Sodium chloride modified silica nanoparticles as a non-viral vector with a high efficiency of DNA transfer into cells

The reprotoxic adverse side effects of neurogenic and neuroprotective drugs: current use of human organoid modeling as a potential alternative to preclinical models

The management of neurological disorders heavily relies on neurotherapeutic drugs, but notable concerns exist regarding their possible negative effects on reproductive health. Traditional preclinical models often fail to accurately predict reprotoxicity, highlighting the need for more physiologically relevant systems. Organoid models represent a promising approach for concurrently studying neurotoxicity and reprotoxicity, providing insights into the complex interplay between neurotherapeutic drugs and reproductive systems. Herein, we have examined the molecular mechanisms underlying neurotherapeutic drug-induced reprotoxicity and discussed experimental findings from case studies. Additionally, we explore the utility of organoid models in elucidating the reproductive complications of neurodrug exposure. Have discussed the principles of organoid models, highlighting their ability to recapitulate neurodevelopmental processes and simulate drug-induced toxicity in a controlled environment. Challenges and future perspectives in the field have been addressed with a focus on advancing organoid technologies to improve reprotoxicity assessment and enhance drug safety screening. This review underscores the importance of organoid models in unraveling the complex relationship between neurotherapeutic drugs and reproductive health.

Exposure to zinc oxide nanoparticles induced reproductive toxicities in male Sprague Dawley rats

BACKGROUND

This research delves into the reproductive toxicology of zinc oxide nanoparticles (ZnO-NPs) in male Sprague Dawley rats. It specifically examines the repercussions of Zn accumulation in the testes, alterations in testosterone levels, and histopathological changes in the gonadal tissues.

AIMS

The primary objective of this study is to elucidate the extent of reproductive toxicity induced by ZnO-NPs in male Sprague Dawley rats. The investigation aims to contribute to a deeper understanding of the potential endocrine and reproductive disruptions caused by ZnO-NPs exposure.

METHODS

Characterization techniques including SEM-EDX and XRD affirmed the characteristic nature of ZnO-NPs. Twenty-five healthy post weaning rats (200-250 g) were intraperitoneally exposed to different concentrations of ZnO-NPs @ 10 or 20 or 30 mg/kg BW for 28 days on alternate days.

RESULTS

Results showed significant dose dependent decline in the body weight and testicular somatic index of rats. It also showed significant dose dependent accumulation of Zn in testis with increasing dose of ZnO-NPs. Conversely, serum testosterone level and sperm count were reduced with increasing dose of ZnO-NPs. Histological results showed dose dependent abnormalities i.e., vacuolization, edema, hemorrhage, destruction of seminiferous tubules, loss of germ cells and necrosis in rat testis.

CONCLUSION

The findings of this study clearly indicate that high doses of zinc oxide nanoparticles (ZnO-NPs) can adversely affect the structural integrity and functional efficacy of the male reproductive system. Given these results, it becomes crucial to implement stringent precautionary measures in the utilization of ZnO-NPs, particularly in cosmetics and other relevant sectors. Such measures are imperative to mitigate the toxicological impact of ZnO-NPs on the male reproductive system and potentially on other related physiological functions. This study underscores the need for regulatory vigilance and safety assessments in the application of nanotechnology to safeguard human health.

Safety and Toxicity Implications of Multifunctional Drug Delivery Nanocarriers on Reproductive Systems In Vitro and In Vivo

In the recent past, nanotechnological advancements in engineered nanomaterials have demonstrated diverse and versatile applications in different arenas, including bio-imaging, drug delivery, bio-sensing, detection and analysis of biological macromolecules, bio-catalysis, nanomedicine, and other biomedical applications. However, public interests and concerns in the context of human exposure to these nanomaterials and their consequential well-being may hamper the wider applicability of these nanomaterial-based platforms. Furthermore, human exposure to these nanosized and engineered particulate materials has also increased drastically in the last 2 decades due to enormous research and development and anthropocentric applications of nanoparticles. Their widespread use in nanomaterial-based industries, viz., nanomedicine, cosmetics, and consumer goods has also raised questions regarding the potential of nanotoxicity in general and reproductive nanotoxicology in particular. In this review, we have summarized diverse aspects of nanoparticle safety and their toxicological outcomes on reproduction and developmental systems. Various research databases, including PubMed and Google Scholar, were searched for the last 20 years up to the date of inception, and nano toxicological aspects of these materials on male and female reproductive systems have been described in detail. Furthermore, a discussion has also been dedicated to the placental interaction of these nanoparticles and how these can cross the blood–placental barrier and precipitate nanotoxicity in the developing offspring. Fetal abnormalities as a consequence of the administration of nanoparticles and pathophysiological deviations and aberrations in the developing fetus have also been touched upon. A section has also been dedicated to the regulatory requirements and guidelines for the testing of nanoparticles for their safety and toxicity in reproductive systems. It is anticipated that this review will incite a considerable interest in the research community functioning in the domains of pharmaceutical formulations and development in nanomedicine-based designing of therapeutic paradigms.

