Implantable SDF-1α-loaded silk fibroin hyaluronic acid aerogel sponges as an instructive component of the glioblastoma ecosystem: Between chemoattraction and tumor shaping into resection cavities.

In view of inevitable recurrences despite resection, glioblastoma (GB) is still an unmet clinical need. Dealing with the stromal-cell derived factor 1-alpha (SDF-1α)/CXCR4 axis as a hallmark of infiltrative GB tumors and with the resection cavity situation, the present study described the effects and relevance of a new engineered micro-nanostructured SF-HA-Hep aerogel sponges, made of silk fibroin (SF), hyaluronic acid (HA) and heparin (Hep) and loaded with SDF-1α, to interfere with the GB ecosystem and residual GB cells, attracting and confining them in a controlled area before elimination. 70 µm-pore sponges were designed as an implantable scaffold to trap GB cells. They presented shape memory and fit brain cavities. Histological results after implantation in brain immunocompetent Fischer rats revealed that SF-HA-Hep sponges are well tolerated for more than 3 months while moderately and reversibly colonized by immuno-inflammatory cells. The use of human U87MG GB cells overexpressing the CXCR4 receptor (U87MG-CXCR4+) and responding to SDF-1α allowed demonstrating directional GB cell attraction and colonization of the device in vitro and in vivo in orthotopic resection cavities in Nude rats. Not modifying global survival, aerogel sponge implantation strongly shaped U87MG-CXCR4+ tumors in cavities in contrast to random infiltrative growth in controls. Overall, those results support the interest of SF-HA-Hep sponges as modifiers of the GB ecosystem dynamics acting as "cell meeting rooms" and biocompatible niches whose properties deserve to be considered toward the development of new clinical procedures. STATEMENT OF SIGNIFICANCE: Brain tumor glioblastoma (GB) is one of the worst unmet clinical needs. To prevent the relapse in the resection cavity situation, new implantable biopolymer aerogel sponges loaded with a chemoattractant molecule were designed and preclinically tested as a prototype targeting the interaction between the initial tumor location and its attraction by the peritumoral environment. While not modifying global survival, biocompatible SDF1-loaded hyaluronic acid and silk fibroin sponges induce directional GB cell attraction and colonization in vitro and in rats in vivo. Interestingly, they strongly shaped GB tumors in contrast to random infiltrative growth in controls. These results provide original findings on application of exogenous engineered niches that shape tumors and serve as cell meeting rooms for further clinical developments.

Insights into Healthcare Professionals' Perceptions and Attitudes toward Nanotechnological Device Application: What Is the Current Situation in Glioblastoma Research?

Nanotechnology application in cancer treatment is promising and is likely to quickly spread worldwide in the near future. To date, most scientific studies on nanomaterial development have focused on deepening the attitudes of end users and experts, leaving clinical practice implications unexplored. Neuro-oncology might be a promising field for the application of nanotechnologies, especially for malignant brain tumors with a low-survival rate such as glioblastoma (GBM). As to improving patients' quality of life and life expectancy, innovative treatments are worth being explored. Indeed, it is important to explore clinicians' intention to use experimental technologies in clinical practice. In the present study, we conducted an exploratory review of the literature about healthcare workers' knowledge and personal opinions toward nanomedicine. Our search (i) gives evidence for disagreement between self-reported and factual knowledge about nanomedicine and (ii) suggests the internet and television as main sources of information about current trends in nanomedicine applications, over scientific journals and formal education. Current models of risk assessment suggest time-saving cognitive and affective shortcuts, i.e., heuristics support both laypeople and experts in the decision-making process under uncertainty, whereas they might be a source of error. Whether the knowledge is poor, heuristics are more likely to occur and thus clinicians' opinions and perspectives toward new technologies might be biased.

Antitumor activity of solamargine in mouse melanoma model: relevance to clinical safety.

