Emerging Strategies in Mesenchymal Stem Cell-Based Cardiovascular Therapeutics.

Cardiovascular diseases continue to challenge global health, demanding innovative therapeutic solutions. This review delves into the transformative role of mesenchymal stem cells (MSCs) in advancing cardiovascular therapeutics. Beginning with a historical perspective, we trace the development of stem cell research related to cardiovascular diseases, highlighting foundational therapeutic approaches and the evolution of cell-based treatments. Recognizing the inherent challenges of MSC-based cardiovascular therapeutics, which range from understanding the pro-reparative activity of MSCs to tailoring patient-specific treatments, we emphasize the need to refine the pro-regenerative capacity of these cells. Crucially, our focus then shifts to the strategies of the fourth generation of cell-based therapies: leveraging the secretomic prowess of MSCs, particularly the role of extracellular vesicles; integrating biocompatible scaffolds and artificial sheets to amplify MSCs' potential; adopting three-dimensional ex vivo propagation tailored to specific tissue niches; harnessing the promise of genetic modifications for targeted tissue repair; and institutionalizing good manufacturing practice protocols to ensure therapeutic safety and efficacy. We conclude with reflections on these advancements, envisaging a future landscape redefined by MSCs in cardiovascular regeneration. This review offers both a consolidation of our current understanding and a view toward imminent therapeutic horizons.

Differential Expression of Non-Coding RNAs in Stem Cell Development and Therapeutics of Bone Disorders.

Stem cells' self-renewal and multi-lineage differentiation are regulated by a complex network consisting of signaling factors, chromatin regulators, transcription factors, and non-coding RNAs (ncRNAs). Diverse role of ncRNAs in stem cell development and maintenance of bone homeostasis have been discovered recently. The ncRNAs, such as long non-coding RNAs, micro RNAs, circular RNAs, small interfering RNA, Piwi-interacting RNAs, etc., are not translated into proteins but act as essential epigenetic regulators in stem cells' self-renewal and differentiation. Different signaling pathways are monitored efficiently by the differential expression of ncRNAs, which function as regulatory elements in determining the fate of stem cells. In addition, several species of ncRNAs could serve as potential molecular biomarkers in early diagnosis of bone diseases, including osteoporosis, osteoarthritis, and bone cancers, ultimately leading to the development of new therapeutic strategies. This review aims to explore the specific roles of ncRNAs and their effective molecular mechanisms in the growth and development of stem cells, and in the regulation of osteoblast and osteoclast activities. Furthermore, we focus on and explore the association of altered ncRNA expression with stem cells and bone turnover.

Enhanced Targeted Delivery of Minocycline via Transferrin Conjugated Albumin Nanoparticle Improves Neuroprotection in a Blast Traumatic Brain Injury Model.

Traumatic brain injury (TBI) is a major source of death and disability worldwide as a result of motor vehicle accidents, falls, attacks and bomb explosions. Currently, there are no FDA-approved drugs to treat TBI patients predominantly because of a lack of appropriate methods to deliver drugs to the brain for therapeutic effect. Existing clinical and pre-clinical studies have shown that minocycline's neuroprotective effects either through high plasma protein binding or an increased dosage requirement have resulted in neurotoxicity. In this study, we focus on the formulation, characterization, in vivo biodistribution, behavioral improvements, neuroprotective effect and toxicity of transferrin receptor-targeted (tf) conjugated minocycline loaded albumin nanoparticles in a blast-induced TBI model. A novel tf conjugated minocycline encapsulated albumin nanoparticle was developed, characterized and quantified using a validated HPLC method as well as other various analytical methods. The results of the nanoformulation showed small, narrow hydrodynamic size distributions, with high entrapment, loading efficiencies and sustained release profiles. Furthermore, the nanoparticle administered at minimal doses in a rat model of blast TBI was able to cross the blood-brain barrier, enhanced nanoparticle accumulation in the brain, improved behavioral outcomes, neuroprotection, and reduced toxicity compared to free minocycline. Hence, tf conjugated minocycline loaded nanoparticle elicits a neuroprotective effect and can thus offer a potential therapeutic effect.

