Carbon nanofibers and carbon nanotubes sensitize prostate and bladder cancer cells to platinum-based chemotherapeutics

The emerging role and mechanism of HMGA2 in breast cancer

High mobility group AT-hook 2 (HMGA2) is a member of the non-histone chromosomal high mobility group (HMG) protein family, which participate in embryonic development and other biological processes. HMGA2 overexpression is associated with breast cancer (BC) cell growth, proliferation, metastasis, and drug resistance. Furthermore, HMGA2 expression is positively associated with poor prognosis of patients with BC, and inhibiting HMGA2 signaling can stimulate BC cell progression and metastasis. In this review, we focus on HMGA2 expression changes in BC tissues and multiple BC cell lines. Wnt/β-catenin, STAT3, CNN6, and TRAIL-R2 proteins are upstream mediators of HMGA2 that can induce BC invasion and metastasis. Moreover, microRNAs (miRNAs) can suppress BC cell growth, invasion, and metastasis by inhibiting HMGA2 expression. Furthermore, long noncoding RNAs (LncRNAs) and circular RNAs (CircRNAs) mainly regulate HMGA2 mRNA and protein expression levels by sponging miRNAs, thereby promoting BC development. Additionally, certain small molecule inhibitors can suppress BC drug resistance by reducing HMGA2 expression. Finally, we summarize findings demonstrating that HMGA2 siRNA and HMGA2 siRNA-loaded nanoliposomes can suppress BC progression and metastasis.

Gelatin-Functionalized Carbon Nanotubes Loaded with Cisplatin for Anti-Cancer Therapy

Cisplatin (Cp), a chemotherapeutic agent, interacts with purines on tumor DNA, causing tumor cell apoptosis. However, cisplatin has the characteristics of non-specific distribution and lack of selectivity, resulting in systemic toxicity. Moreover, it cannot maintain the drug's high concentration in the tumor-weak acid environment. These flaws of cisplatin restrict its use in clinical applications. Therefore, a pH-responsive carbon nanotube-modified nano-drug delivery system (CNTs/Gel/Cp) was constructed in this study using gelatin (Gel)-modified carbon nanotubes (CNTs/Gel) loaded with cisplatin to release drugs precisely and slowly, preventing premature inactivation and maintaining an effective concentration. When MCp:MCNTs/Gel = 1:1, the drug reaches the highest loading rate and entrapment efficiency. To achieve the sustained-release effect, CNTs/Gel/Cp can release the medicine steadily for a long time in a pH environment of 6.0. Additionally, CNTs/Gel/Cp display antitumor properties comparable to cisplatin in a manner that varies with the dosage administered. These findings indicate that CNTs/Gel/Cp have an effective, sustained release of cisplatin and a good antitumor effect, providing a theoretical and experimental basis for the clinical application of modified carbon nanotubes (CNTs) as a new drug delivery system.

Carbon Nanofiber-Sodium Alginate Composite Aerogels Loaded with Vitamin D: The Cytotoxic and Apoptotic Effects on Colon Cancer Cells

Colorectal cancer (CRC) is the fourth most commonly diagnosed cancer and the third leading cause of cancer-related deaths worldwide. A substantial body of literature supports the crucial role of vitamin D (VD) in the etiology, progression, prognosis, and treatment of cancer. Recent clinical studies have found an inverse correlation between CRC incidence and serum VD levels. However, the low water solubility of VD and its anticarcinogenic activity at supraphysiological plasma levels, which causes hypercalcemia, required carrier systems. Carbon-based nanomaterials are excellent eco-friendly candidates, with exceptional chemical resistance, efficient mechanical properties, and negligible weight. Furthermore, composite aerogels manufactured from these nanomaterials have gained interest due to their extensive surface areas and porous structures, which make them suitable for delivering drugs. Our research aimed to study the development of composite aerogels loaded with VD by utilizing carbon nanofibers (CNFs) in an aerogel matrix provided to colon cancer cells. For this purpose, Aero1 as a drug delivery system was first prepared and characterized using XRD, FTIR, and SEM methods. Biochemical methods were employed to evaluate the antiproliferative, apoptotic, and anti-migratory effects on colon cancer cells. FTIR and XRD measurements confirmed the production of aerogels. SEM analysis revealed that aerogels have a non-uniform surface. The findings showed that aerogels can effectively deliver VD to the colon cancer cells, while also inhibiting cancer cell proliferation and migration. This research suggests that the Aero1 drug delivery system could be a valuable tool in the fight against colon cancer and other health issues.

