Cancer Therapy with Nanotechnology-Based Drug Delivery Systems: Applications and Challenges of Liposome Technologies for Advanced Cancer Therapy

Zoledronic acid-loaded lipidic nanoparticles enhance apoptosis and attenuate invasiveness by inhibiting epithelial to mesenchymal transition (EMT) in HepG2 cancer cells

The aim of this study was to evaluate the potential of zoledronic acid (ZOL)-loaded lipidic nanoparticles (ZOL-NLCs) in enhancing the efficiency of paclitaxel (Pac) in the context of cytotoxicity, apoptosis, and invasiveness of HepG₂ hepatocellular carcinoma cells. ZOL-NLCs were characterized in terms of zeta potential, particle size, and scanning electron microscope (SEM) as well as cell internalization. To measure the anti-proliferative effects of ZOL-NLCs, annexin-V/PI and MTT assays were employed. Real-time PCR and western blot analysis were performed to identify the molecular mechanisms underlying the apoptosis in response to the studied conditions. Furthermore, the transwell migration assay was applied to clarify the role of applied formulations on the invasiveness of HepG₂ cells. Our results demonstrated that the optimized ZOL had an average particle size of 105 ± 6 nm with a nearly narrow size distribution. The IC₅₀ values for ZOL and ZOL-NLCs were 90 ± 3.1 and 54.6 ± 2.4 µM, respectively. The population of apoptotic cells was increased from 17 ± 2% to 27 ± 4% (p < 0.05) in response to treatment with ZOL-NLCs. ZOL-loaded nanoparticles triggered the mRNA expression of Bax as pro-apoptotic marker and E-cadherin as epithelial one along with a decrease in mesenchymal marker, N-cadherin, and Bcl-xl as an anti-apoptotic marker in HepG₂ cells. These outcomes were consistent with western blot analysis of protein expressions. Besides, ZOL-incorporated lipidic nanoparticles reduced the migration of HepG₂ cells significantly. Our data suggest that the formulation of ZOL into lipidic nanoparticles can be considered a potential therapeutic approach that can enhance the efficacy of Pac chemotherapy.

Single-chain antibody-decorated Au nanocages@liposomal layer nanoprobes for targeted SERS imaging and remote-controlled photothermal therapy of melanoma cancer cells

The development of theranostic platforms combining surface-enhanced Raman spectroscopy (SERS) imaging with NIR-stimulated photothermal therapy (PTT) is of utmost importance for the precise diagnosis and selective treatment of cancers, especially in superficial solid tumors. For this purpose, a versatile theranostic nanoprobe of liposomal layer-coated Au nanocages (AuNCs) was decorated with an anti-MUC18 single-chain antibody (scFv). 4-mercapto benzoic acid (p-MBA)-labeled AuNCs (p-AuNCs) were coated by a liposomal layer (p-AuNCs@lip), followed by conjugating anti-MUC18 scFv via post-insertion method to form immuno-liposomal layer-coated AuNCs (p-AuNCs@scFv-lip). Physicochemical characterizations of the p-AuNCs@scFv-lip were investigated by transmission electron microscopy (TEM) and UV-vis and Raman spectroscopy. Furthermore, the targeting ability and theranostic efficiency of the nanoprobe were evaluated for specific diagnosis and treatment of cancerous melanoma cells by flow cytometry, SERS mapping, and live/dead assay. The formation of lipid layer on p-AuNCs surface was confirmed by TEM imaging. After decorating the liposomal layer with scFv, a relevant red shift was observed in the UV-vis spectrum. Moreover, p-AuNCs@lip presented characteristic peaks in the Raman spectrum, which exhibited only a minor change after scFv conjugation (p-AuNCs@scFv-lip). Interestingly, the cellular uptake of AuNCs@scFv-lip by A375 cell line (MUC18⁺) showed a 24-fold enhancement compared with SKBR3 cells (MUC18^-). AuNCs@scFv-lip specifically identified A375 cells from SKBR cells via SERS mapping and effectively killed A375 cells through the PTT mechanism. Taken together, this theranostic platform can provide a promising tool for both in situ diagnosis and remote-controlled thermal ablation of cancer cells.