GSTs genetic polymorphism, gene-environment interaction and association with gallbladder cancer risk in North Indian population: A case-controlled study.

AIM: In the present case-controlled study, we explored the role of genetic polymorphism in three xenobiotic metabolizing genes, GSTM1, GSTT1 and GSTP1, and their association to gallbladder cancer (GBC) risk in a North Indian population. Its etiology is influenced by genetic, food habits, lifestyle, and environmental factors. GBC incidence is significantly higher in the Gangetic belt, India. Therefore, we explored the prognostic factors in the susceptibility of GBC through gene-gene and gene-environment interaction in this region. MATERIAL AND METHODS: Genetic polymorphism was analyzed in 108 GBC patients from Kamala Nehru Memorial Cancer Hospital, Prayagraj and 142 matched controls. GSTM1 and GSTT1 genotypes were analyzed by multiplex PCR method, while restriction fragment length polymorphism (RFLP) was performed to analyze GSTP1 genotypes. Logistic regression analysis calculating the odds ratio (OR) and 95% confidence interval (CI) was performed to analyze the GBC risk. RESULTS: GSTT1 (null) genotype was at a significantly higher risk and susceptible to GBC (OR = 2.044, CI = 1.225-3.411, P = 0.006), while GSTM1 and GSTP1 genotypes did not show any association to GBC risk. After sex stratification, females diagnosed with GBC had higher GSTT1 (null) genotype (OR = 2.754, CI = 1.428-5.310, P = 0.003) compared to males. GBC patients dwelling in rural areas show higher GSTT1 (null) genotype with two-fold GBC risk (OR = 2.031, CI = 1.200-3.439, P = 0.008). Further, GBC patients with histopathology of adenocarcinoma also showed higher GSTT1 (null) genotype (OR = 2.113, CI = 1.248-3.578, P = 0.005). Gene-gene interaction between GSTT1 (non-null)/GSTP1 (Ile/Val + Val/Val), enhance the GBC risk (OR = 1.840, CI = 1.135-2.982, P = 0.013). CONCLUSIONS: The present study suggests that GSTT1 (null) genotype has higher susceptibility and risk towards GBC in North Indian population. Female patients, patients with histopathology of adenocarcinoma and rural dwelling GBC patients have higher GSTT1 (null) genotypes and may be at risk of developing GBC. The genotype combination GSTT1 (non-null)/GSTP1 (Ile/Val + Val/Val) has increased GBC susceptibility and may be considered as 'at risk' genotypes for GBC in North Indians.

Metabolic Pathways, Enzymes, and Metabolites: Opportunities in Cancer Therapy.

Metabolic reprogramming enables cancer cells to proliferate and produce tumor biomass under a nutrient-deficient microenvironment and the stress of metabolic waste. A cancer cell adeptly undergoes a variety of adaptations in metabolic pathways and differential expression of metabolic enzyme genes. Metabolic adaptation is mainly determined by the physiological demands of the cancer cell of origin and the host tissue. Numerous metabolic regulators that assist cancer cell proliferation include uncontrolled anabolism/catabolism of glucose metabolism, fatty acids, amino acids metabolism, nucleotide metabolism, tumor suppressor genes, microRNAs, and many regulatory enzymes and genes. Using this paradigm, we review the current understanding of metabolic reprogramming in tumors and discuss the new strategies of cancer metabolomics that can be tapped into for cancer therapeutics.

Nanoformulations - Insights Towards Characterization Techniques.

