High expression of aryl hydrocarbon receptor (AhR) plays an important role in the formation of fibrous epulis.

Objectives: Epulis is considered to be a massive reactive lesion rather than a true neoplasia. AhR is thought to be associated with inflammation and development of neoplasms. Here, we aimed to observe the expression of AhR in fibrous epulis and explore its role and possible mechanism in the pathogenesis of epulis.

Bioreducible crosslinked cationic nanopolyplexes from clickable polyethylenimines enabling robust cancer gene therapy.

Bioreducible crosslinked polyplexes from branched polyethylenimine (BPEI, 10 kDa) were successfully constructed through DNA neutralization by disulfide-linked azidated BPEI (PAZ) and subsequent DNA condensation by azadibenzocyclooctyne-modified BPEI (PDB), following their self-crosslinking via azide-azadibenzocyclooctyne click chemistry. Click-crosslinked cationic polyplexes (c-polyplexes) revealed high extracellular colloidal stability against negative heparin and ions while intracellular bioreducible degradability for efficient gene unpacking. In vitro gene transfection in cancer cells indicated that the c-polyplexes produced markedly higher transfection efficiency than non-crosslinked counterparts in the serum.

Injectable dextran hydrogels fabricated by metal-free click chemistry for cartilage tissue engineering.

Injectable dextran-based hydrogels were prepared for the first time by bioorthogonal click chemistry for cartilage tissue engineering. Click-crosslinked injectable hydrogels based on cyto-compatible dextran (Mw=10kDa) were successfully fabricated under physiological conditions by metal-free alkyne-azide cycloaddition (click) reaction between azadibenzocyclooctyne-modified dextran (Dex-ADIBO) and azide-modified dextran (Dex-N). Gelation time of these dextran hydrogels could be regulated in the range of approximately 1.

[Survival of bone marrow mesenchymal stem cells and periodontal ligament stem cells in cell sheets].

Objective: To evaluate the survival of bone marrow mesenchymal stem cells (BMMSC) and periodontal ligament stem cells (PDLSC) in BMMSC/PDLSC cell sheets which transplanted ectopically into subcutaneous dorsum of nude mice.

Methods: The canine BMMSC and PDLSC from primary culture were tranfected with lentiviral vectors carrying green fluorescent protein (GFP) gene (Lentivirus-GFP) or red fluorescent protein (RFP) gene (Lentivirus-RFP) respectively. The immunophenotypes of GFP-labeled BMMSC and RFP-labeled PDLSC were identified by flow cytometry.

A pH and redox dual responsive 4-arm poly(ethylene glycol)-block-poly(disulfide histamine) copolymer for non-viral gene transfection in vitro and in vivo.

A novel 4-arm poly(ethylene glycol)-b-poly(disulfide histamine) copolymer was synthesized by Michael addition reaction of poly(ethylene glycol) (PEG) vinyl sulfone and amine-capped poly(disulfide histamine) oligomer, being denoted as 4-arm PEG-SSPHIS. This copolymer was able to condense DNA into nanoscale polyplexes (<200 nm in average diameter) with almost neutral surface charge (+(5-10) mV). Besides, these polyplexes were colloidal stable within 4 h in HEPES buffer saline at pH 7.

[Root canal treatment of mandibular first premolar with 3 root canals: a case].

The occurrence of three canals in mandibular premolars is very rare. This article reported and discussed the treatment of a mandibular first premolar with 3 root canals, specially in aspect of root-detecting and root-shaping.