The Progress and Evolving Trends in Nucleic-Acid-Based Therapies

Nucleic-acid-based therapies have emerged as a pivotal domain within contemporary biomedical science, marked by significant advancements in recent years. These innovative treatments primarily operate through the precise binding of DNA or RNA molecules to discrete target genes, subsequently suppressing the expression of the target proteins. The spectrum of nucleic-acid-based therapies encompasses antisense oligonucleotides (ASOs), small interfering RNAs (siRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs), etc. Compared to more traditional medicinal approaches, nucleic-acid-based therapies stand out for their highly targeted action on specific genes, as well as their potential for chemical modification to improve resistance to nucleases, ensuring sustained therapeutic activity and mitigating immunogenicity concerns. Nevertheless, these molecules' limited cellular permeability necessitates the deployment of delivery vectors to enhance their intracellular uptake and stability. As nucleic-acid-based therapies progressively display promising pharmacodynamic profiles, there has been a burgeoning interest in these treatments for applications in clinical research. This review aims to summarize the variety of nucleic acid drugs and their mechanisms, evaluate the present status in research and application, discourse on prospective trends, and potential challenges ahead. These innovative therapeutics are anticipated to assume a pivotal role in the management of a wide array of diseases.

Development of posaconazole nanocrystalline solid dispersion: preparation, characterization and in vivo evaluation

OBJECTIVE

Posaconazole (PCZ) is an antifungal drug, which acts by inhibiting the lanosterol-14α-demethylase enzyme. It is a biopharmaceutical classification system class II drug with its bioavailability being limited by poor aqueous solubility. The aim of this study was to improve the oral bioavailability of PCZ by preparing nanocrystalline solid dispersion (NCS).

METHODS

PCZ-NCS was prepared by a combination of precipitation and high-pressure homogenization followed by freeze-drying. Several different surfactants and polymers were screened to produce NCS with smaller particle size and higher stability.

RESULTS

The optimized NCS formulation containing 0.2% Eudragit S100 and 0.2% SLS was found to provide the average particle size of 73.31 ± 4.7 nm with a polydispersity index of 0.23 ± 0.03. Scanning electron microscopy revealed the preparation of homogeneous and rounded particles. Differential scanning calorimetry and X-ray diffraction confirmed crystalline nature of NCS. Nanonization increased the saturation solubility of PCZ by about 18-fold in comparison with the neat drug. Intrinsic dissolution study showed 93% dissolution of PCZ within the first 10 min. In vivo pharmacokinetic study in Wistar rats showed that Cmax and AUCtotal of PCZ-NCS increased by 2.58- and 2.64-fold compared to the marketed formulation.

CONCLUSION

PCZ-NCS formulation presents a viable approach for enhancing the oral bioavailability of PCZ.

Recent Trends in Nanocarrier-Based Drug Delivery System for Prostate Cancer

Prostate cancer remains a significant global health concern, requiring innovative approaches for improved therapeutic outcomes. In recent years, nanoparticle-based drug delivery systems have emerged as promising strategies to address the limitations of conventional cancer chemotherapy. The key trends include utilizing nanoparticles for enhancing drug delivery to prostate cancer cells. Nanoparticles have some advantages such as improved drug solubility, prolonged circulation time, and targeted delivery of drugs. Encapsulation of chemotherapeutic agents within nanoparticles allows for controlled release kinetics, reducing systemic toxicity while maintaining therapeutic efficacy. Additionally, site-specific accumulation within the prostate tumor microenvironment is made possible by the functionalization of nanocarrier with targeted ligands, improving therapeutic effectiveness. This article highlights the basics of prostate cancer, statistics of prostate cancer, mechanism of multidrug resistance, targeting approach, and different types of nanocarrier used for the treatment of prostate cancer. It also includes the applications of nanocarriers for the treatment of prostate cancer and clinical trial studies to validate the safety and efficacy of the innovative drug delivery systems. The article focused on developing nanocarrier-based drug delivery systems, with the goal of translating these advancements into clinical applications in the future.

Surface Functionalized Lipid Nanoparticles in Promoting Therapeutic Outcomes: An Insight View of the Dynamic Drug Delivery System

Compared to the conventional approach, nanoparticles (NPs) facilitate a non-hazardous, non-toxic, non-interactive, and biocompatible system, rendering them incredibly promising for improving drug delivery to target cells. When that comes to accomplishing specific therapeutic agents like drugs, peptides, nucleotides, etc., lipidic nanoparticulate systems have emerged as even more robust. They have asserted impressive ability in bypassing physiological and cellular barriers, evading lysosomal capture and the proton sponge effect, optimizing bioavailability, and compliance, lowering doses, and boosting therapeutic efficacy. However, the lack of selectivity at the cellular level hinders its ability to accomplish its potential to the fullest. The inclusion of surface functionalization to the lipidic NPs might certainly assist them in adapting to the basic biological demands of a specific pathological condition. Several ligands, including peptides, enzymes, polymers, saccharides, antibodies, etc., can be functionalized onto the surface of lipidic NPs to achieve cellular selectivity and avoid bioactivity challenges. This review provides a comprehensive outline for functionalizing lipid-based NPs systems in prominence over target selectivity. Emphasis has been put upon the strategies for reinforcing the therapeutic performance of lipidic nano carriers' using a variety of ligands alongside instances of relevant commercial formulations.