Biomedical application of graphitic carbon nitrides: tissue depositionin vivo, induction of reactive oxygen species (ROS) and cell viability in tumor cells

The urgency for new materials in oncology is immediate. In this study we have developed the g-C₃N₄, a graphitic-like structure formed by periodically linked tris-s-triazine units. The g-C₃N₄has been synthesized by a simple and fast thermal process. XRD has shown the formation of the crystalline sheet with a compacted structure. The graphite-like structure and the functional groups have been shown by Raman and FTIR spectroscopy. TEM image and AFM revealed the porous composed of five or six C-N layers stacked. DRS and Photoluminescence analyses confirmed the structure with band gap of 2.87 eV and emission band at 448 nm in different wavelengths excitation conditions. The biological results showed inhibitory effect on cancer cell lines and non-toxic effect in normal cell lines. To the best of our knowledge, this is the first work demonstrating the cytotoxic effects of 2D g-C₃N₄in a cancer cell line, without any external or synergistic influence. The biodistribution/tissue accumulation showed that g-C₃N₄present a tendency to accumulation on the lung in the first 2 h, but after 24 h the profile of the biodistribution change and it is found mainly in the liver. Thus, 2D-g-C₃N₄showed great potential for the treatment of several cancer types.

Clinical therapies and nano drug delivery systems for urinary bladder cancer

Bladder cancer is the 10^th most commonly occurring malignancy worldwide with a 75% of 5-year survival rate, while it ranks 13^th among the deaths occurring due to cancer. The majority of bladder cancer cases are diagnosed at an early stage and 70% are of non-invasive grade. However, 70% of these cases develop chemoresistance and progress to the muscle invasive stage. Conventional chemotherapy treatments are unsuccessful in curbing chemoresistance, bladder cancer progression while having an adverse side effect, which is mainly due to off-target drug distribution. Therefore, new drug delivery strategies, new therapeutics and therapies or their combination are being explored to develop better treatments. In this regard, nanotechnology has shown promise in the targeted delivery of therapeutics to bladder cancer cells. This review discusses the recent discovery of new therapeutics (chemotherapeutics, immunotherapeutic, and gene therapies), recent developments in the delivery of therapeutics using nano drug delivery systems, and the combination treatments with FDA-approved therapies, i.e., hyperthermia and photodynamic therapy. We also discussed the potential of other novel drug delivery systems that are minimally explored in bladder cancer. Lastly, we discussed the clinical status of therapeutics and therapies for bladder cancer. Overall, this review can provide a summary of available treatments for bladder cancer, and also provide opportunities for further development of drug delivery systems for better management of bladder cancer.

A comprehensive review summarizing the recent biomedical applications of functionalized carbon nanofibers

Since the discovery and fabrication of carbon nanofibers (CNFs) over a decade ago, scientists foster to discover novel myriad potential applications for this material in both biomedicine and industry. The unique economic viability, mechanical, electrical, optical, thermal, and structural properties of CNFs led to their rapid emergence. CNFs become an artificial intelligence platform for different uses, including a wide range of biomedical applications. Furthermore, CNFs have exceptionally large surface areas that make them flexible for tailoring and functionalization on demand. This review highlights the recent progress and achievements of CNFs in a wide range of biomedical fields, including cancer therapy, biosensing, tissue engineering, and wound dressing. Besides the synthetic techniques of CNFs, their potential toxicity and limitations, as biomaterials in real clinical settings, will be presented. This review discusses CNF's future investigations in other biomedical fields, including gene delivery and bioimaging and CNFs risk assessment.

Mesoporous silica coated carbon nanofibers reduce embryotoxicity via ERK and JNK pathways

Carbon nanofibers (CNFs) have been implicated in biomedical applications, yet, they are still considered as a potential hazard. Conversely, mesoporous silica is a biocompatible compound that has been used in various biomedical applications. In this regard, we recently reported that CNFs induce significant toxicity on the early stage of embryogenesis in addition to the inhibition of its angiogenesis. Thus, we herein use mesoporous silica coating of CNFs (MCNFs) in order to explore their outcome on normal development and angiogenesis using avian embryos at 3 days and its chorioallantoic membrane (CAM) at 6 days of incubation. Our data show that mesoporous silica coating of CNFs significantly reduces embryotoxicity provoked by CNFs. However, MCNFs exhibit slight increase in angiogenesis inhibition in comparison with CNFs. Further investigation revealed that MCNFs slightly deregulate the expression patterns of key controller genes involved in cell proliferation, survival, angiogenesis, and apoptosis as compared to CNFs. We confirmed these data using avian primary normal embryonic fibroblast cells established in our lab. Regarding the molecular pathways, we found that MCNFs downregulate the expression of ERK1/ERK2, p-ERK1/ERK2 and JNK1/JNK2/JNK3, thus indicating a protective role of MCNFs via ERK and JNK pathways. Our data suggest that coating CNFs with a layer of mesoporous silica can overcome their toxicity making them suitable for use in biomedical applications. Nevertheless, further investigations are required to evaluate the effects of MCNFs and their mechanisms using different in vitro and in vivo models.