Biomedical potentialities of cationic geminis as modulating agents of liposome in drug delivery across biological barriers and cellular uptake

Hydroxyethyl bearing gemini surfactants, alkanediyl-α,ω-bis(N-hexadecyl-N-2-hydroxyethyl-N-methylammonium bromide), 16-s-16(OH), were used to augment phosphatidylcholine based liposomes to achieve higher stability and enhanced cellular uptake and penetration. The developed liposomes were loaded with rhodamine B, doxorubicin hydrochloride, pralidoxime chloride to investigate release properties, cytotoxicity in vitro, as well as ability to cross the blood-brain barrier. At molar ratio of 35:1 (lipid:surfactant) the formulation was found to be of low toxicity, stable for two months, and able to deliver rhodamine B beyond the blood-brain barrier in rats. In vivo, pharmacokinetics of free and formulated 2-PAM in plasma and brain were evaluated, liposomal 2-PAM was found to reactivate 27% of brain acetylcholinesterase, which is, to our knowledge, the first example of such high degree of reactivation after intravenous administration of liposomal drug.

Cell targeting peptides as smart ligands for targeting of therapeutic or diagnostic agents: a systematic review

Cell targeting peptides (CTP) are small peptides which have high affinity and specificity to a cell or tissue targets. They are typically identified by using phage display and chemical synthetic peptide library methods. CTPs have attracted considerable attention as a new class of ligands to delivery specifically therapeutic and diagnostic agents, because of the fact they have several advantages including easy synthesis, smaller physical sizes, lower immunogenicity and cytotoxicity and their simple and better conjugation to nano-carriers and therapeutic or diagnostic agents compared to conventional antibodies. In this systematic review, we will focus on the basic concepts concerning the use of cell-targeting peptides (CTPs), following the approaches of selecting them from peptide libraries. We discuss several developed strategies for cell-specific delivery of different cargos by CTPs, which are designed for drug delivery and diagnostic applications.

Direct Tracking of Particles and Quantification of Margination in Blood Flow

Margination refers to the migration of particles toward blood vessel walls during blood flow. Understanding the mechanisms that lead to margination will aid in tailoring the attributes of drug-carrying particles for effective drug delivery. Most previous studies evaluated the margination propensity of these particles via an adhesion mechanism, i.e., by measuring the number of particles that adhered to the channel wall. Although particle adhesion and margination are related, adhesion also depends on other factors. In this study, we quantified the margination propensity of particles of varying diameters (0.53, 0.84, and 2.11 μm) and apparent wall shear rates (30, 61, and 121 s^-1) by directly tracking fluorescent particles flowing through a microfluidic channel. The margination parameter, M, is defined as the total number of particles found within the cell-free layers normalized by the total number of particles that passed through the channel. In this study, an M-value of 0.2 indicated no margination, which was observed for all particle sizes in water. In the case of blood, larger particles were found to have higher M-values and thus marginated more effectively than smaller particles. The corresponding M-values at the device outlet were 0.203, 0.223, and 0.285 for 0.53-, 0.84-, and 2.11-μm particles, respectively. At the inlet, the M-values for all particle sizes in blood were <0.2, suggesting that non-fully-developed flow and constriction may lead to demargination. For particle velocities transverse to the flow direction (v_y), all particle sizes showed a larger standard deviation of v_y as well as a higher effective diffusivity when the particles were suspended in blood relative to water. These higher values are attributed to collisions between the blood cells and particles, further supporting recent simulation results. In terms of flow rates, for a given particle size, the higher the flow rate, the higher the M-value.

Liposomes as colloidal nanovehicles: on the road to success in intravenous drug delivery

The advancement of research in colloidal systems has led to the increased application of this technology in more effective and targeted drug delivery. Nanotechnology enables control over functionality parameters and allows innovations in biodegradable, biocompatible, and stimuli-responsive delivery systems. The first closed bilayer phospholipid system, the liposome system, has been making steady progress over five decades of extensive research and has been efficient in achieving many desirable parameters such as remote drug loading, size-controlling measures, longer circulation half-lives, and triggered release. Liposome-mediated drug delivery has been successful in overcoming obstacles to cellular and tissue uptake of drugs with improved biodistribution in vitro and in vivo. These colloidal nanovehicles have moved on from a mere concept to clinical applications in various drug delivery systems for antifungal, antibiotic, and anticancer drugs.