The Use of Lipid-based Nanocarriers to Improve Ovarian Cancer Treatment: An Overview of Recent Developments

Ovarian cancer poses a formidable health challenge for women globally, necessitating innovative therapeutic approaches. This review provides a succinct summary of the current research status on lipid-based nanocarriers in the context of ovarian cancer treatment. Lipid-based nanocarriers, including liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs), offer a promising solution for delivering anticancer drugs with enhanced therapeutic effectiveness and reduced adverse effects. Their versatility in transporting both hydrophobic and hydrophilic medications makes them well-suited for a diverse range of anticancer drugs. Active targeting techniques like ligand-conjugation and surface modifications have been used to reduce off-target effects and achieve tumour-specific medication delivery. The study explores formulation techniques and adjustments meant to enhance drug stability and encapsulation in these nanocarriers. Encouraging results from clinical trials and preclinical investigations underscore the promise of lipid-based nanocarriers in ovarian cancer treatment, providing optimism for improved patient outcomes. Notwithstanding these advancements, challenges related to clearance, long-term stability, and scalable manufacturing persist. Successfully translating lipidbased nanocarriers into clinical practice requires addressing these hurdles. To sum up, lipidbased nanocarriers are a viable strategy to improve the effectiveness of therapy for ovarian cancer. With their more focused medication administration and lower systemic toxicity, they may completely change the way ovarian cancer is treated and increase patient survival rates. Lipidbased nanocarriers need to be further researched and developed to become a therapeutically viable treatment for ovarian cancer.

Precision Therapy of Recurrent Breast Cancer through Targeting Different Malignant Tumor Cells with a HER2/CD44-Targeted Hydrogel Nanobot

Heterogeneity and drug resistance of tumor cells are the leading causes of incurability and poor survival for patients with recurrent breast cancer. In order to accurately deliver the biological anticancer drugs to different subtypes of malignant tumor cells for omnidirectional targeted treatment of recurrent breast cancer, a distinct design is demonstrated by embedding liposome-based nanocomplexes containing pro-apoptotic peptide and survivin siRNA drugs (LPR) into Herceptin/hyaluronic acid cross-linked nanohydrogels (Herceptin-HA) to fabricate a HER2/CD44-targeted hydrogel nanobot (named as ALPR). ALPR delivered cargoes to the cells overexpressing CD44 and HER2, followed by Herceptin-HA biodegradation, subsequently, the exposed lipid component containing DOPE fused with the endosomal membrane and released peptide and siRNA into the cytoplasm. These experiments indicated that ALPR can specifically deliver Herceptin, peptide, and siRNA drugs to HER2-positive SKBR-3, triple-negative MDA-MB-231, and HER2-negative drug-resistant MCF-7 human breast cancer cells. ALPR completely inhibited the growth of heterogeneous breast tumors via multichannel synergistic effects: disrupting mitochondria, downregulating the survivin gene, and blocking HER2 receptors on the surface of HER2-positive cells. The present design overcomes the chemical drug resistance and opens a feasible route for the combinative treatment of recurrent breast cancer, even other solid tumors, utilizing different kinds of biological drugs.

Effect of Different Seed Crystals on the Supersaturation State of Ritonavir Tablets Prepared by Hot-Melt Extrusion

Hot-melt extrusion (HME) is a technology increasingly common for the commercial production of pharmaceutical amorphous solid dispersions (ASDs), especially for poorly water-soluble active pharmaceutical ingredients (APIs). However, recrystallization of the APIs during dissolution must be prevented to maintain the supersaturation state enabled by ASD. Unfortunately, the amorphous formulation may be contaminated by seed crystals during the HME manufacturing process, which could lead to undesirable crystal growth during the dissolution process. In this study, the dissolution behavior of ritonavir ASD tablets prepared using both Form I and Form II polymorphs was examined, and the effects of different seed crystals on crystal growth rates were investigated. The aim was to understand how the presence of seed crystals can impact the dissolution of ritonavir, and to determine the optimal polymorph and seeding conditions for the production of ASDs. The results showed that both Form I and Form II ritonavir tablets had similar dissolution profiles, which were also similar to the reference listed drug (RLD). However, it was observed that the presence of seed crystals, particularly the metastable Form I seed, led to more precipitation compared to the stable Form II seed in all formulations. The Form I crystals that precipitated from the supersaturated solution were easily dispersed in the solution and could serve as seeds to facilitate crystal growth. On the other hand, Form II crystals tended to grow more slowly and presented as aggregates. The addition of both Form I and Form II seeds could affect their precipitation behaviors, and the amount and form of the seeds had significant effects on the precipitation process of the RLD tablets, as are the tablets prepared with different polymorphs. In conclusion, the study highlights the importance of minimizing the contamination risk of seed crystals during the manufacturing process and selecting the appropriate polymorph for the production of ASDs.

Nanoligomers Targeting Human miRNA for the Treatment of Severe COVID-19 Are Safe and Nontoxic in Mice

The devastating effects of the coronavirus disease 2019 (COVID-19) pandemic have made clear a global necessity for antiviral strategies. Most fatalities associated with infection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) result at least partially from uncontrolled host immune response. Here, we use an antisense compound targeting a previously identified microRNA (miRNA) linked to severe cases of COVID-19. The compound binds specifically to the miRNA in question, miR-2392, which is produced by human cells in several disease states. The safety and biodistribution of this compound were tested in a mouse model via intranasal, intraperitoneal, and intravenous administration. The compound did not cause any toxic responses in mice based on measured parameters, including body weight, serum biomarkers for inflammation, and organ histopathology. No immunogenicity from the compound was observed with any administration route. Intranasal administration resulted in excellent and rapid biodistribution to the lungs, the main site of infection for SARS-CoV-2. Pharmacokinetic and biodistribution studies reveal delivery to different organs, including lungs, liver, kidneys, and spleen. The compound was largely cleared through the kidneys and excreted via the urine, with no accumulation observed in first-pass organs. The compound is concluded to be a safe potential antiviral treatment for COVID-19.

