Barriers and Strategies of Cationic Liposomes for Cancer Gene Therapy

Exploring the promise of lipoplexes: From concept to clinical applications

Lipoplexes are non-viral lipid vectors that effectively form complexes with genetic material, positioning them as promising alternatives to viral vectors in gene therapy. Their advantages include lower toxicity, reduced immunogenicity, improved targetability, and ease of large-scale production. A typical lipoplex is composed of cationic lipids, neutral lipids, and anionic nucleic acids (e.g., DNA, mRNA, miRNA, siRNA, shRNA). Neutral lipids play an auxiliary role and are often used as transfection enhancers. Enhancing lipoplex efficiency often involves modifying the cationic lipid structure through functional groups like PEG polymers and targeting ligands. The assembly of lipoplexes occurs spontaneously. This process involves the binding of the positively charged polar head group of the cationic lipid to the negatively charged DNA spontaneously as a result of electrostatic interaction, then irreversible rearrangement and condensation of the lipoplex occurs to form either lamellar or hexagonal structures. The transfection process encompasses several steps: cellular entry, endosomal escape and cargo release, cytoplasmic trafficking, and nuclear entry. The physicochemical and biological properties of lipoplexes are influenced by factors such as lipid structure, charge ratio, and environmental conditions. Despite certain limitations like low gene transfer efficiency and rapid clearance by serum proteins, lipoplexes show promise for clinical applications. They can be administered through various routes, offering potential treatments for diseases such as cancer, bone damage, infection, and cystic fibrosis. The study aims to examine the potential of lipoplexes as a promising vehicle for delivering therapeutic agents and their progression from theoretical concepts to practical clinical applications.

STING-activating layered double hydroxide nano-adjuvants for enhanced cancer immunotherapy

Cancer vaccines represent a promising therapeutic strategy in oncology, yet their effectiveness is often hampered by suboptimal antigen targeting, insufficient induction of cellular immunity, and the immunosuppressive tumor microenvironment. Advanced delivery systems and potent adjuvants are needed to address these challenges, though a restricted range of adjuvants for human vaccines that are approved, and even fewer are capable of stimulating robust cellular immune response. In this work, we engineered a unique self-adjuvanted platform (MLDHs) by integrating STING agonists manganese into a layered double hydroxide nano-scaffold, encapsulating the model antigen ovalbumin (OVA). The MLDHs platform encompasses Mn-doped MgAl-LDH (MLMA) and Mn-doped MgFe-LDH (MLMF). Upon subcutaneous injection, OVA/MLDHs specifically accumulated within lymph nodes (LNs), where they were internalized by resident antigen-presenting cells. The endosomal degradation of MLDHs facilitated the cytoplasmic release of antigen and Mn2+, promoting cross-presentation and triggering the STING pathway, which in turn induced a potent cellular immune response against tumors. Notably, OVA/MLMF induced stronger M1 macrophage polarization and a more potent T-cell response within tumor-infiltrating lymphocytes compared to OVA/MLMA, leading to significant tumor regression in B16F10-OVA bearing mice with minimal adverse effects. Additionally, combining MLMF with the vascular disrupting agent Vadimezan disrupted the tumor's central region, typically resistant to immune cell infiltration, further extending survival in tumor-bearing mice. This innovative strategy may show great potential for improving cancer immunotherapy and offers hope for more effective treatments in the future.

Advances in Liposomal Interleukin and Liposomal Interleukin Gene Therapy for Cancer: A Comprehensive Review of Preclinical Studies

BACKGROUND

Preclinical studies on liposomal interleukin (IL) therapy demonstrate considerable promise in cancer treatment. This review explores the achievements, challenges, and future potential of liposomal IL encapsulation, focusing on preclinical studies.

METHODS

A structured search was conducted using the PubMed and Web of Science databases with the following search terms and Boolean operators: ("liposomal interleukin" OR "liposome-encapsulated interleukin") AND ("gene therapy" OR "gene delivery") AND ("cancer" OR "tumor" OR "oncology") AND ("pre-clinical studies" OR "animal models" OR "in vitro studies".

RESULTS

Liposomal IL-2 formulations are notable for enhancing delivery and retention at tumor sites. Recombinant human interleukin (rhIL-2) adsorbed onto small liposomes (35-50 nm) substantially reduces metastases in murine models. Hepatic metastasis models demonstrate superior efficacy of liposomal IL-2 over free IL-2 by enhancing immune responses, particularly in the liver. Localized delivery strategies, including nebulized liposomal IL-2 in canine pulmonary metastases and intrathoracic administration in murine sarcoma models, reduce systemic toxicity while promoting immune activation and tumor regression. Liposomal IL gene therapy, delivering cytokine genes directly to tumor sites, represents a notable advancement. Combining IL-2 gene therapy with other cytokines, including IL-6 or double-stranded RNA adjuvants, synergistically enhances macrophage and T-cell activation. Liposomal IL-4, IL-6, and IL-21 therapies show potential across various tumor types. Pairing liposomal IL-2 with chemotherapy or immune agents improves remission and survival. Innovative strategies, including PEGylation and ligand-targeted systems, optimize delivery, release, and therapeutic outcomes.

CONCLUSIONS

Utilizing immune-stimulatory ILs through advanced liposomal delivery and gene therapy establishes a strong foundation for advancing cancer immunotherapy.

Exosome-Inspired Lipid Nanoparticles for Enhanced Tissue Penetration

The extracellular matrix (ECM) is a complex network of biomolecules with varying pore sizes, posing a challenge for the effective penetration of lipid nanoparticles. In contrast, cell-derived lipid nanoparticles, such as exosomes, have demonstrated the ability to travel to distant organs, indicating their capacity to penetrate the ECM. Here, we designed exosome-like vesicles (ELVs) inspired by exosomes' distinct transport phenomena. Specifically, we integrated three exosomal components (anionic lipid, cholesterol, and aquaporin-1) associated with transport into our ELVs to mimic the superior diffusion behavior of exosomes over synthetic lipid nanoparticles. Surprisingly, both bulk- and single-particle-diffusion studies revealed a more than 33 times increase in the effective diffusion coefficient within model ECM compared to conventional lipid nanoparticles. Furthermore, ELVs show an 80% increase in the effective diffusion coefficient within biological tissues. The excellent transport behavior of ELVs was further validated in vivo, where intratumoral injection showcased their superior transport. These findings provide insights into lipid nanoparticle design for improved tissue penetration.

In vivo vectorization and delivery systems for gene therapies and RNA-based therapeutics in oncology

Gene and RNA-based therapeutics represent a promising frontier in oncology, enabling targeted modulation of tumor-associated genes and proteins. This review explores the latest advances in payload vectorization and delivery systems developed for in vivo cancer treatments. We discuss viral and non-viral organic particles, including lipid based nanoparticles and polymeric structures, for the effective transport of plasmids, siRNA, and self-amplifying RNA therapeutics. Their physicochemical properties, strategies to overcome intracellular barriers, and innovations in cell-based carriers and engineered extracellular vesicles are highlighted. Moreover, we consider oncolytic viruses, novel viral capsid modifications, and approaches that refine tumor targeting and immunomodulation. Ongoing clinical trials and regulatory frameworks guide future directions and emphasize the need for safe, scalable production. The potential convergence of these systems with combination therapies paves the way toward personalized cancer medicine.

Injectable Endoplasmin-Loaded Lipid Nanoparticles-Hydrogel Composite for Cartilage Regeneration

BACKGROUND

Endoplasmin (ENPL), a heat shock protein 90 family member, promotes chondrogenic differentiation of stem cells by inhibiting ERK1/2 phosphorylation and inducing endoplasmic reticulum stress. However, its large size limits cellular uptake and therapeutic potential. To overcome this challenge, a cationic lipid nanoparticle (C_LNP) system was designed to deliver ENPL intracellularly, enhancing its effects on human tonsil-derived mesenchymal stem cells (hTMSCs).

METHODS

ENPL-loaded cationic lipid nanoparticles (ENPL_C_LNP) were synthesized to facilitate intracellular ENPL delivery. The delivery efficiency and cytotoxicity were assessed in vitro using hTMSCs. Additionally, ENPL_C_LNPs were incorporated into a hyaluronic acid and chondroitin sulfate-based injectable hydrogel and tested for chondrogenic differentiation potential in a mouse subcutaneous model.

RESULTS

ENPL_C_LNP achieved over 80% intracellular protein delivery efficiency with no cytotoxic effects. Co-cultured hTMSCs exhibited increased glycosaminoglycans (GAGs) and collagen expression over 21 days. In vivo, the hydrogel-embedded ENPL_C_LNP system enabled stable cartilage differentiation, evidenced by abundant cartilage-specific lacuna structures in regenerated tissue.

