Integrin-targeted AmpRGD sunitinib liposomes as integrated antiangiogenic tools

Shell-Sheddable Dendritic Polyglycerol Sulfates Loaded with Sunitinib for Inhibition of Tumor Angiogenesis

Induced angiogenesis, a specific hallmark of cancer, plays a vital role in tumor progression and can be targeted by inhibitors like sunitinib. Sunitinib is a small hydrophobic molecule suffering from low bioavailability and a short half-life in the bloodstream. To overcome these drawbacks, suitable drug delivery systems need to be developed. In this work dendritic polyglycerol (dPG), a well-known polymer, was functionalized with a sheddable shell. Therefore, aliphatic chains of different lengths (C₅, C₉, C₁₁) were coupled to dPG through a cleavable ester bond. To restore water solubility and improve tumor targeting, the surface was decorated with sulfate groups. The resulting shell-sheddable dPG sulfates were characterized and evaluated regarding their loading capacity and biocompatibility in cell culture. The nine-carbon chain derivative (dPG-TNS) was selected as the best candidate for further experiments due to its high drug loading capacity (20wt%), and a sustained release in vitro. The cellular biocompatibility of the blank carrier up to 1mg/mL was confirmed after 24h incubation on HeLa cells. Furthermore, the shell-cleavability of dPG-TNS under different physiological conditions was shown in a degradation study over four weeks. The activity of sunitinib-loaded dPG-TNS was demonstrated in a tube formation assay on Human umbilical vein endothelial cells (HUVECs). Our results suggest that the drug-loaded nanocarrier is a promising candidate to be further investigated in tumor treatments, as it shows similar efficacy to free sunitinib while overcoming its limitations.

Protein Corona Attenuates the Targeting of Antitumor Sialyl Lewis X-Decorated Liposomes to Vascular Endothelial Cells under Flow Conditions

Previously, we showed in the human umbilical vein endothelial cells (HUVECs) model that a liposome formulation of melphalan lipophilic prodrug (MlphDG) decorated with selectin ligand tetrasaccharide Sialyl Lewis X (SiaLe^X) undergoes specific uptake by activated cells and in an in vivo tumor model causes a severe antivascular effect. Here, we cultured HUVECs in a microfluidic chip and then applied the liposome formulations to study their interactions with the cells in situ under hydrodynamic conditions close to capillary blood flow using confocal fluorescent microscopy. The incorporation of 5 to 10% SiaLe^X conjugate in the bilayer of MlphDG liposomes increased their consumption exclusively by activated endotheliocytes. The increase of serum concentration from 20 to 100% in the flow resulted in lower liposome uptake by the cells. To elucidate the possible roles of plasma proteins in the liposome-cell interactions, liposome protein coronas were isolated and analyzed by shotgun proteomics and immunoblotting of selected proteins. Proteomic analysis showed that a gradual increase in SiaLe^X content correlated with the overall enrichment of the liposome-associated proteins with several apolipoproteins, including the most positively charged one, ApoC1, and serum amyloid A4, associated with inflammation, on the one hand, and a decrease in the content of bound immunoglobulins, on the other. The article discusses the potential interference of the proteins in the binding of liposomes to selectins of endothelial cells.

Enhanced In Vitro and In Vivo Anticancer Activity Through the Development of Sunitinib-Loaded Nanoniosomes with Controlled Release and Improved Uptake

This study aims to develop sunitinib niosomal formulations and assess their in-vitro anti-cancer efficiency against lung cancer cell line, A549. Sunitinib, a highly effective anticancer drug, was loaded in the niosome with high encapsulation efficiency. Collagen was coated on the surface of the niosome for enhanced cellular uptake and prolonged circulation time. Different formulations were produced, while response surface methodology was utilized to optimize the formulations. The stability of the formulations was evaluated over a 2-month period, revealing the importance of collagen coating. MTT assay demonstrated dose-dependent cytotoxicity for all formulations against lung cancer cells. Scratch assay test suggested antiproliferative efficacy of the formulations. The flow cytometry data confirmed the improved cytotoxicity with enhanced apoptosis rate when different formulations used. The 2D fluorescent images proved the presence of drug-containing niosomes in the tumor cells. The activation of the apoptotic pathway leading to protein synthesis was confirmed using an ELISA assay, which specifically evaluated the presence of cas3 and cas7. The results of this study indicated the antiproliferative efficacy of optimized niosomal formulations and their mechanism of action. Therefore, niosomes could be utilized as a suitable carrier for delivering sunitinib into lung cancer cells, paving the way for future clinical studies.

