Overcoming Biological Barriers With Block Copolymers-Based Self-Assembled Nanocarriers. Recent Advances in Delivery of Anticancer Therapeutics

"Actual" peptide properties required for nanoparticle development in precision cancer therapeutic delivery

Functionalizing nanoparticles with peptides (3-30 amino acids) reduces premature clearance and increases colloidal stability and targeting capacity of cancer therapeutics. Glutamate/lysine-rich zwitterionic and hydrophilic/neutral peptides minimize reticuloendothelial digestion of nanomedicine through reducing particle hydrophobicity and depressing plasma anti-PEG immunoglobulin that disrupts the PEG-based particle stealth. Anionic peptides negate protein corona formation and subsequent particle aggregation in vivo enabling efficient nanoparticles biodistribution and drug targeting by facilitating their endothelial/extracellular matrix pore diffusion. Cationic and hydrophobic peptides display a strong affinity for anionic cancer cell membrane and mediate membrane porosification or receptor binding leading to particle uptake and endocytosis. The peptide ionic and hydrophobicity/hydrophilicity attributes collectively facilitate endosomal escape, and nuclear and mitochondria targeting of nanoparticles. Peptides are required to present with different physicochemical attributes from administration site, through blood and extracellular matrix, to cancer site of action. Charge/hydrophilicity-hydrophobicity switching and projection of receptor-specific domain of peptides are attainable through pH-pKa interplay and labile bond hydrolysis of "unwanted" domain to give rise to new functional domains in response to pH, thermal and enzymatic stimuli. Co-introducing all functional attributes on a single peptide is challenging. Use of peptide blends risks leaching during nanoparticles production. Peptides-nanoparticles conjugation risks peptide conformational alterations and loss of acidic/basic termini affecting their roles in nanoparticle stabilization, targeting, membrane permeabilization and subcellular delivery.

Next-generation cancer nanotherapeutics: Pluronic® F127 based mixed micelles for enhanced drug delivery

Cancer, projected to become the second leading cause of mortality globally, underscores the critical need for precise drug delivery systems. Nanotechnology, particularly micelles, has emerged as a promising avenue. These nano-sized colloidal dispersions (< 100 nm) utilize amphiphilic molecules featuring a hydrophilic tail and hydrophobic core, facilitating efficient drug encapsulation and delivery. Pluronic® F127, a triblock copolymer (PEO101-PPO56-PEO101), has emerged as a promising drug carrier due to its non-ionic, less-toxic nature, which prolongs drug circulation time and improves drug delivery across blood-brain and intestinal barriers. Mixed micelles, formed using Pluronic® F127 combined with other polymers, surfactants, and drugs, enhance drug solubility, stability, and targeted delivery. This review highlights the key features of mixed micelles, including enhanced pharmacokinetics and targeting abilities, folic acid (FA) conjugation strategies, superior cytotoxicity with reduced side effects, overcoming multidrug resistance, and versatility across various cancer types and compounds. Additionally, the potential for clinical translation of Pluronic® F127-based mixed micelle in cancer treatment is discussed, addressing current challenges and paving the way for optimized applications.

Precision targeting of fat metabolism in triple negative breast cancer with a biotinylated copolymer

Mitochondrial CPT1-mediated fatty acid β-oxidation (FAO) critically contributes to the accelerated metastatic expansion of triple negative breast cancer (TNBC). Hence, inhibition of FAO through active CPT1 targeting could be a promising therapeutic approach in anti-TNBC therapies. Herein, we strategically synthesized a pyrene chain end labelled copolymer bearing biotin pendants, CP4, that actively targets CPT1 and efficiently blocks FAO in metastatic TNBC. Following the comprehensive characterization and synthesis of CP4, in silico negative docking score and Ramachandran plot analyses confirmed its on-target binding potential to CPT1. As a result, CP4 disrupts mitochondrial membrane potential, generates excessive ROS, and restricts excessive ATP production by impairing mitochondrial respiration, glycolytic function, and FAO. Subsequently, CP4 suppressed FA uptake and regulated FAO-associated gene expressions, exhibiting successive metastatic growth inhibition and apoptosis induction. Also, in an animal model, CP4 demonstrated active binding to CPT1, as evidenced by the significant depletion of CPT1A expression in tumor and liver tissue, akin to the specific CPT1-targeted drug. This active targeting of CPT1 has further consolidated the healing of altered lipid and oxidative stress, resulting in remarkable tumor regression, highlighting CP4 as a promising anticancer therapy focused on mitochondrial FAO, advancing future breast cancer treatments.

