Hybrid Polymer Vesicles: Controllable Preparation and Potential Applications.

Hybrid polymer vesicles contain functional nanoparticles (NPs) in their walls, interfaces, coronae, or cavities. NPs render the hybrid vesicles with specific physical properties, while polymers endow them with structural stability and may significantly reduce the high toxicity of NPs. Therefore, hybrid vesicles integrate fascinating multifunctions from both NPs and polymeric vesicles, which have gained tremendous attention because of their diverse promising applications. Various types of delicate hybrid polymeric vesicles with size control and tunable localization of NPs in different parts of vesicles have been constructed via in situ and ex situ strategies, respectively. Their potential applications have been widely explored, as well. This review presents the progress of block copolymer (BCP) vesicle systems containing different types of NPs including metal NPs, magnetic NPs, and semiconducting quantum dots (QDs), etc. The strategies for controlling the location of NPs within hybrid vesicles are discussed. Typical potential applications of the elegant hybrid vesicles are also highlighted.

Two-stage injection of polymer and microsand during ballasted flocculation for treating kaolin waters with or without humic acid: Floc evolutional characteristics, performance and mechanisms.

Ballasted flocculation is regarded as a most promising water treatment technology in aspects of retrofit and high-rate applications. To deep understand the incorporation behaviors of ballasting agent into ballasted floc growth, two distinct injection modes (namely a two-stage injection of polyacrylamide (PAM) alone, and a two-stage injection of both PAM and microsand) were developed in this study. Then, ballasted flocculation tests of kaolin and kaolin-HA (humic acid) waters were conducted at varying split ratios for fixed total dosages of both PAM and microsand. The experimental results showed that for either two-stage injection mode, the higher the second percentage of each split ratio, the greater the average size of maturated flocs at the second sub-stage of maturation. Meanwhile, the turbidity and UV254 values of settled water became lower at 30 and 180 s of sedimentation, suggesting that varying split ratios significantly affected the kinetics of ballasted floc growth. Moreover, it was suggested that the selection of either two-stage injection mode or corresponding split ratios played a more pronounced role in the HA removal than the total dosage of PAM. This suggestion was supported by SEM, FTIR and XPS analyses for surface morphological details, functional groups and chemical states of maturated flocs eventually formed in the kaolin-HA water through both two-stage injection modes. Accordingly, newly-established conceptual models of ballasted floc growth were proposed to explore the potential influencing mechanisms of varying split ratios on the ballasted flocculation performance. At each sub-stage of maturation, an appropriate dosage ratio between PAM and microsand was of great importance to effectively incorporate microsand particles into ballasted floc formation, besides the hydrolyzed produces of AS coagulant formed at the coagulation stage of ballasted flocculation. This study is expected to provide valuable insights for making ballasted flocculation more effective, economical and sustainable in water treatment engineering.

Enhanced heterogeneous interface to construct intelligent conductive hydrogel gas sensor for individualized treatment of infected wounds.

In this study, we developed an enhanced heterogeneous interface intelligent conductive hydrogel NH3 sensor for individualized treatment of infected wounds. The sensor achieved monitoring, self-diagnosis, and adaptive gear adjustment functions. The PPY@PDA/PANI(3/6) sensor had a minimum NH3 detection concentration of 50 ppb and a response value of 2.94 %. It also had a theoretical detection limit of 49 ppt for infected wound gas. The sensor exhibited a fast response time of 23.2 s and a recovery time of 42.9 s. Tobramycin (TOB) was encapsulated in a self-healing QCS/OD hydrogel formed by quaternized chitosan (QCS) and oxidized dextran (OD), followed by the addition of polydopamine-coated polypyrrole nanowires (PPY@PDA) and polyaniline (PANI) to prepare electrically conductive drug-loaded PPY@PDA/PANI hydrogels. The drug-loaded PPY@PDA/PANI hydrogel was combined with a PANI/PVDF membrane to form an enhanced heterogeneous interfacial PPY@PDA/PANI/PVDF-based sensor, which could adaptively learn the individual wound ammonia response and adjust the speed of drug release from the PPY@PDA/PANI hydrogel with electrical stimulation. Drug release and animal studies demonstrated the efficacy of the PPY@PDA/PANI hydrogel in inhibiting infection and accelerating wound healing. In conclusion, the gas-sensitive conductive hydrogel sensing system is expected to enable intelligent drug delivery and provide personalized treatment for complex wound management.

