Nanomaterials in crossroad of autophagy control in human cancers: Amplification of cell death mechanisms

Cancer is the result of genetic abnormalities that cause normal cells to grow into neoplastic cells. Cancer is characterized by several distinct features, such as uncontrolled cell growth, extensive spreading to other parts of the body, and the ability to resist treatment. The scientists have stressed the development of nanostructures as novel therapeutic options in suppressing cancer, in response to the emergence of resistance to standard medicines. One of the specific mechanisms with dysregulation during cancer is autophagy. Nanomaterials have the ability to specifically carry medications and genes, and they can also enhance the responsiveness of tumor cells to standard therapy while promoting drug sensitivity. The primary mechanism in this process relies on autophagosomes and their fusion with lysosomes to break down the components of the cytoplasm. While autophagy was initially described as a form of cellular demise, it has been demonstrated to play a crucial role in controlling metastasis, proliferation, and treatment resistance in human malignancies. The pharmacokinetic profile of autophagy modulators is poor, despite their development for use in cancer therapy. Consequently, nanoparticles have been developed for the purpose of delivering medications and autophagy modulators selectively and specifically to the cancer process. Furthermore, several categories of nanoparticles have demonstrated the ability to regulate autophagy, which plays a crucial role in defining the biological characteristics and response to therapy of tumor cells.

Important Factors Affecting Induction of Cell Death, Oxidative Stress and DNA Damage by Nano- and Microplastic Particles In Vitro

We have described the influence of selected factors that increase the toxicity of nanoplastics (NPs) and microplastics (MPs) with regard to cell viability, various types of cell death, reactive oxygen species (ROS) induction, and genotoxicity. These factors include plastic particle size (NPs/MPs), zeta potential, exposure time, concentration, functionalization, and the influence of environmental factors and cell type. Studies have unequivocally shown that smaller plastic particles are more cytotoxic, penetrate cells more easily, increase ROS formation, and induce oxidative damage to proteins, lipids, and DNA. The toxic effects also increase with concentration and incubation time. NPs with positive zeta potential are also more toxic than those with a negative zeta potential because the cells are negatively charged, inducing stronger interactions. The deleterious effects of NPs and MPs are increased by functionalization with anionic or carboxyl groups, due to greater interaction with cell membrane components. Cationic NPs/MPs are particularly toxic due to their greater cellular uptake and/or their effects on cells and lysosomal membranes. The effects of polystyrene (PS) vary from one cell type to another, and normal cells are more sensitive to NPs than cancerous ones. The toxicity of NPs/MPs can be enhanced by environmental factors, including UV radiation, as they cause the particles to shrink and change their shape, which is a particularly important consideration when working with environmentally-changed NPs/MPs. In summary, the cytotoxicity, oxidative properties, and genotoxicity of plastic particles depends on their concentration, duration of action, and cell type. Also, NPs/MPs with a smaller diameter and positive zeta potential, and those exposed to UV and functionalized with amino groups, demonstrate higher toxicity than larger, non-functionalized and environmentally-unchanged particles with a negative zeta potential.

Autophagy regulation by inorganic, organic, and organic/inorganic hybrid nanoparticles: Organelle damage, regulation factors, and potential pathways

The rapid development of nanotechnology requires a more thorough understanding of the potential health effects caused by nanoparticles (NPs). As a programmed cell death, autophagy is one of the biological effects induced by NPs, which maintain intracellular homeostasis by degrading damaged organelles and removing aggregates of defective proteins through lysosomes. Currently, autophagy has been shown to be associated with the development of several diseases. A significant number of research have demonstrated that most NPs can regulate autophagy, and their regulation of autophagy is divided into induction and blockade. Studying the autophagy regulation by NPs will facilitate a more comprehensive understanding of the toxicity of NPs. In this review, we will illustrate the effects of different types of NPs on autophagy, including inorganic NPs, organic NPs, and organic/inorganic hybrid NPs. The potential mechanisms by which NPs regulate autophagy are highlighted, including organelle damage, oxidative stress, inducible factors, and multiple signaling pathways. In addition, we list the factors influencing NPs-regulated autophagy. This review may provide basic information for the safety assessment of NPs.

