Intratumor delivery of amino-modified graphene oxide as a multifunctional photothermal agent for efficient antitumor phototherapy.

Due to the high selectivity and non-invasive property, phototherapy has attracted increasing attention in the treatment of cancer. Targeted delivery and retention of photoactive agents in tumor tissue is of great significance and importance for safe and efficient phototherapy. Herein, we report a multifunctional nanomaterial photothermal agent, namely amino-modified graphene oxide (AGO) for anti-oral cancer photothermal therapy (PTT). Compared to the parental graphene oxide (GO) which has a negative charge and weak photothermal effect, AGO possesses a positive charge (∼+50 mV) and the significantly enhanced photothermal effect. Positive charge allows AGO to efficiently interact with tumor cells and retain in tumor tissue after intratumor injection. The enhanced photothermal effect allows AGO to achieve the tunable and efficient PTT. In vitro results show that AGO (15 µg/mL) reduces the viability of HSC-3 cells (oral squamous cell carcinoma cell line) to 5% under near infrared (NIR) irradiation (temperature increased to 58.4 °C). In vivo antitumor study shows that intratumor delivery of AGO (200 µg/mouse) has no inhibition effects on tumor growth (454% of initial tumor size) without NIR. With a single dose of NIR irradiation, however, AGO significantly reduces the tumor size to 25% of initial size in 1 of 4 mice, and even induces the complete tumor ablation in 3 of 4 mice. Furthermore, the injected AGO falls off along with the scab after PTT. Our findings indicate that AGO is a potential nano-photothermal agent for tunable, convenient and efficient anticancer PTT.

Nocardia huaxiensis sp. nov., an actinomycete isolated from human skin.

A novel actinomycete, designated as strain WCH-YHL-001T, was isolated from skin biopsy specimens of a patient at West China Hospital, Chengdu, Sichuan Province, PR China. The cells were Gram-positive, aerobic, heterotrophic and non-motile. They formed an extensive substrate with short aerial mycelia, whose branches fragmented into rod-shaped elements. Growth occurred at 10-40 °C, pH 5.0-12.0 and with NaCl concentrations of 0-4.0 % (w/v). The major cellular fatty acids of strain WCH-YHL-001T were C16 : 0, C18 : 1 ω9c, C18 : 0 10-methyl and summed feature 3. The predominant respiratory quinone was MK-8 (H4ω-cycl). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol mannoside, unknown phospholipids and unidentified glycolipids. The diagnostic diamino acid of peptidoglycan was meso-diaminopimelic acid. The whole-cell sugar pattern consisted of arabinose and glucose. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain WCH-YHL-001T belonged to the genus Nocardia. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) values between strain WCH-YHL-001T and type strains of Nocardia species were lower than the cut-offs (≥95-96 % for ANI and ≥70 % for isDDH) required to define a bacterial species. The genomic DNA G+C content was 67.8 mol%. Phylogenetic, physiological and chemotaxonomic data suggested that strain WCH-YHL-001T represented a novel species of the genus Nocardia, for which the name Nocardia huaxiensis sp. nov. is proposed, with the type strain WCH-YHL-001T (=GDMCC 4.181T=JCM 34475 T=NBRC 114973T).

Drug-free and non-crosslinked chitosan scaffolds with efficient antibacterial activity against both Gram-negative and Gram-positive bacteria.

Treatment of oral pathogens is important for both oral and systemic health. The antimicrobial activity of chitosan (CS)-based scaffolds either loading antibiotics or compositing with other agents are well documented. However, the intrinsic antibacterial activity of CS scaffolds alone has never been reported. Herein, we fabricated the non-crosslinked CS scaffold and investigated its antibacterial activity against typical oral pathogens, Gram-negative Porphyromonas gingivalis and Gram-positive Streptococcus mutans. We found both pathogens were completely killed by 1 mg CS scaffolds at 6 h, due largely to the CS-induced time-dependent bacteria clustering. Interestingly, ß-glycerophosphate crosslinked scaffolds showed no antibacterial activity. In conclusion, the bactericidal activity of CS scaffolds alone is reported for the first time. Together with the biodegradability, physical stability, biocompatibility and great antibacterial activity, the non-crosslinked CS scaffolds may have great potentials not only in treating oral diseases but also in wound healing and tissue engineering.