BACKGROUND: Drug-loaded novel nanoformulations are gaining importance due to their versatile properties compared to conventional pharmaceutical formulations. Nanomaterials, apart from their multifactorial benefits, have a wider scope in the prevention, treatment, and diagnosis of cancer. Understanding the chemistry of drug-loaded nano-formulations to elicit its behaviour both at molecular and systemic levels is critical in the present scenario. Drug-loaded nanoformulations are controlled by their size, shape, surface chemistry, and release behavior. The major pharmaceutical drug loaded nanocarriers reported for anticancer drug delivery for the treatment of various forms of cancers such as lung cancer, liver cancer, breast cancer, colon cancer, etc include nanoparticles, nanospheres, nanodispersions, nanocapsules, nanomicelles, cubosomes, nanoemulsions, liposomes and niosomes. The major objectives in designing anticancer drug-loaded nanoformulations are to manage the particle size/morphology correlating with the drug release to fulfil the specific objectives. Hence, nano characterizations are very critical both at in vitro and in vivo levels. OBJECTIVE: The main objective of this review paper is to summarise the major characterization techniques used for the characterization of drug-loaded nanoformulations. Even though information on characterization techniques of various nano-formulations is available in the literature, it is scattered. The proposed review will provide a comprehensive understanding of nanocharacterization techniques. CONCLUSION: To conclude, the proposed review will provide insights towards the different nano characterization techniques along with their recent updates, such as particle size, zeta potential, entrapment efficiency, in vitro release studies (chromatographic HPLC, HPTLC, and LC-MS/MS analysis), EPR analysis, X-ray diffraction analysis, thermal analysis, rheometric, morphological analysis etc. Additionally, the challenges encountered by the nano characterization techniques will also be discussed.

An open label randomized clinical trial of Indomethacin for mild and moderate hospitalised Covid-19 patients.

Indomethacin, a non-steroidal anti-inflammatory drug (NSAID), has been presented as a broad-spectrum antiviral agent. This randomised clinical trial in a hospital setting evaluated the efficacy and safety of this drug in RT-PCR-positive coronavirus disease 2019 (COVID-19) patients. A total of 210 RT-PCR-positive COVID-19 patients who provided consent were allotted to the control or case arm, based on block randomisation. The control arm received standard of care comprising paracetamol, ivermectin, and other adjuvant therapies. The patients in the case arm received indomethacin instead of paracetamol, with other medications retained. The primary endpoint was the development of hypoxia/desaturation with SpO2 ≤ 93, while time to become afebrile and time for cough and myalgia resolution were the secondary endpoints. The results of 210 patients were available, with 103 and 107 patients in the indomethacin and paracetamol arms, respectively. We monitored patient profiles along with everyday clinical parameters. In addition, blood chemistry at the time of admission and discharge was assessed. As no one in either of the arms required high-flow oxygen, desaturation with a SpO2 level of 93 and below was the vital goal. In the indomethacin group, none of the 103 patients developed desaturation. On the other hand, 20 of the 107 patients in the paracetamol arm developed desaturation. Patients who received indomethacin also experienced more rapid symptomatic relief than those in the paracetamol arm, with most symptoms disappearing in half the time. In addition, 56 out of 107 in the paracetamol arm had fever on the seventh day, while no patient in the indomethacin group had fever. Neither arm reported any adverse event. The fourteenth-day follow-up revealed that the paracetamol arm patients had faced several discomforts; indomethacin arm patients mostly complained only of tiredness. Indomethacin is a safe and effective drug for treating patients with mild and moderate covid-19.

Clinical response of carboplatin-based chemotherapy and its association to genetic polymorphism in lung cancer patients from North India - A clinical pharmacogenomics study.

