Cationic Vitamin E-TPGS Mixed Micelles of Berberine to Neutralize Doxorubicin-Induced Cardiotoxicity via Amelioration of Mitochondrial Dysfunction and Impeding Apoptosis.

Anthracycline antibiotics, namely, doxorubicin (DOX) and daunorubicin, are among the most widely used anticancer therapies, yet are notoriously associated with severe myocardial damage due to oxidative stress and mitochondrial damage. Studies have indicated the strong pharmacological properties of Berberine (Brb) alkaloid, predominantly mediated via mitochondrial functions and nuclear networks. Despite the recent emphasis on Brb in clinical cardioprotective studies, pharmaceutical limitations hamper its clinical use. A nanoformulation for Brb was developed (mMic), incorporating a cationic lipid, oleylamine (OA), into the TPGS-mixed corona of PEGylated-phosphatidylethanolamine (PEG-PE) micelles. Cationic TPGS/PEG-PE mMic with superior Brb loading and stability markedly enhanced both intracellular and mitochondria-tropic Brb activities in cardiovascular muscle cells. Sub-lethal doses of Brb via cationic OA/TPGS mMic, as a DOX co-treatment, resulted in significant mitochondrial apoptosis suppression. In combination with an intense DOX challenge (up to ~50 µM), mitochondria-protective Brb-OA/TPGS mMic showed a significant 24 h recovery of cell viability (p ≤ 0.05-0.01). Mechanistically, the significant relative reduction in apoptotic caspase-9 and elevation of antiapoptotic Bcl-2 seem to mediate the cardioprotective role of Brb-OA/TPGS mMic against DOX. Our report aims to demonstrate the great potential of cationic OA/TPGS-mMic to selectively enhance the protective mitohormetic effect of Brb to mitigate DOX cardiotoxicity.

Need for Expansion of Pharmacy Education Globally for the Growing Field of Nanomedicine.

The emerging landscape of nanomedicine includes a wide variety of active pharmaceutical ingredients and drug formulations. Their design provides nanomedicines with unique features leading to improved pharmacokinetics and pharmacodynamics. They are manufactured using conventional or biotechnological manufacturing processes. Their physical characteristics are vastly different from traditional small-molecule drugs. Pharmacists are important members of the multi-disciplinary team of scientists involved in their development and clinical application. Consequently, their training should lead to an understanding of the complexities associated with the production and evaluation of nanomedicines. Therefore, student pharmacists, post-doctoral researchers, and trainees should be given more exposure to this rapidly evolving class of therapeutics. This commentary will provide an overview of nanomedicine education within the selection of pharmacy programs globally, discuss the current regulatory challenges, and describe different approaches to incorporate nanomedicine science in pharmacy programs around the world.

The Growing Field of Nanomedicine and Its Relevance to Pharmacy Curricula.

The field of nanomedicine is a rapidly growing scientific domain. Nanomedicine encompasses a diverse number of active pharmaceutical ingredients. Submissions of Investigational New Drugs and New Drug Applications have risen dramatically over the last decade. There are over 50 nanomedicines approved for use by the US Food and Drug Administration (FDA). Because of the fundamental role pharmacists will play in therapeutic and administrative decisions regarding nanomedicines, it is imperative for future pharmacists to gain exposure early in their training to this rapidly evolving class of drugs. This commentary describes nanomedicines, discusses current regulatory challenges, and provides recommendations for judicious incorporation of nanomedicine topics into the Doctor of Pharmacy curriculum based on emerging pharmaceutical and clinical science applications.

Efficient Ex Vivo Screening of Agents Targeting Thrombospondin1-Induced Vascular Dysfunction Using a Digital Multiwire Myograph System.