Combined lead and zinc oxide-nanoparticles induced thyroid toxicity through 8-OHdG oxidative stress-mediated inflammation, apoptosis, and Nrf2 activation in rats

A human is exposed to a chemical mixture rather than a single chemical, particularly with the wide spread of nanomaterials. Therefore, the present study evaluated the combined exposure of lead acetate (Pb) and zinc oxide-nanoparticles (ZnO-NPs) compared to each metal alone on the thyroid gland of adult rats. A total of 30 adult male albino rats were divided into four groups, group I (control), group II received Pb (10 mg/kg), group III received ZnO-NPs (85 mg/kg) and group IV co-administrated the two metals in the same previous doses. The materials were gavaged for 8 weeks. The toxicity was assessed through several biochemical parameters. Our results revealed significant body weight reduction relative to increased thyroid weights, decreased both of serum-free triiodothyronine (FT3), tetra-iodothyronine (FT4), increased thyroid-stimulating hormone (TSH), increased serum and thyroid levels of Pb and zinc, significant elevation in tumor necrosis factor-α (TNF-α), reduction in interleukin 4 (IL4), upregulation of Bax, and downregulation of Bcl-2 genes. Additionally, there was significant overexpression of nuclear factor erythroid 2-related factor 2(Nrf2), 8-Hydroxydeoxyguanosine(8-OHdG), the elevation of tissues malondialdehyde (MDA), reduction of tissues total antioxidant capacity (TAC), and disruptive thyroid structural alterations in all metals groups with marked changes in the combined metals group. In conclusion, the combined exposure of Pb and ZnO-NPs induced pronounced toxic thyroid injury, pointing to additive effects in rats than the individual metal effects through different significant changes of disruptive thyroid structural alterations related to the loading of thyroid tissues with Pb and zinc metals producing oxidative stress that mediated inflammation and apoptosis.

Toxicity mechanisms of nanoparticles in the male reproductive system

The field of nanotechnology has allowed for increasing nanoparticle (NP) exposure to the male reproductive system. Certain NPs have been reported to have adverse consequences on male germ and somatic cells. Germ cells are the bridge between generations and are responsible for the transmission of genetic and epigenetic information to future generations. A number of NPs have negative impacts on male germ and somatic cells which could ultimately affect fertility or the ability to produce healthy offspring. These impacts are related to NP composition, modification, concentration, agglomeration, and route of administration. NPs can induce severe toxic effects on the male reproduction system after passing through the blood-testis barrier and ultimately damaging the spermatozoa. Therefore, understanding the impacts of NPs on reproduction is necessary. This review will provide a comprehensive overview on the current state of knowledge derived from the previous in vivo and in vitro research on effects of NPs on the male reproductive system at the genetic, cellular, and molecular levels.

Hierarchical Gold Mesoflowers in Enzyme Engineering: An Environmentally Friendly Strategy for the Enhanced Enzymatic Performance and Biodiesel Production

To expand the field of nanomaterial and engineering of enzyme in eco-friendly processes, gold mesoflower (Au-MF) nanostructure was applied for preparation of three series of immobilized lipase (Au-MF/SAM 1-3) through biofunctionalization of surface by Ugi multicomponent reaction. The synthesized Au-MF/SAM 1-3/lipase as unique biocatalysts was confirmed by different analytical tools and techniques. Compared to the free lipase, the Au-MF/SAM 1-3/lipase showed more stability at high temperature and pH. Also, these biocatalysts showed high storage stability and reusability after 2 months and eight cycles, respectively. Moreover, the kinetic behavior was investigated and the results showed a minimal impairment of catalytic activity of immobilized lipase. The kinetic constants of the immobilized lipase, Au-MF/SAM 2/lipase, are K_m = 0.37 mM, V_max = 0.22 mM min^-1, and k_cat = 154 min^-1. The immobilized lipase showed smaller activation energy (E_a) than that of free enzyme, indicating that the immobilized enzyme is less sensitive to temperature. In the following, the biodiesel production from palmitic acid was studied in the presence of Au-MF/SAM 2/lipase as an efficient biocatalyst. The influence of different reaction parameters such as temperature, molar ratio of alcohol to palmitic acid, water content, and lipase amount was deeply investigated.

Ameliorating effects of curcumin-loaded superparamagnetic iron oxide nanoparticles (SPIONs) on the mouse testis exposed to the transient hyperthermia: A molecular and stereological study

BACKGROUND

Testicular hyperthermia can have negative effects on male fertility. Despite reported therapeutic benefits of curcumin, several factors often limit its application such as low water solubility and instable structure. Curcumin-loaded superparamagnetic iron oxide nanoparticles (SPIONs) were designed to solve its limitation of use. In the present study, we evaluated the effect of curcumin-loaded SPIONs on transient testicular hyperthermia in mouse.