Melanoma is the most aggressive type of skin cancer, and thus it is important to develop new drugs for its treatment. The present study aimed to examine the antitumor effects of solamargine a major alkaloid heteroside present in Solanum lycocarpum fruit. In addition solamargine was incorporated into nanoparticles (NP) of yttrium vanadate functionalized with 3-chloropropyltrimethoxysilane (YVO4:Eu3+:CPTES:SM) to determine antitumor activity. The anti-melanoma assessment was performed using a syngeneic mouse melanoma model B16F10 cell line. In addition, systemic toxicity, nephrotoxic, and genotoxic parameters were assessed. Solamargine, at doses of 5 or 10 mg/kg/day administered subcutaneously to male C57BL/6 mice for 5 days, decreased tumor size and frequency of mitoses in tumor tissue, indicative of a decrease in cell proliferation. Treatments with YVO4:Eu3+:CPTES:SM significantly reduced the number of mitoses in tumor tissue, associated with no change in tumor size. There were no apparent signs of systemic toxicity, nephrotoxicity, and genotoxicity initiated by treatments either with solamargine alone or plant alkaloid incorporated into NP. The animals treated with YVO4:Eu3+:CPTES:SM exhibited significant increase in spleen weight accompanied by no apparent histological changes in all tissues examined. In addition, animals treated with solamargine (10 mg/kg/day) and YVO4:Eu3+:CPTES:SM demonstrated significant reduction in hepatic DNA damage which was induced by tumor growth. Therefore, data suggest that solamargine may be considered a promising candidate in cancer therapy with no apparent toxic effects.

Anti-melanoma effect of ruthenium(II)-diphosphine complexes containing naphthoquinone ligand.

The use of natural products as potential ligands has been explored as a strategy in the development of metal-based chemotherapy. Since ruthenium complexes are promising alternatives to traditional antitumor agents, this study evaluated the anti-melanoma potential of two ruthenium(II) complexes containing the naphthoquinone ligands lapachol (lap), [Ru(lap)(dppm)2]PF6, and lawsone (law), [Ru(law)(dppm)2]PF6, in addition to the bis(diphenylphosphino)methane (dppm) ligand, referred to as complexes (1) and (2), respectively, using a syngeneic murine melanoma model. Activation of the apoptotic pathway by the treatments was assessed by immunohistochemistry in tumor tissue. Additionally, toxicity of the treatments was evaluated by variation in body and organ weight, quantification of biochemical indicators of renal damage, and genotoxicity in bone marrow and hepatocytes. First, the antiproliferative activity of (1) and (2) was observed in B16F10 cells, with IC50 values of 2.78 and 1.68 µM, respectively. The results obtained in mice showed that, unlike complex (1), (2) possesses significant anti-melanoma activity demonstrated by a reduction in tumor volume and mass (88.42%), as well as in mitosis frequency (83.86%). Additionally, complex (2) increased the levels of cleaved caspase-3, inducing tumor cell apoptosis. When compared to the metallodrug cisplatin, complex (2) exhibited similar anti-melanoma activity and lower toxicity considering all parameters evaluated. In silico studies demonstrated no difference in the binding energy of the naphthoquinone complex between complexes (1) and (2). However, the complex containing the lawsone ligand has a lower molar volume, which may be important for interactions with minor DNA grooves. The present results demonstrate the antitumor efficiency of complex (2) and a significantly lower systemic toxicity compared to cisplatin.

Styrax camporum, a typical species of the Brazilian cerrado, attenuates DNA damage, preneoplastic lesions and oxidative stress in experimental rat colon carcinogenesis.

Styrax camporum Pohl, a typical species from the Brazilian cerrado, commonly known as "benjoeiro", is used to treat gastroduodenal diseases. In previous studies carried out by our research group, hydroalcoholic extract of S. camporum stems (SCHE) exhibited antigenotoxic and antiproliferative effects. For a comparative analysis of the chemopreventive effect of SCHE, the aim of this study was to investigate the influence of SCHE against carcinogen 1,2-dimethylhydrazine (DMH)-induced DNA damage and pre-neoplastic lesions in Wistar rat colon. Animals were treated orally with SCHE at 250, 500 or 1000 mg/kg body weight in conjunction with a subcutaneous injection of DMH. DNA damage was assessed using the comet assay while tpre-neoplastic lesions by aberrant crypt foci (ACF) assay. The following hepatic oxidative stress markers were determined including activities of catalase (CAT) and glutathione S-transferase (GST) as well as levels of reduced glutathione (GSH) and malondialdehyde (MDA). Treatment with SCHE was not genotoxic or carcinogenic at the highest dose tested (1000 mg/kg b.w.). The extract effectively inhibited DNA damage and pre-neoplastic lesions induced by DMH administration at all concentrations tested. Measurement of CAT, and GST activities and levels of GSH showed that SCHE did not reduce oxidative processes. In contrast, treatment with SCHE (1000 mg/kg b.w.) decreased liver MDA levels. Taken together, these findings suggested the chemopreventive effect attributed to SCHE in colon carcinogenesis, may be related to its capacity to inhibit DNA damage as well as an antioxidant action associated with its chemical constituents egonol and homoegonol.

Evaluation of the antiseptic and wound healing potential of polyhexamethylene guanidine hydrochloride as well as its toxic effects.

