Cell-Penetrating Peptide-Based Delivery of Macromolecular Drugs: Development, Strategies, and Progress

Site-Specific Chemical Modulation of a Flexible Azaproline Transporter to Enhance Epirubicin Accumulation in Drug-Resistant Human Glioblastoma Cells and Blood-Brain Barrier Penetration in Adult Zebrafish

Cell-penetrating peptides (CPPs) have emerged as nonviral biological carriers for the delivery of macromolecular therapeutics into cells. Despite their lower immunogenicity and cellular toxicity, CPPs often lack target specificity and proteolytic stability. Various modified CPPs have been reported to improve such selective targeting and pharmacokinetic properties in vivo. On this frontier, we have previously reported the synthesis and in vitro activity of a protease-stable non-natural δ-azaproline (δ-azp) containing CPP, named Flexible Azaproline Transporter-1 (FAT-1). In this study, we report the chemical synthesis of three modified FAT analogs (FAT-2, FAT-3, and FAT-4) and compare their biological efficacy in vitro. These analogs were designed by incorporating a β-alanine spacer between the two adjacent azaproline monomers, with structural variations (branched or linear) and terminal δ-N functionalization. Comparative biological efficacy studies demonstrated that FAT-2 exhibited the highest potency among the series, with enhanced cellular uptake and efficient endosomal escape in CHO cells. For the functional evaluation of FAT-2, the scaffold was conjugated to the antineoplastic drug, Epirubicin. The conjugate (Epi-FAT2) showed efficient induction of apoptosis in drug-resistant human glioblastoma (LN-229) cells, inhibited cell migration, and reduced ABCG2/P-glycoprotein-mediated drug efflux. The intraperitoneal (IP) administration of Epi-FAT2 in Wild Indian Karyotype (WIK) adult zebrafish revealed its superior blood-brain barrier (BBB) penetration capability with greater/diverse tissue-dependent accumulation. The promising results of FAT-2 in both in vitro and in vivo studies highlight its potential for the delivery of CNS therapeutics and exemplify the importance of suitable scaffold modification in CPPs for future studies.

AI-driven innovations in smart multifunctional nanocarriers for drug and gene delivery: A mini-review

The convergence of artificial intelligence (AI) and nanomedicine has revolutionized the design of smart multifunctional nanocarriers (SMNs) for drug and gene delivery, offering unprecedented precision, efficiency, and personalization in therapeutic applications. AI-driven approaches enhance the development of these nanocarriers by accelerating their design, optimizing drug loading and release kinetics, improving biocompatibility, and predicting interactions with biological barriers. This review explores the transformative role of AI in the fabrication and functionalization of SMNs, emphasizing its impact on overcoming challenges in targeted drug delivery, controlled release, and theranostics. We discuss the integration of AI with advanced nanomaterials-such as polymeric, lipidic, and inorganic nanoparticles-highlighting their potential in oncology and hematology. Furthermore, we examine recent clinical and preclinical case studies demonstrating AI-assisted nanocarrier development for personalized medicine. The synergy between AI and nanotechnology paves the way for next-generation precision therapeutics, addressing critical limitations in traditional drug delivery systems. However, data standardization, regulatory compliance, and translational scalability challenges remain. This review underscores the need for interdisciplinary collaboration to unlock AI's potential in nanomedicine fully, ultimately advancing the clinical application of SMNs for more effective and safer patient care.

