Mitochondria-dependent apoptosis induced by nanoscale hydroxyapatite in human gastric cancer SGC-7901 cells

Recent advances in nano-based drug delivery systems for treatment of liver cancer

Liver cancer is one of the aggressive primary tumors as evident by high rate of incidence and mortality. Conventional treatments (e.g. chemotherapy) suffer from various drawbacks including wide drug distribution, low localized drug concentration, and severe off-site toxicity. Therefore, they cannot satisfy the mounting need for safe and efficient cancer therapeutics, and alternative novel strategies are needed. Nano-based drug delivery systems (NDDSs) are among these novel approaches that can improve the overall therapeutic outcomes. NDDSs are designed to encapsulate drug molecules and target them specifically to liver cancer. Thus, NDDSs can selectively deliver therapeutic agents to the tumor cells and avoid distribution to off-target sites which should improve the safety profile of the active agents. Nonetheless, NDDSs should be well designed, in terms of the preparing materials, nanocarriers structure, and the targeting strategy, in order to accomplish these objectives. This review discusses the latest advances of NDDSs for cancer therapy with emphasis on the aforementioned essential design components. The review also entails the challenges associated with the clinical translation of NDDSs, and the future perspectives towards next-generation NDDSs.

Nano-hydroxyapatite promotes cell apoptosis by co-activating endoplasmic reticulum stress and mitochondria damage to inhibit glioma growth

Despite a growing body of studies demonstrating the specific anti-tumor effect of nano-hydroxyapatite (n-HA), the underlying mechanism remained unclear. Endoplasmic reticulum (ER) and mitochondria are two key players in intracellular Ca2+ homeostasis and both require Ca2+ to participate. Moreover, the ER-mitochondria interplay coordinates the maintenance of cellular Ca2+ homeostasis to prevent any negative consequences from excess of Ca2+, hence there needs in-depth study of n-HA effect on them. In this study, we fabricated needle-like n-HA to investigate the anti-tumor effectiveness as well as the underlying mechanisms from cellular and molecular perspectives. Data from in vitro experiments indicated that the growth and invasion of glioma cells were obviously reduced with the aid of n-HA. It is interesting to note that the expression of ER stress biomarkers (GRP78, p-IRE1, p-PERK, PERK, and ATF6) were all upregulated after n-HA treatment, along with the activation of the pro-apoptotic transcription factor CHOP, showing that ER stress produced by n-HA triggered cell apoptosis. Moreover, the increased expression level of intracellular reactive oxygen species and the mitochondrial membrane depolarization, as well as the downstream cell apoptotic signaling activation, further demonstrated the pro-apoptotic roles of n-HA induced Ca2+ overload through inducing mitochondria damage. The in vivo data provided additional evidence that n-HA caused ER stress and mitochondria damage in cells and effectively restrain the growth of glioma tumors. Collectively, the work showed that n-HA co-activated intracellular ER stress and mitochondria damage are critical triggers for cancer cells apoptosis, offering fresh perspectives on ER-mitochondria targeted anti-tumor therapy.

Divergent Responses of Hydrophilic CdSe and CdSe@CdS Core-Shell Nanocrystals in Apoptosis and In Vitro Cancer Cell Imaging: A Comparative Analysis

With their distinctive core-shell design, core-shell nanocrystals have drawn interest in catalysis, medicinal research, and nanotechnology. These nanocrystals have a variety of characteristics and possible uses. The application of core-shell nanocrystals offers significant potential in increasing diagnostic and therapeutic approaches for cancer research in apoptosis and in vitro cancer cell imaging. In the present study, we investigated the fluorescence behavior of hydrophilic CdSe (core-only) and CdSe@CdS (core-shell) nanocrystals (NCs) and their potential in cancer cell imaging. The addition of a CdS coating to CdSe NCs increased the fluorescence intensity tenfold. The successful fabrication of core-shell CdSe@CdS nanocrystals was proven by a larger particle size (evaluated via DLS and TEM) and their XRD pattern and surface morphology compared to CdSe (core-only) NCs. When these NCs were used for bioimaging in MCF-7 and HEK-293 cell lines, they demonstrated excellent cellular uptake due to higher fluorescence intensity within cancerous cells than normal cells. Comparative cytotoxicity studies revealed that CdSe NCs were more toxic to all three cell lines (HEK-293, MCF-7, and HeLa) than CdSe@CdS core-shell structures. Furthermore, a decrease in mitochondrial membrane potential and intracellular ROS production supported NCs inducing oxidative stress, which led to apoptosis via the mitochondria-mediated pathway. Increased cytochrome c levels, regulation of pro-apoptotic gene expression (e.g., p53, Bax), and down-regulation of Bcl-2 all suggested cellular apoptosis occurred via the intrinsic pathway. Significantly, at an equivalent dose of core-shell NCs, core-only NCs induced more oxidative stress, resulting in increased apoptosis. These findings shed light on the role of a CdS surface coating in reducing free radical release, decreasing cytotoxicity, and improving fluorescence, advancing the field of cell imaging.

The Cytotoxicity of Carbon Nanotubes and Hydroxyapatite, and Graphene and Hydroxyapatite Nanocomposites against Breast Cancer Cells

Cancer is a current dreadful disease and the leading cause of death. Next to cardiovascular diseases, cancer is the most severe threat to human life and health. Breast cancer is the most common invasive cancer diagnosed in women. Each year about 2.3 million women are diagnosed with breast cancer. In consideration of the severity of breast cancer, herein we designed the biocompatible nanomaterials, CNTs-HAP and GR-HAP, through grafting of hydroxyapatite (HAP) to carbon nanotubes (CNTs) and graphene (GR) nanosheets. CNTs-HAP and GR-HAP have been tested for their cytotoxicity, growth and motility inhibitory effects, and their effects on the mesenchymal markers. All these demonstrated significant dose-dependent and time-dependent in vitro cytotoxicity against SUM-159 and MCF-7 breast cancer cell lines. The cell viability assay showed that the CNTs-HAP was more effective over SUM-159 cells than MCF-7 cells. It found that the increase in the concentration of GR-HAP has inhibited the clonogenic ability of breast cancer cells. The GR-HAP exhibited a substantial inhibitory effect on the cell motility of SUM-159 cell lines. It was investigated that the expression of vimentin (mesenchymal marker) was majorly reduced in SUM-159 cells by GR-HAP.

Biomaterial-assisted tumor therapy: A brief review of hydroxyapatite nanoparticles and its composites used in bone tumors therapy

Malignant bone tumors can inflict significant damage to affected bones, leaving patients to contend with issues like residual tumor cells, bone defects, and bacterial infections post-surgery. However, hydroxyapatite nanoparticles (nHAp), the principal inorganic constituent of natural bone, possess numerous advantages such as high biocompatibility, bone conduction ability, and a large surface area. Moreover, nHAp's nanoscale particle size enables it to impede the growth of various tumor cells via diverse pathways. This article presents a comprehensive review of relevant literature spanning the past 2 decades concerning nHAp and bone tumors. The primary goal is to explore the mechanisms responsible for nHAp's ability to hinder tumor initiation and progression, as well as to investigate the potential of integrating other drugs and components for bone tumor diagnosis and treatment. Lastly, the article discusses future prospects for the development of hydroxyapatite materials as a promising modality for tumor therapy.

Nanohydroxyapatite Stimulates PD-L1 Expression to Boost Melanoma Combination Immunotherapy

Although checkpoint-inhibitor immunotherapy held tremendous advances, improving immune response during treatment has always been an urgent clinical issue. With the help of mRNA microarray technology, it was found that short rod-like nanohydroxyapatite (nHA) promoted the upregulation of CD274 and PD-L1 related gene transcription, which was confirmed by the significantly enhanced PD-L1 expression level in B16, B16F10, and 4T1 cells in vitro. Hence, an injectable in situ responsive hydrogel reservoir embed with nHA and PD-1/PD-L1 inhibitor was engineered for a combination immunotherapy by peritumoral administration. The results confirmed that the combinational strategy effectively suppressed tumorigenesis and tumor growth, recovered the abnormal lactate dehydrogenase, aspartate transaminase, and alanine aminotransferase indicators, and significantly elongated the life span of a tumor-bearing mouse. The substantive progress mainly derived from nHA-induced T cell infiltration reinforcement in a tumor site and CD8⁺ T cell polarization in spleen, implying that nHA might function as an immunomodulator for melanoma immunotherapy.

