[Effects of platelet-rich fibrin on canine dental pulp cells in vitro].

OBJECTIVE: To investigate the effect of platelet-rich fibrin (PRF) on the proliferation and chemotaxis capacity of autogenous canine dental pulp cells (cDPCs), and to evaluate the use of PRF as a pulp capping material in vital pulp therapy. METHODS: cDPCs were isolated and cultured from permanent anterior teeth of Beagle dogs by enzymatic methods. PRF was attained by Choukroun's protocols and the exudates of PRF were collected at the time point of the 7th day. Cell counting kit-8 (CCK-8) was applied to analyze cell proliferation. The medium of the control group was minimum essential medium alpha medium (α-MEM) containing 2% (volume fraction) fetal bovine serum (FBS). The experiment group was the exudates of PRF containing 2% FBS, and was divided into 5 groups (20%, 40%, 60%, 80%, 100%) by the volume fraction of the exudates of PRF. The 5 groups were named as PRF1, PRF2, PRF3, PRF4 and PRF5 respectively. Transwell model was used to evaluate cell chemotaxis capacity. The exudates of PRF which was most effectively in promoting cDPCs proliferation was added in the lower chamber of the experimental group; The positive control group was α-MEM containing 30% FBS and the negative control group was fresh α-MEM; The upper chamber of each group was added with 1 × 105 cells. RESULTS: The optical density of group PRF2 (1.45 ± 0.06) was significantly higher than that of the control group(1.21 ± 0.11, P<0.001). The optical density of groups PRF1, PRF3, PRF4, and PRF5 were 1.20 ± 0.02, 1.28 ± 0.04, 1.19 ± 0.02, 1.22 ± 0.02, respectively, and there was no significant difference between these groups and the control group (PRF1: P=0.902; PRF3: P=0.084; PRF4: P=0.726; PRF5: P=0.779). Therefore, the volume fraction which was most effective in promoting cell proliferation was 40%. At these concentrations the number of migrated cells was higher in PRF group(55.89 ± 18.42) than in the negative group(6.52 ± 1.97, P<0.001), but there was no significant difference between PRF group and the positive group(59.25 ± 29.17, P=0.970). CONCLUSION: PRF was a biocompatible material with cDPCs. Appropriate concentration of the exudates of PRF accelerated the proliferation and migration of cDPCs, which contributes to pulp repair in vital pulp therapy.

Integrated photo-inspired antibacterial polyvinyl alcohol/carboxymethyl cellulose hydrogel dressings for pH real-time monitoring and accelerated wound healing.

Recurrent infection of chronic wounds remains a major clinical challenge. Recently, the hydrogel antibacterial materials have attracted extensive attention for preventing infection in wound healing. In this study, a hybrid hydrogel made of polyvinyl alcohol - iodine (PAI), sodium carboxymethyl cellulose (CMC), and carbamino quantum dot (CQDs) was prepared by the cross-linking of hydrogen bonds, named as polyvinyl alcohol­iodine/sodium carboxymethyl cellulose/carbon quantum dots (PAI/CMC/CQDs). The composite hydrogels exhibited the outstanding photothermal conversion efficiency with near infrared (NIR) light irradiation, and the high antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Meanwhile, the elevated temperature of the composite hydrogels up to ∼45 °C was able to stimulate the migration of epidermal cell to accelerate skin repair. Given that PAI and CQDs could respond to different pH values (5-8), the real-time would pH information was provided by the visible light and fluorescent light dual monitoring system by naked eye. Moreover, the visible-fluorescent images could be collected and transformed into RGB signals to quantify the would pH levels, avoiding secondary injuries caused by frequent dressing changes. PAI/CMC/CQDs was demonstrated the significant therapeutic effect on chronic wounds by eliminating bacterial infections and promoting skin repair under the smart RGB monitoring system.

[Cytotoxicity of two dental materials on fibroblasts derived from human embryonic stem cells].