MATERIALS AND METHOD

A total of 18 adult male NMRI mice were divided into three groups (n = 6): I. Controls (Cont), II. Scrotal hyperthermia (Hyp), III. Scrotal hyperthermia + curcumin-loaded iron particles (240 μL) (Hyp + Cur). After seventy days, the animals were sacrificed and used for further molecular and stereological evaluations.

RESULTS

Sperm count, motility and viability significantly decreased in group hyp as compared to cont group. Furthermore, Sperm DNA fragmentation and cell apoptosis in testes increased remarkably in group hyp, compared with group cont. Stereological study showed a reduction in number of spermatogenic and Leydig cells, as well as reduced weight and volume of testes in hyp group. Degenerative appearance of testes exposed to hyperthermia was also observed. In addition, higher mRNA expression of inflammatory cytokines (IL1-α, IL6, and TNF-α) was detected in group hyp compared to cont group. However, curcumin-loaded SPIONs alleviated all of the pathologic changes in the Hyp + Cur group compared to the hyp group.

CONCLUSION

Here, we used nanoparticle form of curcumin in testicular hyperthermia model and showed its ameliorating effects on testes damages caused by heat stress, which can be an appropriate method to overcome the problems that limit curcumin application in cases with increased intra testicular temperature.

Non-viral transfection vectors: are hybrid materials the way forward?

Transfection is a process by which oligonucleotides (DNA or RNA) are delivered into living cells. This allows the synthesis of target proteins as well as their inhibition (gene silencing). However, oligonucleotides cannot cross the plasma membrane by themselves; therefore, efficient carriers are needed for successful gene delivery. Recombinant viruses are among the earliest described vectors. Unfortunately, they have severe drawbacks such as toxicity and immunogenicity. In this regard, the development of non-viral transfection vectors has attracted increasing interests, and has become an important field of research. In the first part of this review we start with a tutorial introduction into the biological backgrounds of gene transfection followed by the classical non-viral vectors (cationic organic carriers and inorganic nanoparticles). In the second part we highlight selected recent reports, which demonstrate that hybrid vectors that combine key features of classical carriers are a remarkable strategy to address the current challenges in gene delivery.

Genotoxicity evaluation of zinc oxide nanoparticles in Swiss mice after oral administration using chromosomal aberration, micronuclei, semen analysis, and RAPD profile

The expanded uses of zinc oxide nanoparticles (ZnO NPs) have grown rapidly in the field of nanotechnology. Thus, rising production of nanoparticles (NPs) increases the possible risks to the environment and occupationally exposed humans. Hence, it is indispensable to appraise the safety toxicity including genotoxicity for these NPs. In the present study, we have evaluated the genotoxic effect of ZnO NPs after oral administration to Swiss mice at dose levels of 300 and 2000 mg/kg body weight. These doses were administered for 2 days at 24 h apart. Chromosomal aberration (CA) and micronucleus tests were conducted following Organization for Economic Co-operation and Development guidelines. DNA damage was evaluated at 0, 24, 48, and 72 h posttreatment using a randomly amplified polymorphic DNA (RAPD) assay; additionally, semen analyses were also performed at 34.5 days post oral exposure. The reactive oxygen species (ROS), 8-oxo-2'-deoxyguanosine and CAs were increased ( p < 0.05) at the highest dosage (2000 mg/kg) of ZnO NPs compared to controls. Aberrant sperm morphology with reduced sperm count and motility were also present ( p < 0.05) in the high-dose group. Based on the RAPD assay, the genomic template stability within the high-dose group (<90%) was less than the controls (100%). The results suggested that ZnO NPs are mildly genotoxic in a dose-related manner and this toxicity were induced by generation of ROS.

Toxicity of Nanoparticles on the Reproductive System in Animal Models: A Review

In the last two decades, nanotechnologies demonstrated various applications in different fields, including detection, sensing, catalysis, electronics, and biomedical sciences. However, public concerns regarding the well-being of human may hinder the wide utilization of this promising innovation. Although, humans are exposed to airborne nanosized particles from an early age, exposure to such particles has risen dramatically within the last century due to anthropogenic sources of nanoparticles. The wide application of nanomaterials in industry, consumer products, and medicine has raised concerns regarding the potential toxicity of nanoparticles in humans. In this review, the effects of nanomaterials on the reproductive system in animal models are discussed. Females are particularly more vulnerable to nanoparticle toxicity, and toxicity in this population may affect reproductivity and fetal development. Moreover, various types of nanoparticles have negative impacts on male germ cells, fetal development, and the female reproductive system. These impacts are associated with nanoparticle modification, composition, concentration, route of administration, and the species of the animal. Therefore, understanding the impacts of nanoparticles on animal growth and reproduction is essential. Many studies have examined the effects of nanoparticles on primary and secondary target organs, with a concentration on the in vivo and in vitro effects of nanoparticles on the male and female reproductive systems at the clinical, cellular, and molecular levels. This review provides important information regarding organism safety and the potential hazards of nanoparticle use and supports the application of nanotechnologies by minimizing the adverse effects of nanoparticles in vulnerable populations.

