A bio-instructive parylene-based conformal coating suppresses thrombosis and intimal hyperplasia of implantable vascular devices.

Implantable vascular devices are widely used in clinical treatments for various vascular diseases. However, current approved clinical implantable vascular devices generally have high failure rates primarily due to their surface lacking inherent functional endothelium. Here, inspired by the pathological mechanisms of vascular device failure and physiological functions of native endothelium, we developed a new generation of bioactive parylene (poly(p-xylylene))-based conformal coating to address these challenges of the vascular devices. This coating used a polyethylene glycol (PEG) linker to introduce an endothelial progenitor cell (EPC) specific binding ligand LXW7 (cGRGDdvc) onto the vascular devices for preventing platelet adhesion and selectively capturing endogenous EPCs. Also, we confirmed the long-term stability and function of this coating in human serum. Using two vascular disease-related large animal models, a porcine carotid artery interposition model and a porcine carotid artery-jugular vein arteriovenous graft model, we demonstrated that this coating enabled rapid generation of self-renewable "living" endothelium on the blood contacting surface of the expanded polytetrafluoroethylene (ePTFE) grafts after implantation. We expect this easy-to-apply conformal coating will present a promising avenue to engineer surface properties of "off-the-shelf" implantable vascular devices for long-lasting performance in the clinical settings.

Intra- and inter-habitat variation in sediment heavy metals, antibiotics and ecological risks in Mai Po RAMSAR, China.

Distribution of heavy metals (HMs) and antibiotics (ABs) in surface sediments of three habitats: mudflat, mangrove and gei wai (inter-tidal shrimp ponds), at Mai Po RAMSAR were determined with inductively coupled plasma and liquid chromatograph tandem - mass spectrometry, respectively. Eight HMs (Cr, As, Pb, Cd, Mn, Ni, Cu and Zn), and ten ABs (tetracyclines, quinolones, macrolides and sulphonamides) were detected in all habitats, with relatively lower concentration in gei wai. Ecological risk assessment based on PNEC revealed that HMs posed a higher ecological risk to microorganisms than ABs. All metals except Mn were above their respective threshold effect levels according to sediment quality guidelines, indicating their potential toxicity to benthos. The enrichment factor and geo-accumulation index on background values suggested sediments were moderately polluted by Zn, Cu and Cd, possibly from anthropogenic inputs. This study implies that HMs pollution must be prevented through proper regulation of agricultural and industrial discharge.

Structure-Activity Relationship Study Identifies A Novel Lipophilic Amiloride Derivative That Induces Lysosome-Dependent Cell Death in Therapy-Resistant Breast Cancer Cells.

Amiloride and its derivatives have long attracted attention as potential anticancer therapeutic agents. Several early studies characterized amilorides as inhibitors of sodium-proton antiporter-dependent tumor growth and urokinase plasminogen activator-mediated metastasis. However, more recent observations indicate that amiloride derivatives are specifically cytotoxic toward tumor cells relative to normal cells and have the capacity to target tumor cell populations resistant to currently-employed therapies. A major barrier to clinical translation of the amilorides is their modest cytotoxic potency, with EC 50 values in the high micromolar to low millimolar range. Here we report structure-activity relationship observations that underscore the importance of the guanidinium group and the presence of lipophilic substituents at the C(5) position of the amiloride pharmacophore in promoting cytotoxicity. Moreover, we demonstrate that our most potent derivative called LLC1 is specifically cytotoxic toward mouse mammary tumor organoids and drug-resistant populations of various breast cancer cell lines, and induces lysosomal membrane permeabilization as a prelude to lysosome-dependent cell death. Our observations offer a roadmap for the future development of amiloride-based cationic amphiphilic drugs that engage the lysosome to specifically kill breast tumor cells.

Protocol for vision transformer-based evaluation of drug potency using images processed by an optimized Sobel operator.

Conventional approaches for screening anticancer drugs rely on chemical reactions, which are time consuming, labor intensive, and costly. Here, we present a protocol for label-free and high-throughput assessment of drug efficacy using a vision transformer and a Conv2D. We describe the steps for cell culture, drug treatment, data collection, and preprocessing. We then detail the building of deep learning models and their use to predict drug potency. This protocol can be adapted for screening chemicals that affect the density or morphological features of cells. For complete details on the use and execution of this protocol, please refer to Wang et al.1.

Discovery of Peptidic Ligands against the SARS-CoV-2 Spike Protein and Their Use in the Development of a Highly Sensitive Personal Use Colorimetric COVID-19 Biosensor.