Purpose: Lung cancer mostly diagnosed at advanced inoperable stages; thereby, the chemo-, radiation-, targeted or immune-therapy alone or in combination remains the treatment of choice. In chemotherapy, platinum-based compounds such as cisplatin and carboplatin and third-generation drugs such as docetaxel, paclitaxel, gemcitabine, and vinorelbine are widely used. The beneficial therapeutic outcome of the chemotherapy alone or in combination with radiation (chemoradiation) and/or development of drug resistance depends on the inter-individual genetic differences. Hence, this study was carried out to find gene biomarker that could be useful in the diagnosis of the disease and to predict the outcome of chemo/chemoradiation therapy in ethnic North Indian population. Materials and Methods: In this clinical study, lung cancer (n = 52) patients from North Indian population were recruited. All the patients were treated with carboplatin target area under curve-5 in combination with third-generation drugs (gemcitabine 1.2 mg/m2; paclitaxel 175 mg/m2; and etopside 100 mg/m2) and radiation therapy. The genomic DNA was isolated from the blood sample and performed polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. Results: We found hazard ratio to be significantly higher for XPDLys751Gln (hazard ratio [HR] =2.11, 95% confidence interval [CI]: 0.98-4.53, P = 0.056) and IL1 ß511C/T (HR = 9.9, 95% CI: 2.55-38.40, P = 0.001). GSTT1 null (HR = 0.39, 95%CI: 0.18-0.84, P = 0.017) genotype has better response to chemotherapy. Generalized multidimensional reduction model suggested that IL1RN (cross-validation consistency [CVC] =10/10, P = 0.054) and XRCC1399Gln, GSTM1 (CVC = 10/10, P = 0.001) as best predicted model in lung cancer patients to the treatment response. Conclusion: Genetic polymorphisms and single nucleotide polymorphisms in DNA repair gene (XRCC1, XPD) and drug-metabolizing gene (GSTM1 and GSTT1) could serve as genetic biomarkers in lung cancer patients treated with the above indicated chemotherapy. Based on genotype and chemotherapy treatments, the toxicity effects can be minimized, this will help in the development of personalized medicine in future with better efficacy.

Arginine-Modified Polymers Facilitate Poly (Lactide-Co-Glycolide)-Based Nanoparticle Gene Delivery to Primary Human Astrocytes.

PURPOSE: Astrocyte dysfunction is a hallmark of central nervous system injury or infection. As a primary contributor to neurodegeneration, astrocytes are an ideal therapeutic target to combat neurodegenerative conditions. Gene therapy has arisen as an innovative technique that provides excellent prospect for disease intervention. Poly (lactide-co-glycolide) (PLGA) and polyethylenimine (PEI) are polymeric nanoparticles commonly used in gene delivery, each manifesting their own set of advantages and disadvantages. As a clinically approved polymer by the Federal Drug Administration, well characterized for its biodegradability and biocompatibility, PLGA-based nanoparticles (PLGA-NPs) are appealing for translational gene delivery systems. However, our investigations revealed PLGA-NPs were ineffective at facilitating exogenous gene expression in primary human astrocytes, despite their success in other cell lines. Furthermore, PEI polymers illustrate high delivery efficiency but induce cytotoxicity. The purpose of this study is to develop viable and biocompatible NPsystem for astrocyte-targeted gene therapy. MATERIALS AND METHODS: Successful gene expression by PLGA-NPs alone or in combination with arginine-modified PEI polymers (AnPn) was assessed by a luciferase reporter gene encapsulated in PLGA-NPs. Cytoplasmic release and nuclear localization of DNA were investigated using fluorescent confocal imaging with YOYO-labeled plasmid DNA (pDNA). NP-mediated cytotoxicity was assessed via lactate dehydrogenase in primary human astrocytes and neurons. RESULTS: Confocal imaging of YOYO-labeled pDNA confirmed PLGA-NPs delivered pDNA to the cytoplasm in a dose and time-dependent manner. However, co-staining revealed pDNA delivered by PLGA-NPs did not localize to the nucleus. The addition of AnPn significantly improved nuclear localization of pDNA and successfully achieved gene expression in primary human astrocytes. Moreover, these formulations were biocompatible with both astrocytes and neurons. CONCLUSION: By co-transfecting two polymeric NPs, we developed an improved system for gene delivery and expression in primary human astrocytes. These findings provide a basis for a biocompatible and clinically translatable method to regulate astrocyte function during neurodegenerative diseases and disorders.

Synergistic combination treatment to break cross talk between cancer cells and bone cells to inhibit progression of bone metastasis.