Homeostasis of vascular tone is intricately and delicately maintained systemically and locally, by autonomic nerves and hormones in the blood and by intimal vasoactive substances, respectively. The balance can be acutely or chronically interrupted secondary to many alterations, especially under pathological conditions. Excessive matricellular glycoprotein thrombospondin 1 (TSP1) levels in circulation have been found to play an important role in ischemia-reperfusion injuries of different organs, by acutely suppressing vasorelaxation and chronically remodeling vascular bed. Our laboratory has been interested in identifying new drug moieties, which can selectively and effectively counteract TSP1-induced vascular dysfunction, in order to address associated clinical complications. Preliminary studies using computational docking and molecular models revealed potential drug candidates for further evaluation via vascular functional bioassay to prove the antagonism using an ex vivo vascular model. Herein, we described an efficient screening method for the identification of active drug candidates, by adapting a multiwire myograph system to perform a protocol with different treatments, in the presence of pathological levels of TSP1. We discussed the promising pharmacological evaluation results and suggested suitable modification for versatile applications. We also described the necessity of pre-determination of optimal resting tension to obtain the maximal response, if the experimental test model is different from those with determined optimal resting tension.

Novel Pharmaceutical Strategy for Selective Abrogation of TSP1-Induced Vascular Dysfunction by Decoy Recombinant CD47 Soluble Receptor in Prophylaxis and Treatment Models.

Elevated thrombospondin 1 (TSP1) is a prevalent factor, via cognate receptor CD47, in the pathogenesis of cardiovascular conditions, including ischemia-reperfusion injury (IRI) and pulmonary arterial hypertension (PAH). Moreover, TSP1/CD47 interaction has been found to be associated with platelet hyperaggregability and impaired nitric oxide response, exacerbating progression in IRI and PAH. Pathological TSP1 in circulation arises as a target of our novel therapeutic approach. Our "proof-of-concept" pharmacological strategy relies on recombinant human CD47 peptide (rh-CD47p) as a decoy receptor protein (DRP) to specifically bind TSP1 and neutralize TSP1-impaired vasorelaxation, strongly implicated in IRI and PAH. The binding of rh-CD47p and TSP1 was first verified as the primary mechanism via Western blotting and further quantified with modified ELISA, which also revealed a linear molar dose-dependent interaction. Ex vivo, pretreatment protocol with rh-CD47p (rh-CD47p added prior to TSP1 incubation) demonstrated a prophylactic effect against TSP1-impairment of endothelium-dependent vasodilation. Post-treatment set-up (TSP1 incubation prior to rh-CD47p addition), mimicking pre-existing excessive TSP1 in PAH, reversed TSP1-inhibited vasodilation back to control level. Dose titration identified an effective molar dose range (approx. ≥1:3 of tTSP1:rh-CD47p) for prevention of/recovery from TSP1-induced vascular dysfunction. Our results indicate the great potential for proposed novel decoy rh-CD47p-therapy to abrogate TSP1-associated cardiovascular complications, such as PAH.

Liposomal Delivery of Cyclocreatine Impairs Cancer Cell Bioenergetics Mediating Apoptosis.

Creatine kinase (CK) enzyme overexpression has been suggested to play a role in the process of tumorigenesis and metastasis. Cyclocreatine (CCR) is a substrate analog of creatine kinase (CK), where its phosphorylated form is a poor phosphate donor in comparison with native bioenergetic molecule, creatine phosphate (Cr-P). The compound CCR has been shown to markedly inhibit the growth of a broad spectrum of cancers, both in vitro and in vivo. Intracellularly, CCR is phosphorylated by CK to yield a synthetic phosphagen [(N-phosphorylcyclocreatine (CCR ~P)], with thermodynamic and kinetic properties distinct from those of creatine phosphate (Cr-P). Distinct inhibition of tumor growth and metastasis has been attributed to CCR accumulation as CCR ~P in tumor cells, especially in those expressing a high level of CK protein, with minimal adverse effects. Unfortunately, the clinical use of CCR against malignancies is quite limited due to its amphoteric nature, which accounts for most of its extremely low membrane permeability, as well as limited oral bioavailability (BA) and poor systemic pharmacokinetics (PK).Our current work describes the encapsulation of CCR , utilizing freeze and thaw vesicles (FTV )-composed mostly of saturated PC, DOPE, and Chol-into stealth™ liposomes , postcoated with 4.5 M% PEG-PE. Following physicochemical characterization, in vitro release and cellular uptake kinetics confirmed efficient delivery of liposomal CCR (CCR-Lip), leading to intracellular accumulation of its CC-P metabolic product. Successful delivery of CCR to cancer cell effectively depleted low energetic cancer cells of ATP significantly mediating myc-induced metabolic changes. CCR-Lip showed significant antimetastatic and anticancer effectiveness against both MCF-7 and PC-3 human carcinoma models (p < 0.05-0.01), with 4- to 6-fold lower IC50 values vs. closest drug control. Such shift in bioenergetics was coupled via AMPK and phospho-p53 to the mitochondrial apoptosis effector Bak , thus inducing a cell-intrinsic mechanism to counteract uncontrolled neoplastic proliferation, in target cancer cells. Our novel liposomal delivery system of the CCR substrate analog demonstrated strong inhibition of malignant cell bioenergetics, leading to significant antineoplastic and proapoptotic actions, against different cancers.