The synthetic polyhexamethylene guanidine hydrochloride (PHMGH) polymer presents antifungal and antimicrobial activities in vitro. However, in vivo reports regarding its antiseptic and healing activity are scarce in the scientific literature. Thus, the present study aimed to evaluate the antimicrobial and healing effects, as well as toxicological parameters, of a topical solution containing 0.5% PHMGH (Akwaton®) in the treatment of superficial skin wounds experimentally induced on the dorsum of rodents. In addition, non-clinical safety studies were also conducted for use in human health, such as acute oral toxicity and genotoxicity tests. Animals did clinically not present dermatitis. After two days of topical treatment, PHMGH showed a significant antiseptic effect compared to the untreated group, reducing the number of colony-forming units by 72%, reaching 100% on the fourth day of treatment. The animals treated with PHMGH showed a significant area reduction of the skin lesions in relation to the untreated group, indicating a healing effect of the polymer. Moreover, PHMGH treatment led to a significant increase in fibroblasts when compared to the untreated group, revealing its healing action. No significant differences were observed between the biochemical indicators of hepatoxicity and nephrotoxicity, nor genotoxicity between the PHMGH-treated and the negative control groups. The results of acute oral toxicity showed that PHMGH at 5% presents a lethal dose 50% greater than the 2000 mg/kg. At a concentration of 5%, PHMGH did not show genotoxicity nor cytotoxicity at doses up to 1500 mg/kg through the micronucleus assay in mice. Therefore, 0.5% PHMGH showed an antimicrobial and healing effect, with no toxicity, and could be a promising adjunct in the microbial control of healing wounds.

Anti-Melanoma Activity of Indomethacin Incorporated into Mesoporous Silica Nanoparticles.

Melanoma is the deadliest type of skin cancer. Treatments that directly address tumor survival are required. Indomethacin (IND) is a well-known drug used worldwide. Although widely used as a therapeutic agent, IND has undesirable gastrointestinal effects. PURPOSE: To investigate the antitumor efficacy of IND incorporated into mesoporous silica nanoparticles (MSNPs+IND), as well as its toxic potential in a syngeneic murine B16 melanoma model. METHODS: Antitumor activity was evaluated by measuring tumor size and weight and by histopathological analysis. Possible molecular signaling pathways involved in the antitumor activity were analyzed by Western blot in liver tissue and by immunohistochemistry in tumor tissue. The potential toxicity was evaluated by determining body and organ weights and by biochemical and genotoxic analysis. RESULTS: MSNPs+IND treatments inhibited tumor growth by up to 70.09% and decreased the frequency of mitosis in tumor tissues, which was up to 37.95% lower compared to the IND groups. In hepatic tissue, COX-2 levels decreased significantly after treatment with MSNPs+IND and IND. Additionally, MSNPs+IND and IND increased the levels of cleaved caspase-3 (156.25% and 137.50%, respectively), inducing tumor cell apoptosis. Genotoxicity was limited to the group treated with the higher concentration of IND, while MSNPs prevented IND-induced genotoxicity. CONCLUSIONS: MSNPs may be promising for future applications in cancer therapy.

Betulinic acid modulates urethane-induced genotoxicity and mutagenicity in mice and Drosophila melanogaster.

Betulinic acid (BA) is a pentacyclic triterpenoid found in several plant species. Urethane (URE) is a known promutagen. Here, we examine the genotoxicity and mutagenicity of BA alone or in combination with URE using the bone marrow micronucleus assay in mice bone marrow cells and the Somatic Mutation and Recombination Test in Drosophila melanogaster. Findings revealed that BA alone was not genotoxic, but reduced the frequency of micronucleus when compared to the positive control. No significant differences were observed in the cytotoxicity. Biochemical analyzes showed no significant differences for liver (AST and ALT) or renal (creatinine and urea) function parameters, indicating the absence of hepatotoxic and nephrotoxic effects. BA alone did not increase the frequency of mutant spots, but reduced the total frequency of mutant spots when co-administered with URE in both ST and HB crosses. In addition, BA reduced the recombinogenic effect of URE at the highest concentrations of both crosses. In conclusion, under experimental conditions, BA has modulatory effects on the genotoxicity induced by URE in mice, as well as in somatic cells of D. melanogaster. We suggest that the modulatory effects of BA may be mainly due to its antioxidant and apoptotic properties.

Antibacterial and Cytotoxic Activities of Pinus tropicalis and Pinus elliottii Resins and of the Diterpene Dehydroabietic Acid Against Bacteria That Cause Dental Caries.