OBJECTIVE: To investigate the cytotoxicity of calcium hydroxide (CH) and composite resin on fibroblasts derived from human embryo body fibroblasts-H9 (EBf-H9), human dental pulp cells (hDPCs) and immortalized fibroblasts L929; and to evaluate the use of EBf-H9 as a cellular model for cytotoxicity screening of dental materials. METHODS: The EBf-H9 cells were derived from human embryonic stem cells (H9) via outgrowth of embryonic body (EB); hDPCs were isolated from healthy dental pulp, and identified by immunochemical staining. Cell Counting Kit-8 (CCK-8) assay was applied to analyze the cytotoxicity of CH and composite resin with serial concentrations on the 3 kinds of cells. RESULTS: Following 24 h and 48 h (or 72 h) post-treatment of CH and composite resin, the viability of L929 cells was significantly lower than that of EBf-H9 and hDPCs (P<0.05), and there was no significant difference between the last two groups (P>0.05). CONCLUSION: Immortalized fibroblasts L929 cells exhibited different response to CH and composite resin compared with EBf-H9 and hDPCs, and the last two cell types were similar to each other. This study indicated that fibroblasts derived from human embryonic stem cells were a potential cellular model instead of traditional immortalized murine cell line for cytotoxicity screening assay.

Tooth defects of EEC and AEC syndrome caused by heterozygous TP63 mutations in three Chinese families and genotype-phenotype correlation analyses of TP63-related disorders.

BACKGROUND: Ectrodactyly-Ectodermal dysplasia-Cleft lip/palate (EEC) syndrome and Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) syndrome belong to p63 syndromes, a group of rare disorders exhibiting a wide variety of clinical manifestations. TP63 mutations have been reported to be associated with both EEC and AEC. METHODS: Analysis of whole exome sequencing (WES) from patients with EEC or AEC syndrome and Sanger sequencing from family members. RESULTS: We confirmed that three Chinese pedigrees affected with EEC or AEC harboring a distinct TP63 mutation, and described novel clinical phenotypes of EEC and AEC, including the presence of cubitus valgus deformity and taurodontism, which were discordant to their classical disease features. We also analyzed the genotype-phenotype correlation based on our findings. CONCLUSION: We reported that the cubitus valgus deformity in patients with EEC and severe taurodontism in a patient with AEC had not been mentioned previously. Our study expands the phenotypic spectrum of EEC and AEC syndrome.

Polydopamine Nanoparticles Enhance Drug Release for Combined Photodynamic and Photothermal Therapy.

Our study shows a facile two-step method which does not require the use of core templates to load a hydrophobic photosensitizer drug chlorin e6 (Ce6) within polydopamine (PDA) nanoparticles (NPs) while maintaining the intrinsic surface properties of PDA NPs. This structure is significantly different from hollow nanocapsules which are less stiff as they do not possess a core. To our knowledge, there exist no similar studies in the literature on drug loading within the polymer matrix of PDA NPs. We characterized the drug loading and release behavior of the photosensitizer Ce6 and demonstrated the therapeutic efficacy of the combined photodynamic (PDT) and photothermal therapy (PTT) from Ce6 and PDA, respectively, under a single wavelength of 665 nm irradiation on bladder cancer cells. We obtained a saturated loading amount of 14.2 ± 0.85 µM Ce6 in 1 nM PDA NPs by incubating 1 mg/mL dopamine solution with 140 µM of Ce6 for 20 h. The PDA NPs maintained colloidal stability in biological media, whereas the pi-pi (π-π) interaction between PDA and Ce6 enabled a release profile of the photosensitizer until day 5. Interestingly, loading of Ce6 in the polymer matrix of PDA NPs significantly enhanced the cell uptake because of endocytosis. An increased cell kill was observed with the combined PDT + PTT from 1 nM PDA-Ce6 compared to that with PTT alone with 1 nM PDA and PDT alone with 15 µM equivalent concentration of free Ce6. PDA-Ce6 NPs could be a promising PDT/PTT therapeutic agent for cancer therapy.

Study on ß-cyclodextrin-complexed nanogels with improved thermal response for anticancer drug delivery.

For achievement of controllability in drug delivery, development of nanocarriers with thermal response is one of the most investigated stimulative strategies for oncological treatment. How to improve the thermosensitivity of the nanocarriers is an important factor for their successful drug delivery applications. In this study, a kind of complexed nanogels (PNACD) was developed by incorporating ß-cyclodextrin (ß-CD) into the nanogels of copolymers of N-isopropylacrylamide (NIPAM) and acrylic acid (AA) during their polymerization via in situ crosslinking of N,N'-methylenebisacrylamide (MBA) as a crosslinker. The complexed PNACD nanogels displayed a significantly enhanced thermosensitivity near body temperature compared to the ß-CD-free nanogels (PNA), which is probably associated with the rapid volumetric transformation during heating/cooling process due to the formation of complexed (decomplexed) structure between ß-CD and PNIPAM element. The PNACD nanogels can be used for loading of an anticancer drug (doxorubicin, DOX) with an encapsulation efficiency of 54±5%. The DOX-loaded nanogels displayed pH-/thermo-dual responsivenesses in drug release, which can be effectively internalized into KB cells (a human epithelial carcinoma cell line) to exert good anticancer bioactivity. This approach may enlighten design of novel nanocarriers for delivery of drugs beyond anticancer chemotherapeutic reagents.