In addition to efficacious vaccines and antiviral therapeutics, reliable and flexible in-home personal use diagnostics for the detection of viral antigens are needed for effective control of the COVID-19 pandemic. Despite the approval of several PCR-based and affinity-based in-home COVID-19 testing kits, many of them suffer from problems such as a high false-negative rate, long waiting time, and short storage period. Using the enabling one-bead-one-compound (OBOC) combinatorial technology, several peptidic ligands with a nanomolar binding affinity toward the SARS-CoV-2 spike protein (S-protein) were successfully discovered. Taking advantage of the high surface area of porous nanofibers, immobilization of these ligands on nanofibrous membranes allows the development of personal use sensors that can achieve low nanomolar sensitivity in the detection of the S-protein in saliva. This simple biosensor employing naked-eye reading exhibits detection sensitivity comparable to some of the current FDA-approved home detection kits. Furthermore, the ligand used in the biosensor was found to detect the S-protein derived from both the original strain and the Delta variant. The workflow reported here may enable us to rapidly respond to the development of home-based biosensors against future viral outbreaks.

SIC50: Determining drug inhibitory concentrations using a vision transformer and an optimized Sobel operator.

As a measure of cytotoxic potency, half-maximal inhibitory concentration (IC50) is the concentration at which a drug exerts half of its maximal inhibitory effect against target cells. It can be determined by various methods that require applying additional reagents or lysing the cells. Here, we describe a label-free Sobel-edge-based method, which we name SIC50, for the evaluation of IC50. SIC50 classifies preprocessed phase-contrast images with a state-of-the-art vision transformer and allows for the continuous assessment of IC50 in a faster and more cost-efficient manner. We have validated this method using four drugs and 1,536-well plates and also built a web application. We anticipate that this method will assist in the high-throughput screening of chemical libraries (e.g., small-molecule drugs, small interfering RNA [siRNA], and microRNA and drug discovery).

Engineered multi-functional, pro-angiogenic collagen-based scaffolds loaded with endothelial cells promote large deep burn wound healing.

The lack of vascularization associated with deep burns delays the construction of wound beds, increases the risks of infection, and leads to the formation of hypertrophic scars or disfigurement. To address this challenge, we have fabricated a multi-functional pro-angiogenic molecule by grafting integrin αvß3 ligand LXW7 and collagen-binding peptide (SILY) to a dermatan sulfate (DS) glycosaminoglycan backbone, named LXW7-DS-SILY (LDS), and further employed this to functionalize collagen-based Integra scaffolds. Using a large deep burn wound model in C57/BLK6 mice (8-10 weeks old, 26-32g, n = 39), we demonstrated that LDS-modified collagen-based Integra scaffolds loaded with endothelial cells (ECs) accelerate wound healing rate, re-epithelialization, vascularization, and collagen deposition. Specifically, a 2 cm × 3 cm full-thickness skin burn wound was created 48 h after the burn, and then wounds were treated with four groups of different dressing scaffolds, including Integra + ECs, Integra + LDS, and Integra + LDS + ECs with Integra-only as the control. Digital photos were taken for wound healing measurement on post-treatment days 1, 7, 14, 21, 28, and 35. Post-treatment photos revealed that treatment with the Intgera + LDS + ECs scaffold exhibited a higher wound healing rate in the proliferation phase. Histology results showed significantly increased re-epithelialization, increased collagen deposition, increased thin and mixed collagen fiber content, increased angiogenesis, and shorter wound length within the Integra + LDS + ECs group at Day 35. On Day 14, the Integra + LDS + ECs group showed the same trend. The relative proportions of collagen changed from Day 14 to Day 35 in the Integra + LDS + ECs and Integra + ECs groups demonstrated decreased thick collagen fiber deposition and greater thin and mixed collagen fiber deposition. LDS-modified Integra scaffolds represent a promising novel treatment to accelerate deep burn wound healing, thereby potentially reducing the morbidity associated with open burn wounds. These scaffolds can also potentially reduce the need for autografting and morbidity in patients with already limited areas of harvestable skin.

A bioactive material with dual integrin-targeting ligands regulates specific endogenous cell adhesion and promotes vascularized bone regeneration in adult and fetal bone defects.