Digestive Enzyme Corona Formed in the Gastrointestinal Tract and Its Impact on Epithelial Cell Uptake of Nanoparticles.

The fate of intravenously injected nanoparticles (NPs) is significantly affected by nano-protein interaction and corona formation. However, such an interaction between NPs and digestive enzymes occurring in the gastrointestinal tract (GIT) and its impacts on epithelial cell uptake are little known. We synthesized the poly(3-hydroxybutyrate- co-3-hydroxyhexanoate)-based cationic NPs (CNPs) and investigated the CNP-digestive enzyme interaction and its effect on the cellular uptake. The formation of enzyme corona was confirmed by size/zeta potential analysis, morphology, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and enzyme quantification. The cellular uptake of CNPs by Caco-2 cells was significantly reduced upon the formation of enzyme corona. Our findings demonstrate the digestive enzyme corona formation and its inhibited effect on the epithelial cell uptake of CNPs for the first time. Understanding the enzyme corona could offer a new insight into the fate of nanomedicines in the GIT, and this understanding would be highly beneficial for guiding future nanomedicine designs.

Organic composite-mediated surface coating of human acellular bone matrix with strontium.

Acellular bone matrix (ACBM) provides an osteoconductive scaffold for bone repair, but its osteoinductivity is poor. Strontium (Sr) improves the osteoinductivity of bone implants. In this study, we developed an organic composite-mediated strontium coating strategy for ACBM scaffolds by using the ion chelating ability of carboxymethyl cellulose (CMC) and the surface adhesion ability of dopamine (DOPA). The organic coating composite, termed the CMC-DOPA-Sr composite, was synthesized under a mild condition, and its chemical structure and strontium ion chelating ability were then determined. After surface decoration, the physicochemical properties of the strontium-coated ACBM (ACBM-Sr) scaffolds were characterized, and their biocompatibility and osteoinductivity were determined in vitro and in vivo. The results showed that the CMC-DOPA-Sr composite facilitated strontium coating on the surface of ACBM scaffolds. The ACBM-Sr scaffolds possessed a sustained strontium ion release profile, exhibited good cytocompatibility, and enhanced the osteogenic differentiation of mesenchymal stem cells in vitro. Furthermore, the ACBM-Sr scaffolds showed good histocompatibility after subcutaneous implantation in nude mice. Taken together, this study provided a simple and mild strategy to realize strontium coating for ACBM scaffolds, which resulted in good biocompatibility and improved osteoinductivity.

High efficient anti-cancer drug delivery systems using tea polyphenols reduced and functionalized graphene oxide.

Targeted drug delivery is urgently needed for cancer therapy, and green synthesis is important for the biomedical use of drug delivery systems in the human body. In this work, we report two targeted delivery systems for anticancer drugs based on tea polyphenol functionalized and reduced graphene oxide (TPGs). The obtained TPGs demonstrated an efficient doxorubicin loading capacity as high as 3.430 × 106 mg g-1 and 3.932 × 104 mg g-1, and exhibited pH-triggered release. Furthermore, the kinetic models, adsorption isotherms, and possible loading mechanisms were investigated in details. Compared to TPG1 and free doxorubicin, TPG2 is biocompatible to normal cells even at high concentrations and promotes tumor cells death by delivering the doxorubicin mainly to the nuclei. These results were confirmed using cell viability tests and confocal laser microscopy. Moreover, apoptosis tests showed that the mechanism of cancer cell death induced by TPG1 and TPG2 might follow the similar mechanisms. Taken together, these results demonstrate that TPGs provide a multifunctional drug delivery system with a greater loading capacity and pH-sensitive drug release for enhanced cancer therapy. The high drug payload capability and enhanced antitumor efficacy demonstrate that we developed systems are promising for various biomedical applications and cancer therapy.