CONCLUSION

Combining ENPL_C_LNP with an injectable hydrogel scaffold supports chondrogenic differentiation and cartilage regeneration, offering a promising strategy for cartilage tissue engineering.

Innovations in Cancer Therapy: Endogenous Stimuli-Responsive Liposomes as Advanced Nanocarriers

Recent advancements in nanotechnology have revolutionized cancer therapy-one of the most pressing global health challenges and a leading cause of death-through the development of liposomes (L), lipid-based nanovesicles known for their biocompatibility and ability to encapsulate both hydrophilic and lipophilic drugs. More recent innovations have led to the creation of stimuli-responsive L that release their payloads in response to specific endogenous or exogenous triggers. Dual- and multi-responsive L, which react to multiple stimuli, offer even greater precision, improving therapeutic outcomes while reducing systemic toxicity. Additionally, these smart L can adjust their physicochemical properties and morphology to enable site-specific targeting and controlled drug release, enhancing treatment efficacy while minimizing adverse effects. This review explores the latest advancements in endogenous stimuli-responsive liposomal nanocarriers, as well as dual- and multi-responsive L that integrate internal and external triggers, with a focus on their design strategies, mechanisms, and applications in cancer therapy.

Development of ROS-triggered masked liposomes for activated cellular delivery using a charge balance strategy

We report a charge balance strategy for reactive oxygen species (ROS)-triggered activation of liposome cell delivery by unmasking cationic membranes. Zeta potential experiments, microplate-based vesicle interaction assays, and cellular delivery studies confirmed that modification of anionic lipid 1 by ROS led to the uncaging of cationic liposomes, thereby driving cellular association.

Advancing neurological disorders therapies: Organic nanoparticles as a key to blood-brain barrier penetration

The blood-brain barrier (BBB) plays a vital role in protecting the central nervous system (CNS) by preventing the entry of harmful pathogens from the bloodstream. However, this barrier also presents a significant obstacle when it comes to delivering drugs for the treatment of neurodegenerative diseases and brain cancer. Recent breakthroughs in nanotechnology have paved the way for the creation of a wide range of nanoparticles (NPs) that can serve as carriers for diagnosis and therapy. Regarding their promising properties, organic NPs have the potential to be used as effective carriers for drug delivery across the BBB based on recent advancements. These remarkable NPs have the ability to penetrate the BBB using various mechanisms. This review offers a comprehensive examination of the intricate structure and distinct properties of the BBB, emphasizing its crucial function in preserving brain balance and regulating the transport of ions and molecules. The disruption of the BBB in conditions such as stroke, Alzheimer's disease, and Parkinson's disease highlights the importance of developing creative approaches for delivering drugs. Through the encapsulation of therapeutic molecules and the precise targeting of transport processes in the brain vasculature, organic NP formulations present a hopeful strategy to improve drug transport across the BBB. We explore the changes in properties of the BBB in various pathological conditions and investigate the factors that affect the successful delivery of organic NPs into the brain. In addition, we explore the most promising delivery systems associated with NPs that have shown positive results in treating neurodegenerative and ischemic disorders. This review opens up new possibilities for nanotechnology-based therapies in cerebral diseases.

A journey into siRNA therapeutics development: A focus on Pharmacokinetics and Pharmacodynamics

siRNA therapeutics are emerging novel modalities targeting highly specific mRNA via RNA interference mechanism. Its unique pharmacokinetics (PKs) and pharmacodynamics (PDs) are significant challenges for clinical use. Furthermore, naked siRNA is a highly soluble macromolecule with a negative charge, making plasma membrane penetration a significant hurdle. It is also vulnerable to nuclease degradation. Therefore, advanced formulation technologies, such as lipid nanoparticles and N-acetylgalactosamine conjugation, have been developed and are now used in clinical practice to enhance target organ delivery and stability. The innate complex biological mechanisms of siRNA, along with its formulation, are major determinants of the PK/PD characteristics of siRNA products. To systematically and quantitatively understand these characteristics, it is essential to develop and utilize quantitative PK/PD models for siRNA therapeutics. In this review, the effects of formulation on the PKs and PK/PD models of approved siRNA products were presented, highlighting the importance of selecting appropriate biomarkers and understanding formulation, PKs, and PDs for quantitative interpreting the relationship between plasma concentration, organ concentration, biomarkers, and efficacy.

Double Peptide-Functionalized Carboxymethyl Chitosan-Coated Liposomes Loaded with Dexamethasone as a Potential Strategy for Active Targeting Drug Delivery

Liposomes are intensively used as nanocarriers for biology, biochemistry, medicine, and in the cosmetics industry and their non-toxic and biocompatible nature makes these vesicles attractive systems for biomedical applications. Moreover, the conjugation of specific ligands to liposomes increases their cellular uptake and therapeutic efficiency. Considering these aspects, the aim of the present study was to obtain new formulations of cationic liposomes coated with dual-peptide functionalized carboxymethyl chitosan (CMCS) for the treatment of inner ear diseases. In order to achieve efficient active targeting and ensuring a high efficacy of the treatment, CMCS was functionalized with Tet1 peptide, to target specific ear cells, and TAT peptide, to ensure cellular penetration. Furthermore, dexamethasone phosphate was loaded as a model drug for the treatment of ear inflammation. The infrared spectroscopy confirmed the functionalization of CMCS with the two specific peptides. The mean diameter of the uncovered liposomes varied between 167 and 198 nm whereas the CMCS-coated liposomes ranged from 179 to 202 nm. TEM analysis showed the spherical shape and unilamellar structure of liposomes. The release efficiency of dexamethasone phosphate after 24 h from the uncoated liposomes was between 37 and 40% and it appeared that the coated liposomes modulated this release. The obtained results demonstrated that the liposomes are hemocompatible since, for a tested concentration of 100 µg/mL, the liposome suspension had a lysis of erythrocytes lower than 2.5% after 180 min of incubation. In addition, the peptide-functionalized CMCS-coated liposomes induced a non-significant effect on the viability of normal V79-4 cells after 48 h, at the highest doses. Values of 71.31% were recorded (CLCP-1), 77.28% (CLCP-2) and 74.36% (CLCP-3), correlated with cytotoxic effects of 28.69%, 22.72%, and 25.64%.

Impact of PEGylated liposomes on cytotoxicity of tamoxifen and piperine on MCF-7 human breast carcinoma cells

Tamoxifen (TMF) is an anticancer agent used for managing estrogen receptor-positive breast cancer. It has limited therapeutic efficacy against breast cancer, which could be enhanced by the coadministration of herbal drugs like piperine (PIP). However, the hydrophobic nature of TMF and PIP restricts their therapeutic application. Therefore, the present study focuses on the impact of the anticancer activity of TMF in combination with PIP and after entrapping them into liposomes (TMF-PIP-LPs and TMF-PIP-PEG-LPs). The liposomes were prepared using the thin film hydration method. In addition, the morphology of the prepared liposomes was found spherical after SEM and TEM analyses. Further, the in vitro cytotoxicity (IC50) study of pure PIP and TMF was found to be 90.3 ± 10.2 μg/mL and 40.9 ± 5.9 μg/mL, respectively. Interestingly, an improved cytotoxicity (IC50) was observed when the TMF and PIP were loaded into liposomes (TMF-PIP-LPs: 21 ± 1.6 μg/mL and TMF-PIP-PEG-LPs: 10 ± 0.5 μg/mL). Also, the PEGylated liposomes showed improvement in cellular uptake as compared to liposomes without PEGylation in MCF-7 human breast carcinoma cells. Thus, the enhanced cellular uptake and improved cytotoxicity of PEGylated liposomes can be a suitable strategy for delivering TMF with PIP for breast cancer treatment.

Comprehensive analysis of lipid nanoparticle formulation and preparation for RNA delivery

Nucleic acid-based therapeutics are a common approach that is increasingly popular for a wide spectrum of diseases. Lipid nanoparticles (LNPs) are promising delivery carriers that provide RNA stability, with strong transfection efficiency, favorable and tailorable pharmacokinetics, limited toxicity, and established translatability. In this review article, we describe the lipid-based delivery systems, focusing on lipid nanoparticles, the need of their use, provide a comprehensive analysis of each component, and highlight the advantages and disadvantages of the existing manufacturing processes. We further summarize the ongoing and completed clinical trials utilizing LNPs, indicating important aspects/questions worth of investigation, and analyze the future perspectives of this significant and promising therapeutic approach.

Cationic lipid transfection induces nuclear actin filaments

Cationic lipids are widely used for gene delivery. Here, we report the transient formation of nuclear actin filaments in mammalian cells transfected with commercially available transfection reagents regardless of the proteins transfected. Readily detectable with phalloidin, nuclear actin ranges from short filaments to a fully developed network. Nuclear actin filaments persist for hours, peak 20 h after transfection, and may be involved in DNA damage repair.