Significant progress has been made in designing bone materials capable of directing endogenous cells to promote vascularized bone regeneration. However, current strategies lack regulation of the specific endogenous cell populations for vascularized bone regeneration, thus leading to adverse tissue formation and decreased regenerative efficiency. Here, we engineered a biomaterial to regulate endogenous cell adhesion and promote vascularized bone regeneration. The biomaterial works by presenting two synthetic ligands, LLP2A and LXW7, explicitly targeting integrins α4ß1 and αvß3, respectively, expressed on the surfaces of the cells related to bone formation and vascularization, such as mesenchymal stem cells (MSCs), osteoblasts, endothelial progenitor cells (EPCs), and endothelial cells (ECs). In vitro, the LLP2A/LXW7 modified biomaterial improved the adhesion of MSCs, osteoblasts, EPCs, and ECs via integrin α4ß1 and αvß3, respectively. In an adult rat calvarial bone defect model, the LLP2A/LXW7 modified biomaterial enhanced bone formation and vascularization by synergistically regulating endogenous cells with osteogenic and angiogenic potentials, such as DLX5+ cells, osteocalcin+ cells, CD34+/CD45- cells and CD31+ cells. In a fetal sheep spinal bone defect model, the LLP2A/LXW7 modified biomaterial augmented bone formation and vascularization without any adverse effects. This innovative biomaterial offers an off-the-shelf, easy-to-use, and biologically safe product suitable for vascularized bone regeneration in both fetal and adult disease environments.

Uses of Antibiotics in Ornamental Fish in Hong Kong and the Antibiotic Resistance in the Associated Zoonotic Pathogens.

The use of antibiotics in ornamental fish is not regulated, as they are not intended for human consumption. Although antibiotic resistant bacteria have been detected in ornamental fish worldwide, there have been no studies to look at the situation in Hong Kong. Therefore, the present study was conducted to investigate the use of antibiotics in ornamental fish. Ornamental fish were purchased from five local pet fish shops and the antibiotics in carriage water were quantified using liquid chromatography tandem mass spectrometry. Moreover, Aeromonas and Pseudomonas spp. present in carriage water were isolated and their minimum inhibitory concentrations against selected antibiotics were determined. Results indicated that among the twenty antibiotics screened, doxycycline (0.0155-0.0836 µg L-1), oxytetracycline (0.0102-29.0 µg L-1), tetracycline (0.0350-0.244 µg L-1), enrofloxacin (0.00107-0.247 µg L-1), and oxalinic acid (n.d.-0.514 µg L-1) were detected in all sampled shops. Additionally, MIC results revealed that some of the Aeromonas and Pseudomonas spp. isolates were highly resistant to all antibiotics selected. Our findings confirmed that multiple antibiotics are being used in ornamental fish and the associated bacteria are resistant to selected antibiotics, suggesting that this could be a significant transmission route of antibiotic resistant bacteria to household indoor environments.

Site-Specific Albumin-Selective Ligation to Human Serum Albumin under Physiological Conditions.

Human serum albumin (HSA) is the most abundant protein in human blood plasma. It plays a critical role in the native transportation of numerous drugs, metabolites, nutrients, and small molecules. HSA has been successfully used clinically as a noncovalent carrier for insulin (e.g., Levemir), GLP-1 (e.g., Liraglutide), and paclitaxel (e.g., Abraxane). Site-specific bioconjugation strategies for HSA only would greatly expand its role as the biocompatible, non-toxic platform for theranostics purposes. Using the enabling one-bead one-compound (OBOC) technology, we generated combinatorial peptide libraries containing myristic acid, a well-known binder to HSA at Sudlow I and II binding pockets, and an acrylamide. We then used HSA as a probe to screen the OBOC myristylated peptide libraries for reactive affinity elements (RAEs) that can specifically and covalently ligate to the lysine residue at the proximity of these pockets. Several RAEs have been identified and confirmed to be able to conjugate to HSA covalently. The conjugation can occur at physiological pH and proceed with a high yield within 1 h at room temperature. Tryptic peptide profiling of derivatized HSA has revealed two lysine residues (K225 and K414) as the conjugation sites, which is much more specific than the conventional lysine labeling strategy with N-hydroxysuccinimide ester. The RAE-driven site-specific ligation to HSA was found to occur even in the presence of other prevalent blood proteins such as immunoglobulin or whole serum. Furthermore, these RAEs are orthogonal to the maleimide-based conjugation strategy for Cys34 of HSA. Together, these attributes make the RAEs the promising leads to further develop in vitro and in vivo HSA bioconjugation strategies for numerous biomedical applications.