Toward Chemical Perfection of Graphene-Based Gene Carrier via Ugi Multicomponent Assembly Process

The graphene-based materials with unique, versatile, and tunable properties have brought new opportunities for the leading edge of advanced nanobiotechnology. In this regard, the use of graphene in gene delivery applications is still at early stages. In this study, we successfully designed a new complex of carboxylated-graphene (G-COOH) with ethidium bromide (EtBr) and used it as a nanovector for efficient gene delivery into the AGS cells. G-COOH, with carboxyl functions on its surface, in the presence of EtBr, formaldehyde, and cyclohexylisocyanide were participated in Ugi four component reaction to fabricate a stable amphiphilic graphene-EtBr (AG-EtBr) composite. The coupling reaction was confirmed by further analyses with FT-IR, AFM, UV-vis, Raman, photoluminescence, EDS, and XPS. The AG-EtBr nanocomposite was able to interact with a plasmid DNA (pDNA). This nanocomposite has been applied for transfection of cultured mammalian cells successfully. Moreover, the AG-EtBr composites showed a remarkable decreased cytotoxicity in compared to EtBr. Interestingly, the advantages of AG-EtBr in cell transfection are more dramatic (3-fold higher) than Lipofectamine2000 as a commercial nonviral vector. To the best of our knowledge, this is the first report in which EtBr is used as an intercalating agent along with graphene to serve as a new vehicle for gene delivery application.

Cytotoxic and genotoxic effects of titanium dioxide nanoparticles in testicular cells of male wistar rat

Serious concerns have been expressed about potential risks of engineered nanoparticles. Regulatory health risk assessment of such particles has become mandatory for the safe use in consumer products and medicines; also, the potential effects on reproduction and fertility are relevant for this risk evaluation. In the present study, we examined the effects of intravenously injected titanium dioxide nanoparticles (TiO2-NPs; 21 nm), with special emphasis on reproductive system. Antioxidant enzymes such as catalase, glutathione peroxidase, and superoxide dismutase showed a significant decrease, while significant increase in lipid peroxidase was observed. Our results confirmed the bioaccumulation of TiO2-NPs in testicular cells. In TiO2-NPs-treated animals, various functional and pathological disorders, such as reduced sperm count, increase in caspase-3 (a biomarker of apoptosis), creatine kinase activity, DNA damage, and cell apoptosis were observed. Moreover, the testosterone activity was decreased significantly in a dose-dependent manner in the animals treated with TiO2-NPs as compared with control group animals. It is concluded that TiO2-NPs induce oxidative stress, which produce cytotoxic and genotoxic changes in sperms which may affect the fertilizing potential of spermatozoa.

Effect of beta-carotene on titanium oxide nanoparticles-induced testicular toxicity in mice

OBJECTIVE

This study evaluated the protective effect of beta-carotene (BC) on titanium oxide nanoparticle (TNP) induced spermatogenesis defects in mice.

MATERIALS AND METHODS

Thirty-two NMRI mice were randomly divided into four groups. BC group received 10 mg/kg of BC for 35 days. TNP group received 300 mg/kg TNP for 35 days. TNP+BC group initially received 10 mg/kg BC for 10 days and was followed by concomitant administration of 300 mg/kg TNP for 35 days. Control group received only normal saline for 35 days. Epididymal sperm parameters, testicular histopathology, spermatogenesis assessments and testosterone assay were performed for evaluation of the TNP and BC effects on testis.

RESULTS

Serum testosterone levels were markedly decreased in TNP-intoxicated mice. Epididymal sperm parameters including sperm number, motility and percentage of abnormality were significantly changed in TNP-intoxicated mice (p < 0.01). Histopathological criteria such as epithelial vacuolization, sloughing of germ cells and detachment were significantly increased in TNP-intoxicated mice (p < 0.001). BC+TNP treatment significantly prevented these changes (p < 0.05). BC also significantly elevates testosterone levels in BC+TNP group compared to TNP-treated mice (p < 0.01).

DISCUSSION AND CONCLUSION

The results of this study demonstrated that BC improved the spermatogenesis defects in TNP-treated mice. BC had a potent protective effect against the testicular toxicity and might be clinically useful.

The effect of zinc oxide nanoparticles on mouse spermatogenesis

OBJECTIVE

To evaluate the effects of zinc oxide nanoparticles on mouse spermatogenesis.