Studies on the Vitrified and Cryomilled Bosentan

In this paper, several experimental techniques [X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetry, Fourier transform infrared spectroscopy, and broad-band dielectric spectroscopy] have been applied to characterize the structural and thermal properties, H-bonding pattern, and molecular dynamics of amorphous bosentan (BOS) obtained by vitrification and cryomilling of the monohydrate crystalline form of this drug. Samples prepared by these two methods were found to be similar with regard to their internal structure, H-bonding scheme, and structural (α) dynamics in the supercooled liquid state. However, based on the analysis of α-relaxation times (dielectric measurements) predicted for temperatures below the glass-transition temperature (T_g), as well as DSC thermograms, it was concluded that the cryoground sample is more aged (and probably more physically stable) compared to the vitrified one. Interestingly, such differences in physical properties turned out to be reflected in the lower intrinsic dissolution rate of BOS obtained by cryomilling (in the first 15 min of dissolution test) in comparison to the vitrified drug. Furthermore, we showed that cryogrinding of the crystalline BOS monohydrate leads to the formation of a nearly anhydrous amorphous sample. This finding, different from that reported by Megarry et al. [Carbohydr. Res.2011, 346, 1061−106421492830] for trehalose (TRE), was revealed on the basis of infrared and thermal measurements. Finally, two various hypotheses explaining water removal upon cryomilling have been discussed in the manuscript.

Transforming Tea Catechins into Potent Anticancer Compound: Analysis of Three Boronated-PEG Delivery System

Chemotherapy has led to many undesirable side effects, as these are toxic drugs that are unable to differentiate between cancer and normal cells. Polyphenols (tea catechins) are an ideal option as alternative chemotherapeutics owing to their inherent anticancer properties, antioxidant properties and being naturally occurring compounds, are deemed safe for consumption. However, without proper administration, the bioavailability of these compounds is low and inefficient. Therefore, proper delivery of these phenolic compounds is vital for cancer therapy. Herein, we analyzed three potential solutions to creating nanoparticle drugs using naturally occurring phenolic compounds (piceatannol (PIC), epigallocatechin gallate hydrophilic (EGCG) and l-epicatechin (EPI)). By using a simple pi-pi stacking mechanism, we utilized boronated PEG (PEG-Br) as an anchor to efficiently load EPI, PIC and EGCG, respectively, to produce three effective phenolic compound-based nanoparticles, which could be delivered safely in systemic circulation, yet detach from its cargo intracellularly to exert its anticancer effect for effective cancer therapy.

An exploratory first-in-man study to investigate the pharmacokinetics and safety of liposomal dexamethasone at a 2- and 1-week interval in patients with metastatic castration resistant prostate cancer

Dexamethasone has antitumor activity in metastatic castration resistant prostate cancer (mCRPC). We aimed to investigate intravenous liposome-encapsulated dexamethasone disodium phosphate (liposomal dexamethasone) administration in mCRPC patients. In this exploratory first-in-man study, patients in part A received a starting dose of 10 mg followed by five doses of 20 mg liposomal dexamethasone at 2-week intervals. Upon review of part A safety, patients in part B received 10 weekly doses of 18.5 mg. Primary outcomes were safety and pharmacokinetic profile, secondary outcome was antitumor efficacy. Nine mCRPC patients (5 part A, 4 part B) were enrolled. All patients experienced grade 1-2 toxicity, one (part B) patient experienced grade 3 toxicity (permanent bladder catheter-related urosepsis). No infusion-related adverse events occurred. One patient had upsloping glucose levels ≤9.1 mmol/L. Trough plasma concentrations of liposomal- and free dexamethasone were below the lower limit of quantification (LLOQ) in part A, and above LLOQ in three patients in part B (t1/2 ~50 h for liposomal dexamethasone), trough concentrations of liposomal- and free dexamethasone increased toward the end of the study. In seven of nine patients (78%) patients, stable disease was observed in bone and/or CT scans at follow-up, and in one (part B) of these seven patients a >50% PSA biochemical response was observed. Bi- and once weekly administrations of IV liposomal dexamethasone were well-tolerated. Weekly dosing enabled trough concentrations of liposomal- and free dexamethasone >LLOQ. The data presented support further clinical investigation in well-powered studies. Clinical trial registration: ISRCTN 10011715.

Conformation-sensitive targeting of lipid nanoparticles for RNA therapeutics

The successful in vivo implementation of gene expression modulation strategies relies on effective, non-immunogenic delivery vehicles. Lipid nanoparticles are one of the most advanced non-viral clinically approved nucleic-acid delivery systems. Yet lipid nanoparticles accumulate naturally in liver cells upon intravenous administration, and hence, there is an urgent need to enhance uptake by other cell types. Here we use a conformation-sensitive targeting strategy to achieve in vivo gene silencing in a selective subset of leukocytes and show potential therapeutic applications in a murine model of colitis. In particular, by targeting the high-affinity conformation of α₄β₇ integrin, which is a hallmark of inflammatory gut-homing leukocytes, we silenced interferon-γ in the gut, resulting in an improved therapeutic outcome in experimental colitis. The lipid nanoparticles did not induce adverse immune activation or liver toxicity. These results suggest that our lipid nanoparticle targeting strategy might be applied for selective delivery of payloads to other conformation-sensitive targets.

microRNAs involved in psoriasis and cardiovascular diseases

Psoriasis is a chronic inflammatory disease involving the skin. Both genetic and environmental factors play a pathogenic role in psoriasis and contribute to the severity of the disease. Psoriasis, in fact, has been associated with different comorbidities such as diabetes, metabolic syndrome, gastrointestinal or kidney diseases, cardiovascular disease (CVD), and cerebrovascular diseases (CeVD). Indeed, life expectancy in severe psoriasis is reduced by up to 5 years due to CVD and CeVD. Moreover, patients with severe psoriasis have a higher prevalence of traditional cardiovascular (CV) risk factors, including dyslipidemia, diabetes, smoking, and hypertension. Further, systemic inflammation is associated with oxidative stress increase and induces endothelial damage and atherosclerosis progression. Different miRNA have been already described in psoriasis, both in the skin tissues and in the blood flow, to play a role in the progression of disease. In this review, we will summarize and discuss the most important miRNAs that play a role in psoriasis and are also linked to CVD.