Differential insertion of arginine in saturated and unsaturated lipid vesicles

In this work, the effects of L- Arginine (L-Arg) insertion on saturated and unsaturated lipid membranes were assessed by fluorescence spectroscopy, dynamic light scattering (DLS) and monolayer measurements. The studied systems were composed by DPPC, 16:0 DietherPC, 16:1 Δ9-CisPC, DPPC:Chol, 16:1 Δ9-CisPC:Chol, and 16:1 Δ9-CisPC:DPPC in the presence of increasing concentrations of L-Arg. The information obtained using fluorescence spectral Laurdan properties indicates that L- Arg produces a decrease in the polarizability of saturated lipids congruent with the increase in vesicle size and area per lipid. However, in unsaturated lipids, the polarizability increases without significant changes in size and area per lipid denoting a different mechanism of insertion. The two opposite effects can be modulated by the saturated and unsaturated ratio and are independent of carbonyl groups. This modulation is damped by cholesterol. The differences in the L-Arg insertion can be explained considering that in the presence of the double bonds, L-Arg decreases the organized water in the lipid matrix without expanding the bilayer. Instead, in saturated lipid membranes, L-Arg inserts into the acyl chains dragging water and expanding the membrane area.

Prodrug Approach as a Strategy to Enhance Drug Permeability

Absorption and permeability are critical physicochemical parameters that must be balanced to achieve optimal drug uptake. These key factors are closely linked to the maximum absorbable dose required to provide appropriate plasma levels of drugs. Among the various strategies employed to enhance drug solubility and permeability, prodrug design stands out as a highly effective and versatile approach for improving physicochemical properties and enabling the optimization of biopharmaceutical and pharmacokinetic parameters while mitigating adverse effects. Prodrugs are compounds with reduced or no activity that, through bio-reversible chemical or enzymatic processes, release an active parental drug. The application of this technology has led to significant advancements in drug optimization during the design phase, and it offers broad potential for further development. Notably, approximately 13% of the drugs approved by the U.S. Food and Drug Administration (FDA) between 2012 and 2022 were prodrugs. In this review article, we will explore the application of prodrug strategies to enhance permeability, describing examples of market drugs. We also describe the use of the prodrug approach to optimize PROteolysis TArgeting Chimeras (PROTACs) permeability by using conjugation technologies. We will highlight some new technologies in prodrugs to enrich permeability properties, contributing to developing new effective and safe prodrugs.

Strategies and challenges of cytosolic delivery of proteins

The cytosolic delivery of therapeutic proteins represents a promising strategy for addressing diseases caused by protein dysfunction. Despite significant advances, efficient delivery remains challenging due to barriers such as cell membrane impermeability, endosomal sequestration and protein instability. This review summarises recent progress in protein delivery systems, including physical, chemical and biological approaches, with a particular focus on strategies that enhance endosomal escape and targeting specificity. We further discuss the clinical translatability of these approaches and propose future directions for improving delivery efficiency and safety, ultimately unlocking the therapeutic potential of intracellular proteins.

Advances and prospects of cell-penetrating peptides in tumor immunotherapy

Cell-penetrating peptides (CPPs) have been shown to have superior material transport ability because poor infiltration of activated lymphocytes into tumors is one of the crucial factors limiting the therapeutic effect of tumor immunotherapy. Numerous studies have investigated the potential application of CPPs in tumor immunotherapy. This review delves into the crucial role that CPPs play in enhancing tumor immunotherapy, emphasizing their impact on various immunotherapy strategies, such as cytokine therapy, adoptive cell therapy, cancer vaccines, and immune checkpoint inhibitors. We also discuss the practical application challenges associated with enhancing the efficiency of CPPs in terms of their stability and targeting ability. In conclusion, the combination of CPPs with tumor immunotherapy is a promising strategy that has potential for precision administration and requires further research for optimal implementation.

Improving the use of CRISPR/Cas9 gene editing machinery as a cancer therapeutic tool with the help of nanomedicine

CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-associated protein 9) has revolutionized gene editing tools and paved the way for innovations in medical research for disease diagnosis and treatment. However, better specificity and efficient delivery of this gene machinery make it challenging to successfully edit genes for treating various diseases. This is mainly due to cellular barriers, instability in biological environments, and various off-target effects that prohibit safe and efficient delivery under in vivo conditions. This review examines several delivery modes [plasmid, mRNA, RNP (ribonucleoprotein)] and methods for the CRISPR-Cas9 system delivery, focusing on its potential applications in cancer therapy. Biocompatibility and cytotoxicity are crucial factors determining their safe and effective use. Various nanomaterials have been reviewed for their biocompatibility, limitations, and challenges in treating cancer. Among the reviewed nanoparticles, lipid nanoparticles (LNPs) stand out for their biocompatibility due to their biomimetic lipid bilayer that effectively delivers CRISPR/Cas9 cargoes while reducing toxicity. We discuss challenges in in vivo delivery and associated findings such as encapsulation, target delivery, controlled release, and endosomal escape. Future directions involve addressing limitations and adapting CRISPR-Cas9 for clinical trials, ensuring its safe and effective use.

Macromolecular Function Emerging from Intramolecular Peptide Stapling of Synthetic Polymers

Protein function results from the precise folding of polypeptides into bespoke architectures. Taking inspiration from nature, the field of single-chain nanoparticles (SCNPs), intramolecularly crosslinked synthetic polymers, emerged. In contrast to nature, the function of SCNPs is generally defined by the parent polymer or the applied crosslinker, rather than by the crosslinking process itself. This work explores the cyanopyridine-aminothiol click reaction to crosslink peptide-decorated polymers intra-macromolecularly to endow the resulting SCNPs with emerging functionality, resulting from the conversion of N-terminal cysteine units into pyridine-thiazolines. Dimethylacrylamide based polymers with different cysteine-terminated amino acid sequences tethered to their sidechains are investigated (P1 (C), P2 (GDHC), P3 (GDSC)) and intramolecularly crosslinked into SCNPs. Since the deprotection of the parent polymers yields disulfide-based SCNPs, a direct comparison between disulfide and pyridine-thiazolines crosslinked SCNPs is possible. This comparison revealed two emerging properties of the pyridine-thiazoline crosslinked SCNPs: 1) The formation of pyridine-thiazolines gave rise to metal binding sites within the SCNP, which complexed iron. 2) Depending on the peptide sequence in the precursor polymer, the hydrolytic activity of the peptide sequences is either increased (GDHC) or decreased (GDSC) upon pyridine-thiazoline formation compared to identical SCNPs based on disulfide crosslinks.

Cell-Penetrating Peptides in infection and immunization

Bacteria and viruses pose significant threats to human health, as drug molecules and therapeutic agents are often hindered by cell membranes and tissue barriers from reaching intracellular targets. Cell-penetrating peptides (CPPs), composed of 5-30 amino acids, function as molecular shuttles that facilitate the translocation of therapeutic agents across biological barriers. Despite their therapeutic potential, CPPs exhibit limitations, such as insufficient cell specificity, low in vivo stability, reduced delivery efficiency, and limited tolerance under serum conditions. However, intelligent design and chemical modifications can enhance their cell penetration, stability, and selectivity. These advancements could significantly improve CPP-based drug delivery strategies, facilitating both infection treatment and immunization against bacterial and viral diseases. This review provides an overview of the applications of CPPs in various infections and immune diseases, summarizing their mechanisms and the challenges encountered during their application.

Feature Collection in Peptide Therapeutics: Current Applications and Future Directions

The use of peptides in medicine began long ago with peptidic hormones [...].

A high hydrophobic moment arginine-rich peptide screened by a machine learning algorithm enhanced ADC antitumor activity