Multistimulative Nanogels with Enhanced Thermosensitivity for Intracellular Therapeutic Delivery.

The flexibility and hydrophilicity of nanogels suggest their potential for the creation of nanocarriers with good colloidal stability and stimulative ability. In the present study, biocompatible AGP and AGPA nanogels with triple-stimulative properties (thermosensitivity, pH sensitivity, and redox sensitivity) were prepared by incorporating poly(N-isopropylacrylamide) (PNIPAM) or poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-AA)) into alginate (AG) emulsion nanodrops, followed by fixation with a disulfide-containing molecule (cystamine dihydrochloride (Cys)). Compared to AG/PNIPAM(AGP) nanogels, AG/P(NIPAM-AA) (AGPA) nanogels exhibited more sensitive volumetric expansion by switching the temperature from 40 to 25 °C under physiological medium. This expansion occurs because P(NIPAM-AA) with -COOH groups can be fixed inside the nanogels via chemical bonding with Cys, whereas PNIPAM was encapsulated in the nanogels through simple physical interactions with the AG matrix. AGPA nanogels carrying an anticancer drug tend to easily enter cells upon heating, thereby exerting toxicity through a cold shock and reverse thermally induced release of an anticancer drug. Upon internalization inside cells, the nanogels use the reducible and acidic intracellular environments to effectively release the drug to the nucleus to impart anticancer activity. These results demonstrate that multifunctional nanogels may be used as a general platform for therapeutic delivery.

Therapeutic effects of hepatocyte growth factor-overexpressing dental pulp stem cells on liver cirrhosis in a rat model.

Cirrhosis is the terminal stage of hepatic diseases and is prone to develop into hepatocyte carcinoma. Increasing evidence suggests that the transplantation of dental pulp stem cells (DPSCs) may promote recovery from cirrhosis, but the key regulatory mechanisms involved remain to be determined. In this study, we overexpressed human hepatocyte growth factor (hHGF) in primary rat DPSCs and evaluated the effects of HGF overexpression on the biological behaviors and therapeutic efficacy of grafted DPSCs in cirrhosis. Liver cirrhosis was induced via the intraperitoneal injection of CCl4 twice weekly for 12 weeks and was verified through histopathological and serological assays. HGF was overexpressed in DPSCs via transduction with a hHGF-lentiviral vector and confirmed based on the elevated expression and secretion of HGF. The HGF-overexpressing DPSCs were transplanted into rats intravenously. The HGF-overexpressing DPSCs showed increased survival and hepatogenic differentiation in host liver tissue at 6 weeks after grafting. They also exhibited a significantly greater repair potential in relation to cirrhosis pathology and impaired liver function than did DPSCs expressing HGF at physiological levels. Our study may provide an experimental basis for the development of novel methods for the treatment of liver cirrhosis in clinical practice.

A Novel AXIN2 Missense Mutation Is Associated with Non-Syndromic Oligodontia.

Oligodontia is defined as the congenital absence of six or more permanent teeth, excluding the third molars. Oligodontia may contribute to masticatory dysfunction, speech alteration, aesthetic problems and malocclusion. Numerous gene mutations have been association with oligodontia. In the present study, we identified a de novo AXIN2 missense mutation (c.314T>G) in a Chinese individual with non-syndromic oligodontia. This mutation results in the substitution of Val at residue 105 for Gly (p.Val105Gly); residue 105 is located in the highly conserved regulator of G protein signaling (RGS) domain of the AXIN2 protein. This is the first report indicating that a mutation in the RGS domain of AXIN2 is responsible for non-syndromic oligodontia. Our study supports the relationship between AXIN2 mutation and non-syndromic oligodontia and extends the mutation spectrum of the AXIN2 gene.