Cyclocreatine protects against ischemic injury and enhances cardiac recovery during early reperfusion.

Introduction: A critical mechanism of how hypoxia/ischemia causes irreversible myocardial injury is through the exhaustion of adenosine triphosphate (ATP). Cyclocreatine (CCr) and its water-soluble salt Cyclocreatine-Phosphate (CCrP) are potent bioenergetic agents that preserve high levels of ATP during ischemia. Areas covered: CCr and CCrP treatment prior to the onset of ischemia, preserved high levels of ATP in ischemic myocardium, reduced myocardial cell injury, exerted anti-inflammatory and anti-apoptotic activities, and restored contractile function during reperfusion in animal models of acute myocardial infarction (AMI), global cardiac arrest, cardiopulmonary bypass, and heart transplantation. Medline and Embase (1970 - Feb 2019), the WIPO databank (up to Feb 2019); no language restriction. Expert opinion: This review provides the basis for a number of clinical applications of CCrP and CCr to minimize ischemic injury and necrosis. One strategy is to administer CCrP to AMI patients in the pre-hospital phase, as well as during, or after Percutaneous Coronary Intervention (PCI) procedure to potentially achieve protection of the myocardium, reduce infarcted-size, and, thus, limit the progression to heart failure. Another clinical applications are in predictable myocardial ischemia where pretreatment with CCrP would likely improve outcome and quality of life of patients who will undergo cardiopulmonary bypass for coronary revascularization and end-stage heart failure patients scheduled for heart transplantation.

Anionic and Cationic Vitamin E-TPGS Mixed Polymeric Phospholipid Micellar Vehicles.

Berberine (Brb) is an active isoquinoline alkaloid occurring in various common plant species, with well-known potential for cancer therapy. Earlier reports has shown that Brb not only augments the efficacy of antineoplastic chemotherapy and radiotherapy, but it also exhibits direct anti-mitotic, and pro-apoptotic activities, plus significant anti-angiogenic and anti-metastatic activities in a variety of solid tumors. Notwithstanding its low systemic toxicity, a few pharmaceutical limitations severely hamper the application of Brb in cancer therapy (namely, very slight aqueous solubility and exceedingly low membrane permeability; combined with poor systemic pharmacokinetic, PK, profile).Lipid-based nanocarriers, amphiphilic mixed micelles (Mic) composed of polymeric phospholipid conjugates and PEG-succinate ester of tocopherol were investigated as promising strategy, to improve Brb delivery into tumors. Following physicochemical characterization of micellar Brb, in vitro release studies in simulated physiological media were performed, combined with PK-simulation and in vitro assays of cytotoxicity and direct apoptosis induction in different human prostate cancer cell lines (PC3 and LNPaC).Optimized stealth PEG-PE/TPGS-mixed micelles achieved efficient solubilization of Brb to potentially improve its systemic PK profiles (>30-fold). Our mixed micellar platform resulted in significant enhancement of the pro-apoptotic action and overall anticancer efficacy of Brb, against various in vitro (monolayer and spheroid) models of prostate cancers.

Partially Polymerized Phospholipid Vesicles for Efficient Delivery of Macromolecules.