Cell-penetrating peptides (CPPs) with better biomolecule delivery properties will expand their clinical applications. Using the MLCPP2.0 machine algorithm, we screened multiple candidate sequences with potential cellular uptake ability from the nuclear localization signal/nuclear export signal database and verified them through cell-penetrating fluorescent tracing experiments. A peptide (NCR) derived from the Rev protein of the caprine arthritis-encephalitis virus exhibited efficient cell-penetrating activity, delivering over four times more EGFP than the classical CPP TAT, allowing it to accumulate in lysosomes. Structural and property analysis revealed that a high hydrophobic moment and an appropriate hydrophobic region contribute to the high delivery activity of NCR. Trastuzumab emtansine (T-DM1), a HER2-targeted antibody-drug conjugate, could improve its anti-tumor activity by enhancing targeted delivery efficiency and increasing lysosomal drug delivery. This study designed a new NCR vector to non-covalently bind T-DM1 by fusing domain Z, which can specifically bind to the Fc region of immunoglobulin G and effectively deliver T-DM1 to lysosomes. MTT results showed that the domain Z-NCR vector significantly enhanced the cytotoxicity of T-DM1 against HER2-positive tumor cells while maintaining drug specificity. Our results make a useful attempt to explore the potential application of CPP as a lysosome-targeted delivery tool.

Cell-penetrating peptides for sustainable agriculture

Cell-penetrating peptides (CPPs) are short (typically 5-30 amino acids), cationic, amphipathic, or hydrophobic peptides that facilitate the cellular uptake of diverse cargo molecules by eukaryotic cells via direct translocation or endocytosis across the plasma membrane. CPPs can deliver a variety of bioactive cargos, including proteins, peptides, nucleic acids, and small molecules into the cell. Once inside, the delivered cargo may function in the cytosol, nucleus, or other subcellular compartments. Numerous CPPs have been used for studies and drug delivery in mammalian systems. Although CPPs have many potential uses in plant research and agriculture, the application of CPPs in plants remains limited. Here we review the structures and mechanisms of CPPs and highlight their potential applications for sustainable agriculture.

Tumor microenvironment-responsive cell-penetrating peptides: Design principle and precision delivery

Cell-penetrating peptides (CPPs) are promising vehicles for intracellular delivery of different cargoes. Although various CPPs are designed for targeted delivery of nanomedicines and anticancer drugs, their clinical approval is hampered by a lack of selectivity. In recent years, new approaches have been explored to address this drawback, and distinct strategies for tumor microenvironment (TME)-responsive activation have been developed. In this review, we first introduce the cellular uptake mechanisms of CPPs. We next extensively discuss the design principles and precision delivery of TME-responsive CPPs. Nine kinds of single stimulus-responsive CPPs, five kinds of multiple stimuli-responsive CPPs, three kinds of TME-responsive targeting CPPs, and two kinds of reversibly activatable CPPs (RACPPs) are systemically summarized. Then, TME-responsive CPPs for nanomedical applications are further discussed. Finally, we describe the translational applications of TME-responsive CPPs for anticancer drug delivery. These commentaries provide an insight into the design of next-generation activatable CPPs (ACPPs) for selective delivery of nanomedicines and anticancer drugs.

Noncanonical microprotein regulation of immunity

The immune system is highly regulated but, when dysregulated, suboptimal protective or overly robust immune responses can lead to immune-mediated disorders. The genetic and molecular mechanisms of immune regulation are incompletely understood, impeding the development of more precise diagnostics and therapeutics for immune-mediated disorders. Recently, thousands of previously unrecognized noncanonical microprotein genes encoded by small open reading frames have been identified. Many of these microproteins perform critical functions, often in a cell- and context-specific manner. Several microproteins are now known to regulate immunity; however, the vast majority are uncharacterized. Therefore, illuminating what is often referred to as the "dark proteome," may present opportunities to tune immune responses more precisely. Here, we review noncanonical microprotein biology, highlight recently discovered examples regulating immunity, and discuss the potential and challenges of modulating dysregulated immune responses by targeting microproteins.