Computational and Experimental Approaches to Investigate Lipid Nanoparticles as Drug and Gene Delivery Systems

Lipid nanoparticles (LNPs) have been widely applied in drug and gene delivery. More than twenty years ago, DoxilTM was the first LNPs-based drug approved by the US Food and Drug Administration (FDA). Since then, with decades of research and development, more and more LNP-based therapeutics have been used to treat diverse diseases, which often offer the benefits of reduced toxicity and/or enhanced efficacy compared to the active ingredients alone. Here, we provide a review of recent advances in the development of efficient and robust LNPs for drug/gene delivery. We emphasize the importance of rationally combining experimental and computational approaches, especially those providing multiscale structural and functional information of LNPs, to the design of novel and powerful LNP-based delivery systems.

Safe Nanoparticles: Are We There Yet?

The field of nanotechnology has grown over the last two decades and made the transition from the benchtop to applied technologies. Nanoscale-sized particles, or nanoparticles, have emerged as promising tools with broad applications in drug delivery, diagnostics, cosmetics and several other biological and non-biological areas. These advances lead to questions about nanoparticle safety. Despite considerable efforts to understand the toxicity and safety of these nanoparticles, many of these questions are not yet fully answered. Nevertheless, these efforts have identified several approaches to minimize and prevent nanoparticle toxicity to promote safer nanotechnology. This review summarizes our current knowledge on nanoparticles, their toxic effects, their interactions with mammalian cells and finally current approaches to minimizing their toxicity.

The New Frontiers in Neurodegenerative Diseases Treatment: Liposomal-Based Strategies

In the last decade, the onset of neurodegenerative (ND) diseases is strongly widespread due to the age increase of the world population. Despite the intensive investigations boosted by the scientific community, an efficacious therapy has not been outlined yet. The drugs commonly used are only able to relieve symptom severity; following their oral or intravenous administration routes, their effectiveness is strictly limited due to their low ability to reach the Central Nervous System (CNS) overcoming the Blood Brain Barrier (BBB). Starting from these assumptions, the engineered-nanocarriers, such as lipid-nanocarriers, are suitable agents to enhance the delivery of drugs into the CNS due to their high solubility, bioavailability, and stability. Liposomal delivery systems are considered to be the ideal carriers, not only for conventional drugs but also for neuroprotective small molecules and green-extracted compounds. In the current work, the LP-based drug delivery improvements in in vivo applications against ND disorders were carefully assessed.

Comprehensive Survey on Nanobiomaterials for Bone Tissue Engineering Applications

One of the most important ideas ever produced by the application of materials science to the medical field is the notion of biomaterials. The nanostructured biomaterials play a crucial role in the development of new treatment strategies including not only the replacement of tissues and organs, but also repair and regeneration. They are designed to interact with damaged or injured tissues to induce regeneration, or as a forest for the production of laboratory tissues, so they must be micro-environmentally sensitive. The existing materials have many limitations, including impaired cell attachment, proliferation, and toxicity. Nanotechnology may open new avenues to bone tissue engineering by forming new assemblies similar in size and shape to the existing hierarchical bone structure. Organic and inorganic nanobiomaterials are increasingly used for bone tissue engineering applications because they may allow to overcome some of the current restrictions entailed by bone regeneration methods. This review covers the applications of different organic and inorganic nanobiomaterials in the field of hard tissue engineering.

Switching from Conventional to Nano-natural Phytochemicals to Prevent and Treat Cancers: Special Emphasis on Resveratrol

BACKGROUND

Natural phytochemicals and their derivatives have been used in medicine since prehistoric times. Natural phytochemicals have potential uses against various disorders, including cancers. However, due to low bioavailability, their success in clinical trials has not been reproduced. Nanotechnology has played a vital role in providing new directions for diagnosis, prevention, and treatment of different disorders, and of cancer in particular. Nanotechnology has demonstrated the capability to deliver conventional natural products with poor solubility or a short half-life to target specific sites in the body and regulate the release of drugs. Among the natural products, the phytoalexin resveratrol has demonstrated therapeutic effects, including antioxidant, antiinflammatory, and anti-proliferative effects, as well as the potential to inhibit the initiation and promotion of cancer. However, low water solubility and extensive first-pass metabolism lead to poor bioavailability of resveratrol, hindering its potential. Conventional dosage forms of resveratrol, such as tablets, capsules, dry powder, and injections, have met with limited success. Nanoformulations are now being investigated to improve the pharmacokinetic characteristics, as well as to enhance the bioavailability and targetability of resveratrol.

OBJECTIVES

This review details the therapeutic effectiveness, mode of action, and pharmacokinetic limitations of resveratrol, as well as discusses the successes and challenges of resveratrol nanoformulations. Modern nanotechnology techniques to enhance the encapsulation of resveratrol within nanoparticles and thereby enhance its therapeutic effects are emphasized.

CONCLUSION

To date, no resveratrol-based nanosystems are in clinical use, and this review would provide a new direction for further investigations on innovative nanodevices that could consolidate the anticancer potential of resveratrol.