Exploring the Interfacial Dynamics of Unilamellar and Multilamellar Cationic Liposomes on SiO2 and Their Interactions with Membrane-Active Peptide

Understanding the interplay between lipid assemblies and solid supports is crucial for advancing model membrane systems and biomedical applications. This study investigates the interfacial behaviors of unilamellar and multilamellar cationic liposomes on silicon dioxide and their interactions with a membrane-active AH peptide. Using QCM-D monitoring, unilamellar liposomes were found to rapidly form SLBs through one-step adsorption kinetics, whereas multilamellar liposomes exhibited slower adsorption. Further addition of liposomes caused fusogenic interactions with SLBs, where multilamellar liposomes formed more rigid lipid membranes. Upon AH peptide exposure, unilamellar-based lipid membranes showed higher susceptibility to structural transformations, achieving complete SLB formation, while multilamellar-based lipid membranes displayed reduced sensitivity and retained residual viscoelastic components, indicative of incomplete SLB formation. These findings underscore the significant influence of liposome lamellarity on their interfacial dynamics and peptide interactions, crucial for designing effective lipid-based delivery and sensing systems.

Brief Comparison of the Efficacy of Cationic and Anionic Liposomes as Nonviral Delivery Systems

In recent decades, the development and application of nonviral vectors, such as liposomes and lipidic nanoparticles, for gene therapy and drug delivery have seen substantial progress. The interest in the physicochemical properties and structures of the complexes liposome/DNA and liposome/RNA is due to their potential to substitute viruses as carriers of drugs or genetic material into cells with minimal cytotoxicity, which could lead to their use in gene therapy. Initially, cationic liposomes were utilized as nonviral DNA delivery vectors; subsequently, different molecules, such as polymers, were incorporated to enhance transfection efficiency. Additionally, liposome/protein complexes have been developed as nonviral vectors for the treatment of diseases. The most relevant internalization pathways of these vectors and the few transfection results obtained using targeted and nontargeted liposomes are discussed below. The high cytotoxicity of cationic liposomes represents a significant challenge for the development of gene therapy and drug delivery. Anionic liposomes offer a promising alternative to address the limitations of conventional cationic liposomes, including immune response, short circulation time, and low toxicity. This review will discuss the advantages of cationic liposomes and the novel anionic liposome-based systems that have emerged as a result. The advent of novel designs and manufacturing techniques has facilitated the development of innovative systems, designated as lipid nanoparticles (LNPs), which serve as highly efficacious regulators of the immune system.

Recent advances in polymeric and lipid stimuli-responsive nanocarriers for cell-based cancer immunotherapy

Conventional cancer therapy has major limitations, including non-specificity, unavoidable side effects, low specific tumor accumulation and systemic toxicity. In recent years, more effective and precise treatment methods have been developed, including cell-based immunotherapy. Carriers that can accurately and specifically target cells and equip them to combat cancer cells are particularly important for developing this therapy. As a result, attention has been drawn to smart nanocarriers that can react to specific stimuli. Thus, stimuli-responsive nanocarriers have attracted increasing attention because they can change their physicochemical properties in response to stimulus conditions, such as pH, enzymes, redox agents, hypoxia, light and temperature. This review highlights recent advances in various stimuli-responsive nanocarriers, discussing loading, targeted delivery, cellular uptake, biocompatibility and immunomodulation in cell-based immunotherapy. Finally, future challenges and perspectives regarding the possible clinical translation of nanocarriers are discussed.

Liposomal Formulations of Novel BODIPY Dimers as Promising Photosensitizers for Antibacterial and Anticancer Treatment

Synthesis, photochemical properties, liposomal encapsulation, and in vitro photodynamic activity studies of novel BODIPY dimer connected at meso-meso positions and its brominated and iodinated analogs were described. UV-Vis measurements indicated that the dimeric structure of obtained BODIPYs did not significantly influence the positions of the absorption maxima. Emission properties and singlet oxygen generation studies revealed a strong heavy atom effect of brominated and iodinated BODIPY dimers, manifested by fluorescence intensity reduction and increased singlet oxygen generation ability compared to analog without halogen atoms. For the in vitro photodynamic activity studies, dimers were incorporated into two different types of liposomes: positively charged DOTAP:POPC and negatively charged POPG:POPC. The photoinactivation studies revealed high activity of brominated and iodinated dimers incorporated into DOTAP:POPC liposomes on both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Anticancer studies on human breast adenocarcinoma MDA-MB-231 and human ovarian carcinoma A2780 cells revealed that DOTAP:POPC liposomes containing brominated and iodinated dimers were active even at low nanomolar concentrations. In addition, they were more active against MDA-MB-231 cells than A2780 cells, which is particularly important since the MDA-MB-231 cell line represents triple-negative breast cancer, which has limited therapeutic options.

Box-Behnken design assisted approach in optimizing lipid composition for cationic liposome formulation as gene carrier

BACKGROUND

Cationic liposomes represent a promising non-viral carrier platform for gene delivery. The successful intracellular delivery of genes to the target cell is highly influenced by lipid compositions in the liposomal formulation. In the present study, a Box-Behnken design was applied to investigate the optimal lipid composition for the liposome-based transfection agent.

METHODS

The concentrations of DOTAP, DSPE-PEG, and cholesterol were set as independent factors. A total of 15 lipid compositions were generated and tested for specific responses, including particle size, encapsulation efficiency, cell viability, and cell transfection. The data were then analyzed to predict the optimal composition using response surface methodology (RSM).

RESULTS

The results for particle size, encapsulation efficiency, cell viability and fluorescence intensity ranged from 158.7 to 2064 nm, 48.19-95.72%, 81.50-122.67%, and 0.0-9.08, respectively. Compositions of liposome-based transfection agent without DOTAP, those without cholesterol, and those containing DSPE-PEG2000 with a molar ratio equal to or greater than that of cholesterol tended to exhibit low encapsulation efficiency. The ability of the liposome to complex DNA, as determined through electrophoresis gel retardation assay, showed that the composition without DOTAP produced DNA bands, indicating that the prepared liposomes had a less ability to complex DNA. The cytotoxicity test results indicated that all lipid compositions were considered non-toxic, as they exhibited >80% cell viability. The cell transfection assay demonstrated that the lipid composition containing a combination of DOTAP and cholesterol was able to transfect DNA into cells. According to response analysis, RSM predicted that the optimal lipid composition consisted of 2.75 μmol DOTAP and 0.91 μmol cholesterol, with a desirability value of 0.85.

CONCLUSIONS

Although the equation model is still acceptable for predicting the optimal lipid composition, further study is needed to obtain a model with higher desirability, such as by using more lipid compositions, increased replications, and different variable responses.

Lipid-Based Nanoformulations for Drug Delivery: An Ongoing Perspective

Oils and lipids help make water-insoluble drugs soluble by dispersing them in an aqueous medium with the help of a surfactant and enabling their absorption across the gut barrier. The emergence of microemulsions (thermodynamically stable), nanoemulsions (kinetically stable), and self-emulsifying drug delivery systems added unique characteristics that make them suitable for prolonged storage and controlled release. In the 1990s, solid-phase lipids were introduced to reduce drug leakage from nanoparticles and prolong drug release. Manipulating the structure of emulsions and solid lipid nanoparticles has enabled multifunctional nanoparticles and the loading of therapeutic macromolecules such as proteins, nucleic acid, vaccines, etc. Phospholipids and surfactants with a well-defined polar head and carbon chain have been used to prepare bilayer vesicles known as liposomes and niosomes, respectively. The increasing knowledge of targeting ligands and external factors to gain control over pharmacokinetics and the ever-increasing number of synthetic lipids are expected to make lipid nanoparticles and vesicular systems a preferred choice for the encapsulation and targeted delivery of therapeutic agents. This review discusses different lipids and oil-based nanoparticulate systems for the delivery of water-insoluble drugs. The salient features of each system are highlighted, and special emphasis is given to studies that compare them.

Design optimization of Fucoidan-coating Cationic Liposomes for enhance Gemcitabine delivery

Obstacles facing chemotherapeutic drugs for cancers led scientists to load Gemcitabine (GEM) into nanocarriers like liposomes, known for their nontoxicity profile and targeting capacity. The liposomal nanostructures containing GEM were coated with Fucoidan (FU) due to its anti-tumor properties by targeting cancer cells. Thus four different cationic liposomes formulations were prepared by thin-film hydration method in optimal conditions: DOTAP (formulation A); DPPC/DOTAP (4:1 molar ratio, formulation B), DPPC/DMPC/DOTAP (4:1:1 molar ratio, formulation C) and DPPC/DMPC/DOTAP/DSPE-mPEG2000 (4:1:1:0.1 molar ratio, formulation D). They were studied to identify lipid-compositions offering effective GEM-entrapment and successful coating of FU on the liposome surface. Additional qualitative characteristics, such as particle size, polydispersity index, zeta potential, stability and in vitro drug release were then evaluated. Formulation C gave the best GEM-entrapment efficiency (EE) but formed aggregates when coated with FU, giving non-homogenous large size particles then not suitable for effective delivery. It was the same situation with formulation A and B. Only the formulation D showed a good GEM-EE (> 80%) and affinity by successful coating FU from three different algae species. The PEGylated formulation D coated of FU, with regard to storage stability and drug release studies, revealed to be a promising approach on design of optimal drug delivery system.