Towards Cell-Permeable Hepatitis B Virus Core Protein Variants as Potential Antiviral Agents

Hepatitis B virus (HBV) infection remains a major health threat with limited treatment options. One of various new antiviral strategies is based on a fusion of Staphylococcus aureus nuclease (SN) with the capsid-forming HBV core protein (HBc), termed coreSN. Through co-assembly with wild-type HBc-subunits, the fusion protein is incorporated into HBV nucleocapsids, targeting the nuclease to the encapsidated viral genome. However, coreSN expression was based on transfection of a plasmid vector. Here, we explored whether introducing protein transduction domains (PTDs) into a fluorescent coreSN model could confer cell-penetrating properties for direct protein delivery into cells. Four PTDs were inserted into two different positions of the HBc sequence, comprising the amphiphilic translocation motif (TLM) derived from the HBV surface protein PreS2 domain and three basic PTDs derived from the Tat protein of human immunodeficiency virus-1 (HIV-1), namely Tat4, NP, and NS. To directly monitor the interaction with cells, the SN in coreSN was replaced with the green fluorescent protein (GFP). The fusion proteins were expressed in E. coli, and binding to and potential uptake by human cells was examined through flow cytometry and fluorescence microscopy. The data indicate PTD-dependent interactions with the cells, with evidence of uptake in particular for the basic PTDs. Uptake was enhanced by a triplicated Simian virus 40 (SV40) large T antigen nuclear localization signal (NLS). Interestingly, the basic C terminal domain of the HBV core protein was found to function as a novel PTD. Hence, further developing cell-permeable viral capsid protein fusions appears worthwhile.

Intracellular delivery strategies using membrane-interacting peptides and proteins

While the cellular cytosol and organelles contain attractive targets for disease treatments, it remains a challenge to deliver therapeutic biomacromolecules to these sites. This is due to the selective permeability of the plasma and endosomal membranes, especially for large and hydrophilic therapeutic cargos such as proteins and nucleic acids. In response, many different delivery systems and molecules have been devised to help therapeutics cross these barriers to reach cytosolic targets. Among them are peptide and protein-based systems, which have several advantages over other natural and synthetic materials including their ability to interact with cell membranes. In this review, we will describe recent advances and current challenges of peptide and protein strategies that leverage cell membrane association and modulation to enable cytosolic delivery of biomacromolecule cargo. The approaches covered here include peptides and proteins derived from or inspired by natural sequences as well as those designed de novo for delivery function.

Advances in Peptide-Decorated Targeted Drug Delivery: Exploring Therapeutic Potential and Nanocarrier Strategies

Peptides are ideal biologicals for targeted drug delivery and have also been increasingly employed as theranostic tools in treating various diseases, including cancer, with minimal or no side effects. Owing to their receptor-specificity, peptide-mediated drug delivery aids in targeted drug delivery with better pharmacological biodistribution. Nanostructured self-assembled peptides and peptide-drug conjugates demonstrate enhanced stability and performance and captivating biological effects in comparison with conventional peptides. Moreover, they serve as valuable tools for establishing interfaces between drug carriers and biological systems, enabling the traversal of multiple biological barriers encountered by peptide-drug conjugates on their journeys to their intended targets. Peptide-based drugs play a pivotal role in the field of medicine and hold great promise for addressing a wide range of complex diseases such as cancer and autoimmune disorders. Nanotechnology has revolutionized the fields of medicine, biomedical engineering, biotechnology, and engineering sciences over the past two decades. With the help of nanotechnology, better delivery of peptides to the target site could be achieved by exploiting the small size, increased surface area, and passive targeting ability of the nanocarrier. Furthermore, nanocarriers also ensure safe delivery of the peptide moieties to the target site, protecting them from degradation. Nanobased peptide delivery systems would be of significant importance in the near future for the successful targeted and efficient delivery of peptides. This review focuses on peptide-drug conjugates and nanoparticle-mediated self-assembled peptide delivery systems in cancer therapeutics.