Lactoferrin in Bone Tissue Regeneration

Among the multiple properties exhibited by lactoferrin (Lf), its involvement in bone regeneration processes is of great interest at the present time. A series of in vitro and in vivo studies have revealed the ability of Lf to promote survival, proliferation and differentiation of osteoblast cells and to inhibit bone resorption mediated by osteoclasts. Although the mechanism underlying the action of Lf in bone cells is still not fully elucidated, it has been shown that its mode of action leading to the survival of osteoblasts is complemented by its mitogenic effect. Activation of several signalling pathways and gene expression, in an LRPdependent or independent manner, has been identified. Unlike the effects on osteoblasts, the action on osteoclasts is different, with Lf leading to a total arrest of osteoclastogenesis. Due to the positive effect of Lf on osteoblasts, the potential use of Lf alone or in combination with different biologically active compounds in bone tissue regeneration and the treatment of bone diseases is of great interest. Since the bioavailability of Lf in vivo is poor, a nanotechnology- based strategy to improve the biological properties of Lf was developed. The investigated formulations include incorporation of Lf into collagen membranes, gelatin hydrogel, liposomes, loading onto nanofibers, porous microspheres, or coating onto silica/titan based implants. Lf has also been coupled with other biologically active compounds such as biomimetic hydroxyapatite, in order to improve the efficacy of biomaterials used in the regulation of bone homeostasis. This review aims to provide an up-to-date review of research on the involvement of Lf in bone growth and healing and on its use as a potential therapeutic factor in bone tissue regeneration.

Recent advances in siRNA delivery mediated by lipid-based nanoparticles

Small interfering RNA (siRNA) has been expected to be a unique pharmaceutic for the treatment of broad-spectrum intractable diseases. However, its unfavorable properties such as easy degradation in the blood and negative-charge density are still a formidable barrier for clinical use. For disruption of this barrier, siRNA delivery technology has been significantly advanced in the past two decades. The approval of Patisiran (ONPATTRO™) for the treatment of transthyretin-mediated amyloidosis, the first approved siRNA drug, is a most important milestone. Since lipid-based nanoparticles (LNPs) are used in Patisiran, LNP-based siRNA delivery is now of significant interest for the development of the next siRNA formulation. In this review, we describe the design of LNPs for the improvement of siRNA properties, bioavailability, and pharmacokinetics. Recently, a number of siRNA-encapsulated LNPs were reported for the treatment of intractable diseases such as cancer, viral infection, inflammatory neurological disorder, and genetic diseases. We believe that these contributions address and will promote the development of an effective LNP-based siRNA delivery system and siRNA formulation.

Role of Ceramides in Drug Delivery

Ceramides belong to the sphingolipid group of lipids, which serve as both intracellular and intercellular messengers and as regulatory molecules that play essential roles in signal transduction, inflammation, angiogenesis, and metabolic disorders such as diabetes, neurodegenerative diseases, and cancer cell degeneration. Ceramides also play an important structural role in cell membranes by increasing their rigidity, creating micro-domains (rafts and caveolae), and altering membrane permeability; all these events are involved in the cell signaling. Ceramides constitute approximately half of the lipid composition in the human skin contributing to barrier function as well as epidermal signaling as they affect both proliferation and apoptosis of keratinocytes. Incorporation of ceramides in topical preparations as functional lipids appears to alter skin barrier functions. Ceramides also appear to enhance the bioavailability of drugs by acting as lipid delivery systems. They appear to regulate the ocular inflammation signaling, and external ceramides have shown relief in the anterior and posterior eye disorders. Ceramides play a structural role in liposome formulations and enhance the cellular uptake of amphiphilic drugs, such as chemotherapies. This review presents an overview of the various biological functions of ceramides, and their utility in topical, oral, ocular, and chemotherapeutic drug delivery.

Application of Nanotechnology in Targeting of Cancer Stem Cells: A Review

Cancer is increasingly apparent as a systems-level, network happening. The central tendency of malignant alteration can be described as a two-phase procedure, where an initial increase of network plasticity is followed by reducing plasticity at late stages of tumor improvement. Cancer stem cells (CSCs) are cancer cells that take characteristics associated with normal stem cells. Cancer therapy has been based on the concept that most of the cancer cells have a similar ability to separate metastasise and kill the host. In this review, we addressed the use of nanotechnology in the treatment of cancer stem cells.

Medical and dental applications of nanomedicines

Nanoparticles are tiny materials with nanosized components less than 100 nm in at least one dimension with physicochemical properties, which make them very attractive for medical application. These compounds have been evaluated as potential medicines for several decades. Nanotechnology has provided advances in the various fields of health sciences such as diagnosis, prevention and treatment by application of the agents named nanomedicines, including proteins, polymers, micelles, dendrimers, liposomes, emulsions, nanocapsules and nanoparticles. These materials can act as a scaffold, gene/drug delivery, tumor suppressor, conjugated with surgical implant, etc. They can also use as a nanocomposite, artificial tooth and dental caries preventing agent in the dentistry science. This current review tries to summarize recent applications of nanomedicine in the medical and dental fields.