Advanced-stage cancers often metastasize to bone, and is the major cause of cancer-related morbidity and mortality. Due to poor biodistribution of intravenously administered anticancer drugs within the bone, chemotherapy is not optimally effective in treating bone metastasis. Additionally, overexpression of receptor activator of nuclear factor κB ligand (RANKL) in the bone microenvironment drives the vicious, destructive cycle of progression of bone metastasis and bone resorption. We hypothesized that the combination treatment - with docetaxel (TXT), an anticancer drug encapsulated in sustained release biodegradable nanoparticles (TXT-NPs) that are designed to localize in bone marrow, and denosumab monoclonal antibody (DNmb), which binds to RANKL - could be more effective than either treatment alone. We tested our hypothesis in intraosseous prostate cancer (PC-3) cell-induced osteolytic mouse model of bone metastasis with treatments given intravenously. The results demonstrated better efficacy with TXT-NPs than with TXT-CrEL or saline control in inhibiting progression of metastasis and improving survival. TXT-NPs showed ~3-fold higher drug levels in metastasized bone tissue at 1 wk post-administration than TXT-CrEL, thus explaining their efficacy. However, the combination treatment (TXT-NPs + DNmb) given simultaneously was significantly more effective in inhibiting metastatic progression; it caused early tumor regression and improved survival, and caused no body weight loss or tumor relapse, even when the treatment was discontinued, whereas TXT-NPs or DNmb alone treatments showed tumor relapse after an initial regression. Micro-CT analysis of the bone from the combination treatment showed no bone loss and normal bone mineral content, bone density, and bone volume fraction, whereas TXT-NPs or DNmb alone treatments showed bone loss. Confirming the above results, histochemical analysis of the bone from the combination treatment demonstrated normal bone morphology, and osteoblast and osteoclast cell activities. In conclusion, TXT-NPs and DNmb in combination, because of their complementary roles in breaking the cross talk between cancer cells and bone cells, was significantly effective in treating bone metastasis.

Near infra-red polymeric nanoparticle based optical imaging in Cancer diagnosis.

Cancer disease is a foremost health concern and top basis of death in comparison with many diseases including cardiovascular disorders. During initial diagnosis (usually late diagnosis), a majority of cancer patients suffer from metastatic and advanced cancer stages which resulted in limited therapeutic modalities based interventions and effectiveness. Though considerable advancement has been made in combating the disease, continuous and intense efforts are ongoing for early diagnosis and development of therapies. Generally applied treatment options for cancer are surgery, chemotherapy and radiotherapy, which are restricted by failure to early diagnose, insufficient on-targeted drug delivery, systemic toxicity, and lack of real-time monitoring of therapeutic responses in cancer. Noninvasive imaging or minimally invasive imaging methodology is valuable in clinical diagnostic settings. Specifically, noninvasive optical imaging integrated with polymeric nanomaterial have been extensively investigated in the field of cancer diagnostics and therapy. Currently, optical imaging methods go together with polymer-based fluorescent nanoparticles in accomplishing the molecular level detection of tumor boundaries. NIR probe tagged polymeric nanoparticles have potential to provide an advantage in the early cancer detection, therapeutic monitoring and image guided surgery procedures. This article review the recent progress in state-of-the-art NIRF polymeric nanoparticles used for optical imaging particularly on cancer diagnosis.

Genetic Polymorphisms of Xenobiotic Metabolizing Genes (GSTM1, GSTT1, GSTP1), Gene-Gene Interaction with Association to Lung Cancer Risk in North India; A Case Control Study.