Lipid-based vesicles, namely cationic liposomal nanocarriers have been recognized early on as one of the most attractive delivery systems for RNA, protein, and oligonucleotides. Despite several advantages of conventional liposomal carriers for therapeutic macromolecules, their flexible and unsupported bilayered membranes can pose some limitations for efficient intracellular delivery of their sensitive cargos. Hence, polymerized liposomes, a concept conceived about 20 years ago, might offer structural solution to current in vivo efficiency concerns affecting traditional cationic phospholipid vectors, especially when adapted to enable superior loading and stability, typically required for effective intracellular delivery of proteins and polynucleotides.Our recent approach attempted to remodel polymerized liposomal vesicles-specifically their semi-rigid membrane structure-to create block-polymerized bilayered vesicles (generally composed of DOTAP: DOPE: Diyne PC in 0.1:1:1 molar ratio). Adopting a modified freeze-dry-rehydration technique allowed modular reassembly of such partially polymerized lipidic vesicles (PPL). Different prototype cationic partially polymerized liposomal preparations (PPLs) were successfully developed (mean particle size range 150-300 nm), demonstrating enhanced physicochemical stability and loading capacity, thus promoting improved intracellular delivery of model RNAi and protein cargos.

CYCLOSPORIN H: A NOVEL ANTI-INFLAMMATORY THERAPY FOR INFLUENZA FLU PATIENTS.

Relatively little is known about the inflammatory mediators and mechanisms that drive the progression of influenza flu infection to cytokine storm, lung dysfunction, organ failure, and ultimately death. Vaccines and antiviral medications cannot control the excessive host inflammatory response associated with severe influenza flu infection. Studies by Elgebaly et al demonstrated the rapid release of a potent inflammatory mediator, recently named Nourin, by local mammalian tissues in response to injury and infection. Nourin is a formyl peptide that acts through the formyl peptide receptor (FPR) on phagocytic leukocytes. As an initial signal in the innate immunity, Nourin stimulates leukocyte chemotaxis, induces acute and chronic inflammation, and stimulates the release of a number of the cytokine storm mediators from monocytes, neutrophils and endothelial cells. Furthermore, Nourin detected in plasma samples from patients with severe influenza infection was much higher compared to moderate influenza. The Nourin antagonist, Cyclosporin H, is a potent anti-inflammatory compound, which acts as a specific competitive antagonist of formyl peptides on the formyl peptide receptor (FPR) on phagocytic: leukocytes. Cyclosporin H completely blocked neutrophil chemotaxis induced by: (a) the standard formyl peptide, f-MLF, (b) the Staphylococcus aureus bacteria-derived formyl peptide Phenol-soluble modulins, such as PSM3a, plus(c) the host-derived Nourin released by: (1) cultured epithelial cells infected with the PR8 HINI influenza virus for 6.to 24 hours, (2),Nourin detected in the serum of mouse model of HINI Swine flu influenza infection for 6 hours , along with (3) Nourin detected in plasma samples collected from severe and moderate influenza pa- tients. Furthermore, in-vivo treatment by Cyclosporin H in the mouse model of HINI Swine flu influenza infection for 5 days markedly reduced lung inflammation and endothelial cell damage. Thus, two clinical applications for Nourin and its antagonist Cyclosporin H are proposed: Diagnostic Application: The blood Nourin test can be used as a key inflammatory biomarker for "early" detection and monitoring of influenza flu patients proceeding to hyperactive inflammation and, thus, permitting early crucial anti-inflammatory therapy. Therapeutic Application: Cyclosporin H will specifically block Nourin as an important initial stimulant of cytokine mediators, and thus can control the development and progression of cytokine storm plus organ inflammation, which usually initiates 3 to 8 days post influenza. Since Cyclosporin H does not target the virus,, it will not develop drug resistance,and will reduce the host uncontrpolled inflammatory response, induced by both new strains of flu viruses and existing viruses with mutations.

Tocotrienol Nanoemulsion Platform of Curcumin Elicit Elevated Apoptosis and Augmentation of Anticancer Efficacy against Breast and Ovarian Carcinomas.