Nanoradiosensitizer with good tissue penetration and enhances oral cancer radiotherapeutic effect.

Low dose non-toxic disulfide cross-linked micelle (DCM) encapsulated paclitaxel (PTX) was found to be highly efficacious as a radiosensitizer against oral cancer preclinical model. Intensity-modulated radiation therapy was locally administered for three consecutive days 24 h after intravascular injection of DCM-[PTX] at 5 mg/kg PTX. DCM-[PTX] NPs combined with conventional radiotherapy (2 Gy) resulted in a 1.7-fold improvement in therapeutic efficacy compared to conventional PTX plus radiotherapy. Interestingly, we found that radiotherapy can decrease tight junctions and increase the accumulation of DCM-[PTX] in tumor sites. Stereotactic body radiotherapy (SBRT) given at 6 Gy was used to further investigate the synergistic anti-tumor effect. Tumor tissues were collected to analyze the relationship between the time interval after SBRT and the biodistribution of the nanomaterials. Compared to combination DCM-[PTX] with conventional radiation dose, combination DCM-PTX with SBRT was found to be more efficacious in inhibiting tumor growth.

MAIA, Fc receptor-like 3, supersedes JUNO as IZUMO1 receptor during human fertilization.

Gamete fusion is a critical event of mammalian fertilization. A random one-bead one-compound combinatorial peptide library represented synthetic human egg mimics and identified a previously unidentified ligand as Fc receptor-like 3, named MAIA after the mythological goddess intertwined with JUNO. This immunoglobulin super family receptor was expressed on human oolemma and played a major role during sperm-egg adhesion and fusion. MAIA forms a highly stable interaction with the known IZUMO1/JUNO sperm-egg complex, permitting specific gamete fusion. The complexity of the MAIA isotype may offer a cryptic sexual selection mechanism to avoid genetic incompatibility and achieve favorable fitness outcomes.

Bioinspired Screening of Anti-Adhesion Peptides against Blood Proteins for Intravenous Delivery of Nanomaterials.

Nanomaterials (NMs) inevitably adsorb proteins in blood and form "protein corona" upon intravenous administration as drug carriers, potentially changing the biological properties and intended functions. Inspired by anti-adhesion properties of natural proteins, herein, we employed the one-bead one-compound (OBOC) combinatorial peptide library method to screen anti-adhesion peptides (AAPs) against proteins. The library beads displaying random peptides were screened with three fluorescent-labeled plasma proteins. The nonfluorescence beads, presumed to have anti-adhesion property against the proteins, were isolated for sequence determination. These identified AAPs were coated on gold nanorods (GNRs), enabling significant extension of the blood circulating half-life of these GNRs in mice to 37.8 h, much longer than that (26.6 h) of PEG-coated GNRs. In addition, such AAP coating was found to alter the biodistribution profile of GNRs in mice. The bioinspired screening strategy and resulting peptides show great potential for enhancing the delivery efficiency and targeting ability of NMs.

Phototherapy with Cancer-Specific Nanoporphyrin Potentiates Immunotherapy in Bladder Cancer.

PURPOSE: Immune checkpoint inhibitors (ICI) in general have shown poor efficacy in bladder cancer. The purpose of this project was to determine whether photodynamic therapy (PDT) with bladder cancer-specific porphyrin-based PLZ4-nanoparticles (PNP) potentiated ICI. EXPERIMENTAL DESIGN: SV40 T/Ras double-transgenic mice bearing spontaneous bladder cancer and C57BL/6 mice carrying syngeneic bladder cancer models were used to determine the efficacy and conduct molecular correlative studies. RESULTS: PDT with PNP generated reactive oxygen species, and induced protein carbonylation and dendritic cell maturation. In SV40 T/Ras double-transgenic mice carrying spontaneous bladder cancer, the median survival was 33.7 days in the control, compared with 44.8 (P = 0.0123), 52.6 (P = 0.0054), and over 75 (P = 0.0001) days in the anti-programmed cell death-1 antibody (anti-PD-1), PNP PDT, and combination groups, respectively. At Day 75 when all mice in other groups died, only 1 in 7 mice in the combination group died. For the direct anti-tumor activity, compared with the control, the anti-PD-1, PNP PDT, and combination groups induced a 40.25% (P = 0.0003), 80.72% (P < 0.0001), and 93.03% (P < 0.0001) tumor reduction, respectively. For the abscopal anticancer immunity, the anti-PD-1, PNP PDT, and combination groups induced tumor reduction of 45.73% (P = 0.0001), 54.92% (P < 0.0001), and 75.96% (P < 0.0001), respectively. The combination treatment also diminished spontaneous and induced lung metastasis. Potential of immunotherapy by PNP PDT is multifactorial. CONCLUSIONS: In addition to its potential for photodynamic diagnosis and therapy, PNP PDT can synergize immunotherapy in treating locally advanced and metastatic bladder cancer. Clinical trials are warranted to determine the efficacy and toxicity of this combination.