In vitro assessment of varying peptide surface density on the suppression of angiogenesis by micelles displaying αvβ3 blocking peptides

Ligand targeted therapy (LTT) is a precision medicine strategy that can selectively target diseased cells while minimizing off-target effects on healthy cells. Integrin-targeted LTT has been developed recently for angiogenesis-related diseases. However, the clinical success is based on the optimal design of the nanoparticles for inducing receptor clustering within the cell membrane. The current study focused on determining the surface density of Ser-Asp-Val containing anti-integrin heptapeptide on poly (ethylene glycol)-b-poly(propylene sulfide) micelles (MC) required for anti-angiogenic effects on HUVECs. Varying peptide density on PEG-b-PPS/Pep-PA MCs (Pep-PA-Peptide-palmitoleic acid) was used in comparison to a random peptide (SGV) and cRGD (cyclic-Arginine-Glycine-Aspartic acid) construct at 5%-density on MCs. Immunocytochemistry using CD51/CD31 antibody was performed to study the integrin blocking by MCs. In addition, the expression of VWF and PECAM-1, cell migration and tube formation was evaluated in the presence of PEG-b-PPS/Pep-PA MCs. The results show PEG-b-PPS/SDV-PA MCs with 5%-peptide density to achieve significantly higher αvβ3 blocking compared to random peptide as well as cRGD. In addition, αvβ3 blocking via MCs further reduced the expression of vWF and PECAM-1 angiogenesis protein expression in HUVECs. Although a significant level of integrin blocking was observed for 1%-peptide density on MCs, the cell migration and tube formation were not significantly affected. In conclusion, the results of this study demonstrate that the peptide surface density on PEG-b-PPS/Pep-PA MCs has a significant impact in integrin blocking as well as inhibiting angiogenesis during LTT. The outcomes of this study provides insight into the design of ligand targeted nanocarriers for various disease conditions.

Insights into Lipid-Based Delivery Nanosystems of Protein-Tyrosine Kinase Inhibitors for Cancer Therapy

According to the WHO, cancer caused almost 10 million deaths worldwide in 2020, i.e., almost one in six deaths. Among the most common are breast, lung, colon and rectal and prostate cancers. Although the diagnosis is more perfect and spectrum of available drugs is large, there is a clear trend of an increase in cancer that ends fatally. A major advance in treatment was the introduction of gentler antineoplastics for targeted therapy-tyrosine kinase inhibitors (TKIs). Although they have undoubtedly revolutionized oncology and hematology, they have significant side effects and limited efficacy. In addition to the design of new TKIs with improved pharmacokinetic and safety profiles, and being more resistant to the development of drug resistance, high expectations are placed on the reformulation of TKIs into various drug delivery lipid-based nanosystems. This review provides an insight into the history of chemotherapy, a brief overview of the development of TKIs for the treatment of cancer and their mechanism of action and summarizes the results of the applications of self-nanoemulsifying drug delivery systems, nanoemulsions, liposomes, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles and nanostructured lipid carriers used as drug delivery systems of TKIs obtained in vitro and in vivo.

Recent advances of nanomaterial-based anti-angiogenic therapy in tumor vascular normalization and immunotherapy

Anti-angiogenesis therapy and immunotherapy are the first-line therapeutic strategies for various tumor treatments in the clinic, bringing significant advantages for tumor patients. Recent studies have shown that anti-angiogenic therapy can potentiate immunotherapy, with many clinical trials conducted based on the combination of anti-angiogenic agents and immune checkpoint inhibitors (ICIs). However, currently available clinical dosing strategies and tools are limited, emphasizing the need for more improvements. Although significant progress has been achieved, several big questions remained, such as how to achieve cell-specific targeting in the tumor microenvironment? How to improve drug delivery efficiency in tumors? Can nanotechnology be used to potentiate existing clinical drugs and achieve synergistic sensitization effects? Over the recent few years, nanomedicines have shown unique advantages in antitumor research, including cell-specific targeting, improved delivery potentiation, and photothermal effects. Given that the applications of nanomaterials in tumor immunotherapy have been widely reported, this review provides a comprehensive overview of research advances on nanomaterials in anti-angiogenesis therapy, mainly focusing on the immunosuppressive effects of abnormal tumor vessels in the tumor immune microenvironment, the targets and strategies of anti-angiogenesis nanomedicines, and the potential synergistic effects and molecular mechanisms of anti-angiogenic nanomedicines in combination with immunotherapy, ultimately providing new perspectives on the nanomedicine-based synergy between anti-angiogenic and immunotherapy.