Vitamin E (VE) tocotrienols (T3), recognized for their cancer-specific anti-proliferative and pro-apoptotic activities, have been previously fabricated into bio-active nanoemulsion (NE) formulations. Here, our viscosity-adapted δ-T3 NE platform was developed to additionally incorporate curcumin (CUR), which is known for its potent suppression of signaling pathways involved in malignant cell growth, survival and metastasis. Thanks to efficient 70:30 wt % surfactant mix of Lutrol F-127:VE-TPGS, in conjunction with optimal CUR loading, a prototype CUR in δ-T3 NE was successfully prepared. Model CUR/δ-T3 NE demonstrated excellent nano-scale aspects (mean particle size = 261 nm, PDI = 0.27, and ζ-potential = -35 mV), pharmaceutical stability, and controlled release properties. Suitability for systemic administration was also verified via standardized in vitro biocompatibility and hemocompatibility assays. In two human cancer cells (MCF-7 and OVCAR-8), our CUR/δ-T3 NE prominently suppressed constitutive NF-κB activation, and significantly induced apoptosis. Finally, the combined CUR/δ-T3 NE produced superior cytotoxicity profiles, in concentration- and time-dependent manners (p ≤ 0.05), at least three to four folds lower IC50 than in closest CUR control. The strong synergism, estimated in both cultured carcinomas, revealed the augmented therapeutic efficacy of our CUR/δ-T3 NE combined platform, supporting its strong potential towards pharmaceutical development for cancer therapy.

Development and evaluation of vitamin E d-α-tocopheryl polyethylene glycol 1000 succinate-mixed polymeric phospholipid micelles of berberine as an anticancer nanopharmaceutical.

Berberine (Brb) is an active alkaloid occurring in various common plant species, with well-recognized potential for cancer therapy. Brb not only augments the efficacy of antineoplastic chemotherapy and radiotherapy but also exhibits direct antimitotic and proapoptotic actions, along with distinct antiangiogenic and antimetastatic activities in a variety of tumors. Despite its low systemic toxicity, several pharmaceutical challenges limit the application of Brb in cancer therapy (ie, extremely low solubility and permeability, very poor pharmacokinetics (PKs), and oral bioavailability). Among lipid-based nanocarriers investigated recently for Brb, stealth amphiphilic micelles of polymeric phospholipid conjugates were studied here as a promising strategy to improve Brb delivery to tumors. Specifically, physicochemically stable micelles made of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000] (PEG-PE) mixed with d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) (PEG-succinate ester of vitamin E), in a 3:1 M ratio, increased Brb solubilization by 300%. Our PEG-PE/TPGS-mixed micelles firmly retained the incorporated Brb, displaying extended-release profile in simulated media, with up to 30-fold projected improvement in simulated PKs of Brb. Owing to the markedly better uptake of Brb-containing mixed micelles in vitro, our Brb-mixed micelles nanoformulation significantly amplified apoptosis and overall cytotoxic effectiveness against monolayer and spheroid cultures of human prostate carcinomas (16- to 18-fold lower half-maximal inhibitory concentration values in PC3 and LNPaC, respectively), compared to free Brb. Mixed PEG-PE/TPGS micelles represent a promising delivery platform for the sparingly soluble anticancer agent, Brb, encouraging further pharmaceutical development of this drug for cancer therapy.

Enhanced effectiveness of tocotrienol-based nano-emulsified system for topical delivery against skin carcinomas.

The potent anti-proliferative and pro-apoptotic actions of tocotrienols (T3) against cancer, but not normal tissues, have been hampered by their limited systemic bioavailabilty. Recent expansive development of diverse nanoemulsion (NE) vehicles emphasized their vast potential to improve the effective dosing of different clinical and experimental drugs of lipophilic nature, such as T3. The emphasis of the present work is to develop a pharmaceutically scalable, low-energy nano-emulsification approach for optimized incorporation of T3-rich palm oil (Tocomin®), possessing anticancer activity as a potential cutaneous delivery platform for adjunctive therapy of skin carcinomas, either alone or in combination with other chemotherapeutic agents. Different Tocomin®-NEs, obtained with different homogenization strategies, were screened based on physicochemical uniformity (droplet size, charge and polydispersity) and subjected to stress physical stability testing, along with chemical content analysis (≥90% Tocomin® - incorporation efficiency). Adopted hybrid nano-emulsification of Tocomin®, correlated with highest preservation of DPPH-radical scavenging capacity of active T3 in prototype formulation, Tocomin®-NE, which effectively permeated diffusion cell membranes 4-folds higher than propyleneglycol (PG)-admixed Tocomin® control. Against two different cell models of human cutaneous carcinoma, Tocomin®-hybrid NE demonstrated significantly stronger cytotoxic profiles (p ≤ 0.01), visible in both concentration- and time- dependent manners, with at least 5-folds lower IC50 values, compared to those estimated for the closest Tocomin®-control. The proposed hybrid nano-emulsified formulation of Tocomin® provides simple and stable delivery platform, for effective topical application against keratinocyte tumors.