Lipid- and Polymer-Based Nanocarrier Platforms for Cancer Vaccine Delivery

Cancer immunotherapy has gained popularity in recent years in the search for effective treatment modalities for various malignancies, particularly those that are resistant to conventional chemo- and radiation therapy. Cancer vaccines target the cancer-immunity cycle by boosting the patient's own immune system to recognize and kill cancer cells, thus serving as both preventative and curative therapeutic tools. Among the different types of cancer vaccines, those based on nanotechnology have shown great promise in advancing the field of cancer immunotherapy. Lipid-based nanoparticles (NPs) have become the most advanced platforms for cancer vaccine delivery, but polymer-based NPs have also received considerable interest. This Review aims to provide an overview of the nanotechnology-enabled cancer vaccine landscape, focusing on recent advances in lipid- and polymer-based nanovaccines and their hybrid structures and discussing the challenges against the clinical translation of these important nanomedicines.

A Library of Custom PEG-Lipids reveals a Double-PEG-Lipid with Drastically Enhanced Paclitaxel Solubility and Human Cancer Cell Cytotoxicity when used in Fluid Micellar Nanoparticles

Paclitaxel (PTX) is one of the most widely utilized chemotherapeutics globally. However, the extremely poor water solubility of paclitaxel necessitates a mechanism of delivery within blood. Fluid lipid PTX nanocarriers (lipids in the chain-melted state) show promise as PTX delivery vectors, but remain limited by their solubility of PTX within the membrane. To improve pharmacokinetics, membrane surfaces are typically coated with polyethylene glycol (PEG). Recent work has demonstrated the generation of a population of micelles within fluid lipid formulations containing a 2kDa PEG-lipid at a 10 mol% ratio. Driven by the positive curvature of the PEG-lipid (i.e. area of head group > area of tails), micelle-containing formulations were found to exhibit significantly higher uptake in cancer cells, cytotoxicity, and in vivo antitumor efficacy compared to formulations containing solely liposomes. Here, we describe the custom synthesis of a library of high-curvature micelle-inducing PEG-lipids and examine the effects of PEG chain length, chain branching (single- or double-PEG-lipid), and cationic charge on PTX solubility and cytotoxicity. We examined PEG-lipids at standard (10 mol%) and high (100-x mol%, where x=PTX mol%) formulation ratios. Remarkably, all formulations containing the synthesized high-curvature PEG-lipids had improved PTX solubility over unPEGylated formulations and commercially available DOPE-5k. The highest PTX solubility was found within the 100-xPTX mol% PEG-lipid micellar formulations, with particles made from 2k2 (two PEG2k chains) encapsulating 13 mol% PTX for up to 24 h. The pancreatic cancer cell line PC3 exhibited higher sensitivity to formulations containing PEG-lipid at 100-xPTX mol%, the most potent of which being formulations made from 2k2 (IC50 = 14 nM). The work presented here suggests formulations employing high-curvature PEG-lipids, particularly the double-PEG-lipid 2k2, hold great potential as next-generation PTX delivery systems owing to their high PTX solubility, enhanced cell cytotoxicity, and ability for precision targeting by affixation of ligands to the PEG molecules.

An Overview of Cancer Biology, Pathophysiological Development and It's Treatment Modalities: Current Challenges of Cancer anti-Angiogenic Therapy

A number of conditions and factors can cause the transformation of normal cells in the body into malignant tissue by changing the normal functions of a wide range of regulatory, apoptotic, and signal transduction pathways. Despite the current deficiency in fully understanding the mechanism of cancer action accurately and clearly, numerous genes and proteins that are causally involved in the initiation, progression, and metastasis of cancer have been identified. But due to the lack of space and the abundance of details on this complex topic, we have emphasized here more recent advances in our understanding of the principles implied tumor cell transformation, development, invasion, angiogenesis, and metastasis. Inhibition of angiogenesis is a significant strategy for the treatment of various solid tumors, that essentially depend on cutting or at least limiting the supply of blood to micro-regions of tumors, leading to pan-hypoxia and pan-necrosis inside solid tumor tissues. Researchers have continued to enhance the efficiency of anti-angiogenic drugs over the past two decades, to identify their potential in the drug interaction, and to discover reasonable interpretations for possible resistance to treatment. In this review, we have discussed an overview of cancer history and recent methods use in cancer therapy, focusing on anti-angiogenic inhibitors targeting angiogenesis formation. Further, this review has explained the molecular mechanism of action of these anti-angiogenic inhibitors in various tumor types and their limitations use. In addition, we described the synergistic mechanisms of immunotherapy and anti-angiogenic therapy and summarizes current clinical trials of these combinations. Many phase III trials found that combining immunotherapy and anti-angiogenic therapy improved survival. Therefore, targeting the source supply of cancer cells to grow and spread with new anti-angiogenic agents in combination with different conventional therapy is a novel method to reduce cancer progression. The aim of this paper is to overview the varying concepts of cancer focusing on mechanisms involved in tumor angiogenesis and provide an overview of the recent trends in anti-angiogenic strategies for cancer therapy.

Targeted Nanocarrier-Based Drug Delivery Strategies for Improving the Therapeutic Efficacy of PARP Inhibitors against Ovarian Cancer

The current focus of ovarian cancer (OC) research is the improvement of treatment options through maximising drug effectiveness. OC remains the fifth leading cause of cancer-induced mortality in women worldwide. In recent years, nanotechnology has revolutionised drug delivery systems. Nanoparticles may be utilised as carriers in gene therapy or to overcome the problem of drug resistance in tumours by limiting the number of free drugs in circulation and thereby minimising undesired adverse effects. Cell surface receptors, such as human epidermal growth factor 2 (HER2), folic acid (FA) receptors, CD44 (also referred to as homing cell adhesion molecule, HCAM), and vascular endothelial growth factor (VEGF) are highly expressed in ovarian cancer cells. Generation of active targeting nanoparticles involves modification with ligands that recognise cell surface receptors and thereby promote internalisation by cancer cells. Several poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) are currently used for the treatment of high-grade serous ovarian carcinomas (HGSOC) or platinum-sensitive relapsed OC. However, PARP resistance and poor drug bioavailability are common challenges, highlighting the urgent need to develop novel, effective strategies for ovarian cancer treatment. This review evaluates the utility of nanoparticles in ovarian cancer therapy, with a specific focus on targeted approaches and the use of PARPi nanocarriers to optimise treatment outcomes.

Development and Characterization of Quercetin-Loaded Polymeric Liposomes with Gelatin-Poly(ethylene glycol)-Folic Acid Coating to Increase Their Long-Circulating and Anticancer Activity

Liposomes as drug-delivery systems have been researched and applied in multiple scientific reports and introduced as patented products with interesting therapeutic properties. Despite various advantages, this drug carrier faces major difficulties in its innate stability, cancer cell specificity, and control over the release of hydrophobic drugs, particularly quercetin, a naturally derived drug that carries many desirable characteristics for anticancer treatment. To improve the effectiveness of liposomes to deliver quercetin by tackling and mitigating the mentioned hurdles, we developed a strategy to establish the ability to passively target cancerous cells, as well as to increase the bioavailability of loaded drugs by incorporating poly(ethylene glycol), gelatin, and folic acid moieties to modify the liposomal system's surface. This research developed a chemically synthesized gelatin, poly(ethylene glycol), and folic acid as a single polymer to coat drug-loaded liposome systems. Liposomes were coated with gelatin-poly(ethylene glycol)-folic acid by electrostatic interaction, characterized by their size, morphology, ζ potential, drug loading efficiency, infrared structures, differential scanning calorimetry spectra, and drug-releasing profiles, and then evaluated for their cytotoxicity to MCF-7 breast cancer cells, as well as cellular uptake, analyzed by confocal imaging to further elaborate on the in vitro behavior of the coated liposome. The results indicated an unusual change in size with increased coating materials, followed by increased colloidal stability, ζ potential, and improved cytotoxicity to cancer cells, as shown by the cellular viability test with MCF-7. Cellular uptake also confirmed these results, providing data for the effects of biopolymer coating, while confirming that folic acid can increase the uptake of liposome by cancer cells. In consideration of such results, the modified gelatin-poly(ethylene glycol)-folic acid-coated liposome can be a potential system in delivering the assigned anticancer compound. This modified biopolymer showed excellent properties as a coating material and should be considered for further practical applications in the future.