Aim: In this case control study involving, 220 human subjects; polymorphisms in xenobiotic metabolizing genes (GST-M1, -T1 and -P1) and their association to lung cancer risk is being analysed among smokers and nonsmokers. GSTM1 or GSTT1 gene polymorphism and amino acid changes in GSTP1 have been correlated and may be associated to lung cancer risk. Other factor includes exposure to environmental pollutants and life style choices. We have explored gene-gene and gene-environment interaction in the aetiology of lung cancer risk among north Indian population. Patients and Methods: For the study we have collected 120 lung cancer patient blood samples from Kamala Nehru Memorial Cancer Hospital, Allahabad, Uttar Pradesh and 100 matched controls. DNA was isolated and GST-M1 and - T1 genotyping were assessed by multiplex PCR whereas the GSTP1 polymorphism was analysed using restriction fragment length polymorphism. The risk of lung carcinogenesis was assessed using logistic regression analysis calculating the odd ratio (OR) with 95% confidence interval (CI). Results: The risk of lung carcinogenesis was three fold higher for null GSTT1 (OR=3.045, 95%CI=1.750-5.301, p-value <0.001) genotype; whereas other two types; GSTM1 (OR= 1.342, 95% CI=0.788-2.284, p-value=0.270) and GSTP1 (OR=0.806, 95% CI=0.526-1.236, p-value=0.323) showed no association to lung cancer susceptibility respectively. Smokers diagnosed with lung cancer had more null genotypes for GSTT1 (OR=4.773, 95%CI=1.939-11.751, p<0.001). The 'at risk' genotype combination GSTM1 (null) /GSTT1 (null) (OR=1.76, 95%CI; 0.920-3.370, p-value=0.03) showed increased susceptibility to lung cancer risk. The genotype combination of GSTT1 (null)/GSTP1 (Ile/Ile) (p=0.009) was associated with increased lung cancer risk. Conclusion: The results of this study suggest that; GSTT1 null genotype were more susceptible for lung cancer risk and smoking increases the susceptibility for lung cancer several folds among the North Indian population. Gene-gene interaction for null genotypes of GSTM1 and GSTT1 were correlated with higher risk of having lung cancer.

Evaluating accessibility of intravenously administered nanoparticles at the lesion site in rat and pig contusion models of spinal cord injury.

In spinal cord injury (SCI), timely therapeutic intervention is critical to inhibit the post-injury rapidly progressing degeneration of spinal cord. Towards that objective, we determined the accessibility of intravenously administered biodegradable nanoparticles (NPs) as a drug delivery system to the lesion site in rat and pig contusion models of SCI. Poly (d,l-lactide co-glycolide, PLGA)-based NPs loaded with a near-infrared dye as a marker for NPs were used. To analyze and quantify localization of NPs to the lesion site, we mapped the entire spinal cord, segment-by-segment, for the signal count. Our objectives were to determine the NP dose effect and duration of retention of NPs at the lesion site, and the time window post-SCI within which NPs localize at the lesion site. We hypothesized that breakdown of the blood-spinal cord barrier following contusion injury could lead to more specific localization of NPs at the lesion site. The mapping data showed a dose-dependent increase and significantly greater localization of NPs at the lesion site than in the remaining uninjured segment of the spinal cord. Further, NPs were seen to be retained at the lesion site for more than a week. With delayed post-SCI administration, localization of NPs at the lesion site was reduced but still localize even at four weeks post-injury administration. Interestingly, in uninjured animals (sham control), greater accumulation of NPs was seen in the thoracic and lumbar enlargement regions of the spinal cord, which in animals with SCI changed to the lesion site, indicating drastic post-injury hemodynamic changes in the spinal cord. Similar to the rat results, pig contusion model of SCI showed greater NP localization at the lesion site. In conclusion, NPs could potentially be explored as a carrier for delivery of therapeutics to the lesion site to minimize the impact of post-SCI response.

Reaching for the Stars in the Brain: Polymer-Mediated Gene Delivery to Human Astrocytes.

Astrocytes, the "star-shaped" glial cells, are appealing gene-delivery targets to treat neurological diseases due to their diverse roles in brain homeostasis and disease. Cationic polymers have successfully delivered genes to mammalian cells and hence present a viable, non-immunogenic alternative to widely used viral vectors. In this study, we investigated the gene delivery potential of a series of arginine- and polyethylene glycol-modified, siloxane-based polyethylenimine analogs in primary cultured human neural cells (neurons and astrocytes) and in mice. Plasmid DNAs encoding luciferase reporter were used to measure gene expression. We hypothesized that polyplexes with arginine would help in cellular transport of the DNA, including across the blood-brain barrier; polyethylene glycol will stabilize polyethylenimine and reduce its toxicity while maintaining its DNA-condensing ability. Polyplexes were non-toxic to human neural cells and red blood cells. Cellular uptake of polyplexes and sustained gene expression were seen in human astrocytes as well as in mouse brains post-intravenous-injections. The polyplexes also delivered and expressed genes driven by astrocyte-restricted glial fibrillary acidic protein promoters, which are weaker than viral promoters. To our knowledge, the presented work validates a biocompatible and effective polymer-facilitated gene-delivery system for both human brain cells and mice for the first time.