METHODS

Thirty two adult male NMRI mice were used. Experimental Groups (ZNP-1-ZNP-3) received one of the following treatments daily for 35 days: 5, 50 and 300 mg/kg zinc oxide nanoparticles respectively. Control group received only distilled water. Epididymal sperm parameters, testicular histopathology, morphometric analysis and spermatogenesis assessments were performed for evaluation of the zinc oxide nanoparticles effects on testis.

RESULTS

Epididymal sperm parameters including sperm number, motility and percentage of abnormality were significantly changed in 50 and 300 mg/kg zinc oxide nanoparticles treated mice (p < 0.01). Histopathological criteria such as epithelial vacuolization, sloughing of germ and detachment were significantly increased in 50 and 300 mg/kg zinc oxide nanoparticles treated mice (p < 0.001). 300 mg/kg zinc oxide nanoparticles induced formation of multinucleated giant cells in the germinal epithelium. 50 and 300 mg/kg zinc oxide nanoparticles also caused a significant decrease in seminiferous tubule diameter, seminiferous epithelium height and maturation arrest (p < 0.001).

CONCLUSION

Zinc oxide nanoparticles act as testicular toxicant and further studies are needed to establish its mechanism of action upon spermatogenesis.

In vitro effect of gold and silver nanoparticles on human spermatozoa

The cytotoxicity of Au/Ag nanoparticles (NPs) on human spermatozoa was investigated in vitro. Semen from donors were incubated (37 °C, 60'-120') with 30, 60, 125, 250 and 500 μM Au/Ag-NPs. Sperm motility was evaluated following WHO guidelines; sperm viability was assessed with eosin Y test. Au-NPs were characterised and localised with field emission gun-based scanning transmission electron microscope/energy dispersive spectroscopy and transmission electron microscopy. Both tested NPs exerted a significant dose-dependent effect on motility and viability of human spermatozoa (P < 0.001). Ag-NPs seem to show a slightly elevated toxicity although not significant (P > 0.05). Au-NPs were localised in spermatozoa, whereas Ag-NPs were undetectable. In conclusion, Au-NPs and Ag-NPs do not appear to be harmful for human spermatozoa up to high concentrations (250-500 μM) that are probably difficult to reach in vivo. It is mandatory to explore the genotoxic effect of NPs in germ cells.

Nanoparticle-mediated local delivery of an antisense TGF-β1 construct inhibits intimal hyperplasia in autogenous vein grafts in rats

Background

Intimal hyperplasia is one of the most important causes of vascular graft failure. Numerous studies have correlated transforming growth factor-β1 (TGF-β1) with extracellular matrix (ECM) deposition, a hallmark of intimal thickening.

Principal Findings

In the present study, we performed immunohistochemistry, RT-PCR, and Western blot to examine the dynamic expression of TGF-β1, TGF-β1 receptor type I (TGF-β RI), matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) during intimal hyperplasia in grafted veins of a rat model generated by grafting a portion of the right internal jugular vein to the ipisiliary caroid artery. Additionally, we determined whether nanoparticle-mediated delivery of a TGF-β1 antisense-expressing construct prevented TGF-β1 expression and intimal hyperplasia in grafted veins. In grafted veins, the expression of TGF-β1 significantly increased on day 3 after transplantation, peaked on day 7, slightly decreased on day 14, and returned to baseline levels on day 28. The positive expression of TGF-β RI in grafted veins remarkably increased on day 7, peaked on day 14, and decreased thereafter. MMP-1 expression decreased significantly, while TIMP-1 expression increased, significantly on days 14 and 28. Nanoparticle-mediated delivery of a TGF-β1 antisense-expressing construct down-regulated TGF-β1 expression and inhibited intimal hyperplasia in grafted veins.

Conclusions

Our findings provide further evidence that TGF-β1 plays an integral role in the development of intimal hyperplasia after vascular injury. Nanoparticle-mediated delivery of a TGF-β1 antisense-expressing construct is a feasible strategy to target TGF-β1-induced intimal thickening.

Progress and outlook of inorganic nanoparticles for delivery of nucleic acid sequences related to orthopedic pathologies: a review

The anticipated growth in the aging population will drastically increase medical needs of society; of which, one of the largest components will undoubtedly be from orthopedic-related pathologies. There are several proposed solutions being investigated to cost-effectively prepare for the future--pharmaceuticals, implant devices, cell and gene therapies, or some combination thereof. Gene therapy is one of the more promising possibilities because it seeks to correct the root of the problem, thereby minimizing treatment duration and cost. Currently, viral vectors have shown the highest efficacies, but immunological concerns remain. Nonviral methods show reduced immune responses but are regarded as less efficient. The nonviral paradigms consist of mechanical and chemical approaches. While organic-based materials have been used more frequently in particle-based methods, inorganic materials capable of delivery have distinct advantages, especially advantageous in orthopedic applications. The inorganic gene therapy field is highly interdisciplinary in nature, and requires assimilation of knowledge across the broad fields of cell biology, biochemistry, molecular genetics, materials science, and clinical medicine. This review provides an overview of the role each area plays in orthopedic gene therapy as well as possible future directions for the field.