New trends in diagnosing and treating ovarian cancer using nanotechnology

Ovarian cancer stands as the fifth most prevalent cancer among women, causing more mortalities than any other disease of the female reproductive system. There are numerous histological subtypes of ovarian cancer, each of which has distinct clinical characteristics, risk factors, cell origins, molecular compositions, and therapeutic options. Typically, it is identified at a late stage, and there is no efficient screening method. Standard therapies for newly diagnosed cancer are cytoreductive surgery and platinum-based chemotherapy. The difficulties of traditional therapeutic procedures encourage researchers to search for other approaches, such as nanotechnology. Due to the unique characteristics of matter at the nanoscale, nanomedicine has emerged as a potent tool for creating novel drug carriers that are more effective and have fewer adverse effects than traditional treatments. Nanocarriers including liposomes, dendrimers, polymer nanoparticles, and polymer micelles have unique properties in surface chemistry, morphology, and mechanism of action that can distinguish between malignant and normal cells, paving the way for targeted drug delivery. In contrast to their non-functionalized counterparts, the development of functionalized nano-formulations with specific ligands permits selective targeting of ovarian cancers and ultimately increases the therapeutic potential. This review focuses on the application of various nanomaterials to the treatment and diagnosis of ovarian cancer, their advantages over conventional treatment methods, and the effective role of controlled drug delivery systems in the therapy of ovarian cancer.

Promising Nanomedicines of Shikonin for Cancer Therapy

Malignant tumor, the leading cause of death worldwide, poses a serious threat to human health. For decades, natural product has been proven to be an essential source for novel anticancer drug discovery. Shikonin (SHK), a natural molecule separated from the root of Lithospermum erythrorhizon, shows great potential in anticancer therapy. However, its further clinical application is significantly restricted by poor bioavailability, adverse effects, and non-selective toxicity. With the development of nanotechnology, nano drug delivery systems have emerged as promising strategies to improve bioavailability and enhance the therapeutic efficacy of drugs. To overcome the shortcoming of SHK, various nano drug delivery systems such as liposomes, polymeric micelles, nanoparticles, nanogels, and nanoemulsions, were developed to achieve efficient delivery for enhanced antitumor effects. Herein, this review summarizes the anticancer pharmacological activities and pharmacokinetics of SHK. Additionally, the latest progress of SHK nanomedicines in cancer therapy is outlined, focusing on long circulation, tumor targeting ability, tumor microenvironment responsive drug release, and nanosystem-mediated combination therapy. Finally, the challenges and prospects of SHK nanomedicines in the future clinical application are spotlighted.

Mitophagy Induced by Metal Nanoparticles for Cancer Treatment

Research on nanoparticles, especially metal nanoparticles, in cancer therapy is gaining momentum. The versatility and biocompatibility of metal nanoparticles make them ideal for various applications in cancer therapy. They can bring about apoptotic cell death in cancer cells. In addition to apoptosis, nanoparticles mediate a special type of autophagy facilitated through mitochondria called mitophagy. Interestingly, nanoparticles with antioxidant properties are capable of inducing mitophagy by altering the levels of reactive oxygen species and by influencing signaling pathways like PINK/Parkin pathway and P13K/Akt/mTOR pathway. The current review presents various roles of metal nanoparticles in inducing mitophagy in cancer cells. We envision this review sheds some light on the blind spots in the research related to mitophagy induced by nanoparticles for cancer treatment.

Polymeric nanoparticles-siRNA as an emerging nano-polyplexes against ovarian cancer

Ovarian cancer (OC) is considered fifth-deadliest cancer globally responsible for high mortality in women. As the conventional therapeutic and diagnostic approaches are ineffective in increasing the survival rates of advanced staged patients by more than 5 years, OC has resulted in high morbidity and mortality rates over the last two decades. As a result, there is a dire need for innovative treatment approaches to address the issues. RNAi and nanotechnology can be considered the most appropriate strategies that can be used to improve OC therapy and help circumvent the chemo-resistance. siRNA is considered highly successful in facilitating the knockdown of specific genes on entering the cytosol when administered in-vivo via inhibiting the mRNA expression responsible for translation of those specific genes through the mechanism called RNA interference (RNAi). However, the primary barrier of utmost importance in the clinical efficacy of employed siRNA for the treatment of OC is the systemic distribution to the targeted site from the administration site. As a result, nanoparticles are constructed to carry the siRNA molecules inside them to the targeted site by preventing serum degradation and enhancing the serum stability of administered siRNA. The present review assesses the developments made in the polymeric-based nanoparticle siRNA delivery for targeting particular genes involved in the prognosis of ovarian cancers and surpassing the chemo-resistance and thus improving the therapeutic potentials of administered agents.