Engineered extracellular vesicles with high collagen-binding affinity present superior in situ retention and therapeutic efficacy in tissue repair.

Although stem cell-derived extracellular vesicles (EVs) have remarkable therapeutic potential for various diseases, the therapeutic efficacy of EVs is limited due to their degradation and rapid diffusion after administration, hindering their translational applications. Here, we developed a new generation of collagen-binding EVs, by chemically conjugating a collagen-binding peptide SILY to EVs (SILY-EVs), which were designed to bind to collagen in the extracellular matrix (ECM) and form an EV-ECM complex to improve EVs' in situ retention and therapeutic efficacy after transplantation. Methods: SILY was conjugated to the surface of mesenchymal stem/stromal cell (MSC)-derived EVs by using click chemistry to construct SILY-EVs. Nanoparticle tracking analysis (NTA), ExoView analysis, cryogenic electron microscopy (cryo-EM) and western-blot analysis were used to characterize the SILY-EVs. Fluorescence imaging (FLI), MTS assay, ELISA and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to evaluate the collagen binding and biological functions of SILY-EVs in vitro. In a mouse hind limb ischemia model, the in vivo imaging system (IVIS), laser doppler perfusion imaging (LDPI), micro-CT, FLI and RT-qPCR were used to determine the SILY-EV retention, inflammatory response, blood perfusion, gene expression, and tissue regeneration. Results:In vitro, the SILY conjugation significantly enhanced EV adhesion to the collagen surface and did not alter the EVs' biological functions. In the mouse hind limb ischemia model, SILY-EVs presented longer in situ retention, suppressed inflammatory responses, and significantly augmented muscle regeneration and vascularization, compared to the unmodified EVs. Conclusion: With the broad distribution of collagen in various tissues and organs, SILY-EVs hold promise to improve the therapeutic efficacy of EV-mediated treatment in a wide range of diseases and disorders. Moreover, SILY-EVs possess the potential to functionalize collagen-based biomaterials and deliver therapeutic agents for regenerative medicine applications.

Programmable Bispecific Nano-immunoengager That Captures T Cells and Reprograms Tumor Microenvironment.

Immune checkpoint blockade (ICB) therapy has revolutionized clinical oncology. However, the efficacy of ICB therapy is limited by the ineffective infiltration of T effector (Teff) cells to tumors and the immunosuppressive tumor microenvironment (TME). Here, we report a programmable tumor cells/Teff cells bispecific nano-immunoengager (NIE) that can circumvent these limitations to improve ICB therapy. The peptidic nanoparticles (NIE-NPs) bind tumor cell surface α3ß1 integrin and undergo in situ transformation into nanofibrillar network nanofibers (NIE-NFs). The prolonged retained nanofibrillar network at the TME captures Teff cells via the activatable α4ß1 integrin ligand and allows sustained release of resiquimod for immunomodulation. This bispecific NIE eliminates syngeneic 4T1 breast cancer and Lewis lung cancer models in mice, when given together with anti-PD-1 antibody. The in vivo structural transformation-based supramolecular bispecific NIE represents an innovative class of programmable receptor-mediated targeted immunotherapeutics to greatly enhance ICB therapy against cancers.

Discovery and Characterization of a Potent Antifungal Peptide through One-Bead, One-Compound Combinatorial Library Screening.