Overcoming chemo/radio-resistance of pancreatic cancer by inhibiting STAT3 signaling

Chemo/radio-therapy resistance to the deadly pancreatic cancer is mainly due to the failure to kill pancreatic cancer stem cells (CSCs). Signal transducer and activator of transcription 3 (STAT3) is activated in pancreatic CSCs and, therefore, may be a valid target for overcoming therapeutic resistance. Here we investigated the potential of STAT3 inhibition in sensitizing pancreatic cancer to chemo/radio-therapy. We found that the levels of nuclear pSTAT3 in pancreatic cancer correlated with advanced tumor grade and poor patient outcome. Liposomal delivery of a STAT3 inhibitor FLLL32 (Lip-FLLL32) inhibited STAT3 phosphorylation and STAT3 target genes in pancreatic cancer cells and tumors. Consequently, Lip-FLLL32 suppressed pancreatic cancer cell growth, and exhibited synergetic effects with gemcitabine and radiation treatment in vitro and in vivo. Furthermore, Lip-FLLL32 reduced ALDH1-positive CSC population and modulated several potential stem cell markers. These results demonstrate that Lip-FLLL32 suppresses pancreatic tumor growth and sensitizes pancreatic cancer cells to radiotherapy through inhibition of CSCs in a STAT3-dependent manner. By targeting pancreatic CSCs, Lip-FLLL32 provides a novel strategy for pancreatic cancer therapy via overcoming radioresistance.

A generic 89Zr labeling method to quantify the in vivo pharmacokinetics of liposomal nanoparticles with positron emission tomography

Liposomal nanoparticles are versatile drug delivery vehicles that show great promise in cancer therapy. In an effort to quantitatively measure their in vivo pharmacokinetics, we developed a highly efficient 89Zr liposome-labeling method based on a rapid ligand exchange reaction between the membrane-permeable 89Zr(8-hydroxyquinolinate)4 complex and the hydrophilic liposomal cavity-encapsulated deferoxamine (DFO). This novel 89Zr-labeling strategy allowed us to prepare radiolabeled forms of a folic acid (FA)-decorated active targeting 89Zr-FA-DFO-liposome, a thermosensitive 89Zr-DFO-liposome, and a renal avid 89Zr-PEG-DFO-liposome at room temperature with near-quantitative isolated radiochemical yields of 98%±1% (n=6), 98%±2% (n=5), and 97%±1% (n=3), respectively. These 89Zr-labeled liposomal nanoparticles showed remarkable stability in phosphate-buffered saline and serum at 37°C without leakage of radioactivity for 48 h. The uptake of 89Zr-FA-DFO-liposome by the folate receptor-overexpressing KB cells was almost 15-fold higher than the 89Zr-DFO-liposome in vitro. Positron emission tomography imaging and ex vivo biodistribution studies enabled us to observe the heterogeneous distribution of the 89Zr-FA-DFO-liposome and 89Zr-DFO-liposome in the KB tumor xenografts, the extensive kidney accumulation of the 89Zr-FA-DFO-liposome and 89Zr-PEG-DFO-liposome, and the different metabolic fate of the free and liposome-encapsulated 89Zr-DFO. It also unveiled the poor resistance of all three liposomes against endothelial uptake resulting in their catabolism and high uptake of free 89Zr in the skeleton. Thus, this technically simple 89Zr-labeling method would find widespread use to guide the development and clinical applications of novel liposomal nanomedicines.

Epigenetics and cardiovascular risk in childhood

Cardiovascular disease (CVD) can arise at the early stages of development and growth. Genetic and environmental factors may interact resulting in epigenetic modifications with abnormal phenotypic expression of genetic information without any change in the nucleotide sequence of DNA. Maternal dietary imbalance, inadequate to meet the nutritional needs of the fetus can lead to intrauterine growth retardation, decreased gestational age, low birth weight, excessive post-natal growth and metabolic alterations, with subsequent appearance of CVD risk factors. Fetal exposure to high cholesterol, diabetes and maternal obesity is associated with increased risk and progression of atherosclerosis. Maternal smoking during pregnancy and exposure to various environmental pollutants induce epigenetic alterations of gene expression relevant to the onset or progression of CVD. In children with hypercholesterolemia and/or obesity, oxidative stress activates platelets and monocytes, which release proinflammatory and proatherogenic substances, inducing endothelial dysfunction, decreased Doppler flow-mediated dilation and increased carotid intima-media thickness. Primary prevention of atherosclerosis should be implemented early. It is necessary to identify, through screening, high-risk apparently healthy children and take care of them enforcing healthy lifestyle (mainly consisting of Mediterranean diet and physical activity), prescribing nutraceuticals and eventual medications, if required by a high-risk profile. The key issue is the restoration of endothelial function in the reversible stage of atherosclerosis. Epigenetics may provide new markers for an early identification of children at risk and thereby develop innovative therapies and specific nutritional interventions in critical times.

Cancer Nanotechnology: Opportunities for Prevention, Diagnosis, and Therapy

Nanotechnological innovations over the last 16 years have brought about the potential to revolutionize specific therapeutic drug delivery to cancer tissue without affecting normal tissues. In addition, there are new nanotechnology-based platforms for diagnosis of cancers and for theranostics, i.e., integrating diagnosis with therapy and follow-up of effectiveness of therapy. This chapter presents an overview of these nanotechnology-based advancements in the areas of prevention, diagnosis, therapy, and theranostics for cancer. In addition, we stress the need to educate bio- and medical students in the field of nanotechnology.

Reaction of Lymphoid Organs to Injection of Iron-Carbon Nanoparticles

The distribution of iron-carbon nanoparticles in FeC-DSPE-PEG-2000 modification (micellar particles with structure (Fe) core-carbon shell; PEG-based coating) is studied. The greater part of the nanoparticles accumulated in the spleen and liver, a small amount in the lungs, and the minimum amount in the thymus. The structural changes in the lymphoid organs were minor and involved only the microcirculatory bed. Analysis of the peripheral blood showed manifest anemia, thrombocytopenia, and leukocytosis.

