop novel criteria for design of tissue-inductive biomaterials. In this work, a molecular weight gradient of poly(2-hydroxyethyl methacrylate) (PHEMA) brushes with a thickness ranging from 3 to 30 nm and slopes of 0.8-3.2 nm/mm were fabricated by using surface-initiated atom transfer radical polymerization (ATRP) and a dynamically controlled reaction process. The PHEMA gradients were characterized by X-ray photoelectron spectrometry (XPS) and ellipsometry. The adhesion number, spreading area, adhesion force, and expression of focal adhesion and actin fibers of vascular smooth muscle cells (VSMCs) decreased along with the increase of the PHEMA brushes length. The VSMCs exhibited preferential orientation and enhanced directional migration toward the direction of reduced PHEMA thickness, whose extent was dependent on the gradient slope and polymer thickness. Most of the cells were oriented, and 87% of the cells moved directionally at the optimal conditions.

Foot-and-mouth disease virus-like particles produced by a SUMO fusion protein system in Escherichia coli induce potent protective immune responses in guinea pigs, swine and cattle.

Foot-and-mouth disease virus (FMDV) causes a highly contagious infection in cloven-hoofed animals. The format of FMD virus-like particles (VLP) as a non-replicating particulate vaccine candidate is a promising alternative to conventional inactivated FMDV vaccines. In this study, we explored a prokaryotic system to express and assemble the FMD VLP and validated the potential of VLP as an FMDV vaccine candidate. VLP composed entirely of FMDV (Asia1/Jiangsu/China/2005) capsid proteins (VP0, VP1 and VP3) were simultaneously produced as SUMO fusion proteins by an improved SUMO fusion protein system in E. coli. Proteolytic removal of the SUMO moiety from the fusion proteins resulted in the assembly of VLP with size and shape resembling the authentic FMDV. Immunization of guinea pigs, swine and cattle with FMD VLP by intramuscular inoculation stimulated the FMDV-specific antibody response, neutralizing antibody response, T-cell proliferation response and secretion of cytokine IFN-γ. In addition, immunization with one dose of the VLP resulted in complete protection of these animals from homologous FMDV challenge. The 50% protection dose (PD50) of FMD VLP in cattle is up to 6.34. These results suggest that FMD VLP expressed in E. coli are an effective vaccine in guinea pigs, swine and cattle and support further development of these VLP as a vaccine candidate for protection against FMDV.

5-Hydroxytryptamine levels in the pulmonary arterioles of broilers with induced pulmonary hypertension and its relationship to pulmonary vascular remodelling.

This experiment was performed to explore the relationship between 5-hydroxytryptamine (5-HT) levels in pulmonary arterioles and in pulmonary vascular remodelling in broilers. Pulmonary arterial hypertension was induced by injecting cellulose microparticles intravenously. Pulmonary hypertension syndrome (PHS) morbidity, right ventricle/total ventricle weight ratio (RV/TV), packed cell volume (PCV), haemoglobin concentration (HB), vessel wall area to vessel total area ratio (WA/TA) and mean tunica media thickness in pulmonary arterioles (mMTPA) were measured. Proliferating cell nuclear antigen (PCNA), argyrophilic nucleolar organizer region proteins (Ag-NORs) and 5-HT content in pulmonary arterioles were determined. The results showed that injecting cellulose microparticles intravenously in broilers could successfully increase the PHS morbidity, significantly elevate RV/TV, PCV and HB, significantly increase mMTPA and WA/TA, and significantly increase the argyrophilic particles in smooth muscle cell nucleoli, PCNA-positive cells in the medial layer, and the 5-HT content in pulmonary arterioles. Correlation analysis showed that the level of 5-HT was strongly positively correlated with PCNA and Ag-NORs. The results indicated that the increase of 5-HT in the tunica media could possibly promote the proliferation of smooth muscle cells in pulmonary arterioles and thus the occurrence of pulmonary vascular remodelling.

Influence of lipid composition on the phase transition temperature of liposomes composed of both DPPC and HSPC.

OBJECTIVE: Phase transition of the lipid membrane is one of the most important properties of liposomes. The objective of this study was to investigate the influence of molar ratio of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and hydrogenated soy phosphatidylcholine (HSPC) on the phase transition temperature (T(m)) of the liposomes. MATERIALS AND METHODS: The T(m)s of the liposomes with different phosphatidylcholine (PC) composition were determined by calcein release test and differential scanning calorimetry (DSC). RESULTS: Only one phase transition was observed for liposomes composed of both DPPC and HSPC, indicating that DPPC and HSPC might combine into one phase with single phase transition. The T(m) of the liposomes composed of both DPPC and HSPC was directly dependent on the molar ratio of the two PCs. Moreover, DPPC percentage and T(m) relationship could be fitted with a linear equation (r(2) > 0.98). In addition, the serum stability of the liposomes at 37°C was directly increased with the increase of DPPC percentage. When 10% DSPE-PEG2000 was added, the significant increase of calcein release at T(m) and decrease at 37°C were observed. DISCUSSION: It is easy to obtain liposomes with a T(m) in between that of DPPC and HSPC by modifying the molar ratio of DPPC and HSPC. CONCLUSION: With the modification of T(m), the liposomes containing various ratios of DPPC and HSPC may have promising application potential in the field of thermosensitive liposomes (TSLs). After 10% DSPE-PEG2000 is added, a formulation of sterically stabilized liposomes with the proper thermal sensitivity can be obtained.