Covalent conjugation and non-covalent complexation strategies for intracellular delivery of proteins using cell-penetrating peptides

Therapeutic proteins provided new opportunities for patients and high sales volumes. However, they are formulated for extracellular targets. The lipophilic barrier of the plasma membrane renders the vast array of intracellular targets out of reach. Peptide-based delivery systems, namely cell-penetrating peptides (CPPs), have few safety concerns, and low immunogenicity, with control over administered doses. This study investigates CPP-based protein delivery systems by classifying them into CPP-protein "covalent conjugation" and CPP: protein "non-covalent complexation" categories. Covalent conjugates ensure the proximity of the CPP to the cargo, which can improve cellular uptake and endosomal escape. We will discuss various aspects of covalent conjugates through non-cleavable (stable) or cleavable bonds. Non-cleavable CPP-protein conjugates are produced by recombinant DNA technology to express the complete fusion protein in a host cell or by chemical ligation of CPP and protein, which ensures stability during the delivery process. CPP-protein cleavable bonds are classified into pH-sensitive and redox-sensitive bonds, enzyme-cleavable bonds, and physical stimuli cleavable linkers (light radiation, ultrasonic waves, and thermo-responsive). We have highlighted the key characteristics of non-covalent complexes through electrostatic and hydrophobic interactions to preserve the conformational integrity of the CPP and cargo. CPP-mediated protein delivery by non-covalent complexation, such as zippers, CPP adaptor methods, and avidin-biotin technology, are featured. Conclusively, non-covalent complexation methods are appropriate when a high number of CPP or protein samples are to be screened. In contrast, when the high biological activity of the protein is critical in the intracellular compartment, conjugation protocols are preferred.

Porous protein crystals: synthesis and applications

Large-pore protein crystals (LPCs) are an emerging class of biomaterials. The inherent diversity of proteins translates to a diversity of crystal lattice structures, many of which display large pores and solvent channels. These pores can, in turn, be functionalized via directed evolution and rational redesign based on the known crystal structures. LPCs possess extremely high solvent content, as well as extremely high surface area to volume ratios. Because of these characteristics, LPCs continue to be explored in diverse applications including catalysis, targeted therapeutic delivery, templating of nanostructures, structural biology. This Feature review article will describe several of the existing platforms in detail, with particular focus on LPC synthesis approaches and reported applications.

Breaking Barriers: Nanomedicine-Based Drug Delivery for Cataract Treatment

Cataract is a leading cause of blindness globally, and its surgical treatment poses a significant burden on global healthcare. Pharmacologic therapies, including antioxidants and protein aggregation reversal agents, have attracted great attention in the treatment of cataracts in recent years. Due to the anatomical and physiological barriers of the eye, the effectiveness of traditional eye drops for delivering drugs topically to the lens is hindered. The advancements in nanomedicine present novel and promising strategies for addressing challenges in drug delivery to the lens, including the development of nanoparticle formulations that can improve drug penetration into the anterior segment and enable sustained release of medications. This review introduces various cutting-edge drug delivery systems for cataract treatment, highlighting their physicochemical properties and surface engineering for optimal design, thus providing impetus for further innovative research and potential clinical applications of anti-cataract drugs.

Peptide-Based Inhibitors of the Induced Signaling Protein Interactions: Current State and Prospects

Formation of the transient protein complexes in response to activation of cellular receptors is a common mechanism by which cells respond to external stimuli. This article presents the concept of blocking interactions of signaling proteins by the peptide inhibitors, and describes the progress achieved to date in the development of signaling inhibitors that act by blocking the signal-dependent protein interactions.

Nature-inspired peptide of MtDef4 C-terminus tail enables protein delivery in mammalian cells

Cell-penetrating peptides show promise as versatile tools for intracellular delivery of therapeutic agents. Various peptides have originated from natural proteins with antimicrobial activity. We investigated the mammalian cell-penetrating properties of a 16-residue peptide with the sequence GRCRGFRRRCFCTTHC from the C-terminus tail of the Medicago truncatula defensin MtDef4. We evaluated the peptide's ability to penetrate multiple cell types. Our results demonstrate that the peptide efficiently penetrates mammalian cells within minutes and at a micromolar concentration. Moreover, upon N-terminal fusion to the fluorescent protein GFP, the peptide efficiently delivers GFP into the cells. Despite its remarkable cellular permeability, the peptide has only a minor effect on cellular viability, making it a promising candidate for developing a cell-penetrating peptide with potential therapeutic applications.