Recent trends in carbon nanotubes based prostate cancer therapy: A biomedical hybrid for diagnosis and treatment

At present treatment methods for cancer are limited, partially due to the solubility, poor cellular distribution of drug molecules and, the incapability of drugs to annoy the cellular barriers. Carbon nanotubes (CNTs) generally have excellent physio-chemical properties, which include high-level penetration into the cell membrane, high surface area and high capacity of drug loading by in circulating modification with bio-molecules, project them as an appropriate candidate to diagnose and deliver drugs to prostate cancer (PCa). Additionally, the chemically modified CNTs which have excellent 'Biosensing' properties therefore makes it easy for detecting PCa without fluorescent agent and thus targets the particular site of PCa and also, Drug delivery can accomplish a high efficacy, enhanced permeability with less toxic effects. While CNTs have been mainly engaged in cancer treatment, a few studies are focussed on the diagnosis and treatment of PCa. Here, we detailly reviewed the current progress of the CNTs based diagnosis and targeted drug delivery system for managing and curing PCa.

When polymers meet carbon nanostructures: expanding horizons in cancer therapy

The development of hybrid materials, which combine inorganic with organic materials, is receiving increasing attention by researchers. As a consequence of carbon nanostructures high chemical versatility, they exhibit enormous potential for new highly engineered multifunctional nanotherapeutic agents for cancer therapy. Whereas many groups are working on drug delivery systems for chemotherapy, the use of carbon nanohybrids for radiotherapy is rarely applied. Thus, nanotechnology offers a wide range of solutions to overcome the current obstacles of conventional chemo- and/or radiotherapies. Within this review, the structure and properties of carbon nanostructures (carbon nanotubes, nanographene oxide) functionalized preferentially with different types of polymers (synthetic, natural) are discussed. In short, synthesis approaches, toxicity investigations and anticancer efficacy of different carbon nanohybrids are described.

Nanotechnology, from quantum mechanical calculations up to drug delivery

There are several reasons why nanotechnology is currently considered as the leader among the most intensively developing research trends. Nanomatter often exhibits new properties, other than those of the morphology of a continuous solid. Also, new phenomena appear at the nanoscale, which are unknown in the case of microcrystalline objects. For this reason, nanomaterials have already found numerous applications that are described in this review. However, among intensively developed various branches of nanotechnology, nanomedicine and pharmacology stand out particularly, which opens new possibilities for the development of these disciplines, gives great hope for the creation of new drugs in which toxicological properties are reduced to a minimum, reduces the doses of medicines, offers targeted treatment and increases diagnostic possibilities. Nanotechnology is the source of a great revolution in medicine. It gives great hope for better and faster treatment of many diseases and gives hope for a better tomorrow. However, the creation of new "nanodrugs" requires a special understanding of the properties of nanoparticles. This article is a review work which determines and describes the way of creating new nanodrugs from ab initio calculations by docking and molecular dynamic applications up to a new medicinal product, as a proposal for the personalized medicine, in the early future.

Systematic evaluation of oligodeoxynucleotide binding and hybridization to modified multi-walled carbon nanotubes

BACKGROUND

In addition to conventional chemotherapeutics, nucleic acid-based therapeutics like antisense oligodeoxynucleotides (AS-ODN) represent a novel approach for the treatment of bladder cancer (BCa). An efficient delivery of AS-ODN to the urothelium and then into cancer cells might be achieved by the local application of multi-walled carbon nanotubes (MWCNT). In the present study, pristine MWCNT and MWCNT functionalized with hydrophilic moieties were synthesized and then investigated regarding their physicochemical characteristics, dispersibility, biocompatibility, cellular uptake and mucoadhesive properties. Finally, their binding capacity for AS-ODN via hybridization to carrier strand oligodeoxynucleotides (CS-ODN), which were either non-covalently adsorbed or covalently bound to the different MWCNT types, was evaluated.