Hydroxyapatite Biobased Materials for Treatment and Diagnosis of Cancer

Great advances in cancer treatment have been undertaken in the last years as a consequence of the development of new antitumoral drugs able to target cancer cells with decreasing side effects and a better understanding of the behavior of neoplastic cells during invasion and metastasis. Specifically, drug delivery systems (DDS) based on the use of hydroxyapatite nanoparticles (HAp NPs) are gaining attention and merit a comprehensive review focused on their potential applications. These are derived from the intrinsic properties of HAp (e.g., biocompatibility and biodegradability), together with the easy functionalization and easy control of porosity, crystallinity and morphology of HAp NPs. The capacity to tailor the properties of DLS based on HAp NPs has well-recognized advantages for the control of both drug loading and release. Furthermore, the functionalization of NPs allows a targeted uptake in tumoral cells while their rapid elimination by the reticuloendothelial system (RES) can be avoided. Advances in HAp NPs involve not only their use as drug nanocarriers but also their employment as nanosystems for magnetic hyperthermia therapy, gene delivery systems, adjuvants for cancer immunotherapy and nanoparticles for cell imaging.

Anti-melanoma effect and action mechanism of a novel chitosan-based composite hydrogel containing hydroxyapatite nanoparticles

Hydroxyapatite nanoparticles (HANPs) have been increasingly regarded and reported due to their potential anti-tumor ability. Previously, we found that the rod-like HANPs had good application potential for cutaneous melanoma (CMM). To satisfy the actual requirements in repairing post-operative skin defects and inhibiting CMM recurrence after tumorectomy, we constructed a novel chitosan/alginate (CS/Alg) hydrogel containing the aforementioned HANPs. The in vitro cell experiments confirmed that activated mitochondrial-dependent apoptosis was tightly related to the anti-tumor ability of HANPs. Specifically, we further discovered several target proteins might be involved in abnormal activating Wnt, proteoglycans in cancer, oxidative phosphorylation and p53 signaling pathways. The in vivo animal experiments demonstrated that the HANPs-loaded CS/Alg hydrogel (CS/Alg/HANPs) had a similar effect on inhibiting tumor growth as HANPs, and CS/Alg hydrogel as well as phosphate buffered saline (PBS) group (control) not showed any effect, proving the key role of HANPs. The immunohistochemical staining demonstrated a tumor inhibition via the mitochondria-mediated apoptosis pathway, consistent with the in vitro evaluation. Moreover, CS/Alg/HANPs exhibited no additional biosafety risk to the functions of major organs. Overall, this CS/Alg/HANPs hydrogel has substantial application potential for treating CMM.

Combination of Goniothalamin and Sol-Gel-Derived Bioactive Glass 45S5 Enhances Growth Inhibitory Activity via Apoptosis Induction and Cell Cycle Arrest in Breast Cancer Cells MCF-7

Background

Combination of natural products with chemically synthesised biomaterials as cancer therapy has attracted great interest lately. Hence, this study is aimed at investigating the combined effects of goniothalamin and bioactive glass 45S5 (GTN-BG) and evaluating their anticancer properties on human breast cancer cells MCF-7.

Methods

The BG 45S5 was prepared using the sol-gel process followed by characterisation using PSA, BET, SEM/EDS, XRD, and FTIR. The effects of GTN-BG on the proliferation of MCF-7 were assessed by MTT, PrestoBlue, and scratch wound assays. The cell cycle analysis, Annexin-FITC assay, and activation of caspase-3/7, caspase-8, and caspase-9 assays were determined to further explore its mechanism of action.

Results

The synthesised BG 45S5 was classified as a fine powder, having a rough surface, and contains mesopores of 12.6 nm. EDS analysis revealed that silica and calcium elements are the primary components of BG powders. Both crystalline and amorphous structures were detected with 73% and 27% similarity to Na2Ca2(Si2O7) and hydroxyapatite, respectively. The combination of GTN-BG was more potent than GTN in inhibiting the proliferation of MCF-7 cells. G0/G1 and G2/M phases of the cell cycle were arrested by GTN and GTN-BG. The percentage of viable cells in GTN-BG treatment was significantly lower than that in GTN. In terms of activation of initiator caspases for both extrinsic and intrinsic apoptosis pathways, caspase-8 and caspase-9 were found more effective in response to GTN-BG than GTN.

Conclusion

The anticancer effect of GTN in MCF-7 cells was improved when combined with BG. The findings provide significant insight into the mechanism of GTN-BG against MCF-7 cells, which can potentially be used as a novel anticancer therapeutic approach.

Using scaffolds as drug delivery systems to treat bone tumor

Surgery is the principal strategy to treat osteosarcoma and other types of bone tumors, but it causes bone defects that cannot be healed spontaneously. After surgery, patients still need to receive radiotherapy and/or chemotherapy to prevent tumor recurrence and metastasis, which leads to systemic side effects. Bone scaffolds exhibit the potentials to load cargos (drugs or growth factors) and act as drug delivery systems (DDSs) in the osteosarcoma postoperative treatment. This review introduces current types of bone scaffolds and highlights representative works using scaffolds as DDSs to treat osteosarcomas. Challenges and perspectives in the scaffold-based DDSs are also discussed. This review may provide references to develop effective and safe strategies for osteosarcoma postoperative treatment.

Loaded n-Hydroxyapatite/SSG 3D Scaffolds as a Drug Delivery System of Nigella sativa Fractions for the Management of Local Antibacterial Infections

As a result of their close similarities to the inorganic mineral components of human bone, hydroxyapatite nanoparticles (n-HAp) are widely used in biomedical applications and for the elaboration of biocompatible scaffold drug delivery systems for bone tissue engineering. In this context, a new efficient and economic procedure was used for the consolidation of n-HAp in the presence of various Nigella sativa (NS) fractions at a near-room temperature. The research conducted in the present study focuses on the physicochemical properties of loaded n-HAp 3D scaffolds by NS fractions and the in vitro antibacterial activity against Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 27853), and Gram-positive (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 700603) bacteria. In order to better understand the effect of the inserted fractions on the HAp molecular structure, the elaborated samples were subject to Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopic analyses. In addition, the morphological investigation by scanning electron microscope (SEM) of the loaded n-HAp 3D scaffolds demonstrated the presence of a porous structure, which is generally required in stimulating bone regeneration. Furthermore, the fabricated 3D composites exhibited significant antibacterial activity against all tested bacteria. Indeed, MIC values ranging from 5 mg/mL to 20 mg/mL were found for the HAp-Ethanol fraction (HAp-Et) and HAp-Hexane fraction (HAp-Hex), while the HAp-Aqueous fraction (HAp-Aq) and HAp-Methanol fraction (HAp-Me) showed values between 20 mg/mL and 30 mg/mL on the different strains. These results suggest that the HAp-NS scaffolds were effective as a drug delivery system and have very promising applications in bone tissue engineering.

Bone mineral: A trojan horse for bone cancers. Efficient mitochondria targeted delivery and tumor eradication with nano hydroxyapatite containing doxorubicin

Efficient systemic pharmacological treatment of solid tumors is hampered by inadequate tumor concentration of cytostatics necessitating development of smart local drug delivery systems. To overcome this, we demonstrate that doxorubicin (DOX), a cornerstone drug used for osteosarcoma treatment, shows reversible accretion to hydroxyapatite (HA) of both nano (nHA) and micro (mHA) size. nHA particles functionalized with DOX get engulfed in the lysosome of osteosarcoma cells where the acidic microenvironment causes a disruption of the binding between DOX and HA. The released DOX then accumulates in the mitochondria causing cell starvation, reduced migration and apoptosis. The HA+DOX delivery system was also tested in-vivo on osteosarcoma bearing mice. Locally delivered DOX via the HA particles had a stronger tumor eradication effect compared to the controls as seen by PET-CT and immunohistochemical staining of proliferation and apoptosis markers. These results indicate that in addition to systemic chemotherapy, an adjuvant nHA could be used as a carrier for intracellular delivery of DOX for prevention of tumor recurrence after surgical resection in an osteosarcoma. Furthermore, we demonstrate that nHA particles are pivotal in this approach but a combination of nHA with mHA could increase the safety associated with particulate nanomaterials while maintaining similar therapeutic potential.