Light-Triggered Efficient Sequential Drug Delivery of Biomimetic Nanosystem for Multimodal Chemo-, Antiangiogenic, and Anti-MDSC Therapy in Melanoma

In view of the multiple pathological hallmarks of tumors, nanosystems for the sequential delivery of various drugs whose targets are separately located inside and outside tumor cells are desired for improved cancer therapy. However, current sequential delivery is mainly achieved through enzyme- or acid-dependent degradation of the nanocarrier, which would be influenced by the heterogeneous tumor microenvironment, and unloading efficiency of the drug acting on the target outside tumor cells is usually unsatisfactory. Here, a light-triggered sequential delivery strategy based on a liposomal formulation of doxorubicin (DOX)-loaded small-sized polymeric nanoparticles (DOX-NP) and free sunitinib in the aqueous cavity, is developed. The liposomal membrane is doped with photosensitizer porphyrin-phospholipid (PoP) and hybridized with red blood cell membrane to confer biomimetic features. Near-infrared light-induced membrane permeabilization triggers the "ultrafast" and "thorough" release of sunitinib (100% release in 5 min) for antiangiogenic therapy and also myeloid-derived suppressor cell (MDSC) inhibition to reverse the immunosuppressive tumor environment. Subsequently, the small-sized DOX-NP liberated from the liposomes is more easily uptaken by tumor cells for improved immunogenic chemotherapy. RNA sequencing and immune-related assay indicates therapeutic immune enhancement. This light-triggered sequential delivery strategy demonstrates the potency in cancer multimodal therapy against multiple targets in different spatial positions in tumor microenvironment.

Functionalized Liposome and Albumin-Based Systems as Carriers for Poorly Water-Soluble Anticancer Drugs: An Updated Review

Cancer is one of the leading causes of death worldwide. In the available treatments, chemotherapy is one of the most used, but has several associated problems, namely the high toxicity to normal cells and the resistance acquired by cancer cells to the therapeutic agents. The scientific community has been battling against this disease, developing new strategies and new potential chemotherapeutic agents. However, new drugs often exhibit poor solubility in water, which led researchers to develop functionalized nanosystems to carry and, specifically deliver, the drugs to cancer cells, targeting overexpressed receptors, proteins, and organelles. Thus, this review is focused on the recent developments of functionalized nanosystems used to carry poorly water-soluble drugs, with special emphasis on liposomes and albumin-based nanosystems, two major classes of organic nanocarriers with formulations already approved by the U.S. Food and Drug Administration (FDA) for cancer therapeutics.

Tumor vasculature-targeting nanomedicines

Uncontrolled tumor growth and subsequent distant metastasis are highly dependent on an adequate nutrient supply from tumor blood vessels, which have relatively different pathophysiological characteristics from those of normal vasculature. Obviously, strategies targeting tumor vasculature, such as anti-angiogenic drugs and vascular disrupting agents, are attractive methods for cancer therapy. However, the off-target effects and high dose administration of these drug regimens critically restrict their clinical applications. In recent years, nanomedicines focused on tumor vasculature have been shown to be superior to traditional therapeutic methods and do not induce side effects. This review will first highlight the recent development of tumor vasculature-targeting nanomedicines from the following four aspects: 1) angiogenesis-inhibiting nanomedicines (AINs); 2) vasculature-disrupting nanomedicines (VDNs); 3) vasculature infarction nanomedicines (VINs); and 4) vasculature-regulating nanomedicines (VRNs). Furthermore, the design principles, limitations, and future directions are also discussed. STATEMENT OF SIGNIFICANCE: Based on the essential roles of tumor blood vessels, the therapeutic strategies targeting tumor vasculature have exhibited good clinical therapeutic outcomes. However, poor patient adherence to free drug administration limits their clinical usage. Nanomedicines have great potential to overcome the abovementioned obstacle. This review summarizes the tumor-vasculature targeting nanomedicines from four aspects: 1) angiogenesis-inhibiting nanomedicines (AINs); 2) vasculature-disrupting nanomedicines (VDNs); 3) vasculature infarction nanomedicines (VINs); and 4) vasculature regulating nanomedicines (VRNs). In addition, this review provides perspectives on this research field.