Stimulus-Responsive Nanodelivery and Release Systems for Cancer Gene Therapy: Efficacy Improvement Strategies

Introduction of exogenous genes into target cells to overcome various tumor diseases caused by genetic defects or abnormalities and gene therapy, a new treatment method, provides a promising strategy for tumor treatment. Over the past decade, gene therapy has made exciting progress; however, it still faces the challenge of low nucleic acid delivery and release efficiencies. The emergence of nonviral vectors, primarily nanodelivery and release systems (NDRS), has resulted in a historic breakthrough in the application of gene therapy. NDRS, especially stimulus-responsive NDRS that can respond in a timely manner to changes in the internal and external microenvironment (eg, low pH, high concentration of glutathione/reactive oxygen species, overexpressed enzymes, temperature, light, ultrasound, and magnetic field), has shown excellent loading and release advantages in the precision and efficiency of tumor gene therapy and has been widely applied. The only disadvantage is that poor transfection efficiency limits the in-depth application of gene therapy in clinical practice, owing to the presence of biological barriers in the body. Therefore, this review first introduces the development history of gene therapy, the current obstacles faced by gene delivery, strategies to overcome these obstacles, and conventional vectors, and then focuses on the latest research progress in various stimulus-responsive NDRS for improving gene delivery efficiency. Finally, the future challenges and prospects that stimulus-responsive NDRS may face in clinical application and transformation are discussed to provide references for enhancing in-depth research on tumor gene therapy.

Lipid Nanocarrier-Based mRNA Therapy: Challenges and Promise for Clinical Transformation

Due to the outbreak of novel coronavirus pneumonia, messenger RNA (mRNA) technology has attracted heated attention. A specific, safe, and efficient mRNA delivery system is needed. Lipid nanocarriers have become attractive carriers for mRNA delivery due to their high delivery efficiency, few side effects, and easy modification to change their structures and functions. To achieve the desired biological effect, lipid nanocarriers must reach the designated location for effective drug delivery. Therefore, the effects of the composition of lipid nanocarriers on their key properties are briefly reviewed. In addition, the progress of smart drug delivery by changing the composition of lipid nanocarriers is summarized, and the importance of component design and structure is emphasized. Subsequently, this review summarizes the latest progress in lipid nanocarrier-based mRNA technology and provides corresponding strategies for its current challenges, putting forward valuable information for the future design of lipid nanocarriers and mRNA.

Permanently Charged Cationic Lipids-Evolution from Excipients to Therapeutic Lipids

Cationic lipids are crucial in medical and biotechnological applications including cellular transfection and gene delivery. Ionizable cationic lipids are critical components of the mRNA-based COVID vaccines while permanently charged cationic lipids have shown promise in cancer treatment. Despite significant research progress over the past few decades in designing improved, biocompatible cationic lipids, their transfection efficiency remains lower than that of viral vectors. Cationic lipids with additional functionalities like fusogenicity, stimuli-responsiveness, targeting capabilities, and therapeutic activity have been engineered to improve their performance. This review highlights the importance of molecular hybridization toward the design of biocompatible cationic lipids having fusogenic, stimuli-responsive, targeting, or therapeutic properties. This review mainly focuses on cationic lipids, having a permanent positive charge in the headgroup region, as these are typically employed to both increase cellular interactions and for improved loading, particularly for anionic nucleic acid-based therapeutics and vaccines. Structure-activity relationships between the lipid chemical structure (headgroup, spacer, hydrocarbon chain) and, to a lesser extent, the self-assembled nanostructure and the intrinsic biological activity of the multi-functional cationic lipids are described. Finally, the challenges involved in developing smart lipids without affecting their inherent capacity to self-assemble into structured nano-carriers are discussed.

Stealth Nanocarriers in Cancer Therapy: a Comprehensive Review of Design, Functionality, and Clinical Applications

Nanotechnology has significantly transformed cancer treatment by introducing innovative methods for delivering drugs effectively. This literature review provided an in-depth analysis of the role of nanocarriers in cancer therapy, with a particular focus on the critical concept of the 'stealth effect.' The stealth effect refers to the ability of nanocarriers to evade the immune system and overcome physiological barriers. The review investigated the design and composition of various nanocarriers, such as liposomes, micelles, and inorganic nanoparticles, highlighting the importance of surface modifications and functionalization. The complex interaction between the immune system, opsonization, phagocytosis, and the protein corona was examined to understand the stealth effect. The review carefully evaluated strategies to enhance the stealth effect, including surface coating with polymers, biomimetic camouflage, and targeting ligands. The in vivo behavior of stealth nanocarriers and their impact on pharmacokinetics, biodistribution, and toxicity were also systematically examined. Additionally, the review presented clinical applications, case studies of approved nanocarrier-based cancer therapies, and emerging formulations in clinical trials. Future directions and obstacles in the field, such as advancements in nanocarrier engineering, personalized nanomedicine, regulatory considerations, and ethical implications, were discussed in detail. The review concluded by summarizing key findings and emphasizing the transformative potential of stealth nanocarriers in revolutionizing cancer therapy. This review enhanced the comprehension of nanocarrier-based cancer therapies and their potential impact by providing insights into advanced studies, clinical applications, and regulatory considerations.

Surface-modified cationic liposomes with a matrix metalloproteinase-degradable polyethylene glycol derivative improved doxorubicin delivery in murine colon cancer

PEGylation is a commonly used approach to prolong the blood circulation time of cationic liposomes. However, PEGylation is associated with the "PEG dilemma", which hinders binding and uptake into tumor cells. The cleavable PEG products are a possible solution to this problem. In the current research, doxorubicin-loaded cationic liposomes (Dox-CLs) surface-conjugated with a matrix metalloproteinase-2 (MMP-2)-sensitive octapeptide linker-PEG derivative were prepared and compared to non-PEGylated and PEGylated CLs in terms of size, surface charge, drug encapsulation and release, uptake, in vivo pharmacokinetics, and anticancer efficacy. It was postulated that PEG deshielding in response to the overexpressed MMP-2 in the tumor microenvironment increases the interaction of protected CLs with cellular membranes and improves their uptake by tumor cells/vasculature. MMP2-responsive Dox-CLs had particle sizes of ∼115-140 nm, surface charges of ∼+25 mV, and encapsulation efficiencies of ∼85-95%. In vitro cytotoxicity assessments showed significantly enhanced uptake and cytotoxicity of PEG-cleavable CLs compared to their non-cleavable PEG-coated counterparts or Caelyx®. Also, the chick chorioallantoic membrane assay showed great antiangiogenesis ability of Dox-CLs leading to target and prevent tumor neovascularization. Besides, in vivo studies showed an effective therapeutic efficacy of PEG-cleavable Dox-CLs in murine colorectal cancer with negligible hematological and histopathological toxicity. Altogether, our results showed that MMP2-responsive Dox-CLs could be served as a promising approach to improve tumor drug delivery and uptake.

Cationic cycloamylose based nucleic acid nanocarriers

Nucleic acid delivery by viral and non-viral methods has been a cornerstone for the contemporary gene therapy aimed at correcting the defective genes, replacing of the missing genes, or downregulating the expression of anomalous genes is highly desirable for the management of various diseases. Ostensibly, it becomes paramount for the delivery vectors to intersect the biological barriers for accessing their destined site within the cellular environment. However, the lipophilic nature of biological membranes and their potential to limit the entry of large sized, charged, hydrophilic molecules thus presenting a sizeable challenge for the cellular integration of negatively charged nucleic acids. Furthermore, the susceptibility of nucleic acids towards the degrading enzymes (nucleases) in the lysosomes present in cytoplasm is another matter of concern for their cellular and nuclear delivery. Hence, there is a pressing need for the identification and development of cationic delivery systems which encapsulate the cargo nucleic acids where the charge facilitates their cellular entry by evading the membrane barriers, and the encapsulation shields them from the enzymatic attack in cytoplasm. Cycloamylose bearing a closed loop conformation presents a robust candidature in this regard owing to its remarkable encapsulating tendency towards nucleic acids including siRNA, CpG DNA, and siRNA. The presence of numerous hydroxyl groups on the cycloamylose periphery provides sites for its chemical modification for the introduction of cationic groups, including spermine, (3-Chloro-2 hydroxypropyl) trimethylammonium chloride (Q188), and diethyl aminoethane (DEAE). The resulting cationic cycloamylose possesses a remarkable transfection efficiency and provides stability to cargo oligonucleotides against endonucleases, in addition to modulating the undesirable side effects such as unwanted immune stimulation. Cycloamylose is known to interact with the cell membranes where they release certain membrane components such as phospholipids and cholesterol thereby resulting in membrane destabilization and permeabilization. Furthermore, cycloamylose derivatives also serve as formulation excipients for improving the efficiency of other gene delivery systems. This review delves into the various vector and non-vector-based gene delivery systems, their advantages, and limitations, eventually leading to the identification of cycloamylose as an ideal candidate for nucleic acid delivery. The synthesis of cationic cycloamylose is briefly discussed in each section followed by its application for specific delivery/transfection of a particular nucleic acid.