FUNCTIONAL NANOPARTICLES FOR MOLECULAR IMAGING GUIDED GENE DELIVERY

Gene therapy has great potential to bring tremendous changes in treatment of various diseases and disorders. However, one of the impediments to successful gene therapy is the inefficient delivery of genes to target tissues and the inability to monitor delivery of genes and therapeutic responses at the targeted site. The emergence of molecular imaging strategies has been pivotal in optimizing gene therapy; since it can allow us to evaluate the effectiveness of gene delivery noninvasively and spatiotemporally. Due to the unique physiochemical properties of nanomaterials, numerous functional nanoparticles show promise in accomplishing gene delivery with the necessary feature of visualizing the delivery. In this review, recent developments of nanoparticles for molecular imaging guided gene delivery are summarized.

Novel amino-modified silica nanoparticles as efficient vector for hepatocellular carcinoma gene therapy

Due to the ineffective conventional treatment for hepatocellular carcinoma (HCC), the nonviral gene delivery system has been proved to be an attractive alternative to HCC therapy. In this work, we have developed a kind of new self-assembled nanoparticles, which were named as amino-modified silica nanoparticles (AMSNs). Scanning electron microscopy and zeta potential results demonstrated that AMSNs had a diameter of 20-30 nm and positive surface charges of +11.3 mV, respectively. The AMSNs could bind DNA strongly and protect DNA from degradation, which was confirmed by DNA-binding assay and serum protection assay. Furthermore, AMSNs could transfer foreign DNA into targeted cells with high transfection efficiency and little cytotoxicity. Combined with the p53 gene, AMSNs could transfect pp53-EGFP in HepG2 cells and result in a high-level of p53 mRNA and protein expressions. The nude mice treated with AMSNs/pp53-EGFP complexes showed significant tumor growth inhibition. Our results showed the AMSNs, an efficient gene vector, had the potential of gene therapy for HCC.

Gold nanoparticles enter rat ovarian granulosa cells and subcellular organelles, and alter in-vitro estrogen accumulation

Nanoparticle technology refers to research and technology developed at the atomic or molecular level for materials of approximately 1-100 nm in length. Through accidental or involuntary exposure, nanoparticles are potentially toxic to the body, including reproductive organs. Ovarian granulosa cells play a major role in maintaining ovarian function, health, and female fertility. Since these cells are involved in steroidogenesis, we wished to evaluate whether nanoparticles affected them after traversing their membranes. Cells were co-incubated with 10 nm gold particles for up to 24 h. Transmission electron micrographs were taken of GC treated with 10 nm gold particles in order to compare and contrast ultrastructural locations of nanoparticles with treatment. From micrograph comparisons of treated vs. untreated GC at various culture times, it appeared that some intracellular organelles involved in steroidogenesis were infiltrated and/or altered due to the presence of the nanogold particles. Medium samples were taken in order to determine estradiol-17beta (E2) accumulation/secretion by untreated vs. treated cells. GC incubated with 10 nm nanogold particles for 1, 3, or 5 h were found to accumulate significantly increased amounts of estrogen compared with untreated cells. Conversely, at 24 h there was a significant attenuation with respect to controls. The data presented here provide insight into the toxicologic effects gold nanoparticles elicit on ovarian granulosa cells.

The status of in vitro toxicity studies in the risk assessment of nanomaterials

Nanotechnology applications already on the market or in development promise great benefits for humans as well as the environment. Simultaneously, the pressure to advance the development of fast methods for evaluating the potential risks of increased human exposure to nanomaterials is augmented. One way forward would be to enhance the role of in vitro toxicity studies in risk assessment procedures of nanomaterials. However, to maximize the use of in vitro assays for this purpose, their values and limitations need to be revealed. Even in risk assessment frameworks for regular chemicals, in vitro studies play a minor role. A comparative analysis of published in vitro data with nanomaterials demonstrates that there are a number of issues that need resolving before in vitro studies can play a role in the risk assessment of nanomaterials.

Inorganic nanoparticles as carriers of nucleic acids into cells

The transfer of nucleic acids (DNA or RNA) into living cells, that is, transfection, is a major technique in current biochemistry and molecular biology. This process permits the selective introduction of genetic material for protein synthesis as well as the selective inhibition of protein synthesis (antisense or gene silencing). As nucleic acids alone are not able to penetrate the cell wall, efficient carriers are needed. Besides viral, polymeric, and liposomal agents, inorganic nanoparticles are especially suitable for this purpose because they can be prepared and surface-functionalized in many different ways. Herein, the current state of the art is discussed from a chemical viewpoint. Advantages and disadvantages of the available methods are compared.