Nanofiber Composite Microchannel-Containing Injectable Hydrogels for Cartilage Tissue Regeneration.

Articular cartilage tissue is incapable of self-repair and therapies for cartilage defects are still lacking. Injectable hydrogels have drawn much attention in the field of cartilage regeneration. Herein, the novel design of nanofiber composite microchannel-containing hydrogels inspired by the tunnel-piled structure of subway tunnels is proposed. Based on the aldehydized polyethylene glycol/carboxymethyl chitosan (APA/CMCS) hydrogels, thermosensitive gelatin microrods (GMs) are used as a pore-forming agent, and coaxial electrospinning polylactic acid/gelatin fibers (PGFs) loaded with kartogenin (KGN) are used as a reinforcing agent and a drug delivery system to construct the nanofiber composite microchannel-containing injectable hydrogels (APA/CMCS/KGN@PGF/GM hydrogels). The in situ formation, micromorphology and porosity, swelling and degradation, mechanical properties, self-healing behavior, as well as drug release of the nanofiber composite microchannel-containing hydrogels are investigated. The hydrogel exhibits good self-healing ability, and the introduction of PGF nanofibers can significantly improve the mechanical properties. The drug delivery system can realize sustained release of KGN to match the process of cartilage repair. The microchannel structure effectively promotes bone marrow mesenchymal stem cell (BMSC) proliferation and ingrowth within the hydrogels. In vitro and animal experiments indicate that the APA/CMCS/KGN@PGF/GM hydrogels can enhance the chondrogenesis of BMSCs and promote neocartilage formation in the rabbit cartilage defect model.

[In vivo imaging in tumor-bearing animals and pharmacokinetics of PEGylated liposomes modified with RGD cyclopeptide].

The hydroxycamptothecin (HCPT) PEGylated liposomes (HCPT-LP) were modified with RGD cyclopeptide formed the tumor-targeting liposomes (HCPT-RGD-LP). HCPT-LP and HCPT-RGD-LP were injected intravenously with single dose of 5 mg x kg(-1) to rats. The drug concentration in plasma was determined and the pharmacokinetic behaviour was compared. The HCPT distribution in heart, liver, spleen, lung, kidney and plasma of mice was investigated following intravenous administration of HCPT-LP and HCPT injection. The nude mice implanted human hepatoma HepG2 cells were studied by in vivo imaging. The fluorescent probe was DiR and the nude mice were injected with DiR PEGylated liposomes (DiR-LP) and DiR-LP modified with RGD cyclopeptide (DiR-RGD-LP). The results showed that there was no significant difference (P > 0.05) of main pharmacokinetic parameters t1/2beta, CL, V(c), AUC(0-48 h), AUC(0-inifinity), MRT(0-48 h), MRT(0-infinity) between HCPT-RGD-LP and HCPT-LP. HCPT-LP had a remarkably better long-circulating effect than HCPT injection in mice and the concentration of HCPT was highest in liver. The DiR accumulation in tumors of DiR-RGD-LP was higher than that of DiR-LP by the visualized fluorescence of in vivo imaging. It indicated that such PEGylated liposomes modified with RGD cyclopeptide could improve the tumor targeting efficacy.

[Research on the pathogeny of black tooth stain and association between black tooth stain and primary dentition caries in children].