Non-apoptotic cell death in ovarian cancer: Treatment, resistance and prognosis

Ovarian cancer is mostly diagnosed at an advanced stage due to the absence of effective screening methods and specific symptoms. Repeated chemotherapy resistance and recurrence before PARPi are used as maintenance therapies, lead to low survival rates and poor prognosis. Apoptotic cell death plays a crucial role in ovarian cancer, which is proved by current researches. With the ongoing development of targeted therapy, non-apoptotic cell death has shown substantial potential in tumor prevention and treatment, including autophagy, ferroptosis, necroptosis, immunogenic cell death, pyroptosis, alkaliptosis, and other modes of cell death. We systematically reviewed the research progress on the role of non-apoptotic cell death in the onset, development, and outcome of ovarian cancer. This review provides a more theoretical basis for exploring therapeutic targets, reversing drug resistance in refractory ovarian cancer, and establishing risk prediction models that help realize the clinical transformation of vital drugs.

Potential toxicity of nanoparticles on the reproductive system animal models: A review

Over the past two decades, nanotechnology has been involved in an array of applications in various fields, including diagnostic kits, disease treatment, drug manufacturing, drug delivery, and gene therapy. But concerns about the toxicity of nanoparticles have greatly hindered their use; also, due to their increasing use in various industries, all members of society are exposed to the toxicity of these nanoparticles. Nanoparticles have a negative impact on various organs, including the reproductive system. They also can induce abortion in women, reduce fetal growth and development, and can damage the reproductive system and sperm morphology in men. In some cases, it has been observed that despite the modification of nanoparticles in composition, concentration, and method of administration, there is still damage to the reproductive organs. Therefore, understanding how nanoparticles affect the reproductive system is of very importance. In several studies, the nanoparticle toxicity effect on the genital organs has been investigated at the clinical and molecular levels using the in vivo and in vitro models. This study reviews these investigations and provides important data on the toxicity, hazards, and safety of nanoparticles in the reproductive system to facilitate the optimal use of nanoparticles in the industry.

Surface functionalization of zeolite-based drug delivery systems enhances their antitumoral activity in vivo

Zeolites have attractive features making them suitable carriers for drug delivery systems (DDS). As such, we loaded the anticancer drug 5-fluorouracil (5-FU), into two different zeolite structures, faujasite (NaY) and Linde Type L (LTL), to obtain different DDS. The prepared DDS were tested in vitro using breast cancer, colorectal carcinoma, and melanoma cell lines and in vivo using the chick embryo chorioallantoic membrane model (CAM). Both assays showed the best results for the Hs578T breast cancer cells, with a higher potentiation for 5-FU encapsulated in the zeolite LTL. To unveil the endocytic mechanisms involved in the internalization of the zeolite nanoparticles, endocytosis was inhibited pharmacologically in breast cancer and epithelial mammary human cells. The results suggest that a caveolin-mediated process was responsible for the internalized zeolite nanoparticles. Aiming to boost the DDS efficacy, the disc-shaped zeolite LTL outer surface was functionalized using amino (NH₂) or carboxylic acid (COOH) groups and coated with poly-l-lysine (PLL). Positively functionalized surface LTL nanoparticles revealed to be non-toxic to human cells and, importantly, their internalization was faster and led to a higher tumor reduction in vivo. Overall, our results provide further insights into the mechanisms of interaction between zeolite-based DDS and cancer cells, and pave the way for future studies aiming to improve DDS anticancer activity.

Cyclodextrin nanosponge for the GSH-mediated delivery of Resveratrol in human cancer cells