Synergistic Combination of Bioactive Hydroxyapatite Nanoparticles and the Chemotherapeutic Doxorubicin to Overcome Tumor Multidrug Resistance

Multidrug resistance (MDR) is one of the biggest obstacles in cancer chemotherapy. Here, a remarkable reversal of MDR in breast cancer through the synergistic effects of bioactive hydroxyapatite nanoparticles (HAPNs) and doxorubicin (DOX) is shown. DOX loaded HAPNs (DHAPNs) exhibit a 150-fold reduction in IC₅₀ compared with free DOX for human MDR breast cancer MCF-7/ADR cells, and lead to almost complete inhibition of tumor growth in vivo without obvious side effects of free DOX. This high efficacy and specificity could be attributed to multiple action mechanisms of HAPNs. In addition to acting as the conventional nanocarriers to facilitate the cellular uptake and retention of DOX in MCF-7/ADR cells, more importantly, drug-free HAPNs themselves are able to prevent drug being pumped out of MDR cells through targeting mitochondria to induce mitochondrial damage and inhibit ATP production and to trigger sustained mitochondrial calcium overload and apoptosis in MDR cancer cells while not affecting normal cells. The results demonstrate that this simple but versatile bioactive nanoparticle provides a practical approach to effectively overcome MDR.

Fabrication of nanoparticles for bone regeneration: new insight into applications of nanoemulsion technology

Introducing synthetic bone substitutes into the clinic was a major breakthrough in the regenerative medicine of bone. Despite many advantages of currently available bone implant materials such as biocompatiblity and osteoconductivity, they still suffer from relatively poor bioactivity, osteoinductivity and osteointegration. These properties can be effectively enhanced by functionalization of implant materials with nanoparticles such as osteoinductive hydroxyapatite nanocrystals, resembling inorganic part of the bone, or bioactive polymer nanoparticles providing sustained delivery of pro-osteogenic agents directly at implantation site. One of the most widespread techniques for fabrication of nanoparticles for bone regeneration applications is nanoemulsification. It allows manufacturing of nanoscale particles (<100 nm) that are injectable, 3D-printable, offer high surface-area-to-volume-ratio and minimal mass transport limitations. Nanoparticles obtained by this technique are of particular interest for biomedical engineering due to fabrication procedures requiring low surfactant concentrations, which translates into reduced risk of surfactant-related in vivo adverse effects and improved biocompatibility of the product. This review discusses nanoemulsion technology and its current uses in manufacturing of nanoparticles for bone regeneration applications. In the first section, we introduce basic concepts of nanoemulsification including nanoemulsion formation, properties and preparation methods. In the next sections, we focus on applications of nanoemulsions in fabrication of nanoparticles used for delivery of drugs/biomolecules facilitating osteogenesis and functionalization of bone implants with special emphasis on biomimetic hydroxyapatite nanoparticles, synthetic polymer nanoparticles loaded with bioactive compounds and bone-targeting nanoparticles. We also highlight key challenges in formulation of nanoparticles via nanoemulsification and outline potential further improvements in this field.

Osteoconductive and electroactive carbon nanofibers/hydroxyapatite nanocomposite tailored for bone tissue engineering: in vitro and in vivo studies

In this study, we aimed to fabricate osteoconductive electrospun carbon nanofibers (CNFs) decorated with hydroxyapatite (HA) crystal to be used as the bone tissue engineering scaffold in the animal model. CNFs were derived from electrospun polyacrylonitrile (PAN) nanofibers via heat treatment and the carbonized nanofibers were mineralized by a biomimetic approach. The growth of HA crystals was confirmed using XRD, FTIR, and EDAX analysis techniques. The mineralization process turned the hydrophobic CNFs (WCA: 133.5° ± 0.6°) to hydrophilic CNFs/HA nanocomposite (WCA 15.3° ± 1°). The in vitro assessments revealed that the fabricated 24M-CNFs nanocomposite was biocompatible. The osteoconductive characteristics of CNFs/HA nanocomposite promoted in vivo bone formation in the rat’s femur defect site, significantly, observed by computed tomography (CT) scan images and histological evaluation. Moreover, the histomorphometric analysis showed the highest new bone formation (61.3 ± 4.2%) in the M-CNFs treated group, which was significantly higher than the negative control group (the defect without treatment) (< 0.05). To sum up, the results implied that the fabricated CNFs/HA nanocomposite could be considered as the promising bone healing material.

Hydroxyapatite as a biomaterial - a gift that keeps on giving

The synthetic analogue to biogenic apatite, hydroxyapatite (HA) has a number of physicochemical properties that make it an attractive candidate for diagnosis, treatment of disease and augmentation of biological tissues. Here we describe some of the recent studies on HA, which may provide bases for a number of new medical applications. The content of this review is divided to different medical application modes utilizing HA, including tissue engineering, medical implants, controlled drug delivery, gene therapies, cancer therapies and bioimaging. A number of advantages of HA over other biomaterials emerge from this discourse, including (i) biocompatibility, (ii) bioactivity, (iii) relatively simple synthesis protocols for the fabrication of nanoparticles with specific sizes and shapes, (iv) smart response to environmental stimuli, (v) facile functionalization and surface modification through noncovalent interactions, and (vi) the capacity for being simultaneously loaded with a wide range of therapeutic agents and switched to bioimaging modalities for uses in theranostics. A special section is dedicated to analysis of the safety of particulate HA as a component of parenterally administrable medications. It is concluded that despite the fact that many benefits come with the usage of HA, its deficiencies and potential side effects must be addressed before the translation to the clinical domain is pursued. Although HA has been known in the biomaterials world as the exemplar of safety, this safety proves to be the function of size, morphology, surface ligands and other structural and compositional parameters defining the particles. For this reason, each HA, especially when it comes in a novel structural form, must be treated anew from the safety research angle before being allowed to enter the clinical stage.

Anti-osteosarcoma effect of hydroxyapatite nanoparticles both in vitro and in vivo by downregulating the FAK/PI3K/Akt signaling pathway

Schematic representing the anti-cancer effects of nano-HAPs both in vitro and in vivo by downregulating the FAK/PI3K/Akt signaling pathway.

Synergistic antioxidant capacity of CsNPs and CurNPs against cytotoxicity, genotoxicity and pro-inflammatory mediators induced by hydroxyapatite nanoparticles in male rats

Due to their dynamic characteristics, hydroxyapatite nanoparticles (HAP-NPs) have been employed numerous times in nanomedicine and in tissue engineering, particularly as diagnostic and therapeutic agents. However, there are outstanding findings from various studies that question whether these NPs are safe when they are used in the human body. Therefore, a more in-depth toxicity assessment should be carried out to give a clear answer regarding the fate of these particles. Here we aim to investigate the possible cytotoxicity, genotoxicity and inflammation induced by HAP-NPs, as well as predict the synergistic antioxidative effect of chitosan nanoparticles (CsNPs) and curcumin nanoparticles (CurNPs) in mitigating this pronounced toxicity. The present study was conducted on eighty Wistar male rats, divided into eight equal groups. The results showed that, at the molecular level, HAP-NPs significantly induced gene expression of tumor suppressor protein p53, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and also Kidney Injury Molecule-1 (KIM-1) and Lipocalin-2 (LCN2). In addition, kidney biochemical parameters (total bilirubin, urea, uric acid and creatinine) increased, but albumin levels decreased in the group treated with HAP-NPs alone. Meanwhile, co-treatment with CsNPs and/or CurNPs with HAP-NPs showed an improvement in the activities of the kidney parameters and reduced inflammation. This study shows that the nephrotoxicity mechanism of HAP-NPs may involve various signaling pathways including alterations in biochemical parameters, gene expression of KIM-1 and LCN2 and disturbing the production of cytokines and p53. Furthermore, these insights showed that the combined effect of both CsNPs and CurNPs was more pronounced than the effect of each one on its own.

Application of hydroxyapatite nanoparticles in tumor-associated bone segmental defect

Hydroxyapatite (HA) has been widely applied in bone repair because of its superior biocompatibility. Recently, a proliferation-suppressive effect of HA nanoparticles (n-HA) against various cancer cells was reported. This study was aimed at assessing the translational value of n-HA both as a bone-regenerating material and as an antitumor agent. Inhibition of tumor growth, prevention of metastasis, and enhancement of the survival rate of tumor-bearing rabbits treated with n-HA were demonstrated. Activated mitochondrial-dependent apoptosis in vivo was confirmed, and we observed that a stimulated immune response was involved in the n-HA-induced antitumor effect. A porous titanium scaffold loaded with n-HA was fabricated and implanted into a critical-sized segmental bone defect in a rabbit tumor model. The n-HA-releasing scaffold not only showed a prominent effect in suppressing tumor growth and osteolytic lesion but also promoted bone regeneration. These findings provide a rationale for using n-HA in tumor-associated bone segmental defects.