PURPOSE: To investigate the relationship between polymorphism of cytochrome P450, family 2, subfamily A, polypeptide 6(CYP2A6) and periodontitis, the expression of inflammatory cytokines in 123 Han smokers. METHODS: From October 2018 to October 2019, a total of 123 smokers with periodontitis were selected as the experimental group, and 125 non-smokers as the control group. The general data of the patients were collected, including age, gender, body mass index (BMI), chewing and brushing habits, as well as molar condition; plaque index (PLI), gingival bleeding index (BI), periodontal probing depth (PD) and attachment loss (AL) were detected. CYP2A6 was amplified by PCR. The level of interleukin (IL)-17, IL-1, IL-6, IL-23 and tumor necrosis factor-α (TNF-α) in GCF was detected by enzyme-linked immunosorbent assay(ELISA). SPSS 25.0 software package was used for statistical analysis of the data. RESULTS: There was significant difference in gender, PLI, IL-17, IL-1, IL-6, IL-23, TNF-α level in GCF between the two groups(P＜0.05). All samples were amplified by PCR. Among them, 23 were not amplified, which were identified as CYP2A6 deletion type (CYP2A6del), including 5 in the experimental group and 18 in the control group; 225 were amplified and identified as CYP2A6 wild type(CYP2A6wt), including 118 in the experimental group and 107 in the control group. There was significant difference in CYP2A6 genotype between the two groups(P＜0.05). In the experimental group, the level of IL-1 and PLI of different CYP2A6 genotypes was significantly different(P＜0.05); and in the control group, the level of IL-17 and PLI of different CYP2A6 genotypes was also significantly different(P＜0.05). CONCLUSIONS: There are differences in CYP2A6 genotype between smokers and non-smokers in Han population with periodontitis, but the relationship between CYP2A6 genotype and inflammatory cytokines is not clear.

Spheroid co-culture of BMSCs with osteocytes yields ring-shaped bone-like tissue that enhances alveolar bone regeneration.

Oral and maxillofacial bone defects severely impair appearance and function, and bioactive materials are urgently needed for bone regeneration. Here, we spheroid co-cultured green fluorescent protein (GFP)-labeled bone marrow stromal cells (BMSCs) and osteocyte-like MLO-Y4 cells in different ratios (3:1, 2:1, 1:1, 1:2, 1:3) or as monoculture. Bone-like tissue was formed in the 3:1, 2:1, and 1:1 co-cultures and MLO-Y4 monoculture. We found a continuous dense calcium phosphate structure and spherical calcium phosphate similar to mouse femur with the 3:1, 2:1, and 1:1 co-cultures, along with GFP-positive osteocyte-like cells encircled by an osteoid-like matrix similar to cortical bone. Flake-like calcium phosphate, which is more mature than spherical calcium phosphate, was found with the 3:1 and 2:1 co-cultures. Phosphorus and calcium signals were highest with 3:1 co-culture, and this bone-like tissue was ring-shaped. In a murine tooth extraction model, implantation of the ring-shaped bone-like tissue yielded more bone mass, osteoid and mineralized bone, and collagen versus no implantation. This tissue fabricated by spheroid co-culturing BMSCs with osteocytes yields an internal structure and mineral composition similar to mouse femur and could promote bone formation and maturation, accelerating regeneration. These findings open the way to new strategies in bone tissue engineering.

Tough, Instant, and Repeatable Adhesion of Self-Healable Elastomers to Diverse Soft and Hard Surfaces.

Repeatability and high adhesion toughness are usually contradictory for common polymer adhesives. Repeatability requires temporary interactions between the adhesive and the substrate, while high adhesion toughness is usually achieved by permanent bonding. Integrating these two features into one adhesive system is still a daunting challenge. Here, the development of a series of viscoelastic elastomers composed of a soft and hard segment is reported, which exhibit tough, instant, yet repeatable adhesion to a variety of soft and hard surfaces. Such a combination of mutually exclusive properties is attributed to the synergy of high mobility of polymer chains and massive viscoelastic dissipation of the elastomers around the interface. By optimizing the relaxation time and mechanical dissipation, the resulting adhesives can achieve a tough yet repeatable adhesion toughness above 2000 J m-2 , superior to the best-in-class commercial adhesives. Numerous acrylate monomers are proven applicable to the preparation of such adhesives, validating the universality of the fabrication method. The application of these elastomers as adhesive and protective layers in soft electronics by virtue of their universal and tough adhesion to various soft and hard substrates is also demonstrated.