Smart drug delivery systems are required for the site-specific drug targeting to enhance the therapeutic efficiency of a drug. Resveratrol (RV) is a polyphenolic compound with anti-cancer activity. However, its poor aqueous solubility and non-selectivity are the major challenges for its employment in cancer therapy. In this work, we present the synthesis of RV-loaded glutathione responsive cyclodextrin nanosponges (RV-GSH-NSs) to improve the therapeutic efficiency and selective delivery of RV. The drug loading and encapsulation efficiency were 16.12% and 80.64%, respectively. The in vitro release profile confirmed that RV release was enhanced in response to external glutathione (GSH). Nude NSs were not toxic per se to human fibroblasts when administered for up to 72 h at the highest dose. Cell internalization studies confirmed that RV-GSH-NSs were preferentially up-taken by tumor cells compared to non-tumorigenic cells. Accordingly, RV showed selective toxicity to cancer cells compared to normal cells. GSH depletion by buthionine sulfoximine, a potent inhibitor of its synthesis, reflected in a significant decrease of the NSs accumulation, and consequently resulted in a drastic reduction of RV-mediated toxic effects in cancer cells. These findings demonstrate that GSH- responsive NSs represent an effective delivery system for targeting cancer cells by harnessing the differential tumor characteristics in terms of redox status in parallel with the limitation of side effects toward normal cells.

Nanotechnology in ovarian cancer: Diagnosis and treatment

To overcome the drawbacks of conventional delivery, this review spotlights a number of nanoscale drug delivery systems, including nanoparticles, liposomes, nano micelles, branched dendrimers, nanocapsules, and nanostructured lipid formulations for the targeted therapy of ovarian cancer. These nanoformulations offer numerous advantages to promote therapeutic drug delivery such as nontoxicity, biocompatibility, good biodegradability, increased therapeutic impact than free drugs, and non-inflammatory effects. Importantly, the development of specific ligands functionalized nanoformulations enable preferential targeting of ovarian tumors and eventually amplify the therapeutic potential compared to nonfunctionalized counterparts. Ovarian cancer is typically identified by biomarker assessment such as CA125, HE4, Mucin 1, and prostatic. There is, nevertheless, a tremendous demand for less costly, faster, and compact medical tools, both for timely detection and ovarian cancer control. This paper explored multiple types of tumor marker-based on nanomaterial biosensors. Initially, we mention different forms of ovarian cancer biomarkers involving CA125, human epididymis protein 4 (HE4), mucin 1 (MUC1), and prostate. It is accompanied by a brief description of new nanotechnology methods for diagnosis. Nanobiosensors for evaluating ovarian cancer biomarkers can be categorized based on electrochemical, optical, paper-based, giant magnetoresistive, and lab-on-a-chip devices.

Aqueous Suspensions of Cellulose Oligomer Nanoribbons for Growth and Natural Filtration-Based Separation of Cancer Spheroids

In vitro growth of cancer spheroids (CSs) and the subsequent separation of CSs from a 2D or 3D cell culture system are important for fundamental cancer studies and cancer drug screening. Although biopolymer-based or synthetic hydrogels are suitable candidates to be used as 3D cell culture scaffolds, alternatives with better processing capabilities are still required to set up cell culture microenvironment. In this study, we show that aqueous suspensions of crystalline nanoribbons composed of cellulose oligomers have a potential for CS growth and separation. The nanoribbon suspensions in serum-containing cell culture media fixed single cancer cells and CSs with large sizes in a 3D space, leading to suspension cultures for CS growth corresponding to culture time. Well-grown CSs were easily separated from the suspensions by natural filtration using a mesh filter with a suitable pore size. Cell viability tests revealed negligible cytotoxicity of the nanoribbons. In addition, physical damages to CSs by the separation procedures were negligible. Stable suspensions of biocompatible nanomaterials will thus provide novel microenvironments for growth and separation of diverse cell aggregates.

Toxicity comparison between pristine and sulfonate modified nanopolystyrene particles in affecting locomotion behavior, sensory perception, and neuronal development in Caenorhabditis elegans

Sulfonate modified polystyrene is potentially used in medical application; however, the effect of sulfonate modification on polystyrene toxicity is still largely unclear. We here compared the neurotoxicity between pristine and sulfonate modified nanopolystyrene particles in nematode Caenorhabditis elegans. Exposure to nanopolystyrene (35 nm) caused neurotoxicity on locomotion behaviors (head thrash, body bend, forward movement, and backward movement) and sensory perception behaviors (chemotaxis to NaCl or diacetyl). Exposure to nanopolystyrene also induced the damage on development of dopaminergic neurons as reflected by relative fluorescence intensity, number of discontinuous dendrite, and number of abnormal cell body. Moreover, we found that sulfonate modification effectively enhanced the neurontoxicity of nanopolystyrene on locomotion behaviors, sensory perception behaviors, and development of dopaminergic neurons. Our results highlight the possibility of sulfonate modification in increasing neurotoxicity of nanopolystyrene exposure on environmental organisms.