Nanogel-mediated delivery of a cocktail of epigenetic drugs plus doxorubicin overcomes drug resistance in breast cancer cells.

Epigenetic modifications (e.g., DNA methylation or histone deacetylation) are commonly implicated in cancer chemoresistance. We previously showed that pretreating resistant MCF-7/ADR breast cancer cells with a demethylating agent (5-aza-2'-deoxycytidine (DAC)) or with an inhibitor of histone deacetylase (suberoylanilide hydroxamic acid (SAHA)) sensitized resistant cells to doxorubicin (DOX) treatment. However, even with increasing doses of DOX, a fraction of resistant cells remained nonresponsive to this pretreatment (~ 25% pretreated with DAC, ~ 45% with SAHA). We hypothesized that pretreating resistant cells with a combination of epigenetic drugs (DAC + SAHA) could more effectively overcome drug resistance. We postulated that delivery of epigenetic drugs encapsulated in biodegradable nanogels (NGs) would further enhance their efficacy. MCF-7/ADR cells were first treated with a single drug vs. a combination of epigenetic drugs, either as solutions or encapsulated in NGs, then subjected to DOX, either in solution or in NGs. Antiproliferative data showed that pretreatment with epigenetic drugs in NGs, then with DOX in NGs, was most effective in overcoming resistance; this treatment inhibited cell growth by > 90%, even at low doses of DOX. Cell cycle analysis showed that a major fraction of cells treated with a cocktail of epigenetic drugs + DOX, all in NG formulations, remained in the G2/M cell cycle arrest phase for a prolonged period. The mechanism of better efficacy of epigenetic drugs in NGs could be attributed to their sustained effect. A similar strategy could be developed for other cancer cells in which drug resistance is due to epigenetic modifications.

Pro-NP™ protect against TiO2 nanoparticle-induced phototoxicity in zebrafish model: exploring potential application for skin care.

Titanium dioxide nanoparticles (TiO2NPs) are used in sunscreen products to protect the skin from the sun's ultraviolet rays. However, following exposure to sunlight, the photocatalytic activity of TiO2NPs can produce an excess of reactive oxygen species (ROS), causing skin cell damage, triggering an inflammatory response. In zebrafish model, we evaluated how well Pro-NP™ (biodegradable NPs containing superoxide dismutase and catalase) could protect them from TiO2NP-induced photo-oxidative stress. We hypothesized that the antioxidant properties of Pro-NP™ would protect zebrafish embryos from the phototoxic effects of TiO2NPs, improving overall survival and growth. Dechorionated embryos were treated with TiO2NPs alone or co-treated with Pro-NP™, and then exposed to simulated sunlight. Pro-NP™ by itself caused no toxicity; however, for embryos exposed to 100 µg/ml TiO2NPs, zebrafish survival was reduced to ∼40% and at 500 µg/ml to ∼10%. In contrast, at 100 µg/ml TiO2NP, co-treatment with Pro-NP™ increased zebrafish survival in a dose-dependent manner. Co-treatment also improved percent of embryos hatching and resulted in normal growth of zebrafish. On the other hand, embryos treated with TiO2NPs alone developed deformities, had reduced pigmentation, and showed severely truncated growth. Pro-NP™ afforded a greater level of protection against TiO2NP-induced phototoxicity than other antioxidants (vitamin E or N-acetylcysteine) commonly used in topical skin care formulations. We conclude that Pro-NP™ exert significant protective effects against TiO2NP-induced phototoxicity and could be developed as a safe, effective skin care product, used alone or in combination with sunscreen products to protect the skin from sun's UV radiation.