Modulated cellular delivery of anti-VEGF siRNA (bevasiranib) by incorporating supramolecular assemblies of hydrophobically modified polyamidoamine dendrimer in stealth liposomes

A novel lipopolymer based system was designed and characterized for cellular delivery of anti-VEGF siRNA in SKBR-3 breast tumor cell line. Polyamidoamine (PAMAM) dendrimers of low generations (G1, G2 and G3) were incorporated into polyethylene glycol (PEG)-stabilized liposomes by following the consecutive steps: (a) synthesis of the cholesterol conjugates (40% molar ratio of cholesterol to primary amines of PAMAM), (b) incorporation of the conjugates in liposome by lipid mixing and (c) microencapsulation of the siRNA using the ethanol drop method. The cholesterol conjugates of PAMAM dendrimers (G1-Chol40%, G2-Chol40% and G3-Chol40%) formed self assembly with low CMC values (<11μg/ml). Not only did G2-Chol40% show the highest lipid mixing among the cholesterol conjugates, but also, had the lowest leakage of encapsulated carboxyfluorescein tracer. Various N(amine))/L(lipid)/P(phosphate) mole ratios were investigated for siRNA condensation by ethidium bromide dye exclusion assay. The optimum N/L/P ratio of 20:33:10 was chosen for microencapsulation of anti-VEGF siRNA by ethanol drop method, showing particle size of 130nm, zeta-potential of +4mV, siRNA loading efficiency and capacity of 96% and 13wt%, and high stability against heparin sulfate (extracellular matrix). TEM shows uniform and discrete oligo- or multi-lamellar vesicular structures. The liposome incorporating G2-Chol40% was successfully internalized into SKBR-3 cells mainly through clathrin-mediated endocytosis, which was able to escape from endosomes and showed a significantly higher sequence-specific inhibition of VEGF expression and cell growth than the respective G2-Chol40%/siRNA dendriplexes. Importantly, the cytotoxicity decreased with incorporation of G2-Chol40% in the liposomes.

Potential antitumor activity of novel DODAC/PHO-S liposomes

In recent studies, we showed that synthetic phosphoethanolamine (PHO-S) has a great potential for inducing cell death in several tumor cell lines without damage to normal cells. However, its cytotoxic effect and selectivity against tumor cells could increase with encapsulation in cationic liposomes, such as dioctadecyldimethylammonium chloride (DODAC), due to electrostatic interactions between these liposomes and tumor cell membranes. Our aim was to use cationic liposomes to deliver PHO-S and to furthermore maximize the therapeutic effect of this compound. DODAC liposomes containing PHO-S (DODAC/PHO-S), at concentrations of 0.3-2.0 mM, prepared by ultrasonication, were analyzed by scanning electron microscopy (SEM) and dynamic light scattering. The cytotoxic effect of DODAC/PHO-S on B16F10 cells, Hepa1c1c7 cells, and human umbilical vein endothelial cells (HUVECs) was assessed by MTT assay. Cell cycle phases of B16F10 cells were analyzed by flow cytometry and the morphological changes by SEM, after treatment. The liposomes were spherical and polydisperse in solution. The liposomes were stable, presenting an average of ∼ 50% of PHO-S encapsulation, with a small reduction after 40 days. DODAC demonstrated efficient PHO-S delivery, with the lowest values of IC50% (concentration that inhibits 50% of the growth of cells) for tumor cells, compared with PHO-S alone, with an IC50% value of 0.8 mM for B16F10 cells and 0.2 mM for Hepa1c1c7 cells, and without significant effects on endothelial cells. The Hepa1c1c7 cells showed greater sensitivity to the DODAC/PHO-S formulation when compared to B16F10 cells and HUVECs. The use of DODAC/PHO-S on B16F10 cells induced G2/M-phase cell cycle arrest, with the proportion significantly greater than that treated with PHO-S alone. The morphological analysis of B16F10 cells by SEM showed changes such as "bleb" formation, cell detachment, cytoplasmic retraction, and apoptotic bodies after DODAC/PHO-S treatment. Cationic liposomal formulation for PHO-S delivery promoted cytotoxicity more selectively and effectively against B16F10 and Hepa1c1c7 cells. Thus, the DODAC/PHO-S liposomal formulation presents great potential for preclinical studies.

CXCR4-antagonist Peptide R-liposomes for combined therapy against lung metastasis

The chemokine CXCL12 activates CXCR4, initiating multiple pathways that control immune cell trafficking, angiogenesis and embryogenesis; CXCR4 is also overexpressed in multiple tumors affecting metastatic dissemination. While there has been great enthusiasm for exploiting the CXCR4-CXCL12 axis as a target in cancer therapy, to date the promise has yet to be fulfilled. A new class of CXCR4-antagonist cyclic peptides was recently developed and the compound named Peptide R was identified as the most active. With the intent to improve the efficacy and biodistribution of Peptide R, stealth liposomes decorated with Peptide R were developed (PL-Peptide R). In vitro PL-Peptide R efficiently inhibited CXCR4-dependent migration and in vivo it significantly reduced lung metastases and increased overall survival in B16-CXCR4 injected C57BL/6 mice. To evaluate if PL-Peptide R could also be a drug delivery system for CXCR4 expressing tumors, the PL-Peptide R was loaded with doxorubicin (DOX) (PL-Peptide R-DOX). PL-Peptide R-DOX efficiently delivered DOX to CXCR4 expressing cell lines with a consequent decrease in the DOX IC50 efficient dose. In vivo, B16-CXCR4 injected C57BL/6 mice treated with PL-Peptide R-DOX developed fewer lung metastases compared to PL-DOX treated mice. This work provides the proof-of-concept to prevent metastasis by using combined nanomedicine.