Virtual Screening of Peptide Libraries: The Search for Peptide-Based Therapeutics Using Computational Tools

Over the last few decades, we have witnessed growing interest from both academic and industrial laboratories in peptides as possible therapeutics. Bioactive peptides have a high potential to treat various diseases with specificity and biological safety. Compared to small molecules, peptides represent better candidates as inhibitors (or general modulators) of key protein-protein interactions. In fact, undruggable proteins containing large and smooth surfaces can be more easily targeted with the conformational plasticity of peptides. The discovery of bioactive peptides, working against disease-relevant protein targets, generally requires the high-throughput screening of large libraries, and in silico approaches are highly exploited for their low-cost incidence and efficiency. The present review reports on the potential challenges linked to the employment of peptides as therapeutics and describes computational approaches, mainly structure-based virtual screening (SBVS), to support the identification of novel peptides for therapeutic implementations. Cutting-edge SBVS strategies are reviewed along with examples of applications focused on diverse classes of bioactive peptides (i.e., anticancer, antimicrobial/antiviral peptides, peptides blocking amyloid fiber formation).

Strategies to Enhance the Solubility and Bioavailability of Tocotrienols Using Self-Emulsifying Drug Delivery System

Tocotrienols have higher medicinal value, with multiple sources of evidence showing their biological properties as antioxidant, anti-inflammatory, and osteoprotective compounds. However, tocotrienol bioavailability presents an ongoing challenge in its translation into viable products. This is because tocotrienol oil is known to be a poorly water-soluble compound, making it difficult to be absorbed into the body and resulting in less effectiveness. With the potential and benefits of tocotrienol, new strategies to increase the bioavailability and efficacy of poorly absorbed tocotrienol are required when administered orally. One of the proposed formulation techniques was self-emulsification, which has proven its capacity to improve oral drug delivery of poorly water-soluble drugs by advancing the solubility and bioavailability of these active compounds. This review discusses the updated evidence on the bioavailability of tocotrienols formulated with self-emulsifying drug delivery systems (SEDDSs) from in vivo and human studies. In short, SEDDSs formulation enhances the solubility and passive permeability of tocotrienol, thus improving its oral bioavailability and biological actions. This increases its medicinal and commercial value. Furthermore, the self-emulsifying formulation presents a useful dosage form that is absorbed in vivo independent of dietary fats with consistent and enhanced levels of tocotrienol isomers. Therefore, a lipid-based formulation technique can provide an additional detailed understanding of the oral bioavailability of tocotrienols.

A Nucleus-Targeting WT1 Antagonistic Peptide Encapsulated in Polymeric Nanomicelles Combats Refractory Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) is recognized as a classic clonal myeloproliferative disorder. Given the limited treatment options for CML patients in the accelerated phase (AP) and blast phase (BP), there is an evident need to develop new therapeutic strategies. This has the potential to improve outcomes for individuals in the advanced stages of CML. A promising therapeutic target is Wilms' tumor 1 (WT1), which is highly expressed in BP-CML cells and plays a crucial role in CML progression. In this study, a chemically synthesized nucleus-targeting WT1 antagonistic peptide termed WIP2W was identified. The therapeutic implications of both the peptide and its micellar formulation, M-WIP2W, were evaluated in WT1+ BP-CML cell lines and in mice. The findings indicate that WIP2W can bind specifically to the WT1 protein, inducing cell cycle arrest and notable cytotoxicity in WT1+ BP-CML cells. Moreover, subcutaneous injections of M-WIP2W were observed to significantly enhance intra-tumoral accumulation and to effectively inhibit tumor growth. Thus, WIP2W stands out as a potent and selective WT1 inhibitor, and the M-WIP2W nanoformulation appears promising for the therapeutic treatment of refractory CML as well as other WT1-overexpressing malignant cancers.