Liposomal Drug Product Development and Quality: Current US Experience and Perspective

Research in the area of liposomes has grown substantially in the past few decades. Liposomes are lipid bilayer structures that can incorporate drug substances to modify the drug's pharmacokinetic profile thereby improving drug delivery. The agency has received over 400 liposomal drug product submissions (excluding combination therapies), and there are currently eight approved liposomal drug products on the US market. In order to identify the pain points in development and manufacturing of liposomal drug products, a retrospective analysis was performed from a quality perspective on submissions for new and generic liposomal drug products. General analysis on liposomal drug product submissions was also performed. Results indicated that 96% of the submissions were Investigational New Drug (IND) applications, 3% were New Drug Applications (NDAs), and the remaining 1% was Abbreviated New Drug Applications (ANDAs). Doxorubicin hydrochloride was the most commonly used drug substance incorporated into the liposomes (31%). The majority of the liposomal products were administered via intravenous route (84%) with cancer (various types) being the most common indication (63%). From a quality perspective, major challenges during the development of liposomal drug products included identification and (appropriate) characterization of critical quality attributes of liposomal drug products and suitable control strategies during product development. By focusing on these areas, a faster and more efficient development of liposomal drug products may be achieved. Additionally, in this way, the drug review process for such products can be streamlined.

Sustained release of melatonin: A novel approach in elevating efficacy of tamoxifen in breast cancer treatment

BACKGROUND

Finding advanced anti-cancer agents with selective toxicity in tumor tissues is the goal of anticancer delivery systems. This study investigated potential application of nanostructured lipid carriers (NLCs) in increasing melatonin induced cytotoxicity and apoptosis in MCF-7 breast cancer cells.

METHODS

Melatonin-loaded NLCs were characterized for particle size, zeta potential, Fourier transforms infrared spectroscopy, differential scanning calorimetry, cellular uptake, and scanning electron microscope (SEM). Anti-proliferative and apoptotic effects of new formulation were evaluated by MTT and flow cytometric assays, respectively. Gene expression of apoptotic markers including survivin, Bcl-2 and Bid were examined by Real time quantitative PCR.

RESULTS

The optimized formulation of NLCs revealed mean particle size of 71±5nm with nearly narrow size distribution. The formulation exhibited an acceptable stability during four months in terms of size and lack of drug release. The IC50 values for melatonin and tamoxifen were 1.3±0.4mM and 30.7±5.2μM, respectively. Melatonin loaded NLCs decreased percentage of cell proliferation from 55±7.2% to 40±4.1% (p<0.05). Co-treatment of the cells with melatonin loaded nanoparticles and tamoxifen caused two fold increase in the percentage of apoptosis (p<0.05). Evaluation of gene expression profile demonstrated a marked decrease in anti-apoptotic survivin with increase in pro-apoptotic Bid mRNA levels.

CONCLUSION

Taken together, our results suggest NLC technology as a promising delivery system, which elevates the efficacy of chemotherapeutics in breast cancer cells.

Small molecule therapeutic-loaded liposomes as therapeutic carriers: from development to clinical applications

In this review, various methods and mechanisms for encapsulation of small therapeutic molecules in liposomes for targeted delivery and triggered release, as well as their potential in the clinical uses, are discussed.

Smart multifunctional nanoparticles in nanomedicine

Recent advances in nanotechnology caused a growing interest using nanomaterials in medicine to solve a number of issues associated with therapeutic agents. The fabricated nanomaterials with unique physical and chemical properties have been investigated for both diagnostic and therapeutic applications. Therapeutic agents have been combined with the nanoparticles to minimize systemic toxicity, increase their solubility, prolong the circulation half-life, reduce their immunogenicity and improve their distribution. Multifunctional nanoparticles have shown great promise in targeted imaging and therapy. In this review, we summarized the physical parameters of nanoparticles for construction of “smart” multifunctional nanoparticles and their various surface engineering strategies. Outlook and questions for the further researches were discussed.