High-Throughput Continuous Flow Production of Nanoscale Liposomes by Microfluidic Vertical Flow Focusing

Liposomes represent a leading class of nanoparticles for drug delivery. While a variety of techniques for liposome synthesis have been reported that take advantage of microfluidic flow elements to achieve precise control over the size and polydispersity of nanoscale liposomes, with important implications for nanomedicine applications, these methods suffer from extremely limited throughput, making them impractical for large-scale nanoparticle synthesis. High aspect ratio microfluidic vertical flow focusing is investigated here as a new approach to overcoming the throughput limits of established microfluidic nanoparticle synthesis techniques. Here the vertical flow focusing technique is utilized to generate populations of small, unilamellar, and nearly monodisperse liposomal nanoparticles with exceptionally high production rates and remarkable sample homogeneity. By leveraging this platform, liposomes with modal diameters ranging from 80 to 200 nm are prepared at production rates as high as 1.6 mg min(-1) in a simple flow-through process.

Injectable liposomal formulations of opiorphin as a new therapeutic strategy in pain management

BACKGROUND

Conventional and PEGylated liposomes were developed, aimed at improving the pain-killing effect of opiorphin.

METHODS

The antinociceptive action of the formulations was investigated on rats (tail-flick test), and compared with that of opiorphin and morphine aqueous solutions (all at 5 mg/kg).

RESULTS

Opiorphin loading in conventional liposomes enabled a 28% AUC increase with respect to free peptide. PEGylated liposomes provided AUC values 80, 60 and 40% higher than free peptide, morphine and opiorphin-loaded conventional liposomes, respectively. Moreover, opiorphin entrapment in PEGylated liposomes increased analgesic effect duration by more than 50%. These results were attributed to the greater effectiveness of PEGylated liposomes in protecting the drug and prolonging its circulation time.

CONCLUSION

Opiorphin-loaded PEGylated-liposomes can represent a valid alternative to morphine in pain management.

Effect of particle size on oral absorption of carvedilol nanosuspensions: in vitro and in vivo evaluation

The purpose of this work was to explore the particle size reduction effect of carvedilol on dissolution and absorption. Three suspensions containing different sized particles were prepared by antisolvent precipitation method or in combination with an ultrasonication process. The suspensions were characterized for particle size, surface morphology, and crystalline state. The crystalline form of carvedilol was changed into amorphous form after antisolvent precipitation. The dissolution rate of carvedilol was significantly accelerated by a reduction in particle size. The intestinal absorption of carvedilol nanosuspensions was greatly improved in comparison with microsuspensions and solution in the in situ single-pass perfusion experiment. The in vivo evaluation demonstrated that carvedilol nanosuspensions and microsuspensions exhibited markedly increased C_max (2.09- and 1.48-fold) and AUC_0−t (2.11- and 1.51-fold), and decreased T_max (0.34- and 0.48-fold) in contrast with carvedilol coarse suspensions. Moreover, carvedilol nanosuspensions showed good biocompatibility with the rat gastric mucosa in in vivo gastrointestinal irritation test. The entire results implicated that the dissolution rate and the oral absorption of carvedilol were significantly affected by the particle size. Particle size reduction to form nanosized particles was found to be an efficient method for improving the oral bioavailability of carvedilol.

Hyperthermia approaches for enhanced delivery of nanomedicines to solid tumors

Drug delivery to solid tumors has received much attention in order to reduce harmful side effects and improve the efficacy of treatment. Different strategies have been utilized with nanoparticle drug delivery systems, or nanomedicines, including passive and active targeting strategies, as well as the incorporation of stimuli sensitivity. Additionally, hyperthermia has been used in combination with such systems to further improve accumulation, localization, penetration, and subsequently efficacy. Localized hyperthermia within the solid tumor tissue can be applied through different mechanisms able to trigger vascular and cellular mechanisms for enhanced delivery of nanomedicines. This review covers the use of nanoparticles in drug delivery, the different methods for inducing localized hyperthermia, combination effects of hyperthermia, and successful strategies for improving the delivery of nanomedicines using hyperthermia.

Resveratrol nanoformulations: challenges and opportunities

Resveratrol, a naturally occurring polyphenol and phytoalexin, has received significant attention in recent years due to its vast therapeutic effects including anticancer, antioxidant and anti-inflammatory effects. However, poor pharmacokinetic properties such as low aqueous solubility, low photostability and extensive first pass metabolism result in poor bioavailability, hindering its immense potential. Conventional dosage forms such as dry powder capsules and injections have met with limited success, demonstrating challenges faced in developing an effective formulation. Recently, nanotechnology-based formulations (nanoformulations) are being looked upon as a novel method for improving the pharmacokinetic properties, as well as enhancing targetability and bioavailability of resveratrol. This review outlines the therapeutic potential of resveratrol, explores its mechanisms of action and pharmacokinetic limitations, and discusses the success and challenges of resveratrol-encapsulated nanoparticles in the last decade. Potential techniques to improve encapsulation of the drug within nanoparticles, thereby enhancing its clinical potential are highlighted.

Liposomes in tissue engineering and regenerative medicine

Liposomes are vesicular structures made of lipids that are formed in aqueous solutions. Structurally, they resemble the lipid membrane of living cells. Therefore, they have been widely investigated, since the 1960s, as models to study the cell membrane, and as carriers for protection and/or delivery of bioactive agents. They have been used in different areas of research including vaccines, imaging, applications in cosmetics and tissue engineering. Tissue engineering is defined as a strategy for promoting the regeneration of tissues for the human body. This strategy may involve the coordinated application of defined cell types with structured biomaterial scaffolds to produce living structures. To create a new tissue, based on this strategy, a controlled stimulation of cultured cells is needed, through a systematic combination of bioactive agents and mechanical signals. In this review, we highlight the potential role of liposomes as a platform for the sustained and local delivery of bioactive agents for tissue engineering and regenerative medicine approaches.