Considering the impact of dental caries on public health and the wide biological potential described for species belonging to the genus Pinus, here we investigate the antibacterial activity of the P. elliottii and P. tropicalis resins and of the diterpene dehydroabietic acid (DHA) against cariogenic bacteria. For this purpose, we have determined the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the resins and of the diterpene. We have also investigated the biofilm inhibition ability (through MBIC50 determination), as well as the synergistic effect (through fractional inhibitory concentration index) and the cytotoxic potential (through XTT assay) of the P. elliottii and P. tropicalis resins. The resins gave promising MIC and MBC values, which ranged from 12.5 to 400 µg/mL; DHA provided MIC and MBC values ranging from 25 to 400 µg/mL. The MICB50 values ranged from 0.78 to 400 µg/mL for the resins. Neither additive nor synergistic effects emerged for the combinations of one of the resins with chlorhexidine. The cytotoxic activity was ≥312.5 and ≥156.3 µg/mL for the P. elliottii and P. tropicalis resins, respectively. The resins showed antibacterial activity against planktonic and sessile cariogenic bacteria. These data are relevant and encourage further research into these plants, which may contribute to the discovery of new substances that can inhibit the growth of cariogenic microorganisms and reduce the incidence of dental caries.

Europium(III)-doped yttrium vanadate nanoparticles reduce the toxicity of cisplatin.

The aim of this study was to evaluate the antitumor efficiency of chemotherapy with cisplatin alone and incorporated into europium(III)-doped yttrium vanadate nanoparticles functionalized with 3­chloropropyltrimethoxysilane with folic acid and without folic acid in a syngeneic mouse melanoma model. Histopathological, biochemical and genotoxic analyses of treated animals were performed to assess the toxicity of treatments. The treatment of the animals with cisplatin alone and the nanoparticles functionalized with cisplatin at a dose of 5 mg/kg b.w. for 5 days reduced tumor weight about 86% and 65%, respectively. Histopathological analysis showed lower mean frequency of mitoses in tumor tissue of the groups receiving cisplatin alone (90% reduction) and the nanoparticles functionalized with cisplatin (70% reduction) compared to the tumor control group. A reduction in body and liver weight and an increase in serum creatinine and urea levels were observed in animals treated with CDDP, but not in those receiving the nanoparticles functionalized with cisplatin. Genotoxicity assessment by the comet assay revealed lower frequencies of DNA damage in animals treated with the nanoparticles functionalized with cisplatin (mean score = 140.80) compared to those treated with cisplatin alone (mean score = 231.80). Marked toxic effects were observed in animals treated with cisplatin alone, while treatment with the nanoparticles functionalized with cisplatin showed no toxicity. Moreover, folic acid in the inorganic nanoparticles reduced the genotoxicity of cisplatin in the bone marrow micronucleus test (10 ±â€¯1.4 and 40 ±â€¯0.0 micronucleus, respectively). These results demonstrate the antitumor efficiency and significantly reduced systemic toxicity of the nanoparticles compared to CDDP.

Testing of Schefflera vinosa extract in mammalian cells in vitro and in vivo for potential toxicity, genetic damage, and role of oxidation.

The aim of this study was to examine the cytotoxic and genotoxic potential of a hydroethanolic extract of Schefflera vinosa (SV), a plant with schistosomicidal activity, as well as its influence on DNA damage induced by different mutagens, methyl methane sulfonate (MMS) and hydrogen peroxide (H2O2), in V79 cells and Swiss mice. Schefflera vinosa extract produced cytotoxicity at concentrations of 312.5 µg/ml or higher using the XTT cell proliferation assay kit. Treatment of V79 cell cultures with the highest SV concentration tested (150 µg/ml) significantly increased the frequency of micronuclei (MN) compared to controls. All SV concentrations significantly reduced the frequency of MN induced by hydrogen peroxide in V79 cell cultures. Further, SV was able to scavenge free radicals in the DPPH assay. In the in vivo test system, treatment with the highest dose tested (1,000 mg/kg body weight) induced a significant rise in frequency of DNA damage using the comet assay. However, animals treated with different doses of SV demonstrated absence of genotoxicity in the bone marrow MN test. For assessment of modulatory effects, the lower concentration of SV (250 mg/kg body weight) administered to MMS-treated mice significantly reduced frequency of DNA damage compared to the positive control (MMS alone). In contrast, the highest concentration tested (1,000 mg/kg body weight) significantly increased the rate of MN induced by MMS. The lack of genotoxic damage at biologically relevant SV concentrations, as well as the SV-mediated antigenotoxic and antioxidant activities, indicate the potential therapeutic usefulness of this plant extract. These activities may be attributed, at least in part, to the flavonoid quercitrin, its major component.

ent-Kaurenoic acid-rich extract from Mikania glomerata: In vitro activity against bacteria responsible for dental caries.