Sustained Epigenetic Drug Delivery Depletes Cholesterol-Sphingomyelin Rafts from Resistant Breast Cancer Cells, Influencing Biophysical Characteristics of Membrane Lipids.

Cell-membrane lipid composition can greatly influence biophysical properties of cell membranes, affecting various cellular functions. We previously showed that lipid synthesis becomes altered in the membranes of resistant breast cancer cells (MCF-7/ADR); they form a more rigid, hydrophobic lipid monolayer than do sensitive cell membranes (MCF-7). These changes in membrane lipids of resistant cells, attributed to epigenetic aberration, significantly affected drug transport and endocytic function, thus impacting the efficacy of anticancer drugs. The present study's objective was to determine the effects of the epigenetic drug, 5-aza-2'-deoxycytidine (DAC), delivered in sustained-release nanogels (DAC-NGs), on the composition and biophysical properties of membrane lipids of resistant cells. Resistant and sensitive cells were treated with DAC in solution (DAC-sol) or DAC-NGs, and cell-membrane lipids were isolated and analyzed for lipid composition and biophysical properties. In resistant cells, we found increased formation of cholesterol-sphingomyelin (CHOL-SM) rafts with culturing time, whereas DAC treatment reduced their formation. In general, the effect of DAC-NGs was greater in changing the lipid composition than with DAC-sol. DAC treatment also caused a rise in levels of certain phospholipids and neutral lipids known to increase membrane fluidity, while reducing the levels of certain lipids known to increase membrane rigidity. Isotherm data showed increased lipid membrane fluidity following DAC treatment, attributed to decrease levels of CHOL-SM rafts (lamellar beta [Lß] structures or ordered gel) and a corresponding increase in lipids that form lamellar alpha-structures (Lα, liquid crystalline phase). Sensitive cells showed marginal or insignificant changes in lipid profile following DAC-treatment, suggesting that epigenetic changes affecting lipid biosynthesis are more specific to resistant cells. Since membrane fluidity plays a major role in drug transport and endocytic function, treatment of resistant cells with epigenetic drugs with altered lipid profile could facilitate anticancer drug transport to overcome acquired drug resistance in a combination therapy.

Biophysics of cell membrane lipids in cancer drug resistance: Implications for drug transport and drug delivery with nanoparticles.

In this review, we focus on the biophysics of cell membrane lipids, particularly when cancers develop acquired drug resistance, and how biophysical changes in resistant cell membrane influence drug transport and nanoparticle-mediated drug delivery. Recent advances in membrane lipid research show the varied roles of lipids in regulating membrane P-glycoprotein function, membrane trafficking, apoptotic pathways, drug transport, and endocytic functions, particularly endocytosis, the primary mechanism of cellular uptake of nanoparticle-based drug delivery systems. Since acquired drug resistance alters lipid biosynthesis, understanding the role of lipids in cell membrane biophysics and its effect on drug transport is critical for developing effective therapeutic and drug delivery approaches to overcome drug resistance. Here we discuss novel strategies for (a) modulating the biophysical properties of membrane lipids of resistant cells to facilitate drug transport and regain endocytic function and (b) developing effective nanoparticles based on their biophysical interactions with membrane lipids to enhance drug delivery and overcome drug resistance.

Efficacy of decitabine-loaded nanogels in overcoming cancer drug resistance is mediated via sustained DNA methyltransferase 1 (DNMT1) depletion.

DNA methyltransferase 1 (DNMT1) promotes DNA methylation to maintain cancer drug resistance. The epigenetic drug, decitabine (DAC) is a potent hypomethylating agent, but its effect is transient because of its instability. We tested the efficacy of DAC-loaded nanogels in doxorubicin-resistant breast cancer cells, DAC-resistant melanoma cells, and leukemia cells. DAC in nanogel sustained DNMT1 depletion, prolonged cell arrest in the G2/M cell-cycle phase, and significantly enhanced antiproliferative effect of DAC. The efficacy of DAC-loaded nanogels was more significant in resistant than sensitive cells. Our data suggest that effective delivery of DAC and prolonged DNMT1 depletion are critical to overcoming drug resistance.