RESULTS

Pristine MWCNT were successfully functionalized with hydrophilic moieties (MWCNT-OH, -COOH, -NH2, -SH), which led to an improved dispersibility and an enhanced dispersion stability. A viability assay revealed that MWCNT-OH, MWCNT-NH2 and MWCNT-SH were most biocompatible. All MWCNT were internalized by BCa cells, whereupon the highest uptake was observed for MWCNT-OH with 40% of the cells showing an engulfment. Furthermore, all types of MWCNT could adhere to the urothelium of explanted mouse bladders, but the amount of the covered urothelial area was with 2-7% rather low. As indicated by fluorescence measurements, it was possible to attach CS-ODN by adsorption and covalent binding to functionalized MWCNT. Adsorption of CS-ODN to pristine MWCNT, MWCNT-COOH and MWCNT-NH2 as well as covalent coupling to MWCNT-NH2 and MWCNT-SH resulted in the best binding capacity and stability. Subsequently, therapeutic AS-ODN could be hybridized to and reversibly released from the CS-ODN coupled via both strategies to the functionalized MWCNT. The release of AS-ODN at experimental conditions (80 °C, buffer) was most effective from CS-ODN adsorbed to MWCNT-OH and MWCNT-NH2 as well as from CS-ODN covalently attached to MWCNT-COOH, MWCNT-NH2 and MWCNT-SH. Furthermore, we could exemplarily demonstrate that AS-ODN could be released following hybridization to CS-ODN adsorbed to MWCNT-OH at physiological settings (37 °C, urine).

CONCLUSIONS

In conclusion, functionalized MWCNT might be used as nanotransporters in antisense therapy for the local treatment of BCa.

Carbon nanomaterials sensitize prostate cancer cells to docetaxel and mitomycin C via induction of apoptosis and inhibition of proliferation

We have previously shown that carbon nanofibers (CNFs) and carbon nanotubes (CNTs) can sensitize prostate cancer (PCa) cells to platinum-based chemotherapeutics. In order to further verify this concept and to avoid a bias, the present study investigates the chemosensitizing potential of CNFs and CNTs to the conventional chemotherapeutics docetaxel (DTX) and mitomycin C (MMC), which have different molecular structures and mechanisms of action than platinum-based chemotherapeutics. DU-145 PCa cells were treated with DTX and MMC alone or in combination with the carbon nanomaterials. The impact of the monotreatments and the combinatory treatments on cellular function was then systematically analyzed by using different experimental approaches (viability, short-term and long-term proliferation, cell death rate). DTX and MMC alone reduced the viability of PCa cells to 94% and 68%, respectively, whereas a combined treatment with CNFs led to less than 30% remaining viable cells. Up to 17- and 7-fold higher DTX and MMC concentrations were needed in order to evoke a similar inhibition of viability as mediated by the combinatory treatments. In contrast, the dose of platinum-based chemotherapeutics could only be reduced by up to 3-fold by combination with carbon nanomaterials. Furthermore, combinatory treatments with CNFs led mostly to an additive inhibition of short- and long-term proliferation compared to the individual treatments. Also, higher cell death rates were observed in combinatory treatments than in monotreatments, e.g., a combination of MMC and CNFs more than doubled the cell death rate mediated by apoptosis. Combinations with CNTs showed a similar, but less pronounced impact on cellular functions. In summary, carbon nanomaterials in combination with DTX and MMC evoked additive to partly synergistic anti-tumor effects. CNFs and CNTs possess the ability to sensitize cancer cells to a wide range of structurally diverse chemotherapeutics and thus represent an interesting option for the development of multimodal cancer therapies. Co-administration of chemotherapeutics with carbon nanomaterials could result in a reduction of the chemotherapeutic dosage and thus limit systemic side effects.

Characterization of different carbon nanotubes for the development of a mucoadhesive drug delivery system for intravesical treatment of bladder cancer

In order to increase the effectiveness of therapeutics for bladder carcinoma (BCa) treatment, alternative strategies for intravesical applications are needed. The use of carbon nanotubes (CNTs) as basis for a multifunctional drug transporter is a promising possibility to combine traditional chemotherapeutics with innovative therapeutic agents such as antisense oligodeoxynucleotides or small interfering RNA. In the current study four CNT types varying in length and diameter (CNT-1, CNT-2, CNT-3, CNT-4) were synthesized and then characterized with different spectroscopic techniques. Compared to the pristine CNT-1 and CNT-3, the shortened CNT-2 and CNT-4 exhibited more defects and lower aspect ratios. To analyze their mucoadhesive properties, CNTs were exposed to mouse bladders ex vivo by using Franz diffusion cells. All four tested CNT types were able to adhere to the urothelium with a mean covering area of 5-10%. In vitro studies on UM-UC-3 and EJ28 BCa cells were conducted to evaluate the toxic potential of these CNTs. Viability and cytotoxicity assays revealed that the shortened CNT-2 and CNT-4 induced stronger inhibitory effects on BCa cells than CNT-1 and CNT-3. In conclusion, CNT-1 and CNT-3 showed the most promising properties for further optimization of a multifunctional drug transporter.