New 4-Aminoproline-Based Small Molecule Cyclopeptidomimetics as Potential Modulators of α4β1 Integrin

Integrin α₄β₁ belongs to the leukocyte integrin family and represents a therapeutic target of relevant interest given its primary role in mediating inflammation, autoimmune pathologies and cancer-related diseases. The focus of the present work is the design, synthesis and characterization of new peptidomimetic compounds that are potentially able to recognize α₄β₁ integrin and interfere with its function. To this aim, a collection of seven new cyclic peptidomimetics possessing both a 4-aminoproline (Amp) core scaffold grafted onto key α₄β₁-recognizing sequences and the (2-methylphenyl)ureido-phenylacetyl (MPUPA) appendage, was designed, with the support of molecular modeling studies. The new compounds were synthesized through SPPS procedures followed by in-solution cyclization maneuvers. The biological evaluation of the new cyclic ligands in cell adhesion assays on Jurkat cells revealed promising submicromolar agonist activity in one compound, namely, the c[Amp(MPUPA)Val-Asp-Leu] cyclopeptide. Further investigations will be necessary to complete the characterization of this class of compounds.

Enhanced Vasculogenic Capacity Induced by 5-Fluorouracil Chemoresistance in a Gastric Cancer Cell Line

Chemotherapy is still widely used as a coadjutant in gastric cancer when surgery is not possible or in presence of metastasis. During tumor evolution, gatekeeper mutations provide a selective growth advantage to a subpopulation of cancer cells that become resistant to chemotherapy. When this phenomenon happens, patients experience tumor recurrence and treatment failure. Even if many chemoresistance mechanisms are known, such as expression of ATP-binding cassette (ABC) transporters, aldehyde dehydrogenase (ALDH1) activity and activation of peculiar intracellular signaling pathways, a common and universal marker for chemoresistant cancer cells has not been identified yet. In this study we subjected the gastric cancer cell line AGS to chronic exposure of 5-fluorouracil, cisplatin or paclitaxel, thus selecting cell subpopulations showing resistance to the different drugs. Such cells showed biological changes; among them, we observed that the acquired chemoresistance to 5-fluorouracil induced an endothelial-like phenotype and increased the capacity to form vessel-like structures. We identified the upregulation of thymidine phosphorylase (TYMP), which is one of the most commonly reported mutated genes leading to 5-fluorouracil resistance, as the cause of such enhanced vasculogenic ability.

Progresses in polymeric nanoparticles for delivery of tyrosine kinase inhibitors

Tyrosine kinase inhibitors (TKIs), as an important class of chemotherapeutic drugs, induce apoptosis by altering the path of the cellular signal, resulting in cell death. However, some chemotherapeutic drugs have a limited therapeutic index and are usually destructive as well as unpredictable. In addition, the limitation of early diagnosis and inefficiency of some of the drugs in ordinary treatments lead to disease progression and decreases in the survival of cancer patients. For this purpose, various methods have been proposed, among them, nanomedicine has transpired as a modern approach for the treatment of multiple cancers. Over the last two decades, targeted therapy has been developed for cancer-specific cells/tissues and has rather restricted nonselective toxicities. In vivo and in vitro studies demonstrated nanoparticles (NPs), nano-scale drugs, and nano-carriers alone or in combination with other therapeutic, imaging, and theranostic agents would be applied as an effective approach targeting a diversity of malignant tissue. Therefore, using the latest advances in materials science and biomaterials, biology, it has happened that general diagnosis and treatment can be performed. In this review, we indicated the applications of theranostic nano-polymer and nano-liposome to TKIs delivery.

Engineered nanomedicines for tumor vasculature blockade therapy

Tumor vasculature blockade therapy (TVBT), including angiogenesis inhibition, vascular disruption, and vascular infarction, provides a promising treatment modality for solid tumors. However, low selectivity, drug resistance, and possible severe side effects have limited the clinical transformation of TVBT. Engineered nanoparticles offer potential solutions, including prolonged circulation time, targeted transportation, and controlled release of TVBT agents. Moreover, engineered nanomedicines provide a promising combination platform of TVBT with chemotherapy, radiotherapy, photodynamic therapy, photothermal therapy, ultrasound therapy, and gene therapy. In this article, we offer a comprehensive summary of the current progress of engineered nanomedicines for TVBT and also discuss current deficiencies and future directions for TVBT development. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Nanomedicine of tyrosine kinase inhibitors