Many studies have reported that medicinal plant extracts can inhibit oral pathogen growth or adhesion to surfaces and therefore reduce dental caries formation. The addition of these extracts to oral products like mouthwashes and dentifrices is considered an important strategy in caries control. In this sense, we have developed a Mikania glomerata extract with high ent-kaurenoic acid content (KAMg). So, this work describes the preparation of such extract and the development of a validated HPLC-DAD method to determine its ent-kaurenoic acid (KA) content. Herein it is also described the KAMg in vitro antibacterial evaluation against several cariogenic bacteria in comparison with KA and the investigation of further aspects of the KAMg activity. Toxicological aspects of the developed extract were evaluated by assessing its cytotoxicity and genotoxicity. KA and a KA-rich extract like KAMg showed to inhibit the growth of microorganisms responsible for dental caries at relatively low MIC (Minimum inhibitory concentration) values, albeit not as low as the MIC value obtained for chlorhexidine digluconate (CHD), the golden anticariogenic standard approved by the American Dental Association Council on Dental Therapeutics. However, KAMg was more effective to inhibit the formation of a Streptococcus mutans biofilm with four times lower MICB50 (minimum inhibitory concentration that reduces 50% of the biofilm) value as compared with CHD. Taking into account all these data and considering the absence of genotoxic and cytotoxic activity under the tested conditions, it is suggested that KAMg is a natural product to be considered as active ingredient in oral care products.

In vivo assessment of genotoxic, antigenotoxic and anticarcinogenic activities of Solanum lycocarpum fruits glycoalkaloidic extract.

The fruits of Solanum lycocarpum, known as wolf-fruit, are used in folk medicine, and because of that we have evaluated both the genotoxic potential of its glycoalkaloidic extract (SL) and its influence on the genotoxicity induced by methyl methanesulfonate. Furthermore, the potential blocking effect of SL intake in the initial stage of colon carcinogenesis in Wistar rats was investigated in a short-term (4-week) bioassay using aberrant crypt foci (ACF) as biomarker. The genotoxic potential was evaluated using the Swiss mice peripheral blood micronucleus test. The animals were treated with different doses of SL (15, 30 and 60 mg/kg b.w.) for 14 days, and the peripheral blood samples were collected at 48 h, 7 days and 14 days after starting the treatment. For antigenotoxicity assessment, MMS was administered on the 14th day, and after 24 h the harvesting of bone marrow and liver cells was performed, for the micronucleus and comet assays, respectively. In the ACF assay, male Wistar rats were given four subcutaneous injections of the carcinogen 1,2-dimethylhydrazine (DMH, 40 mg/kg b.w.), twice a week, during two weeks to induce ACF. The treatment with SL (15, 30 and 60 mg/kg b.w.) was given for four weeks during and after carcinogen treatment to investigate the potential beneficial effects of SL on DMH-induced ACF. The results demonstrated that SL was not genotoxic in the mouse micronucleus test. In animals treated with SL and MMS, the frequencies of micronucleus and extensions of DNA damage were significantly reduced in comparison with the animals receiving only MMS. Regarding the ACF assay, SL significantly reduced the frequency of ACF induced by DMH.

A comparative study of the modulatory effects of (-)-cubebin on the mutagenicity/recombinogenicity induced by different chemical agents.

(-)-Cubebin (CUB) is a lignan isolated from dry seeds of Piper cubeba. We aimed to assess its genotoxic potential and influence on chromosomal damage (frequency of micronuclei - MN) induced by doxorubicin (DXR) in V79 cells and by urethane (URE) in somatic Drosophila melanogaster cells. Our findings indicate an absence of a CUB-mediated genotoxic effect at the concentrations tested. The results also revealed that CUB significantly reduced the frequency of MN induced by DXR, with a mean reduction of 63.88%. In a previous study, our research group demonstrated an absence of CUB-mediated mutagenic effects through the wing Somatic Mutation and Recombination Test (SMART) in Drosophila. In the present study, we used the standard and high bioactivation versions of the SMART to estimate the antigenotoxic effects of CUB associated with URE. At lower concentrations, the recombination level decreased, but at the highest concentration, the recombination level increased. Our data and previous studies suggest that CUB may act as a free radical scavenger at low concentrations, a pro-oxidant at higher concentrations when it interacts with the enzymatic system that catalyzes the metabolic detoxification of DXR or URE, and/or an inducer of recombinational DNA repair.