3D Microfluidic Bone Tumor Microenvironment Comprised of Hydroxyapatite/Fibrin Composite

Bone is one of the most common sites of cancer metastasis, as its fertile microenvironment attracts tumor cells. The unique mechanical properties of bone extracellular matrix (ECM), mainly composed of hydroxyapatite (HA) affect a number of cellular responses in the tumor microenvironment (TME) such as proliferation, migration, viability, and morphology, as well as angiogenic activity, which is related to bone metastasis. In this study, we engineered a bone-mimetic microenvironment to investigate the interactions between the TME and HA using a microfluidic platform designed for culturing tumor cells in 3D bone-mimetic composite of HA and fibrin. We developed a bone metastasis TME model from colorectal cancer (SW620) and gastric cancer (MKN74) cells, which has very poor prognosis but rarely been investigated. The microfluidic platform enabled straightforward formation of 3D TME composed the hydrogel and multiple cell types. This facilitated monitoring of the effect of HA concentration and culture time on the TME. In 3D bone mimicking culture, we found that HA rich microenvironment affects cell viability, proliferation and cancer cell cytoplasmic volume in a manner dependent on the different metastatic cancer cell types and culture duration indicating the spatial heterogeneity (different origin of metastatic cancer) and temporal heterogeneity (growth time of cancer) of TME. We also found that both SW620 and MKN72 cells exhibited significantly reduced migration at higher HA concentration in our platform indicating inhibitory effect of HA in both cancer cells migration. Next, we quantitatively analyzed angiogenic sprouts induced by paracrine factors that secreted by TME and showed paracrine signals from tumor and stromal cell with a high HA concentration resulted in the formation of fewer sprouts. Finally we reconstituted vascularized TME allowing direct interaction between angiogenic sprouts and tumor-stroma microspheroids in a bone-mimicking microenvironment composing a tunable HA/fibrin composite. Our multifarious approach could be applied to drug screening and mechanistic studies of the metastasis, growth, and progression of bone tumors.

Nano hydroxyapatite induces glioma cell apoptosis by suppressing NF-κB signaling pathway

Nano-sized hydroxyapatite (nHA) particles have been demonstrated to exert anti-cancer effects on multiple cancer cell lines and animal models of cancer biology. However, the molecular mechanism underlying the effects of nHA particles on glioma cells remains unclear. The present study aimed to examine the effects of nHA on the behavior of glioma cells and investigate its underlying molecular mechanism. Rat glioma C6 cells and human glioma U87MG ATCC cells were exposed to nHA (20–100 µg/ml), and its effects on cell morphology, viability, apoptosis, cell cycle, invasion and nuclear factor (NF)-κB signaling were analyzed. Exposure of C6 and U87MG ATCC cells to 20 µg/ml nHA for 24 h caused cell detachment. Viability of C6 and U87MG ATCC cells were significantly reduced by nHA in a dose-dependent manner (P<0.05). Nuclear staining with Hoechst 33258 exhibited clear chromatin condensation in C6 cells following 24 h exposure to ≥25 µg/ml nHA. Flow cytometry revealed that nHA (20–100 µg/ml) significantly induced apoptosis and cell cycle G2/M arrest in C6 and U87MG ATCC cells (P<0.05). Transwell invasion assay demonstrated that nHA (20–60 µg/ml) significantly inhibited invasion of U87MG ATCC cells (P<0.05). Furthermore, western blotting and confocal immunofluorescence microscopy revealed that nHA (20–100 µg/ml) decreased NF-κB p65 protein expression and blocked NF-κB p65 nuclear translocation in C6 cells. The protein expression of NF-κB target molecules, such as B cell lymphoma 2, cyclooxygenase-2 and survivin, were also significantly reduced by nHA in a dose-dependent manner in both C6 and U87MG ATCC cells (P<0.05). In conclusion, it was demonstrated that the inhibitory effect of nHA on glioma cells is likely associated with the downregulation of NF-κB signaling.

The in vitro and in vivo anti-melanoma effects of hydroxyapatite nanoparticles: influences of material factors

Background

Treatment for melanoma is a challenging clinical problem, and some new strategies are worth exploring.

Purpose

The objective of this study was to investigate the in vitro and in vivo anti-melanoma effects of hydroxyapatite nanoparticles (HANPs) and discuss the involved material factors.

Materials and methods

Five types of HANPs, ie, HA-A, HA-B, HA-C, HA-D, and HA-E, were prepared by wet chemical method combining with polymer template and appropriate post-treatments. The in vitro effects of the as-prepared five HANPs on inhibiting the viability of A375 melanoma cells and inducing the apoptosis of the cells were evaluated by Cell Counting Kit-8 analysis, cell nucleus morphology observation, flow cytometer, and PCR analysis. The in vivo anti-melanoma effects of HANPs were studied in the tumor model of nude mice.

Results

The five HANPs had different physicochemical properties, including morphology, size, specific surface area (SSA), crystallinity, and so on. By the in vitro cell study, it was found that the material factors played important roles in the anti-melanoma effect of HANPs. Among the as-prepared five HANPs, HA-A with granular shape, smaller size, higher SSA, and lower crystallinity exhibited best effect on inhibiting the viability of A375 cells. At the concentration of 200 μg/mL, HA-A resulted in the lowest cell viability (34.90%) at day 3. All the HANPs could induce the apoptosis of A375 cells, and the relatively higher apoptosis rates of the cells were found in HA-A (20.10%) and HA-B (19.41%) at day 3. However, all the HANPs showed no inhibitory effect on the viability of the normal human epidermal fibroblasts. The preliminary in vivo evaluation showed that both HA-A and HA-C could delay the formation and growth speed of melanoma tissue significantly. Likely, HA-A exhibited better effect on inhibiting the growth of melanoma tissue than HA-C. The inhibition rate of HA-A for tumor tissue growth reached 49.1% at day 23.

Conclusion

The current study confirmed the anti-melanoma effect of HANPs and provided a new idea for the clinical treatment of melanoma.

3D Microfluidic Bone Tumor Microenvironment Comprised of Hydroxyapatite/Fibrin Composite

Bone is one of the most common sites of cancer metastasis, as its fertile microenvironment attracts tumor cells. The unique mechanical properties of bone extracellular matrix (ECM), mainly composed of hydroxyapatite (HA) affect a number of cellular responses in the tumor microenvironment (TME) such as proliferation, migration, viability, and morphology, as well as angiogenic activity, which is related to bone metastasis. In this study, we engineered a bone-mimetic microenvironment to investigate the interactions between the TME and HA using a microfluidic platform designed for culturing tumor cells in 3D bone-mimetic composite of HA and fibrin. We developed a bone metastasis TME model from colorectal cancer (SW620) and gastric cancer (MKN74) cells, which has very poor prognosis but rarely been investigated. The microfluidic platform enabled straightforward formation of 3D TME composed the hydrogel and multiple cell types. This facilitated monitoring of the effect of HA concentration and culture time on the TME. In 3D bone mimicking culture, we found that HA rich microenvironment affects cell viability, proliferation and cancer cell cytoplasmic volume in a manner dependent on the different metastatic cancer cell types and culture duration indicating the spatial heterogeneity (different origin of metastatic cancer) and temporal heterogeneity (growth time of cancer) of TME. We also found that both SW620 and MKN72 cells exhibited significantly reduced migration at higher HA concentration in our platform indicating inhibitory effect of HA in both cancer cells migration. Next, we quantitatively analyzed angiogenic sprouts induced by paracrine factors that secreted by TME and showed paracrine signals from tumor and stromal cell with a high HA concentration resulted in the formation of fewer sprouts. Finally we reconstituted vascularized TME allowing direct interaction between angiogenic sprouts and tumor-stroma microspheroids in a bone-mimicking microenvironment composing a tunable HA/fibrin composite. Our multifarious approach could be applied to drug screening and mechanistic studies of the metastasis, growth, and progression of bone tumors.

Folate-modified hydroxyapatite nanorods induce apoptosis in MCF-7 cells through a mitochondrial-dependent pathway

The targeted delivery of therapeutic drugs into cancer cells is a facile method to improve therapeutic efficacy.

Mitochondria: promising organelle targets for cancer diagnosis and treatment

Mitochondrial-mediated tumor monitoring provides a new perspective on mitochondria-based therapy.

