Self-healable, tough and highly stretchable ionic nanocomposite physical hydrogels.

We present a facile strategy to synthesize self-healable tough and highly stretchable hydrogels. Our design rationale for the creation of ionic cross-linked hydrogels is to graft an acrylic acid monomer on the surface of vinyl hybrid silica nanoparticles (VSNPs) for the growth of poly(acrylic) acid (PAA), and the obtained VSNP-PAA nanobrush can be used as a gelator. Physical cross-linking through hydrogen bonding and ferric ion-mediated ionic interactions between PAA polymer chains of the gelators yielded ionic nanocomposite physical hydrogels with excellent and balanced mechanical properties (tensile strength 860 kPa, elongation at break ∼2300%), and the ability to self-repair (tensile strength ∼560 kPa, elongation at break ∼1800%). The toughness and stretchability arise from the reversible cross-linking interactions between the polymer chains that help dissipate energy through stress (deformation) triggered dynamic processes. These unique properties will enable greater application of these hydrogel materials, especially in tissue engineering.

pH-sensitive and specific ligand-conjugated chitosan nanogels for efficient drug delivery.

Nanogels have been recently attracted attentions because they exhibit significantly different behaviors compared with nanoparticles. Among them, chitosan (CS) nanogels have gained considerable attentions from researchers for in vivo applications due to bioactivity, biodegradability, mucoadhesiveness, and biocompatibility of CS. In this review, we have summarized the applications of CS nanogels for efficient drug delivery. Specifically, CS nanogels can be modified by pH-sensitive groups or specific ligands to obtain the corresponding functions. These functional CS nanogels have been used to deliver therapeutic agents, such as anti-cancer drugs, genes, and vaccines. By reviewing the recent research progress on CS nanogels in pharmaceutical applications, it will provide biomaterial researchers potential help for the development of CS nanogel delivery system to meet clinical needs.

[Clinical efficacy and safety of sublingual immunotherapy using standardized Dermatophagoides farinae extract for children with combined allergic rhinitis and asthma syndrome].

OBJECTIVE: To study the clinical efficacy of sublingual immunotherapy using standardized Dermatophagoides farinae extract for children with combined allergic rhinitis and asthma syndrome. METHODS: Fifty-two children, from 4 to 14 years of age, with mite-sensitive combined allergic rhinitis and asthma syndrome were treated sublingually with standardized Dermatophagoides farinae extract. The clinical efficacy was evaluated by monthly follow-up visits. After treatment for 1 or 2 years using the standardized Dermatophagoides farinae extract, the asthma and rhinitis symptom scores, medication scores and adverse reactions before and after treatment were evaluated. SPSS 17.0 software was used to analyze the data. RESULTS: The allergic asthma symptom scores before treatment during the day were 3.22 ± 0.66 and at night 2.05 ± 0.57. After 1 year of treatment, the day and night scores (1.68 ± 0.61, 0.94 ± 0.32) respectively, were decreased significantly (q values were 15.25 and 13.78 respectively, all P < 0.01). After 2 years of treatment, the scores (0.61 ± 0.28, 0.43 ± 0.13) were also decreased significantly (q values were 10.29 and 6.07 respectively, all P < 0.01). The allergic rhinitis symptom scores and medication scores were 2.34 ± 0.59 and 3.09 ± 1.01 respectively before treatment and 1.21 ± 0.46 and 1.89 ± 0.64 after 1 year of treatment. The differences were significant (q values were 15.48 and 18.61 respectively, all P < 0.01). The allergic rhinitis symptom scores and medication scores were 1.02 ± 0.37 and 1.49 ± 0.38 after 2 years of treatment. There was no significant difference between 2 years of treatment and 1 year of treatment (q values were 2.53 and 2.78 respectively, all P > 0.05). There were no severe adverse events during the treatment, except for mild mouth cavity discomfort. CONCLUSIONS: Sublingual immunotherapy using standardized Dermatophagoides farinae extract is safe and effective in the treatment of children with combined allergic rhinitis and asthma syndrome.

Application of a novel electrosynthesized polydopamine-imprinted film to the capacitive sensing of nicotine.

The application of novel electrosynthesized polydopamine (PDA)-imprinted film as a recognition element for the capacitive sensing of nicotine is reported. The PDA-imprinted film was electropolymerized directly on the gold electrode surface in the presence of nicotine without an additional self-assembled thiol sublayer. The compact PDA film has various functional groups that aid the imprinting procedure. Furthermore, the film shows good capacitive response since it is insulating in nature and ultrathin. The sensor's linear response range for nicotine was between 1-25 micromol L(-1), with a detection limit of 0.5 micromol L(-1). The proposed molecularly imprinted polymer capacitive (MIPC) sensor exhibited good selectivity for nicotine. The reproducibility and repeatability of the MIPC sensor were all found to be satisfactory. The results from sample analysis confirmed the applicability of the MIPC sensor to quantitative analysis.