Intranasal Delivery of Carvedilol- and Quercetin-Encapsulated Cationic Nanoliposomes for Cardiovascular Targeting: Formulation and In Vitro and Ex Vivo Studies

Carvedilol (CVD), an adrenoreceptor blocker, is a hydrophobic Biopharmaceutics Classification System class II drug with poor oral bioavailability due to which frequent dosing is essential to attain pharmacological effects. Quercetin (QC), a polyphenolic compound, is a potent natural antioxidant, but its oral dosing is restricted due to poor aqueous solubility and low oral bioavailability. To overcome the common limitations of both drugs and to attain synergistic cardioprotective effects, we formulated CVD- and QC-encapsulated cationic nanoliposomes (NLPs) in situ gel (CVD/QC-L.O.F.) for intranasal administration. We designed CVD- and QC-loaded cationic nanoliposomal (NLPs) in situ gel (CVD/QC-L.O.F.) for intranasal administration. In vitro drug release studies of CVD/QC-L.O.F. (16.25%) exhibited 18.78 ± 0.57% of QC release and 91.38 ± 0.93% of CVD release for 120 h. Ex vivo nasal permeation studies of CVD/QC-L.O.F. demonstrated better permeation of QC (within 96 h), i.e., 75.09% compared to in vitro drug release, whereas CVD permeates within 48 h, indicating the better interaction between cationic NLPs and the negatively charged biological membrane. The developed nasal gel showed a sufficient mucoadhesive property, good spreadability, higher firmness, consistency, and cohesiveness, indicating suitability for membrane application and intranasal administration. CVD-NLPs, QC-NLPs, and CVD/QC-NLPs were evaluated for in vitro cytotoxicity, in vitro ROS-induced cell viability assessment, and a cellular uptake study using H9c2 rat cardiomyocytes. The highest in vitro cellular uptake of CVD/QC-cationic NLPs by H9c2 cells implies the benefit of QC loading within the CVD nanoliposomal carrier system and gives evidence for better interaction of NLPs carrying positive charges with the negatively charged biological cells. The in vitro H2O2-induced oxidative stress cell viability assessment of H9c2 cells established the intracellular antioxidant activity and cardioprotective effect of CVD/QC-cationic NLPs with low cytotoxicity. These findings suggest the potential of cationic NLPs as a suitable drug delivery carrier for CVD and QC combination for the intranasal route in the treatment of various cardiovascular diseases like hypertension, angina pectoris, etc. and for treating neurodegenerative disorders.

Novel Efficient Lipid-Based Delivery Systems Enable a Delayed Uptake and Sustained Expression of mRNA in Human Cells and Mouse Tissues

Over the past decade, mRNA-based therapy has displayed significant promise in a wide range of clinical applications. The most striking example of the leap in the development of mRNA technologies was the mass vaccination against COVID-19 during the pandemic. The emergence of large-scale technology and positive experience of mRNA immunization sparked the development of antiviral and anti-cancer mRNA vaccines as well as therapeutic mRNA agents for genetic and other diseases. To facilitate mRNA delivery, lipid nanoparticles (LNPs) have been successfully employed. However, the diverse use of mRNA therapeutic approaches requires the development of adaptable LNP delivery systems that can control the kinetics of mRNA uptake and expression in target cells. Here, we report effective mRNA delivery into cultured mammalian cells (HEK293T, HeLa, DC2.4) and living mouse muscle tissues by liposomes containing either 1,26-bis(cholest-5-en-3β-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride (2X3) or the newly applied 1,30-bis(cholest-5-en-3β-yloxycarbonylamino)-9,13,18,22-tetraaza-3,6,25,28-tetraoxatriacontane tetrahydrochloride (2X7) cationic lipids. Using end-point and real-time monitoring of Fluc mRNA expression, we showed that these LNPs exhibited an unusually delayed (of over 10 h in the case of the 2X7-based system) but had highly efficient and prolonged reporter activity in cells. Accordingly, both LNP formulations decorated with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE-PEG2000) provided efficient luciferase production in mice, peaking on day 3 after intramuscular injection. Notably, the bioluminescence was observed only at the site of injection in caudal thigh muscles, thereby demonstrating local expression of the model gene of interest. The developed mRNA delivery systems hold promise for prophylactic applications, where sustained synthesis of defensive proteins is required, and open doors to new possibilities in mRNA-based therapies.

Bis-arylidene oxindoles for colorectal cancer nanotherapy

Oxindoles are potent anti-cancer agents and are also used against microbial and fungal infections and for treating neurodegenerative diseases. These oxindoles are earlier established as estrogen receptor (ER)-targeted agents for killing ER (+) cancer cells. Our previously developed bis-arylidene oxindole, Oxifen (OXF) exhibits effective targeting towards ER (+) cancer cells which has a structural resemblance with tamoxifen. Herein, we have designed and synthesized few structural analogues of OXF such as BPYOX, ACPOX and ACPOXF to examine its cytotoxicity in different cancer as well as non-cancer cell lines and its potential to form self- aggregates in aqueous solution. Among these series of molecules, ACPOXF showed maximum toxicity in colorectal cancer cell line which are ER (-) but it also kills non-cancer cell line HEK-293, thereby reducing its cancer cell selectivity. Incidentally, ACPOXF exhibits self-aggregation, without the help of a co-lipid with nanometric size in aqueous solution. ACPOXF self-aggregate was co-formulated with glucocorticoid receptor (GR) synthetic ligand, dexamethasone (Dex) (called, ACPOXF-Dex aggregate) which could selectively kill ER (-) colorectal cancer cells and also could increase survivability of colon-tumour bearing mice. ACPOXF-Dex induced ROS up-regulation followed by apoptosis through expression of caspase-3. Further, we observed upregulation of antiproliferative factor, p53 and epithelial-to-mesenchymal (EMT) reversal marker E-cadherin in tumour mass. In conclusion, a typical structural modification in ER-targeting Oxifen moiety resulted in its self-aggregation that enabled it to carry a GR-ligand, thus broadening its selective antitumor property especially as colon cancer therapeutics.

Engineering aspects of lipid-based delivery systems: In vivo gene delivery, safety criteria, and translation strategies

Defects in the genome cause genetic diseases and can be treated with gene therapy. Due to the limitations encountered in gene delivery, lipid-based supramolecular colloidal materials have emerged as promising gene carrier systems. In their non-functionalized form, lipid nanoparticles often demonstrate lower transgene expression efficiency, leading to suboptimal therapeutic outcomes, specifically through reduced percentages of cells expressing the transgene. Due to chemically active substituents, the engineering of delivery systems for genetic drugs with specific chemical ligands steps forward as an innovative strategy to tackle the drawbacks and enhance their therapeutic efficacy. Despite intense investigations into functionalization strategies, the clinical outcome of such therapies still needs to be improved. Here, we highlight and comprehensively review engineering aspects for functionalizing lipid-based delivery systems and their therapeutic efficacy for developing novel genetic cargoes to provide a full snapshot of the translation from the bench to the clinics. We outline existing challenges in the delivery and internalization processes and narrate recent advances in the functionalization of lipid-based delivery systems for nucleic acids to enhance their therapeutic efficacy and safety. Moreover, we address clinical trials using these vectors to expand their clinical use and principal safety concerns.

Physiological Barriers and Strategies of Lipid-Based Nanoparticles for Nucleic Acid Drug Delivery

Lipid-based nanoparticles (LBNPs) are currently the most promising vehicles for nucleic acid drug (NAD) delivery. Although their clinical applications have achieved success, the NAD delivery efficiency and safety are still unsatisfactory, which are, to a large extent, due to the existence of multi-level physiological barriers in vivo. It is important to elucidate the interactions between these barriers and LBNPs, which will guide more rational design of efficient NAD vehicles with low adverse effects and facilitate broader applications of nucleic acid therapeutics. This review describes the obstacles and challenges of biological barriers to NAD delivery at systemic, organ, sub-organ, cellular, and subcellular levels. The strategies to overcome these barriers are comprehensively reviewed, mainly including physically/chemically engineering LBNPs and directly modifying physiological barriers by auxiliary treatments. Then the potentials and challenges for successful translation of these preclinical studies into the clinic are discussed. In the end, a forward look at the strategies on manipulating protein corona (PC) is addressed, which may pull off the trick of overcoming those physiological barriers and significantly improve the efficacy and safety of LBNP-based NADs delivery.