Development and In Vitro Evaluation of Vitamin E-Enriched Nanoemulsion Vehicles Loaded with Genistein for Chemoprevention Against UVB-Induced Skin Damage.

There is a great need for effective protection against cutaneous pathologies arising from chronic exposure to harmful solar UVB radiations. A promising pharmaceutical strategy to improve the efficacy of chemotherapeutic/preventative natural compounds (e.g., soy isoflavone Genistein, Gen) is to enhance their dermal delivery using nanoemulsion (NE) formulations. This report investigates the development of nanoemulsified tocotrienol(T3)-rich fraction of red palm oil (Tocomin®), to yield an optimal NE delivery system for dermal photoprotection (z-average size <150 nm, ζ-potential ≈ -30 mV, polydispersity index < 0.25). Physicochemical characterization and photostability studies indicate NE formulations utilizing surfactant mixture (Smix) of Solutol® HS-15 (SHS15) blended with vitamin E TPGS (TPGS) as cosurfactant was significantly superior to formulations that utilized Lutrol® F68 (LF68) as the cosurfactant. A ratio of 60:40 of SHS15-TPGS-NE was further identified as lead Tocomin® NE topical platform using in vitro pharmaceutical skin reactivity studies that assess cutaneous irritancy and cytotoxicity. Prototype Tocomin® NE loaded with the antiphotocarcinogenic molecule Gen (Gen-Tocomin® NE) showed slow-release profile in both liquid and cream forms. Gen-Tocomin® NE also showed excellent biocompatibility, and provided substantial UVB protection to cultured subcutaneous L929 fibroblasts, indicating the great potential of our Tocomin® NE warranting further prototype development as topical pharmaceutical platform for skin photoprotection applications.

Layered nanoemulsions as mucoadhesive buccal systems for controlled delivery of oral cancer therapeutics.

Oral cavity and oropharyngeal cancers are considered the eighth most common cancer worldwide, with relatively poor prognosis (62% of patients surviving 5 years, after diagnosis). The aim of this study was to develop a proof-of-concept mucoadhesive lozenge/buccal tablet, as a potential platform for direct sustained delivery of therapeutic antimitotic nanomedicines. Our system would serve as an adjuvant therapy for oral cancer patients undergoing full-scale diagnostic and operative treatment plans. We utilized lipid-based nanocarriers, namely nanoemulsions (NEs), containing mixed-polyethoxylated emulsifiers and a tocopheryl moiety-enriched oil phase. Prototype NEs, loaded with the proapoptotic lipophilic drug genistein (Gen), were further processed into buccal tablet formulations. The chitosan polyelectrolyte solution overcoat rendered NE droplets cationic, by acting as a mucoadhesive interfacial NE layer. With approximate size of 110 nm, the positively charged chitosan-layered NE (+25 mV) vs negatively charged chitosan-free/primary aqueous NE (-28 mV) exhibited a controlled-release profile and effective mucoadhesion for liquid oral spray prototypes. When punch-pressed, porous NE-based buccal tablets were physically evaluated for hardness, friability, and swelling in addition to ex vivo tissue mucoadhesion force and retention time measurements. Chitosan-containing NE tablets were found equivalent to primary NE and placebo tablets in compression tests, yet significantly superior in all ex vivo adhesion and in vitro release assays (P≤0.05). Following biocompatibility screening of prototype chitosan-layered NEs, substantial anticancer activity of selected cationic Gen-loaded NE formulations, against two oropahryngeal carcinomas, was observed. The data strongly indicate the potential of such nanomucoadhesive systems as maintenance therapy for oral cancer patients awaiting surgical removal, or postresection of identified cancerous lesions.