2D Hetero-Nanoconstructs of Black Phosphorus for Breast Cancer Theragnosis: Technological Advancements

As per global cancer statistics of 2020, female breast cancer is the most commonly diagnosed cancer and also the foremost cause of cancer death in women. Traditional treatments include a number of negative effects, making it necessary to investigate novel smart drug delivery methods and identify new therapeutic approaches. Efforts for developing novel strategies for breast cancer therapy are being devised worldwide by various research groups. Currently, two-dimensional black phosphorus nanosheets (BPNSs) have attracted considerable attention and are best suited for theranostic nanomedicine. Particularly, their characteristics, including drug loading efficacy, biocompatibility, optical, thermal, electrical, and phototherapeutic characteristics, support their growing demand as a potential substitute for graphene-based nanomaterials in biomedical applications. In this review, we have explained different platforms of BP nanomaterials for breast cancer management, their structures, functionalization approaches, and general methods of synthesis. Various characteristics of BP nanomaterials that make them suitable for cancer therapy and diagnosis, such as large surface area, nontoxicity, solubility, biodegradability, and excellent near-infrared (NIR) absorption capability, are discussed in the later sections. Next, we summarize targeting approaches using various strategies for effective therapy with BP nanoplatforms. Then, we describe applications of BP nanomaterials for breast cancer treatment, which include drug delivery, codelivery of drugs, photodynamic therapy, photothermal therapy, combined therapy, gene therapy, immunotherapy, and multidrug resistance reversal strategy. Finally, the present challenges and future aspects of BP nanomaterials are discussed.

pH-temperature dual-sensitive nucleolipid-containing stealth liposomes anchored with PEGylated AuNPs for triggering delivery of doxorubicin

Liposomes (Lip) are useful nanocarriers for drug delivery and cancer nanomedicine because of their ability to efficiently encapsulate drugs with different physical and chemical properties. The pH gradient between normal and tumoral tissues, and their rapid metabolism that induces hyperthermia encourage the development of pH- and thermo-sensitive Lip for delivering anticancer drugs. Nucleolipids have been studied as scaffolding material to prepare Lip, mainly for cancer therapy. Herein, we report for the first time the use of 1,2-dipalmitoyl-sn-glycero-3-(cytidine diphosphate) (DG-CDP) to develop pH/thermo-sensitive nucleolipid-containing stealth Lip stabilized by combination with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cholesterol, anchored with NH₂-PEGylated gold nanoparticles (PEG-AuNPs, 15 nm) for triggering delivery of doxorubicin (Dox). The optimal composition of DPPC, DG-CDP and cholesterol (94:3:3) was established by Langmuir isotherms. Unloaded and Dox-loaded Lip and AuNPs-Lip exhibited nano-scale sizes (415-650 nm), acceptable polydispersity indexes (<0.33), spherical shapes, and negative Z-potential (-23- -6.6 mV) due to the phosphate groups of DG-CDP, which allowed the anchoring with positively charged AuNPs. High EE% were achieved (>78%) and although efficient control in the Dox release towards different receptor media was observed, the release of Dox from PEG-AuNPs-Lip-Dox was significantly triggered at acidic pH and hyperthermia temperature, demonstrating its responsiveness to both stimuli. Dox-loaded Lip showed high cytotoxic activity against MDA-MB-231 breast cancer cells and SK-OV-3 ovarian cancer cells, suggesting that Dox was released from these nanocarriers over time. Overall, the liposomal formulations showed promising properties as stimuli-responsive nanocarriers for cancer nanomedicine, with prospects for hyperthermia therapy.

Polymeric Nanostructures Containing Proteins and Peptides for Pharmaceutical Applications

Over the last three decades, proteins and peptides have attracted great interest as drugs of choice for combating a broad spectrum of diseases, including diabetes mellitus, cancer, and infectious and neurological diseases. However, the delivery of therapeutic proteins to target sites should take into account the obstacles and limitations related to their intrinsic sensitivity to different environmental conditions, fragile tertiary structures, and short half-life. Polymeric nanostructures have emerged as competent vehicles for protein delivery, as they are multifunctional and can be tailored according to their peculiarities. Thus, the enhanced bioavailability and biocompatibility, the adjustable control of physicochemical features, and the colloidal stability of polymer-based nanostructures further enable either the embedding or conjugation of hydrophobic or hydrophilic bioactive molecules, which are some of the features of paramount importance that they possess and which contribute to their selection as vehicles. The present review aims to discuss the prevalent nanostructures composed of block copolymers from the viewpoint of efficient protein hospitality and administration, as well as the up-to-date scientific publications and anticipated applications of polymeric nanovehicles containing proteins and peptides.

Poly (β amino esters) copolymers: Novel potential vectors for delivery of genes and related therapeutics

The unique properties of polymers have performed an essential contribution to the drug delivery system by providing an outstanding platform for the delivery of macromolecules and genes. However, the block copolymers have been the subject of many recently published works whose results have demonstrated excellent performance in drug targeting. Poly(β-amino esters) (PβAEs) copolymers are the synthetic cationic polymers that are tailored by chemically joining PβAEs with other additives to demonstrate extraordinary efficiency in designing pre-defined and pre-programmed nanostructures, site-specific delivery, andovercoming the distinct cellular barriers. Different compositional and structural libraries could be generated by combinatorial chemistry and by the addition of various novel functional additives that fulfill the multiple requirements of targeted delivery. These intriguing attributes allow PβAE-copolymers to have customized therapeutic functions such as excellent encapsulation capacity, high stability, and stimuli-responsive release. Here, we give an overview of PβAE copolymers-based formulations along with focusing on most notable improvements such as structural modifications, bio-conjugations, and stimuli-responsive approaches, for safe and effective nucleic acids delivery.

Pyridine-containing block copolymeric nano-assemblies obtained through complementary hydrogen-bonding directed polymerization-induced self-assembly in water

A diversity of pyridine-containing polymeric nanomaterials with controllable structures and multiple responses were developed through complementary hydrogen-bonding directed polymerization-induced self-assembly in aqueous solution.