Effects of Anionic Liposome Delivery of All-Trans-Retinoic Acid on Neuroblastoma Cell Differentiation

All-trans-retinoic acid (ATRA) has long been known to affect cell growth and differentiation. To improve ATRA's therapeutic efficacy and pharmacodynamics, several delivery systems have been used. In this study, free ATRA and anionic-liposome-encapsulated ATRA were compared for their effects on SK-N-SH human neuroblastoma cell growth and differentiation. Anionic liposomes made of L-α-phosphatidylcholine (PC) and L-α-phosphatidic acid (PA), empty (PC-PA) and loaded with ATRA (PC-PA-ATRA), were characterized by dynamic light scattering (DLS) and electrophoretic mobility measurements, and drug entrapment efficiency (EE%) was measured to evaluate the applicability of the new colloidal formulation. The results of brightfield microscopy and cell growth curves indicated that ATRA, whether free or encapsulated, reduced growth and induced differentiation, resulting in SK-N-SH cells changing from epithelioid to neuronal-like morphologies, and producing a significant increase in neurite growth. To further characterize the neuro-differentiation of SK-N-SH cells, the expression of βIII-Tubulin and synaptophysin and mitochondria localization were analyzed via immunofluorescence. Increased expression of neuronal markers and a peculiar localization of mitochondria in the neuritic extensions were apparent both in ATRA- and PC-PA-ATRA-differentiated cells. As a whole, our results strongly indicate that ATRA treatment, by any means, can induce the differentiation of parent SK-N-SH, and they highlight that its encapsulation in anionic liposomes increases its differentiation ability in terms of the percentage of neurite-bearing cells. Interestingly, our data also suggest an unexpected differentiation capability of anionic liposomes per se. This work highlights the importance of developing and carefully testing novel delivery nanocarriers, which are a necessary first "step" in the development of new therapeutic settings.

Impact of Lipid Composition on Vesicle Protein Adsorption: A BSA Case Study

Investigating the interaction between liposomes and proteins is of paramount importance in the development of liposomal formulations with real potential for bench-to-bedside transfer. Upon entering the body, proteins are immediately adsorbed on the liposomal surface, changing the nanovehicles' biological identity, which has a significant impact on their biodistribution and pharmacokinetics and ultimately on their therapeutic effect. Albumin is the most abundant plasma protein and thus usually adsorbs immediately on the liposomal surface. We herein report a comprehensive investigation on the adsorption of model protein bovine serum albumin (BSA) onto liposomal vesicles containing the zwitterionic lipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), in combination with either cholesterol (CHOL) or the cationic lipid 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP). While many studies regarding protein adsorption on the surface of liposomes with different compositions have been performed, to the best of our knowledge, the differential responses of CHOL and DOTAP upon albumin adsorption on vesicles have not yet been investigated. UV-vis spectroscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed a strong influence of the phospholipid membrane composition on protein adsorption. Hence, it was found that DOTAP-containing vesicles adsorb proteins more robustly but also aggregate in the presence of BSA, as confirmed by DLS and TEM. Separation of liposome-protein complexes from unadsorbed proteins performed by means of centrifugation and size exclusion chromatography (SEC) was also investigated. Our results show that neither method can be regarded as a golden experimental setup to study the protein corona of liposomes. Yet, SEC proved to be more successful in the separation of unbound proteins, although the amount of lipid loss upon liposome elution was higher than expected. In addition, coarse-grained molecular dynamics simulations were employed to ascertain key membrane parameters, such as the membrane thickness and area per lipid. Overall, this study highlights the importance of surface charge and membrane fluidity in influencing the extent of protein adsorption. We hope that our investigation will be a valuable contribution to better understanding protein-vesicle interactions for improved nanocarrier design.

Polymer-lipid hybrid nanomedicines to deliver siRNA in and against glioblastoma cells

Small interfering RNA (siRNA) holds great potential to treat many difficult-to-treat diseases, but its delivery remains the central challenge. This study aimed at investigating the suitability of polymer-lipid hybrid nanomedicines (HNMeds) as novel siRNA delivery platforms for locoregional therapy of glioblastoma. Two HNMed formulations were developed from poly(lactic-co-glycolic acid) polymer and a cationic lipid: 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) or 3ß-[N-(N',N'-dimethylaminoethane)-carbamoyl]cholesterol (DC-Chol). After characterization of the HNMeds, a model siRNA was complexed onto their surface to form HNMed/siRNA complexes. The physicochemical properties and siRNA binding ability of complexes were assessed over a range of nitrogen-to-phosphate (N/P) ratios to optimize the formulations. At the optimal N/P ratio of 10, complexes effectively bound siRNA and improved its protection from enzymatic degradation. Using the NIH3T3 mouse fibroblast cell line, DOTAP-based HNMeds were shown to possess higher cytocompatibility in vitro over the DC-Chol-based ones. As proof-of-concept, uptake and bioefficacy of formulations were also assessed in vitro on U87MG human glioblastoma cell line expressing luciferase gene. Complexes were able to deliver anti-luciferase siRNA and induce a remarkable suppression of gene expression. Noteworthy, the effect of DOTAP-based formulation was not only about three-times higher than DC-Chol-based one, but also comparable to lipofectamine model transfection reagent. These findings set the basis to exploit this nanosystem for silencing relevant GB-related genes in further in vitro and in vivo studies.

Nanocarrier-based gene delivery for immune cell engineering

Clinical advances in genetically modified immune cell therapies, such as chimeric antigen receptor T cell therapies, have raised hope for cancer treatment. The majority of these biotechnologies are based on viral methods for ex vivo genetic modification of the immune cells, while the non-viral methods are still in the developmental phase. Nanocarriers have been emerging as materials of choice for gene delivery to immune cells. This is due to their versatile physicochemical properties such as large surface area and size that can be optimized to overcome several practical barriers to successful gene delivery. The in vivo nanocarrier-based gene delivery can revolutionize cell-based cancer immunotherapies by replacing the current expensive autologous cell manufacturing with an off-the-shelf biomaterial-based platform. The aim of this research is to review current advances and strategies to overcome the challenges in nanoparticle-based gene delivery and their impact on the efficiency, safety, and specificity of the process. The main focus is on polymeric and lipid-based nanocarriers, and their recent preclinical applications for cancer immunotherapy.

Recent trends and advances in novel formulations as an armament in Bcl-2/Bax targeted breast cancer

Breast cancer (BC) remains a significant health burden worldwide, necessitating the development of innovative therapeutic strategies. The B-cell lymphoma 2 (Bcl-2) family proteins, Bcl-2 and Bax, play a crucial role in regulating apoptosis and thus are promising targets for BC therapy. We focus on the recent advancements in novel formulations that specifically target Bcl-2/Bax pathway to combat BC. It provides an overview on biological functions of Bcl-2/Bax in apoptosis regulation, emphasizing their significance in pathogenesis and progression of the disease while covering the numerous therapeutic approaches aimed at modulating the Bcl-2/Bax pathway, including small-molecule inhibitors, peptides, gene-based therapies and other repurposed drugs harboured onto cutting-edge technologies and nanocarrier systems employed to enhance the targeted delivery of Bcl-2/Bax inhibitors tumor cells. These advanced formulations aim to improve therapeutic efficacy, minimize off-target effects, and overcome drug resistance, offering promising prospects in its treatment. In conclusion, it illuminates the diverse and evolving landscape of novel formulations as an essential armament in targeting these proteins while bridging and unravelling the obscurity of Bcl-2/Bax pathway-targeted drug delivery systems which are presently in their nascent stages of exploration for BC therapy which can benefit researchers, clinicians, and pharmaceutical scientists.

Filamentous-Actin-Mimicking Nanoplatform for Enhanced Cytosolic Protein Delivery

Despite the potential of protein therapeutics, the cytosolic delivery of proteins with high efficiency and bioactivity remains a significant challenge owing to exocytosis and lysosomal degradation after endocytosis. Therefore, it is important to develop a safe and efficient strategy to bypass endocytosis. Inspired by the extraordinary capability of filamentous-actin (F-actin) to promote cell membrane fusion, a cyanine dye assembly-containing nanoplatform mimicking the structure of natural F-actin is developed. The nanoplatform exhibits fast membrane fusion to cell membrane mimics and thus enters live cells through membrane fusion and bypasses endocytosis. Moreover, it is found to efficiently deliver protein cargos into live cells and quickly release them into the cytosol, leading to high protein cargo transfection efficiency and bioactivity. The nanoplatform also results in the superior inhibition of tumor cells when loaded with anti-tumor proteins. These results demonstrate that this fusogenic nanoplatform can be valuable for cytosolic protein delivery and tumor treatment.