An ultrastructural study on corkscrew hairs and cigarette-ash-shaped hairs observed by dermoscopy of tinea capitis.

This study was aimed to explain the formation mechanisms of corkscrew hairs and cigarette-ash-shaped hairs observed by dermoscopy of tinea capitis. In the present work, the ultrastructure of the involved hairs collected from a girl with tinea capitis caused by Trichophyton violaceum was observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). SEM observation of the corkscrew hair revealed bent hair shaft and asymmetrically disrupted cuticle layer. TEM findings demonstrated the hair shaft became weak. The corkscrew hairs closely covered by scales on the scalp were observed under dermoscopy. We speculate that the formation of corkscrew hairs is a result of a combination of internal damage due to hair degradation by T. violaceum and external resistance due to scales covering the hair. SEM observation of the cigarette-ash-shaped hair revealed irregularly disrupted and incompact end, which might represent the stump of the broken corkscrew hair after treatment.

TCAB1: a potential target for diagnosis and therapy of head and neck carcinomas.

BACKGROUND: WRAP53, including α, ß and γ isoforms, plays an important role not only in the stability of p53 mRNA, but also in the assembly and trafficking of the telomerase holoenzyme. It has been considered an oncogene and is thought to promote the survival of cancer cells. The aim of this study was to detect the role of TCAB1 (except WRAP53α) in the occurrence and development of head and neck carcinomas. METHODS: Immunohistochemistry was used to detect the TCAB1 expression in clinical specimen sections and performed western blotting to check the TCAB1 expression levels in cell lines. TCAB1 was depleted using shRNA lentivirus and the knockdown efficiency was assessed using q-PCR and Western blotting. We performed CCK-8 assays and flow cytometry to check the cell proliferation potential and used the trans-well assay to test the invasion ability in vitro. Xenografts were used to detect the tumor formation potential in vivo. Moreover, we performed cDNA microarray to investigate the candidate factors involved in this process. RESULTS: We observed a notable overexpression of TCAB1 in head and neck carcinoma clinical specimens as well as in carcinoma cell lines. Knockdown of TCAB1 decreased the cellular proliferation potential and invasion ability in vitro. cDNA microarray analysis suggested the possible involvement of several pathways and factors associated with tumorigenesis and carcinoma development in the TCAB1-mediated regulation of cancers. Furthermore, the xenograft assay confirmed that the depletion of TCAB1 would inhibit tumor formation in nude mice. The immunohistochemistry results of the mice tumor tissue sections revealed that the cells in shTCAB1 xenografts showed decreased proliferation potential and increased apoptotic trend, meanwhile, the angiogenesis was inhibited in the smaller tumors form shTCAB1 cells. CONCLUSIONS: Our study demonstrated that depletion of TCAB1 decreased cellular proliferation and invasion potential both in vitro and in vivo. The data indicated that TCAB1 might facilitate the occurrence and development of head and neck carcinomas. In future, TCAB1 might be useful as a prognostic biomarker or a potential target for the diagnosis and therapy of head and neck carcinomas.

Mucor irregularis infection around the inner canthus cured by amphotericin B: a case report and review of published literatures.

We report a case of primary cutaneous mucormycosis caused by Mucor irregularis. A 47-year-old farmer was presented to our clinic with the history of progressive red plaque around the inner canthus following dacryocystectomy about a year earlier. Linear, aseptate hyphae were seen by direct KOH examination and in biopsy. Fungal culture revealed light yellow filamentous colonies that were identified as Mucor irregularis by nucleotide sequencing of rRNA gene. Amphotericin B and dexamethasone were used in gradually increasing dosage. The treatment lasted 43 days, and the patient received 760 mg total amphotericin B. The patient was discharged after 2 months of treatment. The plaque became smooth, and fungal culture was negative. There was no recurrence for half a year through telephone follow-ups. A review of published studies revealed 23 cases of Mucor irregularis infection. Most cases resulted following injuries or surgical complications. Farmers and manual laborers were most at risk with males outnumbering females among patients. Amphotericin B and its liposomal preparations remain most effective treatment choices.