Recent progress in nanomedicine and targeted therapy brings new breeze into the field of therapeutic applications of tyrosine kinase inhibitors (TKIs). These drugs are known for many side effects due to non-targeted mechanism of action that negatively impact quality of patients' lives or that are responsible for failure of the drugs in clinical trials. Some nanocarrier properties provide improvement of drug efficacy, reduce the incidence of adverse events, enhance drug bioavailability, helps to overcome the blood-brain barrier, increase drug stability or allow for specific delivery of TKIs to the diseased cells. Moreover, nanotechnology can bring new perspectives into combination therapy, which can be highly efficient in connection with TKIs. Lastly, nanotechnology in combination with TKIs can be utilized in the field of theranostics, i.e. for simultaneous therapeutic and diagnostic purposes. The review provides a comprehensive overview of advantages and future prospects of conjunction of nanotransporters with TKIs as a highly promising approach to anticancer therapy.

Not just a fluidifying effect: omega-3 phospholipids induce formation of non-lamellar structures in biomembranes

Polyunsaturated omega-3 fatty acid docosahexaenoic acid (DHA) is found in very high concentrations in a few peculiar tissues, suggesting that it must have a specialized role. DHA was proposed to affect the function of the cell membrane and related proteins through an indirect mechanism of action, based on the DHA-phospholipid effects on the lipid bilayer structure. In this respect, most studies have focused on its influence on lipid-rafts, somehow neglecting the analysis of effects on liquid disordered phases that constitute most of the cell membranes, by reporting in these cases only a general fluidifying effect. In this study, by combining neutron reflectivity, cryo-transmission electron microscopy, small angle neutron scattering, dynamic light scattering and electron paramagnetic resonance spectroscopy, we characterize liquid disordered bilayers formed by the naturally abundant 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and different contents of a di-DHA glycero-phosphocholine, 22:6-22:6PC, from both a molecular/microscopic and supramolecular/mesoscopic viewpoint. We show that, below a threshold concentration of about 40% molar percent, incorporation of 22:6-22:6PC in the membrane increases the lipid dynamics slightly but sufficiently to promote the membrane deformation and increase of multilamellarity. Notably, beyond this threshold, 22:6-22:6PC disfavours the formation of lamellar phases, leading to a phase separation consisting mostly of small spherical particles that coexist with a minority portion of a lipid blob with water-filled cavities. Concurrently, from a molecular viewpoint, the polyunsaturated acyl chains tend to fold and expose the termini to the aqueous medium. We propose that this peculiar tendency is a key feature of the DHA-phospholipids making them able to modulate the local morphology of biomembranes.

Integrin-Targeting Peptides for the Design of Functional Cell-Responsive Biomaterials

Integrins are a family of cell surface receptors crucial to fundamental cellular functions such as adhesion, signaling, and viability, deeply involved in a variety of diseases, including the initiation and progression of cancer, of coronary, inflammatory, or autoimmune diseases. The natural ligands of integrins are glycoproteins expressed on the cell surface or proteins of the extracellular matrix. For this reason, short peptides or peptidomimetic sequences that reproduce the integrin-binding motives have attracted much attention as potential drugs. When challenged in clinical trials, these peptides/peptidomimetics let to contrasting and disappointing results. In the search for alternative utilizations, the integrin peptide ligands have been conjugated onto nanoparticles, materials, or drugs and drug carrier systems, for specific recognition or delivery of drugs to cells overexpressing the targeted integrins. Recent research in peptidic integrin ligands is exploring new opportunities, in particular for the design of nanostructured, micro-fabricated, cell-responsive, stimuli-responsive, smart materials.

Surface engineering of nanomaterials with phospholipid-polyethylene glycol-derived functional conjugates for molecular imaging and targeted therapy

In recent years, phospholipid-polyethylene glycol-derived functional conjugates have been widely employed to decorate different nanomaterials, due to their excellent biocompatibility, long blood circulation characteristics, and specific targeting capability. Numerous in vivo studies have demonstrated that nanomedicines peripherally engineered with phospholipid-polyethylene glycol-derived functional conjugates show significantly increased selective and efficient internalization by target cells/tissues. Targeting moieties including small-molecule ligands, peptides, proteins, and antibodies are generally conjugated onto PEGylated phospholipids to decorate liposomes, micelles, hybrid nanoparticles, nanocomplexes, and nanoemulsions for targeted delivery of diagnostic and therapeutic agents to diseased sites. In this review, the synthesis methods of phospholipid-polyethylene glycol-derived functional conjugates, biophysicochemical properties of nanomedicines decorated with these conjugates, factors dominating their targeting efficiency, as well as their applications for in vivo molecular imaging and targeted therapy were summarized and discussed.