Redox-Responsive Polymeric Nanoparticle for Nucleic Acid Delivery and Cancer Therapy: Progress, Opportunities, and Challenges

Cancer development and progression of cancer are closely associated with the activation of oncogenes and loss of tumor suppressor genes. Nucleic acid drugs (e.g., siRNA, mRNA, and DNA) are widely used for cancer therapy due to their specific ability to regulate the expression of any cancer-associated genes. However, nucleic acid drugs are negatively charged biomacromolecules that are susceptible to serum nucleases and cannot cross cell membrane. Therefore, specific delivery tools are required to facilitate the intracellular delivery of nucleic acid drugs. In the past few decades, a variety of nanoparticles (NPs) are designed and developed for nucleic acid delivery and cancer therapy. In particular, the polymeric NPs in response to the abnormal redox status in cancer cells have garnered much more attention as their potential in redox-triggered nanostructure dissociation and rapid intracellular release of nucleic acid drugs. In this review, the important genes or signaling pathways regulating the abnormal redox status in cancer cells are briefly introduced and the recent development of redox-responsive NPs for nucleic acid delivery and cancer therapy is systemically summarized. The future development of NPs-mediated nucleic acid delivery and their challenges in clinical translation are also discussed.

In vivo biodistribution and ototoxicity assessment of cationic liposomal-ceftriaxone via noninvasive trans-tympanic delivery in chinchilla models: Implications for otitis media therapy

OBJECTIVES

We report the in vivo biodistribution and ototoxicity of cationic liposomal-ceftriaxone (CFX) delivered via ear drop formulation in adult chinchilla.

METHODS

CFX was encapsulated in liposomes with size of ∼100 nm and surface charge of +20 mV. 100 μl liposomes or free drug was applied twice daily in both external ear canals of adult chinchillas for either 3 or 10 days. Study groups included free ceftriaxone (CFX, Day 3: n = 4, Day 10: n = 8), liposomal ceftriaxone (CFX-Lipo, Day 3: n = 4, Day 10: n = 8), and a systemic control group (Day 3: n = 4, Day 10: n = 4). Ceftriaxone delivery to the middle ear and systemic circulation was quantified by HPLC assays. Liposome transport was visualized via confocal microscopy. Auditory brainstem response (ABR) tests and cochlear histology were used to assess ototoxicity.

RESULTS

Liposomal ceftriaxone (CFX-Lipo) displayed a ∼658-fold increase in drug delivery efficiency in the middle ear relative to the free CFX (8.548 ± 0.4638% vs. 0.013 ± 0.0009%, %Injected dose, Mean ± SEM). CFX measured in blood serum (48.2 ± 7.78 ng/ml) following CFX-Lipo treatment in ear was 41-fold lower compared to systemic free-CFX treatment (1990.7 ± 617.34 ng/ml). ABR tests and histological analysis indicated no ototoxicity due to the treatment.

CONCLUSION

Cationic liposomal encapsulation results in potent drug delivery across the tympanic membrane to the middle ear with minimal systemic exposure and no ototoxicity.

Exosomes: Membrane-associated proteins, challenges and perspectives

Membrane proteins determine the precise function of each membrane and, therefore, the function of each cell type. These proteins essential roles in cell physiology, participating in the maintenance of the cell metabolism, its homeostasis or promoting proper cell growth. Membrane proteins, as has long been described, are located both in the plasma membrane and in complex subcellular structures. However, they can also be released into the extracellular environment associated with extracellular vesicles (EVs). To date, most of the research have been focused on understanding the role of exosomal RNA in several processes. Recently, there has been increasing interest in studying the function of exosome membrane proteins for exosome-based therapy, but not much research has been done yet on the function of exosome membrane proteins. One of the major limitations of studying exosome membrane proteins and their application to translational research of exosome-based therapeutics is the low yield of exosome isolation. Here, we have introduced a new perspective on exosome membrane protein research by reviewing studies showing the important role of exosome membrane proteins in exosome-based therapies. Furthermore, we have proposed a new strategy to boost the yield of exosome isolation: hybridization of liposomes with exosome-derived membrane. Liposomes have already been reported to affect the cell excitation to increase exosome production in tumor cells. Therefore, increasing cellular uptake of these liposomes would enhance exosome release by increasing cellular excitation. This new perspective could be a breakthrough in exosome-based therapeutic research.

Recent advances and clinical translation of liposomal delivery systems in cancer therapy

The limitations of conventional cancer treatment are driving the emergence and development of nanomedicines. Research in liposomal nanomedicine for cancer therapy is rapidly increasing, opening up new horizons for cancer treatment. Liposomal nanomedicine, which focuses on targeted drug delivery to improve the therapeutic effect of cancer while reducing damage to normal tissues and cells, has great potential in the field of cancer therapy. This review aims to clarify the advantages of liposomal delivery systems in cancer therapy. We describe the recent understanding of spatiotemporal fate of liposomes in the organism after different routes of drug administration. Meanwhile, various types of liposome-based drug delivery systems that exert their respective advantages in cancer therapy while reducing side effects were discussed. Moreover, the combination of liposomal agents with other therapies (such as photodynamic therapy and photothermal therapy) has demonstrated enhanced tumor-targeting efficiency and therapeutic efficacy. Finally, the opportunities and challenges faced by the field of liposome nanoformulations for entering the clinical treatment of cancer are highlighted.

Evaluation of salivary transferrin in patients with oral squamous cell carcinoma

OBJECTIVES

About 94% of oral cancers are squamous cell carcinomas (OSCCs). Its occurrence is age-related due to some factors. Salivary biomarkers have good susceptibility to OSCC's early diagnosis. Moreover, since the clinical diagnosis of advanced stages of OSCC is feasible, its prognosis is very poor.

MATERIAL AND METHODS

According to inclusion and exclusion criteria, 40 OSCC patients and 40 healthy people were selected, and 5 mL of saliva were prepared from each person. The quantity of saline transferrin was computed. After that, the data were analyzed.

RESULTS

Our study results demonstrated that the mean and standard deviation of the salivary transferrin in the control group were 1.234 mL and 0.374, respectively, and in the case group, it was equal to 2.512 mL for the mean and 0.463 for the standard deviation. There was a statistically substantial difference between the mean of the salivary transferrin variable in the two study groups.

CONCLUSION

In conclusion, the mean concentration of salivary transferrin in the case group was higher than in the control group.

Nebulised delivery of RNA formulations to the lungs: From aerosol to cytosol

In the past decade RNA-based therapies such as small interfering RNA (siRNA) and messenger RNA (mRNA) have emerged as new and ground-breaking therapeutic agents for the treatment and prevention of many conditions from viral infection to cancer. Most clinically approved RNA therapies are parenterally administered which impacts patient compliance and adds to healthcare costs. Pulmonary administration via inhalation is a non-invasive means to deliver RNA and offers an attractive alternative to injection. Nebulisation is a particularly appealing method due to the capacity to deliver large RNA doses during tidal breathing. In this review, we discuss the unique physiological barriers presented by the lung to efficient nebulised RNA delivery and approaches adopted to circumvent this problem. Additionally, the different types of nebulisers are evaluated from the perspective of their suitability for RNA delivery. Furthermore, we discuss recent preclinical studies involving nebulisation of RNA and analysis in in vitro and in vivo settings. Several studies have also demonstrated the importance of an effective delivery vector in RNA nebulisation therefore we assess the variety of lipid, polymeric and hybrid-based delivery systems utilised to date. We also consider the outlook for nebulised RNA medicinal products and the hurdles which must be overcome for successful clinical translation. In summary, nebulised RNA delivery has demonstrated promising potential for the treatment of several lung-related conditions such as asthma, COPD and cystic fibrosis, to which the mode of delivery is of crucial importance for clinical success.

Novel Lipid Nanoparticles Stable and Efficient for mRNA Transfection to Antigen-Presenting Cells

mRNA vaccines have emerged as a pivotal tool in combating COVID-19, offering an advanced approach to immunization. A key challenge with these vaccines is their need for extremely-low-temperature storage, which affects their stability and shelf life. Our research addresses this issue by enhancing the stability of mRNA vaccines through a novel cationic lipid, O,O'-dimyristyl-N-lysyl aspartate (DMKD). DMKD effectively binds with mRNA, improving vaccine stability. We also integrated phosphatidylserine (PS) into the formulation to boost immune response by promoting the uptake of these nanoparticles by immune cells. Our findings reveal that DMKD-PS nanoparticles maintain structural integrity under long-term refrigeration and effectively protect mRNA. When tested, these nanoparticles containing green fluorescent protein (GFP) mRNA outperformed other commercial lipid nanoparticles in protein expression, both in immune cells (RAW 264.7 mouse macrophage) and non-immune cells (CT26 mouse colorectal carcinoma cells). Importantly, in vivo studies show that DMKD-PS nanoparticles are safely eliminated from the body within 48 h. The results suggest that DMKD-PS nanoparticles present a promising alternative for mRNA vaccine delivery, enhancing both the stability and effectiveness of these vaccines.