Descending necrotizing mediastinitis caused by Streptococcus constellatus: A case report and review of the literature.

RATIONALE: Descending necrotizing mediastinitis (DNM) is a rare but severe mediastinal infection. If not diagnosed and treated promptly, the consequences can be very serious. Here, we shared a successful diagnosis and treatment case of DNM that originates from oral to neck and mediastinum caused by Streptococcus constellatus (S constellatus). S constellatus is a clinically uncommon gram-positive coccus and is known for its ability to form abscesses. Timely surgical drainage and the correct use of antibiotics are key to successful treatment. PATIENT CONCERNS: A 53-year-old male admitted to hospital with painful swelling of the right cheek, persistent oral pus and moderate fever lasting 1 week, followed by rapid development of a mediastinal abscess. DIAGNOSES: He was diagnosed with DNM caused by S constellatus. INTERVENTIONS: On the evening of admission, an emergency tracheotomy and thoracoscopic exploration and drainage of the right mediastinum, floor of the mouth, parapharynx and neck abscess were performed. Antibiotics were administered immediately. OUTCOMES: At 28 days post-operatively, the abscess was absorbed, bilateral lung exudate decreased and the patient temperature, aspartate transaminase, alanine transaminase, bilirubin and platelets returned to normal. The patient was discharged after completing 4 weeks of antibiotic therapy. Follow-up at 3 months after discharge revealed no recurrence of the abscess. LESSONS: Early surgical drainage and antibiotics treatment are important in mediastinal abscesses and infectious shock due to Streptococcus asteroids.

Enhanced removal of Cr(VI) by polyethyleneimine-modified bamboo hydrochar.

Hydrochar is an environmentally friendly and cheap adsorbent, but its adsorption amounts for anions is very limited. The functionalized hydrochar can overcome this shortcoming. Herein, polyethyleneimine-modified hydrochar (PEI-HC) was synthesized from hydrothermal carbonization (HTC) of methyl acrylate and bamboo after addition of initiator ammonium persulfate, and then modified by polyethyleneimine (PEI), which was used to treat Cr(VI). PEI-HC was tested by XANES, EXAFS, SEM-EDS, XPS, FTIR, N2 sorption isotherms, zeta potential, and elemental analyses. The characterizations showed that PEI was successfully grafted onto hydrochar, and the PEI-HC was rich in N and O functional groups, which presented high Cr(VI) sorption ability (528.41 mg·g-1 at pH 2). The bath experiments found the pseudo-second-order kinetic and Freundlich equations can well describe the adsorption kinetics and isotherm of the Cr(VI) adsorption onto PEI-HC, respectively. Electrostatic interaction, reduction, complexation, and H-bonding are the main removal mechanisms as supported by XANES, EXAFS, XPS, and FTIR. This study provides a strategy of combining HTC and free radical graft polymerization to convert agricultural and forestry wastes into functionalized hydrochar, showing highly efficient removal of Cr(VI).

Smart stimuli-responsive hydrogels for drug delivery in periodontitis treatment.

Periodontitis is a chronic inflammatory disease initiated by pathogenic biofilms and host immunity that damages tooth-supporting tissues, including the gingiva, periodontal ligament and alveolar bone. The physiological functions of the oral cavity, such as saliva secretion and chewing, greatly reduce the residence of therapeutic drugs in the area of a periodontal lesion. In addition, complex and diverse pathogenic mechanisms make effectively treating periodontitis difficult. Therefore, designing advanced local drug delivery systems and rational therapeutic strategies are the basis for successful periodontitis treatment. Hydrogels have attracted considerable interest in the field of periodontitis treatment due to their biocompatibility, biodegradability and convenient administration to the periodontal pocket. In recent years, the focus of hydrogel research has shifted to smart stimuli-responsive hydrogels, which can undergo flexible sol-gel transitions in situ and control drug release in response to stimulation by temperature, light, pH, ROS, glucose, or enzymes. In this review, we systematically introduce the development and rational design of emerging smart stimuli-responsive hydrogels for periodontitis treatment. We also discuss the state-of-the-art therapeutic strategies of smart hydrogels based on the pathogenesis of periodontitis. Additionally, the challenges and future research directions of smart hydrogels for periodontitis treatment are discussed from the perspective of developing efficient hydrogel delivery systems and potential clinical applications.