High-level expression, one-step purification of soluble Ad5-knob protein and its activity assay

This report describes a simple, highly efficient, and reproducible method for obtaining large quantities of highly pure recombinant Ad5-knob protein, which can be used for gene-delivery application. The Ad5- knob protein expressed in Escherichia coli contained a His tag at the N-terminus that allowed one-step isolation by immobilized metal affinity chromatography (IMAC). The activity of the recombinant protein was tested by receptor-binding assay in Hela cells for potential application in gene delivery.

Oops they did it again! Carbon nanotubes hoax scientists in viability assays

New materials of emerging technological importance are single-walled carbon nanotubes (SWCNTs). Because SWCNTs will be used in commercial products in huge amounts, their effects on human health and the environment have been addressed in several studies. Inhalation studies in vivo and submerse applications in vitro have been described with diverging results. Why some indicate a strong cytotoxicity and some do not is what we report on here. Data from A549 cells incubated with carbon nanotubes fake a strong cytotoxic effect within the MTT assay after 24 h that reaches roughly 50%, whereas the same treatment with SWCNTs, but detection with WST-1, reveals no cytotoxicity. LDH, FACS-assisted mitochondrial membrane potential determination, and Annexin-V/PI staining also reveal no cytotocicity. SWCNTs appear to interact with some tetrazolium salts such as MTT but not with others (such as WST-1, INT, XTT). This interference does not seem to affect the enzymatic reaction but lies rather in the insoluble nature of MTT-formazan. Our findings strongly suggest verifying cytotoxicity data with at least two or more independent test systems for this new class of materials (nanomaterials). Moreover, we intensely recommend standardizing nanotoxicological assays with regard to the material used: there is a clear need for reference materials. MTT-formazan crystals formed in the MTT reaction are lumped with nanotubes and offer a potential mechanism to guide bioremediation and clearance for SWCNTs from "contaminated" tissue. SWCNTs are good supporting materials for tissue growth, as attachment of focal adhesions and connections to the cytoskeleton suggest.

In vitro cytotoxicity of nanoparticles in mammalian germline stem cells

Gametogenesis is a complex biological process that is particularly sensitive to environmental insults such as chemicals. Many chemicals have a negative impact on the germline, either by directly affecting the germ cells, or indirectly through their action on the somatic nursing cells. Ultimately, these effects can inhibit fertility, and they may have negative consequences for the development of the offspring. Recently, nanomaterials such as nanotubes, nanowires, fullerene derivatives (buckyballs), and quantum dots have received enormous national attention in the creation of new types of analytical tools for biotechnology and the life sciences. Despite the wide application of nanomaterials, there is a serious lack of information concerning their impact on human health and the environment. Thus, there are limited studies available on toxicity of nanoparticles for risk assessment of nanomaterials. The purpose of this study was to assess the suitability of a mouse spermatogonial stem cell line as a model to assess nanotoxicity in the male germline in vitro. The effects of different types of nanoparticles on these cells were evaluated by light microscopy, and by cell proliferation and standard cytotoxicity assays. Our results demonstrate a concentration-dependent toxicity for all types of particles tested, whereas the corresponding soluble salts had no significant effect. Silver nanoparticles were the most toxic while molybdenum trioxide (MoO(3)) nanoparticles were the least toxic. Our results suggest that this cell line provides a valuable model with which to assess the cytotoxicity of nanoparticles in the germ line in vitro.

Calcium phosphate nanoparticles as a novel nonviral vector for efficient transfection of DNA in cancer gene therapy

To explore an efficient gene vector in cancer gene therapy, a novel nonviral vector calcium phosphate nanoparticle (CPNP) was developed. Transmission electromicroscopy and Zeta potential demonstrated that CPNP was 23.5-34.5 nm diameters and had +16.8 mV positive surface charges. The analysis of the CPNPDNA complex showed CPNP could transfer foreign DNA into targeted cells with high transfection efficiency, as well as its DNA-binding property and protection of DNA from degradation. Furthermore, the CPNP-DNA complex had no obvious cytotoxicity for CNE-2 cells, while the liposome-DNA complex had certain cytotoxicity. When the CPNP combined with suicide genes yCDglyTK for nasopharyngeal carcinoma (NPC) therapy in vitro, just 24.76% of cells survived when the wild-type CNE-2 cells were treated with the CPNP-yCDglyTK complex plus the prodrug, 5-FC (200 mg/mL). Otherwise, the expression of yCDglyTK was detected in implanted CNE-2 tumors by reverse transcription-polymerase chain reaction (RT-PCR) analysis when the CNE-2 tumor was treated with an intratumoral injection of the CPNPyCDglyTK complex. Our results showed that the CPNP might be a potential vector for gene therapy.