Fabrication and Use of Poly(d,l-lactide-co-glycolide)-Based Formulations Designed for Modified Release of 5-Fluorouracil

5-fluorouracil (5-FU) is a chemotherapeutic agent that has been used for the treatment of a variety of malignancies since its initial introduction to the clinic in 1957. Owing to its short biological half-life, multiple dosings are generally required to maintain effective 5-FU plasma concentrations throughout the therapeutic period. Clinical studies have shown that continuous 5-FU administration is generally superior to bolus injection as exhibited by lower toxicities and increased therapeutic efficacy. Optimal therapeutic efficacy, however, is often compromised by the limiting therapeutic index. Whilst oral formulations are also used, these suffer from the drawbacks of variable bioavailability and first-pass metabolism. As a result, sustained release formulations of 5-FU have been investigated in an effort to mimic the kinetics of continuous infusion particularly for situations where local delivery is considered appropriate. The biocompatible, biodegradable, and highly tunable synthetic polymer, poly(d,l-lactide-co-glycolide) (PLGA), is widely used as a vector for sustained drug delivery, however, issues such as insufficient loading and inappropriate burst release kinetics have dogged progress into the clinic for small hydrophilic drugs such as 5-FU. This review provides introductory information about the mechanism of action, pharmacokinetic and physicochemical properties, and clinical use of 5-FU that have contributed to the development of PLGA-based 5-FU release platforms. In addition, this review provides information on fabrication methods used for a range of 5-FU-loaded PLGA formulations and discusses factors affecting the release kinetics of 5-FU as well as the in vitro and in vivo antitumor or antiproliferative efficacy of these platforms.

Iron oxide nanoparticles induced cytotoxicity, oxidative stress and DNA damage in lymphocytes

Over the past few decades nanotechnology and material science has progressed extremely rapidly. Iron oxide nanoparticles (IONPs) owing to their unique magnetic properties have a great potential for their biomedical and bioengineering applications. However, there is an inevitable need to address the issue of safety and health effects of these nanoparticles. Hence, the present study was aimed to assess the cytotoxic effects of IONPs on rats' lymphocytes. Using different assays, we studied diverse parameters including mitochondrial membrane potential, intracellular accumulation of reactive oxygen species (ROS), lactate dehydrogenase activity, antioxidant enzymes activity and DNA damage measurements. Intracellular metal uptake and ultrastructure analysis were also carried out through inductively coupled plasma atomic emission spectroscopy, transmission electron microscopy respectively. The results show that the IONP-induced oxidative stress was concentration-dependent in nature, with significant (P < 0.05) increase in ROS levels, lipid peroxidation level as well as depletion of antioxidant enzymes and glutathione. Moreover, we observed morphological changes in the cell after intracellular uptake and localization of nanoparticles in cells. From the findings of the study, it may be concluded that IONPs induce ROS-mediated cytotoxicity in lymphocytes. Copyright © 2017 John Wiley & Sons, Ltd.

Hydroxyapatite nanoparticle-induced mitochondrial energy metabolism impairment in liver cells: in vitro and in vivo studies

Hydroxyapatite nanoparticles (HAP-NPs) have been extensively developed as drug carriers, bone implants, coating materials, etc. in the human body. However, research focusing on the potential side effects of HAP-NPs on the mitochondria-associated energy metabolism in liver cells is lacking. In this study, HAP-NPs with a long diameter of 80 nm and a short diameter of 20 nm were evaluated for their ability to induce mitochondrial energy metabolism dysfunction in vitro and in vivo. In the in vitro system, the buffalo rat hepatocyte (BRL) cell line was directly exposed to the HAP-NPs. The results of these experiments showed that the HAP-NPs induced inhibition of mitochondrial dehydrogenase activity, which was accompanied by a decrease in the mitochondrial membrane potential (MMP). In addition, HAP-NPs elevated the hepatic levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and decreased the levels of GSH and SOD. These data indicated that HAP-NPs induced a lowered rate of electron transfer in the mitochondrial respiratory chain, accompanied by a decrease in the activity of the mitochondrial respiratory chain complexes I, II and III. Furthermore, HAP-NPs induced a decline in the enzymatic expression in the Krebs cycle. We also investigated the role of Kupffer cells (KCs, rat-derived) in the effects induced by the HAP-NPs. The supernatant from the HAP-NP-treated KCs was used to stimulate the BRL cells. We observed that the HAP-NPs had the ability to induce KC activation. The activation of KCs then led to the release of tumor necrosis factor-α (TNF-α), nitric oxide (NO) and reactive oxygen species (ROS), and induced the inhibition of mitochondrial respiratory chain complexes I, II and III in the BRL cells. In the in vivo study, the TEM examination revealed mitochondrial swelling and vacuolar degeneration in the HAP-NP-treated hepatocytes. In addition, the amount of succinate (Suc), an intermediate in the mitochondrial Krebs cycle, also declined in the ¹ H NMR spectroscopic measurements. Copyright © 2017 John Wiley & Sons, Ltd.

SUMO-1 Gene Silencing Inhibits Proliferation and Promotes Apoptosis of Human Gastric Cancer SGC-7901 Cells

Background: It has been reported that blocking small ubiquitin-like modifier (SUMO) conjugation by silencing SUMO gene remarkably decreased tumor growth in vivo. However, few studies have examined the relationship between SUMO gene silencing and gastric cancer (GC). The study aims to explore the effects of SUMO-1 gene silencing on GC cell proliferation and apoptosis. Methods: GC cells were cultured and divided into 5 groups: the blank group (without any transfection or treatment), the empty vector group (transfected with empty vector), the shRNA-SUMO-1-1 group (transfected with shRNA-SUMO-1-1 plasmid), the shRNA-SUMO-1-2 group (transfected with shRNA-SUMO-1-2 plasmid), and the shRNA-SUMO-1-3 group (transfected with shRNA-SUMO-1-3 plasmid). Cell Counting Kit-8 (CCK-8) assay was performed to examine cell proliferation. Annexin V/PI staining combined with flow cytometry were used to detect cell apoptosis. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were employed to measure the mRNA and protein expressions of SUMO-1, P53, Bcl-2 and c-myc, respectively. Results: SUMO-1 mRNA and protein expressions were decreased after transfecting with shRNA-SUMO-1. Compared with the blank group, the shRNA-SUMO-1-1 group presented a remarkable decreased proliferation of SGC-7901 cells. Significant increase in cell apoptosis rate was observed. Bcl-2, c-myc and P53 expressions were declined after transfecting with shRNA-SUMO plasmid. Conclusion: Our study provided evidence that SUMO-1 gene silencing could decrease proliferation and promote apoptosis in GC cells.

Facile Synthesis, Characterization, and Cytotoxic Activity of Europium-Doped Nanohydroxyapatite

The objective of this study was to synthetize europium-doped nanohydroxyapatite using a simple aqueous precipitation method and, thereafter, characterize and impregnate selected samples with 5-fluorouracil in order to explore the properties and the releasing capacity of this material. The nanohydroxyapatite was doped with 3, 5, 10, and 20 wt% of europium. The obtained samples were characterized after they were dried at 80°C and hydrothermal treated at 120°C by 2 hours. The samples were analyzed by transmission electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, and photoluminescence. Also, impregnation and release of 5-fluorouracil were assessed in PBS. The toxicity effects of all samples were studied using viability assays on human fibroblasts cells (HGF-1) in vitro. The sizes of the crystallites were about 10–70 nm with irregular morphology and present the phase corresponding to the JCPDS card 9–0432 for hydroxyapatite. The results of the toxicity experiments indicated that doped and undoped powders are biocompatible with fibroblasts cells. Hydroxyapatite samples doped with 5% of europium and loaded with 5-fluorouracil release almost 7 mg/L of the drug after 60 minutes in PBS and decrease the viability of HeLa cells after 24 hours.

Mitochondria-Targeted Hydroxyapatite Nanoparticles for Selective Growth Inhibition of Lung Cancer in Vitro and in Vivo

Lung cancer is the leading cause of cancer-related mortality worldwide. Most patients have metastases at the time of diagnosis, thus demanding development of more effective and specific agents. In this study, the specific anticancer effect of hydroxyapatite nanoparticles (HAPNs) to human lung cancer cells (A549) and the underlying mechanisms were investigated, using normal bronchial epithelial cells (16HBE) as the control. Rod-shaped HAPNs (∼10 nm in width and 50 nm in length) were prepared by aqueous precipitation method. Without any further functionalization and drug loading, HAPNs selectively inhibited cancer-cell proliferation. Their efficient mitochondrial targeting correlated strongly with decreased mitochondrial membrane potential and induction of mitochondria-dependent apoptosis in A549 cells. Caveolae-mediated endocytosis via lysosome trafficking was observed to be a prominent internalization pathway for HAPNs in both A549 and 16HBE cells. However, more nanoparticles were taken up into A549 cells. HAPNs triggered a sustained elevation of intracellular calcium concentration ([Ca²⁺]_i) in cancer cells but only a transitory increase in normal control cells. In a nude mouse lung cancer model with xenotransplanted A549 cells, HAPN treatment demonstrated nearly 40% tumor growth inhibition without apparent side effect. These results demonstrated that the enhanced cellular uptake and mitochondrial targeting of HAPNs, together with the prolonged elevation of [Ca²⁺]_i in A549 cells, could result in the cancer-specific cytotoxicity of HAPNs. Thus, HAPNs might be a promising agent or mitochondria-targeted delivery system for effective lung cancer therapy.