Mitochondriotropic nanoemulsified genistein-loaded vehicles for cancer therapy.

Genistein (Gen), a major soy isoflavone, produces extensive pro-apoptotic anticancer effects, mediated predominantly via induction of mitochondrial damage. Based on several biophysical model criteria, our rational assumptions for the native mitochondrial selectivity of Gen allowed its design as a cationic lipid-based nanocarrier (NC) system. Proof-of-concept nano-formulations, lipidic micelles (Mic), and nanoemulsions (NEs) incorporated Gen, which serves as therapeutic and targeting moieties, specific for mitochondria. Our in vitro experimental data demonstrated superior physicochemical properties and significant cytotoxicity of Gen-NCs (five- to tenfolds lower EC50) compared to all drug controls, in hepatic and colon carcinomas. The established mitochondria-specific accumulation of the various Gen-NCs positively correlated with marked mitochondrial depolarization effects. Within first 24 h, Gen-NC treatments ultimately lead to distinct activation of intrinsic apoptotic pathway markers, such as cytosolic cytochrome c and specific caspase-9 vs. nonspecific caspases-3, 7, and 8. Such mechanistic evidence of the mitochondriotropic activity of our Gen-NC platforms favors their prospective as intracellularly targeted delivery nano-vehicles, to enhance anticancer efficacy of different co-formulated chemotherapeutic agents.

Enhanced cytotoxicity of optimized liposomal genistein via specific induction of apoptosis in breast, ovarian and prostate carcinomas.

Clinical use of genistein against cancer is limited by its extremely low aqueous solubility, poor bioavailability and pharmacokinetics. Based on structural analogy with steroidal compounds, liposomal vehicle compositions were designed and optimized for maximum incorporation of genistein's flavonoid structure. Model conventional and stealth liposomes of genistein (GenLip)--incorporating unsaturated phospholipids and cholesterol--have demonstrated enhanced drug solubilization (over 350-folds > aqueous drug solution), shelf-life stability, and extended release profile. Owing to effective cellular delivery, preservation of genistein's antioxidant activity was confirmed through marked neutralization of peroxides via GenLip, in both quantitative and microscopic fluorescent-probe oxidation assays. Furthermore, significant broad-spectrum anticancer efficacy of GenLip, in murine and human cancer cell lines (p < 0.05-0.001), was achieved in a concentration and time-dependent manner--approx. 5-7 lower IC50 values versus all non-incorporated drug controls. Indicative of key pro-apoptotic activity, GenLip produced DNA laddering, with 1/3 of free drug solution content, and resulted in the highest induction level of P53-independent apoptotic pathway markers, compared to all treatments, in our assays (namely, mitochondrial polarization, and caspase-3/7 enzymes). Our proof-of-principle pharmaceutical design of genistein-loaded liposomes shows optimal loading capacity and physico-chemical properties, which improved cellular delivery and specific pro-apototic effectiveness of incorporated drug, against various cancers.

Mitochondria-specific pro-apoptotic activity of genistein lipidic nanocarriers.

Genistein (Gen) soy isoflavone produces extensive pro-apoptotic anticancer effects, mediated predominantly via induction of mitochondrial damages. Rationalization of the native mitochondrial selectivity of Gen, utilizing biophysical model assumptions, led to our design of cationic lipid-based nanocarriers (NC) of Gen. Prototype nanoformulations, lipidic micelles (Mic) and nanoemulsions (NEs) incorporated Gen to serve as both therapeutic and targeting moieties, specific for mitochondria. Both Gen-NCs, showing superior physicochemical properties, produced significant cytotoxicity (5-10-fold lower EC50), compared to all drug controls, in hepatic and colon carcinomas. Owing to the mitochondria-specific accumulation of Gen-NCs, their mitochondrial depolarization effect was most evident, leading to marked activation of intrinsic apoptotic pathway markers--cytosolic cytochrme c and specific caspase-9--thus, confirming the direct mitochondrial action of Gen-NCs. This mechanistic evidence of the mitochondria specificity of our Gen-NE and Gen-Mic strongly indicates their potential as targeted delivery nanosystems to augment anticancer efficacy of many lipophilic chemotherapeutics.