[Cone-beam CT study of the characteristics of midpalatal suture at different age groups in a southern China population].

PURPOSE: The purpose of this cone-beam CT (CBCT) based study was to investigate the stages of palatal suture at different age groups as well as the bone density of the palatal suture in a south Chinese population. METHODS: The CBCT data of 113 patients with an age range from 4 to 36 years old were selected. All of them were reported to have normal growth. CBCT image data were selected in accordance with the inclusion criteria. By using Angelieri method, the palate was divided into 5 groups, and Chad Evans Larson bone density ratio was calculated for each patient. One-way ANOVA and LSD analysis were used to evaluate the average bone density ratio of the mid-palatal at each age stage as well as the mean value of palatal suture bone density at different stages with SPSS 22.0 software package. RESULTS: By comparing the density ratio of mid-palatal suture for each age group, no significant difference was noticed for the same stage regardless of the age (stage B, C and D) (P＞0.05), significant difference was noticed between C and D(P＜0.05),no significant difference was noticed for the suture density between group A and B as well as group C and D (P＞0.05), significant difference was found for the suture density between A/C, A/D, A/E, B/C, B/D, B/E, C/D, and C/E groups(P＜0.05). CONCLUSIONS: The mid-palatal suture density in children under 15 years may belong to stage A, B or C , which is significantly lower than group D and E; Patients of a palatal stage C stay within an age range from 11 to 18. No inner group difference is noticed inside group C. The average suture density of group C is significantly larger than group A and B, whereas smaller than group D and E. The results showed that CBCT can be a useful tool to guide rapid mid-palatal expansion in clinical practice. Patients who have a lower density mid-palatal suture can be expanded.

Associations of Salivary BPIFA1 Protein in Chronic Periodontitis Patients with Type 2 Diabetes Mellitus.

AIMS: To explore the differences in salivary BPI fold containing family A, member 1 (BPIFA1) concentration among type 2 diabetes mellitus (T2DM) subjects with various severities of chronic periodontitis and to determine whether BPIFA1 in saliva can be used as a potential biomarker of T2DM. METHODS: Unstimulated saliva samples were collected from 44 subjects with T2DM and 44 without T2DM (NDM). Additionally, demographic data and general health parameters, including fasting blood glucose (FBG) and body mass index (BMI), were collected. We also detected full-mouth clinical periodontal parameters including probing pocket depth (PPD), clinical attachment level (CAL), bleeding index (BI), and plaque index (PLI). Salivary BPIFA1, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) concentrations were also detected. RESULTS: BPIFA1 in saliva was detected at relatively high levels. T2DM subjects had decreased salivary BPIFA1 concentrations (P = 0.031). In T2DM subjects with nonperiodontitis or severe periodontitis, the level of BPIFA1 was significantly lower compared with that of NDM. Salivary TNF-α concentration displayed a similar trend to BPIFA1 in the NDM group. CONCLUSIONS: BPIFA1 protein is rich in saliva and might be used as a potential predictive biomarker of T2DM, especially in patients with severe periodontitis and nonperiodontitis. This trial is registered with ChiCTR-ROC-17010310.

Salvage for pectoralis major myocutaneous flap failure in head and neck reconstruction by microvascular flap.

The pectoralis major myocutaneous pedicled flap (PMMPF) - the "workhorse" for head and neck reconstruction - is associated with a high incidence of complications in certain cases. This study presents free tissue transfer as an alternative salvage technique after PMMPF failure in head and neck reconstruction. It includes seven consecutive patients who underwent free tissue salvage after PMMPF failure in head and neck reconstruction from January 2008 to September 2010 at Kaohsiung Medical University Hospital, Taiwan. Four vertical rectus abdominis myocutaneous (VRAM) flaps were applied for tongue and mouth floor defects, while three anterolateral thigh (ALT) flaps were used for mouth floor, buccal, and cheek defects. All flaps survived uneventfully, and normal oral feeding was achieved without major complications. Free tissue transfer has several advantages and can be successfully employed in head and neck reconstruction, and it is also a reliable salvage procedure after PMMPF failure in such cases.