Integrated traditional Chinese and western medicine modulator for overcoming the multidrug resistance with carbon nanotubes

GA/Dox/P-gp Ab-CNTs, integrated specific targeting, P-gp inhibitor and chemotherapeutic agent, could represent a promising modulator for overcoming tumor MDR.

Design real-time reversal of tumor multidrug resistance cleverly with shortened carbon nanotubes

Multidrug resistance (MDR) in tumors renders many currently available chemotherapeutic drugs ineffective. Research in nanobiotechnology-based therapeutic alternatives has provided innovative and promising strategies to overcome MDR. The aim of this study was to investigate whether the new strategy of a co-loaded reversal agent and chemotherapeutic drug with shortened carbon nanotubes (CNTs) would show useful effects on the real-time reversal of tumor MDR. CNTs were cut and purified via ultrasonication and oxidative acid treatment to optimize their length for drug-delivery vehicles, then verapamil (Ver) and doxorubicin (Dox) were co-loaded on shortened CNTs (denoted as Ver/Dox/shortened CNTs), which acted as a drug delivery system. The multidrug resistant leukemia K562/A02 cells were treated with the denoted Ver/Dox/shortened CNTs. The real-time reversal of tumor MDR were evaluated by flow cytometer, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, acridine orange/ethidium bromide staining, and Western blot analysis. In the same MDR tumor cells the new strategy of a co-loaded reversal agent and chemotherapeutic drug with CNTs could inhibit the function of P-glycoprotein in real-time by Ver as reversal agent, significantly increase the uptake of Dox, enhance the sensitivity of the MDR cancer cells to the chemotherapeutic agent, and induce apoptosis. It was therefore concluded that a co-loaded reversal agent and chemotherapeutic drug with shortened CNTs could have real-time reversal ability of MDR in tumors, which could represent a promising approach in cancer therapy.

Chemosensitizing effects of carbon-based nanomaterials in cancer cells: enhanced apoptosis and inhibition of proliferation as underlying mechanisms

Recent studies have shown that carbon nanomaterials such as carbon nanofibres (CNFs) and multi-walled carbon nanotubes (CNTs) can exert antitumor activities themselves and sensitize cancer cells to conventional chemotherapeutics such as carboplatin and cisplatin. In the present study, the chemosensitizing effect of CNFs and CNTs on cancer cells of urological origin was investigated regarding the underlying mechanisms. Prostate cancer (DU-145, PC-3) and bladder cancer (EJ28) cells were treated with carbon nanomaterials (CNFs, CNTs) and chemotherapeutics (carboplatin, cisplatin) alone as well as in combination for 24 h. Forty-eight(EJ28) or 72 h (DU-145, PC-3) after the end of treatment the effects on cellular proliferation,clonogenic survival, cell death rate and cell cycle distribution were evaluated. Depending on the cell line, simultaneous administration of chemotherapeutics and carbon nanomaterials produced an additional inhibition of cellular proliferation and clonogenic survival of up to 77% and 98%, respectively, compared to the inhibitory effects of the chemotherapeutics alone. These strongly enhanced antiproliferative effects were accompanied by an elevated cell death rate, which was predominantly mediated via apoptosis and not by necrosis. The antitumor effects of combinations with CNTs were less pronounced than those with CNFs. The enhanced effects of the combinatory treatments on cellular function were mostly of additive to partly synergistic nature. Furthermore, cell cycle analysis demonstrated an arrest at the G2/M phase mediated by a monotreatment with chemotherapeutics. Following combinatory treatments, mostly less than or nearly additive increases of cell fractions in the G2/M phase could be observed. In conclusion,the pronounced chemosensitizing effects of CNFs and CNTs were mediated by an enhanced apoptosis and inhibition of proliferation. The combination of carbon-based nanomaterials and conventional chemotherapeutics represents a novel approach in cancer therapy to bypass chemoresistance by minimizing the chemotherapeutic dosing.