This work describes the discovery of a bead-bound membrane-active peptide (MAP), LBF127, that selectively binds fungal giant unilamellar vesicles (GUVs) over mammalian GUVs. LBF127 was re-synthesized in solution form and demonstrated to have antifungal activity with limited hemolytic activity and cytotoxicity against mammalian cells. Through systematic structure-activity relationship studies, including N- and C-terminal truncation, alanine-walk, and d-amino acid substitution, an optimized peptide, K-oLBF127, with higher potency, less hemolytic activity, and cytotoxicity emerged. Compared to the parent peptide, K-oLBF127 is shorter by three amino acids and has a lysine at the N-terminus to confer an additional positive charge. K-oLBF127 was found to have improved selectivity toward the fungal membrane over mammalian membranes by 2-fold compared to LBF127. Further characterizations revealed that, while K-oLBF127 exhibits a spectrum of antifungal activity similar to that of the original peptide, it has lower hemolytic activity and cytotoxicity against mammalian cells. Mice infected with Cryptococcus neoformans and treated with K-oLBF127 (16 mg/kg) for 48 h had significantly lower lung fungal burden compared to untreated animals, consistent with K-oLBF127 being active in vivo. Our study demonstrates the success of the one-bead, one-compound high-throughput strategy and sequential screening at identifying MAPs with strong antifungal activities.

The Role of Adjuvant Single Postoperative Instillation of Gemcitabine for Non-Muscle-Invasive Bladder Cancer: A Systematic Review and Meta-Analysis.

Bladder cancer is a heterogeneous disease with variable natural history. Non-muscle-invasive bladder cancer has a favorable prognosis following transurethral resection, but the optimal adjuvant chemotherapy plan is still in debate. The aim of this study was to evaluate the effect of the adjuvant intravesical administration of a single dose of gemcitabine in the outcome of this disease. For that purpose, we performed a systematic review and meta-analysis on available randomized control trials on MEDLINE, EMBASE, Cochrane, Scopus, and Google Scholar databases. Ultimately, two studies were included with a total number of 654 patients. The statistical analysis performed showed that a single post-operative intravesical dose of gemcitabine does not affect the recurrence rate of non-muscle-invasive bladder cancer compared to placebo. Therefore, this therapeutic strategy does not offer any significant improvement on the outcomes of the disease. Nonetheless, due to the plethora of available therapeutic agents and treatment strategies, further research is needed to establish the optimal treatment in this category of patients.

Joint Effects of Cigarette Smoking and Green Tea Consumption with miR-29b and DNMT3B mRNA Expression in the Development of Lung Cancer.

In tumor development, increased expression of DNA methyltransferase (DNMT) has been observed. In particular, cigarette smoke and tea polyphenols may influence DNMT3B mRNA expression by regulating microRNA (miR)-29b expression. Herein, we designed a case−control study to evaluate the joint effects of smoking and green tea consumption, with miR-29b and DNMT3B mRNA expression, in lung cancer development. A total of 132 lung cancer patients and 132 healthy controls were recruited to measure miR-29b and DNMT3B mRNA expression in whole blood. Results revealed that lung cancer patients had lower miR-29b expression (57.2 vs. 81.6; p = 0.02) and higher DNMT3B mRNA expression (37.2 vs. 25.8; p < 0.001) than healthy controls. Compared to non-smokers with both higher miR-29b and lower DNMT3B mRNA expression, smokers with both low miR-29b and higher DNMT3B mRNA expression had an elevated risk of lung cancer development (OR 5.12, 95% CI 2.64−9.91). Interactions of smoking with miR-29b or DNMT3B mRNA expression in lung cancer were significant. Interaction of green tea consumption with miR-29b expression and DNMT3B mRNA expression in lung cancer was also significant. Our study suggests that smokers and green tea nondrinkers with lower miR-29b expression and higher DNMT3B mRNA expression are more susceptible to lung cancer development.

Targeting Epigenetic Modifiers of Tumor Plasticity and Cancer Stem Cell Behavior.

Tumor heterogeneity poses one of the greatest challenges to a successful treatment of cancer. Tumor cell populations consist of different subpopulations that have distinct phenotypic and genotypic profiles. Such variability poses a challenge in successfully targeting all tumor subpopulations at the same time. Relapse after treatment has been previously explained using the cancer stem cell model and the clonal evolution model. Cancer stem cells are an important subpopulation of tumor cells that regulate tumor plasticity and determine therapeutic resistance. Tumor plasticity is controlled by genetic and epigenetic changes of crucial genes involved in cancer cell survival, growth and metastasis. Targeting epigenetic modulators associated with cancer stem cell survival can unlock a promising therapeutic approach in completely eradicating cancer. Here, we review various factors governing epigenetic dysregulation of cancer stem cells ranging from the role of epigenetic mediators such as histone and DNA methyltransferases, histone deacetylases, histone methyltransferases to various signaling pathways associated with cancer stem cell regulation. We also discuss current treatment regimens targeting these factors and other promising inhibitors in clinical trials.