A novel fusion suicide gene yeast CDglyTK plays a role in radio-gene therapy of nasopharyngeal carcinoma

To investigate a novel suicide gene for nasopharyngeal carcinoma (NPC) therapy, the yCDglyTK gene was constructed by fusing yeast cytosine deaminase (CD) and herpes simplex type 1 thymidine kinase. The expression of the yCDglyTK gene was detected by RT-PCR and Western blotting, and its bioactivity was demonstrated by an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. An animal study was carried out in which BALB/C nude mice bearing yCDglyTK gene-modified tumors were treated with prodrugs and radiation. Our results revealed that the yCDglyTK gene could be expressed in CNE-2 cells in vitro. In MTT analysis, at the transfection rate of 10%, 66% cells were killed. The synergistic effect of CD and TK showed 91% of yCDglyTK-transfected cells were killed with the treatment of 5-fluorocytosine (5-FC) alone, 60% killed with ganciclovir (GCV) alone, and 75% killed with 5-FC and GCV together. In vivo, the tumor volume in all of the four prodrugs and/or radiation-treated groups were significantly different from that in the PBS-controlled group (P<.01); also yCDglyTK+prodrug+radiation group was different from the other three groups (P<.05). Our findings suggested there was a synergistic antitumor effect when combining suicide gene therapy and radiation, and yCDglyTK has potent antitumor efficacy and may be a candidate suicide gene for cancer therapy.

pDNA loaded calcium phosphate nanoparticles: highly efficient non-viral vector for gene delivery

Nanoparticles of calcium phosphate encapsulating plasmid DNA (pDNA) of size 100-120 nm in diameter were prepared. XRD studies of these nanoparticles showed them to be crystalline in nature having hydroxyapatite structure. The maximum loading of pDNA and its release from nanoparticles were studied using gel electrophoresis. The time dependent size measurement of these particles demonstrated that these particles show strong aggregational behaviour in aqueous dispersion. Calcium phosphate nanoparticles were found to be dissolved even in low acidic buffer (pH 5.0) releasing the pDNA, which suggested that DNA release from these particles in the endosomal compartment was possible. In vitro transfection efficiency of these calcium phosphate nanoparticles was found to be higher than that of the commercial transfecting reagent Polyfect.

The combination of suicide gene therapy and radiation enhances the killing of nasopharyngeal carcinoma xenographs

Nasopharyngeal carcinoma (NPC) is very common in Southern China and Southeast Asian countries. To explore a novel and more effective approach to NPC therapy, a combined strategy of suicide genes and radiation was designed in this study. Five suicide gene expression cassettes, yeast CD, yeast CD/UPRT, and yeast CDglyTK gene controlled by CMV, and Egr-1 and a synthetic CMV-enhanced Egr-1 promoter (CE) were constructed in an expression vector p11MS. The expression of suicide genes in NPC CNE-2 cells were detected by RT-PCR and Western blot. The cytotoxicity of suicide gene therapy and radiation were analyzed by MTT assay. An animal study in which yeast CD/UPRT-expressing CNE-2 tumors in nude mice were treated with 5-FC and radiation was also developed. Our results revealed that p11MSCEyCD/UPRT and p11MSCEyCDglyTK are superior over three other constructs in the killing of NPC cells in vitro. We combined suicide gene-expressing tumors, 5-FC treatment, and radiation in vivo and found that the tumors greatly regressed, some disappeared completely in 3 nude mice in the yCD/UPRT group, and a significant difference of tumor volumes was observed between this group and the other four groups (p < 0.05). Our results indicated that suicide gene therapy and radiation have a synergic effect on NPC therapy, and the combined strategy of radiogene therapy is of great potential as a substitute for the traditional method, radiation alone, in NPC therapies.

A Biphasic Response to Silica

Inhalation of crystalline silica may lead to acute or chronic silicosis. Although chronic silicosis is associated with increased incidence/exacerbation of autoimmune disorders, the immunologic effects of chronic silicosis are not completely understood. In an animal model of chronic silicosis, Lewis rats were exposed to filtered air or silica (1.75 microm average particle size) at an exposure concentration of 6.2 mg/m(3), 6 h/d, 5 d/wk for 6 wk, and observed up to 27 wk after the exposure. Based on silica burden, lung histopathology, and immunologic changes, two distinct stages were identified in the development of chronic silicosis. Stage 1 (4-28 d after exposure) was characterized by silica deposition in various tissues, and augmented antibody and cellular immunity. Although bronchoalveolar lavage contained an increased number of activated macrophages, protein and lactate dehydrogenase levels were comparable to controls. In Stage 2 (>/= 10 wk), silica was localized in epithelioid macrophages, and T cell immunity had returned to normal, but the lavage fluids contained increased protein concentration and lactate dehydrogenase activity. Moreover, lungs from silica-treated animals contained neutrophils and lymphocytes, and exhibited granulomatous changes around the silica-containing epithelioid macrophages. Thus, in the early stages of silicosis, silica activates the immune system; however, the progression of lung granulomas does not depend on a continually activated adaptive immune system.