Engineered nanoparticles induce cell apoptosis: potential for cancer therapy

Engineered nanoparticles (ENPs) have been widely applied in industry, commodities, biology and medicine recently. The potential for many related threats to human health has been highlighted. ENPs with their sizes no larger than 100 nm are able to enter the human body and accumulate in organs such as brain, liver, lung, testes, etc, and cause toxic effects. Many references have studied ENP effects on the cells of different organs with related cell apoptosis noted. Understanding such pathways towards ENP induced apoptosis may aid in the design of effective cancer targeting ENP drugs. Such ENPs can either have a direct effect towards cancer cell apoptosis or can be used as drug delivery agents. Characteristics of ENPs, such as sizes, shape, forms, charges and surface modifications are all seen to play a role in determining their toxicity in target cells. Specific modifications of such characteristics can be applied to reduce ENP bioactivity and thus alleviate unwanted cytotoxicity, without affecting the intended function. This provides an opportunity to design ENPs with minimum toxicity to non-targeted cells.

Mitochondria and nuclei dual-targeted heterogeneous hydroxyapatite nanoparticles for enhancing therapeutic efficacy of doxorubicin

Dual-targeted nanoparticles have been increasingly used to realize greater anti-proliferation effect by attacking double key sites of tumor cells. In order to retain nuclei inhibition effect and enhance DOX-induced apoptosis by mitochondrial pathway simultaneously, hyaluronic acid (HA) modified hydroxyapatite (HAP) nanoparticles (HAP-HA), the functional calcium-based tumor targeting nanoparticles, have been developed. In this nanosystem, HA acts as an active tumor-targeting ligand to bind the CD44 receptors which are overexpressed on the surface of tumor cells while HAP can load and deliver DOX to both nuclei and mitochondria of tumor cells. In this study, DOX-loaded HAP-HA nanoparticles (DOX/HAP-HA) exhibited satisfactory drug loading efficiency which was up to 214.55 ± 51.05 μg mg(-1) and showed a uniform nano-scaled particle size. The mitochondrial and nuclei targetability of DOX/HAP-HA was confirmed by confocal laser scanning microscopy analyses. Besides, western blot assay demonstrated that DOX/HAP-HA could markedly enhance mitochondrial cytochrome C leakage and thereby activate apoptotic cascade associated with it. In addition, in vivo anti-tumor efficacy and toxicity evaluation of DOX/HAP-HA indicated that DOX/HAP-HA was more effective and less harmful compared to other groups. DOX/HAP-HA might be a new promising targeted delivery system for effective cancer therapy.

Development of lattice-inserted 5-Fluorouracil-hydroxyapatite nanoparticles as a chemotherapeutic delivery system

Developing an effective vehicle for cancer treatment, hydroxyapatite nanoparticles were fabricated for drug delivery. When 5-Fluorouracil, a major chemoagent, is combined with hydroxyapatite nanocarriers by interclay insertion, the modified hydroxyapatite nanoparticles have superior lysosomal degradation profiles, which could be leveraged as controlled drug release. The decomposition of the hydroxyapatite nanocarriers facilitates the release of 5-Fluorouracil into the cytoplasm causing cell death. Hydroxyapatite nanoparticles with/without 5-Fluorouracil were synthesized and analyzed in this study. Their crystallization properties and chemical composition were examined by X-ray diffraction and Fourier transforms infrared spectroscopy. The 5-Fluorouracil release rate was determined by UV spectroscopy. The biocompatibility of hydroxyapatite-5-Fluorouracil extraction solution was assessed using 3T3 cells via a WST-8 assay. The effect of hydroxyapatite-5-Fluorouracil particles which directly work on the human lung adenocarcinoma (A549) cells was evaluated by a lactate dehydrogenase assay via contact cultivation. A 5-Fluorouracil-absorbed hydroxyapatite particles were also tested. Overall, hydroxyapatite-5-Fluorouracils were prepared using a co-precipitation method wherein 5-Fluorouracil was intercalated in the hydroxyapatite lattice as determined by X-ray diffraction. Energy dispersive scanning examination showed the 5-Fluorouracil content was higher in hydroxyapatite-5-Fluorouracil than in a prepared absorption formulation. With 5-Fluorouracil insertion in the lattice, the widths of the a and c axial constants of the hydroxyapatite crystal increased. The extraction solution of hydroxyapatite-5-Fluorouracil was nontoxic to 3T3 cells, in which 5-Fluorouracil was not released in a neutral phosphate buffer solution. In contrast, at a lower pH value (2.5), 5-Fluorouracil was released by the acidic decomposition of hydroxyapatite. Finally, the results of the lactate dehydrogenase assay revealed that 5-Fluorouracil-hydroxyapatite was highly toxic to A549 cells through direct culture, this phenomenon may result from lysosomal decomposition of particles causing 5-Fluorouracil releasing. The pH-responsive hydroxyapatite-5-Fluorouracil nanoparticles have the potential to be part of a selective drug-delivery system in chemotherapy for cancer treatment.

Anticancer effect of 2,7-dihydroxy-3-methylanthraquinone on human gastric cancer SGC-7901 cells in vitro and in vivo

CONTEXT

2,7-Dihydroxy-3-methylanthraquinone (DDMN) is reported to have a remarkable anticancer activity against gastric cancer SGC-7901 cells.

OBJECTIVE

The objective of this study is to study the anticancer effect and mechanism of DDMN on SGC-7901 cells.

MATERIALS AND METHODS

The MTT assay was used to determine the effect of DDMN on cell viability of SGC-7901 cells, and the cytotoxic effect was evaluated by the IC50 value. After treatment with different doses of DDMN (10, 20, and 40 μM) for 48 h, flow cytometry was used to investigate the apoptosis of SGC-7901 cells induced by DDMN. Further, western blotting was performed to study anticancer mechanism by assaying apoptosis-related proteins containing Mcl-1, Bcl-xl, Bcl-2, Bax, Bak, Bad, cytochrome c, caspase-3, and caspase-9. Finally, xenograft assay was used to further evaluate the effect of DDMN on SGC-7901 cells by determining body weight of nude mice, tumor volumes, and apoptosis-related proteins.

RESULTS

These results suggest that DDMN can significantly inhibit (IC50 value = 20.92 μM) the proliferation of SGC-7901 cells and induce apoptosis of SGC-7901 cells demonstrated by flow cytometry analysis. Additionally, the results of western blotting indicated that DDMN can suppress the expression of anti-apoptotic proteins Bcl-xl and Bcl-2, increase the expression of pro-apoptotic proteins Bax, Bad (40 μM), caspase-3 and caspase-9, and evidently promote the release of cytochrome c from the mitochondria to the cytoplasm. The xenograft assay further confirmed that DDMN had significant anticancer effects on SGC-7901 cells.

CONCLUSION

DDMN had significant anticancer effect on SGC-7901 cells in vitro and in vivo related to mitochondria-mediated apoptosis.

Extract of Zuojin Pill ([characters: see text]) induces apoptosis of SGC-7901 cells via mitochondria-dependent pathway

OBJECTIVE

To observe the effects of water extract of Zuojin Pill ([characters: see text], ZJP) on inhibiting the growth of human gastric cancer cell line SGC-7901 and its potential mechanism.

METHODS

Effects of ZJP on SGC-7901 cells growth were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, cell apoptosis and cell cycle were determined by flow cytometry, and apoptosis induction was detected by means of DNA gel electrophoresis. The cellular mechanism of drug-induced cell death was unraveled by assaying oxidative injury level of SGC-7901 cell, mitochondrial membrane potentials, expression of apoptosis-related genes, such as B cell lymphoma/lewkmia-2 (Bcl-2), Bcl-2 associated X protein (Bax) and cleaved caspase-3 and caspase-9.