[Correlation between DNA damage and EB virus infection in nasopharyngeal carcinoma].

OBJECTIVE: To explore the correlation between the expression of phosphorylated histone H2AX (γ-H2AX) and Epstein-Barr virus (EBV) infection in nasopharyngeal carcinoma (NPC) specimens, and to investigate the role and mechanism of EBV-induced DNA damage in NPC tumorigenesis and development in vitro. METHODS: We enrolled 50 cases of NPC and 20 cases of nasopharyngitis (NPI) specimens to test the expressions of γ-H2AX and EBV latent membrane protein 1 (LMP1) by immunohistochemical method (IHC). And then in LMP1-negative samples, we detected the EBV-encoded RNA (EBER) using in situ hybridization. The γ-H2AX level was detected in NPC cells CNE1 before and after EBV infection using Western blotting. RESULTS: γ-H2AX was expressed in most NPC specimens (94%), which was much higher than that in NPI (40%), and EBV was presented in 94% of NPC but only 30% in NPI. Moreover, γ-H2AX was positive in 97.9% of the EBV-positive specimens, which indicated the close correlation between γ-H2AX expression and EBV infection (P<0.05). Finally, Western blotting showed that γ-H2AX level significantly increased in CNE1 cells after EBV infection. CONCLUSION: This study demonstrated that an intimate connection existed between γ-H2AX expression and EBV infection in NPC both in vivo and in vitro. EBV infection might induce DNA damage in CNE1 cells, which causes genome instability and initiates or promotes the tumorigenesis and development of NPC.

Preformed albumin corona, a protective coating for nanoparticles based drug delivery system.

The non-specific interaction between nanoparticles (NPs) and plasma proteins occurs immediately after NPs enter the blood, resulting in the formation of the protein corona that thereafter replaces the original NPs and becomes what the organs and cells really see. Consequently, the in vivo fate of NPs and the biological responses to the NPs are changed. This is one substantial reason for the two main problems of the NPs based drug delivery system, i.e. nanotoxicity and rapid clearance of NPs from the blood after intravenous injection. Here, we demonstrate the successful application of the preformed albumin corona in inhibiting the plasma proteins adsorption and decreasing the complement activation, and ultimately in prolonging the blood circulation time and reducing the toxicity of the polymeric PHBHHx NPs. Since the interaction of proteins with various nano-materials and/or -particles is ubiquitous, pre-forming albumin corona has a great potential to be a versatile strategy for optimizing the NPs based drug delivery system.

Adenovirus encoding BMP-7 immobilized on titanium surface exhibits local delivery ability and regulates osteoblast differentiation in vitro.

OBJECTIVE: The local delivery of growth factors such as bone morphogenetic protein-7 (BMP-7) into the tissues around dental implants may improve their osseointegration. We have designed a new method of attaching BMP-7 to a titanium surface and assessed both the retention of the BMP-7 and its effect on osteoblast differentiation. DESIGN: Adenoviral vector expressing BMP-7 was attached to dental titanium discs by hexon-specific antibodies in a type I collagen-avidin gel. FITC-labelled secondary antibody was used to measure the continuing adherence of the coating after repeated rinsing. Osteoblasts were harvested and seeded on the titanium discs. Gene transduction efficiency and targeting ability were assessed after 24h. Surface morphology was observed by SEM. Cell proliferation and alkaline phosphatase (ALP) activities were measured. RESULTS: The anti-adenohexon antibody adhered strongly to the collagen-avidin gels. BMP-7 gene expression was localized precisely to cells growing on the gels bound by the hexon-specific antibody. Osteoblasts on the titanium containing Ad-BMP-7 had a higher ALP activity than those without Ad-BMP-7. CONCLUSIONS: This study describes a novel technique for the precise attachment of BMP-7 to titanium surfaces. The process may enhance the osseointegration of dental implants.

The poor osteoinductive capability of human acellular bone matrix.