RESULTS

ZJP exerted evident inhibitory effect on SGC-7901 cells by activating production of reactive oxygen species and elevating Bax/Bcl-2 ratio in SGC-7901 cells, leading to attenuation of mitochondrial membrane potential and DNA fragmentation.

CONCLUSIONS

ZJP inhibits the cancer cell growth via activating mitochondria-dependent apoptosis pathway. ZJP can potentially serve as an antitumor agent.

Integrative nanomedicine: treating cancer with nanoscale natural products

Finding safer and more effective treatments for specific cancers remains a significant challenge for integrative clinicians and researchers worldwide. One emerging strategy is the use of nanostructured forms of drugs, vaccines, traditional animal venoms, herbs, and nutraceutical agents in cancer treatment. The recent discovery of nanoparticles in traditional homeopathic medicines adds another point of convergence between modern nanomedicine and alternative interventional strategies. A way in which homeopathic remedies could initiate anticancer effects includes cell-to-cell signaling actions of both exogenous and endogenous (exosome) nanoparticles. The result can be a cascade of modulatory biological events with antiproliferative and pro-apoptotic effects. The Banerji Protocols reflect a multigenerational clinical system developed by homeopathic physicians in India who have treated thousands of patients with cancer. A number of homeopathic remedy sources from the Banerji Protocols (eg, Calcarea phosphorica; Carcinosin-tumor-derived breast cancer tissue prepared homeopathically) overlap those already under study in nonhomeopathic nanoparticle and nanovesicle tumor exosome cancer vaccine research. Past research on antineoplastic effects of nano forms of botanical extracts such as Phytolacca, Gelsemium, Hydrastis, Thuja, and Ruta as well as on homeopathic remedy potencies made from the same types of source materials suggests other important overlaps. The replicated finding of silica, silicon, and nano-silica release from agitation of liquids in glassware adds a proven nonspecific activator and amplifier of immunological effects. Taken together, the nanoparticulate research data and the Banerji Protocols for homeopathic remedies in cancer suggest a way forward for generating advances in cancer treatment with natural product-derived nanomedicines.

The inhibition of lamellar hydroxyapatite and lamellar magnetic hydroxyapatite on the migration and adhesion of breast cancer cells

Hydroxyapatite nanoparticles have been reported to exhibit potent anti-tumor effects in some cancer cells. In our previous study, we have successfully synthesized two types of hydroxyapatite nanoparticles, laminated hydroxyapatite (L-HAp) and laminated magnetic hydroxyapatite (LM-HAp). In this study, we wanted to investigate the effects of L-HAp and LM-HAp with various concentrations on human breast cancer MDA-MB-231 cells. Cell proliferation was assessed with a MTT colorimetric assay. Scratch and adhesion assays were used to detect the effects of these two materials on migration and adhesion. The expressions of integrin β1 and Akt were measured by Western blotting. Our results showed that L-HAp and LM-HAp had little cell cytotoxicity and significantly reduced cell mobility and adhesion. LM-HAp showed greater inhibitor ability on migration and adhesion of MDA-MB-231 cells. Moreover, results from western blotting showed that L-HAp and LM-HAp impacted the phosphorylation of integrin β1, but showed no regular impact on Akt. This study suggests that L-HAp and LM-HAp may be potential anti-tumor and delivery system for breast cancer therapy.

Differential cytotoxicity and particle action of hydroxyapatite nanoparticles in human cancer cells

Aim: While hydroxyapatite nanoparticles (HAPNs) have been reported to exhibit anticancer effects on several types of human cancer cells, no investigation has been performed to compare their cytotoxicity with different types of cancer cells. The objective of the present study is to investigate the cytotoxic action of HAPNs in different types of human cancer cell and to explore the possible mechanisms involved. Materials & methods: Rod-shaped HAPNs were prepared by the aqueous precipitation method and then labeled with ?uorescein isothiocyanate to visualize the cellular uptake and distribution. Their cytotoxicity to three human carcinoma cell lines (gastric cancer cells [MGC80-3], cervical adenocarcinoma epithelial cells [HeLa] and hepatoma cells [HepG2], as well as to normal human hepatocyte cells [L-02]) was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was characterized by the changes in nuclear morphology with 4’,6-diamidino-2-phenylindole staining and by ?ow cytometric analysis with Annexin V-?uorescein isothiocyanate/propidium iodide double staining. Furthermore, the activity of apoptotic proteins (caspase-3, -8 and -9), intracellular reactive oxygen species and glutathione levels were analyzed in HAPN-treated cells. The cellular uptake of HAPNs was studied using flow cytometry analysis, and changes in intracellular calcium levels were investigated using the Ca2+-sensitive fluorescent dye, fluo-3 AM. Results: HAPNs significantly inhibited cell proliferation and induced apoptosis of cancer cells with an order of MGC80-3 > HepG2 > HeLa, but had no impact on normal hepatic cells (L-02). The increase in apoptosis was accompanied by the activation of caspase-3 and -9, but not activation of caspase-8. Moreover, HAPN treatment led to reactive oxygen species generation and decreased intracellular glutathione in cancer cells, with the most remarkable reactive oxygen species burst in HeLa cells. The degree of cytotoxicity did not correlate with the cellular uptake efficiency of HAPNs. However, more HAPNs were found inside the nucleus of MGC80-3 cells, and an increase in the intracellular calcium level was observed in all cancer cells, with the highest level also detected in MGC80-3. Conclusion: Varying cytotoxicity of HAPNs was observed in different cancer cell types. Our results suggest that possible mechanisms of cytotoxicity in various types of cancer cells could be different. The elevated calcium concentration and nuclear localization of the particles might be the main mechanism of growth inhibition by HAPNs in cancer cells.

Original submitted 18 April 2012; Revised submitted 14 September 2012; Published online 24 April 2013

Suitability of cell-based label-free detection for cytotoxicity screening of carbon nanotubes

Cytotoxicity testing of nanoparticles (NPs) by conventional screening assays is often complicated by interference. Carbon nanotubes (CNTs) are particularly difficult to assess. To test the suitability of cell-based label-free techniques for this application, a panel of CNTs with different diameters and surface functionalizations was assessed by impedance-based technique (xCELLigence RTCA) and automated microscopy (Cell-IQ) compared to formazan bioreduction (MTS assay). For validation of the label-free systems different concentrations of ethanol and of amine (AMI) polystyrene NPs were used. CNTs were evaluated in various cell lines, but only endothelial EAhy926 cells and L929 and V79 fibroblasts could be evaluated in all systems. Polystyrene particles obtained similar results in all assays. All systems identified thin (<8 nm) CNTs as more cytotoxic than thick (>20 nm) CNTs, but detection by xCELLigence system was less sensitive to CNT-induced cytotoxicity. Despite advantages, such as continuous monitoring and more detailed analysis of cytotoxic effects, label-free techniques cannot be generally recommended for cytotoxicity screening of NPs.

Amorphous calcium phosphate nanoparticles could function as a novel cancer therapeutic agent by employing a suitable targeted drug delivery platform

Employment of nanovehicular system for delivering apoptogenic agent to cancer cells for inducing apoptosis has widely been investigated. Loading efficacy and controlled release of the agents are of the inseparable obstacles that hamper the efforts in reaching an efficacious targeted cancer therapy method. When the carrier itself is apoptogenic, then there is no need to load the carrier with apoptogenic agent and just delivering of the particle to the specific location matters. Hence, we hypothesize that amorphous calcium phosphate nanoparticle (ACPN) is a potent candidate for apoptosis induction, although encapsulation in liposome shell, and surface decoration with targeting ligand (TL), and cell-penetrating peptide (CPP) plays a pivotal role in the employment of this agent. It is well understood that elevation in cytosolic Ca2+ ([Ca2+]c) would result in the induction of apoptosis. ACPN has the potential to cause imbalance in this medium by elevating [Ca2+]c. Owning to the fact that the nanoparticles should be delivered into cytosol, it is necessary to trap them in a liposomal shell for evading endocytosis. It was demonstrated that employment of the trans-activator of transcription (TAT) as CPP eminently enhances the efficacy of endosomal escape; therefore, the platform is designed in a way that TAT is positioned on the surface of the liposome. Due to the fact that the apoptosis should be induced in sole cancer cells, Folate as TL is also attached on the surface of the liposome. This hypothesis heralds the new generation of chemotherapeutic agents and platforms which could have less side effect than the most common ones, in addition to other advantages they have.

Antiproliferative effect of silver nanoparticles synthesized using amla on Hep2 cell line

OBJECTIVE

To synthesize silver nanoparticles by amla extract, screen the cytotoxic, oxidative stress and apoptotic effect of silver nanoparticles (AgNPs) on Hep2 cell line (laryngeal carcinoma cells) in vitro, and to compare the effect of Phyllanthus emblica (P. emblica) (amla) with AgNPs synthesized by amla and 5-FU.

METHODS

AgNPs was synthesized by P. emblica (aqueous extract) and nanoparticles were characterized UV-Vis spec, the presence of biomoloecules of amla capped in AgNPs was found by FT-IR analysis, shape and size were examined by SEM and DLS. Cytotoxicity of experimental drugs was tested to find IC(50) value. ROS generation in cells have been measured by DCFH-DA staining, AO-EtBr, Rhodamine-123 staining and DNA fragmentation were performed to assess apoptotic cell death, mitochondrial membrane potential and apoptotic DNA damage, respectively. Oxidative stress was analyzed by measuring lipid peroxides and antioxidants level to understand the cancer cell death by pro-oxidant mechanism.

RESULTS

PE-AgNPs was synthesized and confirmed through kinetic behavior of NPs. The shape of PE-AgNPs was spherical and cubic since it was agglomerated, and the nanoparticle surface was complicated. Average particle size distribution of PE-AgNPs was found to be 188 nm. Potent biomolecules of P. emblica such as polyphenols were capped with AgNPs and reduced its toxicity. In cytotoxicity assay the concentration in which the maximum number of cell death was 60 μg/mL and 50 μg/mL for P. emblica (alone) and AgNPs, respectively and IC(50) values were fixed as 30 μg/mL and 20 μg/mL. ROS generation, apoptotic morphological changes, mitochondrial depolarization, DNA damage and oxidative stress was observed as more in AgNPs treated cells than in P. emblica (30 μg/mL) (alone) treated cells and 5-FU treated cells gave similar result.

CONCLUSIONS

The results suggest that the AgNPs are capped with biomolecules of amla enhanced cytotoxicity in laryngeal cancer cells through oxidative stress and apoptotic function on Hep2 cancer cells.

Fetuin-A-containing calciprotein particles reduce mineral stress in the macrophage

The formation of fetuin-A-containing calciprotein particles (CPP) may facilitate the clearance of calcium phosphate nanocrystals from the extracellular fluid. These crystals may otherwise seed extra-osseous mineralization. Fetuin-A is a partially phosphorylated glycoprotein that plays a critical role in stabilizing these particles, inhibiting crystal growth and aggregation. CPP removal is thought to be predominantly mediated by cells of the reticuloendothelial system via type I and type II class A scavenger receptor (SR-AI/II). Naked calcium phosphate crystals are known to stimulate macrophages and other cell types in vitro, but little is known of the effect of CPP on these cells. We report here, for the first time, that CPP induce expression and secretion of tumour necrosis factor (TNF)-α, interleukin (IL)-1β in murine RAW 264.7 macrophages. Importantly, however, CPP induced significantly lower cytokine secretion than hydroxyapatite (HAP) crystals of equivalent size and calcium content. Furthermore, CPP only had a modest effect on macrophage viability and apoptosis, even at very high levels, compared to HAP crystals, which were strongly pro-apoptotic at much lower levels. Fetuin-A phosphorylation was found to modulate the effect of CPP on cytokine secretion and apoptosis, but not uptake via SR-AI/II. Prolonged exposure of macrophages to CPP was found to result in up-regulated expression of SR-AI/II. CPP formation may help protect against some of the pro-inflammatory and harmful effects of calcium phosphate nanocrystals, perhaps representing a natural defense system for calcium mineral stress. However, in pathological states where production exceeds clearance capacity, these particles may still stimulate pro-inflammatory and pro-apoptotic cascades in macrophages, which may be important in the pathogenesis of vascular calcification.

An investigation on the cytotoxicity and caspase-mediated apoptotic effect of biologically synthesized silver nanoparticles using Podophyllum hexandrum on human cervical carcinoma cells

Now-a-days synthesis and characterization of silver nanoparticles (AgNPs) through biological entity is quite interesting to employ AgNPs for various biomedical applications in general and treatment of cancer in particular. This paper presents the green synthesis of AgNPs using leaf extract of Podophyllum hexandrum Royle and optimized with various parameters such as pH, temperature, reaction time, volume of extract and metal ion concentration for synthesis of AgNPs. TEM, XRD and FTIR were adopted for characterization. The synthesized nanoparticles were found to be spherical shaped with average size of 14 nm. Effects of AgNPs were analyzed against human cervical carcinoma cells by MTT Assay, quantification of ROS, RT-PCR and western blotting techniques. The overall result indicates that AgNPs can selectively inhibit the cellular mechanism of HeLa by DNA damage and caspase mediated cell death. This biological procedure for synthesis of AgNPs and selective inhibition of cancerous cells gives an alternative avenue to treat human cancer effectively.

Systematic review: the applications of nanotechnology in gastroenterology

BACKGROUND

Over the past 30 years, nanotechnology has evolved dramatically. It has captured the interest of variety of fields from computing and electronics to biology and medicine. Recent discoveries have made invaluable changes to future prospects in nanomedicine; and introduced the concept of theranostics. This term offers a patient specific 'two in one' modality that comprises of diagnostic and therapeutic tools. Not only nanotechnology has shown great impact on improvements in drug delivery and imaging techniques, but also there have been several ground-breaking discoveries in regenerative medicine.

AIM

Gastroenterology invites multidisciplinary approach owing to high complexity of gastrointestinal (GI) system; it includes physicians, surgeons, radiologists, pharmacologists and many more. In this article, we concentrate on current developments in nano-gastroenterology.

METHODS

Literature search was performed using Web of Science and Pubmed search engines with terms--nanotechnology, nanomedicine and gastroenterology. Article search was concentrated on developments since 2005.

RESULTS

We have described original and innovative approaches in gastrointestinal drug delivery, inflammatory disease and cancer-target treatments. Here, we have reviewed advances in GI imaging using nanoparticles as fluorescent contrast, and their potential for site-specific targeting. This review has also depicted various approaches and novel discoveries in GI regenerative medicine using nanomaterials for scaffold designs and induced pluripotent stem cells as cell source.

CONCLUSIONS

Developments in nanotechnology have opened new range of possibilities to help our patients. This includes novel drug delivery vehicles, diagnostic tools for early and targeted disease detection and nanocomposite materials for tissue constructs to overcome cosmetic or physical disabilities.

Proteomic identification of a novel hsp90-containing protein-mineral complex which can be induced in cells in response to massive calcium influx

Fetuin-A is known for limiting the expansion and formation of hydroxyapatite crystals from calcium phosphate aggregates in circulation by forming a soluble fetuin-mineral complex. This study was aimed to uncover potential proteins involved in the regulation of calcium phosphate precipitation within cells. We found that a novel protein-mineral complex (PMC) can be generated after introduction of calcium chloride and sodium phosphate into the porcine brain protein extract prepared in Tris-HCl buffer. Selectively enriched proteins in the pellet were confirmed by immunoblotting, including heat shock protein 90 (Hsp90), annexin A5, calreticulin, nucleolin, and other proteins. In addition, purified native Hsp90 directly bound both amorphous calcium phosphate and hydroxyapatite and underwent conformational changes and oligomerization in the presence of excess calcium and phosphate. The morphology of the PMC prepared from Hsp90, calcium, and phosphate was distinctly different from that of hydroxyapatite under transmission electron microscope observation. When cultured SiHa cells were treated with a calcium ionophore or damaged by scratch to induce the massive calcium influx, a complex was formed and observed at discrete sites near the plasma membrane as revealed by antibodies against Hsp90, annexin A5, calreticulin, nucleolin, and other proteins. This complex could also be probed in situ with fetuin-A suggesting the existence of calcium phosphate aggregates in this complex. Inhibition of the complex formation by bisphosphonates hindered cell recovery from A23187 assault. Our results show that following membrane damage amorphous calcium phosphate develops at sites near membrane rupture where saturated calcium phosphate concentration is achieved. As a result, Hsp90 and other proteins are recruited, and the cytosolic PMC is formed. Inhibition of the cytosolic PMC formation may in part contribute to the cellular toxicity and in vivo side effects of bisphosphonates, particularly in cells prone to membrane damage under physiological conditions such as gastrointestinal epithelial and oral cavity epithelial cells.