Demineralized bone matrix (DBM) has extensive clinical use for bone regeneration because of its osteoinductive and osteoconductive aptitude. It is suggested that the demineralization process in bone matrix preparation is influential in maintaining osteoinductivity; however, relevant investigations, especially into the osteoinductivity of acellular bone matrix, are not often performed. This study addressed the osteoinductive capability of human acellular cancellous bone matrix (ACBM) after subcutaneous implantation in a rat model. The growth and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBM-MSCs) seeded in this material were also studied. Without the demineralization process, the ACBM we obtained had an interconnected porous network and the micropores in the surface were clearly exposed. After the ACBM was subcutaneously implanted for 4 months, new osteoid formation was noted but not typical mature bone formation. rBM-MSCs grew well in the ACBM and kept a steady morphology after continuous culture for 28 days. However, no mineralized nodule formation was detected and the expression levels of genes encoding osteogenic markers were significantly decreased. These results demonstrated that human ACBM possess the structural features of native bone and poor osteoinductivity; nonetheless this material helped to preserve the undifferentiated phenotype of rBM-MSCs. Such insights may further broaden our understanding of the application of ACBM for bone regeneration and the creation of stem cell niches.

Crocin inhibits proliferation and nucleic acid synthesis and induces apoptosis in the human tongue squamous cell carcinoma cell line Tca8113.

BACKGROUND: Cancer chemoprevention is a proven effective strategy for oral squamous cell carcinoma (OSCC). The present study was designed to investigate the effects of crocin, a potential chemopreventive agent, on growth and DNA and RNA content in a human tongue squamous cell carcinoma cell line, Tca8113. METHODS: Tca8113 cells were treated with crocin for 24, 48, 72, and 96 h at concentrations of 0.1, 0.2, 0.4, and 0.8 mM. Tumor cell viability was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. In addition, Tca8113 cells were treated with 0.4 mM crocin and cytotoxic effects as an inducer of apoptosis were analyzed using flow cytometry. Furthermore, acridine orange (AO) staining and observation using laser scanning confocal microscopy (LSCM) were used to determine the effects of the drug on nucleic acid synthesis. RESULTS: Crocin decreased Tca8113 cell viability and growth remarkably at 24, 48, 72, and 96 h, in a concentration-dependent manner (P<0.05). In addition, 0.4 mM crocin significantly induced both early and late apoptosis of Tca8113 cells. Moreover, the cellular DNA and RNA content was significantly downregulated by 0.4 mM crocin compared with the negative control (P<0.01). CONCLUSIONS: Our observations support the feasibility of applying crocin as a chemoprophylactic agent and treatment for OSCCs.

[Therapeutic effects of hTR-siRNA adenovirus on human cervical cancer xenografts in nude mice].

OBJECTIVE: To study the anti-tumor effects and its mechanism of hTR-siRNA adenovirus on human cervical cancer in vivo. METHODS: The in vivo model of human cervical cancer was established by the subcutaneous inoculation of HeLa cells at the right armpit of BALB/c nu/nu mice. After successful implantation, the mice were randomized into four groups, in which the mice were intratumorally injected with 0.1 mL of Ad-hTR-siRNA (10(13) pfu/L), or Ad-NT-siRNA (10(13) pfu/L), or Cisplatin (1.20 g/L), or serum-free DMEM alone respectively. These treatments were given once every 3 days for 6 times. After the last injection, the mice were observed for 7 days continuously and sacrificed at the end. The tumors were harvasted, weighed, and sectioned. The TUNEL assay was used to assess the apoptosis of these tumor cells. RESULTS: Tumors-implanted were established successfully by 100% with HeLa cells. As compared with Ad-NT-siRNA, Ad-hTR-siRNA could slow down tumor growth, decrease tumor volume (45.48%) and tumor weight (34.68%), as well as promote the apoptosis and necrosis of tumor cells. The TUNEL positive cells were about 11.8%. But the anti-tumor activity of Ad-hTR-siRNA didn't catch on Cisplatin's. CONCLUSION: This study indicated that the hTR-siRNA adenovirus could suppress cervical cancer-xenografted growth in vivo and induce tumor cell apoptosis or necrosis.